WorldWideScience

Sample records for length scale related

  1. Kelvin Absolute Temperature Scale Identified as Length Scale and Related to de Broglie Thermal Wavelength

    Science.gov (United States)

    Sohrab, Siavash

    Thermodynamic equilibrium between matter and radiation leads to de Broglie wavelength λdβ = h /mβvrβ and frequency νdβ = k /mβvrβ of matter waves and stochastic definitions of Planck h =hk =mk c and Boltzmann k =kk =mk c constants, λrkνrk = c , that respectively relate to spatial (λ) and temporal (ν) aspects of vacuum fluctuations. Photon massmk =√{ hk /c3 } , amu =√{ hkc } = 1 /No , and universal gas constant Ro =No k =√{ k / hc } result in internal Uk = Nhνrk = Nmkc2 = 3 Nmkvmpk2 = 3 NkT and potential pV = uN\\vcirc / 3 = N\\ucirc / 3 = NkT energy of photon gas in Casimir vacuum such that H = TS = 4 NkT . Therefore, Kelvin absolute thermodynamic temperature scale [degree K] is identified as length scale [meter] and related to most probable wavelength and de Broglie thermal wavelength as Tβ =λmpβ =λdβ / 3 . Parallel to Wien displacement law obtained from Planck distribution, the displacement law λwS T =c2 /√{ 3} is obtained from Maxwell -Boltzmann distribution of speed of ``photon clusters''. The propagation speeds of sound waves in ideal gas versus light waves in photon gas are described in terms of vrβ in harmony with perceptions of Huygens. Newton formula for speed of long waves in canals √{ p / ρ } is modified to √{ gh } =√{ γp / ρ } in accordance with adiabatic theory of Laplace.

  2. Comparison of relativity theories with observer-independent scales of both velocity and length/mass

    International Nuclear Information System (INIS)

    Amelino-Camelia, Giovanni; Benedetti, Dario; D'Andrea, Francesco; Procaccini, Andrea

    2003-01-01

    We consider the two most studied proposals of relativity theories with observer-independent scales of both velocity and length/mass: the one discussed by Amelino-Camelia as an illustrative example for the original proposal (Preprint gr-qc/0012051) of theories with two relativistic invariants, and an alternative more recently proposed by Magueijo and Smolin (Preprint hep-th/0112090). We show that these two relativistic theories are much more closely connected than it would appear on the basis of a naive analysis of their original formulations. In particular, in spite of adopting a rather different formal description of the deformed boost generators, they end up assigning the same dependence of momentum on rapidity, which can be described as the core feature of these relativistic theories. We show that this observation can be used to clarify the concepts of particle mass, particle velocity and energy-momentum conservation rules in these theories with two relativistic invariants

  3. Age-related changes in the plasticity and toughness of human cortical bone at multiple length-scales

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, Elizabeth A.; Schaible, Eric; Bale, Hrishikesh; Barth, Holly D.; Tang, Simon Y.; Reichert, Peter; Busse, Bjoern; Alliston, Tamara; Ager III, Joel W.; Ritchie, Robert O.

    2011-08-10

    The structure of human cortical bone evolves over multiple length-scales from its basic constituents of collagen and hydroxyapatite at the nanoscale to osteonal structures at nearmillimeter dimensions, which all provide the basis for its mechanical properties. To resist fracture, bone’s toughness is derived intrinsically through plasticity (e.g., fibrillar sliding) at structural-scales typically below a micron and extrinsically (i.e., during crack growth) through mechanisms (e.g., crack deflection/bridging) generated at larger structural-scales. Biological factors such as aging lead to a markedly increased fracture risk, which is often associated with an age-related loss in bone mass (bone quantity). However, we find that age-related structural changes can significantly degrade the fracture resistance (bone quality) over multiple lengthscales. Using in situ small-/wide-angle x-ray scattering/diffraction to characterize sub-micron structural changes and synchrotron x-ray computed tomography and in situ fracture-toughness measurements in the scanning electron microscope to characterize effects at micron-scales, we show how these age-related structural changes at differing size-scales degrade both the intrinsic and extrinsic toughness of bone. Specifically, we attribute the loss in toughness to increased non-enzymatic collagen cross-linking which suppresses plasticity at nanoscale dimensions and to an increased osteonal density which limits the potency of crack-bridging mechanisms at micron-scales. The link between these processes is that the increased stiffness of the cross-linked collagen requires energy to be absorbed by “plastic” deformation at higher structural levels, which occurs by the process of microcracking.

  4. Mixing lengths scaling in a gravity flow

    Energy Technology Data Exchange (ETDEWEB)

    Ecke, Robert E [Los Alamos National Laboratory; Rivera, Micheal [Los Alamos National Laboratory; Chen, Jun [Los Alamos National Laboratory; Ecke, Robert E [Los Alamos National Laboratory

    2009-01-01

    We present an experimental study of the mixing processes in a gravity current. The turbulent transport of momentum and buoyancy can be described in a very direct and compact form by a Prandtl mixing length model [1]: the turbulent vertical fluxes of momentum and buoyancy are found to scale quadraticatly with the vertical mean gradients of velocity and density. The scaling coefficient is the square of the mixing length, approximately constant over the mixing zone of the stratified shear layer. We show in this paper how, in different flow configurations, this length can be related to the shear length of the flow {radical}({var_epsilon}/{partial_derivative}{sub z}u{sup 3}).

  5. Minimal Length Scale Scenarios for Quantum Gravity.

    Science.gov (United States)

    Hossenfelder, Sabine

    2013-01-01

    We review the question of whether the fundamental laws of nature limit our ability to probe arbitrarily short distances. First, we examine what insights can be gained from thought experiments for probes of shortest distances, and summarize what can be learned from different approaches to a theory of quantum gravity. Then we discuss some models that have been developed to implement a minimal length scale in quantum mechanics and quantum field theory. These models have entered the literature as the generalized uncertainty principle or the modified dispersion relation, and have allowed the study of the effects of a minimal length scale in quantum mechanics, quantum electrodynamics, thermodynamics, black-hole physics and cosmology. Finally, we touch upon the question of ways to circumvent the manifestation of a minimal length scale in short-distance physics.

  6. Minimal Length Scale Scenarios for Quantum Gravity

    Directory of Open Access Journals (Sweden)

    Sabine Hossenfelder

    2013-01-01

    Full Text Available We review the question of whether the fundamental laws of nature limit our ability to probe arbitrarily short distances. First, we examine what insights can be gained from thought experiments for probes of shortest distances, and summarize what can be learned from different approaches to a theory of quantum gravity. Then we discuss some models that have been developed to implement a minimal length scale in quantum mechanics and quantum field theory. These models have entered the literature as the generalized uncertainty principle or the modified dispersion relation, and have allowed the study of the effects of a minimal length scale in quantum mechanics, quantum electrodynamics, thermodynamics, black-hole physics and cosmology. Finally, we touch upon the question of ways to circumvent the manifestation of a minimal length scale in short-distance physics.

  7. Length-scale dependent phonon interactions

    CERN Document Server

    Srivastava, Gyaneshwar

    2014-01-01

    This book presents  a comprehensive description of phonons and their interactions in systems with different dimensions and length scales. Internationally-recognized leaders describe theories and measurements of phonon interactions  in relation to the design of materials with exotic properties such as metamaterials, nano-mechanical systems, next-generation electronic, photonic, and acoustic devices, energy harvesting, optical information storage, and applications of phonon lasers in a variety of fields. The emergence of techniques for control of semiconductor properties and geometry has enabled engineers to design structures in which functionality is derived from controlling electron behavior. As manufacturing techniques have greatly expanded the list of available materials and the range of attainable length scales, similar opportunities now exist for designing devices whose functionality is derived from controlling phonon behavior. However, progress in this area is hampered by gaps in our knowledge of phono...

  8. Topographical length scales of hierarchical superhydrophobic surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Dhillon, P.K. [Department of Physics, Indian Institute of Technology Ropar, Nangal Road, Rupnagar, Punjab 140001 (India); Brown, P.S.; Bain, C.D.; Badyal, J.P.S. [Department of Chemistry, Science Laboratories, Durham University, Durham DH1 3LE, England (United Kingdom); Sarkar, S., E-mail: sarkar@iitrpr.ac.in [Department of Physics, Indian Institute of Technology Ropar, Nangal Road, Rupnagar, Punjab 140001 (India)

    2014-10-30

    Highlights: • Hydrophobic CF{sub 4} plasma fluorinated polybutadiene surfaces has been characterised using AFM. • Micro, Nano, and Micro + Nano topographies generated by altering plasma power and duration. • Dynamic scaling theory and FFT analysis used to characterize these surfaces quantitatively. • Roughnesses are different for different length scales of the surfaces considered. • Highest local roughness obtained from scaling analysis for shorter length scales of about 500 nm explains the superhydrophobicity for the Micro + Nano surface. - Abstract: The morphology of hydrophobic CF{sub 4} plasma fluorinated polybutadiene surfaces has been characterised using atomic force microscopy (AFM). Judicious choice of the plasma power and exposure duration leads to formation of three different surface morphologies (Micro, Nano, and Micro + Nano). Scaling theory analysis shows that for all three surface topographies, there is an initial increase in roughness with length scale followed by a levelling-off to a saturation level. At length scales around 500 nm, it is found that the roughness is very similar for all three types of surfaces, and the saturation roughness value for the Micro + Nano morphology is found to be intermediate between those for the Micro and Nano surfaces. Fast Fourier Transform (FFT) analysis has shown that the Micro + Nano topography comprises a hierarchical superposition of Micro and Nano morphologies. Furthermore, the Micro + Nano surfaces display the highest local roughness (roughness exponent α = 0.42 for length scales shorter than ∼500 nm), which helps to explain their superhydrophobic behaviour (large water contact angle (>170°) and low hysteresis (<1°))

  9. The Extended Relativity Theory in Born-Clifford Phase Spaces with a Lower and Upper Length Scales and Clifford Group Geometric Unification

    CERN Document Server

    Castro, C

    2004-01-01

    We construct the Extended Relativity Theory in Born-Clifford-Phase spaces with an upper and lower length scales (infrared/ultraviolet cutoff). The invariance symmetry leads naturally to the real Clifford algebra Cl (2, 6, R ) and complexified Clifford Cl_C ( 4 ) algebra related to Twistors. We proceed with an extensive review of Smith's 8D model based on the Clifford algebra Cl ( 1 ,7) that reproduces at low energies the physics of the Standard Model and Gravity; including the derivation of all the coupling constants, particle masses, mixing angles, ....with high precision. Further results by Smith are discussed pertaining the interplay among Clifford, Jordan, Division and Exceptional Lie algebras within the hierarchy of dimensions D = 26, 27, 28 related to bosonic string, M, F theory. Two Geometric actions are presented like the Clifford-Space extension of Maxwell's Electrodynamics, Brandt's action related the 8D spacetime tangent-bundle involving coordinates and velocities (Finsler geometries) followed by a...

  10. Determining multiple length scales in rocks

    Science.gov (United States)

    Song, Yi-Qiao; Ryu, Seungoh; Sen, Pabitra N.

    2000-07-01

    Carbonate reservoirs in the Middle East are believed to contain about half of the world's oil. The processes of sedimentation and diagenesis produce in carbonate rocks microporous grains and a wide range of pore sizes, resulting in a complex spatial distribution of pores and pore connectivity. This heterogeneity makes it difficult to determine by conventional techniques the characteristic pore-length scales, which control fluid transport properties. Here we present a bulk-measurement technique that is non-destructive and capable of extracting multiple length scales from carbonate rocks. The technique uses nuclear magnetic resonance to exploit the spatially varying magnetic field inside the pore space itself-a `fingerprint' of the pore structure. We found three primary length scales (1-100µm) in the Middle-East carbonate rocks and determined that the pores are well connected and spatially mixed. Such information is critical for reliably estimating the amount of capillary-bound water in the rock, which is important for efficient oil production. This method might also be used to complement other techniques for the study of shaly sand reservoirs and compartmentalization in cells and tissues.

  11. Chemical theory and modelling through density across length scales

    International Nuclear Information System (INIS)

    Ghosh, Swapan K.

    2016-01-01

    One of the concepts that has played a major role in the conceptual as well as computational developments covering all the length scales of interest in a number of areas of chemistry, physics, chemical engineering and materials science is the concept of single-particle density. Density functional theory has been a versatile tool for the description of many-particle systems across length scales. Thus, in the microscopic length scale, an electron density based description has played a major role in providing a deeper understanding of chemical binding in atoms, molecules and solids. Density concept has been used in the form of single particle number density in the intermediate mesoscopic length scale to obtain an appropriate picture of the equilibrium and dynamical processes, dealing with a wide class of problems involving interfacial science and soft condensed matter. In the macroscopic length scale, however, matter is usually treated as a continuous medium and a description using local mass density, energy density and other related property density functions has been found to be quite appropriate. The basic ideas underlying the versatile uses of the concept of density in the theory and modelling of materials and phenomena, as visualized across length scales, along with selected illustrative applications to some recent areas of research on hydrogen energy, soft matter, nucleation phenomena, isotope separation, and separation of mixture in condensed phase, will form the subject matter of the talk. (author)

  12. Interplay between multiple length and time scales in complex ...

    Indian Academy of Sciences (India)

    Administrator

    micelles and enzymes, can span several orders of magnitude in length and time scales. The length and time scales of ... length and time scales is required in order to understand and predict structure and dynamics in such com- plex systems. This review .... The late 1980s saw the birth of femtochemistry with Ahmed Zewail ...

  13. Nano-regime Length Scales Extracted from the First Sharp Diffraction Peak in Non-crystalline SiO2 and Related Materials: Device Applications

    Directory of Open Access Journals (Sweden)

    Phillips James

    2010-01-01

    Full Text Available Abstract This paper distinguishes between two different scales of medium range order, MRO, in non-crystalline SiO2: (1 the first is ~0.4 to 0.5 nm and is obtained from the position of the first sharp diffraction peak, FSDP, in the X-ray diffraction structure factor, S(Q, and (2 the second is ~1 nm and is calculated from the FSDP full-width-at-half-maximum FWHM. Many-electron calculations yield Si–O third- and O–O fourth-nearest-neighbor bonding distances in the same 0.4–0.5 nm MRO regime. These derive from the availability of empty Si dπ orbitals for back-donation from occupied O pπ orbitals yielding narrow symmetry determined distributions of third neighbor Si–O, and fourth neighbor O–O distances. These are segments of six member rings contributing to connected six-member rings with ~1 nm length scale within the MRO regime. The unique properties of non-crystalline SiO2 are explained by the encapsulation of six-member ring clusters by five- and seven-member rings on average in a compliant hard-soft nano-scaled inhomogeneous network. This network structure minimizes macroscopic strain, reducing intrinsic bonding defects as well as defect precursors. This inhomogeneous CRN is enabling for applications including thermally grown ~1.5 nm SiO2 layers for Si field effect transistor devices to optical components with centimeter dimensions. There are qualitatively similar length scales in nano-crystalline HfO2 and phase separated Hf silicates based on the primitive unit cell, rather than a ring structure. Hf oxide dielectrics have recently been used as replacement dielectrics for a new generation of Si and Si/Ge devices heralding a transition into nano-scale circuits and systems on a Si chip.

  14. Length Scales in Bayesian Automatic Adaptive Quadrature

    Directory of Open Access Journals (Sweden)

    Adam Gh.

    2016-01-01

    Full Text Available Two conceptual developments in the Bayesian automatic adaptive quadrature approach to the numerical solution of one-dimensional Riemann integrals [Gh. Adam, S. Adam, Springer LNCS 7125, 1–16 (2012] are reported. First, it is shown that the numerical quadrature which avoids the overcomputing and minimizes the hidden floating point loss of precision asks for the consideration of three classes of integration domain lengths endowed with specific quadrature sums: microscopic (trapezoidal rule, mesoscopic (Simpson rule, and macroscopic (quadrature sums of high algebraic degrees of precision. Second, sensitive diagnostic tools for the Bayesian inference on macroscopic ranges, coming from the use of Clenshaw-Curtis quadrature, are derived.

  15. Length Scales in Bayesian Automatic Adaptive Quadrature

    Science.gov (United States)

    Adam, Gh.; Adam, S.

    2016-02-01

    Two conceptual developments in the Bayesian automatic adaptive quadrature approach to the numerical solution of one-dimensional Riemann integrals [Gh. Adam, S. Adam, Springer LNCS 7125, 1-16 (2012)] are reported. First, it is shown that the numerical quadrature which avoids the overcomputing and minimizes the hidden floating point loss of precision asks for the consideration of three classes of integration domain lengths endowed with specific quadrature sums: microscopic (trapezoidal rule), mesoscopic (Simpson rule), and macroscopic (quadrature sums of high algebraic degrees of precision). Second, sensitive diagnostic tools for the Bayesian inference on macroscopic ranges, coming from the use of Clenshaw-Curtis quadrature, are derived.

  16. On transition in plasma turbulence with multiple scale lengths

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, K.; Spineanu, F.; Vlad, M.O. [National Inst. for Fusion Science, Toki, Gifu (Japan); Itoh, S.-I.; Kawasaki, M. [Kyushu Univ., Research Institute for Applied Mechanics, Kasuga, Fukuoka (Japan)

    2003-05-01

    A statistical theory of plasma turbulence which is composed of multiple-scale fluctuations is examined. Influences of statistical noise and variance of rapidly-changing variable in an adiabatic approximation are investigated. It is confirmed that the contributions of noise and variance remain higher order corrections. Transition rate of the turbulence with multiple scale lengths is obtained under the refined adiabatic approximation. (author)

  17. Critical length scales for flow phenomena in liquid metal batteries

    Science.gov (United States)

    Kelley, Douglas; Weier, Tom

    2017-11-01

    Liquid metal batteries, a new technology for grid-scale energy storage, are composed of three liquid layers and therefore subject to a wide variety of fluid dynamical phenomena, both beneficial and detrimental. Some, like thermal convection and electrovortex flow, drive finite flow regardless of the size, current density, and temperature of the battery. Others, like the Tayler instability and the metal pad instability, occur only in certain parameter regimes - almost always dependent on length scale. I will discuss critical length scales, considering implications for battery design in light of fundamental fluid dynamics. This work was supported by the National Science Foundation under Award Number CBET-1552182.

  18. Maximum length scale in density based topology optimization

    DEFF Research Database (Denmark)

    Lazarov, Boyan Stefanov; Wang, Fengwen

    2017-01-01

    The focus of this work is on two new techniques for imposing maximum length scale in topology optimization. Restrictions on the maximum length scale provide designers with full control over the optimized structure and open possibilities to tailor the optimized design for broader range...... of manufacturing processes by fulfilling the associated technological constraints. One of the proposed methods is based on combination of several filters and builds on top of the classical density filtering which can be viewed as a low pass filter applied to the design parametrization. The main idea...

  19. Analysis Models for Polymer Composites Across Different Length Scales

    Science.gov (United States)

    Camanho, Pedro P.; Arteiro, Albertino

    This chapter presents the analysis models, developed at different length scales, for the prediction of inelastic deformation and fracture of polymer composite materials reinforced by unidirectional fibers. Three different length scales are covered. Micro-mechanical models are used to understand in detail the effects of the constituents on the response of the composite material, and to support the development of analysis models based on homogenized representations of composite materials. Meso-mechanical models are used to predict the strength of composite structural components under general loading conditions. Finally, macro-mechanical models based on Finite Fracture Mechanics, which enable fast strength predictions of simple structural details, are discussed.

  20. Length and time scales of atmospheric moisture recycling

    Directory of Open Access Journals (Sweden)

    R. J. van der Ent

    2011-03-01

    Full Text Available It is difficult to quantify the degree to which terrestrial evaporation supports the occurrence of precipitation within a certain study region (i.e. regional moisture recycling due to the scale- and shape-dependence of regional moisture recycling ratios. In this paper we present a novel approach to quantify the spatial and temporal scale of moisture recycling, independent of the size and shape of the region under study. In contrast to previous studies, which essentially used curve fitting, the scaling laws presented by us follow directly from the process equation. thus allowing a fair comparison between regions and seasons. The calculation is based on ERA-Interim reanalysis data for the period 1999 to 2008. It is shown that in the tropics or in mountainous terrain the length scale of recycling can be as low as 500 to 2000 km. In temperate climates the length scale is typically between 3000 to 5000 km whereas it amounts to more than 7000 km in desert areas. The time scale of recycling ranges from 3 to 20 days, with the exception of deserts, where it is much longer. The most distinct seasonal differences can be observed over the Northern Hemisphere: in winter, moisture recycling is insignificant, whereas in summer it plays a major role in the climate. The length and time scales of atmospheric moisture recycling can be useful metrics to quantify local climatic effects of land use change.

  1. Relation between axial length and ocular parameters

    Directory of Open Access Journals (Sweden)

    Xue-Qiu Yang

    2013-09-01

    Full Text Available AIM: To investigatethe relation between axial length(AL, age and ocular parameters.METHODS: A total of 360 subjects(360 eyeswith emmetropia or myopia were recruited. Refraction, center corneal thickness(CCT, AL, intraocular pressure(IOPwere measured by automatic-refractor, Pachymeter, A-mode ultrasound and non-contact tonometer, respectively. Corneal curvature(CC, anterior chamber depth(ACDand white-to-white distance(WWDwere measured by Orbscan II. Three dimensional frequency domain coherent optical tomography(3D-OCTwas used to examine the retinal nerve fiber layer thickness(RNFLT. The Pearson correlation coefficient(rand multiple regression analysis were performed to evaluate the relationship between AL, age and ocular parameters.RESULTS: The average AL was 24.15±1.26mm. With elongation of the AL, spherical equivalent(SE(r=-0.742,Pr=-0.395, Pr=-0.374, Pr=0.411, Pr=0.099, P=0.060and WWD(r=0.061, P=0.252. There was also a significant correlation between AL and age(P=0.001, SE(PPPCONCLUSION: In longer eyes, there is a tendency toward myopia, a flatter cornea, a deeper ACD and a thinner RNFLT. Age is an influencing factor for the AL as well.

  2. Length scales and selforganization in dense suspension flows

    NARCIS (Netherlands)

    Düring, G.; Lerner, E.; Wyart, M.

    2014-01-01

    Dense non-Brownian suspension flows of hard particles display mystifying properties: As the jamming threshold is approached, the viscosity diverges, as well as a length scale that can be identified from velocity correlations. To unravel the microscopic mechanism governing dissipation and its

  3. Progress in Long Scale Length Laser-Plasma Interactions

    International Nuclear Information System (INIS)

    Glenzer, S H; Arnold, P; Bardsley, G; Berger, R L; Bonanno, G; Borger, T; Bower, D E; Bowers, M; Bryant, R; Buckman, S.; Burkhart, S C; Campbell, K; Chrisp, M P; Cohen, B I; Constantin, G; Cooper, F; Cox, J; Dewald, E; Divol, L; Dixit, S; Duncan, J; Eder, D; Edwards, J; Erbert, G; Felker, B; Fornes, J; Frieders, G; Froula, D H; Gardner, S D; Gates, C; Gonzalez, M; Grace, S; Gregori, G; Greenwood, A; Griffith, R; Hall, T; Hammel, B A; Haynam, C; Heestand, G; Henesian, M; Hermes, G; Hinkel, D; Holder, J; Holdner, F; Holtmeier, G; Hsing, W; Huber, S; James, T; Johnson, S; Jones, O S; Kalantar, D; Kamperschroer, J H; Kauffman, R; Kelleher, T; Knight, J; Kirkwood, R K; Kruer, W L; Labiak, W; Landen, O L; Langdon, A B; Langer, S; Latray, D; Lee, A; Lee, F D; Lund, D; MacGowan, B; Marshall, S; McBride, J; McCarville, T; McGrew, L; Mackinnon, A J; Mahavandi, S; Manes, K; Marshall, C; Mertens, E; Meezan, N; Miller, G; Montelongo, S; Moody, J D; Moses, E; Munro, D; Murray, J; Neumann, J; Newton, M; Ng, E; Niemann, C; Nikitin, A; Opsahl, P; Padilla, E; Parham, T; Parrish, G; Petty, C; Polk, M; Powell, C; Reinbachs, I; Rekow, V; Rinnert, R; Riordan, B; Rhodes, M.

    2003-01-01

    The first experiments on the National Ignition Facility (NIF) have employed the first four beams to measure propagation and laser backscattering losses in large ignition-size plasmas. Gas-filled targets between 2 mm and 7 mm length have been heated from one side by overlapping the focal spots of the four beams from one quad operated at 351 nm (3ω) with a total intensity of 2 x 10 15 W cm -2 . The targets were filled with 1 atm of CO 2 producing of up to 7 mm long homogeneously heated plasmas with densities of n e = 6 x 10 20 cm -3 and temperatures of T e = 2 keV. The high energy in a NIF quad of beams of 16kJ, illuminating the target from one direction, creates unique conditions for the study of laser plasma interactions at scale lengths not previously accessible. The propagation through the large-scale plasma was measured with a gated x-ray imager that was filtered for 3.5 keV x rays. These data indicate that the beams interact with the full length of this ignition-scale plasma during the last ∼1 ns of the experiment. During that time, the full aperture measurements of the stimulated Brillouin scattering and stimulated Raman scattering show scattering into the four focusing lenses of 6% for the smallest length (∼2 mm). increasing to 12% for ∼7 mm. These results demonstrate the NIF experimental capabilities and further provide a benchmark for three-dimensional modeling of the laser-plasma interactions at ignition-size scale lengths

  4. Progress in long scale length laser plasma interactions

    Science.gov (United States)

    Glenzer, S. H.; Arnold, P.; Bardsley, G.; Berger, R. L.; Bonanno, G.; Borger, T.; Bower, D. E.; Bowers, M.; Bryant, R.; Buckman, S.; Burkhart, S. C.; Campbell, K.; Chrisp, M. P.; Cohen, B. I.; Constantin, C.; Cooper, F.; Cox, J.; Dewald, E.; Divol, L.; Dixit, S.; Duncan, J.; Eder, D.; Edwards, J.; Erbert, G.; Felker, B.; Fornes, J.; Frieders, G.; Froula, D. H.; Gardner, S. D.; Gates, C.; Gonzalez, M.; Grace, S.; Gregori, G.; Greenwood, A.; Griffith, R.; Hall, T.; Hammel, B. A.; Haynam, C.; Heestand, G.; Henesian, M.; Hermes, G.; Hinkel, D.; Holder, J.; Holdner, F.; Holtmeier, G.; Hsing, W.; Huber, S.; James, T.; Johnson, S.; Jones, O. S.; Kalantar, D.; Kamperschroer, J. H.; Kauffman, R.; Kelleher, T.; Knight, J.; Kirkwood, R. K.; Kruer, W. L.; Labiak, W.; Landen, O. L.; Langdon, A. B.; Langer, S.; Latray, D.; Lee, A.; Lee, F. D.; Lund, D.; MacGowan, B.; Marshall, S.; McBride, J.; McCarville, T.; McGrew, L.; Mackinnon, A. J.; Mahavandi, S.; Manes, K.; Marshall, C.; Menapace, J.; Mertens, E.; Meezan, N.; Miller, G.; Montelongo, S.; Moody, J. D.; Moses, E.; Munro, D.; Murray, J.; Neumann, J.; Newton, M.; Ng, E.; Niemann, C.; Nikitin, A.; Opsahl, P.; Padilla, E.; Parham, T.; Parrish, G.; Petty, C.; Polk, M.; Powell, C.; Reinbachs, I.; Rekow, V.; Rinnert, R.; Riordan, B.; Rhodes, M.; Roberts, V.; Robey, H.; Ross, G.; Sailors, S.; Saunders, R.; Schmitt, M.; Schneider, M. B.; Shiromizu, S.; Spaeth, M.; Stephens, A.; Still, B.; Suter, L. J.; Tietbohl, G.; Tobin, M.; Tuck, J.; Van Wonterghem, B. M.; Vidal, R.; Voloshin, D.; Wallace, R.; Wegner, P.; Whitman, P.; Williams, E. A.; Williams, K.; Winward, K.; Work, K.; Young, B.; Young, P. E.; Zapata, P.; Bahr, R. E.; Seka, W.; Fernandez, J.; Montgomery, D.; Rose, H.

    2004-12-01

    The first experiments on the National Ignition Facility (NIF) have employed the first four beams to measure propagation and laser backscattering losses in large ignition-size plasmas. Gas-filled targets between 2 and 7 mm length have been heated from one side by overlapping the focal spots of the four beams from one quad operated at 351 nm (3ω) with a total intensity of 2 × 1015 W cm-2. The targets were filled with 1 atm of CO2 producing up to 7 mm long homogeneously heated plasmas with densities of ne = 6 × 1020 cm-3 and temperatures of Te = 2 keV. The high energy in an NIF quad of beams of 16 kJ, illuminating the target from one direction, creates unique conditions for the study of laser-plasma interactions at scale lengths not previously accessible. The propagation through the large-scale plasma was measured with a gated x-ray imager that was filtered for 3.5 keV x-rays. These data indicate that the beams interact with the full length of this ignition-scale plasma during the last ~1 ns of the experiment. During that time, the full aperture measurements of the stimulated Brillouin scattering and stimulated Raman scattering show scattering into the four focusing lenses of 3% for the smallest length (~2 mm), increasing to 10-12% for ~7 mm. These results demonstrate the NIF experimental capabilities and further provide a benchmark for three-dimensional modelling of the laser-plasma interactions at ignition-size scale lengths.

  5. Scattering Length Scaling Laws for Ultracold Three-Body Collisions

    International Nuclear Information System (INIS)

    D'Incao, J.P.; Esry, B.D.

    2005-01-01

    We present a simple and unifying picture that provides the energy and scattering length dependence for all inelastic three-body collision rates in the ultracold regime for three-body systems with short-range two-body interactions. Here, we present the scaling laws for vibrational relaxation, three-body recombination, and collision-induced dissociation for systems that support s-wave two-body collisions. These systems include three identical bosons, two identical bosons, and two identical fermions. Our approach reproduces all previous results, predicts several others, and gives the general form of the scaling laws in all cases

  6. Transition in multiple-scale-lengths turbulence in plasmas

    International Nuclear Information System (INIS)

    Itoh, S.-I.; Yagi, M.; Kawasaki, M.; Kitazawa, A.

    2002-02-01

    The statistical theory of strong turbulence in inhomogeneous plasmas is developed for the cases where fluctuations with different scale-lengths coexist. Statistical nonlinear interactions between semi-micro and micro modes are first kept in the analysis as the drag, noise and drive. The nonlinear dynamics determines both the fluctuation levels and the cross field turbulent transport for the fixed global parameters. A quenching or suppressing effect is induced by their nonlinear interplay, even if both modes are unstable when analyzed independently. Influence of the inhomogeneous global radial electric field is discussed. A new insight is given for the physics of internal transport barrier. The thermal fluctuation of the scale length of λ D is assumed to be statistically independent. The hierarchical structure is constructed according to the scale lengths. Transitions in turbulence are found and phase diagrams with cusp type catastrophe are obtained. Dynamics is followed. Statistical properties of the subcritical excitation are discussed. The probability density function (PDF) and transition probability are obtained. Power-laws are obtained in the PDF as well as in the transition probability. Generalization for the case where turbulence is composed of three-classes of modes is also developed. A new catastrophe of turbulent sates is obtained. (author)

  7. Length scale and manufacturability in density-based topology optimization

    DEFF Research Database (Denmark)

    Lazarov, Boyan Stefanov; Wang, Fengwen; Sigmund, Ole

    2016-01-01

    Since its original introduction in structural design, density-based topology optimization has been applied to a number of other fields such as microelectromechanical systems, photonics, acoustics and fluid mechanics. The methodology has been well accepted in industrial design processes where it can...... performance and in many cases can completely destroy the optimality of the solution. Therefore, the goal of this paper is to review recent advancements in obtaining manufacturable topology-optimized designs. The focus is on methods for imposing minimum and maximum length scales, and ensuring manufacturable...

  8. Multi length-scale characterisation inorganic materials series

    CERN Document Server

    Bruce, Duncan W; Walton, Richard I

    2013-01-01

    Whereas the first five volumes in the Inorganic Materials Series focused on particular classes of materials (synthesis, structures, chemistry, and properties), it is now very timely to provide complementary volumes that introduce and review state-of-the-art techniques for materials characterization. This is an important way of emphasizing the interplay of chemical synthesis and physical characterization. The methods reviewed include spectroscopic, diffraction, and surface techniques that examine the structure of materials on all length scales, from local atomic structure to long-range crystall

  9. Interaction of turbulent length scales with wind turbine blades

    Science.gov (United States)

    Torres-Nieves, Sheilla N.

    Understanding the effects of free-stream turbulence (FST) and surface roughness on the flow around wind turbine blades is imperative in the quest for higher wind turbine efficiency, specially under stall conditions. While many investigations have focused on the aerodynamic loads on wind turbine airfoils, there are no studies that examine the effects of free-stream turbulence and surface roughness on the velocity field around a wind turbine airfoil. Hence, the aim of this investigation is to study the influence of high levels of FST on the flow around smooth and rough surfaces with pressure gradients. Moreover, of great importance in this study is the examination of how the length scales of turbulence and surface roughness interact in the flow over wind turbine airfoils to affect flow separation. Particle Image Velocimetry measurements were performed to analyze the overall flow around a S809 wind turbine blade. Results indicate that when the flow is fully attached, free-stream turbulence significantly decreases aerodynamic efficiency by 82%, yielding to higher loads and fatigue on the blades. On the contrary, when the flow is separated, the effect is reversed and aerodynamic performance is slightly improved (i.e., by 5%) by the presence of the free-stream turbulence. Analysis of the mean flow over the suction surface shows that, under stall conditions, free-stream turbulence delays separation, and surface roughness advances separation. Interestingly, the highly non-linear interaction between free-stream turbulence and surface roughness results in the further advancement of separation. Of particular interest is the study of the region closer to the wall (i.e., the boundary layer), where the flow interacts with both the surface of the blade and the free-stream. Turbulent boundary layer experiments subject to an external favorable pressure gradient (FPG) were performed to study the influence of FST, surface roughness and external pressure gradient (present around the

  10. Cosmogenesis and the origin of the fundamental length scale

    CERN Document Server

    Brout, R; Frère, J M; Gunzig, E; Nardone, P; Truffin, C; Spindel, P

    1980-01-01

    The creation of the universe is regarded as a self-consistent process in which matter is engendered by the space-time varying cosmological gravitational field and vice versa. Abundant production can occur only if the mass of the particles so created is of the order of the Planck mass $(=K^{-1/2})$. We conjecture that this is the origin of the fundamental length scale in field theory, as it is encountered, for example, in present efforts towards grandunification. The region of particle production is steady state in character. It ceases when the produced particles decay. The geometry of this steady state is characteristic of a de Sitter space. It permits one to estimate the number of ordinary particles presently observed, N. We find log N = O (mτ$_{decay}$) = O(g$^{−2}$) = O(10$^2$), with the usual estimate of g = O(10$^{−1}$) at the Planck length scale. This is not inconsistent with the experimental estimate $N \\approx O(10^{90})$. After production, cosmological history gives way to the more conventional ...

  11. Dynamic Leidenfrost Effect: Relevant Time and Length Scales

    Science.gov (United States)

    Shirota, Minori; van Limbeek, Michiel A. J.; Sun, Chao; Prosperetti, Andrea; Lohse, Detlef

    2016-02-01

    When a liquid droplet impacts a hot solid surface, enough vapor may be generated under it to prevent its contact with the solid. The minimum solid temperature for this so-called Leidenfrost effect to occur is termed the Leidenfrost temperature, or the dynamic Leidenfrost temperature when the droplet velocity is non-negligible. We observe the wetting or drying and the levitation dynamics of the droplet impacting on an (isothermal) smooth sapphire surface using high-speed total internal reflection imaging, which enables us to observe the droplet base up to about 100 nm above the substrate surface. By this method we are able to reveal the processes responsible for the transitional regime between the fully wetting and the fully levitated droplet as the solid temperature increases, thus shedding light on the characteristic time and length scales setting the dynamic Leidenfrost temperature for droplet impact on an isothermal substrate.

  12. Density Functional Theory and Materials Modeling at Atomistic Length Scales

    Directory of Open Access Journals (Sweden)

    Swapan K. Ghosh

    2002-04-01

    Full Text Available Abstract: We discuss the basic concepts of density functional theory (DFT as applied to materials modeling in the microscopic, mesoscopic and macroscopic length scales. The picture that emerges is that of a single unified framework for the study of both quantum and classical systems. While for quantum DFT, the central equation is a one-particle Schrodinger-like Kohn-Sham equation, the classical DFT consists of Boltzmann type distributions, both corresponding to a system of noninteracting particles in the field of a density-dependent effective potential, the exact functional form of which is unknown. One therefore approximates the exchange-correlation potential for quantum systems and the excess free energy density functional or the direct correlation functions for classical systems. Illustrative applications of quantum DFT to microscopic modeling of molecular interaction and that of classical DFT to a mesoscopic modeling of soft condensed matter systems are highlighted.

  13. Relative gut lengths of coral reef butterflyfishes (Pisces: Chaetodontidae)

    KAUST Repository

    Berumen, Michael L.

    2011-06-17

    Variation in gut length of closely related animals is known to generally be a good predictor of dietary habits. We examined gut length in 28 species of butterflyfishes (Chaetodontidae), which encompass a wide range of dietary types (planktivores, omnivores, and corallivores). We found general dietary patterns to be a good predictor of relative gut length, although we found high variation among groups and covariance with body size. The longest gut lengths are found in species that exclusively feed on the living tissue of corals, while the shortest gut length is found in a planktivorous species. Although we tried to control for phylogeny, corallivory has arisen multiple times in this family, confounding our analyses. The butterflyfishes, a speciose family with a wide range of dietary habits, may nonetheless provide an ideal system for future work studying gut physiology associated with specialization and foraging behaviors. © 2011 Springer-Verlag.

  14. Length Scale of Leidenfrost Ratchet Switches Droplet Directionality

    Energy Technology Data Exchange (ETDEWEB)

    Agapov, Rebecca L [ORNL; Boreyko, Jonathan B [ORNL; Briggs, Dayrl P [ORNL; Srijanto, Bernadeta R [ORNL; Retterer, Scott T [ORNL; Collier, Pat [ORNL; Lavrik, Nickolay V [ORNL

    2014-01-01

    Arrays of tilted pillars with characteristic heights spanning from hundreds of nanometers to tens of micrometers were created using wafer level processing and used as Leidenfrost ratchets to control droplet directionality. Dynamic Leidenfrost droplets on the ratchets with nanoscale features were found to move in the direction of the pillar tilt while the opposite directionality was observed on the microscale ratchets. This remarkable switch in the droplet directionality can be explained by varying contributions from the two distinct mechanisms controlling droplet motion on Leidenfrost ratchets with nanoscale and microscale features. In particular, asymmetric wettability of dynamic Leidenfrost droplets upon initial impact appears to be the dominant mechanism determining their directionality on tilted nanoscale pillar arrays. By contrast, asymmetric wetting does not provide a strong enough driving force compared to the forces induced by asymmetric vapour flow on arrays of much taller tilted microscale pillars. Furthermore, asymmetric wetting plays a role only in the dynamic Leidenfrost regime, for instance when droplets repeatedly jump after their initial impact. The point of crossover between the two mechanisms coincides with the pillar heights comparable to the values of the thinnest vapor layers still capable of cushioning Leidenfrost droplets upon their initial impact. The proposed model of the length scale dependent interplay between the two mechanisms points to the previously unexplored ability to bias movement of dynamic Leidenfrost droplets and even switch their directionality.

  15. Length scale of Leidenfrost ratchet switches droplet directionality.

    Science.gov (United States)

    Agapov, Rebecca L; Boreyko, Jonathan B; Briggs, Dayrl P; Srijanto, Bernadeta R; Retterer, Scott T; Collier, C Patrick; Lavrik, Nickolay V

    2014-08-07

    Arrays of tilted pillars with characteristic heights spanning from hundreds of nanometers to tens of micrometers were created using wafer level processing and used as Leidenfrost ratchets to control droplet directionality. Dynamic Leidenfrost droplets on the ratchets with nanoscale features were found to move in the direction of the pillar tilt while the opposite directionality was observed on the microscale ratchets. This remarkable switch in the droplet directionality can be explained by varying contributions from the two distinct mechanisms controlling droplet motion on Leidenfrost ratchets with nanoscale and microscale features. In particular, asymmetric wettability of dynamic Leidenfrost droplets upon initial impact appears to be the dominant mechanism determining their directionality on tilted nanoscale pillar arrays. By contrast, asymmetric wetting does not provide a strong enough driving force compared to the forces induced by asymmetric vapour flow on arrays of much taller tilted microscale pillars. Furthermore, asymmetric wetting plays a role only in the dynamic Leidenfrost regime, for instance when droplets repeatedly jump after their initial impact. The point of crossover between the two mechanisms coincides with the pillar heights comparable to the values of the thinnest vapor layers still capable of cushioning Leidenfrost droplets upon their initial impact. The proposed model of the length scale dependent interplay between the two mechanisms points to the previously unexplored ability to bias movement of dynamic Leidenfrost droplets and even switch their directionality.

  16. A New Universal Gas Breakdown Theory for Classical Length Scales

    Science.gov (United States)

    Loveless, Amanda Mae

    While Paschen's law is commonly used to predict breakdown voltage, it fails at microscale gaps when field emission becomes important. Accurate breakdown voltage predictions at microscale are even more important as electronic device dimensions decrease. Developing analytic models to accurately predict breakdown at microscale is vital for understanding the underlying physics occurring within the system and to either prevent or produce a discharge, depending on the application. We first take a pre-existing breakdown model coupling field emission and Townsend breakdown and perform a matched asymptotic analysis to obtain analytic equations for breakdown voltage in argon at atmospheric pressure. Next, we extend this model to generalize for gas and further explore the independent contributions of field emission and Townsend discharge. Finally, we present analytic expressions for breakdown voltage valid for any gas at any pressure, and discuss the modified Paschen minimum at microscale. The presented models agree well with numerical simulations and experimental data when using the field enhancement factor as a fitting parameter. The work presented in this thesis is a first step in unifying gas breakdown across length scales and breakdown mechanisms. Future work will aim to incorporate other breakdown mechanisms, such as quantum effects and space charge, to provide a more complete unified model for gas breakdown.

  17. Optimal renormalization scales and commensurate scale relations

    International Nuclear Information System (INIS)

    Brodsky, S.J.; Lu, H.J.

    1996-01-01

    Commensurate scale relations relate observables to observables and thus are independent of theoretical conventions, such as the choice of intermediate renormalization scheme. The physical quantities are related at commensurate scales which satisfy a transitivity rule which ensures that predictions are independent of the choice of an intermediate renormalization scheme. QCD can thus be tested in a new and precise way by checking that the observables track both in their relative normalization and in their commensurate scale dependence. For example, the radiative corrections to the Bjorken sum rule at a given momentum transfer Q can be predicted from measurements of the e+e - annihilation cross section at a corresponding commensurate energy scale √s ∝ Q, thus generalizing Crewther's relation to non-conformal QCD. The coefficients that appear in this perturbative expansion take the form of a simple geometric series and thus have no renormalon divergent behavior. The authors also discuss scale-fixed relations between the threshold corrections to the heavy quark production cross section in e+e - annihilation and the heavy quark coupling α V which is measurable in lattice gauge theory

  18. Scale and time dependence of serial correlations in word-length time series of written texts

    Science.gov (United States)

    Rodriguez, E.; Aguilar-Cornejo, M.; Femat, R.; Alvarez-Ramirez, J.

    2014-11-01

    This work considered the quantitative analysis of large written texts. To this end, the text was converted into a time series by taking the sequence of word lengths. The detrended fluctuation analysis (DFA) was used for characterizing long-range serial correlations of the time series. To this end, the DFA was implemented within a rolling window framework for estimating the variations of correlations, quantified in terms of the scaling exponent, strength along the text. Also, a filtering derivative was used to compute the dependence of the scaling exponent relative to the scale. The analysis was applied to three famous English-written literary narrations; namely, Alice in Wonderland (by Lewis Carrol), Dracula (by Bram Stoker) and Sense and Sensibility (by Jane Austen). The results showed that high correlations appear for scales of about 50-200 words, suggesting that at these scales the text contains the stronger coherence. The scaling exponent was not constant along the text, showing important variations with apparent cyclical behavior. An interesting coincidence between the scaling exponent variations and changes in narrative units (e.g., chapters) was found. This suggests that the scaling exponent obtained from the DFA is able to detect changes in narration structure as expressed by the usage of words of different lengths.

  19. Chirality transfer across length-scales in nematic liquid crystals: fundamentals and applications.

    Science.gov (United States)

    Pieraccini, Silvia; Masiero, Stefano; Ferrarini, Alberta; Piero Spada, Gian

    2011-01-01

    When a chiral dopant is dissolved in an achiral liquid crystal medium, the whole sample organizes into a helical structure with a characteristic length-scale of the order of microns. The relation between chirality at these quite different length-scales can be rationalized by a relatively simple model, which retains the relevant factors coming into play: the molecular shape of the chiral dopant, which controls the chirality of short range intermolecular interactions, and the elastic properties of the nematic environment, which control the restoring torques opposing distortion of the director. In this tutorial review the relation between molecular and phase chirality will be reviewed and several applications of the chiral doping of nematic LCs will be discussed. These range from the exploitation of the amplified molecular chirality for stereochemical purposes (e.g., the determination of the absolute configuration or the enantiomeric excess), to newer applications in physico-chemical fields. The latter take advantage of the periodicity of the chiral field, with length-scales ranging from hundreds to thousands of nanometres, which characterise the cholesteric phase.

  20. Characterizing the Surface Roughness Length Scales of Lactose Carrier Particles in Dry Powder Inhalers.

    Science.gov (United States)

    Tan, Bernice Mei Jin; Chan, Lai Wah; Heng, Paul Wan Sia

    2018-03-06

    Surface roughness is well recognized as a critical physical property of particulate systems, particularly in relation to adhesion, friction, and flow. An example is the surface property of carrier particles in carrier-based dry powder inhaler (DPI) formulations. The numerical characterization of roughness remains rather unsatisfactory due to the lack of spatial (or length scale) information about surface features when a common amplitude parameter such as average roughness ( R a ) is used. An analysis of the roughness of lactose carrier particles at three different length scales, designed for specificity to the study of interactive mixtures in DPI, was explored in this study. Three R a parameters were used to represent the microscale, intermediate scale, and macroscale roughness of six types of surface-modified carriers. Coating of micronized lactose fines on coarse carrier particles increased their microroughness from 389 to 639 nm while the macroroughness was not affected. Roller compaction at higher roll forces led to very effective surface roughening, particularly at longer length scales. Changes in R a parameters corroborated the visual observations of particles under the scanning electron microscope. Roughness at the intermediate scale showed the best correlation with the fine particle fraction (FPF) of DPI formulations. From the range of 250 to 650 nm, every 100 nm increase in the intermediate roughness led to ∼8% increase in the FPF. However, the effect of surface roughness was greatly diminished when fine lactose (median size, 9 μm) of comparable amounts to the micronized drug were added to the formulation. The combination of roughness parameters at various length scales provided much discriminatory surface information, which then revealed the "quality" of roughness necessary for improving DPI performance.

  1. Optimization of inhibitory decision rules relative to length and coverage

    KAUST Repository

    Alsolami, Fawaz

    2012-01-01

    The paper is devoted to the study of algorithms for optimization of inhibitory rules relative to the length and coverage. In contrast with usual rules that have on the right-hand side a relation "attribute ≠ value", inhibitory rules have a relation "attribute = value" on the right-hand side. The considered algorithms are based on extensions of dynamic programming. © 2012 Springer-Verlag.

  2. Length scales for the Navier-Stokes equations on a rotating sphere

    International Nuclear Information System (INIS)

    Kyrychko, Yuliya N.; Bartuccelli, Michele V.

    2004-01-01

    In this Letter we obtain the dissipative length scale for the Navier-Stokes equations on a two-dimensional rotating sphere S 2 . This system is a fundamental model of the large scale atmospheric dynamics. Using the equations of motion in their vorticity form, we construct the ladder inequalities from which a set of time-averaged length scales is obtained

  3. Determination of length scale effects in nonlocal media

    NARCIS (Netherlands)

    Simone, A; Iacono, C; Sluys, LJ; Yao, ZH; Yuan, MW; Zhong, WX

    2004-01-01

    A combined continuous-discontinuous framework for failure is presented. Continuous failure is described with a gradient enhanced damage model and discontinuous failure is introduced by adding discontinuities to finite elements through a node-based enhancement. The continuous model contains a length

  4. On the length-scale of the wind profile

    DEFF Research Database (Denmark)

    Pena Diaz, Alfredo; Gryning, Sven-Erik; Mann, Jakob

    2010-01-01

    We present the results of an analysis of simultaneous sonic anemometer observations of wind speed and velocity spectra over flat and homogeneous terrain from 10 up to 160 m height performed at the National Test Station for Wind Turbines at Høvsøre, Denmark. The mixing length, l, derived from the ...

  5. Internal Length Gradient (ILG) Material Mechanics Across Scales & Disciplines

    OpenAIRE

    Aifantis, Elias C.

    2016-01-01

    A combined theoretical/numerical/experimental program is outlined for extending the ILG approach to consider time lags, stochasticity and multiphysics couplings. Through this extension it is possible to discuss the interplay between deformation internal lengths (ILs) and ILs induced by thermal, diffusion or electric field gradients. Size-dependent multiphysics stability diagrams are obtained, and size-dependent serrated stress-strain curves are interpreted through combined gradient-stochastic...

  6. Non-perturbative gravity at different length scales

    International Nuclear Information System (INIS)

    Folkerts, Sarah

    2013-01-01

    In this thesis, we investigate different aspects of gravity as an effective field theory. Building on the arguments of self-completeness of Einstein gravity, we argue that any sensible theory, which does not propagate negative-norm states and reduces to General Relativity in the low energy limit is self-complete. Due to black hole formation in high energy scattering experiments, distances smaller than the Planck scale are shielded from any accessibility. Degrees of freedom with masses larger than the Planck mass are mapped to large classical black holes which are described by the already existing infrared theory. Since high energy (UV) modifications of gravity which are ghost-free can only produce stronger gravitational interactions than Einstein gravity, the black hole shielding is even more efficient in such theories. In this light, we argue that conventional attempts of a Wilsonian UV completion are severely constrained. Furthermore, we investigate the quantum picture for black holes which emerges in the low energy description put forward by Dvali and Gomez in which black holes are described as Bose-Einstein condensates of many weakly coupled gravitons. Specifically, we investigate a non-relativistic toy model which mimics certain aspects of the graviton condensate picture. This toy model describes the collapse of a condensate of attractive bosons which emits particles due to incoherent scattering. We show that it is possible that the evolution of the condensate follows the critical point which is accompanied by the appearance of a light mode. Another aspect of gravitational interactions concerns the question whether quantum gravity breaks global symmetries. Arguments relying on the no hair theorem and wormhole solutions suggest that global symmetries can be violated. In this thesis, we parametrize such effects in terms of an effective field theory description of three-form fields. We investigate the possible implications for the axion solution of the strong CP

  7. Non-perturbative gravity at different length scales

    Energy Technology Data Exchange (ETDEWEB)

    Folkerts, Sarah

    2013-12-18

    In this thesis, we investigate different aspects of gravity as an effective field theory. Building on the arguments of self-completeness of Einstein gravity, we argue that any sensible theory, which does not propagate negative-norm states and reduces to General Relativity in the low energy limit is self-complete. Due to black hole formation in high energy scattering experiments, distances smaller than the Planck scale are shielded from any accessibility. Degrees of freedom with masses larger than the Planck mass are mapped to large classical black holes which are described by the already existing infrared theory. Since high energy (UV) modifications of gravity which are ghost-free can only produce stronger gravitational interactions than Einstein gravity, the black hole shielding is even more efficient in such theories. In this light, we argue that conventional attempts of a Wilsonian UV completion are severely constrained. Furthermore, we investigate the quantum picture for black holes which emerges in the low energy description put forward by Dvali and Gomez in which black holes are described as Bose-Einstein condensates of many weakly coupled gravitons. Specifically, we investigate a non-relativistic toy model which mimics certain aspects of the graviton condensate picture. This toy model describes the collapse of a condensate of attractive bosons which emits particles due to incoherent scattering. We show that it is possible that the evolution of the condensate follows the critical point which is accompanied by the appearance of a light mode. Another aspect of gravitational interactions concerns the question whether quantum gravity breaks global symmetries. Arguments relying on the no hair theorem and wormhole solutions suggest that global symmetries can be violated. In this thesis, we parametrize such effects in terms of an effective field theory description of three-form fields. We investigate the possible implications for the axion solution of the strong CP

  8. SQUID magnetometry from nanometer to centimeter length scales

    International Nuclear Information System (INIS)

    Hatridge, Michael J.

    2010-01-01

    The development of Superconducting QUantum Interference Device (SQUID)-based magnetometer for two applications, in vivo prepolarized, ultra-low field MRI of humans and dispersive readout of SQUIDs for micro- and nano-scale magnetometery, are the focus of this thesis.

  9. SQUID magnetometry from nanometer to centimeter length scales

    Energy Technology Data Exchange (ETDEWEB)

    Hatridge, Michael J. [Univ. of California, Berkeley, CA (United States)

    2010-06-01

    The development of Superconducting QUantum Interference Device (SQUID)-based magnetometer for two applications, in vivo prepolarized, ultra-low field MRI of humans and dispersive readout of SQUIDs for micro- and nano-scale magnetometery, are the focus of this thesis.

  10. Length and time scales of atmospheric moisture recycling

    NARCIS (Netherlands)

    Van der Ent, R.J.; Savenije, H.H.G.

    2011-01-01

    It is difficult to quantify the degree to which terrestrial evaporation supports the occurrence of precipitation within a certain study region (i.e. regional moisture recycling) due to the scale- and shape-dependence of regional moisture recycling ratios. In this paper we present a novel approach to

  11. Determination of Longitudinal Electron Bunch Lengths on Picosecond Time Scales

    CERN Document Server

    Martínez, C; Calviño, F

    1999-01-01

    At CERN (European Laboratory for Particle Physics) the CLIC (Compact Linear Collider) study is pursuing the design of an electron-positron high-energy linear collider using an innovative concept for the RF (Radio Frequency) power production, the socalled two-beam acceleration scheme. In order to keep the length of the collider in a reasonable range while being able of accelerating electrons and positrons up to 5 TeV, the normal-conducting accelerating structures should operate at very high frequency (in this case 30 GHz). The RF power necessary to feed the accelerating cavities is provided by a second electron beam, the drive beam, running parallel to the main beam. The CLIC Test Facility (CTF) was build with the main aim of studying and demonstrating the feasibility of the two beam acceleration scheme and technology. It is composed of two beams, the drive beam that will generate the 30 GHz RF power and the main beam which will be accelerated by this power. In order to have a good efficiency for the power gen...

  12. Displacement-length scaling of brittle faults in ductile shear.

    Science.gov (United States)

    Grasemann, Bernhard; Exner, Ulrike; Tschegg, Cornelius

    2011-11-01

    Within a low-grade ductile shear zone, we investigated exceptionally well exposed brittle faults, which accumulated antithetic slip and rotated into the shearing direction. The foliation planes of the mylonitic host rock intersect the faults approximately at their centre and exhibit ductile reverse drag. Three types of brittle faults can be distinguished: (i) Faults developing on pre-existing K-feldspar/mica veins that are oblique to the shear direction. These faults have triclinic flanking structures. (ii) Wing cracks opening as mode I fractures at the tips of the triclinic flanking structures, perpendicular to the shear direction. These cracks are reactivated as faults with antithetic shear, extend from the parent K-feldspar/mica veins and form a complex linked flanking structure system. (iii) Joints forming perpendicular to the shearing direction are deformed to form monoclinic flanking structures. Triclinic and monoclinic flanking structures record elliptical displacement-distance profiles with steep displacement gradients at the fault tips by ductile flow in the host rocks, resulting in reverse drag of the foliation planes. These structures record one of the greatest maximum displacement/length ratios reported from natural fault structures. These exceptionally high ratios can be explained by localized antithetic displacement along brittle slip surfaces, which did not propagate during their rotation during surrounding ductile flow.

  13. Displacement–length scaling of brittle faults in ductile shear

    Science.gov (United States)

    Grasemann, Bernhard; Exner, Ulrike; Tschegg, Cornelius

    2011-01-01

    Within a low-grade ductile shear zone, we investigated exceptionally well exposed brittle faults, which accumulated antithetic slip and rotated into the shearing direction. The foliation planes of the mylonitic host rock intersect the faults approximately at their centre and exhibit ductile reverse drag. Three types of brittle faults can be distinguished: (i) Faults developing on pre-existing K-feldspar/mica veins that are oblique to the shear direction. These faults have triclinic flanking structures. (ii) Wing cracks opening as mode I fractures at the tips of the triclinic flanking structures, perpendicular to the shear direction. These cracks are reactivated as faults with antithetic shear, extend from the parent K-feldspar/mica veins and form a complex linked flanking structure system. (iii) Joints forming perpendicular to the shearing direction are deformed to form monoclinic flanking structures. Triclinic and monoclinic flanking structures record elliptical displacement–distance profiles with steep displacement gradients at the fault tips by ductile flow in the host rocks, resulting in reverse drag of the foliation planes. These structures record one of the greatest maximum displacement/length ratios reported from natural fault structures. These exceptionally high ratios can be explained by localized antithetic displacement along brittle slip surfaces, which did not propagate during their rotation during surrounding ductile flow. PMID:26806996

  14. Morphology Characterization of PP/Clay Nanocomposites Across the Length Scales of the Structural Architecture

    NARCIS (Netherlands)

    Szazdi, Laszlo; Abranyi, Agnes; Pukansky Jr, Bela; Vancso, Gyula J.; Pukanszky, B.; Pukanszky, Bela

    2006-01-01

    The structure and rheological properties of a large number of layered silicate poly(propylene) nanocomposites were studied with widely varying compositions. Morphology characterization at different length scales was achieved by SEM, TEM, and XRD. Rheological measurements supplied additional

  15. In Situ Observation of Strain Evolution in Cp-Ti Over Multiple Length Scales

    Science.gov (United States)

    Bettles, C. J.; Lynch, P. A.; Stevenson, A. W.; Tomus, D.; Gibson, M. A.; Wallwork, K.; Kimpton, J.

    2011-01-01

    The strain evolution in polycrystalline CP-Ti strip under tension was studied in situ and at two length scales using Synchrotron X-ray diffraction. To establish the bulk material behavior, experiments were performed at the Australian Synchrotron facility. Because of the relatively large grain size, discontinuous "spotty" Debye ring patterns were observed, and a peak fitting algorithm was developed to determine the individual spot positions with the necessary precision for strain determination. The crystallographic directional dependence of strain anisotropy during the loading cycle was determined. Strain anisotropy and yielding of individual crystallographic planes prior to the macroscopic yield point were further clarified by in situ loading experiments performed at the Advanced Light Source (ALS). The deviatoric strain accumulation and plastic response were mapped on a grain-by-grain basis. The onset of microscopic yielding in the grains was identified and correlated with the relative orientation of the grains with respect to the loading direction.

  16. Relation between Tolman length and isothermal compressibility for simple liquids

    International Nuclear Information System (INIS)

    Wang Xiao-Song; Zhu Ru-Zeng

    2013-01-01

    The Tolman length δ 0 of a liquid with a plane surface has attracted increasing theoretical attention in recent years, but the expression of Tolman length in terms of observable quantities is still not very clear. In 2001, Bartell gave a simple expression of Tolman length δ 0 in terms of isothermal compressibility. However, this expression predicts that Tolman length is always negative, which is contrary to the results of molecular dynamics simulations (MDS) for simple liquids. In this paper, this contradiction is analyzed and the reason for the discrepancy in the sign is found. In addition, we introduce a new expression of Tolman length in terms of isothermal compressibility for simple fluids not near the critical points under some weak restrictions. The Tolman length of simple liquids calculated by using this formula is consistent with that obtained using MDS regarding the sign

  17. Flame Treatment of Low-Density Polyethylene: Surface Chemistry Across the Length Scale

    NARCIS (Netherlands)

    Song, Jing; Gunst, Ullrich; Arlinghaus, Heinrich F.; Vancso, Gyula J.

    2007-01-01

    The relationship between surface chemistry and morphology of flame treated low-density polyethylene (LDPE) was studied by various characterization techniques across different length scales. The chemical composition of the surface was determined on the micrometer scale by X-ray photoelectron

  18. The PVC technique a method to estimate the dissipation length scale in turbulent flows

    Science.gov (United States)

    Ho, Chih-Ming; Zohar, Yitshak

    1997-12-01

    A time-averaged length scale can be defined by a pair of successive turbulent-velocity derivatives, i.e. [dnu(x)/ dxn][prime prime or minute]/ [dn+1u(x)/ dxn+1][prime prime or minute]. The length scale associated with the zeroth- and the first-order derivatives, u[prime prime or minute]/u[prime prime or minute]x, is the Taylor microscale. In isotropic turbulence, this scale is the average length between zero crossings of the velocity signal. The average length between zero crossings of the first velocity derivative, i.e. u[prime prime or minute]x/u[prime prime or minute]xx, can be reliably obtained by using the peak-valley-counting (PVC) technique. We have found that the most probable scale, rather than the average, equals the wavelength at the peak of the dissipation spectrum in a plane mixing layer (Zohar & Ho 1996). In this study, we experimentally investigate the generality of applying the PVC technique to estimate the dissipation scale in three basic turbulent shear flows: a flat-plate boundary layer, a wake behind a two-dimensional cylinder and a plane mixing layer. We also analytically explore the quantitative relationships among this length scale and the Kolmogorov and Taylor microscales.

  19. Length- weight relationships, condition factor (K) and relative ...

    African Journals Online (AJOL)

    Length-weight relationship and condition factors were estimated for Dentex congoensis and Dentex angolensis of the family sparidae trawled from Nigeria Coastal water in 2009. A total number of 534 specimens ranging from 7.2 – 3.0 cm in total length and 5.4 – 489.8 g in weight were analyzed. The lengthweight ...

  20. Length-weight relationships, condition factors and relative weight of ...

    African Journals Online (AJOL)

    The aim of this study was to record the length-weight relationship parameters and condition factors for some commercially important fish of Bushehr coastal waters of Persian Gulf. The length-weight relationships were calculated for five species caught during fishing surveys using different types of fishing gears (trawls, pots ...

  1. Advancing the speed, sensitivity and accuracy of biomolecular detection using multi-length-scale engineering

    Science.gov (United States)

    Kelley, Shana O.; Mirkin, Chad A.; Walt, David R.; Ismagilov, Rustem F.; Toner, Mehmet; Sargent, Edward H.

    2014-12-01

    Rapid progress in identifying disease biomarkers has increased the importance of creating high-performance detection technologies. Over the last decade, the design of many detection platforms has focused on either the nano or micro length scale. Here, we review recent strategies that combine nano- and microscale materials and devices to produce large improvements in detection sensitivity, speed and accuracy, allowing previously undetectable biomarkers to be identified in clinical samples. Microsensors that incorporate nanoscale features can now rapidly detect disease-related nucleic acids expressed in patient samples. New microdevices that separate large clinical samples into nanocompartments allow precise quantitation of analytes, and microfluidic systems that utilize nanoscale binding events can detect rare cancer cells in the bloodstream more accurately than before. These advances will lead to faster and more reliable clinical diagnostic devices.

  2. Hierarchical self-assembly of two-length-scale multiblock copolymers

    International Nuclear Information System (INIS)

    Brinke, Gerrit ten; Loos, Katja; Vukovic, Ivana; Du Sart, Gerrit Gobius

    2011-01-01

    The self-assembly in diblock copolymer-based supramolecules, obtained by hydrogen bonding short side chains to one of the blocks, as well as in two-length-scale linear terpolymers results in hierarchical structure formation. The orientation of the different domains, e.g. layers in the case of a lamellar-in-lamellar structure, is determined by the molecular architecture, graft-like versus linear, and the relative magnitude of the interactions involved. In both cases parallel and perpendicular arrangements have been observed. The comb-shaped supramolecules approach is ideally suited for the preparation of nanoporous structures. A bicontinuous morphology with the supramolecular comb block forming the channels was finally achieved by extending the original approach to suitable triblock copolymer-based supramolecules.

  3. Scaling of localization length of a quasi 1D system with longitudinal boundary roughness

    International Nuclear Information System (INIS)

    Abhijit Kar Gupta; Sen, A.K.

    1994-08-01

    We introduce irregularities on one of the longitudinal boundaries of a quasi 1D strip which has no bulk disorder. We calculate the localization length of such a system within the scope of tight-binding formalism and see how it behaves with the roughness introduced on the boundary and with the strip-width. We find that localization length scales with a composite one parameter. (author). 6 refs, 4 figs

  4. Microstructural characterization of transformable Fe-Mn alloys at different length scales

    International Nuclear Information System (INIS)

    Liang, X.; Wang, X.; Zurob, H.S.

    2009-01-01

    The as-annealed and deformed Microstructure of transformable Fe-Mn alloys were, comprehensively, characterized over a wide range of length scales. Differential interference contrast optical metallography, combined with a tinting etching method, was employed to examine the grain morphology. A new specimen preparation method, involving electro-polishing and electro-etching, was developed for scanning electron microscopy and electron back-scattered diffraction analysis. This method leads to a very good imaging contrast and thus bridges the length scale gap between optical metallography and transmission electron microscopy. Moreover, it enables simultaneous scanning electron microscopy and electron backscatter diffraction analysis which allows correlations among morphology, crystal orientation and phase analysis in the length scale of microns. Transmission electron microscopy investigations were also made to evaluate the thermal and mechanical transformation products as well as defect structures.

  5. Analytic determination of dynamical and mosaic length scales in a Kac glass model

    Energy Technology Data Exchange (ETDEWEB)

    Franz, S [Abdus Salam ICTP, Strada Costiera 11, PO Box 586, I-34100 Trieste (Italy); Montanari, A [Isaac Newton Institute for Mathematical Sciences 20 Clarkson Road, Cambridge, CB3 0EH (United Kingdom)

    2007-03-16

    We consider a disordered spin model with multi-spin interactions undergoing a glass transition. We introduce dynamic and static length scales and compute them in the Kac limit (long-but-finite range interactions). They diverge at the dynamic and static phase transition with exponents -1/4 and -1 (respectively). The two length scales are approximately equal well above the mode coupling transition. Their discrepancy increases rapidly as this transition is approached. We argue that this signals a crossover from mode coupling to activated dynamics. (fast track communication)

  6. Natural Length Scales of Ecological Systems: Applications at Community and Ecosystem Levels

    Directory of Open Access Journals (Sweden)

    Craig R. Johnson

    2009-06-01

    Full Text Available The characteristic, or natural, length scales of a spatially dynamic ecological landscape are the spatial scales at which the deterministic trends in the dynamic are most sharply in focus. Given recent development of techniques to determine the characteristic length scales (CLSs of real ecological systems, I explore the potential for using CLSs to address three important and vexing issues in applied ecology, viz. (i determining the optimum scales to monitor ecological systems, (ii interpreting change in ecological communities, and (iii ascertaining connectivity between species in complex ecologies. In summarizing the concept of characteristic length scales as system-level scaling thresholds, I emphasize that the primary CLS is, by definition, the optimum scale at which to monitor a system if the objective is to observe its deterministic dynamics at a system level. Using several different spatially explicit individual-based models, I then explore predictions of the underlying theory of CLSs in the context of interpreting change and ascertaining connectivity among species in ecological systems. Analysis of these models support predictions that systems with strongly fluctuating community structure, but an otherwise stable long-term dynamic defined by a stationary attractor, indicate an invariant length scale irrespective of community structure at the time of analysis, and irrespective of the species analyzed. In contrast, if changes in the underlying dynamic are forcibly induced, the shift in dynamics is reflected by a change in the primary length scale. Thus, consideration of the magnitude of the CLS through time enables distinguishing between circumstances where there are temporal changes in community structure but not in the long-term dynamic, from that where changes in community structure reflect some kind of fundamental shift in dynamics. In this context, CLSs emerge as a diagnostic tool to identify phase shifts to alternative stable states

  7. Electropolishing effect on roughness metrics of ground stainless steel: a length scale study

    Science.gov (United States)

    Nakar, Doron; Harel, David; Hirsch, Baruch

    2018-03-01

    Electropolishing is a widely-used electrochemical surface finishing process for metals. The electropolishing of stainless steel has vast commercial application, such as improving corrosion resistance, improving cleanness, and brightening. The surface topography characterization is performed using several techniques with different lateral resolutions and length scales, from atomic force microscopy in the nano-scale (process in the micro and meso lateral scales. Both stylus and optical profilometers are used, and multiple cut-off lengths of the standard Gaussian filter are adopted. While the commonly used roughness amplitude parameters (Ra, Rq and Rz) fail to characterize electropolished textures, the root mean square slope (RΔq) is found to better describe the electropolished surfaces and to be insensitive to scale.

  8. Cervical length at 23 weeks' gestation - relation to demographic ...

    African Journals Online (AJOL)

    Multiple linear regression analysis was used to determine the variables that made a significant independent contribution towards explaining variance in cervical length. Maternal age and BMI were used as continuous variables. Results. During the study period 2 173 patients attending ultrasound clinics for a routine 23-week ...

  9. Nano-scaled graphene platelets with a high length-to-width aspect ratio

    Science.gov (United States)

    Zhamu, Aruna; Guo, Jiusheng; Jang, Bor Z.

    2010-09-07

    This invention provides a nano-scaled graphene platelet (NGP) having a thickness no greater than 100 nm and a length-to-width ratio no less than 3 (preferably greater than 10). The NGP with a high length-to-width ratio can be prepared by using a method comprising (a) intercalating a carbon fiber or graphite fiber with an intercalate to form an intercalated fiber; (b) exfoliating the intercalated fiber to obtain an exfoliated fiber comprising graphene sheets or flakes; and (c) separating the graphene sheets or flakes to obtain nano-scaled graphene platelets. The invention also provides a nanocomposite material comprising an NGP with a high length-to-width ratio. Such a nanocomposite can become electrically conductive with a small weight fraction of NGPs. Conductive composites are particularly useful for shielding of sensitive electronic equipment against electromagnetic interference (EMI) or radio frequency interference (RFI), and for electrostatic charge dissipation.

  10. Length-scale dependent ensemble-averaged conductance of a 1D disordered conductor: Conductance minimum

    International Nuclear Information System (INIS)

    Tit, N.; Kumar, N.; Pradhan, P.

    1993-07-01

    Exact numerical calculation of ensemble averaged length-scale dependent conductance for the 1D Anderson model is shown to support an earlier conjecture for a conductance minimum. Numerical results can be understood in terms of the Thouless expression for the conductance and the Wigner level-spacing statistics. (author). 8 refs, 2 figs

  11. Wind direction variations in the natural wind – A new length scale

    DEFF Research Database (Denmark)

    Johansson, Jens; Christensen, Silas Sverre

    2018-01-01

    During an observation period of e.g. 10min, the wind direction will differ from its mean direction for short periods of time, and a body of air will pass by from that direction before the direction changes once again. The present paper introduces a new length scale which we have labeled the angul...

  12. Channel length scaling and the impact of metal gate work function ...

    Indian Academy of Sciences (India)

    Channel length decreases and becomes crucial in deep-submicrometre technologies. In this work, we study the effect of short channel and the influences of quantum mechanical on nanoscale DG-MOSFETs. As CMOS technology continues to scale, metal gate electrodes need to be intro- duced to overcome the deleterious ...

  13. Efficient coupling of 527 nm laser beam power to a long scale-length plasma

    International Nuclear Information System (INIS)

    Moody, J.D.; Divol, L.; Glenzer, S.H.; MacKinnon, A.J.; Froula, D.H.; Gregori, G.; Kruer, W.L.; Meezan, N.B.; Suter, L.J.; Williams, E.A.; Bahr, R.; Seka, W.

    2006-01-01

    We experimentally demonstrate that application of laser smoothing schemes including smoothing by spectral dispersion (SSD) and polarization smoothing (PS) increases the intensity range for efficient coupling of frequency doubled (527 nm) laser light to a long scale-length plasma with n e /n cr equals 0.14 and T e equals 2 keV. (authors)

  14. Numerical scalings of the decay lengths in the scrape-off layer

    DEFF Research Database (Denmark)

    Militello, F.; Naulin, V; Nielsen, Anders Henry

    2013-01-01

    Numerical simulations of L-mode turbulence in the scrape-off layer (SOL) are used to construct power scaling laws for the characteristic decay lengths of the temperature, density and heat flux at the outer mid-plane. Most of the results obtained are in qualitative agreement with the experimental...

  15. Studying fractal geometry on submicron length scales by small-angle scattering

    International Nuclear Information System (INIS)

    Wong, P.; Lin, J.

    1988-01-01

    Recent studies have shown that internal surfaces of porous geological materials, such as rocks and lignite coals, can be described by fractals down to atomic length scales. In this paper, the basic properties of self-similar and self-affine fractals are reviewed and how fractal dimensions can be measured by small-angle scattering experiments are discussed

  16. Distinct Length Scales in the VO2 Metal-Insulator Transition Revealed by Bi-chromatic Optical Probing

    International Nuclear Information System (INIS)

    Wang, Lei; Novikova, Irina B.; Klopf, John M.; Madaras, Scott E.; Williams, Gwyn P.; Madaras, Eric; Lu, Liwei; Wolf, Stuart A.; Lukaszew, Rosa A.

    2014-01-01

    Upon a heating-induced metal-insulator transition (MIT) in VO 2 , microscopic metallic VO 2 puddles nucleate and coarsen within the insulating matrix. This coexistence of the two phases across the transition spans distinct length scales as their relative domain sizes change. Far-field optical probing is applied to follow the dynamic evolution of the highly correlated metallic domains as the MIT progresses

  17. Dependence of exponents on text length versus finite-size scaling for word-frequency distributions

    Science.gov (United States)

    Corral, Álvaro; Font-Clos, Francesc

    2017-08-01

    Some authors have recently argued that a finite-size scaling law for the text-length dependence of word-frequency distributions cannot be conceptually valid. Here we give solid quantitative evidence for the validity of this scaling law, using both careful statistical tests and analytical arguments based on the generalized central-limit theorem applied to the moments of the distribution (and obtaining a novel derivation of Heaps' law as a by-product). We also find that the picture of word-frequency distributions with power-law exponents that decrease with text length [X. Yan and P. Minnhagen, Physica A 444, 828 (2016), 10.1016/j.physa.2015.10.082] does not stand with rigorous statistical analysis. Instead, we show that the distributions are perfectly described by power-law tails with stable exponents, whose values are close to 2, in agreement with the classical Zipf's law. Some misconceptions about scaling are also clarified.

  18. Determining the minimal length scale of the generalized uncertainty principle from the entropy-area relationship

    International Nuclear Information System (INIS)

    Kim, Wontae; Oh, John J.

    2008-01-01

    We derive the formula of the black hole entropy with a minimal length of the Planck size by counting quantum modes of scalar fields in the vicinity of the black hole horizon, taking into account the generalized uncertainty principle (GUP). This formula is applied to some intriguing examples of black holes - the Schwarzschild black hole, the Reissner-Nordstrom black hole, and the magnetically charged dilatonic black hole. As a result, it is shown that the GUP parameter can be determined by imposing the black hole entropy-area relationship, which has a Planck length scale and a universal form within the near-horizon expansion

  19. Extending the length and time scales of Gram–Schmidt Lyapunov vector computations

    International Nuclear Information System (INIS)

    Costa, Anthony B.; Green, Jason R.

    2013-01-01

    Lyapunov vectors have found growing interest recently due to their ability to characterize systems out of thermodynamic equilibrium. The computation of orthogonal Gram–Schmidt vectors requires multiplication and QR decomposition of large matrices, which grow as N 2 (with the particle count). This expense has limited such calculations to relatively small systems and short time scales. Here, we detail two implementations of an algorithm for computing Gram–Schmidt vectors. The first is a distributed-memory message-passing method using Scalapack. The second uses the newly-released MAGMA library for GPUs. We compare the performance of both codes for Lennard–Jones fluids from N=100 to 1300 between Intel Nahalem/Infiniband DDR and NVIDIA C2050 architectures. To our best knowledge, these are the largest systems for which the Gram–Schmidt Lyapunov vectors have been computed, and the first time their calculation has been GPU-accelerated. We conclude that Lyapunov vector calculations can be significantly extended in length and time by leveraging the power of GPU-accelerated linear algebra

  20. Revisiting the Scale Length-μ0 Plane and the Freeman Law in the Local Universe

    Science.gov (United States)

    Fathi, Kambiz

    2010-10-01

    We have used Virtual Observatory technology to analyze the disk scale length rd and central surface brightness μ0 for a sample of 29,955 bright disk galaxies from the Sloan Digital Sky Survey. We use the results in the r band and revisit the relation between these parameters and the galaxy morphology, and find the average value langμ0rang = 20.2 ± 0.7 mag arcsec-2. We confirm that late-type spirals populate the lower left corner of the rd -μ0 plane and that the early and intermediate spirals are mixed in this diagram, with disky ellipticals at the top left corner. We further investigate the Freeman Law and confirm that it indeed defines an upper limit for μ0 in bright disk galaxies with r mag = 6) have fainter central surface brightness. Our results are based on a volume-corrected sample of galaxies in the local universe (z numerical simulations of galaxy formation and evolution.

  1. Length-scale effect due to periodic variation of geometrically necessary dislocation densities

    DEFF Research Database (Denmark)

    Oztop, M. S.; Niordson, Christian Frithiof; Kysar, J. W.

    2013-01-01

    Strain gradient plasticity theories have been successful in predicting qualitative aspects of the length scale effect, most notably the increase in yield strength and hardness as the size of the deforming volume decreases. However new experimental methodologies enabled by recent developments...... the microstructure of deformed metals in addition to the size effect. Recent GND measurements have revealed a distribution of length scales that evolves within a metal undergoing plastic deformation. Furthermore, these experiments have shown an accumulation of GND densities in cell walls as well as a variation...... of the saturation value of dislocation densities in these cell walls and dislocation structures. In this study, a strain gradient plasticity framework is extended by incorporating the physical quantities obtained from experimental observations: the quasi-periodicity and the saturation value of GND densities...

  2. The "lotus effect" explained: two reasons why two length scales of topography are important.

    Science.gov (United States)

    Gao, Lichao; McCarthy, Thomas J

    2006-03-28

    Surfaces containing 4 x 8 x 40 microm staggered rhombus posts were hydrophobized using two methods. One, using a dimethyldichlorosilane reaction in the vapor phase, introduces a smooth modified layer, and the other, a solution reaction using methyltrichlorosilane, imparts a second (nanoscopic) length scale of topography. The smooth modified surface exhibits contact angles of thetaA/thetaR = 176 degrees /156 degrees . Arguments are made that the pinning of the receding contact line by the post tops (with thetaA/thetaR = 104 degrees /103 degrees ) is responsible for the hysteresis. The second level of topography raises the contact angles of the post tops and the macroscopic sample to theta(A)/theta(R) = >176 degrees />176 degrees and eliminates hysteresis. The increase in Laplace pressure due to the increase in the advancing contact angle of the post tops is a second reason that two length scales of topography are important.

  3. The length-scale dependence of strain in networks by SANS

    CERN Document Server

    Pyckhout-Hintzen, W; Heinrich, M; Richter, D; Westermann, S; Straube, E

    2002-01-01

    We present a SANS study of the length-scale dependence of chain deformation by means of a suitable labeling in dense, cross-linked elastomers of the HDH-type. This length scale is controlled by the size of the label as well as the cross-link density. The results are compared to long homopolymers. The data are analyzed by means of the tube model of topology in rubber elasticity in combination with the random-phase approximation (RPA) to account for interchain correlations. Chain degradation during cross linking is treated by the standard RPA approach for polydisperse multicomponent systems. A transition from locally freely fluctuating to tube-constrained segmental motion was observed. (orig.)

  4. Observation of two length scales in the magnetic critical fluctuations of holmium

    International Nuclear Information System (INIS)

    Thurston, T.R.; Helgesen, G.; Gibbs, D.; Hill, J.P.; Gaulin, B.D.; Shirane, G.

    1993-01-01

    The short-ranged correlations associated with magneitc ordering in the rare earth antiferromagnet holmium have been characterized in high-resolution x-ray and neutron scattering studies. We find that within about 2 K of T c , the magnetic fluctuations exhibit two length scales, instead of one as expected in an ideal system. This result is reminiscent of behavior observed at the cubic-to-tegragonal structural phase transitions of the perovskites

  5. Length scale effects and multiscale modeling of thermally induced phase transformation kinetics in NiTi SMA

    Science.gov (United States)

    Frantziskonis, George N.; Gur, Sourav

    2017-06-01

    Thermally induced phase transformation in NiTi shape memory alloys (SMAs) shows strong size and shape, collectively termed length scale effects, at the nano to micrometer scales, and that has important implications for the design and use of devices and structures at such scales. This paper, based on a recently developed multiscale model that utilizes molecular dynamics (MDs) simulations at small scales and MD-verified phase field (PhF) simulations at larger scales, reports results on specific length scale effects, i.e. length scale effects in martensite phase fraction (MPF) evolution, transformation temperatures (martensite and austenite start and finish) and in the thermally cyclic transformation between austenitic and martensitic phase. The multiscale study identifies saturation points for length scale effects and studies, for the first time, the length scale effect on the kinetics (i.e. developed internal strains) in the B19‧ phase during phase transformation. The major part of the work addresses small scale single crystals in specific orientations. However, the multiscale method is used in a unique and novel way to indirectly study length scale and grain size effects on evolution kinetics in polycrystalline NiTi, and to compare the simulation results to experiments. The interplay of the grain size and the length scale effect on the thermally induced MPF evolution is also shown in this present study. Finally, the multiscale coupling results are employed to improve phenomenological material models for NiTi SMA.

  6. Image processing for quantifying fracture orientation and length scale transitions during brittle deformation

    Science.gov (United States)

    Rizzo, R. E.; Healy, D.; Farrell, N. J.

    2017-12-01

    We have implemented a novel image processing tool, namely two-dimensional (2D) Morlet wavelet analysis, capable of detecting changes occurring in fracture patterns at different scales of observation, and able of recognising the dominant fracture orientations and the spatial configurations for progressively larger (or smaller) scale of analysis. Because of its inherited anisotropy, the Morlet wavelet is proved to be an excellent choice for detecting directional linear features, i.e. regions where the amplitude of the signal is regular along one direction and has sharp variation along the perpendicular direction. Performances of the Morlet wavelet are tested against the 'classic' Mexican hat wavelet, deploying a complex synthetic fracture network. When applied to a natural fracture network, formed triaxially (σ1>σ2=σ3) deforming a core sample of the Hopeman sandstone, the combination of 2D Morlet wavelet and wavelet coefficient maps allows for the detection of characteristic scale orientation and length transitions, associated with the shifts from distributed damage to the growth of localised macroscopic shear fracture. A complementary outcome arises from the wavelet coefficient maps produced by increasing the wavelet scale parameter. These maps can be used to chart the variations in the spatial distribution of the analysed entities, meaning that it is possible to retrieve information on the density of fracture patterns at specific length scales during deformation.

  7. Differential scaling patterns of vertebrae and the evolution of neck length in mammals.

    Science.gov (United States)

    Arnold, Patrick; Amson, Eli; Fischer, Martin S

    2017-06-01

    Almost all mammals have seven vertebrae in their cervical spines. This consistency represents one of the most prominent examples of morphological stasis in vertebrae evolution. Hence, the requirements associated with evolutionary modifications of neck length have to be met with a fixed number of vertebrae. It has not been clear whether body size influences the overall length of the cervical spine and its inner organization (i.e., if the mammalian neck is subject to allometry). Here, we provide the first large-scale analysis of the scaling patterns of the cervical spine and its constituting cervical vertebrae. Our findings reveal that the opposite allometric scaling of C1 and C2-C7 accommodate the increase of neck bending moment with body size. The internal organization of the neck skeleton exhibits surprisingly uniformity in the vast majority of mammals. Deviations from this general pattern only occur under extreme loading regimes associated with particular functional and allometric demands. Our results indicate that the main source of variation in the mammalian neck stems from the disparity of overall cervical spine length. The mammalian neck reveals how evolutionary disparity manifests itself in a structure that is otherwise highly restricted by meristic constraints. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  8. Quantitative atom probe analysis of nanostructure containing clusters and precipitates with multiple length scales

    International Nuclear Information System (INIS)

    Marceau, R.K.W.; Stephenson, L.T.; Hutchinson, C.R.; Ringer, S.P.

    2011-01-01

    A model Al-3Cu-(0.05 Sn) (wt%) alloy containing a bimodal distribution of relatively shear-resistant θ' precipitates and shearable GP zones is considered in this study. It has recently been shown that the addition of the GP zones to such microstructures can lead to significant increases in strength without a decrease in the uniform elongation. In this study, atom probe tomography (APT) has been used to quantitatively characterise the evolution of the GP zones and the solute distribution in the bimodal microstructure as a function of applied plastic strain. Recent nuclear magnetic resonance (NMR) analysis has clearly shown strain-induced dissolution of the GP zones, which is supported by the current APT data with additional spatial information. There is significant repartitioning of Cu from the GP zones into the solid solution during deformation. A new approach for cluster finding in APT data has been used to quantitatively characterise the evolution of the sizes and shapes of the Cu containing features in the solid solution solute as a function of applied strain. -- Research highlights: → A new approach for cluster finding in atom probe tomography (APT) data has been used to quantitatively characterise the evolution of the sizes and shapes of the Cu containing features with multiple length scales. → In this study, a model Al-3Cu-(0.05 Sn) (wt%) alloy containing a bimodal distribution of relatively shear-resistant θ' precipitates and shearable GP zones is considered. → APT has been used to quantitatively characterise the evolution of the GP zones and the solute distribution in the bimodal microstructure as a function of applied plastic strain. → It is clearly shown that there is strain-induced dissolution of the GP zones with significant repartitioning of Cu from the GP zones into the solid solution during deformation.

  9. Lower Length Scale Model Development for Embrittlement of Reactor Presure Vessel Steel

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yongfeng [Idaho National Lab. (INL), Idaho Falls, ID (United States); Schwen, Daniel [Idaho National Lab. (INL), Idaho Falls, ID (United States); Chakraborty, Pritam [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bai, Xianming [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    This report summarizes the lower-length-scale effort during FY 2016 in developing mesoscale capabilities for microstructure evolution, plasticity and fracture in reactor pressure vessel steels. During operation, reactor pressure vessels are subject to hardening and embrittlement caused by irradiation induced defect accumulation and irradiation enhanced solute precipitation. Both defect production and solute precipitation start from the atomic scale, and manifest their eventual effects as degradation in engineering scale properties. To predict the property degradation, multiscale modeling and simulation are needed to deal with the microstructure evolution, and to link the microstructure feature to material properties. In this report, the development of mesoscale capabilities for defect accumulation and solute precipitation are summarized. A crystal plasticity model to capture defect-dislocation interaction and a damage model for cleavage micro-crack propagation is also provided.

  10. Relative telomere length is associated with a functional ...

    Indian Academy of Sciences (India)

    salting out method as previously described (Morales et al. 2009). DNA concentrations were quantified using a Qubit ... analysing the relative fluorescence from the sample reac- tions and to estimate the Cq values. ... corresponds to the Ct value at 74◦C read (telomere signal) and S corresponds to the Ct value at 88◦C read ...

  11. Self-Consistent Field Theories for the Role of Large Length-Scale Architecture in Polymers

    Science.gov (United States)

    Wu, David

    At large length-scales, the architecture of polymers can be described by a coarse-grained specification of the distribution of branch points and monomer types within a molecule. This includes molecular topology (e.g., cyclic or branched) as well as distances between branch points or chain ends. Design of large length-scale molecular architecture is appealing because it offers a universal strategy, independent of monomer chemistry, to tune properties. Non-linear analogs of linear chains differ in molecular-scale properties, such as mobility, entanglements, and surface segregation in blends that are well-known to impact rheological, dynamical, thermodynamic and surface properties including adhesion and wetting. We have used Self-Consistent Field (SCF) theories to describe a number of phenomena associated with large length-scale polymer architecture. We have predicted the surface composition profiles of non-linear chains in blends with linear chains. These predictions are in good agreement with experimental results, including from neutron scattering, on a range of well-controlled branched (star, pom-pom and end-branched) and cyclic polymer architectures. Moreover, the theory allows explanation of the segregation and conformations of branched polymers in terms of effective surface potentials acting on the end and branch groups. However, for cyclic chains, which have no end or junction points, a qualitatively different topological mechanism based on conformational entropy drives cyclic chains to a surface, consistent with recent neutron reflectivity experiments. We have also used SCF theory to calculate intramolecular and intermolecular correlations for polymer chains in the bulk, dilute solution, and trapped at a liquid-liquid interface. Predictions of chain swelling in dilute star polymer solutions compare favorably with existing PRISM theory and swelling at an interface helps explain recent measurements of chain mobility at an oil-water interface. In collaboration

  12. Increasing the Length of Parents' Birth-Related Leave

    DEFF Research Database (Denmark)

    Rasmussen, Astrid Würtz

    2010-01-01

    Investments in children are generally seen as investments in the future economy. In this study I focus on time investments in children as I investigate the long-term educational effects on children of increasing parents' birth-related leave from 14 to 20 weeks using a natural experiment from 1984...... in Denmark. The causal effect of the reform is identified using regression discontinuity design to compare a population sample of children born shortly before and shortly after the reform took effect. Results indicate that increasing parents' access to birth-related leave has no measurable effect on children......'s long-term educational outcomes. Mothers' incomes and career opportunities are slightly positively affected by the reform....

  13. Second-moment closures and length scales for weakly stratified turbulent shear flows

    Science.gov (United States)

    Baumert, Helmut; Peters, Hartmut

    2000-03-01

    For the special hydrodynamic situation of unbounded homogeneous shear layers, turbulence closure models of Mellor-Yamada type (MY) and k-ɛ type are put into a single canonical form. For this situation we show that conventional versions of MY and various k-ɛ versions lack a proper steady state, and are unable to simulate the most basic properties of stratified shear flows exemplified in, for example, the Rohr et al. [1988] experiments: exponential growth at sufficiently low gradient Richardson number (Rg), exponential decay at sufficiently large Rg, and a steady state in between. Proper choice of one special model parameter readily solves the problems. In the fairly general case of structural equilibrium (state of exponential evolution) in weakly to moderately stratified turbulence (Rg ≲ 0.25), the ratio between the Thorpe scale (or Ellison scale) and the Ozmidov scale varies like the gradient Richardson number (Rg) to the power 3/4, and the ratio of the Thorpe scale to the buoyancy scale varies like Rg1/2. Length scales predicted by our current model are consistent with laboratory measurements of Rohr et al. [1988], with large-eddy numerical simulations of Schumann and Gerz [1995], and with microstructure measurements from the 1987 Tropic Heat Experiment in the equatorial Pacific by Peters et al. [1995].

  14. Nature of the spin-glass phase at experimental length scales

    International Nuclear Information System (INIS)

    Alvarez Baños, R; Cruz, A; Fernandez, L A; Gil-Narvion, J M; Gordillo-Guerrero, A; Maiorano, A; Martin-Mayor, V; Monforte-Garcia, J; Perez-Gaviro, S; Ruiz-Lorenzo, J J; Seoane, B; Tarancon, A; Guidetti, M; Mantovani, F; Schifano, S F; Tripiccione, R; Marinari, E; Parisi, G; Muñoz Sudupe, A; Navarro, D

    2010-01-01

    We present a massive equilibrium simulation of the three-dimensional Ising spin glass at low temperatures. The Janus special-purpose computer has allowed us to equilibrate, using parallel tempering, L = 32 lattices down to T ≈ 0.64T c . We demonstrate the relevance of equilibrium finite size simulations to understanding experimental non-equilibrium spin glasses in the thermodynamical limit by establishing a time-length dictionary. We conclude that non-equilibrium experiments performed on a timescale of 1 h can be matched with equilibrium results on L ≈ 110 lattices. A detailed investigation of the probability distribution functions of the spin and link overlap, as well as of their correlation functions, shows that Replica Symmetry Breaking is the appropriate theoretical framework for the physically relevant length scales. Besides, we improve over existing methodologies in ensuring equilibration in parallel tempering simulations

  15. Characteristic length scale of input data in distributed models: implications for modeling grid size

    Science.gov (United States)

    Artan, G. A.; Neale, C. M. U.; Tarboton, D. G.

    2000-01-01

    The appropriate spatial scale for a distributed energy balance model was investigated by: (a) determining the scale of variability associated with the remotely sensed and GIS-generated model input data; and (b) examining the effects of input data spatial aggregation on model response. The semi-variogram and the characteristic length calculated from the spatial autocorrelation were used to determine the scale of variability of the remotely sensed and GIS-generated model input data. The data were collected from two hillsides at Upper Sheep Creek, a sub-basin of the Reynolds Creek Experimental Watershed, in southwest Idaho. The data were analyzed in terms of the semivariance and the integral of the autocorrelation. The minimum characteristic length associated with the variability of the data used in the analysis was 15 m. Simulated and observed radiometric surface temperature fields at different spatial resolutions were compared. The correlation between agreement simulated and observed fields sharply declined after a 10×10 m2 modeling grid size. A modeling grid size of about 10×10 m2 was deemed to be the best compromise to achieve: (a) reduction of computation time and the size of the support data; and (b) a reproduction of the observed radiometric surface temperature.

  16. Characteristic length scale of input data in distributed models: implications for modeling grain size

    Science.gov (United States)

    Artan, Guleid A.; Neale, C. M. U.; Tarboton, D. G.

    2000-01-01

    The appropriate spatial scale for a distributed energy balance model was investigated by: (a) determining the scale of variability associated with the remotely sensed and GIS-generated model input data; and (b) examining the effects of input data spatial aggregation on model response. The semi-variogram and the characteristic length calculated from the spatial autocorrelation were used to determine the scale of variability of the remotely sensed and GIS-generated model input data. The data were collected from two hillsides at Upper Sheep Creek, a sub-basin of the Reynolds Creek Experimental Watershed, in southwest Idaho. The data were analyzed in terms of the semivariance and the integral of the autocorrelation. The minimum characteristic length associated with the variability of the data used in the analysis was 15 m. Simulated and observed radiometric surface temperature fields at different spatial resolutions were compared. The correlation between agreement simulated and observed fields sharply declined after a 10×10 m2 modeling grid size. A modeling grid size of about 10×10 m2 was deemed to be the best compromise to achieve: (a) reduction of computation time and the size of the support data; and (b) a reproduction of the observed radiometric surface temperature.

  17. Association of Metatarsalgia After Hallux Valgus Correction With Relative First Metatarsal Length.

    Science.gov (United States)

    Nakagawa, Satoru; Fukushi, Jun-Ichi; Nakagawa, Takeshi; Mizu-Uchi, Hideki; Iwamoto, Yukihide

    2016-06-01

    Metatarsalgia is frequently associated with hallux valgus. The aim of this study was to evaluate how the relative length and position of the first metatarsal head influenced metatarsalgia and plantar callosities beneath the lesser metatarsal heads. A retrospective analysis of the clinical data and radiographs of 102 cases was performed at a mean follow-up of 16 months after biplane interlocking osteotomies. Clinical evaluation was made using the Japanese Society for Surgery of the Foot (JSSF) hallux scale. Radiologic evaluation was made with standard weight-bearing anteroposterior radiographs, and the hallux valgus angle (HVA), intermetatarsal 1-2 angle (IMA), distal metatarsal articular angulation (DMAA), and the sesamoid position were evaluated. Relative first metatarsal length (RML) was determined according to Nilsonne/Morton's technique. The mean preoperative HVA decreased from 37 to 3 degrees, and the mean IMA from 17 to 4 degrees. The mean JSSF-hallux score improved from 56 to 96 points. The mean preoperative area of plantar callosities decreased from 3.1 to 1.5 mm(2). Sixty percent of metatarsalgia cases improved, and 85% of painless callosities disappeared postoperatively. Among radiologic parameters, postoperative RML was most significantly associated with JSSF score (P < .0001) and the presence of postoperative metatarsalgia (P < .0001). Receiver operating characteristic analysis revealed that the RML cut-off point was -3 mm for avoiding metatarsalgia, with an area under the curve of 0.88, a specificity of 88%, and a sensitivity of 85%. Preservation of relative first metatarsal length during first metatarsal osteotomy was important to prevent postoperative metatarsalgia. Level IV, retrospective case series. © The Author(s) 2016.

  18. Length Scale Dependence of the Dynamic Properties of Hyaluronic Acid Solutions in the Presence of Salt

    Energy Technology Data Exchange (ETDEWEB)

    Horkay, Ferenc; Falus, Peter; Hecht, Anne-Marie; Geissler, Erik (CNRS-UMR); (NIH); (ILL)

    2010-12-07

    In solutions of the charged semirigid biopolymer hyaluronic acid in salt-free conditions, the diffusion coefficient D{sub NSE} measured at high transfer momentum q by neutron spin echo is more than an order of magnitude smaller than that determined by dynamic light scattering, D{sub DLS}. This behavior contrasts with neutral polymer solutions. With increasing salt content, D{sub DLS} approaches D{sub NSE}, which is independent of ionic strength. Contrary to theoretical expectation, the ion-polymer coupling, which dominates the low q dynamics of polyelectrolyte solutions, already breaks down at distance scales greater than the Debye-Hueckel length.

  19. Synchrotron X-Ray Scattering as a Tool for Characterising Catalysts on Multiple Length Scales

    International Nuclear Information System (INIS)

    Hudspeth, Jessica M.; Kvashnina, Kristina O.; Kimber, Simon A.J.; Mitchell, Edward P.

    2015-01-01

    Optimising the properties of catalysts for industrial processes requires a detailed knowledge of their structure and properties on multiple length scales. Synchrotron light sources are ideal tools for characterising catalysts for industrial R and D, providing data with high temporal and spatial resolution, under realistic operating conditions, in a non-destructive way. Here, we describe the different synchrotron techniques that can be employed to gain a wealth of complementary information, and highlight recent developments that have allowed remarkable insight to be gained into working catalytic systems. These techniques have the potential to guide future industrial catalyst design. (authors)

  20. Explanation of the values of Hack's drainage basin, river length scaling exponent

    Science.gov (United States)

    Hunt, A. G.

    2015-08-01

    Percolation theory can be used to find water flow paths of least resistance. The application of percolation theory to drainage networks allows identification of the range of exponent values that describe the tortuosity of rivers in real river networks, which is then used to generate the observed scaling between drainage basin area and channel length, a relationship known as Hack's law. Such a theoretical basis for Hack's law allows interpretation of the range of exponent values based on an assessment of the heterogeneity of the substrate.

  1. Brief communication: Possible explanation of the values of Hack's drainage basin, river length scaling exponent

    Science.gov (United States)

    Hunt, Allen G.

    2016-04-01

    Percolation theory can be used to find water flow paths of least resistance. Application of percolation theory to drainage networks allows identification of the range of exponent values that describe the tortuosity of rivers in real river networks, which is then used to generate the observed scaling between drainage basin area and channel length, a relationship known as Hack's law. Such a theoretical basis for Hack's law may allow interpretation of the range of exponent values based on an assessment of the heterogeneity of the substrate.

  2. A multiple length scale description of the mechanism of elastomer stretching

    DEFF Research Database (Denmark)

    Neuefeind, J.; Skov, Anne Ladegaard; Daniels, J. E.

    2016-01-01

    Conventionally, the stretching of rubber is modeled exclusively by rotations of segments of the embedded polymer chains; i.e. changes in entropy. However models have not been tested on all relevant length scales due to a lack of appropriate probes. Here we present a universal X-ray based method...... within the individual monomers, but among the contributions is also an elastic strain, acting between chains, which is 3-4 orders of magnitude smaller than the macroscopic strain, and of the opposite sign, i.e. extension of polymer chains in the direction perpendicular to the stretch. This may be due...

  3. Gate length scaling trends of drive current enhancement in CMOSFETs with dual stress overlayers and embedded-SiGe

    International Nuclear Information System (INIS)

    Flachowsky, S.; Wei, A.; Herrmann, T.; Illgen, R.; Horstmann, M.; Richter, R.; Salz, H.; Klix, W.; Stenzel, R.

    2008-01-01

    Strain engineering in MOSFETs using tensile nitride overlayer (TOL) films, compressive nitride overlayer (COL) films, and embedded-SiGe (eSiGe) is studied by extensive device experiments and numerical simulations. The scaling behavior was analyzed by gate length reduction down to 40 nm and it was found that drive current strongly depends on the device dimensions. The reduction of drain-current enhancement for short-channel devices can be attributed to two competing factors: shorter gate length devices have increased longitudinal and vertical stress components which should result in improved drain-currents. However, there is a larger degradation from external resistance as the gate length decreases, due to a larger voltage dropped across the external resistance. Adding an eSiGe stressor reduces the external resistance in the p-MOSFET, to the extent that the drive current improvement from COL continues to increase even down the shortest gate length studied. This is due to the reduced resistivity of SiGe itself and the SiGe valence band offset relative to Si, leading to a smaller silicide-active contact resistance. It demonstrates the advantage of combining eSiGe and COL, not only for increased stress, but also for parasitic resistance reduction to enable better COL drive current benefit

  4. Effects of fracture distribution and length scale on the equivalent continuum elastic compliance of fractured rock masses

    Directory of Open Access Journals (Sweden)

    Marte Gutierrez

    2015-12-01

    Full Text Available Fracture systems have strong influence on the overall mechanical behavior of fractured rock masses due to their relatively lower stiffness and shear strength than those of the rock matrix. Understanding the effects of fracture geometrical distribution, such as length, spacing, persistence and orientation, is important for quantifying the mechanical behavior of fractured rock masses. The relation between fracture geometry and the mechanical characteristics of the fractured rock mass is complicated due to the fact that the fracture geometry and mechanical behaviors of fractured rock mass are strongly dependent on the length scale. In this paper, a comprehensive study was conducted to determine the effects of fracture distribution on the equivalent continuum elastic compliance of fractured rock masses over a wide range of fracture lengths. To account for the stochastic nature of fracture distributions, three different simulation techniques involving Oda's elastic compliance tensor, Monte Carlo simulation (MCS, and suitable probability density functions (PDFs were employed to represent the elastic compliance of fractured rock masses. To yield geologically realistic results, parameters for defining fracture distributions were obtained from different geological fields. The influence of the key fracture parameters and their relations to the overall elastic behavior of the fractured rock mass were studied and discussed. A detailed study was also carried out to investigate the validity of the use of a representative element volume (REV in the equivalent continuum representation of fractured rock masses. A criterion was also proposed to determine the appropriate REV given the fracture distribution of the rock mass.

  5. Taylor-plasticity-based analysis of length scale effects in void growth

    KAUST Repository

    Liu, Junxian

    2014-09-25

    We have studied the void growth problem by employing the Taylor-based strain gradient plasticity theories, from which we have chosen the following three, namely, the mechanism-based strain gradient (MSG) plasticity (Gao et al 1999 J. Mech. Phys. Solids 47 1239, Huang et al 2000 J. Mech. Phys. Solids 48 99-128), the Taylor-based nonlocal theory (TNT; 2001 Gao and Huang 2001 Int. J. Solids Struct. 38 2615) and the conventional theory of MSG (CMSG; Huang et al 2004 Int. J. Plast. 20 753). We have addressed the following three issues which occur when plastic deformation at the void surface is unconstrained. (1) Effects of elastic deformation. Elasticity is essential for cavitation instability. It is therefore important to guarantee that the gradient term entering the Taylor model is the effective plastic strain gradient instead of the total strain gradient. We propose a simple elastic-plastic decomposition method. When the void size approaches the minimum allowable initial void size related to the maximum allowable geometrically necessary dislocation density, overestimation of the flow stress due to the negligence of the elastic strain gradient is on the order of lεY/R0 near the void surface, where l, εY and R0 are, respectively, the intrinsic material length scale, the yield strain and the initial void radius. (2) MSG intrinsic inconsistency, which was initially mentioned in Gao et al (1999 J. Mech. Phys. Solids 47 1239) but has not been the topic of follow-up studies. We realize that MSG higher-order stress arises due to the linear-strain-field approximation within the mesoscale cell with a nonzero size, lε. Simple analysis shows that within an MSG mesoscale cell near the void surface, the difference between microscale and mesoscale strains is on the order of (lε/R0)2, indicating that when lε/R0 ∼ 1.0, the higher-order stress effect can make the MSG result considerably different from the TNT or CMSG results. (3) Critical condition for cavitation instability

  6. Lead Selenide Nanostructures Self-Assembled across Multiple Length Scales and Dimensions

    Directory of Open Access Journals (Sweden)

    Evan K. Wujcik

    2016-01-01

    Full Text Available A self-assembly approach to lead selenide (PbSe structures that have organized across multiple length scales and multiple dimensions has been achieved. These structures consist of angstrom-scale 0D PbSe crystals, synthesized via a hot solution process, which have stacked into 1D nanorods via aligned dipoles. These 1D nanorods have arranged into nanoscale 2D sheets via directional short-ranged attraction. The nanoscale 2D sheets then further aligned into larger 2D microscale planes. In this study, the authors have characterized the PbSe structures via normal and cryo-TEM and EDX showing that this multiscale multidimensional self-assembled alignment is not due to drying effects. These PbSe structures hold promise for applications in advanced materials—particularly electronic technologies, where alignment can aid in device performance.

  7. Slinky-whistler dispersion relation from ``scaling''

    Science.gov (United States)

    Crawford, Frank S.

    1990-10-01

    Slinkies come in two sizes, ``regular'' and ``junior.'' Using 61% of the total length of the regular slinky, a whistler is obtained that sounds to the ear exactly like that obtained using the total length of the junior. That agrees with the proposed (approximate) dispersion relation ω=ck2r. If n is taken to be unknown in an assumed dispersion relation ω=ck(kr)n, then, by ear, with no equipment, it is found out n=0.83±0.17, in reasonable agreement with the proposed n=1.0.

  8. Strain rate, temperature and representative length scale influence on plasticity and yield stress in copper

    Energy Technology Data Exchange (ETDEWEB)

    Dupont, Virginie [Los Alamos National Laboratory; Germann, Timothy C [Los Alamos National Laboratory

    2011-01-18

    Shock compression of materials constitutes a complex process involving high strain rates, elevated temperatures and compression of the lattice. Materials properties are greatly affected by temperature, the representative length scale and the strain rate of the deformation. Experimentally, it is difficult to study the dynamic microscopic mechanisms that affect materials properties following high intensity shock loading, but they can be investigated using molecular dynamics (MD) simulations. Moreover, MD allows a better control over some parameters. We are using MD simulations to study the effect of the strain rate, representative length scale and temperature on the properties of metals during compression. A half-million-atom Cu sample is subjected to strain rates ranging from 10{sup 7} s{sup -1} to 10{sup 12} s{sup -1} at different temperatures ranging from 50K to 1500K. Single crystals as well as polycrystals are investigated. Plasticity mechanisms as well as the evolution of the micro- and macro-yield stress are observed. Our results show that the yield stress increases with increasing strain rate and decreasing temperature. We also show that the strain rate at which the transition between constant and increasing yield stress as a function of the temperature occurs increases with increasing temperature. Calculations at different grain sizes will give an insight into the grain size effect on the plasticity mechanisms and the yield stress.

  9. Origin of the second length scale found above TN in UO2

    International Nuclear Information System (INIS)

    Watson, G.M.; Gaulin, B.D.; Gibbs, D.; Thurston, T.R.; Simpson, P.J.; Shapiro, S.M.; Lander, G.H.; Matzke, H.; Wang, S.; Dudley, M.

    1996-01-01

    We present the results of x-ray- and neutron-scattering studies of the temperature dependence of the magnetic scattering exhibited by the type-I, triple-Q antiferromagnet UO 2 . Our neutron-scattering results are consistent with those of earlier studies, including the observation of short-ranged magnetic correlations at temperatures near and above T N . However, it is found by x-ray diffraction that a second, longer length scale is induced near T N when the near-surface volume of the sample is mechanically roughened. The longitudinal and transverse widths of the additional scattering increase continuously with increasing temperature above T N , similar to that which has been observed near the magnetic ordering transitions of Ho, Tb, and NpAs and near the tetragonal-to-cubic transitions of various perovskites. Another unusual feature of the present results for UO 2 involves the apparent shift with temperature of the magnetic scattering along the surface normal direction at the (1,1,0) reflection, but not at the (2,1,0) reflection. To our knowledge, this is the first observation of a second length scale near a first-order transition. copyright 1996 The American Physical Society

  10. A stochastic immersed boundary method for fluid-structure dynamics at microscopic length scales

    International Nuclear Information System (INIS)

    Atzberger, Paul J.; Kramer, Peter R.; Peskin, Charles S.

    2007-01-01

    In modeling many biological systems, it is important to take into account flexible structures which interact with a fluid. At the length scale of cells and cell organelles, thermal fluctuations of the aqueous environment become significant. In this work, it is shown how the immersed boundary method of [C.S. Peskin, The immersed boundary method, Acta Num. 11 (2002) 1-39.] for modeling flexible structures immersed in a fluid can be extended to include thermal fluctuations. A stochastic numerical method is proposed which deals with stiffness in the system of equations by handling systematically the statistical contributions of the fastest dynamics of the fluid and immersed structures over long time steps. An important feature of the numerical method is that time steps can be taken in which the degrees of freedom of the fluid are completely underresolved, partially resolved, or fully resolved while retaining a good level of accuracy. Error estimates in each of these regimes are given for the method. A number of theoretical and numerical checks are furthermore performed to assess its physical fidelity. For a conservative force, the method is found to simulate particles with the correct Boltzmann equilibrium statistics. It is shown in three dimensions that the diffusion of immersed particles simulated with the method has the correct scaling in the physical parameters. The method is also shown to reproduce a well-known hydrodynamic effect of a Brownian particle in which the velocity autocorrelation function exhibits an algebraic (τ -3/2 ) decay for long times [B.J. Alder, T.E. Wainwright, Decay of the Velocity Autocorrelation Function, Phys. Rev. A 1(1) (1970) 18-21]. A few preliminary results are presented for more complex systems which demonstrate some potential application areas of the method. Specifically, we present simulations of osmotic effects of molecular dimers, worm-like chain polymer knots, and a basic model of a molecular motor immersed in fluid subject to a

  11. On the Evolution of the Integral Length Scale in the Wake of Wind Turbines and within Wind Farms

    Science.gov (United States)

    Liu, Huiwen; Jin, Yaqing; Hayat, Imran; Chamorro, Leonardo P.

    2017-11-01

    Wind tunnel experiments were performed to characterize the evolution of integral length scale in the wake of a single turbine, and around wind farms. Hotwire anemometry was used to obtain high-resolution measurements of the streamwise velocity fluctuation at various locations. Negligible and high freestream turbulence levels were considered in the case of single turbine. The integral length scale along the rotor axis is found to grow nearly linearly with distance independent of the incoming turbulence levels, and appears to reach the incoming level in the high turbulence case at about 35-40 rotor diameters downstream. In the wind farm, results suggest that the distribution of integral length scale can be roughly described by a power-law growth with distance within consecutive turbines. Approximately past the third row, the integral length scale appears to reach equilibrium of the spatial distribution.

  12. Statistical theory and transition in multiple-scale-lengths turbulence in plasmas

    International Nuclear Information System (INIS)

    Itoh, Sanae-I.; Itoh, Kimitaka

    2001-06-01

    The statistical theory of strong turbulence in inhomogeneous plasmas is developed for the cases where fluctuations with different scale-lengths coexist. Nonlinear interactions in the same kind of fluctuations as well as nonlinear interplay between different classes of fluctuations are kept in the analysis. Nonlinear interactions are modelled as turbulent drag, nonlinear noise and nonlinear drive, and a set of Langevin equations is formulated. With the help of an Ansatz of a large number of degrees of freedom with positive Lyapunov number, Langevin equations are solved and the fluctuation dissipation theorem in the presence of strong plasma turbulence has been derived. A case where two driving mechanisms (one for micro mode and the other for semi-micro mode) coexist is investigated. It is found that there are several states of fluctuations: in one state, the micro mode is excited and the semi-micro mode is quenched; in the other state, the semi-micro mode is excited, and the micro mode remains at finite but suppressed level. New type of turbulence transition is obtained, and a cusp type catastrophe is revealed. A phase diagram is drawn for turbulence which is composed of multiple classes of fluctuations. Influence of the inhomogeneous global radial electric field is discussed. A new insight is given for the physics of internal transport barrier. Finally, the nonlocal heat transport due to the long-wave-length fluctuations, which are noise-pumped by shorter-wave-length ones, is analyzed and the impact on transient transport problems is discussed. (author)

  13. Fabrication of Cu-induced networks of linear nanostructures on different length scales

    International Nuclear Information System (INIS)

    Adelung, R.; Hartung, W.; Ernst, F.

    2002-01-01

    Scanning electron microscopy and atomic force microscopy revealed that the deposition Cu onto VSe 2 substrates in ultra-high vacuum leads to the self-organized formation of linear nanostructures, nanowires and nanotunnels, on the substrate surface. The nanowires and nanotunnels are approximately equi-axed and form networks with a mesh width much larger than their diameter. Surprisingly, systematic increase of the Cu coverage studied here does not simply increase the thickness of the nanowires and nanotunnels, but induces the formation of further, distinct networks with increased feature size and increased mesh width. At very high Cu coverages, eventually, we obtained a hierarchy of apparently independent nanowire and nanotunnel networks on different length scales. A model is presented for the micromechanism that leads to this complex arrangement of nanostructures

  14. Multi-length scale porous polymer films from hypercrosslinked breath figure arrays.

    Science.gov (United States)

    Ding, Lei; Zhang, Aijuan; Li, Wenqing; Bai, Hua; Li, Lei

    2016-01-01

    Multi-length scale porous polymer (MLSPP) films were fabricated using commercially available polystyrene (PS) via static breath figure (BF) process and sequent hypercrosslinking reaction. One level of ordered pores in microscale were introduced using static BF process, and the other level in nanoscale were produced by the sequent Friedel-Crafts hypercrosslinking reaction. The chemical structure of the PS MLSPP film was investigated by Fourier transformation infrared spectrometry and solid state nuclear magnetic resonance, and the morphology of the film was observed with electron microscopes. The MLSPP films showed large specific surface areas and excellent chemical and thermal stabilities, owing to the micropores and the crosslinked chemical structure produced by the Friedel-Crafts reaction. The methodology reported in this paper is a template-free, low cost and general strategy for the preparation of MLSPP films, which has potential applications in the areas of environment and energy. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Zebrafish brain mapping--standardized spaces, length scales, and the power of N and n.

    Science.gov (United States)

    Hunter, Paul R; Hendry, Aenea C; Lowe, Andrew S

    2015-06-01

    Mapping anatomical and functional parameters of the zebrafish brain is moving apace. Research communities undertaking such studies are becoming ever larger and more diverse. The unique features, tools, and technologies associated with zebrafish are propelling them as the 21st century model organism for brain mapping. Uniquely positioned as a vertebrate model system, the zebrafish enables imaging of anatomy and function at different length scales from intraneuronal compartments to sparsely distributed whole brain patterns. With a variety of diverse and established statistical modeling and analytic methods available from the wider brain mapping communities, the richness of zebrafish neuroimaging data is being realized. The statistical power of population observations (N) within and across many samples (n) projected onto a standardized space will provide vast databases for data-driven biological approaches. This article reviews key brain mapping initiatives at different levels of scale that highlight the potential of zebrafish brain mapping. By way of introduction to the next wave of brain mappers, an accessible introduction to the key concepts and caveats associated with neuroimaging are outlined and discussed. © 2014 Wiley Periodicals, Inc.

  16. Stuttering Frequency in Relation to Lexical Diversity, Syntactic Complexity, and Utterance Length

    Science.gov (United States)

    Wagovich, Stacy A.; Hall, Nancy E.

    2018-01-01

    Children's frequency of stuttering can be affected by utterance length, syntactic complexity, and lexical content of language. Using a unique small-scale within-subjects design, this study explored whether language samples that contain more stuttering have (a) longer, (b) syntactically more complex, and (c) lexically more diverse utterances than…

  17. Evaluating the accuracy of finite element models at reduced length scales

    Science.gov (United States)

    Kemp, Connor

    Finite element models are used frequently in both engineering and scientific research. While they can provide useful information as to the performance of materials, as length scales are decreased more sophisticated model descriptions are required. It is also important to develop methods by which existing models may be verified against experimental findings. The present study evaluates the ability of various finite element models to predict materials behaviour at length scales ranging from several microns to tens of nanometers. Considering this motivation, this thesis is provided in manuscript form with the bulk of material coming from two case studies. Following an overview of relevant literature in Chapter 2, Chapter 3 considers the nucleation of delta-zirconium hydrides in a Zircaloy-2 matrix. Zirconium hydrides are an important topic in the nuclear industry as they form a brittle phase which leads to delayed hydride cracking during reactor start-up and shut-down. Several FE models are used to compare present results with literature findings and illustrate the weaknesses of standard FE approaches. It is shown that standard continuum techniques do not sufficiently capture the interfacial effects of an inclusion-matrix system. By using nano-scale material descriptions, nucleation lattice strains are obtained which are in good agreement with previous experimental studies. The motivation for Chapter 4 stems from a recognized need to develop a method for modeling corrosion behaviour of materials. Corrosion is also an issue for reactor design and an ability to predict failure points is needed. Finite element models could be used for this purpose, provided model accuracy is verified first. In Chapter 4 a technique is developed which facilitates the extraction of sub-micron resolution strain data from correlation images obtained during in-situ tensile deformation. By comparing image correlation results with a crystal plasticity finite element code it is found that good

  18. Influence of the course boundary value problem on length scale parmeters for second-gradient continuum theories

    Energy Technology Data Exchange (ETDEWEB)

    Luscher, Darby J [Los Alamos National Laboratory; Bronkhorst, Curt A [Los Alamos National Laboratory; Mc Dowell, David L [GEORGIA TECH

    2010-12-20

    All nonlocal continuum descriptions of inelastic material response involve length scale parameters that either directly or implicitly quantify the physical dimensions of a neighborhood of response which influences the behavior at a particular point. The second-gradient continuum theories such as those developed by Germain, Toupin and Mindlin, and Eringen, and giving rise to strain-gradient plasticity, is becoming a common coarse-scale basis for homogenization of material response that respects the non local nature of heterogeneous material response. Ideally, the length scale parameters involved in such homogenization would be intrinsically associated with dominant aspects of the microstructure. However, these parameters, at least in some cases, are inextricably linked to the details of the coarse scale boundary value problem. Accordingly, they cannot be viewed as pure constitutive parameters. An example problem of multiscale homogenization is presented to underscore the dependence of second-gradient length scale parameters on the coarse scale boundary value problem, namely the multiscale response of an idealized porous microstructure. The fine scale (microstructure) comprises elastic perfectly plastic matrix with a periodic array of circular voids. This fine scale description of the problem is identical for two separate classes of coarse scale boundary value problem, viz. an extruded channel subject to compression and eventually developing plastic shear bands and a thin layer of material with larger (coarse scale) elliptical voids subject to shear deformation. Implications of the relationship between length scale parameters and the details of the coarse scale boundary value problem are discussed and ideas to ascertain such length parameters from evolving response fields are presented.

  19. Modified dispersion relations, inflation, and scale invariance

    Science.gov (United States)

    Bianco, Stefano; Friedhoff, Victor Nicolai; Wilson-Ewing, Edward

    2018-02-01

    For a certain type of modified dispersion relations, the vacuum quantum state for very short wavelength cosmological perturbations is scale-invariant and it has been suggested that this may be the source of the scale-invariance observed in the temperature anisotropies in the cosmic microwave background. We point out that for this scenario to be possible, it is necessary to redshift these short wavelength modes to cosmological scales in such a way that the scale-invariance is not lost. This requires nontrivial background dynamics before the onset of standard radiation-dominated cosmology; we demonstrate that one possible solution is inflation with a sufficiently large Hubble rate, for this slow roll is not necessary. In addition, we also show that if the slow-roll condition is added to inflation with a large Hubble rate, then for any power law modified dispersion relation quantum vacuum fluctuations become nearly scale-invariant when they exit the Hubble radius.

  20. On the evolution of cluster scaling relations

    International Nuclear Information System (INIS)

    Diemer, Benedikt; Kravtsov, Andrey V.; More, Surhud

    2013-01-01

    Understanding the evolution of scaling relations between the observable properties of clusters and their total mass is key to realizing their potential as cosmological probes. In this study, we investigate whether the evolution of cluster scaling relations is affected by the spurious evolution of mass caused by the evolving reference density with respect to which halo masses are defined (pseudo-evolution). We use the relation between mass, M, and velocity dispersion, σ, as a test case, and show that the deviation from the M-σ relation of cluster-sized halos caused by pseudo-evolution is smaller than 10% for a wide range of mass definitions. The reason for this small impact is a tight relation between the velocity dispersion and mass profiles, σ(relation is generically expected for a variety of density profiles, as long as halos are in approximate Jeans equilibrium. Thus, as the outer 'virial' radius used to define the halo mass, R, increases due to pseudo-evolution, halos approximately preserve their M-σ relation. This result highlights the fact that tight scaling relations are the result of tight equilibrium relations between radial profiles of physical quantities. We find exceptions at very small and very large radii, where the profiles deviate from the relations they exhibit at intermediate radii. We discuss the implications of these results for other cluster scaling relations and argue that pseudo-evolution should have a small effect on most scaling relations, except for those that involve the stellar masses of galaxies. In particular, we show that the relation between stellar-mass fraction and total mass is affected by pseudo-evolution and is largely shaped by it for halo masses ≲ 10 14 M ☉ .

  1. Failure analysis of fuel cell electrodes using three-dimensional multi-length scale X-ray computed tomography

    Science.gov (United States)

    Pokhrel, A.; El Hannach, M.; Orfino, F. P.; Dutta, M.; Kjeang, E.

    2016-10-01

    X-ray computed tomography (XCT), a non-destructive technique, is proposed for three-dimensional, multi-length scale characterization of complex failure modes in fuel cell electrodes. Comparative tomography data sets are acquired for a conditioned beginning of life (BOL) and a degraded end of life (EOL) membrane electrode assembly subjected to cathode degradation by voltage cycling. Micro length scale analysis shows a five-fold increase in crack size and 57% thickness reduction in the EOL cathode catalyst layer, indicating widespread action of carbon corrosion. Complementary nano length scale analysis shows a significant reduction in porosity, increased pore size, and dramatically reduced effective diffusivity within the remaining porous structure of the catalyst layer at EOL. Collapsing of the structure is evident from the combination of thinning and reduced porosity, as uniquely determined by the multi-length scale approach. Additionally, a novel image processing based technique developed for nano scale segregation of pore, ionomer, and Pt/C dominated voxels shows an increase in ionomer volume fraction, Pt/C agglomerates, and severe carbon corrosion at the catalyst layer/membrane interface at EOL. In summary, XCT based multi-length scale analysis enables detailed information needed for comprehensive understanding of the complex failure modes observed in fuel cell electrodes.

  2. Length Scales of Reactive Transport in Basalt: Hydrothermal Flow-through Experiments and Anhydrite Precipitation

    Science.gov (United States)

    Los, C.; Kahl, W. A.; Bach, W.

    2017-12-01

    Hydrothermal circulation is a large contributor to mass and heat exchange between oceanic lithosphere and hydrosphere. Cold, unaltered seawater infiltrates in the shallow basaltic crust, leading to sulfate precipitation and clogging of fluid pathways. Anhydrite (CaSO4) veins are common in hydrothermal discharge zones, where entrained seawater is heated and anhydrite quickly forms. Anhydrite is also found in hydrothermal recharge zones, but questions regarding time and length scale in this setting remain. To investigate element transport and anhydrite precipitation we have conducted flow-through experiments using a gypsum-undersaturated CaSO4 solution in pre-fractured basalt at 95, 110 and 140°C. Each run was terminated upon clogging of the input tubes, which took 2-8 weeks. The rock core was scanned before the run and weekly during the experiment using X-ray tomography. Fluid major element chemistry was analyzed using ICP-OES. Geochemical modeling with the software package EQ3/6 showed that the starting solution became supersaturated in anhydrite (SI=IAP/K of 2.5 or higher) in all cases upon heating to the experimental temperature. The software CRUNCH FLOW was used to analyze chemical effects over the length of the core (3cm). The 95°C run and a first run at 110°C did not show any anhydrite. Instead, hematite rosettes and sulfur-bearing (maximum of 1 wt.%) globular Fe-rich structures were present. Tomography images showed that fractures and pores were slightly thinned over the whole core length. Single pores in a second 110°C run and fractures in the 140°C run did show formation of anhydrite and quartz close to the outlet. CRUNCH FLOW modeling predicts the observed release of Mg, Fe, Si, Al, Na and K due to silicate dissolution close to the inlet, while the outlet area should contain some anhydrite. No other sulfur-bearing phases were predicted. The results of this study show that anhydrite needs a large supersaturation (SI>2.5) to precipitate at temperatures

  3. Instantaneous equations for multiphase flow in porous media without length-scale restrictions using a non-local averaging volume

    International Nuclear Information System (INIS)

    Espinosa-Paredes, Gilberto

    2010-01-01

    The aim of this paper is to propose a framework to obtain a new formulation for multiphase flow conservation equations without length-scale restrictions, based on the non-local form of the averaged volume conservation equations. The simplification of the local averaging volume of the conservation equations to obtain practical equations is subject to the following length-scale restrictions: d << l << L, where d is the characteristic length of the dispersed phases, l is the characteristic length of the averaging volume, and L is the characteristic length of the physical system. If the foregoing inequality does not hold, or if the scale of the problem of interest is of the order of l, the averaging technique and therefore, the macroscopic theories of multiphase flow should be modified in order to include appropriate considerations and terms in the corresponding equations. In these cases the local form of the averaged volume conservation equations are not appropriate to describe the multiphase system. As an example of the conservation equations without length-scale restrictions, the natural circulation boiling water reactor was consider to study the non-local effects on the thermal-hydraulic core performance during steady-state and transient behaviors, and the results were compared with the classic local averaging volume conservation equations.

  4. Some problems of special theory of relativity. (Concept of relativistic length)

    International Nuclear Information System (INIS)

    Strel'tsov, V.N.

    1977-01-01

    Two available definitions of the concept of length (distance) related (a) to moving the length standard and (b) to sending a light signal (similar to the radar method for measuring distances) are analyzed. Considerations in favour of the preferable use of the (b) definition are discussed. The extension of the (b) definition for fast moving bodies results in the introduction of the definition of relativistic length and volume. The increase of the longitudinal dimensions of fast moving objects is a consequence of the above definition. It should be noted that, e.g., for a rod, the definition corresponds to measurements on the lines orthogonal to the world strip of the given rod. It is shown that the known Michelson-Morley and Throuton-Noble experiments are naturally explained in the framework of the proposed concept of relativistic length. It is also shown that the definition introduced, unlike the conventional one, satisfies the principle of relativity

  5. Scaling relations for eddy current phenomena

    International Nuclear Information System (INIS)

    Dodd, C.V.; Deeds, W.E.

    1975-11-01

    Formulas are given for various electromagnetic quantities for coils in the presence of conductors, with the scaling parameters factored out so that small-scale model experiments can be related to large-scale apparatus. Particular emphasis is given to such quantities as eddy current heating, forces, power, and induced magnetic fields. For axially symmetric problems, closed-form integrals are available for the vector potential and all the other quantities obtainable from it. For unsymmetrical problems, a three-dimensional relaxation program can be used to obtain the vector potential and then the derivable quantities. Data on experimental measurements are given to verify the validity of the scaling laws for forces, inductances, and impedances. Indirectly these also support the validity of the scaling of the vector potential and all of the other quantities obtained from it

  6. Heritage and scale: settings, boundaries and relations

    DEFF Research Database (Denmark)

    Harvey, David

    2015-01-01

    of heritage, as well as ‘upscaling’, towards a universal understanding of heritage. While such work has had critical impact within prescribed scalar boundaries, we need to build a theoretical understanding of what an emergent relationship between heritage and scale does within the context of dynamic power...... relations. This paper examines how heritage is produced and practised, consumed and experienced, managed and deployed at a variety of scales, exploring how notions of scale, territory and boundedness have a profound effect on the heritage process. Drawing on the work of Doreen Massey and others, the paper...

  7. Low frequency energy scavenging using sub-wave length scale acousto-elastic metamaterial

    Directory of Open Access Journals (Sweden)

    Riaz U. Ahmed

    2014-11-01

    Full Text Available This letter presents the possibility of energy scavenging (ES utilizing the physics of acousto-elastic metamaterial (AEMM at low frequencies (<∼3KHz. It is proposed to use the AEMM in a dual mode (Acoustic Filter and Energy Harvester, simultaneously. AEMM’s are typically reported for filtering acoustic waves by trapping or guiding the acoustic energy, whereas this letter shows that the dynamic energy trapped inside the soft constituent (matrix of metamaterials can be significantly harvested by strategically embedding piezoelectric wafers in the matrix. With unit cell AEMM model, we experimentally asserted that at lower acoustic frequencies (< ∼3 KHz, maximum power in the micro Watts (∼35µW range can be generated, whereas, recently reported phononic crystal based metamaterials harvested only nano Watt (∼30nW power against 10KΩ resistive load. Efficient energy scavengers at low acoustic frequencies are almost absent due to large required size relevant to the acoustic wavelength. Here we report sub wave length scale energy scavengers utilizing the coupled physics of local, structural and matrix resonances. Upon validation of the argument through analytical, numerical and experimental studies, a multi-frequency energy scavenger (ES with multi-cell model is designed with varying geometrical properties capable of scavenging energy (power output from ∼10µW – ∼90µW between 0.2 KHz and 1.5 KHz acoustic frequencies.

  8. Genetic variability of the stable fly assessed on a global scale using amplified fragment length polymorphism.

    Science.gov (United States)

    Kneeland, Kathleen M; Skoda, Steven R; Foster, John E

    2016-10-01

    The stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), is a blood-feeding, economically important pest of animals and humans worldwide. Improved management strategies are essential and their development would benefit from studies on genetic diversity of stable flies. Especially if done on a global scale, such research could generate information necessary for the development and application of more efficient control methods. Herein we report on a genetic study of stable flies using amplified fragment length polymorphism, with samples of 10-40 individuals acquired from a total of 25 locations in the Nearctic, Neotropic, Palearctic, Afrotropic and Australasian biogeographical regions. We hypothesized that genetic differentiation would exist across geographical barriers. Although FST (0.33) was moderately high, the GST (0.05; representing genetic diversity between individuals) was very low; Nm values (representing gene flow) were high (9.36). The mismatch distribution and tests of neutrality suggested population expansion, with no genetic differentiation between locations. The analysis of molecular variance (AMOVA) results showed the majority of genetic diversity was within groups. The mantel test showed no correlation between geographic and genetic distance; this strongly supports the AMOVA results. These results suggest that stable flies did not show genetic differentiation but are panmictic, with no evidence of isolation by distance or across geographical barriers. © 2015 Institute of Zoology, Chinese Academy of Sciences.

  9. Relevant time- and length scale of touch-down for drops impacting on a heated surface

    Science.gov (United States)

    van Limbeek, Michiel A. J.; Shirota, Minori; Sun, Chao; Prosperetti, Andrea; Lohse, Detlef

    2015-11-01

    The vapor generated from a liquid drop impacting a hot solid surface can prevent it to make contact, depending on the solid temperature. The minimum temperature when no contact is made between the drop and the solid is called the dynamic Leidenfrost temperature. The latent heat needed to generated the vapor is drawn from the solid, and in general the Leidenfrost temperature depends on the solid thermal properties. Here we show experiments conducted on a sapphire plate, to minimize the cooling of the solid and ensuring nearly isothermal conditions. By using high speed total internal reflection imaging, we observe the drop base during impact up to about 100nm above the substrate surface. By this technique we are able to study the processes responsible for the transition between fully wetting and fully levitating drop impact conditions as the solid temperature increases. We reveal the relevant length- and time-scales for the dimple formation under the drop and explain their relevance for the late-time dynamics. As the transition regime is traversed from low to high temperature, the liquid-solid contact gradually decreases which reduces the friction with the solid, enhancing the spreading of the drop considerably.

  10. Bifurcation and phase diagram of turbulence constituted from three different scale-length modes

    International Nuclear Information System (INIS)

    Itoh, S.-I.; Kitazawa, A.; Yagi, M.; Itoh, K.

    2002-04-01

    Cases where three kinds of fluctuations having the different typical scale-lengths coexist are analyzed, and the statistical theory of strong turbulence in inhomogeneous plasmas is developed. Statistical nonlinear interactions between fluctuations are kept in the analysis as the renormalized drag, statistical noise and the averaged drive. The nonlinear interplay through them induces a quenching or suppressing effect, even if all the modes are unstable when they are analyzed independently. Variety in mode appearance takes place: one mode quenches the other two modes, or one mode is quenched by the other two modes, etc. The bifurcation of turbulence is analyzed and a phase diagram is drawn. Phase diagrams with cusp type catastrophe and butterfly type catastrophe are obtained. The subcritical bifurcation is possible to occur through the nonlinear interplay, even though each one is supercritical turbulence when analyzed independently. Analysis reveals that the nonlinear stability boundary (marginal point) and the amplitude of each mode may substantially shift from the conventional results of independent analyses. (author)

  11. Cellular adaptation to biomechanical stress across length scales in tissue homeostasis and disease.

    Science.gov (United States)

    Gilbert, Penney M; Weaver, Valerie M

    2017-07-01

    Human tissues are remarkably adaptable and robust, harboring the collective ability to detect and respond to external stresses while maintaining tissue integrity. Following injury, many tissues have the capacity to repair the damage - and restore form and function - by deploying cellular and molecular mechanisms reminiscent of developmental programs. Indeed, it is increasingly clear that cancer and chronic conditions that develop with age arise as a result of cells and tissues re-implementing and deregulating a selection of developmental programs. Therefore, understanding the fundamental molecular mechanisms that drive cell and tissue responses is a necessity when designing therapies to treat human conditions. Extracellular matrix stiffness synergizes with chemical cues to drive single cell and collective cell behavior in culture and acts to establish and maintain tissue homeostasis in the body. This review will highlight recent advances that elucidate the impact of matrix mechanics on cell behavior and fate across these length scales during times of homeostasis and in disease states. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Quantum chaos of a particle in a square well: Competing length scales and dynamical localization

    Science.gov (United States)

    Sankaranarayanan, R.; Lakshminarayan, A.; Sheorey, V. B.

    2001-10-01

    The classical and quantum dynamics of a particle trapped in a one-dimensional infinite square well with a time-periodic pulsed field is investigated. This is a two-parameter non-KAM (Kolmogorov-Arnold-Moser) generalization of the kicked rotor, which can be seen as the standard map of particles subjected to both smooth and hard potentials. The virtue of the generalization lies in the introduction of an extra parameter R, which is the ratio of two length scales, namely, the well width and the field wavelength. If R is a noninteger the dynamics is discontinuous and non-KAM. We have explored the role of R in controlling the localization properties of the eigenstates. In particular, the connection between classical diffusion and localization is found to generalize reasonably well. In unbounded chaotic systems such as these, while the nearest neighbor spacing distribution of the eigenvalues is less sensitive to the nature of the classical dynamics, the distribution of participation ratios of the eigenstates proves to be a sensitive measure; in the chaotic regimes the latter is log-normal. We find that the tails of the well converged localized states are exponentially localized despite the discontinuous dynamics while the bulk part shows fluctuations that tend to be closer to random matrix theory predictions. Time evolving states show considerable R dependence, and tuning R to enhance classical diffusion can lead to significantly larger quantum diffusion for the same field strengths, an effect that is potentially observable in present day experiments.

  13. Surface-immobilized hydrogel patterns on length scales from micrometer to nanometer

    Science.gov (United States)

    Zeira, Assaf

    The present work concentrates on the study of pattern generation and transfer processes of monolayer covered surfaces, deriving from the basic working concept of Constructive Lithography. As an advancement of constructive lithography, we developed a direct, one-step printing (contact electrochemical printing, CEP) and replication (contact electrochemical replication, CER) of hydrophilic organic monolayer patterns surrounded by a hydrophobic monolayer background. In addition, we present a process of transfer of metal between two contacting solid surfaces to predefined monolayer template pattern sites (contact electrochemical transfer, CET). This thesis shows that CEP, CER, and CET may be implemented under a variety of different experimental conditions, regardless of whether the initial "master" pattern was created by a parallel (fast) or serial (slow) patterning process. CEP and CER also posses the unique attractive property that each replica may equally function as master stamp in the fabrication of additional replicas. Moreover, due to a mechanism of selfcorrection patterned surfaces produced these process are often free of defects that the initial "master" stamp may had. We finally show that the electrochemical patterning of OTS monolayers on silicon can be further extended to flexible polymeric substrate materials as well as to a variety of chemical manipulations, allowing the fabrication of tridimensional (3D) composite structures made on the basis of readily available OTS compound. The results obtained suggest that such contact electrochemical processes could be used to rapidly generate multiple copies of surface patterns spanning variable length scales, this basic approach being applicable to rigid as well as flexible substrate materials.

  14. Comparison of the Effects of the Different Methods for Computing the Slope Length Factor at a Watershed Scale

    Directory of Open Access Journals (Sweden)

    Fu Suhua

    2013-09-01

    Full Text Available The slope length factor is one of the parameters of the Universal Soil Loss Equation (USLE and the Revised Universal Soil Loss Equation (RUSLE and is sometimes calculated based on a digital elevation model (DEM. The methods for calculating the slope length factor are important because the values obtained may depend on the methods used for calculation. The purpose of this study was to compare the difference in spatial distribution of the slope length factor between the different methods at a watershed scale. One method used the uniform slope length factor equation (USLFE where the effects of slope irregularities (such as slope gradient, etc. on soil erosion by water were not considered. The other method used segmented slope length factor equation(SSLFE which considered the effects of slope irregularities on soil erosion by water. The Arc Macro Language (AML Version 4 program for the revised universal soil loss equation(RUSLE.which uses the USLFE, was chosen to calculate the slope length factor. In a parallel analysis, the AML code of RUSLE Version 4 was modified according to the SSLFE to calculate the slope length factor. Two watersheds with different slope and gully densities were chosen. The results show that the slope length factor and soil loss using the USLFE method were lower than those using the SSLFE method, especially on downslopes watershed with more frequent steep slopes and higher gully densities. In addition, the slope length factor and soil loss calculated by the USLFE showed less spatial variation.

  15. DOES THE MILKY WAY OBEY SPIRAL GALAXY SCALING RELATIONS?

    Energy Technology Data Exchange (ETDEWEB)

    Licquia, Timothy C.; Newman, Jeffrey A. [Department of Physics and Astronomy, University of Pittsburgh, 3941 O’Hara Street, Pittsburgh, PA 15260 (United States); Bershady, Matthew A., E-mail: tcl15@pitt.edu, E-mail: janewman@pitt.edu, E-mail: mab@astro.wisc.edu [Department of Astronomy, University of Wisconsin, 475 N. Charter St., Madison, WI 53706 (United States)

    2016-12-20

    It is crucial to understand how the Milky Way (MW), the galaxy we can study in the most intimate detail, fits in among other galaxies. Key considerations include the Tully–Fisher relation (TFR)—i.e., the tight correlation between luminosity ( L ) and rotational velocity ( V {sub rot})—and the three-dimensional luminosity–velocity–radius ( LVR ) scaling relation. Several past studies have characterized the MW as a 1–1.5 σ outlier to the TFR. This study re-examines such comparisons using new estimates of MW properties that are robust to many of the systematic uncertainties that have been a problem in the past and are based on assumptions consistent with those used for other spiral galaxies. Comparing to scaling relations derived from modern extragalactic data, we find that our Galaxy’s properties are in excellent agreement with TFRs defined using any Sloan Digital Sky Survey-filter absolute magnitude, stellar mass, or baryonic mass as the L proxy. We next utilize disk scale length ( R {sub d}) measurements to extend this investigation to the LVR relation. Here we find that our Galaxy lies farther from the relation than ∼90% of other spiral galaxies, yielding ∼9.5 σ evidence that it is unusually compact for its L and V {sub rot} (based on MW errors alone), a result that holds for all of the L proxies considered. The expected R {sub d} for the MW from the LVR relation is ∼5 kpc, nearly twice as large as the observed value, with error estimates placing the two in tension at the ∼1.4 σ level. The compact scale length of the Galactic disk could be related to other ways in which the MW has been found to be anomalous.

  16. Diffusion effects on volume-selective NMR at small length scales

    International Nuclear Information System (INIS)

    Gaedke, Achim

    2009-01-01

    In this thesis, the interplay between diffusion and relaxation effects in spatially selective NMR experiments at short length scales is explored. This is especially relevant in the context of both conventional and mechanically detected MRI at (sub)micron resolution in biological specimens. Recent results on selectively excited very thin slices showed an in-slice-magnetization recovery orders of magnitude faster than the longitudinal relaxation time T1. However, those experiments were run on fully relaxed samples while MRI and especially mechanically detected NMR experiments are typically run in a periodic fashion with repetition times far below T1. The main purpose of this work therefore was to extend the study of the interplay between diffusion and longitudinal relaxation to periodic excitations. In some way, this is inverse phenomenon to the DESIRE (Diffusive Enhancement of SIgnal and REsolution) approach, proposed 1992 by Lauterbur. Experiments on periodically excited thin slices were carried out at a dedicated static field gradient cryomagnet with magnetic field gradients up to 180 T/m. In order to obtain plane slices, an appropriate isosurface of the gradient magnet had to be identified. It was found at a field of 3.8 T with a gradient of 73 T/m. In this field, slices down to a thickness of 3.2 μm could be excited. The detection of the NMR signal was done using FIDs instead of echoes as the excitation bandwidth of those thin slices is sufficiently small to observe FIDs which are usually considered to be elusive to detection in such strong static field gradients. A simulation toolbox based on the full Bloch-Torrey-equation was developed to describe the excitation and the formation of NMR signals under those unusual conditions as well as the interplay of diffusion and magnetization recovery. Both the experiments and the simulations indicate that diffusion effects lead to a strongly enhanced magnetization modulation signal also under periodic excitation

  17. The Sensitivity of Income Polarization - Time, length of accounting periods, equivalence scales, and income definitions

    DEFF Research Database (Denmark)

    Azhar, Hussain

    This study looks at polarization and its components’ sensitivity to assumptions about equivalence scales, income definition, ethical income distribution parameters, and the income accounting period. A representative sample of Danish individual incomes from 1984 to 2002 is utilised. Results show...... that polarization has increased over time, regardless of the applied measure, when the last part of the period is compared to the first part of the period. Primary causes being increased inequality (alienation) and faster income growth among high incomes relative to those in the middle of the distribution...

  18. Cosmology and cluster halo scaling relations

    NARCIS (Netherlands)

    Araya-Melo, Pablo A.; van de Weygaert, Rien; Jones, Bernard J. T.

    2009-01-01

    We explore the effects of dark matter and dark energy on the dynamical scaling properties of galaxy clusters. We investigate the cluster Faber-Jackson (FJ), Kormendy and Fundamental Plane (FP) relations between the mass, radius and velocity dispersion of cluster-sized haloes in cosmological N-body

  19. Ion-beam induced transformations in nanoscale multilayers: Evolution of clusters with preferred length scales

    Science.gov (United States)

    Bera, S.; Satpati, B.; Goswami, D. K.; Bhattacharjee, K.; Satyam, P. V.; Dev, B. N.

    2006-04-01

    Ion-irradiation-induced modifications of a periodic Pt/C multilayer system containing a small amount of Fe have been analyzed by transmission electron microscopy and grazing incidence x-ray diffraction (GIXRD) studies. The multilayer stack with 16 Pt/C layer pairs (period of 4.23 nm) was fabricated on a glass substrate. A 2 MeV Au2+ ion beam was rastered on the sample to obtain uniformly irradiated strips with fluences from 1×1014 to 1×1015 ions/cm2. Ion irradiation has been found to cause preferential migration of Fe towards Pt layers [Bera et al., Nucl. Instrum. Methods Phys. Res. B 212, 530 (2003)]. Cross-sectional transmission electron microscopy (XTEM) shows considerable atomic redistribution for irradiation at the highest ion fluence (1×1015 ions/cm2). This structure is composed of small clusters. Phase separation and cluster formation processes are discussed. Periodic multilayers have periodicity only in the direction normal to the multilayer surface. However, Fourier transform (FT) of the XTEM images of the sample irradiated at the highest fluence shows extra off-normal Fourier components of superlattice periodicities arising due to ion irradiation. These extra spots in the FT are due to preferential length scales in intercluster separation in three dimensions. With a proper understanding of this phenomenon it may be possible to fabricate useful three-dimensional self-assembled structures of nanoclusters. Our high resolution transmission electron microscopy and GIXRD results reveal the formation of an FePt alloy. As FePt is a magnetic alloy, our observation raises the possibility of fabrication of ion-beam induced magnetic nanocluster lattices.

  20. Ion-beam induced transformations in nanoscale multilayers: Evolution of clusters with preferred length scales

    International Nuclear Information System (INIS)

    Bera, S.; Satpati, B.; Goswami, D. K.; Bhattacharjee, K.; Satyam, P. V.; Dev, B. N.

    2006-01-01

    Ion-irradiation-induced modifications of a periodic Pt/C multilayer system containing a small amount of Fe have been analyzed by transmission electron microscopy and grazing incidence x-ray diffraction (GIXRD) studies. The multilayer stack with 16 Pt/C layer pairs (period of 4.23 nm) was fabricated on a glass substrate. A 2 MeV Au 2+ ion beam was rastered on the sample to obtain uniformly irradiated strips with fluences from 1x10 14 to 1x10 15 ions/cm 2 . Ion irradiation has been found to cause preferential migration of Fe towards Pt layers [Bera et al., Nucl. Instrum. Methods Phys. Res. B 212, 530 (2003)]. Cross-sectional transmission electron microscopy (XTEM) shows considerable atomic redistribution for irradiation at the highest ion fluence (1x10 15 ions/cm 2 ). This structure is composed of small clusters. Phase separation and cluster formation processes are discussed. Periodic multilayers have periodicity only in the direction normal to the multilayer surface. However, Fourier transform (FT) of the XTEM images of the sample irradiated at the highest fluence shows extra off-normal Fourier components of superlattice periodicities arising due to ion irradiation. These extra spots in the FT are due to preferential length scales in intercluster separation in three dimensions. With a proper understanding of this phenomenon it may be possible to fabricate useful three-dimensional self-assembled structures of nanoclusters. Our high resolution transmission electron microscopy and GIXRD results reveal the formation of an FePt alloy. As FePt is a magnetic alloy, our observation raises the possibility of fabrication of ion-beam induced magnetic nanocluster lattices

  1. In situ spatiotemporal mapping of flow fields around seeded stem cells at the subcellular length scale.

    Directory of Open Access Journals (Sweden)

    Min Jae Song

    2010-09-01

    Full Text Available A major hurdle to understanding and exploiting interactions between the stem cell and its environment is the lack of a tool for precise delivery of mechanical cues concomitant to observing sub-cellular adaptation of structure. These studies demonstrate the use of microscale particle image velocimetry (μ-PIV for in situ spatiotemporal mapping of flow fields around mesenchymal stem cells, i.e. murine embryonic multipotent cell line C3H10T1/2, at the subcellular length scale, providing a tool for real time observation and analysis of stem cell adaptation to the prevailing mechanical milieu. In the absence of cells, computational fluid dynamics (CFD predicts flow regimes within 12% of μ-PIV measures, achieving the technical specifications of the chamber and the flow rates necessary to deliver target shear stresses at a particular height from the base of the flow chamber. However, our μ-PIV studies show that the presence of cells per se as well as the density at which cells are seeded significantly influences local flow fields. Furthermore, for any given cell or cell seeding density, flow regimes vary significantly along the vertical profile of the cell. Hence, the mechanical milieu of the stem cell exposed to shape changing shear stresses, induced by fluid drag, varies with respect to proximity of surrounding cells as well as with respect to apical height. The current study addresses a previously unmet need to predict and observe both flow regimes as well as mechanoadaptation of cells in flow chambers designed to deliver precisely controlled mechanical signals to live cells. An understanding of interactions and adaptation in response to forces at the interface between the surface of the cell and its immediate local environment may be key for de novo engineering of functional tissues from stem cell templates as well as for unraveling the mechanisms underlying multiscale development, growth and adaptation of organisms.

  2. Universal Scaling Relations in Scale-Free Structure Formation

    Science.gov (United States)

    Guszejnov, Dávid; Hopkins, Philip F.; Grudić, Michael Y.

    2018-04-01

    A large number of astronomical phenomena exhibit remarkably similar scaling relations. The most well-known of these is the mass distribution dN/dM∝M-2 which (to first order) describes stars, protostellar cores, clumps, giant molecular clouds, star clusters and even dark matter halos. In this paper we propose that this ubiquity is not a coincidence and that it is the generic result of scale-free structure formation where the different scales are uncorrelated. We show that all such systems produce a mass function proportional to M-2 and a column density distribution with a power law tail of dA/d lnΣ∝Σ-1. In the case where structure formation is controlled by gravity the two-point correlation becomes ξ2D∝R-1. Furthermore, structures formed by such processes (e.g. young star clusters, DM halos) tend to a ρ∝R-3 density profile. We compare these predictions with observations, analytical fragmentation cascade models, semi-analytical models of gravito-turbulent fragmentation and detailed "full physics" hydrodynamical simulations. We find that these power-laws are good first order descriptions in all cases.

  3. The Long Term Effect on Children of Increasing the Length of Parents' Birth Related Leave

    DEFF Research Database (Denmark)

    Wurtz, Astrid

        The length of parents' total birth related leave was increased with almost 50% in 1984 in Denmark. The previous length of the Danish maternity leave was long, especially compared to e.g. the U.S. today. This paper investigates the long term effects on children of increasing length of birth...... and educational outcomes. A 100% sample Danish population born in May, June, July, and August 1983, 1984, and 1985 and a dataset with Danish PISA-2000 scores are used for the estimations. Preliminary results indicate there is no positive effect on children's cognitive outcomes from increasing parents' mandated...... related leave from 14 to 20 weeks. We use differences-in-differences regression discontinuity design to identify the causal effect of the leave reform and it estimated whether such a large increase in the mandated leave period has a large measurable and persistent effect on children's cognitive...

  4. Autism spectrum disorders: head circumference and body length at birth are both relative.

    Science.gov (United States)

    Grandgeorge, Marine; Lemonnier, Eric; Jallot, Nelle

    2013-09-01

    Although the body length and weight of an infant are related to head circumference, little research on ASDs has examined these factors. Our study compared the head circumferences of neonates who were later diagnosed with ASD with a control group. Additional comparisons on morphological disproportions at birth included the head circumference-to-height and head circumference-to-weight ratios. We recruited 422 children with ASD and 153 typically developing children. Head circumference, body length and weight at birth were collected and standardized as percentile scores according to gestational age and gender. Our results revealed that genuine macrocephaly was significantly higher in children with other pervasive developmental disorders compared with the control group. This difference was not observed with regard to genuine microcephaly. Relative macrocephaly and relative microcephaly were significantly more frequent in children with autism disorder compared with the control group with regard to body length. The differences in relative macrocephaly and microcephaly, as well as in other parameters, between diagnostic subgroups suggest that the presence of several neurological mechanisms plays a role in the later expression of different phenotypes. An increased head circumference-to-body length ratio in newborns may be a factor to follow that could be related to ASD. ©2013 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  5. Work-related exhaustion and telomere length: a population-based study.

    Directory of Open Access Journals (Sweden)

    Kirsi Ahola

    Full Text Available Psychological stress is suggested to accelerate the rate of biological aging. We investigated whether work-related exhaustion, an indicator of prolonged work stress, is associated with accelerated biological aging, as indicated by shorter leukocyte telomeres, that is, the DNA-protein complexes that cap chromosomal ends in cells.We used data from a representative sample of the Finnish working-age population, the Health 2000 Study. Our sample consisted of 2911 men and women aged 30-64. Work-related exhaustion was assessed using the Maslach Burnout Inventory--General Survey. We determined relative leukocyte telomere length using a quantitative real-time polymerase chain reaction (PCR -based method.After adjustment for age and sex, individuals with severe exhaustion had leukocyte telomeres on average 0.043 relative units shorter (standard error of the mean 0.016 than those with no exhaustion (p = 0.009. The association between exhaustion and relative telomere length remained significant after additional adjustment for marital and socioeconomic status, smoking, body mass index, and morbidities (adjusted difference 0.044 relative units, standard error of the mean 0.017, p = 0.008.These data suggest that work-related exhaustion is related to the acceleration of the rate of biological aging. This hypothesis awaits confirmation in a prospective study measuring changes in relative telomere length over time.

  6. Work-related exhaustion and telomere length: a population-based study.

    Science.gov (United States)

    Ahola, Kirsi; Sirén, Ilari; Kivimäki, Mika; Ripatti, Samuli; Aromaa, Arpo; Lönnqvist, Jouko; Hovatta, Iiris

    2012-01-01

    Psychological stress is suggested to accelerate the rate of biological aging. We investigated whether work-related exhaustion, an indicator of prolonged work stress, is associated with accelerated biological aging, as indicated by shorter leukocyte telomeres, that is, the DNA-protein complexes that cap chromosomal ends in cells. We used data from a representative sample of the Finnish working-age population, the Health 2000 Study. Our sample consisted of 2911 men and women aged 30-64. Work-related exhaustion was assessed using the Maslach Burnout Inventory--General Survey. We determined relative leukocyte telomere length using a quantitative real-time polymerase chain reaction (PCR) -based method. After adjustment for age and sex, individuals with severe exhaustion had leukocyte telomeres on average 0.043 relative units shorter (standard error of the mean 0.016) than those with no exhaustion (p = 0.009). The association between exhaustion and relative telomere length remained significant after additional adjustment for marital and socioeconomic status, smoking, body mass index, and morbidities (adjusted difference 0.044 relative units, standard error of the mean 0.017, p = 0.008). These data suggest that work-related exhaustion is related to the acceleration of the rate of biological aging. This hypothesis awaits confirmation in a prospective study measuring changes in relative telomere length over time.

  7. Sequential optimization of approximate inhibitory rules relative to the length, coverage and number of misclassifications

    KAUST Repository

    Alsolami, Fawaz

    2013-01-01

    This paper is devoted to the study of algorithms for sequential optimization of approximate inhibitory rules relative to the length, coverage and number of misclassifications. Theses algorithms are based on extensions of dynamic programming approach. The results of experiments for decision tables from UCI Machine Learning Repository are discussed. © 2013 Springer-Verlag.

  8. A Simple Derivation of Time Dilation and Length Contraction in Special Relativity

    Science.gov (United States)

    Behroozi, Fred

    2014-01-01

    Undergraduate physics majors typically begin their study of modern physics with special relativity. It is here that physics students first encounter the counterintuitive concepts of time dilation and length contraction. Unfortunately, the derivations of these results are often cloaked in several layers of analysis that render them rather…

  9. Length of Recovery From Sports-Related Concussions in Pediatric Patients Treated at Concussion Clinics.

    Science.gov (United States)

    Thomas, Donald J; Coxe, Kathryn; Li, Hongmei; Pommering, Thomas L; Young, Julie A; Smith, Gary A; Yang, Jingzhen

    2018-01-01

    We quantified the length of recovery time by week in a cohort of pediatric sports-related concussion patients treated at concussion clinics, and examined patient and injury characteristics associated with prolonged recovery. A retrospective, cohort design. Seven concussion clinics at a Midwest children's hospital. Patients aged 10 to 17 years with a diagnosed sports-related concussion presenting to the clinic within 30 days of injury. Length of recovery by week. Unadjusted and adjusted multinomial logistic regression analyses were used to model the effect of patient and injury characteristics on length of recovery by week. Median length of recovery was 17 days. Only 16.3% (299/1840) of patients recovered within one week, whereas 26.4% took longer than four weeks to recover. By 2 months postinjury, 6.7% of patients were still experiencing symptoms. Higher symptom scores at injury and initial visit were significantly associated with prolonged symptoms by week. Patients who presented to the clinic more than 2 weeks postinjury or who had 2 or more previous concussions showed increased risk for prolonged recovery. Females were at greater risk for prolonged recovery than males (odds ratio = 2.08, 95% confidence interval = 1.49-2.89). Age was not significantly associated with recovery length. High symptom scores at injury and initial visit, time to initial clinical presentation, presence of 2 or more previous concussions, and female sex are associated with prolonged concussion recovery. Further research should aim to establish objective measures of recovery, accounting for treatment received during the recovery. The median length of recovery is 17 days among pediatric sports-related concussion patients treated at concussion clinics. Only 16.3% of patients recovered within one week, whereas 26.4% took longer than 4 weeks to recover.

  10. Length-Displacement Scaling of Lunar Thrust Faults and the Formation of Uphill-Facing Scarps

    Science.gov (United States)

    Hiesinger, Harald; Roggon, Lars; Hetzel, Ralf; Clark, Jaclyn D.; Hampel, Andrea; van der Bogert, Carolyn H.

    2017-04-01

    Lobate scarps are straight to curvilinear positive-relief landforms that occur on all terrestrial bodies [e.g., 1-3]. They are the surface manifestation of thrust faults that cut through and offset the upper part of the crust. Fault scarps on planetary surfaces provide the opportunity to study the growth of faults under a wide range of environmental conditions (e.g., gravity, temperature, pore pressure) [4]. We studied four lunar thrust-fault scarps (Simpelius-1, Morozov (S1), Fowler, Racah X-1) ranging in length from 1.3 km to 15.4 km [5] and found that their maximum total displacements are linearly correlated with length over one order of magnitude. We propose that during the progressive accumulation of slip, lunar faults propagate laterally and increase in length. On the basis of our measurements, the ratio of maximum displacement, D, to fault length, L, ranges from 0.017 to 0.028 with a mean value of 0.023 (or 2.3%). This is an order of magnitude higher than the value of 0.1% derived by theoretical considerations [4], and about twice as large as the value of 0.012-0.013 estimated by [6,7]. Our results, in addition to recently published findings for other lunar scarps [2,8], indicate that the D/L ratios of lunar thrust faults are similar to those of faults on Mercury and Mars (e.g., 1, 9-11], and almost as high as the average D/L ratio of 3% for faults on Earth [16,23]. Three of the investigated thrust fault scarps (Simpelius-1, Morozov (S1), Fowler) are uphill-facing scarps generated by slip on faults that dip in the same direction as the local topography. Thrust faults with such a geometry are common ( 60% of 97 studied scarps) on the Moon [e.g., 2,5,7]. To test our hypothesis that the surface topography plays an important role in the formation of uphill-facing fault scarps by controlling the vertical load on a fault plane, we simulated thrust faulting and its relation to topography with two-dimensional finite-element models using the commercial code ABAQUS

  11. Manufacturing test of large scale hollow capsule and long length cladding in the large scale oxide dispersion strengthened (ODS) martensitic steel

    International Nuclear Information System (INIS)

    Narita, Takeshi; Ukai, Shigeharu; Kaito, Takeji; Ohtsuka, Satoshi; Fujiwara, Masayuki

    2004-04-01

    Mass production capability of oxide dispersion strengthened (ODS) martensitic steel cladding (9Cr) has being evaluated in the Phase II of the Feasibility Studies on Commercialized Fast Reactor Cycle System. The cost for manufacturing mother tube (raw materials powder production, mechanical alloying (MA) by ball mill, canning, hot extrusion, and machining) is a dominant factor in the total cost for manufacturing ODS ferritic steel cladding. In this study, the large-sale 9Cr-ODS martensitic steel mother tube which is made with a large-scale hollow capsule, and long length claddings were manufactured, and the applicability of these processes was evaluated. Following results were obtained in this study. (1) Manufacturing the large scale mother tube in the dimension of 32 mm OD, 21 mm ID, and 2 m length has been successfully carried out using large scale hollow capsule. This mother tube has a high degree of accuracy in size. (2) The chemical composition and the micro structure of the manufactured mother tube are similar to the existing mother tube manufactured by a small scale can. And the remarkable difference between the bottom and top sides in the manufactured mother tube has not been observed. (3) The long length cladding has been successfully manufactured from the large scale mother tube which was made using a large scale hollow capsule. (4) For reducing the manufacturing cost of the ODS steel claddings, manufacturing process of the mother tubes using a large scale hollow capsules is promising. (author)

  12. Hierarchical Self-Assembly of Peptide Amphiphiles: Form and Function at Multiple Length Scales

    Science.gov (United States)

    Zha, Runye Helen

    Hierarchical self-assembly, the organization of molecules into supramolecular structures of increasing size and complexity, is a potent tool for materials synthesis and requires understanding the connections of structure across multiple length scales. Herein, self-assembly of peptide amphiphiles (PAs) into nanoscopic and macroscopic materials is explored, and their anti-cancer applications are investigated. First, nanoscale assembly is examined in the context of an anti-angiogenic PA bearing the G-helix motif of maspin, a tumor suppressor protein. Assembly of this maspin-mimetic PA (MMPA) stabilizes the native G-helix conformation and improves binding to endothelial cells. Furthermore, PA nanostructures significantly increase cell adhesion to fibronectin as compared to G-helix peptide alone. Combined with its inhibitory effect on cell migration, MMPA nanostructures thus show anti-angiogenic activity on par with maspin protein in vitro and in vivo. Second, assembly of cationic PAs with hyaluronic acid (HA), an anionic polyelectrolyte, into macroscopic membranes is explored using PAs with identical formal charge but systematically varied self-assembly domains. Results suggest that membrane formation is dictated by the initial moments of component aggregation and is highly sensitive to PA molecular structure via nanoscale assembly. Specifically, PAs with beta-sheet forming residues are nanofibrous and have high surface charge density, leading to robust membranes with aligned-fiber microstructure. PAs without beta-sheet forming residues are nanospherical and have low surface charge density, leading to weak membranes with non-fibrous finger-like microstructure. Lastly, the principles of PA-HA membrane assembly are applied towards development of anti-cancer therapeutic biomaterials. Here, cytotoxic PAs bearing the epitope (KLAKLAKbeta)2 are co-assembled with non-bioactive cationic PA in order to achieve varying nanoscale morphology. These nanostructures are then

  13. The Pauli equation in scale relativity

    Energy Technology Data Exchange (ETDEWEB)

    Celerier, Marie-Noelle; Nottale, Laurent [LUTH, CNRS, Observatoire de Paris-Meudon, 5 place Jules Janssen, 92195 Meudon Cedex (France)

    2006-10-06

    In standard quantum mechanics, it is not possible to directly extend the Schroedinger equation to spinors, so the Pauli equation must be derived from the Dirac equation by taking its non-relativistic limit. Hence, it predicts the existence of an intrinsic magnetic moment for the electron and gives its correct value. In the scale relativity framework, the Schroedinger, Klein-Gordon and Dirac equations have been derived from first principles as geodesics equations of a non-differentiable and continuous spacetime. Since such a generalized geometry implies the occurrence of new discrete symmetry breakings, this has led us to write Dirac bi-spinors in the form of bi-quaternions (complex quaternions). In the present work, we show that, in scale relativity also, the correct Pauli equation can only be obtained from a non-relativistic limit of the relativistic geodesics equation (which, after integration, becomes the Dirac equation) and not from the non-relativistic formalism (that involves symmetry breakings in a fractal 3-space). The same degeneracy procedure, when it is applied to the bi-quaternionic 4-velocity used to derive the Dirac equation, naturally yields a Pauli-type quaternionic 3-velocity. It therefore corroborates the relevance of the scale relativity approach for the building from first principles of the quantum postulates and the quantum tools. This also reinforces the relativistic and fundamentally quantum nature of spin, which we attribute in scale relativity to the non-differentiability of the quantum spacetime geometry (and not only of the quantum space). We conclude by performing numerical simulations of spinor geodesics, that allow one to gain a physical geometric picture of the nature of spin.

  14. Intraspecific variation in sperm length is negatively related to sperm competition in passerine birds.

    Science.gov (United States)

    Kleven, Oddmund; Laskemoen, Terje; Fossøy, Frode; Robertson, Raleigh J; Lifjeld, Jan T

    2008-02-01

    Spermatozoa are among the most diversified cells in the animal kingdom, but the underlying evolutionary forces affecting intraspecific variation in sperm morphology are poorly understood. It has been hypothesized that sperm competition is a potent selection pressure on sperm variation within species. Here, we examine intraspecific variation in total sperm length of 22 wild passerine bird species (21 genera, 11 families) in relation to the risk of sperm competition, as expressed by the frequency of extrapair paternity and relative testis size. We demonstrate, by using phylogenetic comparative methods, that between-male variation in sperm length within species is closely and negatively linked to the risk of sperm competition. This relationship was even stronger when only considering species in which data on sperm length and extrapair paternity originated from the same populations. Intramale variation in sperm length within species was also negatively, although nonsignificantly, related to sperm competition risk. Our findings suggest that postcopulatory sexual selection is a powerful evolutionary force reducing the intraspecific phenotypic variation in sperm-size traits, potentially driving the diversification of sperm morphology across populations and species.

  15. Finite-fault scaling relations in Mexico

    Science.gov (United States)

    Rodríguez-Pérez, Quetzalcoatl; Ottemöller, Lars

    2013-06-01

    Earthquake source parameters are widely used for computing scaling laws. We estimated source parameters for earthquakes in the Gulf of California, and the Mexican subduction zone through teleseismic fault slip inversion. The scaling relations herein can provide useful information for studies focused on source characteristics and ground motions in Mexico. We derived source scaling relations to estimate fault dimensions, combined asperity area, ratio of combined asperity area to rupture area, maximum displacement, mean displacement, duration and seismic energy of subduction interplate earthquakes based on their moment magnitude. We do not developed scaling relationships for strike-slip events in the Gulf of California due to the reduced number of data, but compare source parameters. We analyzed differences in source parameters between the two types of earthquakes. Scaling relations were fitted with orthogonal regression and we analyzed the difference between our subduction zone relationships and previous ones. We determined 21 finite-fault slip distributions for earthquakes in the magnitude range of 6.5 authors based on different inversion methods to construct scaling relationships in a consistent manner. Within this study, we characterized heterogeneous slip models by determining source parameters on the asperities and on the background area, such as number of asperities, combined asperity area, stress drop on asperities, aspect ratio, strain and average stress drop. We found that the area of the asperities represented about 22 and 24 per cent of the total area for strike-slip, and reverse events respectively with two different criteria based on average slip and maximum displacement. Sensitivity tests were carried out to estimate the variability of slip patterns and source parameters by changing fault dimensions, subfault size and the number of stations. We observed robust slip solutions and reliable source parameter estimations resulting in robust scaling

  16. Studies on the growth of penaeid prawns: 1. Length-weight relation and condition factor under different levels of feeding

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, S.R.S.; Iyer, H.K.; Devi, C.B.L.; Kutty, M.K.

    Length-weight relation and earthworm feeding conditions under different levels for @iPenaeus indicus@@ and @iMetapenaeus dobsoni@@ were estimated. Length-weight exponent in both species was unaffected by the feeding levels and the consequent...

  17. Motion of nanoprobes in complex liquids within the framework of the length-scale dependent viscosity model.

    Science.gov (United States)

    Kalwarczyk, Tomasz; Sozanski, Krzysztof; Ochab-Marcinek, Anna; Szymanski, Jedrzej; Tabaka, Marcin; Hou, Sen; Holyst, Robert

    2015-09-01

    This paper deals with the recent phenomenological model of the motion of nanoscopic objects (colloidal particles, proteins, nanoparticles, molecules) in complex liquids. We analysed motion in polymer, micellar, colloidal and protein solutions and the cytoplasm of living cells using the length-scale dependent viscosity model. Viscosity monotonically approaches macroscopic viscosity as the size of the object increases and thus gives a single, coherent picture of motion at the nano and macro scale. The model includes interparticle interactions (solvent-solute), temperature and the internal structure of a complex liquid. The depletion layer ubiquitously occurring in complex liquids is also incorporated into the model. We also discuss the biological aspects of crowding in terms of the length-scale dependent viscosity model. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. A micromechanical approach of suffusion based on a length scale analysis of the grain detachment and grain transport processes.

    Science.gov (United States)

    Wautier, Antoine; Bonelli, Stéphane; Nicot, François

    2017-06-01

    Suffusion is the selective erosion of the finest particles of a soil subjected to an internal flow. Among the four types of internal erosion and piping identified today, suffusion is the least understood. Indeed, there is a lack of micromechanical approaches for identifying the critical microstructural parameters responsible for this process. Based on a discrete element modeling of non cohesive granular assemblies, specific micromechanical tools are developed in a unified framework to account for the two first steps of suffusion, namely the grain detachment and the grain transport processes. Thanks to the use of an enhanced force chain definition and autocorrelation functions the typical lengths scales associated with grain detachment are characterized. From the definition of transport paths based on a graph description of the pore space the typical lengths scales associated with grain transport are recovered. For a uniform grain size distribution, a separation of scales between these two processes exists for the finest particles of a soil

  19. Sub-pixel correlation length neutron imaging: Spatially resolved scattering information of microstructures on a macroscopic scale

    Science.gov (United States)

    Harti, Ralph P.; Strobl, Markus; Betz, Benedikt; Jefimovs, Konstantins; Kagias, Matias; Grünzweig, Christian

    2017-01-01

    Neutron imaging and scattering give data of significantly different nature and traditional methods leave a gap of accessible structure sizes at around 10 micrometers. Only in recent years overlap in the probed size ranges could be achieved by independent application of high resolution scattering and imaging methods, however without providing full structural information when microstructures vary on a macroscopic scale. In this study we show how quantitative neutron dark-field imaging with a novel experimental approach provides both sub-pixel resolution with respect to microscopic correlation lengths and imaging of macroscopic variations of the microstructure. Thus it provides combined information on multiple length scales. A dispersion of micrometer sized polystyrene colloids was chosen as a model system to study gravity induced crystallisation of microspheres on a macro scale, including the identification of ordered as well as unordered phases. Our results pave the way to study heterogeneous systems locally in a previously impossible manner. PMID:28303923

  20. A micromechanical approach of suffusion based on a length scale analysis of the grain detachment and grain transport processes.

    Directory of Open Access Journals (Sweden)

    Wautier Antoine

    2017-01-01

    Full Text Available Suffusion is the selective erosion of the finest particles of a soil subjected to an internal flow. Among the four types of internal erosion and piping identified today, suffusion is the least understood. Indeed, there is a lack of micromechanical approaches for identifying the critical microstructural parameters responsible for this process. Based on a discrete element modeling of non cohesive granular assemblies, specific micromechanical tools are developed in a unified framework to account for the two first steps of suffusion, namely the grain detachment and the grain transport processes. Thanks to the use of an enhanced force chain definition and autocorrelation functions the typical lengths scales associated with grain detachment are characterized. From the definition of transport paths based on a graph description of the pore space the typical lengths scales associated with grain transport are recovered. For a uniform grain size distribution, a separation of scales between these two processes exists for the finest particles of a soil

  1. [The presence of the os peroneum and relative metatarsal length - X-ray study].

    Science.gov (United States)

    Pávek, N; Žáková, I

    2015-01-01

    PURPOSE OF THE STUDY The os peroneum is a sesamoid bone found within the peroneus longus tendon and is present in the form of ossification on radiographs in 8-26% of the population. It is most likely the result of stress in the lateral side of the foot in connection with genetic factors. The factors affecting os peroneum development include anatomical changes, among others the length of the metatarsals especially because of the main tendon insertion on the first metatarsal bone. MATERIAL AND METHODS In the study, 768 standardised radiographs of feet of the Caucasian population, taken between 2006 and 2012 in the Vamed Mediterra hospital (Mostiště, Czech Republic), were investigated. The median age of the patients was 42 years, the range 18-75 years. The presence of an os peroneum was assessed and metatarsal length was measured by a modified method of Maestro. RESULTS The os peroneum was identified in 106 subjects (13.8%). Among the groups established according to the presence of os peroneum and its relation to the length of a metatarsal bone, the relationship with the first metatarsal (1+) was most frequent; it was seven-fold higher compared to the other variants. On the contrary, the variant 3+ was least frequent in the presence of the os peroneum. CONCLUSIONS The study presents a statistically significant relationship between the presence of the os peroneum and the length of the first metatarsal bone. Potentially, this is one of the causes of forefoot pain in relation to the os peroneum development and anatomical connections in this area. Key words: os peroneum, relative metatarsal length.

  2. Characterizing the reinforcement mechanisms in multiwall nanotube/polycarbonate composites across different length and time scales

    Science.gov (United States)

    Duncan, Renee Kelly

    The enthusiasm and interest in the potential properties of nanotube (NT)/polymer composites are based on several factors, including the potential for unsurpassed enhancements in mechanical properties together with electrical, thermal and optical properties. Using multiwall nanotubes (MWNTs) grown to a long aspect ratio, the study found that fragmentation tests can be completed in a similar manner to traditional fiber composites. It was found that the fragmentation length does not depend on the angle of the nanotube to the loading direction hence the ISS does not change with the orientation angle of the nanotube in the composite. A critical aspect ratio of 100 and 300 for untreated nanotubes (ARNT) and treated nanotubes (EPNT), respectively was also measured. For nanotubes that are well dispersed in the polycarbonate, it was observed at a critical angle of 60° that there was a change in failure mechanism from pullout to fracture of the nanotubes due to bending shear. Because the tensile strength of a MWNT is unknown a cumulative distribution was used to characterize the relative interfacial shear strength as a function of nanotube chemical modification. The second goal of this thesis is to use Dynamic Mechanical Thermal Analysis (DMTA) with controlled aspect ratios of multiwall nanotubes (MWNT) to isolate and quantify the effects of the interfacial region on modulus enhancements in nanotube-reinforced composites. One major finding of this study was that the shortest aspect ratio showed a significantly broadened relaxation spectrum than the longer aspect ratio nanotubes, despite the longer aspect ratio nanotubes being more percolated at the given weight percent. There is also a direct correlation between the free space parameter of the short aspect ratio nantoubes network and broadening of the relaxation spectrum, concluded to be a result of increased interaction of the interfacial polymer. The study found agreement with the premise that at a constant filler weight

  3. Dynamics of an elastic sphere containing a thin creeping region and immersed in an acoustic region for similar viscous-elastic and acoustic time- and length-scales

    Science.gov (United States)

    Gat, Amir; Friedman, Yonathan

    2017-11-01

    The characteristic time of low-Reynolds number fluid-structure interaction scales linearly with the ratio of fluid viscosity to solid Young's modulus. For sufficiently large values of Young's modulus, both time- and length-scales of the viscous-elastic dynamics may be similar to acoustic time- and length-scales. However, the requirement of dominant viscous effects limits the validity of such regimes to micro-configurations. We here study the dynamics of an acoustic plane wave impinging on the surface of a layered sphere, immersed within an inviscid fluid, and composed of an inner elastic sphere, a creeping fluid layer and an external elastic shell. We focus on configurations with similar viscous-elastic and acoustic time- and length-scales, where the viscous-elastic speed of interaction between the creeping layer and the elastic regions is similar to the speed of sound. By expanding the linearized spherical Reynolds equation into the relevant spectral series solution for the hyperbolic elastic regions, a global stiffness matrix of the layered elastic sphere was obtained. This work relates viscous-elastic dynamics to acoustic scattering and may pave the way to the design of novel meta-materials with unique acoustic properties. ISF 818/13.

  4. Channel length scaling and the impact of metal gate work function ...

    Indian Academy of Sciences (India)

    port and experimental data extracted in DG-MOSFETs devices. At these channel length limits, the susceptibility of the transistor to short-channel effects (SCE) is monitored in several ways such as threshold voltage (VTH), subthreshold voltage slope (S), leakage current (IOFF) and the drain-induced barrier lowering (DIBL).

  5. Independent and collective roles of surface structures at different length scales on pool boiling heat transfer

    Science.gov (United States)

    Li, Calvin H.; Rioux, Russell P.

    2016-01-01

    Spherical Cu nanocavity surfaces are synthesized to examine the individual role of contact angles in connecting lateral Rayleigh-Taylor wavelength to vertical Kevin-Helmholtz wavelength on hydrodynamic instability for the onset of pool boiling Critical Heat Flux (CHF). Solid and porous Cu pillar surfaces are sintered to investigate the individual role of pillar structure pitch at millimeter scale, named as module wavelength, on hydrodynamic instability at CHF. Last, spherical Cu nanocavities are coated on the porous Cu pillars to create a multiscale Cu structure, which is studied to examine the collective role and relative significance of contact angles and module wavelength on hydrodynamic instability at CHF, and the results indicate that module wavelength plays the dominant role on hydrodynamic instability at CHF when the height of surface structures is equal or above ¼ Kelvin-Helmholtz wavelength. Pool boiling Heat Transfer Coefficient (HTC) enhancements on spherical Cu nanocavity surfaces, solid and porous Cu pillar surfaces, and the integrated multiscale structure have been investigated, too. The experimental results reveal that the nanostructures and porous pillar structures can be combined together to achieve even higher enhancement of HTC than that of individual structures. PMID:27841322

  6. Parameterizing amylose chain-length distributions for biosynthesis-structure-property relations.

    Science.gov (United States)

    Nada, Sharif S; Zou, Wei; Li, Changfeng; Gilbert, Robert G

    2017-11-01

    Amylose, one of the components of starch, is a glucose polymer consisting largely of long, linear chains with a few long-chain branch points. The chain-length (molecular weight) distribution (CLD) of the component chains of amylose can provide information on amylose biosynthesis-structure-property relations, as has been done previously by fitting amylopectin CLDs to a model with physically meaningful parameters. Due to the presence of long chains, the CLD of amylose can currently best be obtained by size-exclusion chromatography, a technique that suffers from band-broadening effects which alter the observed distribution. The features of the multiple regions present in amylose chain-length distributions are also difficult to resolve, an issue that combines with band broadening to compound the difficulty of analysis and subsequent parameterization of the structural characteristics of amylose. A new method is presented to fit these distributions with biologically meaningful parameters in a way that accounts for band broadening. This is achieved by assuming that band broadening takes the form of a simple Gaussian over a relatively small region and that chain stoppage is a random process independent of the length of the substrate chain over the same region; these assumptions are relatively weak and expected to be frequently applicable. The method provides inbuilt consistency tests for its applicability to a given data set and, in cases where it is applicable, allows for the first nonempirical parameterization of amylose biosynthesis-structure-property relations from CLDs by using parameters directly linked to the activities of the enzymes responsible for chain growth and chain stoppage. Graphical abstract Model calculation illustrating the method described and showing the division between the three characteristic regions of a typical amylose chain-length distribution.

  7. Three-dimensional anatomy of equine incisors: tooth length, enamel cover and age related changes.

    Science.gov (United States)

    Schrock, Patricia; Lüpke, Matthias; Seifert, Hermann; Staszyk, Carsten

    2013-12-09

    Equine incisors are subjected to continuous occlusal wear causing multiple, age related changes of the extragingival crown. It is assumed that the occlusal wear is compensated by continued tooth elongation at the apical ends of the teeth. In this study, μCT-datasets offered the opportunity to analyze the three-dimensional appearance of the extra- and intraalveolar parts of the enamel containing dental crown as well as of the enamel-free dental root. Multiple morphometric measurements elucidated age related, morphological changes within the intraalveolar part of the incisors. Equine incisors possess a unique enamel cover displaying large indentations on the mesial and distal sides. After eruption tooth elongation at the apical end outbalances occlusal wear for two to four years resulting in increasing incisor length in this period of time. Remarkably, this maximum length is maintained for about ten years, up to a tooth age of 13 to 15 years post eruption. Variances in the total length of individual teeth are related to different Triadan positions (central-, middle- and corner incisors) as well as to the upper and lower arcades. Equine incisors are able to fully compensate occlusal wear for a limited period of time. However, after this ability ceases, it is expected that a diminished intraalveolar tooth length will cause massive changes in periodontal biomechanics. The time point of these morphodynamic and biomechanical changes (13 to 15 years post eruption) occurs in coincidence with the onset of a recently described destructive disease of equine incisor (equine odontoclastic tooth resorption and hypercementosis) in aged horses. However, further biomechanical, cell biological and microbiological investigations are needed to elucidate a correlation between age related changes of incisor morphology and this disease.

  8. Three-dimensional anatomy of equine incisors: tooth length, enamel cover and age related changes

    Science.gov (United States)

    2013-01-01

    Background Equine incisors are subjected to continuous occlusal wear causing multiple, age related changes of the extragingival crown. It is assumed that the occlusal wear is compensated by continued tooth elongation at the apical ends of the teeth. In this study, μCT-datasets offered the opportunity to analyze the three-dimensional appearance of the extra- and intraalveolar parts of the enamel containing dental crown as well as of the enamel-free dental root. Multiple morphometric measurements elucidated age related, morphological changes within the intraalveolar part of the incisors. Results Equine incisors possess a unique enamel cover displaying large indentations on the mesial and distal sides. After eruption tooth elongation at the apical end outbalances occlusal wear for two to four years resulting in increasing incisor length in this period of time. Remarkably, this maximum length is maintained for about ten years, up to a tooth age of 13 to 15 years post eruption. Variances in the total length of individual teeth are related to different Triadan positions (central-, middle- and corner incisors) as well as to the upper and lower arcades. Conclusion Equine incisors are able to fully compensate occlusal wear for a limited period of time. However, after this ability ceases, it is expected that a diminished intraalveolar tooth length will cause massive changes in periodontal biomechanics. The time point of these morphodynamic and biomechanical changes (13 to 15 years post eruption) occurs in coincidence with the onset of a recently described destructive disease of equine incisor (equine odontoclastic tooth resorption and hypercementosis) in aged horses. However, further biomechanical, cell biological and microbiological investigations are needed to elucidate a correlation between age related changes of incisor morphology and this disease. PMID:24321365

  9. Length of unemployment and health-related outcomes: a life-course analysis.

    Science.gov (United States)

    Janlert, Urban; Winefield, Anthony H; Hammarström, Anne

    2015-08-01

    Most previous studies on the effects of length of unemployment on health have focused on the duration of continuous spells of unemployment rather than on the cumulative length of intermittent spells. This study analysed the relationship between the cumulative length of intermittent spells of unemployment and different health-related outcomes using data from a longitudinal study of school leavers. All pupils who completed compulsory schooling in 1981 in a medium-sized town in northern Sweden (N = 1083) were followed for 14 years with repeated questionnaires including questions about unemployment, health and health behaviour. Men tended to react with a steady state or a levelling off of health symptoms with increased unemployment, whereas women showed deteriorating health symptoms. For health behaviour the reverse occurred. Women's health behaviour was less connected with increased unemployment while men's health behaviour tended to deteriorate. Cumulative length of unemployment is correlated with deteriorated health and health behaviour. Long-term unemployment, even as a result of cumulated shorter employment spells over a number of years should be an urgent target for policy makers. © The Author 2014. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

  10. A multi-resolution analysis of lidar-DTMs to identify geomorphic processes from characteristic topographic length scales

    Science.gov (United States)

    Sangireddy, H.; Passalacqua, P.; Stark, C. P.

    2013-12-01

    Characteristic length scales are often present in topography, and they reflect the driving geomorphic processes. The wide availability of high resolution lidar Digital Terrain Models (DTMs) allows us to measure such characteristic scales, but new methods of topographic analysis are needed in order to do so. Here, we explore how transitions in probability distributions (pdfs) of topographic variables such as (log(area/slope)), defined as topoindex by Beven and Kirkby[1979], can be measured by Multi-Resolution Analysis (MRA) of lidar DTMs [Stark and Stark, 2001; Sangireddy et al.,2012] and used to infer dominant geomorphic processes such as non-linear diffusion and critical shear. We show this correlation between dominant geomorphic processes to characteristic length scales by comparing results from a landscape evolution model to natural landscapes. The landscape evolution model MARSSIM Howard[1994] includes components for modeling rock weathering, mass wasting by non-linear creep, detachment-limited channel erosion, and bedload sediment transport. We use MARSSIM to simulate steady state landscapes for a range of hillslope diffusivity and critical shear stresses. Using the MRA approach, we estimate modal values and inter-quartile ranges of slope, curvature, and topoindex as a function of resolution. We also construct pdfs at each resolution and identify and extract characteristic scale breaks. Following the approach of Tucker et al.,[2001], we measure the average length to channel from ridges, within the GeoNet framework developed by Passalacqua et al.,[2010] and compute pdfs for hillslope lengths at each scale defined in the MRA. We compare the hillslope diffusivity used in MARSSIM against inter-quartile ranges of topoindex and hillslope length scales, and observe power law relationships between the compared variables for simulated landscapes at steady state. We plot similar measures for natural landscapes and are able to qualitatively infer the dominant geomorphic

  11. Length-scales of chemical and isotopic heterogeneity in the mantle section of the Shetland Ophiolite Complex, Scotland

    Science.gov (United States)

    O'Driscoll, B.; Walker, R. J.; Clay, P. L.; Day, J. M. D.; Ash, R. D.; Daly, J. S.

    2018-04-01

    Kilometre to sub-metre scale heterogeneities have been inferred in the oceanic mantle based on sampling of both ophiolites and abyssal peridotites. The ∼492 Ma Shetland Ophiolite Complex (SOC) contains a well-preserved mantle section that is dominated by harzburgite (∼70 vol.%) previously reported to have variable major and trace element compositions, yet dominantly chondritic initial 187Os/188Os compositions. To assess the preservation of compositional heterogeneities at sub-metre length-scales in the oceanic mantle, a ∼45 m2 area of the SOC mantle section was mapped and sampled in detail. Harzburgites, dunites and a pyroxenite from this area were analysed for lithophile and highly-siderophile element (HSE) abundances, as well as for 187Os/188Os ratios. Lithophile element data for most rocks are characteristic of supra-subduction zone (SSZ) metasomatic processes. Two dunites have moderately fractionated HSE patterns and suprachondritic γOs(492 Ma) values (+5.1 and +7.5) that are also typical of ophiolitic dunites generated by SSZ melt-rock interactions. By contrast, six harzburgites and four dunites have approximately chondritic-relative abundances of Os, Ir and Ru, and γOs(492 Ma) values ranging only from -0.6 to +2.7; characteristics that imply no significant influence during SSZ processes. Two harzburgites are also characterised by significantly less radiogenic γOs(492 Ma) values (-3.5 and -4), and yield Mesoproterozoic time of Re depletion (TRD) model ages. The range of Os isotope compositions in the studied area is comparable to the range reported for a suite of samples representative of the entire SOC mantle section, and approaches the total isotopic variation of the oceanic mantle, as observed in abyssal peridotites. Mechanisms by which this heterogeneity can be formed and preserved involve inefficient and temporally distinct melt extraction events and strong localised channelling of these melts.

  12. Modelling of multiple short-length-scale stall cells in an axial compressor using evolved GMDH neural networks

    International Nuclear Information System (INIS)

    Amanifard, N.; Nariman-Zadeh, N.; Farahani, M.H.; Khalkhali, A.

    2008-01-01

    Over the past 15 years there have been several research efforts to capture the stall inception nature in axial flow compressors. However previous analytical models could not explain the formation of short-length-scale stall cells. This paper provides a new model based on evolved GMDH neural network for transient evolution of multiple short-length-scale stall cells in an axial compressor. Genetic Algorithms (GAs) are also employed for optimal design of connectivity configuration of such GMDH-type neural networks. In this way, low-pass filter (LPF) pressure trace near the rotor leading edge is modelled with respect to the variation of pressure coefficient, flow rate coefficient, and number of rotor rotations which are defined as inputs

  13. Spectral properties and scaling relations in off diagonally disordered chains

    International Nuclear Information System (INIS)

    Ure, J.E.; Majlis, N.

    1987-07-01

    We obtain the localization length L as a function of the energy E and the disorder width W for an off-diagonally disordered chain. This is done performing numerical simulations involving the continued fraction representations of the transfer matrix. The scaling relation L=W s is obtained with values of the exponent s in agreement with calculations of other authors. We also obtain the relation L ∼ |E| v for E → 0, and use it in the Herbert-Spencer-Thouless formula for L to describe the singularity of the density of states near E=0. We show that the slightest diagonal disorder obliterates this singularity. A practical method is presented to calculate the Green function by exploiting its continued fraction expansion. (author). 20 refs, 4 figs

  14. Correlation Lengths for Estimating the Large-Scale Carbon and Heat Content of the Southern Ocean

    Science.gov (United States)

    Mazloff, M. R.; Cornuelle, B. D.; Gille, S. T.; Verdy, A.

    2018-02-01

    The spatial correlation scales of oceanic dissolved inorganic carbon, heat content, and carbon and heat exchanges with the atmosphere are estimated from a realistic numerical simulation of the Southern Ocean. Biases in the model are assessed by comparing the simulated sea surface height and temperature scales to those derived from optimally interpolated satellite measurements. While these products do not resolve all ocean scales, they are representative of the climate scale variability we aim to estimate. Results show that constraining the carbon and heat inventory between 35°S and 70°S on time-scales longer than 90 days requires approximately 100 optimally spaced measurement platforms: approximately one platform every 20° longitude by 6° latitude. Carbon flux has slightly longer zonal scales, and requires a coverage of approximately 30° by 6°. Heat flux has much longer scales, and thus a platform distribution of approximately 90° by 10° would be sufficient. Fluxes, however, have significant subseasonal variability. For all fields, and especially fluxes, sustained measurements in time are required to prevent aliasing of the eddy signals into the longer climate scale signals. Our results imply a minimum of 100 biogeochemical-Argo floats are required to monitor the Southern Ocean carbon and heat content and air-sea exchanges on time-scales longer than 90 days. However, an estimate of formal mapping error using the current Argo array implies that in practice even an array of 600 floats (a nominal float density of about 1 every 7° longitude by 3° latitude) will result in nonnegligible uncertainty in estimating climate signals.

  15. Calibration of Eringen's small length scale coefficient for initially stressed vibrating nonlocal Euler beams based on microstructured beam model

    International Nuclear Information System (INIS)

    Wang, C M; Zhang, Z; Challamel, N; Duan, W H

    2013-01-01

    In this paper, we calibrate Eringen's small length scale coefficient e 0 for an initially stressed vibrating nonlocal Euler beam via a microstructured beam modelled by some repetitive cells comprising finite rigid segments and elastic rotational springs. By adopting the pseudo-differential operator and Padé's approximation, an analytical solution for the vibration frequency in terms of initial stress may be developed for the microstructured beam model. When comparing this analytical solution with the established exact vibration solution from the nonlocal beam theory, one finds that the calibrated Eringen's small length scale coefficient e 0 is given by e 0 = √(1/6)-(1/12)(σ 0 /σ-breve m ) where σ 0 is the initial stress and σ-breve m is the mth mode buckling stress of the corresponding local Euler beam. It is shown that e 0 varies with respect to the initial axial stress, from 1/√(12)∼0.289 at the buckling compressive stress to 1/√6∼0.408 when the axial stress is zero and it monotonically increases with increasing initial tensile stress. The small length scale coefficient e 0 , however, does not depend on the vibration/buckling mode considered. (paper)

  16. Evolution of deformation heterogeneity at multiple length scales in a strongly textured zinc layer on galvanized steel

    International Nuclear Information System (INIS)

    Ghosh, A; Gurao, N P

    2015-01-01

    The evolution of heterogeneity of plastic deformation in a zinc layer has been probed at multiple length scales using a battery of characterization tools like X-ray diffraction, electron back scatter diffraction (EBSD) and digital image correlation. The experimental results indicate that plastic deformation is heterogeneous at different length scales and the value of micro, meso and macro strain by different characterization techniques shows a different value. The value of strain determined at the meso and micro length scale from EBSD and X-ray diffraction was negligible, however, the macro-strain as determined from X-ray peak shift was significant. EBSD results showed evidence of profuse {101-bar2} <101-bar1> contraction twinning in the zinc layer with higher intragranular misorientation in the twin compared to the matrix. It is therefore, inferred that the evolution of higher intergranular (between matrix and twin) strain due to prolific contraction twinning contributes to the failure of zinc layer on galvanized steel. (paper)

  17. Postsacral vertebral morphology in relation to tail length among primates and other mammals.

    Science.gov (United States)

    Russo, Gabrielle A

    2015-02-01

    Tail reduction/loss independently evolved in a number of mammalian lineages, including hominoid primates. One prerequisite to appropriately contextualizing its occurrence and understanding its significance is the ability to track evolutionary changes in tail length throughout the fossil record. However, to date, the bony correlates of tail length variation among living taxa have not been comprehensively examined. This study quantifies postsacral vertebral morphology among living primates and other mammals known to differ in relative tail length (RTL). Linear and angular measurements with known biomechanical significance were collected on the first, mid-, and transition proximal postsacral vertebrae, and their relationship with RTL was assessed using phylogenetic generalized least-squares regression methods. Compared to shorter-tailed primates, longer-tailed primates possess a greater number of postsacral vertebral features associated with increased proximal tail flexibility (e.g., craniocaudally longer vertebral bodies), increased intervertebral body joint range of motion (e.g., more circularly shaped cranial articular surfaces), and increased leverage of tail musculature (e.g., longer spinous processes). These observations are corroborated by the comparative mammalian sample, which shows that distantly related short-tailed (e.g., Phascolarctos, Lynx) and long-tailed (e.g., Dendrolagus, Acinonyx) nonprimate mammals morphologically converge with short-tailed (e.g., Macaca tonkeana) and long-tailed (e.g., Macaca fascicularis) primates, respectively. Multivariate models demonstrate that the variables examined account for 70% (all mammals) to 94% (only primates) of the variance in RTL. Results of this study may be used to infer the tail lengths of extinct primates and other mammals, thereby improving our understanding about the evolution of tail reduction/loss. © 2014 Wiley Periodicals, Inc.

  18. CHANG-ES. IX. Radio scale heights and scale lengths of a consistent sample of 13 spiral galaxies seen edge-on and their correlations

    Science.gov (United States)

    Krause, Marita; Irwin, Judith; Wiegert, Theresa; Miskolczi, Arpad; Damas-Segovia, Ancor; Beck, Rainer; Li, Jiang-Tao; Heald, George; Müller, Peter; Stein, Yelena; Rand, Richard J.; Heesen, Volker; Walterbos, Rene A. M.; Dettmar, Ralf-Jürgen; Vargas, Carlos J.; English, Jayanne; Murphy, Eric J.

    2018-03-01

    Aim. The vertical halo scale height is a crucial parameter to understand the transport of cosmic-ray electrons (CRE) and their energy loss mechanisms in spiral galaxies. Until now, the radio scale height could only be determined for a few edge-on galaxies because of missing sensitivity at high resolution. Methods: We developed a sophisticated method for the scale height determination of edge-on galaxies. With this we determined the scale heights and radial scale lengths for a sample of 13 galaxies from the CHANG-ES radio continuum survey in two frequency bands. Results: The sample average values for the radio scale heights of the halo are 1.1 ± 0.3 kpc in C-band and 1.4 ± 0.7 kpc in L-band. From the frequency dependence analysis of the halo scale heights we found that the wind velocities (estimated using the adiabatic loss time) are above the escape velocity. We found that the halo scale heights increase linearly with the radio diameters. In order to exclude the diameter dependence, we defined a normalized scale height h˜ which is quite similar for all sample galaxies at both frequency bands and does not depend on the star formation rate or the magnetic field strength. However, h˜ shows a tight anticorrelation with the mass surface density. Conclusions: The sample galaxies with smaller scale lengths are more spherical in the radio emission, while those with larger scale lengths are flatter. The radio scale height depends mainly on the radio diameter of the galaxy. The sample galaxies are consistent with an escape-dominated radio halo with convective cosmic ray propagation, indicating that galactic winds are a widespread phenomenon in spiral galaxies. While a higher star formation rate or star formation surface density does not lead to a higher wind velocity, we found for the first time observational evidence of a gravitational deceleration of CRE outflow, e.g. a lowering of the wind velocity from the galactic disk.

  19. Long-gauge length embedded fiber optic ultrasonic sensor for large-scale concrete structures

    Science.gov (United States)

    Yuan, Libo; Zhou, Limin; Jin, Wei

    2004-02-01

    A fiber optic ultrasonic sensor based on Fizeau interferometer has been developed and demonstrated. A helium-neon laser light source with wavelength 0.6328 μm is used in our experiment. A special feature is its Fizeau configuration, which enables one to eliminate much undesirable noise by combining both the reference arm and the sensing arm within the same length of fiber. The dynamic response model of photo-elastic effect of ultrasonic wave and optical fiber is established. The fiber optic ultrasonic sensor experimental results are obtained and compared with the convenient PZT transducer.

  20. Length-scale and strain rate-dependent mechanism of defect formation and fracture in carbon nanotubes under tensile loading

    Science.gov (United States)

    Javvaji, Brahmanandam; Raha, S.; Mahapatra, D. Roy

    2017-02-01

    Electromagnetic and thermo-mechanical forces play a major role in nanotube-based materials and devices. Under high-energy electron transport or high current densities, carbon nanotubes fail via sequential fracture. The failure sequence is governed by certain length scale and flow of current. We report a unified phenomenological model derived from molecular dynamic simulation data, which successfully captures the important physics of the complex failure process. Length-scale and strain rate-dependent defect nucleation, growth, and fracture in single-walled carbon nanotubes with diameters in the range of 0.47 to 2.03 nm and length which is about 6.17 to 26.45 nm are simulated. Nanotubes with long length and small diameter show brittle fracture, while those with short length and large diameter show transition from ductile to brittle fracture. In short nanotubes with small diameters, we observe several structural transitions like Stone-Wales defect initiation, its propagation to larger void nucleation, formation of multiple chains of atoms, conversion to monatomic chain of atoms, and finally complete fracture of the carbon nanotube. Hybridization state of carbon-carbon bonds near the end cap evolves, leading to the formation of monatomic chain in short nanotubes with small diameter. Transition from ductile to brittle fracture is also observed when strain rate exceeds a critical value. A generalized analytical model of failure is established, which correlates the defect energy during the formation of atomic chain with aspect ratio of the nanotube and strain rate. Variation in the mechanical properties such as elastic modulus, tensile strength, and fracture strain with the size and strain rate shows important implications in mitigating force fields and ways to enhance the life of electronic devices and nanomaterial conversion via fracture in manufacturing.

  1. Length-scale and strain rate-dependent mechanism of defect formation and fracture in carbon nanotubes under tensile loading

    Energy Technology Data Exchange (ETDEWEB)

    Javvaji, Brahmanandam [Indian Institute of Science, Department of Aerospace Engineering (India); Raha, S. [Indian Institute of Science, Department of Computational and Data Sciences (India); Mahapatra, D. Roy, E-mail: droymahapatra@aero.iisc.ernet.in [Indian Institute of Science, Department of Aerospace Engineering (India)

    2017-02-15

    Electromagnetic and thermo-mechanical forces play a major role in nanotube-based materials and devices. Under high-energy electron transport or high current densities, carbon nanotubes fail via sequential fracture. The failure sequence is governed by certain length scale and flow of current. We report a unified phenomenological model derived from molecular dynamic simulation data, which successfully captures the important physics of the complex failure process. Length-scale and strain rate-dependent defect nucleation, growth, and fracture in single-walled carbon nanotubes with diameters in the range of 0.47 to 2.03 nm and length which is about 6.17 to 26.45 nm are simulated. Nanotubes with long length and small diameter show brittle fracture, while those with short length and large diameter show transition from ductile to brittle fracture. In short nanotubes with small diameters, we observe several structural transitions like Stone-Wales defect initiation, its propagation to larger void nucleation, formation of multiple chains of atoms, conversion to monatomic chain of atoms, and finally complete fracture of the carbon nanotube. Hybridization state of carbon-carbon bonds near the end cap evolves, leading to the formation of monatomic chain in short nanotubes with small diameter. Transition from ductile to brittle fracture is also observed when strain rate exceeds a critical value. A generalized analytical model of failure is established, which correlates the defect energy during the formation of atomic chain with aspect ratio of the nanotube and strain rate. Variation in the mechanical properties such as elastic modulus, tensile strength, and fracture strain with the size and strain rate shows important implications in mitigating force fields and ways to enhance the life of electronic devices and nanomaterial conversion via fracture in manufacturing.

  2. High phobic anxiety is related to lower leukocyte telomere length in women.

    Directory of Open Access Journals (Sweden)

    Olivia I Okereke

    Full Text Available Chronic psychological distress has been linked to shorter telomeres, an indication of accelerated aging. Yet, little is known about relations of anxiety to telomeres. We examined whether a typically chronic form of anxiety--phobic anxiety--is related to telomere length.Relative telomere lengths (RTLs in peripheral blood leukocytes were measured by quantitative real-time polymerase chain reaction among 5,243 women (aged 42-69 years who: were participants in the Nurses' Health Study; were controls in prior case-control studies of telomeres and disease, or randomly selected healthy participants in a cognitive function sub-study; had completed the Crown-Crisp phobic index proximal to blood collection. Adjusted least-squares mean RTLs (z-scores were calculated across phobic categories. Higher phobic anxiety was generally associated with lower RTLs (age-adjusted p-trend = 0.09; this association was similar after adjustment for confounders--paternal age-at-birth, smoking, body mass index (BMI and physical activity (p-trend = 0.15. Notably, a threshold was identified. Among women with Crown-Crisp<6 points, the multivariable-adjusted least-squares mean RTL z-score = 0.02 standard units; however, among the most phobic women (Crown-Crisp ≥ 6, the multivariable-adjusted least-squares mean RTL z-score = -0.09 standard units (mean difference = -0.10 standard units; p = 0.02. The magnitude of this difference was comparable to that for women 6 years apart in age. Finally, effect modification by BMI, smoking and paternal age was observed: associations were stronger among highly phobic women with BMI ≥ 25 kg/m(2, without smoking history, or born to fathers aged ≥ 40 years.In this large, cross-sectional study high phobic anxiety was associated with shorter telomeres. These results point toward prospective investigations relating anxiety to telomere length change.

  3. On the performance of a generic length scale turbulence model within an adaptive finite element ocean model

    Science.gov (United States)

    Hill, Jon; Piggott, M. D.; Ham, David A.; Popova, E. E.; Srokosz, M. A.

    2012-10-01

    Research into the use of unstructured mesh methods for ocean modelling has been growing steadily in the last few years. One advantage of using unstructured meshes is that one can concentrate resolution where it is needed. In addition, dynamic adaptive mesh optimisation (DAMO) strategies allow resolution to be concentrated when this is required. Despite the advantage that DAMO gives in terms of improving the spatial resolution where and when required, small-scale turbulence in the oceans still requires parameterisation. A two-equation, generic length scale (GLS) turbulence model (one equation for turbulent kinetic energy and another for a generic turbulence length-scale quantity) adds this parameterisation and can be used in conjunction with adaptive mesh techniques. In this paper, an implementation of the GLS turbulence parameterisation is detailed in a non-hydrostatic, finite-element, unstructured mesh ocean model, Fluidity-ICOM. The implementation is validated by comparing to both a laboratory-scale experiment and real-world observations, on both fixed and adaptive meshes. The model performs well, matching laboratory and observed data, with resolution being adjusted as necessary by DAMO. Flexibility in the prognostic fields used to construct the error metric used in DAMO is required to ensure best performance. Moreover, the adaptive mesh models perform as well as fixed mesh models in terms of root mean square error to observation or theoretical mixed layer depths, but uses fewer elements and hence has a reduced computational cost.

  4. Introduction of the Abbreviated Westmead Post-Traumatic Amnesia Scale and Impact on Length of Stay

    NARCIS (Netherlands)

    Watson, C. E.; Clous, E. A.; Jaeger, M.; D'Amours, S. K.

    2017-01-01

    Mild traumatic brain injury is a common presentation to Emergency Departments. Early identification of patients with cognitive deficits and provision of discharge advice are important. The Abbreviated Westmead Post-traumatic Amnesia Scale provides an early and efficient assessment of post-traumatic

  5. An ancient relation between units of length and volume based on a sphere.

    Directory of Open Access Journals (Sweden)

    Elena Zapassky

    Full Text Available The modern metric system defines units of volume based on the cube. We propose that the ancient Egyptian system of measuring capacity employed a similar concept, but used the sphere instead. When considered in ancient Egyptian units, the volume of a sphere, whose circumference is one royal cubit, equals half a hekat. Using the measurements of large sets of ancient containers as a database, the article demonstrates that this formula was characteristic of Egyptian and Egyptian-related pottery vessels but not of the ceramics of Mesopotamia, which had a different system of measuring length and volume units.

  6. Membrane undulations in a structured fluid: Universal dynamics at intermediate length and time scales.

    Science.gov (United States)

    Granek, Rony; Diamant, Haim

    2018-01-05

    The dynamics of membrane undulations inside a viscous solvent is governed by distinctive, anomalous, power laws. Inside a viscoelastic continuous medium these universal behaviors are modified by the specific bulk viscoelastic spectrum. Yet, in structured fluids the continuum limit is reached only beyond a characteristic correlation length. We study the crossover to this asymptotic bulk dynamics. The analysis relies on a recent generalization of the hydrodynamic interaction in structured fluids, which shows a slow spatial decay of the interaction toward the bulk limit. For membranes which are weakly coupled to the structured medium we find a wide crossover regime characterized by different, universal, dynamic power laws. We discuss various systems for which this behavior is relevant, and delineate the time regime over which it may be observed.

  7. Reduced 3d modeling on injection schemes for laser wakefield acceleration at plasma scale lengths

    Science.gov (United States)

    Helm, Anton; Vieira, Jorge; Silva, Luis; Fonseca, Ricardo

    2017-10-01

    Current modelling techniques for laser wakefield acceleration (LWFA) are based on particle-in-cell (PIC) codes which are computationally demanding. In PIC simulations the laser wavelength λ0, in μm-range, has to be resolved over the acceleration lengths in meter-range. A promising approach is the ponderomotive guiding center solver (PGC) by only considering the laser envelope for laser pulse propagation. Therefore only the plasma skin depth λp has to be resolved, leading to speedups of (λp /λ0) 2. This allows to perform a wide-range of parameter studies and use it for λ0 Tecnologia (FCT), Portugal, through Grant No. PTDC/FIS-PLA/2940/2014 and PD/BD/105882/2014.

  8. The role of discharge variation in scaling of drainage area and food chain length in rivers

    Science.gov (United States)

    Sabo, John L.; Finlay, Jacques C.; Kennedy, Theodore A.; Post, David M.

    2010-01-01

    Food chain length (FCL) is a fundamental component of food web structure. Studies in a variety of ecosystems suggest that FCL is determined by energy supply, environmental stability, and/or ecosystem size, but the nature of the relationship between environmental stability and FCL, and the mechanism linking ecosystem size to FCL, remain unclear. Here we show that FCL increases with drainage area and decreases with hydrologic variability and intermittency across 36 North American rivers. Our analysis further suggests that hydrologic variability is the mechanism underlying the correlation between ecosystem size and FCL in rivers. Ecosystem size lengthens river food chains by integrating and attenuating discharge variation through stream networks, thereby enhancing environmental stability in larger river systems.

  9. Accurate switching intensities and length scales in quasi-phase-matched materials

    DEFF Research Database (Denmark)

    Bang, Ole; Graversen, Torben Winther; Corney, Joel Frederick

    2001-01-01

    We consider unseeded typeI second-harmonic generation in quasi-phase-matched quadratic nonlinear materials and derive an accurate analytical expression for the evolution of the average intensity. The intensity- dependent nonlinear phase mismatch that is due to the cubic nonlinearity induced...... by quasi phase matching is found. The equivalent formula for the intensity of maximum conversion, the crossing of which changes the one-period nonlinear phase shift of the fundamental abruptly by p , corrects earlier estimates [Opt.Lett. 23, 506 (1998)] by a factor of 5.3. We find the crystal lengths...... that are necessary to obtain an optimal flat phase versus intensity response on either side of this separatrix intensity....

  10. Chain length distributions in linear polyaddition proceeding in nano-scale small volumes without mass transfer

    Science.gov (United States)

    Szymanski, R.; Sosnowski, S.

    2017-01-01

    Computer simulations (Monte Carlo and numerical integration of differential equations) and theoretical analysis show that the statistical nature of polyaddition, both irreversible and reversible one, affects the way the macromolecules of different lengths are distributed among the small volume nano-reactors (droplets in this study) at any reaction time. The corresponding droplet distributions in respect to the number of reacting chains as well as the chain length distributions depend, for the given reaction time, on rate constants of polyaddition kp and depolymerization kd (reversible process), and the initial conditions: monomer concentration and the number of its molecules in a droplet. As a model reaction, a simple polyaddition process (M)1+(M)1 ⟶ ⟵ (M)2 , (M)i+(M)j ⟶ ⟵ (M)i+j was chosen, enabling to observe both kinetic and thermodynamic (apparent equilibrium constant) effects of a small number of reactant molecules in a droplet. The average rate constant of polymerization is lower than in a macroscopic system, depending on the average number of reactant molecules in a droplet. The apparent equilibrium constants of polymerization Ki j=[(M)i +j] ¯ /([(M)i] ¯ [(M)j] ¯ ) appear to depend on oligomer/polymer sizes as well as on the initial number of monomer molecules in a droplet. The corresponding equations, enabling prediction of the equilibrium conditions, were derived. All the analyzed effects are observed not only for ideally dispersed systems, i.e. with all droplets containing initially the same number of monomer (M)1 molecules, but also when initially the numbers of monomer molecules conform the Poisson distribution, expected for dispersions of reaction mixtures.

  11. Load dependency in force-length relations in isolated single cardiomyocytes.

    Science.gov (United States)

    Iribe, Gentaro; Kaneko, Toshiyuki; Yamaguchi, Yohei; Naruse, Keiji

    2014-08-01

    The previously reported pressure-volume (PV) relationship in frog hearts shows that end-systolic PV relation (ESPVR) is load dependent, whereas ESPVR in canine hearts is load independent. To study intrinsic cardiac mechanics in detail, it is desirable to study mechanics in a single isolated cardiomyocyte that is free from interstitial connective tissue. Previous single cell mechanics studies used a pair of carbon fibers (CF) attached to the upper surface of opposite cell ends to stretch cells. These studies showed that end-systolic force-length (FL) relation (ESFLR) is load independent. However, the range of applicable mechanical load using the conventional technique is limited because of weak cell-CF attachment. Therefore, the behavior of ESFLR in single cells under physiologically possible conditions of greater load is not yet well known. To cover wider loading range, we contrived a new method to hold cell-ends more firmly using two pairs of CF attached to both upper and bottom surfaces of cells. The new method allowed stretching cells to 2.2 μm or more in end-diastolic sarcomere length. ESFLR virtually behaves in a load independent manner only with end-diastolic sarcomere length less than 1.95 μm. It exhibited clear load dependency with higher preload, especially with low afterload conditions. Instantaneous cellular elastance curves showed that decreasing afterload enhanced relaxation and slowed time to peak elastance, as previously reported. A simulation study of a mathematical model with detailed description of thin filament activation suggested that velocity dependent thin filament inactivation is crucial for the observed load dependent behaviors and previously reported afterload dependent change in Ca(2+) transient shape. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Continuum and crystal strain gradient plasticity with energetic and dissipative length scales

    Science.gov (United States)

    Faghihi, Danial

    This work, standing as an attempt to understand and mathematically model the small scale materials thermal and mechanical responses by the aid of Materials Science fundamentals, Continuum Solid Mechanics, Misro-scale experimental observations, and Numerical methods. Since conventional continuum plasticity and heat transfer theories, based on the local thermodynamic equilibrium, do not account for the microstructural characteristics of materials, they cannot be used to adequately address the observed mechanical and thermal response of the micro-scale metallic structures. Some of these cases, which are considered in this dissertation, include the dependency of thin films strength on the width of the sample and diffusive-ballistic response of temperature in the course of heat transfer. A thermodynamic-based higher order gradient framework is developed in order to characterize the mechanical and thermal behavior of metals in small volume and on the fast transient time. The concept of the thermal activation energy, the dislocations interaction mechanisms, nonlocal energy exchange between energy carriers and phonon-electrons interactions are taken into consideration in proposing the thermodynamic potentials such as Helmholtz free energy and rate of dissipation. The same approach is also adopted to incorporate the effect of the material microstructural interface between two materials (e.g. grain boundary in crystals) into the formulation. The developed grain boundary flow rule accounts for the energy storage at the grain boundary due to the dislocation pile up as well as energy dissipation caused by the dislocation transfer through the grain boundary. Some of the abovementioned responses of small scale metallic compounds are addressed by means of the numerical implementation of the developed framework within the finite element context. In this regard, both displacement and plastic strain fields are independently discretized and the numerical implementation is performed in

  13. Large-scale tides in general relativity

    Energy Technology Data Exchange (ETDEWEB)

    Ip, Hiu Yan; Schmidt, Fabian, E-mail: iphys@mpa-garching.mpg.de, E-mail: fabians@mpa-garching.mpg.de [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching (Germany)

    2017-02-01

    Density perturbations in cosmology, i.e. spherically symmetric adiabatic perturbations of a Friedmann-Lemaȋtre-Robertson-Walker (FLRW) spacetime, are locally exactly equivalent to a different FLRW solution, as long as their wavelength is much larger than the sound horizon of all fluid components. This fact is known as the 'separate universe' paradigm. However, no such relation is known for anisotropic adiabatic perturbations, which correspond to an FLRW spacetime with large-scale tidal fields. Here, we provide a closed, fully relativistic set of evolutionary equations for the nonlinear evolution of such modes, based on the conformal Fermi (CFC) frame. We show explicitly that the tidal effects are encoded by the Weyl tensor, and are hence entirely different from an anisotropic Bianchi I spacetime, where the anisotropy is sourced by the Ricci tensor. In order to close the system, certain higher derivative terms have to be dropped. We show that this approximation is equivalent to the local tidal approximation of Hui and Bertschinger [1]. We also show that this very simple set of equations matches the exact evolution of the density field at second order, but fails at third and higher order. This provides a useful, easy-to-use framework for computing the fully relativistic growth of structure at second order.

  14. Intergenerational gains in relative knee height as compared to gains in relative leg length within Taiwanese families.

    Science.gov (United States)

    Floyd, B

    2008-01-01

    Evidence indicates that variation in relative leg length (RLL) is a sensitive indicator of early childhood circumstances, but research presents conflicting evidence of how lower leg growth contributes to variability. This study investigates the extent of intergenerational changes in subischial leg length and knee height relative to stature among father-son, mother-daughter, and midparent-offspring pairs. These changes and differences in the extent of mean change in the two indices within like-sex parent-offspring pairs were assessed using repeated measures ANOVA. Results indicate that within all categories, mean generational differences in both indices were substantial [Delta RLL z: 0.64-0.73; Delta relative knee height (RKH) z: 0.46-0.64] and statistically significant (P Auckland, though only the midparent-offspring generation by location contrast for RLL was statistically significant (P = 0.037). Father-son and mother-daughter average differences were virtually identical for RLL (0.73 z vs. 0.72 z). When differences within pairs in the extent of change in RLL and RKH were assessed directly, mother-daughter mean differences approached significance at an alpha level of 0.05 (Delta = 0.26 z; F = 3.42, df = 1, 42, P = 0.071). Father-son differences were smaller (Delta = 0.09 z) and statistically insignificant suggesting very similar amounts of change in the two indices. Copyright 2008 Wiley-Liss, Inc.

  15. EXPERIMENTAL INVESTIGATION OF RELATIVE PERMEABILITY UPSCALING FROM THE MICRO-SCALE TO THE MACRO-SCALE

    Energy Technology Data Exchange (ETDEWEB)

    JiangTao Cheng; Ping Yu; William Headley; Nicholas Giordao; Mirela Mustata; Daiquan Chen; Nathan Cooper; David D. Nolte; Laura J. Pyrak-Nolte

    2001-12-01

    The principal challenge of upscaling techniques for multi-phase fluid dynamics in porous media is to determine which properties on the micro-scale can be used to predict macroscopic flow and spatial distribution of phases at core- and field-scales. The most notable outcome of recent theories is the identification of interfacial areas per volume for multiple phases as a fundamental parameter that determines much of the multi-phase properties of the porous medium. A formal program of experimental research was begun to directly test upscaling theories in fluid flow through porous media by comparing measurements of relative permeability and capillary-saturation with measurements of interfacial area per volume. During this reporting period, we have shown experimentally and theoretically that the optical coherence imaging system is optimized for sandstone. The measurement of interfacial area per volume (IAV), capillary pressure and saturation in two dimensional micro-models structures that are statistically similar to real porous media has shown the existence of a unique relationship among these hydraulic parameters. The measurement of interfacial area per volume on a three-dimensional natural sample, i.e., sandstone, has the same length-scale as the values of IAV determined for the two-dimensional micro-models.

  16. Length of stay and associated costs of obesity related hospital admissions in Ireland.

    LENUS (Irish Health Repository)

    Vellinga, Akke

    2008-01-01

    BACKGROUND: Obesity is the cause of other chronic diseases, psychological problems, obesity shortens the lifespan and puts strain on health systems. The risk associated with childhood obesity in particular, which will accelerate the development of adult morbidity and mortality, has been identified as an emerging public health problem. METHODS: To estimate the length of stay and associated hospital costs for obesity related illnesses a cost of illness study was set up. All discharges from all acute hospitals in the Republic of Ireland from 1997 to 2004 with a principal or secondary diagnostic code for obesity for all children from 6 to 18 years of age and for adults were collected.A discharge frequency was calculated by dividing obesity related discharges by the total number of diagnoses (principal and secondary) for each year. The hospital costs related to obesity was calculated based on the total number of days care. RESULTS: The discharge frequency of obesity related conditions increased from 1.14 in 1997 to 1.49 in 2004 for adults and from 0.81 to 1.37 for children. The relative length of stay (number of days in care for obesity related conditions per 1000 days of hospital care given) increased from 1.47 in 1997 to 4.16 in 2004 for children and from 3.68 in 1997 to 6.74 in 2004 for adults.Based on the 2001 figures for cost per inpatient bed day, the annual hospital cost was calculated to be 4.4 Euromillion in 1997, increasing to 13.3 Euromillion in 2004. At a 20% variable hospital cost the cost ranges from 0.9 Euromillion in 1997 to 2.7 Euromillion in 2004; a 200% increase. CONCLUSION: The annual increase in the proportion of hospital discharges related to obesity is alarming. This increase is related to a significant increase in economic costs. This paper emphasises the need for action at an early stage of life. Health promotion and primary prevention of obesity should be high on the political agenda.

  17. Length of stay and associated costs of obesity related hospital admissions in Ireland

    Directory of Open Access Journals (Sweden)

    O'Donovan Diarmuid

    2008-04-01

    Full Text Available Abstract Background Obesity is the cause of other chronic diseases, psychological problems, obesity shortens the lifespan and puts strain on health systems. The risk associated with childhood obesity in particular, which will accelerate the development of adult morbidity and mortality, has been identified as an emerging public health problem. Methods To estimate the length of stay and associated hospital costs for obesity related illnesses a cost of illness study was set up. All discharges from all acute hospitals in the Republic of Ireland from 1997 to 2004 with a principal or secondary diagnostic code for obesity for all children from 6 to 18 years of age and for adults were collected. A discharge frequency was calculated by dividing obesity related discharges by the total number of diagnoses (principal and secondary for each year. The hospital costs related to obesity was calculated based on the total number of days care. Results The discharge frequency of obesity related conditions increased from 1.14 in 1997 to 1.49 in 2004 for adults and from 0.81 to 1.37 for children. The relative length of stay (number of days in care for obesity related conditions per 1000 days of hospital care given increased from 1.47 in 1997 to 4.16 in 2004 for children and from 3.68 in 1997 to 6.74 in 2004 for adults. Based on the 2001 figures for cost per inpatient bed day, the annual hospital cost was calculated to be 4.4 Euromillion in 1997, increasing to 13.3 Euromillion in 2004. At a 20% variable hospital cost the cost ranges from 0.9 Euromillion in 1997 to 2.7 Euromillion in 2004; a 200% increase. Conclusion The annual increase in the proportion of hospital discharges related to obesity is alarming. This increase is related to a significant increase in economic costs. This paper emphasises the need for action at an early stage of life. Health promotion and primary prevention of obesity should be high on the political agenda.

  18. ASSESSMENT OF ANAEROBIC CAPABILITIES OF FOOTBALL PLAYERS IN RELATION WITH LENGTH OF THEIR SPORTS ENGAGEMENT

    Directory of Open Access Journals (Sweden)

    Milan Cvetković

    2014-06-01

    Full Text Available Introduction: The general objective of this research is to determine how much influence the length of sports engagement has on anaerobic endurance of the football players, as well as on the maximum sprint ability of the players. In addition to the primary objective, the research seeks to determine the maximum power, minimum power, average power and fatigue index in players of cadet age group. Methods: The total sample of respondents in this study is made of 60 players of cadet age group (14-16 years of age, divided in relation to length of their sports engagement, into groups of up to 5 years (11 respondents, 6-7 years (21 respondents and from 8 to 10 years (28 respondents. The study used field RAST test. The RAST test was designed for sports where running is a basic form of movement. According to the protocol of the test respondents have ten minutes to warm up and five minutes to recover. That is followed by the performance of the test, which is composed of six 35-meter sprints at maximum speed. Between sprints respondent is allowed to pause for 10 seconds, intended primarily for turning and preparing for the next section. Based on the obtained time results from six 35-meter sprints, power is calculated for each run and then the following parameters are determined: maximum power (the highest value; minimum power (the lowest value ; average power (the sum of all six values/six and fatigue index which indicates the extent to which strength decreases for each respondent. This paper shall present a descriptive parameters, mean, standard deviation (SD, minimum and maximum of all values, the coefficient of variation (CV of confidence intervals, skewness as measure of asymmetry, kurtosis as measure of flatness and value of the Kolmogorov-Smirnov test. Multivariate procedures MANOVA and discriminant analysis shall be used. Out of univariate procedures ANOVA t-test and Roy’s test shall be applied. Results: Results obtained by multivariate analysis of

  19. Influence of DNA extraction methods on relative telomere length measurements and its impact on epidemiological studies.

    Science.gov (United States)

    Raschenberger, Julia; Lamina, Claudia; Haun, Margot; Kollerits, Barbara; Coassin, Stefan; Boes, Eva; Kedenko, Ludmilla; Köttgen, Anna; Kronenberg, Florian

    2016-05-03

    Measurement of telomere length is widely used in epidemiologic studies. Insufficient standardization of the measurements processes has, however, complicated the comparison of results between studies. We aimed to investigate whether DNA extraction methods have an influence on measured values of relative telomere length (RTL) and whether this has consequences for epidemiological studies. We performed four experiments with RTL measurement in quadruplicate by qPCR using DNA extracted with different methods: 1) a standardized validation experiment including three extraction methods (magnetic-particle-method EZ1, salting-out-method INV, phenol-chloroform-isoamyl-alcohol PCI) each in the same 20 samples demonstrated pronounced differences in RTL with lowest values with EZ1 followed by INV and PCI-isolated DNA; 2) a comparison of 307 samples from an epidemiological study showing EZ1-measurements 40% lower than INV-measurements; 3) a matching-approach of two similar non-diseased control groups including 143 pairs of subjects revealed significantly shorter RTL in EZ1 than INV-extracted DNA (0.844 ± 0.157 vs. 1.357 ± 0.242); 4) an association analysis of RTL with prevalent cardiovascular disease detected a stronger association with INV than with EZ1-extracted DNA. In summary, DNA extraction methods have a pronounced influence on the measured RTL-values. This might result in spurious or lost associations in epidemiological studies under certain circumstances.

  20. Role of Length Scales on Environmental Performance Metrics for Statistical Characterization of Well-Head Protection Regions

    Science.gov (United States)

    de Barros, F.; Guadagnini, A.; Fernandez-Garcia, D.; Riva, M.; Sanchez-Vila, X.

    2012-12-01

    We address the value of typically available hydrogeological information on environmental performance metrics (EPMs) as a function of several characteristic length scales that define groundwater flow and nonreactive solute transport in the presence of a pumping well. Improvement in the delineation of the well region of influence and reduction of the uncertainty associated with transport predictions is usually performed by means of hydrogeological sampling campaigns. We model aquifer heterogeneity through a spatially random hydraulic conductivity distribution and assess the ensuing uncertainty associated with predictions of key transport quantities conditioned to the probability that a distributed contaminant spill is captured by the well. We focus on the assessment of the impact of the acquisition of typical hydrogeological data on the reduction of uncertainty linked to the environmental scenario analyzed. We present a numerical investigation of the significance of the amount of available transmissivity measurements to yield predictions at a desired level of uncertainty of the following EPMs: (a) characteristic solute residence times in the system, and (b) the total mass exceeding a given threshold which is recovered by the well. We elucidate the role of the main (dimensionless) length scales that define and control the uncertainty associated with the target EPMs and infer a probabilistic model characterizing such uncertainty.

  1. Beam displacement as a function of temperature and turbulence length scale at two different laser radiation wavelengths.

    Science.gov (United States)

    Isterling, William M; Dally, Bassam B; Alwahabi, Zeyad T; Dubovinsky, Miro; Wright, Daniel

    2012-01-01

    Narrow laser beams directed from aircraft may at times pass through the exhaust plume of the engines and potentially degrade some of the laser beam characteristics. This paper reports on controlled studies of laser beam deviation arising from propagation through turbulent hot gases, in a well-characterized laboratory burner, with conditions of relevance to aircraft engine exhaust plumes. The impact of the temperature, laser wavelength, and turbulence length scale on the beam deviation has been investigated. It was found that the laser beam displacement increases with the turbulent integral length scale. The effect of temperature on the laser beam angular deviation, σ, using two different laser wavelengths, namely 4.67 μm and 632.8 nm, was recorded. It was found that the beam deviation for both wavelengths may be semiempirically modeled using a single function of the form, σ=a(b+(1/T)(2))(-1), with two parameters only, a and b, where σ is in microradians and T is the temperature in °C. © 2012 Optical Society of America

  2. Relation of Stump Length with Various Gait Parameters in Trans-tibial Amputee

    Directory of Open Access Journals (Sweden)

    Koyel Majumdar

    2008-07-01

    Full Text Available The purpose of this paper is evaluating the impact of stump length of unilateral below knee amputees (BKA on different gait parameters. Nine unilateral BKA were chosen and divided into three groups comprising patients with short, medium, and long stump length. Each of them underwent gait analysis test by Computer Dynography (CDG system to measure the gait parameters. It was found that the ground reaction force is higher in the patients with medium stump length whereas the velocity, step length both for the prosthetic and sound limb and cadence were high in longer stump length. Statistical analysis shows a significant difference (p<0.05 between the gait parameters of BKA with medium and longer stump length. The patients with longer stump length were more efficient than medium and short stump patients as they consumed comparatively lesser energy while walking with self-selected velocity and conventional (Solid ankle cushioned heel SACH foot.

  3. A multiple length scale description of the mechanism of elastomer stretching

    DEFF Research Database (Denmark)

    Neuefeind, J.; Skov, Anne Ladegaard; Daniels, J. E.

    2016-01-01

    for providing data on the structure of rubbers in the 2-50 angstrom range. First results relate to the elongation of a silicone rubber. We identify several non-entropic contributions to the free energy and describe the associated structural changes. By far the largest contribution comes from structural changes...... within the individual monomers, but among the contributions is also an elastic strain, acting between chains, which is 3-4 orders of magnitude smaller than the macroscopic strain, and of the opposite sign, i.e. extension of polymer chains in the direction perpendicular to the stretch. This may be due...

  4. On the validity of 2D critical taper theory in 3D wedges: defining a lateral deformation length scale

    Science.gov (United States)

    Leever, Karen; Oncken, Onno; Thorden Haug, Øystein

    2015-04-01

    For 2D critical taper theory to be applicable to 3D natural cases, cylindric deformation is a requirement. The assumption of cylindricity is violated in case of localized perturbations (subducting seamount, localized sedimentation) or due to a lateral change in decollement strength or depth. In natural accretionary wedges and fold-and-thrust belts, along strike changes may occur in a variety of ways: geometrical (due to a protruding indenter or a change in decollement depth), through a lateral change in basal friction (leading to laterally different tapers), or through a change in surface slope (by strongly localized fan sedimentation on accretionary wedges). Recent numerical modelling results (Ruh et al., 2013) have shown that lateral coupling preferentially occurs for relatively small perturbations, i.e. the horizontal shear stress caused by the perturbation is supported by the system. Lateral linking of the wedge in front of a protruding indenter to the wedge in front of the trailing edge of the back stop leads to curved thrust fronts and importantly it has been noted that even outside the curved zone, where the wedge front is again parallel to the direction of tectonic transport, the lateral effect is still evident: both tapers are different from the analytical prediction. We present results from a 3D analogue modelling parameter study to investigate this behavior more quantitatively, with the objective of empirically finding a lateral length scale of deformation in brittle contractional wedges. For a given wedge strength (angle of internal friction), we infer this to be a function of the size (width) of the perturbation and its magnitude (difference in basal friction). To this end we run different series of models in which we systematically vary the width and/or magnitude of a local perturbation. In the first series, the width of a zone of high basal friction is varied, in the second series we vary the width of an indenter and in the third series

  5. Nearly constant ratio between the proton inertial scale and the spectrum break length scale in the plasma beta range from 0.2 to 1.4 in the solar wind turbulence

    Science.gov (United States)

    Wang, X.; Tu, C. Y.; He, J.; Wang, L.

    2017-12-01

    The spectrum break at the ion scale of the solar wind magnetic fluctuations are considered to give important clue on the turbulence dissipation mechanism. Among several possible mechanisms, the most notable ones are the two mechanisms that related respectively with proton thermal gyro-radius and proton inertial length. However, no definite conclusion has been given for which one is more reasonable because the two parameters have similar values in the normal plasma beta range. Here we do a statistical study for the first time to see if the two mechanism predictions have different dependence on the solar wind velocity and on the plasma beta in the normal plasma beta range in the solar wind at 1 AU. From magnetic measurements by Wind, Ulysses and Messenger, we select 60 data sets with duration longer than 8 hours. We found that the ratio between the proton inertial scale and the spectrum break scale do not change considerably with both varying the solar wind speed from 300km/s to 800km/s and varying the plasma beta from 0.2 to 1.4. The average value of the ratio times 2pi is 0.46 ± 0.08. However, the ratio between the proton gyro-radius and the break scale changes clearly. This new result shows that the proton inertial scale could be a single factor that determines the break length scale and hence gives a strong evidence to support the dissipation mechanism related to it in the normal plasma beta range. The value of the constant ratio may relate with the dissipation mechanism, but it needs further theoretical study to give detailed explanation.

  6. Electrochemical and Friction Characteristics of Metallic Glass Composites at the Microstructural Length-scales.

    Science.gov (United States)

    Ayyagari, Aditya; Hasannaeimi, Vahid; Arora, Harpreet; Mukherjee, Sundeep

    2018-01-17

    Metallic glass composites represent a unique alloy design strategy comprising of in situ crystalline dendrites in an amorphous matrix to achieve damage tolerance unseen in conventional structural materials. They are promising for a range of advanced applications including spacecraft gears, high-performance sporting goods and bio-implants, all of which demand high surface degradation resistance. Here, we evaluated the phase-specific electrochemical and friction characteristics of a Zr-based metallic glass composite, Zr 56.2 Ti 13.8 Nb 5.0 Cu 6.9 Ni 5.6 Be 12.5 , which comprised roughly of 40% by volume crystalline dendrites in an amorphous matrix. The amorphous matrix showed higher hardness and friction coefficient compared to the crystalline dendrites. But sliding reciprocating tests for the composite revealed inter-phase delamination rather than preferred wearing of one phase. Pitting during potentiodynamic polarization in NaCl solution was prevalent at the inter-phase boundary, confirming that galvanic coupling was the predominant corrosion mechanism. Scanning vibration electrode technique demonstrated that the amorphous matrix corroded much faster than the crystalline dendrites due to its unfavorable chemistry. Relative work function values measured using scanning kelvin probe showed the amorphous matrix to be more electropositive, which explain its preferred corrosion over the crystalline dendrites as well as its characteristic friction behavior. This study paves the way for careful partitioning of elements between the two phases in a metallic glass composite to tune its surface degradation behavior for a range of advanced applications.

  7. Scale-Independent Relational Query Processing

    Science.gov (United States)

    2013-10-04

    customer relationship management ( CRM ) are also being forced to build software capable of quickly growing to a previously unimaginable scale. Salesforce.com...Huang and Armando Fox. “ Cheap recovery: a key to self-managing state”. In: Trans. Storage 1.1 (Feb. 2005), pp. 38–70. issn: 1553-3077. doi: 10.1145

  8. Magneto-Induced ac Electrical Permittivity of Metal-Dielectric Composites with a Two Characteristic Length Scales Periodic Microstructure

    International Nuclear Information System (INIS)

    Strelniker, Y.M.; Bergman, D.J.

    1998-01-01

    A new effect was recently predicted in conducting composites that have a periodic microstructure: an induced strongly anisotropic dc magneto-resistance. This phenomenon is already verified on high mobility n-GaAs films. Here we discuss the possibility of observing analogous behavior in the ac electric permittivity of a metal-dielectric composite with a periodic microstructure in the presence of a strong magnetic field. We developed new analytical and numerical methods to treat the low-frequency magneto-optical properties in composite media with both disordered and periodic conducting micro-structures. Those methods allow us to study composites with inclusions of arbitrary shape (and arbitrary volume fraction) at arbitrarily strong magnetic field. This is exploited in order to calculate an effective dielectric tensor for this system as a function of applied magnetic field and ac frequency. We show that in a non-dilute metal-dielectric composite medium the magneto-plasma resonance and the cyclotron resonance depend upon both the applied magnetic field as well as on the geometric shape of the inclusion. Near such a resonance, it is possible to achieve large values for the ratio of the off-diagonal-to-diagonal electric permittivity tensor components, ε xy /ε xx , (since ε xx →0, while ε xy ≠0), which is analogous to similar ratio of the resistivity tensor components, ρ xy /ρ xx , in the case of dc magneto-transport problem. Motivated by this observation and by results of previous studies of dc magneto-transport in composite conductors, we then performed a numerical study of the ac magneto-electric properties of a particular metal-dielectric composite film with a periodic columnar microstructure which has a two characteristic length scales. The unit cell of such composite is prepared as follows: We placed the conducting square (in cross section) rods (first characteristic length scale) along the perimeter of the unit cell in order to create a dielectric host

  9. On the relation between reading difficulty and mind-wandering: a section-length account.

    Science.gov (United States)

    Forrin, Noah D; Risko, Evan F; Smilek, Daniel

    2017-11-01

    In many situations, increasing task difficulty decreases thoughts that are unrelated to the task (i.e., mind-wandering). In the context of reading, however, recent research demonstrated that increasing passage reading difficulty actually increases mind-wandering rates (e.g., Feng et al. in Psychon Bull Rev 20:586-592, 2013). The primary goal of this research was to elucidate the mechanism that drives this positive relation. Across Experiments 1-3, we found evidence that the effect of Flesch-Kincaid reading difficulty on mind-wandering is partially driven by hard passages having longer sections of text (i.e., more words per screen) than easy passages when passages are presented one sentence at a time. In Experiment 4, we controlled for reading difficulty, and found that section length was positively associated with mind-wandering rates. We conclude by proposing that individuals may tend to disengage their attention from passages with relatively long sections of text because they appear to be more demanding than passages with shorter sections (even though objective task demands are equivalent).

  10. Scaling Relation for Occulter Manufacturing Errors

    Science.gov (United States)

    Sirbu, Dan; Shaklan, Stuart B.; Kasdin, N. Jeremy; Vanderbei, Robert J.

    2015-01-01

    An external occulter is a spacecraft own along the line-of-sight of a space telescope to suppress starlight and enable high-contrast direct imaging of exoplanets. The shape of an external occulter must be specially designed to optimally suppress starlight and deviations from the ideal shape due to manufacturing errors can result loss of suppression in the shadow. Due to the long separation distances and large dimensions involved for a space occulter, laboratory testing is conducted with scaled versions of occulters etched on silicon wafers. Using numerical simulations for a flight Fresnel occulter design, we show how the suppression performance of an occulter mask scales with the available propagation distance for expected random manufacturing defects along the edge of the occulter petal. We derive an analytical model for predicting performance due to such manufacturing defects across the petal edges of an occulter mask and compare this with the numerical simulations. We discuss the scaling of an extended occulter test-bed.

  11. Predicting permeability of regular tissue engineering scaffolds: scaling analysis of pore architecture, scaffold length, and fluid flow rate effects.

    Science.gov (United States)

    Rahbari, A; Montazerian, H; Davoodi, E; Homayoonfar, S

    2017-02-01

    The main aim of this research is to numerically obtain the permeability coefficient in the cylindrical scaffolds. For this purpose, a mathematical analysis was performed to derive an equation for desired porosity in terms of morphological parameters. Then, the considered cylindrical geometries were modeled and the permeability coefficient was calculated according to the velocity and pressure drop values based on the Darcy's law. In order to validate the accuracy of the present numerical solution, the obtained permeability coefficient was compared with the published experimental data. It was observed that this model can predict permeability with the utmost accuracy. Then, the effect of geometrical parameters including porosity, scaffold pore structure, unit cell size, and length of the scaffolds as well as entrance mass flow rate on the permeability of porous structures was studied. Furthermore, a parametric study with scaling laws analysis of sample length and mass flow rate effects on the permeability showed good fit to the obtained data. It can be concluded that the sensitivity of permeability is more noticeable at higher porosities. The present approach can be used to characterize and optimize the scaffold microstructure due to the necessity of cell growth and transferring considerations.

  12. Large-scale amplification, cloning and sequencing of near full-length HIV-1 subtype C genomes.

    Science.gov (United States)

    Rousseau, Christine M; Birditt, Brian A; McKay, Angela R; Stoddard, Julia N; Lee, Tsan Chun; McLaughlin, Sherry; Moore, Sarah W; Shindo, Nice; Learn, Gerald H; Korber, Bette T; Brander, Christian; Goulder, Philip J R; Kiepiela, Photini; Walker, Bruce D; Mullins, James I

    2006-09-01

    Full-length HIV-1 genome sequencing provides important data needed to address several vaccine design, molecular epidemiologic and pathogenesis questions. A protocol is presented for obtaining near full-length genomes (NFLGs) from subjects infected with HIV-1 subtype C. This protocol was used to amplify NFLGs from 244 of 366 (67%) samples collected at two clinics in Durban, South Africa (SK and PS). Viral load was directly associated with frequency of successful NFLG amplification for both cohorts (PS; p = 0.005 and SK; p clones were obtained from all 244 NFLG-positive PCR products, and both strands of each genome were sequenced, using a primary set of 46 primers. These methods thus allow the large-scale collection of HIV-1 NFLGs from populations infected primarily with subtype C. The methods are readily adaptable to other HIV-1 subtypes, and provide materials for viral functional analyses and population-based molecular epidemiology studies that include analysis of viral genome chimerization.

  13. Influence of Growth Rate on Microstructural Length Scales in Directionally Solidified NiAl-Mo Hypo-Eutectic Alloy

    Science.gov (United States)

    Zhang, Jianfei; Ma, Xuewei; Ren, Huiping; Chen, Lin; Jin, Zili; Li, Zhenliang; Shen, Jun

    2016-01-01

    In this article, the Ni-46.1Al-7.8Mo (at.%) alloy was directionally solidified at different growth rates ranging from 15 μm/s to 1000 μm/s under a constant temperature gradient (334 K/cm). The dependence of microstructural length scales on the growth rate was investigated. The results show that, with the growth rate increasing, the primary dendritic arm spacings (PDAS) and secondary dendritic arm spacings (SDAS) decreased. There exists a large distribution range in PDAS under directional solidification conditions at a constant temperature gradient. The average PDAS and SDAS as a function of growth rate can be given as λ1 = 848.8967 V-0.4509 and λ2 = 64.2196 V-0.4140, respectively. In addition, a comparison of our results with the current theoretical models and previous experimental results has also been made.

  14. Length-scales of Slab-induced Asthenospheric Deformation from Geodynamic Modeling, Mantle Deformation Fabric, and Synthetic Shear Wave Splitting

    Science.gov (United States)

    Jadamec, M. A.; MacDougall, J.; Fischer, K. M.

    2017-12-01

    The viscosity structure of the Earth's interior is critically important, because it places a first order constraint on plate motion and mantle flow rates. Geodynamic models using a composite viscosity based on experimentally derived flow laws for olivine aggregates show that lateral viscosity variations emerge in the upper mantle due to the subduction dynamics. However, the length-scale of this transition is still not well understood. Two-dimensional numerical models of subduction are presented that investigate the effect of initial slab dip, maximum yield stress (slab strength), and viscosity formulation (Newtonian versus composite) on the emergent lateral viscosity variations in the upper-mantle and magnitude of slab-driven mantle flow velocity. Significant viscosity reductions occur in regions of large flow velocity gradients due to the weakening effect of the dislocation creep deformation mechanism. The dynamic reductions in asthenospheric viscosity (less than 1018 Pa s) occur within approximately 500 km from driving force of the slab, with peak flow velocities occurring in models with a lower yield stress (weaker slab) and higher stress exponent. This leads to a sharper definition of the rheological base of the lithosphere and implies lateral variability in tractions along the base of the lithosphere. As the dislocation creep mechanism also leads to mantle deformation fabric, we then examine the spatial variation in the LPO development in the asthenosphere and calculate synthetic shear wave splitting. The models show that olivine LPO fabric in the asthenosphere generally increases in alignment strength with increased proximity to the slab, but can be transient and spatially variable on small length scales. The vertical flow fields surrounding the slab tip can produce shear-wave splitting variations with back-azimuth that deviate from the predictions of uniform trench-normal anisotropy, a result that bears on the interpretation of complexity in shear

  15. Smoking and perceived stress in relation to short salivary telomere length among caregivers of children with disabilities.

    Science.gov (United States)

    Chen, Xiaoli; Velez, Juan Carlos; Barbosa, Clarita; Pepper, Micah; Andrade, Asterio; Stoner, Lee; De Vivo, Immaculata; Gelaye, Bizu; Williams, Michelle A

    2015-01-01

    Telomere length (TL), the length of repeated DNA sequence that forms protective caps at the end of chromosomes, has emerged as a novel biomarker of cell aging and oxidative stress. There is increasing research exploring the associations of smoking and perceived stress with TL, and the results are inconsistent. This study aimed to examine whether smoking and perceived stress were associated with shortened salivary TL among primary caregivers of children with disabilities. Using a quantitative polymerase chain reaction method, salivary TL was assessed among 89 caregivers aged 19-69 years (87% were women) who took care of disabled children in the Patagonia Region, Chile. Interviewer-administered questionnaires were used to collect information on sociodemographic and lifestyle factors. The 14-item Perceived Stress Scale was used to assess perceived stress. Mean relative TL was 0.92 (standard error = 0.03). Smokers had age-adjusted mean TL that was 0.07 units lower (β = -0.07, standard error = 0.03; p = 0.012) than non-smokers. Smokers were 2.17 times more likely to have shorter TL ( perceived stress. Caregivers with higher perceived stress were 2.13 times more likely to have shorter TL (odds ratio = 3.13; 95% confidence interval = 1.03-9.55) than caregivers with lower perceived stress after adjustment for age and smoking. This study provides the first evidence of strong associations between smoking and perceived stress and shortened salivary TL among caregivers of children with disabilities. Larger studies with detailed information on smoking status are warranted to confirm our findings.

  16. Select injury-related variables are affected by stride length and foot strike style during running.

    Science.gov (United States)

    Boyer, Elizabeth R; Derrick, Timothy R

    2015-09-01

    Some frontal plane and transverse plane variables have been associated with running injury, but it is not known if they differ with foot strike style or as stride length is shortened. To identify if step width, iliotibial band strain and strain rate, positive and negative free moment, pelvic drop, hip adduction, knee internal rotation, and rearfoot eversion differ between habitual rearfoot and habitual mid-/forefoot strikers when running with both a rearfoot strike (RFS) and a mid-/forefoot strike (FFS) at 3 stride lengths. Controlled laboratory study. A total of 42 healthy runners (21 habitual rearfoot, 21 habitual mid-/forefoot) ran overground at 3.35 m/s with both a RFS and a FFS at their preferred stride lengths and 5% and 10% shorter. Variables did not differ between habitual groups. Step width was 1.5 cm narrower for FFS, widening to 0.8 cm as stride length shortened. Iliotibial band strain and strain rate did not differ between foot strikes but decreased as stride length shortened (0.3% and 1.8%/s, respectively). Pelvic drop was reduced 0.7° for FFS compared with RFS, and both pelvic drop and hip adduction decreased as stride length shortened (0.8° and 1.5°, respectively). Peak knee internal rotation was not affected by foot strike or stride length. Peak rearfoot eversion was not different between foot strikes but decreased 0.6° as stride length shortened. Peak positive free moment (normalized to body weight [BW] and height [h]) was not affected by foot strike or stride length. Peak negative free moment was -0.0038 BW·m/h greater for FFS and decreased -0.0004 BW·m/h as stride length shortened. The small decreases in most variables as stride length shortened were likely associated with the concomitant wider step width. RFS had slightly greater pelvic drop, while FFS had slightly narrower step width and greater negative free moment. Shortening one's stride length may decrease or at least not increase propensity for running injuries based on the variables

  17. Myopia, axial length, and age-related cataract: the Singapore Malay eye study.

    Science.gov (United States)

    Pan, Chen-Wei; Boey, Pui Yi; Cheng, Ching-Yu; Saw, Seang-Mei; Tay, Wan Ting; Wang, Jie Jin; Tan, Ava Grace; Mitchell, Paul; Wong, Tien Yin

    2013-07-02

    To describe the associations of myopia and axial length (AL) with age-related cataract in an Asian population in Singapore. A population-based cross-sectional study that examined 3280 (78.7% response) adults of Malay ethnicity aged 40 to 80 years. Refractive error was determined by subjective refraction and AL was measured using the Zeiss IOL-Master. Digital slit lamp and retroillumination lens photographs were taken and graded for age-related nuclear, cortical, and posterior subcapsular (PSC) cataract following the Wisconsin system. After excluding eyes with prior refractive or cataract surgery, 5474 eyes with gradable lens photographs were analyzed. In multivariate analyses adjusting for age, sex, body mass index, systolic blood pressure, glycosylated hemoglobin, smoking status, and education, myopia (spherical equivalent less than -0.5 diopter [D]) was associated with an increased prevalence of nuclear (OR: 4.99, 95% CI: 3.72–6.69) and PSC cataract (OR: 1.34, 95% CI: 1.30-1.39) but not with cortical cataract (OR: 0.85, 95% CI: 0.68-1.08) compared with emmetropia. Per-millimeter increase in AL was not associated with any of the three cataract subtypes. When myopia was defined as spherical equivalent of less than -5.0 D to -6.0 D, the OR of myopia for PSC cataract increased dramatically. Our study shows that myopia, but not AL, was associated with nuclear cataract, supporting the concept of index myopia with aging. Myopia, especially high myopia, may predispose to PSC cataract formation. Clinically, ophthalmologists should be aware that risk of PSC cataract appears to vary by refractive status.

  18. Hydrocephalus during rehabilitation following severe TBI. Relation to recovery, outcome, and length of stay

    DEFF Research Database (Denmark)

    Linnemann, Mia; Tibæk, Maiken; Kammersgaard, Lars Peter

    2014-01-01

    rehabilitation. METHODS: We studied 417 patients with severe TBI admitted consecutively to a single hospital - based neurorehabilitation department serving Eastern Denmark between 2000 and 2010. Demographics (age and gender) and clinical characteristics (length of acute treatment, post traumatic amnesia (PTA...

  19. Study on the Workspace of a 6-DOF Parallel Topology Robot Related to Binary Link Lengths

    Directory of Open Access Journals (Sweden)

    Calin-Octavian Miclosina

    2016-12-01

    Full Text Available The paper presents a study on the workspace of a parallel topology robot with the structure FP3+6•SPS+MP3. The variable parameters are the binary link lengths, from both upper and lower levels, and the driving kinematical joint strokes. The workspace boundary is determined by SolidWorks software simulations. For different binary link lengths, workspace volume is determined and sections through the workspace are presented.

  20. On mechanics and material length scales of failure in heterogeneous interfaces using a finite strain high performance solver

    Science.gov (United States)

    Mosby, Matthew; Matouš, Karel

    2015-12-01

    Three-dimensional simulations capable of resolving the large range of spatial scales, from the failure-zone thickness up to the size of the representative unit cell, in damage mechanics problems of particle reinforced adhesives are presented. We show that resolving this wide range of scales in complex three-dimensional heterogeneous morphologies is essential in order to apprehend fracture characteristics, such as strength, fracture toughness and shape of the softening profile. Moreover, we show that computations that resolve essential physical length scales capture the particle size-effect in fracture toughness, for example. In the vein of image-based computational materials science, we construct statistically optimal unit cells containing hundreds to thousands of particles. We show that these statistically representative unit cells are capable of capturing the first- and second-order probability functions of a given data-source with better accuracy than traditional inclusion packing techniques. In order to accomplish these large computations, we use a parallel multiscale cohesive formulation and extend it to finite strains including damage mechanics. The high-performance parallel computational framework is executed on up to 1024 processing cores. A mesh convergence and a representative unit cell study are performed. Quantifying the complex damage patterns in simulations consisting of tens of millions of computational cells and millions of highly nonlinear equations requires data-mining the parallel simulations, and we propose two damage metrics to quantify the damage patterns. A detailed study of volume fraction and filler size on the macroscopic traction-separation response of heterogeneous adhesives is presented.

  1. Age-related declines and disease-associated variation in immune cell telomere length in a wild mammal.

    Directory of Open Access Journals (Sweden)

    Christopher Beirne

    Full Text Available Immunosenescence, the deterioration of immune system capability with age, may play a key role in mediating age-related declines in whole-organism performance, but the mechanisms that underpin immunosenescence are poorly understood. Biomedical research on humans and laboratory models has documented age and disease related declines in the telomere lengths of leukocytes ('immune cells', stimulating interest their having a potentially general role in the emergence of immunosenescent phenotypes. However, it is unknown whether such observations generalise to the immune cell populations of wild vertebrates living under ecologically realistic conditions. Here we examine longitudinal changes in the mean telomere lengths of immune cells in wild European badgers (Meles meles. Our findings provide the first evidence of within-individual age-related declines in immune cell telomere lengths in a wild vertebrate. That the rate of age-related decline in telomere length appears to be steeper within individuals than at the overall population level raises the possibility that individuals with short immune cell telomeres and/or higher rates of immune cell telomere attrition may be selectively lost from this population. We also report evidence suggestive of associations between immune cell telomere length and bovine tuberculosis infection status, with individuals detected at the most advanced stage of infection tending to have shorter immune cell telomeres than disease positive individuals. While male European badgers are larger and show higher rates of annual mortality than females, we found no evidence of a sex difference in either mean telomere length or the average rate of within-individual telomere attrition with age. Our findings lend support to the view that age-related declines in the telomere lengths of immune cells may provide one potentially general mechanism underpinning age-related declines in immunocompetence in natural populations.

  2. Pessimistic orientation in relation to telomere length in older men: the VA Normative Aging Study

    Science.gov (United States)

    Ikeda, Ai; Schwartz, Joel; Peters, Junenette L.; Baccarelli, Andrea A.; Hoxha, Mirjam; Dioni, Laura; Spiro, Avron; Sparrow, David; Vokonas, Pantel; Kubzansky, Laura D.

    2014-01-01

    Background Recent research suggests pessimistic orientation is associated with shorter leukocyte telomere length (LTL). However, this is the first study to look not only at effects of pessimistic orientation on average LTL at multiple time points, but also at effects on the rate of change in LTL over time. Methods Participants were older men from the VA Normative Aging Study (n=490). The Life Orientation Test (LOT) was used to measure optimistic and pessimistic orientations at study baseline, and relative LTL by telomere to single copy gene ratio (T:S ratio) was obtained repeatedly over the course of the study (1999-2008). A total of 1,010 observations were included in the analysis. Linear mixed effect models with a random subject intercept were used to estimate associations. Results Higher pessimistic orientation scores were associated with shorter average LTL (percent difference by 1-SD increase in pessimistic orientation (95% CI): -3.08 (-5.62, -0.46)), and the finding was maintained after adjusting for the higher likelihood that healthier individuals return for follow-up visits (-3.44 (-5.95,-0.86)). However, pessimistic orientation scores were not associated with rate of change in LTL over time. No associations were found between overall optimism and optimistic orientation subscale scores and LTL. Conclusion Higher pessimistic orientation scores were associated with shorter LTL in older men. While there was no evidence that pessimistic orientation was associated with rate of change in LTL over time, higher levels of pessimistic orientation were associated with shorter LTL at baseline and this association persisted over time. PMID:24636503

  3. Special relativity at the quantum scale.

    Directory of Open Access Journals (Sweden)

    Pui K Lam

    Full Text Available It has been suggested that the space-time structure as described by the theory of special relativity is a macroscopic manifestation of a more fundamental quantum structure (pre-geometry. Efforts to quantify this idea have come mainly from the area of abstract quantum logic theory. Here we present a preliminary attempt to develop a quantum formulation of special relativity based on a model that retains some geometric attributes. Our model is Feynman's "checker-board" trajectory for a 1-D relativistic free particle. We use this model to guide us in identifying (1 the quantum version of the postulates of special relativity and (2 the appropriate quantum "coordinates". This model possesses a useful feature that it admits an interpretation both in terms of paths in space-time and in terms of quantum states. Based on the quantum version of the postulates, we derive a transformation rule for velocity. This rule reduces to the Einstein's velocity-addition formula in the macroscopic limit and reveals an interesting aspect of time. The 3-D case, time-dilation effect, and invariant interval are also discussed in term of this new formulation. This is a preliminary investigation; some results are derived, while others are interesting observations at this point.

  4. Special relativity at the quantum scale.

    Science.gov (United States)

    Lam, Pui K

    2014-01-01

    It has been suggested that the space-time structure as described by the theory of special relativity is a macroscopic manifestation of a more fundamental quantum structure (pre-geometry). Efforts to quantify this idea have come mainly from the area of abstract quantum logic theory. Here we present a preliminary attempt to develop a quantum formulation of special relativity based on a model that retains some geometric attributes. Our model is Feynman's "checker-board" trajectory for a 1-D relativistic free particle. We use this model to guide us in identifying (1) the quantum version of the postulates of special relativity and (2) the appropriate quantum "coordinates". This model possesses a useful feature that it admits an interpretation both in terms of paths in space-time and in terms of quantum states. Based on the quantum version of the postulates, we derive a transformation rule for velocity. This rule reduces to the Einstein's velocity-addition formula in the macroscopic limit and reveals an interesting aspect of time. The 3-D case, time-dilation effect, and invariant interval are also discussed in term of this new formulation. This is a preliminary investigation; some results are derived, while others are interesting observations at this point.

  5. Special Relativity at the Quantum Scale

    Science.gov (United States)

    Lam, Pui K.

    2014-01-01

    It has been suggested that the space-time structure as described by the theory of special relativity is a macroscopic manifestation of a more fundamental quantum structure (pre-geometry). Efforts to quantify this idea have come mainly from the area of abstract quantum logic theory. Here we present a preliminary attempt to develop a quantum formulation of special relativity based on a model that retains some geometric attributes. Our model is Feynman's “checker-board” trajectory for a 1-D relativistic free particle. We use this model to guide us in identifying (1) the quantum version of the postulates of special relativity and (2) the appropriate quantum “coordinates”. This model possesses a useful feature that it admits an interpretation both in terms of paths in space-time and in terms of quantum states. Based on the quantum version of the postulates, we derive a transformation rule for velocity. This rule reduces to the Einstein's velocity-addition formula in the macroscopic limit and reveals an interesting aspect of time. The 3-D case, time-dilation effect, and invariant interval are also discussed in term of this new formulation. This is a preliminary investigation; some results are derived, while others are interesting observations at this point. PMID:25531675

  6. The Long-Term Effect on Children of Increasing the Length of Parents' Birth-Related Leave

    DEFF Research Database (Denmark)

    Wurtz, Astrid

    The length of parents' birth-related leave varies across countries and has been subject of some debate. In this paper, I will focus on some potential benefits of leave. I investigate the long-term effects on children of increasing the length of parents' birth-related leave using a natural...... and educational outcomes at ages 15 and 21. A population sample of Danish children born in the months around implementation of the reform and a dataset with Danish PISA-2000 scores are used for the analysis. Results indicate that increasing parents' access to birth-related leave has no measurable effect...... on children's long-term cognitive outcomes....

  7. Length variation in the internal transcribed spacers of ribosomal DNA in Picea abies and related species.

    Science.gov (United States)

    Karvonen, P; Szmidt, A E; Savolainen, O

    1994-12-01

    The structure and variation of nuclear ribosomal DNA (rDNA) units of Picea abies, (L.) Karst. was studied by restriction mapping and Southern hybridization. Conspicuous length variation was found in the internal transcribed spacer (ITS) region of P. abies, although the length of this region is highly conserved both within and among most of the plant species. Two types of ITS variants (A and B), displaying a size difference of 0.5 kb in the ITS2 region, were present within individuals of P. abies from Sweden, Central Europe and Siberia. A preliminary survey of 14 additional Eurasian and North American species of Picea suggested that length variation in the ITS region is widespread in this genus. Alltogether three length variants (A, B and C) were identified. Within individuals of eight Picea species, two length variants were present within the genome (combinations of A and B variants in P. glehnii, P. maximowiczii, P. omorika, P. polita and P. sitchensis and variants B and C in P. jezoensis, P. likiangensis and P. spinulosa). Within individuals from five species, however only one rDNA variant was present in their genome (variant A in P. aurantiaca, P. engelmannii, P. glauca, P. koraiensis and P. koyamai; variant B in P. bicolor). The ITS length variation will be useful as a molecular marker in evolutionary studies of the Picea species complex, whose phylogeny is controversial. The presence of intraindividual variation in, and shared polymorphism of the, ITS length variants raises questions about the occurrence of interspecific hybridization during the evolutionary history of Picea.

  8. Cross-Sectional Study of the Relation of Health Literacy to Primary Language and Emergency Department Length of Stay.

    Science.gov (United States)

    Sarangarm, Dusadee; Ernst, Amy; Horner, Rachel; Crum, Ashley; Weiss, Steven J; Zemkova, Yana; King, Kisa

    2017-12-01

    The primary aim of this study was to determine whether emergency department (ED) length of stay (LOS) or primary language was related to the degree of health literacy of patients. Adult English-speaking and Spanish-speaking patients were recruited for the study. Participants completed the Newest Vital Sign (NVS) tool (English and Spanish versions), a 6-question validated scale. Patients with NVS scores of 0 to 3 were considered to be at risk for limited health literacy, whereas those with adequate health literacy were defined as scoring a 4 to 6. After completion of their ED visit, a retrospective chart review was performed to identify the patient's ED LOS (time from registration to time of disposition) and ED disposition. In addition, 2 single-item questions were compared with the NVS for validity. Participants included 250 English-speaking and 257 Spanish-speaking subjects. Per the NVS, 71% (359 of 507) of all patients had limited health literacy. By language group, significantly more Spanish-speaking than English-speaking patients had limited health literacy (93% vs 48%, diff 45%, 95% confidence interval 37-51). There was no significant difference in LOS between the limited health literacy group and adequate health literacy group (medians 440 vs 461 min). The 2 single-item questions had fair validity in comparison to the NVS scale (κ 0.2-0.3). There was a significant difference in health literacy based on language, with 93% of all Spanish-speaking patients in our sample having limited health literacy. We found no significant difference in ED LOS between patients with limited health and adequate health literacy in an academic urban ED setting.

  9. Return to work after lumbar disc surgery is related to the length of preoperative sick leave

    DEFF Research Database (Denmark)

    Andersen, Mikkel Ø; Ernst, Carsten; Rasmussen, Jesper

    2017-01-01

    INTRODUCTION: Lumbar disc herniation (LDH) is associated with high morbidity and significant socio-economic impact as the majority of the patients are of working age. The purpose of this study was to determine the impact of length of sick leave on the return-to-work rate after lumbar disc......% returned to work if surgically treated within three months. In contrast, only 50% of those whose sick leave exceeded three months returned to work. CONCLUSION: The present analysis suggests that the return-to-work rate after lumbar disc herniation surgery is affected by the length of sick leave. FUNDING...... herniation surgery. METHODS: This was a single-centre study of LDH patients who underwent surgery from 18 May 2009 through 28 November 2014. Data were collected prospectively from the DaneSpine database. Questions in DaneSpine include preoperative length of sick leave and working status one year post...

  10. Exploring the Personal and Environmental Factors Related to Length of Stay in Assisted Living.

    Science.gov (United States)

    Fields, Noelle L

    2016-04-01

    This study explored to what extent personal and environmental factors, as defined by the ecological model of aging, help us to understand length of stay in assisted living (AL). A convenience sample (N = 218) of administrative records of AL residents admitted between the years 2006 and 2011 was collected and included AL residents' demographic and healthcare information as well as dates of admission and discharge. Cox regression was used to determine which personal and environmental factors influenced length of stay in three AL programs. Number of medical diagnoses, level of care score, and facility were found to be significant predictors of length of stay. The analyses identified a median survival time of 32 months as well as critical periods for discharge from AL. Implications for future research and social work practice are presented.

  11. The Long-Term Effect on Children of Increasing the Length of Parents' Birth-Related Leave

    DEFF Research Database (Denmark)

    Wurtz, Astrid

    The length of parents. birth-related leave varies across countries and has been subject of some debate. I investigate the long-term e¤ects on children of increasing the length of parents.birth-related leave using a natural experiment from 1984 in Denmark when the leave length was increased from 14......¤ect on childrens long-term cognitive outcomes....... to 20 weeks. Regression discontinuity design is used to identify the causal e¤ect of the reform. A population sample of children born in 1984 and a dataset with PISA-2000 scores are used for the analysis. Results indicate that increasing parents. access to birth-related leave has no measurable e...

  12. Comparisons between Arabidopsis thaliana and Drosophila melanogaster in relation to Coding and Noncoding Sequence Length and Gene Expression

    Directory of Open Access Journals (Sweden)

    Rachel Caldwell

    2015-01-01

    Full Text Available There is a continuing interest in the analysis of gene architecture and gene expression to determine the relationship that may exist. Advances in high-quality sequencing technologies and large-scale resource datasets have increased the understanding of relationships and cross-referencing of expression data to the large genome data. Although a negative correlation between expression level and gene (especially transcript length has been generally accepted, there have been some conflicting results arising from the literature concerning the impacts of different regions of genes, and the underlying reason is not well understood. The research aims to apply quantile regression techniques for statistical analysis of coding and noncoding sequence length and gene expression data in the plant, Arabidopsis thaliana, and fruit fly, Drosophila melanogaster, to determine if a relationship exists and if there is any variation or similarities between these species. The quantile regression analysis found that the coding sequence length and gene expression correlations varied, and similarities emerged for the noncoding sequence length (5′ and 3′ UTRs between animal and plant species. In conclusion, the information described in this study provides the basis for further exploration into gene regulation with regard to coding and noncoding sequence length.

  13. Scanning transmission x-ray microscopy of polymer nanoparticles: probing morphology on sub-10 nm length scales.

    Science.gov (United States)

    Burke, Kerry B; Stapleton, Andrew J; Vaughan, Ben; Zhou, Xiaojing; Kilcoyne, A L David; Belcher, Warwick J; Dastoor, Paul C

    2011-07-01

    Water-processable nanoparticle dispersions of semiconducting polymers offer an attractive approach to the fabrication of organic electronic devices since they offer: (1) control of nanoscale morphology and (2) environmentally friendly fabrication. Although the nature of phase segregation in these polymer nanoparticles is critical to device performance, to date there have been no techniques available to directly determine their intra-particle structure, which consequently has been poorly understood. Here, we present scanning transmission x-ray microscopy (STXM) compositional maps for nanoparticles fabricated from poly(9,9-dioctyl-fluorene-2,7-diyl-co-bis-N, N'-(4-butylphenyl)-bis-N, N'-phenyl-1,4-phenylenedi-amine) (PFB) and poly(9,9-dioctylfluorene-2,7-diyl-co-benzothiadiazole) (F8BT) 1:1 blend mixtures. The images show distinct phase segregation within the nanoparticles. The compositional data reveals that, within these nanoparticles, PFB and F8BT segregate into a core-shell morphology, with an F8BT-rich core and a PFB-rich shell. Structural modelling demonstrates that the STXM technique is capable of quantifying morphological features on a sub-10 nm length scale; below the spot size of the incident focused x-ray beam. These results have important implications for the development of water-based 'solar paints' fabricated from microemulsions of semiconducting polymers.

  14. Scanning transmission x-ray microscopy of polymer nanoparticles: probing morphology on sub-10 nm length scales

    Science.gov (United States)

    Burke, Kerry B.; Stapleton, Andrew J.; Vaughan, Ben; Zhou, Xiaojing; Kilcoyne, A. L. David; Belcher, Warwick J.; Dastoor, Paul C.

    2011-07-01

    Water-processable nanoparticle dispersions of semiconducting polymers offer an attractive approach to the fabrication of organic electronic devices since they offer: (1) control of nanoscale morphology and (2) environmentally friendly fabrication. Although the nature of phase segregation in these polymer nanoparticles is critical to device performance, to date there have been no techniques available to directly determine their intra-particle structure, which consequently has been poorly understood. Here, we present scanning transmission x-ray microscopy (STXM) compositional maps for nanoparticles fabricated from poly(9,9-dioctyl-fluorene-2,7-diyl-co-bis-N, N'-(4-butylphenyl)-bis-N, N'-phenyl-1,4-phenylenedi-amine) (PFB) and poly(9,9-dioctylfluorene-2,7-diyl-co-benzothiadiazole) (F8BT) 1:1 blend mixtures. The images show distinct phase segregation within the nanoparticles. The compositional data reveals that, within these nanoparticles, PFB and F8BT segregate into a core-shell morphology, with an F8BT-rich core and a PFB-rich shell. Structural modelling demonstrates that the STXM technique is capable of quantifying morphological features on a sub-10 nm length scale; below the spot size of the incident focused x-ray beam. These results have important implications for the development of water-based 'solar paints' fabricated from microemulsions of semiconducting polymers.

  15. Scanning transmission x-ray microscopy of polymer nanoparticles: probing morphology on sub-10 nm length scales

    International Nuclear Information System (INIS)

    Burke, Kerry B; Stapleton, Andrew J; Vaughan, Ben; Zhou Xiaojing; Belcher, Warwick J; Dastoor, Paul C; Kilcoyne, A L David

    2011-01-01

    Water-processable nanoparticle dispersions of semiconducting polymers offer an attractive approach to the fabrication of organic electronic devices since they offer: (1) control of nanoscale morphology and (2) environmentally friendly fabrication. Although the nature of phase segregation in these polymer nanoparticles is critical to device performance, to date there have been no techniques available to directly determine their intra-particle structure, which consequently has been poorly understood. Here, we present scanning transmission x-ray microscopy (STXM) compositional maps for nanoparticles fabricated from poly(9,9-dioctyl-fluorene-2,7-diyl-co-bis-N, N ' -(4-butylphenyl)-bis-N, N ' -phenyl-1,4-phenylenedi-amine) (PFB) and poly(9,9-dioctylfluorene-2,7-diyl-co-benzothiadiazole) (F8BT) 1:1 blend mixtures. The images show distinct phase segregation within the nanoparticles. The compositional data reveals that, within these nanoparticles, PFB and F8BT segregate into a core-shell morphology, with an F8BT-rich core and a PFB-rich shell. Structural modelling demonstrates that the STXM technique is capable of quantifying morphological features on a sub-10 nm length scale; below the spot size of the incident focused x-ray beam. These results have important implications for the development of water-based 'solar paints' fabricated from microemulsions of semiconducting polymers.

  16. Scanning transmission x-ray microscopy of polymer nanoparticles: probing morphology on sub-10 nm length scales

    Energy Technology Data Exchange (ETDEWEB)

    Burke, Kerry B; Stapleton, Andrew J; Vaughan, Ben; Zhou Xiaojing; Belcher, Warwick J; Dastoor, Paul C [Centre for Organic Electronics, University of Newcastle, Callaghan, NSW 2308 (Australia); Kilcoyne, A L David, E-mail: Paul.Dastoor@newcastle.edu.au [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2011-07-01

    Water-processable nanoparticle dispersions of semiconducting polymers offer an attractive approach to the fabrication of organic electronic devices since they offer: (1) control of nanoscale morphology and (2) environmentally friendly fabrication. Although the nature of phase segregation in these polymer nanoparticles is critical to device performance, to date there have been no techniques available to directly determine their intra-particle structure, which consequently has been poorly understood. Here, we present scanning transmission x-ray microscopy (STXM) compositional maps for nanoparticles fabricated from poly(9,9-dioctyl-fluorene-2,7-diyl-co-bis-N, N{sup '}-(4-butylphenyl)-bis-N, N{sup '}-phenyl-1,4-phenylenedi-amine) (PFB) and poly(9,9-dioctylfluorene-2,7-diyl-co-benzothiadiazole) (F8BT) 1:1 blend mixtures. The images show distinct phase segregation within the nanoparticles. The compositional data reveals that, within these nanoparticles, PFB and F8BT segregate into a core-shell morphology, with an F8BT-rich core and a PFB-rich shell. Structural modelling demonstrates that the STXM technique is capable of quantifying morphological features on a sub-10 nm length scale; below the spot size of the incident focused x-ray beam. These results have important implications for the development of water-based 'solar paints' fabricated from microemulsions of semiconducting polymers.

  17. Contact damage and fracture micromechanisms of multilayered TiN/CrN coatings at micro- and nano-length scales

    Energy Technology Data Exchange (ETDEWEB)

    Roa, J.J., E-mail: joan.josep.roa@upc.edu [CIEFMA — Departament de Ciència dels Materials i Eng. Metallúrgica, Universitat Politècnica de Catalunya, Avda. Diagonal 647, 08028 Barcelona (Spain); CRnE, Universitat Politècnica de Catalunya, C. Pasqual i Vila 15, 08028 Barcelona (Spain); Jiménez-Piqué, E. [CIEFMA — Departament de Ciència dels Materials i Eng. Metallúrgica, Universitat Politècnica de Catalunya, Avda. Diagonal 647, 08028 Barcelona (Spain); CRnE, Universitat Politècnica de Catalunya, C. Pasqual i Vila 15, 08028 Barcelona (Spain); Martínez, R. [Centro de Ingeniería Avanzada de Superfícies, Asociación de la Industria Navarra — AIN, Crta. Pamplona, 1, Edificio AIN, 31191 Cordovilla (Spain); Ramírez, G. [CIEFMA — Departament de Ciència dels Materials i Eng. Metallúrgica, Universitat Politècnica de Catalunya, Avda. Diagonal 647, 08028 Barcelona (Spain); Fundació CTM Centre Tecnològic, Avda. Bases de Manresa 1, 08243 Manresa (Spain); Tarragó, J.M. [CIEFMA — Departament de Ciència dels Materials i Eng. Metallúrgica, Universitat Politècnica de Catalunya, Avda. Diagonal 647, 08028 Barcelona (Spain); CRnE, Universitat Politècnica de Catalunya, C. Pasqual i Vila 15, 08028 Barcelona (Spain); and others

    2014-11-28

    In this study, systematic nanomechanical and micromechanical studies have been conducted in three multilayer TiN/CrN systems with different bilayer periods (8, 19 and 25 nm). Additionally, experimental work has been performed on corresponding TiN and CrN single layers, for comparison purposes. The investigation includes the use of different indenter tip geometries as well as contact loading conditions (i.e. indentation/scratch) such to induce different stress field and damage scenarios within the films. The surface and subsurface damage under the different indentation imprints and scratch tracks have been observed by atomic force microscopy, field emission scanning electron microscopy and focused ion beam. Multilayer TiN/CrN coated systems are found to exhibit higher adhesion strength (under sliding contact load) and cracking resistance (under spherical indentation) than those coated with reference TiN and CrN monolayers. The main reason behind these findings is the effective development of microstructurally-driven deformation and cracking resistant micromechanisms: rotation of columnar grains (and associated distortion of bilayer period) and crack deflection of interlayer thickness length scale, respectively. - Highlights: • Nanomechanical and micromechanical study in TiN/CrN systems • TiN/CrN coated systems exhibit higher adhesion strength and cracking resistance. • Main deformation and cracking micromechanisms: columnar grain rotation and crack deflection.

  18. Soft x-ray microscopy - a powerful analytical tool to image magnetism down to fundamental length and times scales

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Peter

    2008-08-01

    The magnetic properties of low dimensional solid state matter is of the utmost interest both scientifically as well as technologically. In addition to the charge of the electron which is the base for current electronics, by taking into account the spin degree of freedom in future spintronics applications open a new avenue. Progress towards a better physical understanding of the mechanism and principles involved as well as potential applications of nanomagnetic devices can only be achieved with advanced analytical tools. Soft X-ray microscopy providing a spatial resolution towards 10nm, a time resolution currently in the sub-ns regime and inherent elemental sensitivity is a very promising technique for that. This article reviews the recent achievements of magnetic soft X-ray microscopy by selected examples of spin torque phenomena, stochastical behavior on the nanoscale and spin dynamics in magnetic nanopatterns. The future potential with regard to addressing fundamental magnetic length and time scales, e.g. imaging fsec spin dynamics at upcoming X-ray sources is pointed out.

  19. Surface physicochemical properties at the micro and nano length scales: role on bacterial adhesion and Xylella fastidiosa biofilm development.

    Science.gov (United States)

    Lorite, Gabriela S; Janissen, Richard; Clerici, João H; Rodrigues, Carolina M; Tomaz, Juarez P; Mizaikoff, Boris; Kranz, Christine; de Souza, Alessandra A; Cotta, Mônica A

    2013-01-01

    The phytopathogen Xylella fastidiosa grows as a biofilm causing vascular occlusion and consequently nutrient and water stress in different plant hosts by adhesion on xylem vessel surfaces composed of cellulose, hemicellulose, pectin and proteins. Understanding the factors which influence bacterial adhesion and biofilm development is a key issue in identifying mechanisms for preventing biofilm formation in infected plants. In this study, we show that X. fastidiosa biofilm development and architecture correlate well with physicochemical surface properties after interaction with the culture medium. Different biotic and abiotic substrates such as silicon (Si) and derivatized cellulose films were studied. Both biofilms and substrates were characterized at the micro- and nanoscale, which corresponds to the actual bacterial cell and membrane/ protein length scales, respectively. Our experimental results clearly indicate that the presence of surfaces with different chemical composition affect X. fastidiosa behavior from the point of view of gene expression and adhesion functionality. Bacterial adhesion is facilitated on more hydrophilic surfaces with higher surface potentials; XadA1 adhesin reveals different strengths of interaction on these surfaces. Nonetheless, despite different architectural biofilm geometries and rates of development, the colonization process occurs on all investigated surfaces. Our results univocally support the hypothesis that different adhesion mechanisms are active along the biofilm life cycle representing an adaptation mechanism for variations on the specific xylem vessel composition, which the bacterium encounters within the infected plant.

  20. Oblique-Length Contraction Factor in the Special Theory of Relativity

    Directory of Open Access Journals (Sweden)

    Smarandache F.

    2013-01-01

    Full Text Available In this paper one generalizes the Lorentz Contraction Factor for the case when the lengths are moving at an oblique angle with respect to the motion direction. One shows that the angles of the moving relativistic objects are distorted.

  1. Relation Between Amoxicillin Concentration in Sputum of COPD Patients and Length of Hospitalization

    NARCIS (Netherlands)

    Brusse-Keizer, Marjolein; ten Bokum, Leonore; Movig, Kris; van der Valk, Paul; Kerstjens, Huib; van der Palen, Job; Hendrix, Ron

    Amoxicillin is a widely used antibiotic in COPD. Little is known about the transfer of amoxicillin into sputum of COPD patients. The objective was to investigate the relationship between the concentration of amoxicillin in sputum in hospitalized COPD patients and length of hospitalization. To be

  2. The Relation of Utterance Length to Grammatical Complexity in Normal and Language-Disordered Groups.

    Science.gov (United States)

    Scarborough, Hollis S.; And Others

    1991-01-01

    Examines mean length of utterance (MLU) in morphemes as a predictor of the grammatical complexity of the natural language corpora of normal preschoolers and of children and adolescents with delayed language, Fragile X Syndrome, Down Syndrome, and autism. (43 references) (GLR)

  3. Aerodynamic resistance of spruce forest stand in relation to roughness length and airflow

    Czech Academy of Sciences Publication Activity Database

    Hurtalová, T.; Matějka, F.; Rožnovský, J.; Janouš, Dalibor

    2003-01-01

    Roč. 33, č. 3 (2003), s. 147-160 ISSN 1335-2806 R&D Projects: GA ČR(CZ) GA526/03/1104 Keywords : aerodynamic resistance * spruce forest stand * roughness length Subject RIV: DG - Athmosphere Sciences, Meteorology

  4. Increasing the accuracy and precision of relative telomere length estimates by RT qPCR

    NARCIS (Netherlands)

    Eastwood, Justin R.; Mulder, Ellis; Verhulst, Simon; Peters, Anne

    As attrition of telomeres, DNA caps that protect chromosome integrity, is accelerated by various forms of stress, telomere length (TL) has been proposed as an indicator of lifetime accumulated stress. In ecological studies, it has been used to provide insights into ageing, life history trade-offs,

  5. [Changes in bone mineral density of postmenopausal women in relation to the menstrual cycle length].

    Science.gov (United States)

    Enchev, E; Dimitrakova, E

    2010-01-01

    There is a strong relationship between the age of menarche, the length of the menstrual cycle and menstrual bleeding and fracture risk in the postmenopausal period. Evaluation of the menstrual cycle length and lumbar bone mineral density in postmenopausal women. We investigated three groups of postmenopausal women (each - n = 50). The first group included women with menstrual duration of 27 days during reproductive age, the second group included postmenopausal women with menstrual duration of 28 days during the reproductive age, and the third group consisted of postmenopausal women with menstrual duration of 30 days during reproductive age. The average age of women was 58.80 +/- 0.94 y. in the first group, 60.36 +/- 5.12 y. in the second group and -61.84 +/- 0.80 y. in the third group. Age, age of menarche, number of childbirths, length of the menstrual cycle and menstrual bleeding, and lumbar bone density were assessed and registered for each woman. We used DXA in a anterior-posterior projection to assess the bone density of the lumbar spine; the obtained results are shown in gram/cm2. The women from the third group, with average menstrual cycle length of 30 days, reach menopause at a significantly later age, have longer menstrual cycle and shorter menstrual bleeding, and higher lumbar spine bone density, compared to the other two groups. The data from our research show that women with anamnesis for average normal menstrual cycle length of 30 days reach menopausal period at a significantly later age, have shorter menstrual bleeding, and higher lumbar spine bone density compared to those with shorter menstrual cycle duration (27 and 28 days).

  6. Large-scale collection and annotation of full-length enriched cDNAs from a model halophyte, Thellungiella halophila

    Directory of Open Access Journals (Sweden)

    Seki Motoaki

    2008-11-01

    Full Text Available Abstract Background Thellungiella halophila (also known as Thellungiella salsuginea is a model halophyte with a small plant size, short life cycle, and small genome. It easily undergoes genetic transformation by the floral dipping method used with its close relative, Arabidopsis thaliana. Thellungiella genes exhibit high sequence identity (approximately 90% at the cDNA level with Arabidopsis genes. Furthermore, Thellungiella not only shows tolerance to extreme salinity stress, but also to chilling, freezing, and ozone stress, supporting the use of Thellungiella as a good genomic resource in studies of abiotic stress tolerance. Results We constructed a full-length enriched Thellungiella (Shan Dong ecotype cDNA library from various tissues and whole plants subjected to environmental stresses, including high salinity, chilling, freezing, and abscisic acid treatment. We randomly selected about 20 000 clones and sequenced them from both ends to obtain a total of 35 171 sequences. CAP3 software was used to assemble the sequences and cluster them into 9569 nonredundant cDNA groups. We named these cDNAs "RTFL" (RIKEN Thellungiella Full-Length cDNAs. Information on functional domains and Gene Ontology (GO terms for the RTFL cDNAs were obtained using InterPro. The 8289 genes assigned to InterPro IDs were classified according to the GO terms using Plant GO Slim. Categorical comparison between the whole Arabidopsis genome and Thellungiella genes showing low identity to Arabidopsis genes revealed that the population of Thellungiella transport genes is approximately 1.5 times the size of the corresponding Arabidopsis genes. This suggests that these genes regulate a unique ion transportation system in Thellungiella. Conclusion As the number of Thellungiella halophila (Thellungiella salsuginea expressed sequence tags (ESTs was 9388 in July 2008, the number of ESTs has increased to approximately four times the original value as a result of this effort. Our

  7. Diffusion effects on volume-selective NMR at small length scales; Diffusionseffekte in volumenselektiver NMR auf kleinen Laengenskalen

    Energy Technology Data Exchange (ETDEWEB)

    Gaedke, Achim

    2009-01-21

    In this thesis, the interplay between diffusion and relaxation effects in spatially selective NMR experiments at short length scales is explored. This is especially relevant in the context of both conventional and mechanically detected MRI at (sub)micron resolution in biological specimens. Recent results on selectively excited very thin slices showed an in-slice-magnetization recovery orders of magnitude faster than the longitudinal relaxation time T1. However, those experiments were run on fully relaxed samples while MRI and especially mechanically detected NMR experiments are typically run in a periodic fashion with repetition times far below T1. The main purpose of this work therefore was to extend the study of the interplay between diffusion and longitudinal relaxation to periodic excitations. In some way, this is inverse phenomenon to the DESIRE (Diffusive Enhancement of SIgnal and REsolution) approach, proposed 1992 by Lauterbur. Experiments on periodically excited thin slices were carried out at a dedicated static field gradient cryomagnet with magnetic field gradients up to 180 T/m. In order to obtain plane slices, an appropriate isosurface of the gradient magnet had to be identified. It was found at a field of 3.8 T with a gradient of 73 T/m. In this field, slices down to a thickness of 3.2 {mu}m could be excited. The detection of the NMR signal was done using FIDs instead of echoes as the excitation bandwidth of those thin slices is sufficiently small to observe FIDs which are usually considered to be elusive to detection in such strong static field gradients. A simulation toolbox based on the full Bloch-Torrey-equation was developed to describe the excitation and the formation of NMR signals under those unusual conditions as well as the interplay of diffusion and magnetization recovery. Both the experiments and the simulations indicate that diffusion effects lead to a strongly enhanced magnetization modulation signal also under periodic excitation

  8. DISK GALAXY SCALING RELATIONS IN THE SFI++: INTRINSIC SCATTER AND APPLICATIONS

    International Nuclear Information System (INIS)

    Saintonge, Amelie; Spekkens, Kristine

    2011-01-01

    We study the scaling relations between the luminosities, sizes, and rotation velocities of disk galaxies in the SFI++, with a focus on the size-luminosity (RL) and size-rotation velocity (RV) relations. Using isophotal radii instead of disk scale lengths as a size indicator, we find relations that are significantly tighter than previously reported: the correlation coefficients of the template RL and RV relations are r = 0.97 and r= 0.85, respectively, which rival that of the more widely studied LV (Tully-Fisher) relation. The scatter in the SFI++ RL relation is 2.5-4 times smaller than previously reported for various samples, which we attribute to the reliability of isophotal radii relative to disk scale lengths. After carefully accounting for all measurement errors, our scaling relation error budgets are consistent with a constant intrinsic scatter in the LV and RV relations for velocity widths log W ∼> 2.4, with evidence for increasing intrinsic scatter below this threshold. The scatter in the RL relation is consistent with constant intrinsic scatter that is biased by incompleteness at the low-L end. Possible applications of the unprecedentedly tight SFI++ RV and RL relations are investigated. Just like the Tully-Fisher relation, the RV relation can be used as a distance indicator: we derive distances to galaxies with primary Cepheid distances that are accurate to 25%, and reverse the problem to measure a Hubble constant H 0 = 72 ± 7 km s -1 Mpc -1 . Combining the small intrinsic scatter of our RL relation (ε int = 0.034 ± 0.001log [h -1 kpc]) with a simple model for disk galaxy formation, we find an upper limit in the range of disk spin parameters that is a factor of ∼7 smaller than that of the halo spin parameters predicted by cosmological simulations. This likely implies that the halos hosting Sc galaxies have a much narrower distribution of spin parameters than previously thought.

  9. Prevalence of lattice degeneration and its relation to axial length in severe myopia.

    Science.gov (United States)

    Celorio, J M; Pruett, R C

    1991-01-15

    We studied 436 eyes of 218 patients with myopia of -6.00 diopters or more in both eyes. Of 218 patients, 72 (33.0%) had lattice degeneration of the retina. Among these 72 patients, lattice lesions were uniocular in 39 (54.2%) and binocular in 33 (45.8%). Of 105 males, 33 (31.4%) had lattice degeneration; of 113 females, 39 (34.5%) had lattice degeneration. Contrary to previously published data, we found an inverse relationship between axial length and the prevalence of lattice degeneration in severely myopic eyes. The greatest prevalence of lattice degeneration (63 of 154 eyes, 40.9%) was found in eyes with an axial length of 26.0 to 26.9 mm (-6.00 to -8.70 diopters), and the least prevalence of lattice degeneration (five of 71 eyes, 7.0%) was found in eyes with an axial length of 32.0 mm (-24.00 diopters) or greater. This may explain the observation that retinal detachment after cataract surgery has been noted more commonly among patients with moderate than severe myopia.

  10. Accessible length scale of the in-plane structure in polarized neutron off-specular and grazing-incidence small-angle scattering measurements

    Science.gov (United States)

    Maruyama, R.; Bigault, T.; Wildes, A. R.; Dewhurst, C. D.; Saerbeck, T.; Honecker, D.; Yamazaki, D.; Soyama, K.; Courtois, P.

    2017-06-01

    Polarized neutron off-specular and grazing-incidence small-angle scattering measurements are useful methods to investigate the in-plane structure and its correlation of layered systems. Although these measurements give information on complementary and overlapping length scale, the different characteristics between them need to be taken into account when performed. In this study, the difference in the accessible length scale of the in-plane structure, which is one of the most important characteristics, was discussed using an Fe/Si multilayer together with simulations based on the distorted wave Born approximation.

  11. Incontinence after primary repair of obstetric anal sphincter tears is related to relative length of reconstructed external sphincter

    DEFF Research Database (Denmark)

    Norderval, S; Røssaak, K.; Markskog, A

    2012-01-01

    To determine if anatomic primary repair with end-to-end reconstruction of the external anal sphincter (EAS) in its full length combined with separate repair of coexisting internal anal sphincter (IAS) tear, when present, results in less incontinence and better anal sphincter integrity compared wi...

  12. Commensurate scale relations: Precise tests of quantum chromodynamics without scale or scheme ambiguity

    International Nuclear Information System (INIS)

    Brodsky, S.J.; Lu, H.J.

    1994-10-01

    We derive commensurate scale relations which relate perturbatively calculable QCD observables to each other, including the annihilation ratio R e+ e - , the heavy quark potential, τ decay, and radiative corrections to structure function sum rules. For each such observable one can define an effective charge, such as α R (√s)/π ≡ R e+ e - (√s)/(3Σe q 2 )-1. The commensurate scale relation connecting the effective charges for observables A and B has the form α A (Q A ) α B (Q B )(1 + r A/Bπ / αB + hor-ellipsis), where the coefficient r A/B is independent of the number of flavors ∫ contributing to coupling renormalization, as in BLM scale-fixing. The ratio of scales Q A /Q B is unique at leading order and guarantees that the observables A and B pass through new quark thresholds at the same physical scale. In higher orders a different renormalization scale Q n* is assigned for each order n in the perturbative series such that the coefficients of the series are identical to that of a invariant theory. The commensurate scale relations and scales satisfy the renormalization group transitivity rule which ensures that predictions in PQCD are independent of the choice of an intermediate renormalization scheme C. In particular, scale-fixed predictions can be made without reference to theoretically constructed singular renormalization schemes such as MS. QCD can thus be tested in a new and precise way by checking that the effective charges of observables track both in their relative normalization and in their commensurate scale dependence. The commensurate scale relations which relate the radiative corrections to the annihilation ratio R e + e - to the radiative corrections for the Bjorken and Gross-Llewellyn Smith sum rules are particularly elegant and interesting

  13. North Atlantic Basin Tropical Cyclone Activity in Relation to Temperature and Decadal- Length Oscillation Patterns

    Science.gov (United States)

    Wilson, Robert M.

    2009-01-01

    Yearly frequencies of North Atlantic basin tropical cyclones, their locations of origin, peak wind speeds, average peak wind speeds, lowest pressures, and average lowest pressures for the interval 1950-2008 are examined. The effects of El Nino and La Nina on the tropical cyclone parametric values are investigated. Yearly and 10-year moving average (10-yma) values of tropical cyclone parameters are compared against those of temperature and decadal-length oscillation, employing both linear and bi-variate analysis, and first differences in the 10-yma are determined. Discussion of the 2009 North Atlantic basin hurricane season, updating earlier results, is given.

  14. Multiwalled carbon nanotubes for drug delivery: Efficiency related to length and incubation time.

    Science.gov (United States)

    Sciortino, Niccolò; Fedeli, Stefano; Paoli, Paolo; Brandi, Alberto; Chiarugi, Paola; Severi, Mirko; Cicchi, Stefano

    2017-04-15

    Batches of oxidized multiwalled carbon nanotubes differing in length were adopted to prepare two drug delivery systems (DDS) loaded with doxorubicin. The different internalization of the two batches, verified by atomic emission spectroscopy onto cell lysates, was also confirmed by the different toxicity of the same DDS loaded with doxorubicin. In vitro experiments evidenced, after 48h of incubation, the superior efficacy of the shortest nanotubes. However, upon prolonging the incubation time up to 72h the difference in efficiency was minimized due to the spontaneous release of doxorubicin by the non-internalized long nanotubes. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Non-Abelian gauge field theory in scale relativity

    International Nuclear Information System (INIS)

    Nottale, Laurent; Celerier, Marie-Noeelle; Lehner, Thierry

    2006-01-01

    Gauge field theory is developed in the framework of scale relativity. In this theory, space-time is described as a nondifferentiable continuum, which implies it is fractal, i.e., explicitly dependent on internal scale variables. Owing to the principle of relativity that has been extended to scales, these scale variables can themselves become functions of the space-time coordinates. Therefore, a coupling is expected between displacements in the fractal space-time and the transformations of these scale variables. In previous works, an Abelian gauge theory (electromagnetism) has been derived as a consequence of this coupling for global dilations and/or contractions. We consider here more general transformations of the scale variables by taking into account separate dilations for each of them, which yield non-Abelian gauge theories. We identify these transformations with the usual gauge transformations. The gauge fields naturally appear as a new geometric contribution to the total variation of the action involving these scale variables, while the gauge charges emerge as the generators of the scale transformation group. A generalized action is identified with the scale-relativistic invariant. The gauge charges are the conservative quantities, conjugates of the scale variables through the action, which find their origin in the symmetries of the ''scale-space.'' We thus found in a geometric way and recover the expression for the covariant derivative of gauge theory. Adding the requirement that under the scale transformations the fermion multiplets and the boson fields transform such that the derived Lagrangian remains invariant, we obtain gauge theories as a consequence of scale symmetries issued from a geometric space-time description

  16. Effect of polydispersity on the structure factor of a melt of binary multiblock copolymers with a two-length-scale macromolecular architecture

    NARCIS (Netherlands)

    Kuchanov, S.; Zharnikov, T.; Brinke, G. ten

    2011-01-01

    A theoretical study on the effect of polydispersity of two-length-scale binary multiblock copolymers on the shape of the structure factor is presented. A bifurcation diagram is constructed showing the partition of the parameter space into domains differing in the way in which the homogeneous melt

  17. Length of Residence and Vehicle Ownership in Relation to Physical Activity Among U.S. Immigrants.

    Science.gov (United States)

    Terasaki, Dale; Ornelas, India; Saelens, Brian

    2017-04-01

    Physical activity among U.S. immigrants over time is not well understood. Transportation may affect this trajectory. Using a survey of documented immigrants (N = 7240), we performed simple, then multivariable logistic regression to calculate ORs and 95 % CIs between length of residence (LOR) and both light-to-moderate (LPA) and vigorous (VPA) activity. We adjusted for demographic variables, then vehicle ownership to assess changes in ORs. Compared to new arrivals, all four LOR time-intervals were associated with lower odds of LPA and higher odds of VPA in simple analysis. All ORs for LPA remained significant after including demographics, but only one remained significant after adding vehicle ownership. Two ORs for VPA remained significant after including demographics and after adding vehicle ownership. Immigrants lower their light-to-moderate activity the longer they reside in the U.S., partly from substituting driving for walking. Efforts to maintain walking for transportation among immigrants are warranted.

  18. 'Length'at Length

    Indian Academy of Sciences (India)

    Admin

    He was interested to know how `large' is the set of numbers x for which the series is convergent. Here large refers to its length. But his set is not in the class ♢. Here is another problem discussed by Borel. Consider .... have an infinite collection of pairs of new shoes and want to choose one shoe from each pair. We have an ...

  19. Do Telomeres Adapt to Physiological Stress? Exploring the Effect of Exercise on Telomere Length and Telomere-Related Proteins

    Directory of Open Access Journals (Sweden)

    Andrew T. Ludlow

    2013-01-01

    Full Text Available Aging is associated with a tissue degeneration phenotype marked by a loss of tissue regenerative capacity. Regenerative capacity is dictated by environmental and genetic factors that govern the balance between damage and repair. The age-associated changes in the ability of tissues to replace lost or damaged cells is partly the cause of many age-related diseases such as Alzheimer's disease, cardiovascular disease, type II diabetes, and sarcopenia. A well-established marker of the aging process is the length of the protective cap at the ends of chromosomes, called telomeres. Telomeres shorten with each cell division and with increasing chronological age and short telomeres have been associated with a range of age-related diseases. Several studies have shown that chronic exposure to exercise (i.e., exercise training is associated with telomere length maintenance; however, recent evidence points out several controversial issues concerning tissue-specific telomere length responses. The goals of the review are to familiarize the reader with the current telomere dogma, review the literature exploring the interactions of exercise with telomere phenotypes, discuss the mechanistic research relating telomere dynamics to exercise stimuli, and finally propose future directions for work related to telomeres and physiological stress.

  20. Study of flow profile distortions and efficiency in counter pressure moderated partial filling micellar electrokinetic chromatography in relation to the relative buffer zone lengths.

    Science.gov (United States)

    Michalke, Daniela; Welsch, Thomas

    2002-06-25

    The influence of the relative buffer zone lengths on the efficiency was investigated in partial filling micellar electrokinetic chromatography using sodium dodecyl sulfate as separation additive. Varying relative zone lengths were obtained by applying identical initial separation zone lengths but different total lengths of the capillaries. Plate numbers of a homologous series of omega-phenylalcohols were measured to indicate the effect of both a changing relative zone length during the run and a counter pressure applied on the cathodic buffer reservoir. The magnitude and the course of these plate numbers are discussed on the basis of models for flow profile superposition and flow profile deformation which are caused by an intersegmental pressure arising at the boundary between the two buffer zones with different electroosmotic flow velocities. Calculation of the intersegmental pressure and of the resulting laminar flow components in the buffer zones on the basis of some equations for electroosmotic and hydrodynamic flow supported the interpretation that a long background buffer zone should be avoided

  1. Quantitative analysis of cone photoreceptor distribution and its relationship with axial length, age, and early age-related macular degeneration.

    Directory of Open Access Journals (Sweden)

    Ryo Obata

    Full Text Available PURPOSE: It has not been clarified whether early age-related macular degeneration (AMD is associated with cone photoreceptor distribution. We used adaptive optics fundus camera to examine cone photoreceptors in the macular area of aged patients and quantitatively analyzed its relationship between the presence of early AMD and cone distribution. METHODS: Sixty cases aged 50 or older were studied. The eyes were examined with funduscopy and spectral-domain optical coherence tomography to exclude the eyes with any abnormalities at two sites of measurement, 2° superior and 5° temporal to the fovea. High-resolution retinal images with cone photoreceptor mosaic were obtained with adaptive optics fundus camera (rtx1, Imagine Eyes, France. After adjusting for axial length, cone packing density was calculated and the relationship with age, axial length, or severity of early AMD based on the age-related eye disease study (AREDS classification was analyzed. RESULTS: Patient's age ranged from 50 to 77, and axial length from 21.7 to 27.5 mm. Mean density in metric units and that in angular units were 24,900 cells/mm2, 2,170 cells/deg2 at 2° superior, and 18,500 cells/mm2, 1,570 cels/deg2 at 5° temporal, respectively. Axial length was significantly correlated with the density calculated in metric units, but not with that in angular units. Age was significantly correlated with the density both in metric and angular units at 2° superior. There was no significant difference in the density in metric and angular units between the eyes with AREDS category one and those with categories two or three. CONCLUSION: Axial length and age were significantly correlated with parafoveal cone photoreceptor distribution. The results do not support that early AMD might influence cone photoreceptor density in the area without drusen or pigment abnormalities.

  2. Fundamental length

    International Nuclear Information System (INIS)

    Pradhan, T.

    1975-01-01

    The concept of fundamental length was first put forward by Heisenberg from purely dimensional reasons. From a study of the observed masses of the elementary particles known at that time, it is sumrised that this length should be of the order of magnitude 1 approximately 10 -13 cm. It was Heisenberg's belief that introduction of such a fundamental length would eliminate the divergence difficulties from relativistic quantum field theory by cutting off the high energy regions of the 'proper fields'. Since the divergence difficulties arise primarily due to infinite number of degrees of freedom, one simple remedy would be the introduction of a principle that limits these degrees of freedom by removing the effectiveness of the waves with a frequency exceeding a certain limit without destroying the relativistic invariance of the theory. The principle can be stated as follows: It is in principle impossible to invent an experiment of any kind that will permit a distintion between the positions of two particles at rest, the distance between which is below a certain limit. A more elegant way of introducing fundamental length into quantum theory is through commutation relations between two position operators. In quantum field theory such as quantum electrodynamics, it can be introduced through the commutation relation between two interpolating photon fields (vector potentials). (K.B.)

  3. Effect of artificial length scales in large eddy simulation of a neutral atmospheric boundary layer flow: A simple solution to log-layer mismatch

    Science.gov (United States)

    Chatterjee, Tanmoy; Peet, Yulia T.

    2017-07-01

    A large eddy simulation (LES) methodology coupled with near-wall modeling has been implemented in the current study for high Re neutral atmospheric boundary layer flows using an exponentially accurate spectral element method in an open-source research code Nek 5000. The effect of artificial length scales due to subgrid scale (SGS) and near wall modeling (NWM) on the scaling laws and structure of the inner and outer layer eddies is studied using varying SGS and NWM parameters in the spectral element framework. The study provides an understanding of the various length scales and dynamics of the eddies affected by the LES model and also the fundamental physics behind the inner and outer layer eddies which are responsible for the correct behavior of the mean statistics in accordance with the definition of equilibrium layers by Townsend. An economical and accurate LES model based on capturing the near wall coherent eddies has been designed, which is successful in eliminating the artificial length scale effects like the log-layer mismatch or the secondary peak generation in the streamwise variance.

  4. Scale relativity theory and integrative systems biology: 1. Founding principles and scale laws.

    Science.gov (United States)

    Auffray, Charles; Nottale, Laurent

    2008-05-01

    In these two companion papers, we provide an overview and a brief history of the multiple roots, current developments and recent advances of integrative systems biology and identify multiscale integration as its grand challenge. Then we introduce the fundamental principles and the successive steps that have been followed in the construction of the scale relativity theory, and discuss how scale laws of increasing complexity can be used to model and understand the behaviour of complex biological systems. In scale relativity theory, the geometry of space is considered to be continuous but non-differentiable, therefore fractal (i.e., explicitly scale-dependent). One writes the equations of motion in such a space as geodesics equations, under the constraint of the principle of relativity of all scales in nature. To this purpose, covariant derivatives are constructed that implement the various effects of the non-differentiable and fractal geometry. In this first review paper, the scale laws that describe the new dependence on resolutions of physical quantities are obtained as solutions of differential equations acting in the scale space. This leads to several possible levels of description for these laws, from the simplest scale invariant laws to generalized laws with variable fractal dimensions. Initial applications of these laws to the study of species evolution, embryogenesis and cell confinement are discussed.

  5. Scaling relations for galaxy clusters: Properties and evolution

    NARCIS (Netherlands)

    Giodini, S.; Lovisari, L.; Pointecouteau, E.; Ettori, S.; Reiprich, T.H.; Hoekstra, H.

    2013-01-01

    Well-calibrated scaling relations between the observable properties and the total masses of clusters of galaxies are important for understanding the physical processes that give rise to these relations. They are also a critical ingredient for studies that aim to constrain cosmological parameters

  6. Trade-offs in relative limb length among Peruvian children: extending the thrifty phenotype hypothesis to limb proportions.

    Directory of Open Access Journals (Sweden)

    Emma Pomeroy

    Full Text Available BACKGROUND AND METHODS: Both the concept of 'brain-sparing' growth and associations between relative lower limb length, childhood environment and adult disease risk are well established. Furthermore, tibia length is suggested to be particularly plastic under conditions of environmental stress. The mechanisms responsible are uncertain, but three hypotheses may be relevant. The 'thrifty phenotype' assumes that some components of growth are selectively sacrificed to preserve more critical outcomes, like the brain. The 'distal blood flow' hypothesis assumes that blood nutrients decline with distance from the heart, and hence may affect limbs in relation to basic body geometry. Temperature adaptation predicts a gradient of decreased size along the limbs reflecting decreasing tissue temperature/blood flow. We examined these questions by comparing the size of body segments among Peruvian children born and raised in differentially stressful environments. In a cross-sectional sample of children aged 6 months to 14 years (n = 447 we measured head circumference, head-trunk height, total upper and lower limb lengths, and zeugopod (ulna and tibia and autopod (hand and foot lengths. RESULTS: Highland children (exposed to greater stress had significantly shorter limbs and zeugopod and autopod elements than lowland children, while differences in head-trunk height were smaller. Zeugopod elements appeared most sensitive to environmental conditions, as they were relatively shorter among highland children than their respective autopod elements. DISCUSSION: The results suggest that functional traits (hand, foot, and head may be partially protected at the expense of the tibia and ulna. The results do not fit the predictions of the distal blood flow and temperature adaptation models as explanations for relative limb segment growth under stress conditions. Rather, our data support the extension of the thrifty phenotype hypothesis to limb growth, and suggest that

  7. Relative blood loss and operative time can predict length of stay following orthognathic surgery.

    Science.gov (United States)

    Andersen, K; Thastum, M; Nørholt, S E; Blomlöf, J

    2016-10-01

    The aim of this study was to investigate the length of stay (LOS) following orthognathic surgery and thereby to establish a benchmark. The secondary aim was to identify predictors of postoperative LOS following orthognathic surgery. Patients were treated consecutively during the period 2010 to 2012. Inclusion criteria were (1) patient age ≥18 years, and (2) surgery involving a three-piece Le Fort I osteotomy, or a bilateral sagittal split osteotomy (BSSO), or bimaxillary surgery. A total of 335 patients were included. The following data were recorded: height, weight, body mass index (BMI), age, sex, operative time, intraoperative blood loss, and type of surgery. LOS was defined as the duration of time from date of surgery to date of discharge. The average LOS was 1.3 days following Le Fort I osteotomy, 1.3 days following BSSO, and 1.8 days following bimaxillary surgery. In the multivariate regression model (R(2)=0.11), predictors of a prolonged LOS were operative time (POral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  8. Planck-scale-modified dispersion relations in FRW spacetime

    Science.gov (United States)

    Rosati, Giacomo; Amelino-Camelia, Giovanni; Marcianò, Antonino; Matassa, Marco

    2015-12-01

    In recent years, Planck-scale modifications of the dispersion relation have been attracting increasing interest also from the viewpoint of possible applications in astrophysics and cosmology, where spacetime curvature cannot be neglected. Nonetheless, the interplay between Planck-scale effects and spacetime curvature is still poorly understood, particularly in cases where curvature is not constant. These challenges have been so far postponed by relying on an ansatz, first introduced by Jacob and Piran. We propose here a general strategy of analysis of the effects of modifications of the dispersion relation in Friedmann-Robertson-Walker spacetimes, applicable both to cases where the relativistic equivalence of frames is spoiled ("preferred-frame scenarios") and to the alternative possibility of "DSR-relativistic theories," theories that are fully relativistic but with relativistic laws deformed so that the modified dispersion relation is observer independent. We show that the Jacob-Piran ansatz implicitly assumes that spacetime translations are not affected by the Planck scale, while under rather general conditions, the same Planck-scale quantum-spacetime structures producing modifications of the dispersion relation also affect translations. Through the explicit analysis of one of the effects produced by modifications of the dispersion relation, an effect amounting to Planck-scale corrections to travel times, we show that our concerns are not merely conceptual but rather can have significant quantitative implications.

  9. An allometric scaling relation based on logistic growth of cities

    International Nuclear Information System (INIS)

    Chen, Yanguang

    2014-01-01

    Highlights: • An allometric scaling based on logistic process can be used to model urban growth. • The traditional allometry is based on exponential growth instead of logistic growth. • The exponential allometry represents a local scaling of urban growth. • The logistic allometry represents a global scaling of urban growth. • The exponential allometry is an approximation relation of the logistic allometry. - Abstract: The relationships between urban area and population size have been empirically demonstrated to follow the scaling law of allometric growth. This allometric scaling is based on exponential growth of city size and can be termed “exponential allometry”, which is associated with the concepts of fractals. However, both city population and urban area comply with the course of logistic growth rather than exponential growth. In this paper, I will present a new allometric scaling based on logistic growth to solve the above mentioned problem. The logistic growth is a process of replacement dynamics. Defining a pair of replacement quotients as new measurements, which are functions of urban area and population, we can derive an allometric scaling relation from the logistic processes of urban growth, which can be termed “logistic allometry”. The exponential allometric relation between urban area and population is the approximate expression of the logistic allometric equation when the city size is not large enough. The proper range of the allometric scaling exponent value is reconsidered through the logistic process. Then, a medium-sized city of Henan Province, China, is employed as an example to validate the new allometric relation. The logistic allometry is helpful for further understanding the fractal property and self-organized process of urban evolution in the right perspective

  10. Current increment of tunnel field-effect transistor using InGaAs nanowire/Si heterojunction by scaling of channel length

    OpenAIRE

    Tomioka, Katsuhiro; Fukui, Takashi

    2014-01-01

    We report on a fabrication of tunnel field-effect transistors using InGaAs nanowire/Si heterojunctions and the characterization of scaling of channel lengths. The devices consisted of single InGaAs nanowires with a diameter of 30 nm grown on p-type Si(111) substrates. The switch demonstrated steep subthreshold-slope (30 mV/decade) at drain-source voltage (V-DS) of 0.10 V. Also, pinch-off behavior appeared at moderately low VDS, below 0.10 V. Reducing the channel length of the transistors atta...

  11. Comparing relative abundance, lengths, and habitat of temperate reef fishes using simultaneous underwater visual census, video, and trap sampling

    KAUST Repository

    Bacheler, NM

    2017-04-28

    Unbiased counts of individuals or species are often impossible given the prevalence of cryptic or mobile species. We used 77 simultaneous multi-gear deployments to make inferences about relative abundance, diversity, length composition, and habitat of the reef fish community along the southeastern US Atlantic coast. In total, 117 taxa were observed by underwater visual census (UVC), stationary video, and chevron fish traps, with more taxa being observed by UVC (100) than video (82) or traps (20). Frequency of occurrence of focal species was similar among all sampling approaches for tomtate Haemulon aurolineatum and black sea bass Centropristis striata, higher for UVC and video compared to traps for red snapper Lutjanus campechanus, vermilion snapper Rhomboplites aurorubens, and gray triggerfish Balistes capriscus, and higher for UVC compared to video or traps for gray snapper L. griseus and lionfish Pterois spp. For 6 of 7 focal species, correlations of relative abundance among gears were strongest between UVC and video, but there was substantial variability among species. The number of recorded species between UVC and video was correlated (ρ = 0.59), but relationships between traps and the other 2 methods were weaker. Lengths of fish visually estimated by UVC were similar to lengths of fish caught in traps, as were habitat characterizations from UVC and video. No gear provided a complete census for any species in our study, suggesting that analytical methods accounting for imperfect detection are necessary to make unbiased inferences about fish abundance.

  12. Relatively scaled ECE temperature profiles of KSTAR plasmas

    International Nuclear Information System (INIS)

    Choi, M. J.; Yun, G. S.; Park, H. K.; Jeon, Y. M.; Jeong, S. H.

    2010-01-01

    A scheme to obtain relatively scaled profiles of electron cyclotron emission (ECE) temperature directly from uncalibrated raw radiometer data is proposed and has been tested for the 2009 campaign KSTAR plasmas. The proposed method utilizes a position controlled system to move the plasma adiabatically and compares ECE radiometer channels at the same relative radial positions assuming the profile consistency during the adiabatic change. This scaling method is an alternative solution when an absolute calibration is unreliable or too time consuming. The application to the two dimensional ECE imaging data, wherein calibration is extremely difficult, may also prove to be useful.

  13. Confirmation of general relativity on large scales from weak lensing and galaxy velocities.

    Science.gov (United States)

    Reyes, Reinabelle; Mandelbaum, Rachel; Seljak, Uros; Baldauf, Tobias; Gunn, James E; Lombriser, Lucas; Smith, Robert E

    2010-03-11

    Although general relativity underlies modern cosmology, its applicability on cosmological length scales has yet to be stringently tested. Such a test has recently been proposed, using a quantity, E(G), that combines measures of large-scale gravitational lensing, galaxy clustering and structure growth rate. The combination is insensitive to 'galaxy bias' (the difference between the clustering of visible galaxies and invisible dark matter) and is thus robust to the uncertainty in this parameter. Modified theories of gravity generally predict values of E(G) different from the general relativistic prediction because, in these theories, the 'gravitational slip' (the difference between the two potentials that describe perturbations in the gravitational metric) is non-zero, which leads to changes in the growth of structure and the strength of the gravitational lensing effect. Here we report that E(G) = 0.39 +/- 0.06 on length scales of tens of megaparsecs, in agreement with the general relativistic prediction of E(G) approximately 0.4. The measured value excludes a model within the tensor-vector-scalar gravity theory, which modifies both Newtonian and Einstein gravity. However, the relatively large uncertainty still permits models within f(R) theory, which is an extension of general relativity. A fivefold decrease in uncertainty is needed to rule out these models.

  14. Development of Lab-to-Fab Production Equipment Across Several Length Scales for Printed Energy Technologies, Including Solar Cells

    DEFF Research Database (Denmark)

    Hösel, Markus; Dam, Henrik Friis; Krebs, Frederik C

    2015-01-01

    We describe and review how the scaling of printed energy technologies not only requires scaling of the input materials but also the machinery used in the processes. The general consensus that ultrafast processing of technologies with large energy capacity can only be realized using roll-to-roll m......We describe and review how the scaling of printed energy technologies not only requires scaling of the input materials but also the machinery used in the processes. The general consensus that ultrafast processing of technologies with large energy capacity can only be realized using roll...... the lower end of the industrial scale. The machinery bridges the gap through firstly achieving improved ink efficiency without surface contact, followed by better ink efficiency at higher speeds, and finally large-area processing at high speed with very high ink efficiency....

  15. Violence-Related Attitudes and Beliefs: Scale Construction and Psychometrics

    Science.gov (United States)

    Brand, Pamela A.; Anastasio, Phyllis A.

    2006-01-01

    The 50-item Violence-Related Attitudes and Beliefs Scale (V-RABS) includes three subscales measuring possible causes of violent behavior (environmental influences, biological influences, and mental illness) and four subscales assessing possible controls of violent behavior (death penalty, punishment, prevention, and catharsis). Each subscale…

  16. Work Related Injuries and Associated Factors among Small Scale ...

    African Journals Online (AJOL)

    user

    significantly associated factors with occupational injury. Conclusion: Work-related injuries were high among small scale industry workers in the studied area. Cigarette smoking, alcohol consumption, working for more than 8 hours and working at night had high odds of occupational injuries. Use of PPE and occupation health ...

  17. Work related injuries and associated factors among small scale ...

    African Journals Online (AJOL)

    Objective: This study aims to assess the magnitude of work related injury and associated factors among small scale industrial workers in Mizan-Aman town, Bench Maji Zone, Southwest Ethiopia. Method: A cross-sectional study design was conducted from February to May, 2016. Data was collected using a structured face to ...

  18. DMSA scan nomograms for renal length and area: Related to patient age and to body weight, height or surface area

    International Nuclear Information System (INIS)

    Hassan, I.M.; Que, L.; Rutland, M.D.

    2002-01-01

    Aim: To create nomograms for renal size as measured from DMSA renal studies, and to test the nomograms for their ability to separate normal from abnormal kidneys. Method: Renal length was measured from posterior oblique views and renal area from posterior views. Results from 253 patients with bilateral normal kidneys were used to create nomograms for renal size relative to patient age, body height, weight or body surface area (BSA). The nomograms enclosed 95% of the normal kidneys, thus indicating the range for 95% confidence limits, and hence the specificity. Each nomogram was then tested against 46 hypertrophied kidneys and 46 damaged kidneys. Results: The results from nomograms of renal length and renal area, compared to age, body height, body weight and BSA are presented. For each nomogram, the range is presented as a fraction of the mean value, and the number of abnormal kidneys (hypertrophied or damaged) outside the normal range is presented as a percentage (indicating the sensitivity). Conclusion: Renal Area was no better than renal length for detecting abnormal kidneys. Patient age was the least useful method of normalisation. BSA normalisation produced the best results most frequently (narrower ranges and highest detection of abnormal kidneys)

  19. Coupling of relative intensity noise and pathlength noise to the length measurement in the optical metrology system of LISA Pathfinder

    Science.gov (United States)

    Wittchen, Andreas; the LPF Collaboration

    2017-05-01

    LISA Pathfinder is a technology demonstration mission for the space-based gravitational wave observatory, LISA. It demonstrated that the performance requirements for the interferometric measurement of two test masses in free fall can be met. An important part of the data analysis is to identify the limiting noise sources. [1] This measurement is performed with heterodyne interferometry. The performance of this optical metrology system (OMS) at high frequencies is limited by sensing noise. One such noise source is Relative Intensity Noise (RIN). RIN is a property of the laser, and the photodiode current generated by the interferometer signal contains frequency dependant RIN. From this electric signal the phasemeter calculates the phase change and laser power, and the coupling of RIN into the measurement signal depends on the noise frequency. RIN at DC, at the heterodyne frequency and at two times the heterodyne frequency couples into the phase. Another important noise at high frequencies is path length noise. To reduce the impact this noise is suppressed with a control loop. Path length noise not suppressed will couple directly into the length measurement. The subtraction techniques of both noise sources depend on the phase difference between the reference signal and the measurement signal, and thus on the test mass position. During normal operations we position the test mass at the interferometric zero, which is optimal for noise subtraction purposes. This paper will show results from an in-flight experiment where the test mass position was changed to make the position dependant noise visible.

  20. Longer wings for faster springs - wing length relates to spring phenology in a long-distance migrant across its range.

    Science.gov (United States)

    Hahn, Steffen; Korner-Nievergelt, Fränzi; Emmenegger, Tamara; Amrhein, Valentin; Csörgő, Tibor; Gursoy, Arzu; Ilieva, Mihaela; Kverek, Pavel; Pérez-Tris, Javier; Pirrello, Simone; Zehtindjiev, Pavel; Salewski, Volker

    2016-01-01

    In migratory birds, morphological adaptations for efficient migratory flight often oppose morphological adaptations for efficient behavior during resident periods. This includes adaptations in wing shape for either flying long distances or foraging in the vegetation and in climate-driven variation of body size. In addition, the timing of migratory flights and particularly the timely arrival at local breeding sites is crucial because fitness prospects depend on site-specific phenology. Thus, adaptations for efficient long-distance flights might be also related to conditions at destination areas. For an obligatory long-distance migrant, the common nightingale, we verified that wing length as the aerodynamically important trait, but not structural body size increased from the western to the eastern parts of the species range. In contrast with expectation from aerodynamic theory, however, wing length did not increase with increasing migration distances. Instead, wing length was associated with the phenology at breeding destinations, namely the speed of local spring green-up. We argue that longer wings are beneficial for adjusting migration speed to local conditions for birds breeding in habitats with fast spring green-up and thus short optimal arrival periods. We suggest that the speed of spring green-up at breeding sites is a fundamental variable determining the timing of migration that fine tune phenotypes in migrants across their range.

  1. Relative Leukocyte Telomere Length, Hematological Parameters and Anemia - Data from the Berlin Aging Study II (BASE-II).

    Science.gov (United States)

    Meyer, Antje; Salewsky, Bastian; Buchmann, Nikolaus; Steinhagen-Thiessen, Elisabeth; Demuth, Ilja

    2016-01-01

    The length of the chromosome ends, telomeres, is widely accepted as a biomarker of aging. However, the dynamic of the relationship between telomere length and hematopoietic parameters in the normal aging process, which is of particular interest with respect to age-related anemia, is not well understood. We have analyzed the relationship between relative leukocyte telomere length (rLTL) and several hematological parameters in the older group of the Berlin Aging Study II (BASE-II) participants. This paper also compares rLTL between both BASE-II age groups (22-37 and 60-83 years). Genomic DNA was extracted from peripheral blood leukocytes of BASE-II participants and used to determine rLTL by a quantitative PCR protocol. Standard methods were used to determine blood parameters, and the WHO criteria were used to identify anemic participants. Telomere length data were available for 444 younger participants (28.4 ± 3.1 years old; 52% women) and 1,460 older participants (68.2 ± 3.7 years old; 49.4% women). rLTL was significantly shorter in BASE-II participants of the older group (p = 3.7 × 10-12) and in women (p = 4.2 × 10-31). rLTL of older men exhibited a statistically significant, positive partial correlation with mean corpuscular hemoglobin (MCH; p = 0.012) and MCH concentration (p = 0.002). While these correlations were only observed in men, the rLTL of older women was negatively correlated with the number of thrombocytes (p = 0.015) in the same type of analysis. Among all older participants, 6% met the criteria to be categorized as 'anemic'; however, there was no association between anemia and rLTL. In the present study, we have detected isolated correlations between rLTL and hematological parameters; however, in all cases, rLTL explained only a small part of the variation of the analyzed parameters. In disagreement with some other studies showing similar data, we interpret the association between rLTL and some of the hematological parameters studied here to be

  2. Leukocyte Telomere Length, Breast Cancer Risk in the Offspring: The Relations with Father’s Age at Birth

    OpenAIRE

    Arbeev, Konstantin G.; Hunt, Steven C.; Kimura, Masayuki; Aviv, Abraham; Yashin, Anatoliy I.

    2011-01-01

    Recent studies have reported that leukocyte telomere length (LTL) is longer in offspring of older fathers. Longer telomeres might increase cancer risk. We examined the relation of father’s age at the birth of the offspring (FAB) with LTL in the offspring in 2177 participants of the Family Heart Study and the probability of developing breast cancer in 1405 women from the Framingham Heart Study (offspring cohort). For each year of increase in FAB (adjusted for mother’s age at birth), LTLs in th...

  3. Leukocyte telomere length is associated with advanced age-related macular degeneration in the Han Chinese population.

    Science.gov (United States)

    Weng, Xiaoling; Zhang, Hong; Kan, Mengyuan; Ye, Junyi; Liu, Fatao; Wang, Ting; Deng, Jiaying; Tan, Yanfang; He, Lin; Liu, Yun

    2015-09-01

    Telomeres located at the ends of chromosomes are involved in genomic stability and play a key role in various cancers and age-related diseases. Age-related macular degeneration (AMD) is a late-onset, age-associated progressive neurodegenerative disease, which includes the geographic atrophy (GA) subtype and the choroidal neovascularization (CNV) subtype. To better understand how leukocyte telomere length (LTL) is related to AMD, we conducted an association study in 197 AMD patients and 259 healthy controls using the established quantitative PCR technique. Logistic regression was performed to evaluate the association of LTL and AMD with the age-adjusted ratio of the telomere length to the copy number of a single-copy gene (T/S). Notably, we found a significant association between AMD and LTL (OR=2.24; 95% CI=1.68-3.07; P=0.0001) after adjusting for age and sex. Furthermore, the results showed a strongly significant association between the GA subtype and the LTL (OR=4.81; 95% CI=3.15-7.82; P=0.0001) after adjusting for age and sex. Our findings provide evidence of the role that LTL plays in the pathological mechanisms of AMD, mainly in the GA subgroup but not the CNV subgroup. Copyright © 2015. Published by Elsevier Inc.

  4. The sandpile revisited: computer assisted determination of constitutive relations and the breaking of scaling.

    Science.gov (United States)

    Hentschel, H George E; Jaiswal, Prabhat K; Mondal, Chandana; Procaccia, Itamar; Zylberg, Jacques

    2017-07-26

    We revisit the problem of the stress distribution in a frictional sandpile with both normal and tangential (frictional) inter-granular forces, under gravity, equipped with a new numerical method of generating such assemblies. Numerical simulations allow a determination of the spatial dependence of all the components of the stress field, principle stress axis, angle of repose, as a function of systems size, the coefficient of static friction and the frictional interaction with the bottom surface. We compare these results with the predictions of a theory based on continuum equilibrium mechanics. Basic to the theory of sandpiles are assumptions about the form of scaling solutions and constitutive relations for cohesive-less hard grains for which no typical scale is available. We find that these constitutive relations must be modified; moreover for smaller friction coefficients and smaller piles these scaling assumptions break down in the bulk of the sandpile due to the presence of length scales that must be carefully identified. Fortunately, for larger friction coefficient and for larger piles the breaking of scaling is weak in the bulk, allowing an approximate analytic theory which agrees well with the observations. After identifying the crucial scale, triggering the breaking of scaling, we provide a predictive theory to when scaling solutions are expected to break down. At the bottom of the pile the scaling assumption breaks always, due to the different interactions with the bottom surface. The consequences for measurable quantities like the pressure distribution and shear stress at the bottom of the pile are discussed. For example one can have a transition from no dip in the base-pressure to a dip at the center of the pile as friction increases.

  5. Life expectancy: complex measures of the length and the health related quality of life

    Directory of Open Access Journals (Sweden)

    Daniele Spizzichino

    2008-06-01

    years lived are potentially independent from increase in health status of the population. Quantity and quality of live are not anymore strictly related, then a higher quantity of life does not equate to a better quality of life. For this reason are used health expectancies measures that are very useful morbidity-mortality indicators able to summarize information on quantity and quality of the years lived.

  6. Length-scale dependent microalloying effects on precipitation behaviors and mechanical properties of Al–Cu alloys with minor Sc addition

    International Nuclear Information System (INIS)

    Jiang, L.; Li, J.K.; Liu, G.; Wang, R.H.; Chen, B.A.; Zhang, J.Y.; Sun, J.; Yang, M.X.; Yang, G.; Yang, J.; Cao, X.Z.

    2015-01-01

    Heat-treatable Al alloys containing Al–2.5 wt% Cu (Al–Cu) and Al–2.5 wt% Cu–0.3 wt% Sc (Al–Cu–Sc) with different grain length scales, i.e., average grain size >10 μm ( defined coarse grained, CG), 1–2 μm (fine grained, FG), and <1 μm (ultrafine grained, UFG), were prepared by equal-channel angular pressing (ECAP). The length scale and Sc microalloying effects and their interplay on the precipitation behavior and mechanical properties of the Al–Cu alloys were systematically investigated. In the Al–Cu alloys, intergranular θ-Al 2 Cu precipitation gradually dominated by sacrificing the intragranular θ′-Al 2 Cu precipitation with reducing the length scale. Especially in the UFG regime, only intergranular θ-Al 2 Cu particles were precipitated and intragranular θ′-Al 2 Cu precipitation was completely disappeared. This led to a remarkable reduction in yield strength and ductility due to insufficient dislocation storage capacity. The minor Sc addition resulted in a microalloying effect in the Al–Cu alloy, which, however, is strongly dependent on the length scale. The smaller is the grain size, the more active is the microalloying effect that promotes the intragranular precipitation while reduces the intergranular precipitation. Correspondingly, compared with their Sc-free counterparts, the yield strength of post-aged CG, FG, and UFG Al–Cu alloys with Sc addition increased by ~36 MPa, ~56 MPa, and ~150 MPa, simultaneously in tensile elongation by ~20%, ~30%, and 280%, respectively. The grain size-induced evolutions in vacancy concentration/distribution and number density of vacancy-solute/solute–solute clusters and their influences on precipitation nucleation and kinetics have been comprehensively considered to rationalize the length scale-dependent Sc microalloying mechanisms using positron annihilation lifetime spectrum and three dimension atom probe. The increase in ductility was analyzed in the light of Sc microalloying effect and the

  7. Length-scale dependent microalloying effects on precipitation behaviors and mechanical properties of Al–Cu alloys with minor Sc addition

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, L.; Li, J.K. [State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Liu, G., E-mail: lgsammer@mail.xjtu.edu.cn [State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Wang, R.H. [School of Materials Science and Engineering, Xi' an University of Technology, Xi' an 710048 (China); Chen, B.A.; Zhang, J.Y. [State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Sun, J., E-mail: junsun@mail.xjtu.edu.cn [State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Yang, M.X.; Yang, G. [Central Iron and Steel Research Institute, Beijing 100081 (China); Yang, J.; Cao, X.Z. [Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2015-06-18

    Heat-treatable Al alloys containing Al–2.5 wt% Cu (Al–Cu) and Al–2.5 wt% Cu–0.3 wt% Sc (Al–Cu–Sc) with different grain length scales, i.e., average grain size >10 μm ( defined coarse grained, CG), 1–2 μm (fine grained, FG), and <1 μm (ultrafine grained, UFG), were prepared by equal-channel angular pressing (ECAP). The length scale and Sc microalloying effects and their interplay on the precipitation behavior and mechanical properties of the Al–Cu alloys were systematically investigated. In the Al–Cu alloys, intergranular θ-Al{sub 2}Cu precipitation gradually dominated by sacrificing the intragranular θ′-Al{sub 2}Cu precipitation with reducing the length scale. Especially in the UFG regime, only intergranular θ-Al{sub 2}Cu particles were precipitated and intragranular θ′-Al{sub 2}Cu precipitation was completely disappeared. This led to a remarkable reduction in yield strength and ductility due to insufficient dislocation storage capacity. The minor Sc addition resulted in a microalloying effect in the Al–Cu alloy, which, however, is strongly dependent on the length scale. The smaller is the grain size, the more active is the microalloying effect that promotes the intragranular precipitation while reduces the intergranular precipitation. Correspondingly, compared with their Sc-free counterparts, the yield strength of post-aged CG, FG, and UFG Al–Cu alloys with Sc addition increased by ~36 MPa, ~56 MPa, and ~150 MPa, simultaneously in tensile elongation by ~20%, ~30%, and 280%, respectively. The grain size-induced evolutions in vacancy concentration/distribution and number density of vacancy-solute/solute–solute clusters and their influences on precipitation nucleation and kinetics have been comprehensively considered to rationalize the length scale-dependent Sc microalloying mechanisms using positron annihilation lifetime spectrum and three dimension atom probe. The increase in ductility was analyzed in the light of Sc microalloying

  8. Chronic Hepatitis B Virus Infection: The Relation between Hepatitis B Antigen Expression, Telomere Length, Senescence, Inflammation and Fibrosis.

    Directory of Open Access Journals (Sweden)

    Phaedra M Tachtatzis

    Full Text Available Chronic Hepatitis B virus (HBV infection can lead to the development of chronic hepatitis, cirrhosis and hepatocellular carcinoma. We hypothesized that HBV might accelerate hepatocyte ageing and investigated the effect of HBV on hepatocyte cell cycle state and biological age. We also investigated the relation between inflammation, fibrosis and cell cycle phase.Liver samples from patients with chronic HBV (n = 91, normal liver (n = 55 and regenerating liver (n = 15 were studied. Immunohistochemistry for cell cycle phase markers and HBV antigens was used to determine host cell cycle phase. Hepatocyte-specific telomere length was evaluated by quantitative fluorescent in-situ hybridization (Q-FISH in conjunction with hepatocyte nuclear area and HBV antigen expression. The effects of induced cell cycle arrest and induced cellular senescence on HBV production were assessed in vitro.13.7% hepatocytes in chronic HBV had entered cell cycle, but expression of markers for S, G2 and M phase was low compared with regenerating liver. Hepatocyte p21 expression was increased (10.9% in chronic HBV and correlated with liver fibrosis. Mean telomere length was reduced in chronic HBV compared to normal. However, within HBV-affected livers, hepatocytes expressing HBV antigens had longer telomeres. Telomere length declined and hepatocyte nuclear size increased as HBV core antigen (HBcAg expression shifted from the nucleus to cytoplasm. Nuclear co-expression of HBcAg and p21 was not observed. Cell cycle arrest induced in vitro was associated with increased HBV production, in contrast to in vitro induction of cellular senescence, which had no effect.Chronic HBV infection was associated with hepatocyte G1 cell cycle arrest and accelerated hepatocyte ageing, implying that HBV induced cellular senescence. However, HBV replication was confined to biologically younger hepatocytes. Changes in the cellular location of HBcAg may be related to the onset of cellular senescence.

  9. Implicit Priors in Galaxy Cluster Mass and Scaling Relation Determinations

    Science.gov (United States)

    Mantz, A.; Allen, S. W.

    2011-01-01

    Deriving the total masses of galaxy clusters from observations of the intracluster medium (ICM) generally requires some prior information, in addition to the assumptions of hydrostatic equilibrium and spherical symmetry. Often, this information takes the form of particular parametrized functions used to describe the cluster gas density and temperature profiles. In this paper, we investigate the implicit priors on hydrostatic masses that result from this fully parametric approach, and the implications of such priors for scaling relations formed from those masses. We show that the application of such fully parametric models of the ICM naturally imposes a prior on the slopes of the derived scaling relations, favoring the self-similar model, and argue that this prior may be influential in practice. In contrast, this bias does not exist for techniques which adopt an explicit prior on the form of the mass profile but describe the ICM non-parametrically. Constraints on the slope of the cluster mass-temperature relation in the literature show a separation based the approach employed, with the results from fully parametric ICM modeling clustering nearer the self-similar value. Given that a primary goal of scaling relation analyses is to test the self-similar model, the application of methods subject to strong, implicit priors should be avoided. Alternative methods and best practices are discussed.

  10. Surface Rupture Effects on Earthquake Moment-Area Scaling Relations

    Science.gov (United States)

    Luo, Yingdi; Ampuero, Jean-Paul; Miyakoshi, Ken; Irikura, Kojiro

    2017-09-01

    Empirical earthquake scaling relations play a central role in fundamental studies of earthquake physics and in current practice of earthquake hazard assessment, and are being refined by advances in earthquake source analysis. A scaling relation between seismic moment ( M 0) and rupture area ( A) currently in use for ground motion prediction in Japan features a transition regime of the form M 0- A 2, between the well-recognized small (self-similar) and very large (W-model) earthquake regimes, which has counter-intuitive attributes and uncertain theoretical underpinnings. Here, we investigate the mechanical origin of this transition regime via earthquake cycle simulations, analytical dislocation models and numerical crack models on strike-slip faults. We find that, even if stress drop is assumed constant, the properties of the transition regime are controlled by surface rupture effects, comprising an effective rupture elongation along-dip due to a mirror effect and systematic changes of the shape factor relating slip to stress drop. Based on this physical insight, we propose a simplified formula to account for these effects in M 0- A scaling relations for strike-slip earthquakes.

  11. Criterion Noise in Ratings-Based Recognition: Evidence from the Effects of Response Scale Length on Recognition Accuracy

    Science.gov (United States)

    Benjamin, Aaron S.; Tullis, Jonathan G.; Lee, Ji Hae

    2013-01-01

    Rating scales are a standard measurement tool in psychological research. However, research has suggested that the cognitive burden involved in maintaining the criteria used to parcel subjective evidence into ratings introduces "decision noise" and affects estimates of performance in the underlying task. There has been debate over whether…

  12. Testing general relativity at cosmological scales: Implementation and parameter correlations

    International Nuclear Information System (INIS)

    Dossett, Jason N.; Ishak, Mustapha; Moldenhauer, Jacob

    2011-01-01

    The testing of general relativity at cosmological scales has become a possible and timely endeavor that is not only motivated by the pressing question of cosmic acceleration but also by the proposals of some extensions to general relativity that would manifest themselves at large scales of distance. We analyze here correlations between modified gravity growth parameters and some core cosmological parameters using the latest cosmological data sets including the refined Cosmic Evolution Survey 3D weak lensing. We provide the parametrized modified growth equations and their evolution. We implement known functional and binning approaches, and propose a new hybrid approach to evolve the modified gravity parameters in redshift (time) and scale. The hybrid parametrization combines a binned redshift dependence and a smooth evolution in scale avoiding a jump in the matter power spectrum. The formalism developed to test the consistency of current and future data with general relativity is implemented in a package that we make publicly available and call ISiTGR (Integrated Software in Testing General Relativity), an integrated set of modified modules for the publicly available packages CosmoMC and CAMB, including a modified version of the integrated Sachs-Wolfe-galaxy cross correlation module of Ho et al. and a new weak-lensing likelihood module for the refined Hubble Space Telescope Cosmic Evolution Survey weak gravitational lensing tomography data. We obtain parameter constraints and correlation coefficients finding that modified gravity parameters are significantly correlated with σ 8 and mildly correlated with Ω m , for all evolution methods. The degeneracies between σ 8 and modified gravity parameters are found to be substantial for the functional form and also for some specific bins in the hybrid and binned methods indicating that these degeneracies will need to be taken into consideration when using future high precision data.

  13. Scaling Relations of Starburst-driven Galactic Winds

    International Nuclear Information System (INIS)

    Tanner, Ryan; Cecil, Gerald; Heitsch, Fabian

    2017-01-01

    Using synthetic absorption lines generated from 3D hydrodynamical simulations, we explore how the velocity of a starburst-driven galactic wind correlates with the star formation rate (SFR) and SFR density. We find strong correlations for neutral and low ionized gas, but no correlation for highly ionized gas. The correlations for neutral and low ionized gas only hold for SFRs below a critical limit set by the mass loading of the starburst, above which point the scaling relations flatten abruptly. Below this point the scaling relations depend on the temperature regime being probed by the absorption line, not on the mass loading. The exact scaling relation depends on whether the maximum or mean velocity of the absorption line is used. We find that the outflow velocity of neutral gas can be up to five times lower than the average velocity of ionized gas, with the velocity difference increasing for higher ionization states. Furthermore, the velocity difference depends on both the SFR and mass loading of the starburst. Thus, absorption lines of neutral or low ionized gas cannot easily be used as a proxy for the outflow velocity of the hot gas.

  14. Scaling Relations of Starburst-driven Galactic Winds

    Energy Technology Data Exchange (ETDEWEB)

    Tanner, Ryan [Department of Chemistry and Physics, Augusta University, Augusta, GA 30912 (United States); Cecil, Gerald; Heitsch, Fabian, E-mail: rytanner@augusta.edu [Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3255 (United States)

    2017-07-10

    Using synthetic absorption lines generated from 3D hydrodynamical simulations, we explore how the velocity of a starburst-driven galactic wind correlates with the star formation rate (SFR) and SFR density. We find strong correlations for neutral and low ionized gas, but no correlation for highly ionized gas. The correlations for neutral and low ionized gas only hold for SFRs below a critical limit set by the mass loading of the starburst, above which point the scaling relations flatten abruptly. Below this point the scaling relations depend on the temperature regime being probed by the absorption line, not on the mass loading. The exact scaling relation depends on whether the maximum or mean velocity of the absorption line is used. We find that the outflow velocity of neutral gas can be up to five times lower than the average velocity of ionized gas, with the velocity difference increasing for higher ionization states. Furthermore, the velocity difference depends on both the SFR and mass loading of the starburst. Thus, absorption lines of neutral or low ionized gas cannot easily be used as a proxy for the outflow velocity of the hot gas.

  15. Extracorporeal shock-wave therapy effectively reduces calcaneal spur length and spur-related pain in overweight and obese patients.

    Science.gov (United States)

    Hayta, Emrullah; Salk, Ismail; Gumus, Cesur; Tuncay, Mehmet Siddik; Cetin, Ali

    2016-05-20

    We aimed to evaluate the effects of extra corporeal shock-wave therapy (ESWT) on the calcaneal spur length and pain severity in overweight and obese patients with symptomatic calcaneal spur. In eighty patients with symptomatic calcaneal spur, ESWT was administered on days 0 and 7, and visual analog scale (VAS) scores and calcaneal spur lengths (CSLs) before and 3 months later after treatment were recorded. A lateral heel radiograph was used for computer-aided linear measurements of CSL. Of 80 patients, 59 (73.7%) were female and 21 were male (26.3%); age was 45.9 ± 8.3 years; BMI was 31.6 ± 4.4 kg/m2; and symptom duration was 2.3 ± 2.4 years. The CSL and VAS score after treatment were significantly lower than those before treatment (CSL before vs. after: 5.7 ± 1.0 vs. 4.4 ± 0.9, p = 0.001; VAS score before vs. after: 8.3 ± 1.4 vs. 4.6 ± 2.2; p = 0.03). The CSLs before and after treatment had a significant strong correlation (r = 0.832, p = 0.001). The VAS scores before and after treatment presented a significant mild correlation (r = 0.242, p = 0.03). In overweight and obese patients with symptomatic calcaneal spur, ESWT reduces the CSL and pain severity during a follow-up of three-month duration.

  16. Large scale obscuration and related climate effects open literature bibliography

    International Nuclear Information System (INIS)

    Russell, N.A.; Geitgey, J.; Behl, Y.K.; Zak, B.D.

    1994-05-01

    Large scale obscuration and related climate effects of nuclear detonations first became a matter of concern in connection with the so-called ''Nuclear Winter Controversy'' in the early 1980's. Since then, the world has changed. Nevertheless, concern remains about the atmospheric effects of nuclear detonations, but the source of concern has shifted. Now it focuses less on global, and more on regional effects and their resulting impacts on the performance of electro-optical and other defense-related systems. This bibliography reflects the modified interest

  17. Large scale obscuration and related climate effects open literature bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Russell, N.A.; Geitgey, J.; Behl, Y.K.; Zak, B.D.

    1994-05-01

    Large scale obscuration and related climate effects of nuclear detonations first became a matter of concern in connection with the so-called ``Nuclear Winter Controversy`` in the early 1980`s. Since then, the world has changed. Nevertheless, concern remains about the atmospheric effects of nuclear detonations, but the source of concern has shifted. Now it focuses less on global, and more on regional effects and their resulting impacts on the performance of electro-optical and other defense-related systems. This bibliography reflects the modified interest.

  18. Evidence-Based Thresholds for the Volume and Length of Stay Relationship in Total Hip Arthroplasty: Outcomes and Economies of Scale.

    Science.gov (United States)

    Ramkumar, Prem N; Navarro, Sergio M; Frankel, William C; Haeberle, Heather S; Delanois, Ronald E; Mont, Michael A

    2018-02-05

    Several studies have indicated that high-volume surgeons and hospitals deliver higher value care. However, no evidence-based volume thresholds currently exist in total hip arthroplasty (THA). The primary objective of this study was to establish meaningful thresholds taking patient outcomes into consideration for surgeons and hospitals performing THA. A secondary objective was to examine the market share of THAs for each surgeon and hospital strata. Using 136,501 patients undergoing hip arthroplasty, we used stratum-specific likelihood ratio (SSLR) analysis of a receiver-operating characteristic curve to generate volume thresholds predictive of increased length of stay (LOS) for surgeons and hospitals. Additionally, we examined the relative proportion of annual THA cases performed by each surgeon and hospital strata established. SSLR analysis of LOS by annual surgeon THA volume produced 3 strata: 0-69 (low), 70-121 (medium), and 121 or more (high). Analysis by annual hospital THA volume produced strata at: 0-120 (low), 121-357 (medium), and 358 or more (high). LOS decreased significantly (P economies of scale in THA by demonstrating a direct relationship between volume and value for THA through risk-based volume stratification of surgeons and hospitals using SSLR analysis of receiver-operating characteristic curves to identify low-, medium-, and high-volume surgeons and hospitals. While the majority of primary THAs are performed at high-volume centers, low-volume surgeons are performing the majority of these cases, which may offer room for improvement in delivering value-based care. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. Quasi-Continuum Reduction of Field Theories: A Route to Seamlessly Bridge Quantum and Atomistic Length-Scales with Continuum

    Science.gov (United States)

    2016-04-01

    this form contains classified information, stamp classification level on the top and bottom of this page. 17. LIMITATION OF ABSTRACT. This block... techniques have been developed that enable large-scale real-space electronic structure calculations using Kohn-Sham density functional theory. In...particular, the various components of the developed techniques include (i) real-space formulation of Kohn-Sham density-functional theory (DFT) for both

  20. Current increment of tunnel field-effect transistor using InGaAs nanowire/Si heterojunction by scaling of channel length

    Science.gov (United States)

    Tomioka, Katsuhiro; Fukui, Takashi

    2014-02-01

    We report on a fabrication of tunnel field-effect transistors using InGaAs nanowire/Si heterojunctions and the characterization of scaling of channel lengths. The devices consisted of single InGaAs nanowires with a diameter of 30 nm grown on p-type Si(111) substrates. The switch demonstrated steep subthreshold-slope (30 mV/decade) at drain-source voltage (VDS) of 0.10 V. Also, pinch-off behavior appeared at moderately low VDS, below 0.10 V. Reducing the channel length of the transistors attained a steep subthreshold slope (<60 mV/decade) and enhanced the drain current, which was 100 higher than that of the longer channels.

  1. Global identification of the full-length transcripts and alternative splicing related to phenolic acid biosynthetic genes in Salvia miltiorrhiza

    Directory of Open Access Journals (Sweden)

    Zhichao eXu

    2016-02-01

    Full Text Available Salvianolic acids are among the main bioactive components in Salvia miltiorrhiza, and their biosynthesis has attracted widespread interest. However, previous studies on the biosynthesis of phenolic acids using next-generation sequencing platforms are limited with regard to the assembly of full-length transcripts. Based on hybrid-seq (next-generation and single molecular real-time sequencing of the S. miltiorrhiza root transcriptome, we experimentally identified 15 full-length transcripts and 4 alternative splicing events of enzyme-coding genes involved in the biosynthesis of rosmarinic acid. Moreover, we herein demonstrate that lithospermic acid B accumulates in the phloem and xylem of roots, in agreement with the expression patterns of the identified key genes related to rosmarinic acid biosynthesis. According to co-expression patterns, we predicted that 6 candidate cytochrome P450s and 5 candidate laccases participate in the salvianolic acid pathway. Our results provide a valuable resource for further investigation into the synthetic biology of phenolic acids in S. miltiorrhiza.

  2. Hyperopic refractive error and shorter axial length are associated with age-related macular degeneration: the Singapore Malay Eye Study.

    Science.gov (United States)

    Lavanya, Raghavan; Kawasaki, Ryo; Tay, Wan Ting; Cheung, Gemmy C M; Mitchell, Paul; Saw, Seang-Mei; Aung, Tin; Wong, Tien Y

    2010-12-01

    To describe the association between refractive errors, ocular biometry, and age-related macular degeneration (AMD) in an Asian Malay population in Singapore. A population-based study of 3280 Malay individuals aged 40 to 80 years was conducted in Singapore. Early- and late-AMD signs were graded from retinal photographs according to the Wisconsin grading system. Autorefraction, followed by subjective refraction, was performed to obtain spherical equivalent refraction (SER) in diopters, with emmetropia defined as SER -0.5 to +0.5 D, hyperopia as > +0.5 D, and myopia as education, height, and systolic blood pressure. Each diopter increase in hyperopic refraction and each millimeter decrease in axial length was associated with an 8% (OR, 1.08; CI, 1.01-1.16; P = 0.03) and 29% (OR, 1.29; CI, 1.06-1.57; P = 0.01) increased risk of early AMD, respectively. No significant association was noted of refractive error and ocular biometry with late AMD. Hyperopic refractive error and shorter axial length are associated with early AMD in Asian eyes.

  3. Fructans of chicory: intestinal transport and fermentation of different chain lengths and relation to fructose and sorbitol malabsorption.

    Science.gov (United States)

    Rumessen, J J; Gudmand-Høyer, E

    1998-08-01

    Fructans (fructooligosaccharides and inulin) are of increasing interest to clinical nutritionists as functional food additives. The chemically closely related food carbohydrates fructose and sorbitol are implicated in functional bowel disease. Intestinal handling of these carbohydrates is incompletely understood. Intestinal absorption, transit, and fermentation (breath hydrogen and methane, venous acetate, blood glucose, and urine fructans) after ingestion of 10-30 g short- and long-chain fructans from chicory were studied by single-blind, crossover randomization in 10 healthy adults. Responses were compared with responses after ingestion of lactulose, fructose, and sorbitol. Breath hydrogen and venous acetate production increased in proportion to increasing fructan dose and were similar to responses to lactulose. The transit times of long-chain fructans were longer than those of short-chain fructans (75 compared with 30 min, Pmalabsorption than were breath-hydrogen curves (Pmalabsorption of 50 g fructose, resulting in significantly more symptoms than 20 g fructose (Pmalabsorption or abdominal distress. Abdominal symptoms after fructans increased with increasing dose and decreasing chain length. The overall gastrointestinal effects of short-chain fructans seem similar to those of lactulose. Fructans with different chain lengths may have different physiologic properties and further studies of fructans in disease states are warranted.

  4. Scaling relations in the diffusive infiltration in fractals.

    Science.gov (United States)

    Aarão Reis, F D A

    2016-11-01

    In a recent work on fluid infiltration in a Hele-Shaw cell with the pore-block geometry of Sierpinski carpets (SCs), the area filled by the invading fluid was shown to scale as F∼t^{n}, with nfractals, but the exponent n is very different from the anomalous exponent ν=1/D_{W} of single-particle diffusion in the same fractals (D_{W} is the random-walk dimension). Here we use a scaling approach to show that those exponents are related as n=ν(D_{F}-D_{B}), where D_{F} and D_{B} are the fractal dimensions of the bulk and the border from which diffusing particles come, respectively. This relation is supported by accurate numerical estimates in two SCs and in two generalized Menger sponges (MSs), in which we performed simulations of single-particle random walks (RWs) with a rigid impermeable border and of a diffusive infiltration model in which that border is permanently filled with diffusing particles. This study includes one MS whose external border is also fractal. The exponent relation is also consistent with the recent simulational and experimental results on fluid infiltration in SCs, and explains the approximate quadratic dependence of n on D_{F} in these fractals. We also show that the mean-square displacement of single-particle RWs has log-periodic oscillations, whose periods are similar for fractals with the same scaling factor in the generator (even with different embedding dimensions), which is consistent with the discrete scale invariance scenario. The roughness of a diffusion front defined in the infiltration problem also shows this type of oscillation, which is enhanced in fractals with narrow channels between large lacunas.

  5. Length-displacement scaling of thrust faults on the Moon and the formation of uphill-facing scarps

    Science.gov (United States)

    Roggon, Lars; Hetzel, Ralf; Hiesinger, Harald; Clark, Jaclyn D.; Hampel, Andrea; van der Bogert, Carolyn H.

    2017-08-01

    Fault populations on terrestrial planets exhibit a linear relationship between their length, L, and the maximum displacement, D, which implies a constant D/L ratio during fault growth. Although it is known that D/L ratios of faults are typically a few percent on Earth and 0.2-0.8% on Mars and Mercury, the D/L ratios of lunar faults are not well characterized. Quantifying the D/L ratios of faults on the Moon is, however, crucial for a better understanding of lunar tectonics, including for studies of the amount of global lunar contraction. Here, we use high-resolution digital terrain models to perform a topographic analysis of four lunar thrust faults - Simpelius-1, Morozov (S1), Fowler, and Racah X-1 - that range in length from 1.3 km to 15.4 km. First, we determine the along-strike variation of the vertical displacement from ≥ 20 topographic profiles across each fault. For measuring the vertical displacements, we use a method that is commonly applied to fault scarps on Earth and that does not require detrending of the profiles. The resulting profiles show that the displacement changes gradually along these faults' strike, with maximum vertical displacements ranging from 17 ± 2 m for Simpelius-1 to 192 ± 30 m for Racah X-1. Assuming a fault dip of 30° yields maximum total displacements (D) that are twice as large as the vertical displacements. The linear relationship between D and L supports the inference that lunar faults gradually accumulate displacement as they propagate laterally. For the faults we investigated, the D/L ratio is ∼2.3%, an order of magnitude higher than theoretical predictions for the Moon, but a value similar for faults on Earth. We also employ finite-element modeling and a Mohr circle stress analysis to investigate why many lunar thrust faults, including three of those studied here, form uphill-facing scarps. Our analysis shows that fault slip is preferentially initiated on planes that dip in the same direction as the topography, because

  6. Morphological quantification of hierarchical geomaterials by X-ray nano-CT bridges the gap from nano to micro length scales

    KAUST Repository

    Brisard, S.

    2012-01-30

    Morphological quantification of the complex structure of hierarchical geomaterials is of great relevance for Earth science and environmental engineering, among others. To date, methods that quantify the 3D morphology on length scales ranging from a few tens of nanometers to several hun-dred nanometers have had limited success. We demonstrate, for the first time, that it is possible to go beyond visualization and to extract quantitative morphological information from X-ray images in the aforementioned length scales. As examples, two different hierarchical geomaterials exhibiting complex porous structures ranging from nanometer to macroscopic scale are studied: a flocculated clay water suspension and two hydrated cement pastes. We show that from a single projection image it is possible to perform a direct computation of the ultra-small angle-scattering spectra. The predictions matched very well the experimental data obtained by the best ultra-small angle-scattering experimental setups as observed for the cement paste. In this context, we demonstrate that the structure of flocculated clay suspension exhibit two well-distinct regimes of aggregation, a dense mass fractal aggregation at short distance and a more open structure at large distance, which can be generated by a 3D reaction limited cluster-cluster aggregation process. For the first time, a high-resolution 3D image of fibrillar cement paste cluster was obtained from limited angle nanotomography.

  7. Search for Screened Interactions Associated with Dark Energy below the 100 μm Length Scale.

    Science.gov (United States)

    Rider, Alexander D; Moore, David C; Blakemore, Charles P; Louis, Maxime; Lu, Marie; Gratta, Giorgio

    2016-09-02

    We present the results of a search for unknown interactions that couple to mass between an optically levitated microsphere and a gold-coated silicon cantilever. The scale and geometry of the apparatus enable a search for new forces that appear at distances below 100  μm and which would have evaded previous searches due to screening mechanisms. The data are consistent with electrostatic backgrounds and place upper limits on the strength of new interactions at 5.6×10^{4} in the region of parameter space where the self-coupling Λ≳5  meV and the microspheres are not fully screened.

  8. Size variation and collapse of emphysema holes at inspiration and expiration CT scan: evaluation with modified length scale method and image co-registration

    Directory of Open Access Journals (Sweden)

    Oh SY

    2017-07-01

    −0.40, and with diffusing capacity of the lungs for carbon monoxide (cDLco, respectively. The fraction of emphysema that shifted to the smaller subgroup showed a significant correlation with FEV1, cDLco, forced expiratory flow at 25%–75% of forced vital capacity, and residual volume (RV/total lung capacity (r=0.56, 0.73, 0.40, and −0.58. A detailed assessment of the size variation and collapse of emphysema holes may be useful for understanding the dynamic collapse of emphysema and its functional relation. Keywords: chronic obstructive pulmonary disease, computed tomography, emphysema size, length scale analysis, quantitative imaging, emphysema size change

  9. Multi-length-scale Material Model for SiC/SiC Ceramic-Matrix Composites (CMCs): Inclusion of In-Service Environmental Effects

    Science.gov (United States)

    Grujicic, M.; Galgalikar, R.; Snipes, J. S.; Ramaswami, S.

    2016-01-01

    In our recent work, a multi-length-scale room-temperature material model for SiC/SiC ceramic-matrix composites (CMCs) was derived and parameterized. The model was subsequently linked with a finite-element solver so that it could be used in a general room-temperature, structural/damage analysis of gas-turbine engine CMC components. Due to its multi-length-scale character, the material model enabled inclusion of the effects of fiber/tow (e.g., the volume fraction, size, and properties of the fibers; fiber-coating material/thickness; decohesion properties of the coating/matrix interfaces; etc.) and ply/lamina (e.g., the 0°/90° cross-ply versus plain-weave architectures, the extent of tow crimping in the case of the plain-weave plies, cohesive properties of the inter-ply boundaries, etc.) length-scale microstructural/architectural parameters on the mechanical response of the CMCs. One of the major limitations of the model is that it applies to the CMCs in their as-fabricated conditions (i.e., the effect of prolonged in-service environmental exposure and the associated material aging-degradation is not accounted for). In the present work, the model is upgraded to include such in-service environmental-exposure effects. To demonstrate the utility of the upgraded material model, it is used within a finite-element structural/failure analysis involving impact of a toboggan-shaped turbine shroud segment by a foreign object. The results obtained clearly revealed the effects that different aspects of the in-service environmental exposure have on the material degradation and the extent of damage suffered by the impacted CMC toboggan-shaped shroud segment.

  10. Correlation of Leukocyte Telomere Length Measurement Methods in Patients with Dyskeratosis Congenita and in Their Unaffected Relatives.

    Science.gov (United States)

    Khincha, Payal P; Dagnall, Casey L; Hicks, Belynda; Jones, Kristine; Aviv, Abraham; Kimura, Masayuki; Katki, Hormuzd; Aubert, Geraldine; Giri, Neelam; Alter, Blanche P; Savage, Sharon A; Gadalla, Shahinaz M

    2017-08-13

    Several methods have been employed to measure telomere length (TL) in human studies. It has been difficult to directly compare the results from these studies because of differences in the laboratory techniques and output parameters. We compared TL measurements (TLMs) by the three most commonly used methods, quantitative polymerase chain reaction (qPCR), flow cytometry with fluorescence in situ hybridization (flow FISH) and Southern blot, in a cohort of patients with the telomere biology disorder dyskeratosis congenita (DC) and in their unaffected relatives (controls). We observed a strong correlation between the Southern blot average TL and the flow FISH total lymphocyte TL in both the DC patients and their unaffected relatives ( R ² of 0.68 and 0.73, respectively). The correlation between the qPCR average TL and that of the Southern blot method was modest ( R ² of 0.54 in DC patients and of 0.43 in unaffected relatives). Similar results were noted when comparing the qPCR average TL and the flow FISH total lymphocyte TL ( R ² of 0.49 in DC patients and of 0.42 in unaffected relatives). In conclusion, the strengths of the correlations between the three widely used TL assays (qPCR, flow FISH, and Southern blot) were significantly different. Careful consideration is warranted when selecting the method of TL measurement for research and for clinical studies.

  11. Correlation of Leukocyte Telomere Length Measurement Methods in Patients with Dyskeratosis Congenita and in Their Unaffected Relatives

    Science.gov (United States)

    Khincha, Payal P.; Hicks, Belynda; Jones, Kristine; Aviv, Abraham; Kimura, Masayuki; Katki, Hormuzd; Aubert, Geraldine; Giri, Neelam; Alter, Blanche P.; Savage, Sharon A.; Gadalla, Shahinaz M.

    2017-01-01

    Several methods have been employed to measure telomere length (TL) in human studies. It has been difficult to directly compare the results from these studies because of differences in the laboratory techniques and output parameters. We compared TL measurements (TLMs) by the three most commonly used methods, quantitative polymerase chain reaction (qPCR), flow cytometry with fluorescence in situ hybridization (flow FISH) and Southern blot, in a cohort of patients with the telomere biology disorder dyskeratosis congenita (DC) and in their unaffected relatives (controls). We observed a strong correlation between the Southern blot average TL and the flow FISH total lymphocyte TL in both the DC patients and their unaffected relatives (R2 of 0.68 and 0.73, respectively). The correlation between the qPCR average TL and that of the Southern blot method was modest (R2 of 0.54 in DC patients and of 0.43 in unaffected relatives). Similar results were noted when comparing the qPCR average TL and the flow FISH total lymphocyte TL (R2 of 0.49 in DC patients and of 0.42 in unaffected relatives). In conclusion, the strengths of the correlations between the three widely used TL assays (qPCR, flow FISH, and Southern blot) were significantly different. Careful consideration is warranted when selecting the method of TL measurement for research and for clinical studies. PMID:28805708

  12. A long life in good health: subjective expectations regarding length and future health-related quality of life.

    Science.gov (United States)

    Rappange, David R; Brouwer, Werner B F; van Exel, Job

    2016-06-01

    Subjective life expectancy is considered relevant in predicting mortality and future demand for health services as well as for explaining peoples' decisions in several life domains, such as the perceived impact of health behaviour changes on future health outcomes. Such expectations and in particular subjective expectations regarding future health-related quality of life remain understudied. The purpose of this study was to investigate individuals' subjective quality adjusted life years (QALYs) expectation from age 65 onwards in a representative sample of the Dutch generic public. A web-based questionnaire was administered to a sample of the adult population from the Netherlands. Information on subjective expectations regarding length and future health-related quality of life were combined into one single measure of subjective expected QALYs from age 65 onwards. This subjective QALY expectation was related to background, health and lifestyle variables. The implications of using different methods to construct our main outcome measure were addressed. Mean subjective expected QALYs from age 65 onwards was 11 QALYs (range -9 to 40 QALYs). Individuals with unhealthier lifestyles, chronic diseases, severe disorders or lower age of death of next of kin reported lower QALY expectations. Indicators were varyingly associated with either subjective life expectancy or future health-related quality of life, or both. Extending the concept of subjective life expectancy by correcting for expected quality of life appears to generate important additional information contributing to our understanding of people's perceptions regarding ageing and lifestyle choices.

  13. Length-weight relation and condition factor of @iPenaeus indicus@@ and @iMetapenaeus dobsoni@@ in the Cochin Backwater

    Digital Repository Service at National Institute of Oceanography (India)

    Devi, C.B.L.; Nair, K.K.C.; Balasubramanian, T.; Gopalakrishnan, T.C.; Aravindakshan, P.N.; Kutty, M.K.

    Length-weight relation and condition factor of @iPenaeus indicus@@ and @iMetapenaeus dobsoni@@ were estimated using samples from Cochin backwater. Statistical tests support the view that the length-weight exponent of these species may be species...

  14. Intensity limits for propagation of 0.527 μm laser beams through large-scale-length plasmas for inertial confinement fusion

    International Nuclear Information System (INIS)

    Niemann, C.; Divol, L.; Froula, D.H.; Gregori, G.; Jones, O.; Kirkwood, R.K.; MacKinnon, A.J.; Meezan, N.B.; Moody, J.D.; Sorce, C.; Suter, L.J.; Glenzer, S.H.; Bahr, R.; Seka, W.

    2005-01-01

    We have established the intensity limits for propagation of a frequency-doubled (2ω, 527 nm) high intensity interaction beam through an underdense large-scale-length plasma. We observe good beam transmission at laser intensities at or below 2x10 14 W/cm 2 and a strong reduction at intensities up to 10 15 W/cm 2 due to the onset of parametric scattering instabilities. We show that temporal beam smoothing by spectral dispersion allows a factor of 2 higher intensities while keeping the beam spray constant, which establishes frequency-doubled light as an option for ignition and burn in inertial confinement fusion experiments

  15. Relating rainfall characteristics to cloud top temperatures at different scales

    Science.gov (United States)

    Klein, Cornelia; Belušić, Danijel; Taylor, Christopher

    2017-04-01

    Extreme rainfall from mesoscale convective systems (MCS) poses a threat to lives and livelihoods of the West African population through increasingly frequent devastating flooding and loss of crops. However, despite the significant impact of such extreme events, the dominant processes favouring their occurrence are still under debate. In the data-sparse West African region, rainfall radar data from the Tropical Rainfall Measuring Mission (TRMM) gives invaluable information on the distribution and frequency of extreme rainfall. The TRMM 2A25 product provides a 15-year dataset of snapshots of surface rainfall from 2-4 overpasses per day. Whilst this sampling captures the overall rainfall characteristics, it is neither long nor frequent enough to diagnose changes in MCS properties, which may be linked to the trend towards rainfall intensification in the region. On the other hand, Meteosat geostationary satellites provide long-term sub-hourly records of cloud top temperatures, raising the possibility of combining these with the high-quality rainfall data from TRMM. In this study, we relate TRMM 2A25 rainfall to Meteosat Second Generation (MSG) cloud top temperatures, which are available from 2004 at 15 minutes intervals, to get a more detailed picture of the structure of intense rainfall within the life cycle of MCS. We find TRMM rainfall intensities within an MCS to be strongly coupled with MSG cloud top temperatures: the probability for extreme rainfall increases from power spectra at scales between 15 and 200km. From these, cloud sub-structures are identified as circular areas of respective scale with local power maxima in their centre. These areas are then mapped onto coinciding TRMM rainfall, allowing us to assign rainfall fields to sub-cloud features of different scales. We find a higher probability for extreme rainfall for cloud features above a scale of 30km, with features 100km contributing most to the number of extreme rainfall pixels. Over the average diurnal

  16. Rapid differentiation of closely related isolates of two plant viruses by polymerase chain reaction and restriction fragment length polymorphism analysis.

    Science.gov (United States)

    Barbara, D J; Morton, A; Spence, N J; Miller, A

    1995-09-01

    Immunocapture reverse transcriptase-polymerase chain reaction (RT-PCR) followed by restriction fragment length polymorphism (RFLP) analysis of the product has been shown to be an effective procedure for discriminating serologically indistinguishable isolates of two plant viruses, raspberry bushy dwarf (RBDV) and zucchini yellow mosaic (ZYMV). For both viruses, only limited sequence information was available at the time of primer design, but most of the isolates which were tested could be amplified (the one exception being a serologically quite distinct isolate of ZYMV). Restriction endonucleases revealing diagnostic RFLPs were readily identified. Each of two isolates of ZYMV could be detected in the presence of the other and the relative proportions approximately quantified by visual estimation of the relative intensity of the appropriate bands. A range of isolates of different RBDV pathotypes were compared; isolates were grouped in ways that accorded with their known history. Computer analysis of the published sequence from which the primers had been derived showed the sequenced isolate to be identical with an isolate imported from the USSR. The PCR/RFLP procedure is rapid (it can be completed in less than 2 days), effective and will probably be generally applicable to distinguishing closely related virus isolates, even where little sequence information is available.

  17. Functional Independent Scaling Relation for ORR/OER Catalysts

    DEFF Research Database (Denmark)

    Christensen, Rune; Hansen, Heine Anton; Dickens, Colin F.

    2016-01-01

    A widely used adsorption energy scaling relation between OH* and OOH* intermediates in the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), has previously been determined using density functional theory and shown to dictate a minimum thermodynamic overpotential for both...... reactions. Here, we show that the oxygen-oxygen bond in the OOH* intermediate is, however, not well described with the previously used class of exchange-correlation functionals. By quantifying and correcting the systematic error, an improved description of gaseous peroxide species versus experimental data...

  18. Free energy of cluster formation and a new scaling relation for the nucleation rate

    International Nuclear Information System (INIS)

    Tanaka, Kyoko K.; Tanaka, Hidekazu; Diemand, Jürg; Angélil, Raymond

    2014-01-01

    Recent very large molecular dynamics simulations of homogeneous nucleation with (1 − 8) × 10 9 Lennard-Jones atoms [J. Diemand, R. Angélil, K. K. Tanaka, and H. Tanaka, J. Chem. Phys. 139, 074309 (2013)] allow us to accurately determine the formation free energy of clusters over a wide range of cluster sizes. This is now possible because such large simulations allow for very precise measurements of the cluster size distribution in the steady state nucleation regime. The peaks of the free energy curves give critical cluster sizes, which agree well with independent estimates based on the nucleation theorem. Using these results, we derive an analytical formula and a new scaling relation for nucleation rates: ln J ′ /η is scaled by ln S/η, where the supersaturation ratio is S, η is the dimensionless surface energy, and J ′ is a dimensionless nucleation rate. This relation can be derived using the free energy of cluster formation at equilibrium which corresponds to the surface energy required to form the vapor-liquid interface. At low temperatures (below the triple point), we find that the surface energy divided by that of the classical nucleation theory does not depend on temperature, which leads to the scaling relation and implies a constant, positive Tolman length equal to half of the mean inter-particle separation in the liquid phase

  19. The Cancer Loneliness Scale and Cancer-related Negative Social Expectations Scale: development and validation.

    Science.gov (United States)

    Adams, Rebecca N; Mosher, Catherine E; Rand, Kevin L; Hirsh, Adam T; Monahan, Patrick O; Abonour, Rafat; Kroenke, Kurt

    2017-07-01

    Loneliness is a known risk factor for poor mental and physical health outcomes and quality of life in the general population, and preliminary research suggests that loneliness is linked to poorer health outcomes in cancer patients as well. Various aspects of the cancer experience contribute to patients feeling alone and misunderstood. Furthermore, loneliness theory suggests that negative social expectations, which may specifically relate to the cancer experience, precipitate and sustain loneliness. Cancer-specific tools are needed to assess key constructs of this theory. In the current study, we developed and tested measures of (1) loneliness attributed to cancer (i.e., cancer-related loneliness) and (2) negative social expectations related to cancer. First, we developed the items for the measures based on theory, prior research, and expert feedback. Next, we assessed the measures' psychometric properties (i.e., internal consistency and construct validity) in a diverse sample of cancer patients. The final products included a 7-item unidimensional Cancer Loneliness Scale and a 5-item unidimensional Cancer-related Negative Social Expectations Scale. Evidence of excellent reliability and validity was found for both measures. The resulting measures have both clinical and research utility.

  20. Phase Behavior of Blends of Linear and Branched Polyethylenes on Micron-Length Scales via Ultra-Small-Angle Neutron Scattering (USANS)

    International Nuclear Information System (INIS)

    Agamalian, M.M.; Alamo, R.G.; Londono, J.D.; Mandelkern, L.; Wignall, G.D.

    1999-01-01

    SANS experiments on blends of linear, high density (HD) and long chain branched, low density (LD) polyethylenes indicate that these systems form a one-phase mixture in the melt. However, the maximum spatial resolution of pinhole cameras is approximately equal to 10 3 and it has therefore been suggested that data might also be interpreted as arising from a bi-phasic melt with large a particle size ( 1 m), because most of the scattering from the different phases would not be resolved. We have addressed this hypothesis by means of USANS experiments, which confirm that HDPEILDPE blends are homogenous in the melt on length scales up to 20 m. We have also studied blends of HDPE and short-chain branched linear low density polyethylenes (LLDPEs), which phase separate when the branch content is sufficiently high. LLDPEs prepared with Ziegler-Natta catalysts exhibit a wide distribution of compositions, and may therefore be thought of as a blend of different species. When the composition distribution is broad enough, a fraction of highly branched chains may phase separate on m-length scales, and USANS has also been used to quantify this phenomenon

  1. Eye size and shape in newborn children and their relation to axial length and refraction at 3 years.

    Science.gov (United States)

    Lim, Laurence Shen; Chua, Sharon; Tan, Pei Ting; Cai, Shirong; Chong, Yap-Seng; Kwek, Kenneth; Gluckman, Peter D; Fortier, Marielle V; Ngo, Cheryl; Qiu, Anqi; Saw, Seang-Mei

    2015-07-01

    To determine if eye size and shape at birth are associated with eye size and refractive error 3 years later. A subset of 173 full-term newborn infants from the Growing Up in Singapore Towards healthy Outcomes (GUSTO) birth cohort underwent magnetic resonance imaging (MRI) to measure the dimensions of the internal eye. Eye shape was assessed by an oblateness index, calculated as 1 - (axial length/width) or 1 - (axial length/height). Cycloplegic autorefraction (Canon Autorefractor RK-F1) and optical biometry (IOLMaster) were performed 3 years later. Both eyes of 173 children were analysed. Eyes with longer axial length at birth had smaller increases in axial length at 3 years (p Eyes with larger baseline volumes and surface areas had smaller increases in axial length at 3 years (p Eyes which were more oblate at birth had greater increases in axial length at 3 years (p eyes had smaller increases in axial length at 3 years compared to oblate eyes (p eyes had smaller increases in axial length at 3 years compared to oblate eyes (p eye size and shape at birth and refraction, corneal curvature or myopia at 3 years. Eyes that are larger and have prolate or spherical shapes at birth exhibit smaller increases in axial length over the first 3 years of life. Eye size and shape at birth influence subsequent eye growth but not refractive error development. © 2015 The Authors Ophthalmic & Physiological Optics © 2015 The College of Optometrists.

  2. X-Ray Scaling Relations of Early-type Galaxies

    Science.gov (United States)

    Babyk, Iu. V.; McNamara, B. R.; Nulsen, P. E. J.; Hogan, M. T.; Vantyghem, A. N.; Russell, H. R.; Pulido, F. A.; Edge, A. C.

    2018-04-01

    X-ray luminosity, temperature, gas mass, total mass, and their scaling relations are derived for 94 early-type galaxies (ETGs) using archival Chandra X-ray Observatory observations. Consistent with earlier studies, the scaling relations, L X ∝ T 4.5±0.2, M ∝ T 2.4±0.2, and L X ∝ M 2.8±0.3, are significantly steeper than expected from self-similarity. This steepening indicates that their atmospheres are heated above the level expected from gravitational infall alone. Energetic feedback from nuclear black holes and supernova explosions are likely heating agents. The tight L X –T correlation for low-luminosity systems (i.e., below 1040 erg s‑1) are at variance with hydrodynamical simulations, which generally predict higher temperatures for low-luminosity galaxies. We also investigate the relationship between total mass and pressure, Y X = M g × T, finding M\\propto {Y}X0.45+/- 0.04. We explore the gas mass to total mass fraction in ETGs and find a range of 0.1%–1.0%. We find no correlation between the gas-to-total mass fraction with temperature or total mass. Higher stellar velocity dispersions and higher metallicities are found in hotter, brighter, and more massive atmospheres. X-ray core radii derived from β-model fitting are used to characterize the degree of core and cuspiness of hot atmospheres.

  3. Position and momentum uncertainties of the normal and inverted harmonic oscillators under the minimal length uncertainty relation

    International Nuclear Information System (INIS)

    Lewis, Zachary; Takeuchi, Tatsu

    2011-01-01

    We analyze the position and momentum uncertainties of the energy eigenstates of the harmonic oscillator in the context of a deformed quantum mechanics, namely, that in which the commutator between the position and momentum operators is given by [x-circumflex,p-circumflex]=i(ℎ/2π)(1+βp-circumflex 2 ). This deformed commutation relation leads to the minimal length uncertainty relation Δx≥((ℎ/2π)/2)(1/Δp+βΔp), which implies that Δx∼1/Δp at small Δp while Δx∼Δp at large Δp. We find that the uncertainties of the energy eigenstates of the normal harmonic oscillator (m>0), derived in L. N. Chang, D. Minic, N. Okamura, and T. Takeuchi, Phys. Rev. D 65, 125027 (2002), only populate the Δx∼1/Δp branch. The other branch, Δx∼Δp, is found to be populated by the energy eigenstates of the 'inverted' harmonic oscillator (m min =(ℎ/2π)√(β)>√(2)[(ℎ/2π) 2 /k|m|] 1/4 . Correspondence with the classical limit is also discussed.

  4. EXPERIMENTAL INVESTIGATION OF RELATIVE PERMEABILITY UPSCALING FROM THE MICRO-SCALE TO THE MACRO-SCALE

    Energy Technology Data Exchange (ETDEWEB)

    Laura J. Pyrak-Nolte; Nicholas J. Giordano; David D. Nolte

    2004-03-01

    The principal challenge of upscaling techniques for multi-phase fluid dynamics in porous media is to determine which properties on the micro-scale can be used to predict macroscopic flow and spatial distribution of phases at core- and field-scales. The most notable outcome of recent theories is the identification of interfacial areas per volume for multiple phases as a fundamental parameter that determines much of the multi-phase properties of the porous medium. A formal program of experimental research was begun to directly test upscaling theories in fluid flow through porous media by comparing measurements of relative permeability and capillary-saturation with measurements of interfacial area per volume. This project on the experimental investigation of relative permeability upscaling has produced a unique combination of three quite different technical approaches to the upscaling problem of obtaining pore-related microscopic properties and using them to predict macroscopic behavior. Several important ''firsts'' have been achieved during the course of the project. (1) Optical coherence imaging, a laser-based ranging and imaging technique, has produced the first images of grain and pore structure up to 1 mm beneath the surface of the sandstone and in a laboratory borehole. (2) Woods metal injection has connected for the first time microscopic pore-scale geometric measurements with macroscopic saturation in real sandstone cores. (3) The micro-model technique has produced the first invertible relationship between saturation and capillary pressure--showing that interfacial area per volume (IAV) provides the linking parameter. IAV is a key element in upscaling theories, so this experimental finding may represent the most important result of this project, with wide ramifications for predictions of fluid behavior in porous media.

  5. Studying Soft-matter and Biological Systems over a Wide Length-scale from Nanometer and Micrometer Sizes at the Small-angle Neutron Diffractometer KWS-2

    Science.gov (United States)

    Radulescu, Aurel; Szekely, Noemi Kinga; Appavou, Marie-Sousai; Pipich, Vitaliy; Kohnke, Thomas; Ossovyi, Vladimir; Staringer, Simon; Schneider, Gerald J.; Amann, Matthias; Zhang-Haagen, Bo; Brandl, Georg; Drochner, Matthias; Engels, Ralf; Hanslik, Romuald; Kemmerling, Günter

    2016-01-01

    The KWS-2 SANS diffractometer is dedicated to the investigation of soft matter and biophysical systems covering a wide length scale, from nm to µm. The instrument is optimized for the exploration of the wide momentum transfer Q range between 1x10-4 and 0.5 Å-1 by combining classical pinhole, focusing (with lenses), and time-of-flight (with chopper) methods, while simultaneously providing high-neutron intensities with an adjustable resolution. Because of its ability to adjust the intensity and the resolution within wide limits during the experiment, combined with the possibility to equip specific sample environments and ancillary devices, the KWS-2 shows a high versatility in addressing the broad range of structural and morphological studies in the field. Equilibrium structures can be studied in static measurements, while dynamic and kinetic processes can be investigated over time scales between minutes to tens of milliseconds with time-resolved approaches. Typical systems that are investigated with the KWS-2 cover the range from complex, hierarchical systems that exhibit multiple structural levels (e.g., gels, networks, or macro-aggregates) to small and poorly-scattering systems (e.g., single polymers or proteins in solution). The recent upgrade of the detection system, which enables the detection of count rates in the MHz range, opens new opportunities to study even very small biological morphologies in buffer solution with weak scattering signals close to the buffer scattering level at high Q. In this paper, we provide a protocol to investigate samples with characteristic size levels spanning a wide length scale and exhibiting ordering in the mesoscale structure using KWS-2. We present in detail how to use the multiple working modes that are offered by the instrument and the level of performance that is achieved. PMID:28060296

  6. A dual length scale method for plane-wave-based, simulation studies of chemical systems modeled using mixed ab initio/empirical force field descriptions

    Science.gov (United States)

    Yarne, Dawn A.; Tuckerman, Mark E.; Martyna, Glenn J.

    2001-08-01

    Mixed ab initio/empirical force-field simulation studies, calculations in which one part of the system is treated using a fully ab initio description and another part is treated using an empirical description, are becoming increasingly popular. Here, the ability of the commonly used, plane wave-based generalized gradient approximation to density functional theory is extended to model systems in which the electrons are assumed to be localized in a single small region of space, that is, itself, embedded within a large chemically inert bath. This is accomplished by introducing two length scales, so that the rapidly varying, short range, electron-electron and electron-atom interactions, arising from the region where the electrons are localized, can be treated using an appropriately large plane wave basis, while the corresponding, slowly varying, long range interactions of the electrons with the full system or bath, can be treated using a small basis. Briefly, a novel Cardinal B-spline based formalism is employed to derive a smooth, differentiable, and rapidly convergent (with respect to the small basis) expression for the total electronic energy, which explicitly contains the two length scales. The method allows reciprocal space based techniques designed to treat clusters, wires, surfaces and solids/liquids (open, and 1-D and 2-D periodic boundary conditions, respectively) to be utilized. Other plane wave-based "mixed" methods are restricted to clusters. The new methodology, which scales as N log N at fixed size of the chemically active region, has been implemented for parallel computing platforms and tested through applications to both model and realistic problems including an enzyme, human carbonic anhydrase II solvated in an explicit bath of water molecules.

  7. Ambiguous tests of general relativity on cosmological scales

    International Nuclear Information System (INIS)

    Zuntz, Joe; Baker, Tessa; Ferreira, Pedro G.; Skordis, Constantinos

    2012-01-01

    There are a number of approaches to testing General Relativity (GR) on linear scales using parameterized frameworks for modifying cosmological perturbation theory. It is sometimes assumed that the details of any given parameterization are unimportant if one uses it as a diagnostic for deviations from GR. In this brief report we argue that this is not necessarily so. First we show that adopting alternative combinations of modifications to the field equations significantly changes the constraints that one obtains. In addition, we show that using a parameterization with insufficient freedom significantly tightens the apparent theoretical constraints. Fundamentally we argue that it is almost never appropriate to consider modifications to the perturbed Einstein equations as being constraints on the effective gravitational constant, for example, in the same sense that solar system constraints are. The only consistent modifications are either those that grant near-total freedom, as in decomposition methods, or ones which map directly to a particular part of theory space

  8. Relation of Telemetry Use and Mortality Risk, Hospital Length of Stay, and Readmission Rates in Patients With Respiratory Illness.

    Science.gov (United States)

    Dawson, Nancy; Burton, M Caroline; Hull, Bryan; Beliles, Gregory; Pritchard, Ingrid; Trautman, Christopher; Ferry, Laura; Doyon, Amanda; Colby, Rebecca; Chuu, Andy; Kung, Shu Ting; Khang, Tran; Durocher, Donna; Buras, Matthew; Kosiorek, Heidi; Agrwal, Neera; Sen, Ayan; Goss, Darin; Geyer, Holly

    2017-10-15

    The 2004 American Heart Association expert opinion-based guidelines restrict telemetry use primarily to patients with current or high-risk cardiac conditions. Respiratory infections have emerged as a common source of hospitalization, and telemetry is frequently applied without indication in efforts to monitor patient decompensation. In this retrospective study, we aimed to determine whether telemetry impacts mortality risk, length of stay (LOS), or readmission rates in hospitalized patients with acute respiratory infection not meeting American Heart Association criteria. A total of 765 respiratory infection patient encounters with Diagnosis-Related Groups 193, 194, 195, 177, 178 and 179 admitted in 2013 to 2015 to 2 tertiary community-based medical centers (Mayo Clinic, Arizona, and Mayo Clinic, Florida) were evaluated, and outcomes between patients who underwent or did not undergo telemetry were compared. Overall, the median LOS was longer in patients who underwent telemetry (3.0 days vs 2.0 days, p Telemetry predicted LOS for both univariate (estimate 1.18, 95% confidence interval 1.06 to 1.32, p = 0.003) and multivariate (estimate 1.17, 95% confidence interval 1.06 to 1.30, p = 0.003) analyses after controlling for severity of illness but did not predict patient mortality. In conclusion, this study identified that patients with respiratory infection who underwent telemetry without clear indications may face increased LOS without reducing their readmission risk or improving the overall mortality. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Relating Silica Scaling in Reverse Osmosis to Membrane Surface Properties.

    Science.gov (United States)

    Tong, Tiezheng; Zhao, Song; Boo, Chanhee; Hashmi, Sara M; Elimelech, Menachem

    2017-04-18

    We investigated the relationship between membrane surface properties and silica scaling in reverse osmosis (RO). The effects of membrane hydrophilicity, free energy for heterogeneous nucleation, and surface charge on silica scaling were examined by comparing thin-film composite polyamide membranes grafted with a variety of polymers. Results show that the rate of silica scaling was independent of both membrane hydrophilicity and free energy for heterogeneous nucleation. In contrast, membrane surface charge demonstrated a strong correlation with the extent of silica scaling (R 2 > 0.95, p scaling, whereas a more negative membrane surface charge led to reduced scaling. This observation suggests that deposition of negatively charged silica species on the membrane surface plays a critical role in silica scale formation. Our findings provide fundamental insights into the mechanisms governing silica scaling in reverse osmosis and highlight the potential of membrane surface modification as a strategy to reduce silica scaling.

  10. Factors affecting hospital length of stay and hospital charges associated with road traffic-related injuries in Iran

    Science.gov (United States)

    2013-01-01

    Background Road traffic injuries (RTIs) are a substantial cause of mortality and disability globally. There is little published information regarding healthcare resource utilization following RTIs, especially in low and middle-income countries (LMICs). The aim of this study was to assess total hospital charges and length of stay (LOS) associated with RTIs in Iran and to explore the association with patients’ socio-demographic characteristics, insurance status and injury-related factors (e.g. type of road users and safety equipment). Method The study was based on the Iranian National Trauma Registry Database (INTRD), which includes data from 14 general hospitals in eight major cities in Iran, for the years 2000 to 2004. 8,356 patients with RTI admitted to the hospitals were included in the current study. The variables extracted for the analysis included total hospital charges and length of stay, age, gender, socio-economic and insurance status, injury characteristics, medical outcome and use of safety equipment among the patients. Univariable analysis using non-parametric methods and multivariable regression analysis were performed to identify the factors associated with total hospital charges and LOS. Results The mean hospital charges for the patients were 1,115,819 IRR (SD=1,831,647 IRR, US$128 ± US$210). The mean LOS for the patients was 6.8 (SD =8 days). Older age, being a bicycle rider, higher injury severity and longer LOS were associated with higher hospital charges. Longer LOS was associated with being male, having lower education level, having a medical insurance, being pedestrian or motorcyclist, being a blue-collar worker and having more severe injuries. The reported use of safety equipment was very low and did not have significant effect on the hospital charges and LOS. Conclusion The study demonstrated that the hospital charges and LOS associated with RTI varied by age, gender, socio-economic status, insurance status, injury characteristics and

  11. Overview of lower length scale model development for accident tolerant fuels regarding U3Si2 fuel and FeCrAl cladding

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yongfeng [Idaho National Laboratory

    2016-09-01

    U3Si2 and FeCrAl have been proposed as fuel and cladding concepts, respectively, for accident tolerance fuels with higher tolerance to accident scenarios compared to UO2. However, a lot of key physics and material properties regarding their in-pile performance are yet to be explored. To accelerate the understanding and reduce the cost of experimental studies, multiscale modeling and simulation are used to develop physics-based materials models to assist engineering scale fuel performance modeling. In this report, the lower-length-scale efforts in method and material model development supported by the Accident Tolerance Fuel (ATF) high-impact-problem (HIP) under the NEAMS program are summarized. Significant progresses have been made regarding interatomic potential, phase field models for phase decomposition and gas bubble formation, and thermal conductivity for U3Si2 fuel, and precipitation in FeCrAl cladding. The accomplishments are very useful by providing atomistic and mesoscale tools, improving the current understanding, and delivering engineering scale models for these two ATF concepts.

  12. Mechanical Behavior of UO2 at Sub-grain Length Scales: Quantification of Elastic, Plastic and Creep Properties via Microscale Testing

    Energy Technology Data Exchange (ETDEWEB)

    Peralta, Pedro

    2018-04-16

    Techniques were developed to measure properties at sub-grain scales using depleted Uranium Oxide (d-UO2) samples heat-treated to obtain different grain sizes and oxygen stoichiometries, through three main tasks: 1) sample processing and characterization, 2) microscale and conventional testing and 3) modeling. Grain size and crystallography were characterized using Scanning Electron Microscopy (SEM), in conjunction with Electron Backscattering Diffraction (EBSD) and Electron Channeling Contrast Imaging (ECCI). Grains were then carefully selected based on their crystallographic orientations to perform ex-situ micromechanical tests with samples machined via Focused Ion Beam (FIB), with emphasis on micro-cantilever bending. These experiments were performed under controlled atmospheres, to insure stoichiometry control, at temperatures up to 700 °C and allowed measurements involving elastic (effective Young’s modulus), plastic (critical resolved shear stresses) and creep (creep strain rates) behavior. Conventional compression experiments were performed simultaneously to compare with the ex-situ measurements and study potential size effects. Modeling was implemented using anisotropic elasticity and inelastic constitutive relations for plasticity and creep based on kinematics and kinetics of dislocation glide that account for the effects of crystal orientation, and stress. The models will be calibrated and validated using the experimental data. This project provided insight on correlations among stoichiometry, crystallography and mechanical behavior in advanced oxide fuels, provided valuable experimental data to validate and calibrate mesoscale fuel performance codes and also a framework to measure sub-grain scale mechanical properties that should be suitable for use with irradiated samples due to small volumes required. The goals and metrics of the ongoing study of thermo-mechanical behavior in depleted uranium dioxide (d-UO2) outlined in this project have been

  13. Influence of day length and temperature on the content of health-related compounds in broccoli (Brassica oleracea L. var. italica).

    Science.gov (United States)

    Steindal, Anne Linn Hykkerud; Mølmann, Jørgen; Bengtsson, Gunnar B; Johansen, Tor J

    2013-11-13

    Vegetables grown at different latitudes are exposed to various temperatures and day lengths, which can affect the content of health- and sensory-related compounds in broccoli florets. A 2 × 2 factorial experiment was conducted under controlled growth conditions, with contrasting temperatures (15/9 and 21/15 °C) and day lengths (12 and 24 h), to investigate the effect on glucosinolates, vitamin C, flavonols, and soluble sugars. Aliphatic glucosinolates, quercetin, and kaempferol were at their highest levels at high temperatures combined with a 12 h day. Levels of total glucosinolates, d-glucose, and d-fructose were elevated by high temperatures. Conversely, the content of vitamin C was highest with a 12 h day length combined with 15/9 °C. Our results indicate that temperature and day length influence the contents of health-related compounds in broccoli florets in a complex way, suggesting no general superiority of any of the contrasting growth conditions.

  14. Regional-scale risk assessment methodology using the Relative ...

    African Journals Online (AJOL)

    2012-04-18

    Scale Risk Assessment is implemented on a large spatial scale and facilitates the consideration of multiple sources of multiple stressors affecting multiple endpoints, including the ecosystem dynamics and characteristics of.

  15. Vortex matter beyond SANS. Neutron studies of vortex structures covering a length scale of 0.01 ti 10 μm

    Energy Technology Data Exchange (ETDEWEB)

    Reimann, Tommy

    2017-01-09

    This thesis is concerned with different generic types of vortex matter arising in the intermediate state of the type-I superconductor lead, the intermediate mixed state of the type-II superconductor niobium, and the helimagnetic phase of the compound manganese silicide. It is demonstrated and explained how a combination of i) the radiographic techniques neutron grating interferometry and neutron diffractive imaging with ii) scattering methods such as small-angle-neutron scattering and ultra-small-angle neutron scattering can provide novel insight into the bulk behavior of these vortex systems. By means of the used scattering methods, detailed information on the morphology of the vortex phases covering a length scale of 0.01 to 10 μm are obtained, while the radiographic approaches additionally map the spatial distribution of vortices within the sample. In particular, this thesis focuses on the strong influences of demagnetization, geometric barriers and pinning on the vortex configuration.

  16. Vortex matter beyond SANS. Neutron studies of vortex structures covering a length scale of 0.01 ti 10 μm

    International Nuclear Information System (INIS)

    Reimann, Tommy

    2017-01-01

    This thesis is concerned with different generic types of vortex matter arising in the intermediate state of the type-I superconductor lead, the intermediate mixed state of the type-II superconductor niobium, and the helimagnetic phase of the compound manganese silicide. It is demonstrated and explained how a combination of i) the radiographic techniques neutron grating interferometry and neutron diffractive imaging with ii) scattering methods such as small-angle-neutron scattering and ultra-small-angle neutron scattering can provide novel insight into the bulk behavior of these vortex systems. By means of the used scattering methods, detailed information on the morphology of the vortex phases covering a length scale of 0.01 to 10 μm are obtained, while the radiographic approaches additionally map the spatial distribution of vortices within the sample. In particular, this thesis focuses on the strong influences of demagnetization, geometric barriers and pinning on the vortex configuration.

  17. Large Scale Obscuration and Related Climate Effects Workshop: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Zak, B.D.; Russell, N.A.; Church, H.W.; Einfeld, W.; Yoon, D.; Behl, Y.K. [eds.

    1994-05-01

    A Workshop on Large Scale Obsurcation and Related Climate Effects was held 29--31 January, 1992, in Albuquerque, New Mexico. The objectives of the workshop were: to determine through the use of expert judgement the current state of understanding of regional and global obscuration and related climate effects associated with nuclear weapons detonations; to estimate how large the uncertainties are in the parameters associated with these phenomena (given specific scenarios); to evaluate the impact of these uncertainties on obscuration predictions; and to develop an approach for the prioritization of further work on newly-available data sets to reduce the uncertainties. The workshop consisted of formal presentations by the 35 participants, and subsequent topical working sessions on: the source term; aerosol optical properties; atmospheric processes; and electro-optical systems performance and climatic impacts. Summaries of the conclusions reached in the working sessions are presented in the body of the report. Copies of the transparencies shown as part of each formal presentation are contained in the appendices (microfiche).

  18. EXPERIMENTAL INVESTIGATION OF RELATIVE PERMEABILITY UPSCALING FROM THE MICRO-SCALE TO THE MACRO-SCALE

    Energy Technology Data Exchange (ETDEWEB)

    Laura J. Pyrak-Nolte; Ping Yu; JiangTao Cheng; Daiquan Chen; Nicholas Giordano; Mirela Mustata; John Coy; Nathan Cooper; David D. Nolte

    2002-12-01

    The principal challenge of upscaling techniques for multi-phase fluid dynamics in porous media is to determine which properties on the micro-scale can be used to predict macroscopic flow and spatial distribution of phases at core- and field-scales. The most notable outcome of recent theories is the identification of interfacial areas per volume for multiple phases as a fundamental parameter that determines much of the multi-phase properties of the porous medium. A formal program of experimental research was begun to directly test upscaling theories in fluid flow through porous media by comparing measurements of relative permeability and capillary-saturation with measurements of interfacial area per volume. During this reporting period, we have shown experimentally that the coherence detection can be performed in a borescope. The measurement of interfacial area per volume (IAV), capillary pressure and saturation in two dimensional micro-models structures has shown the existence of a unique relationship among these hydraulic parameters for different pore geometry. The measurement of interfacial area per volume on a three-dimensional natural sample, i.e., sandstone, is essentially completed for imbibition conditions.

  19. Fundamental length and relativistic length

    International Nuclear Information System (INIS)

    Strel'tsov, V.N.

    1988-01-01

    It si noted that the introduction of fundamental length contradicts the conventional representations concerning the contraction of the longitudinal size of fast-moving objects. The use of the concept of relativistic length and the following ''elongation formula'' permits one to solve this problem

  20. Method Specific Calibration Corrects for DNA Extraction Method Effects on Relative Telomere Length Measurements by Quantitative PCR.

    Science.gov (United States)

    Seeker, Luise A; Holland, Rebecca; Underwood, Sarah; Fairlie, Jennifer; Psifidi, Androniki; Ilska, Joanna J; Bagnall, Ainsley; Whitelaw, Bruce; Coffey, Mike; Banos, Georgios; Nussey, Daniel H

    2016-01-01

    Telomere length (TL) is increasingly being used as a biomarker in epidemiological, biomedical and ecological studies. A wide range of DNA extraction techniques have been used in telomere experiments and recent quantitative PCR (qPCR) based studies suggest that the choice of DNA extraction method may influence average relative TL (RTL) measurements. Such extraction method effects may limit the use of historically collected DNA samples extracted with different methods. However, if extraction method effects are systematic an extraction method specific (MS) calibrator might be able to correct for them, because systematic effects would influence the calibrator sample in the same way as all other samples. In the present study we tested whether leukocyte RTL in blood samples from Holstein Friesian cattle and Soay sheep measured by qPCR was influenced by DNA extraction method and whether MS calibration could account for any observed differences. We compared two silica membrane-based DNA extraction kits and a salting out method. All extraction methods were optimized to yield enough high quality DNA for TL measurement. In both species we found that silica membrane-based DNA extraction methods produced shorter RTL measurements than the non-membrane-based method when calibrated against an identical calibrator. However, these differences were not statistically detectable when a MS calibrator was used to calculate RTL. This approach produced RTL measurements that were highly correlated across extraction methods (r > 0.76) and had coefficients of variation lower than 10% across plates of identical samples extracted by different methods. Our results are consistent with previous findings that popular membrane-based DNA extraction methods may lead to shorter RTL measurements than non-membrane-based methods. However, we also demonstrate that these differences can be accounted for by using an extraction method-specific calibrator, offering researchers a simple means of accounting for

  1. Drosophila Full-Length Amyloid Precursor Protein Is Required for Visual Working Memory and Prevents Age-Related Memory Impairment.

    Science.gov (United States)

    Rieche, Franziska; Carmine-Simmen, Katia; Poeck, Burkhard; Kretzschmar, Doris; Strauss, Roland

    2018-03-05

    The β-amyloid precursor protein (APP) plays a central role in the etiology of Alzheimer's disease (AD). However, its normal physiological functions are still unclear. APP is cleaved by various secretases whereby sequential processing by the β- and γ-secretases produces the β-amyloid peptide that is accumulating in plaques that typify AD. In addition, this produces secreted N-terminal sAPPβ fragments and the APP intracellular domain (AICD). Alternative cleavage by α-secretase results in slightly longer secreted sAPPα fragments and the identical AICD. Whereas the AICD has been connected with transcriptional regulation, sAPPα fragments have been suggested to have a neurotrophic and neuroprotective role [1]. Moreover, expression of sAPPα in APP-deficient mice could rescue their deficits in learning, spatial memory, and long-term potentiation [2]. Loss of the Drosophila APP-like (APPL) protein impairs associative olfactory memory formation and middle-term memory that can be rescued with a secreted APPL fragment [3]. We now show that APPL is also essential for visual working memory. Interestingly, this short-term memory declines rapidly with age, and this is accompanied by enhanced processing of APPL in aged flies. Furthermore, reducing secretase-mediated proteolytic processing of APPL can prevent the age-related memory loss, whereas overexpression of the secretases aggravates the aging effect. Rescue experiments confirmed that this memory requires signaling of full-length APPL and that APPL negatively regulates the neuronal-adhesion molecule Fasciclin 2. Overexpression of APPL or one of its secreted N termini results in a dominant-negative interaction with the FASII receptor. Therefore, our results show that specific memory processes require distinct APPL products. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Shorter Leukocyte Telomere Length in Relation to Presumed Nonalcoholic Fatty Liver Disease in Mexican-American Men in NHANES 1999–2002

    Directory of Open Access Journals (Sweden)

    Janet M. Wojcicki

    2017-01-01

    Full Text Available Leukocyte telomere length is shorter in response to chronic disease processes associated with inflammation such as diabetes mellitus and coronary artery disease. Data from the National Health and Nutrition Examination Survey (NHANES from 1999 to 2002 was used to explore the relationship between leukocyte telomere length and presumed NAFLD, as indicated by elevated serum alanine aminotransferase (ALT levels, obesity, or abdominal obesity. Logistic regression models were used to evaluate the relationship between telomere length and presumed markers of NAFLD adjusting for possible confounders. There was no relationship between elevated ALT levels, abdominal obesity, or obesity and telomere length in adjusted models in NHANES (OR 1.13, 95% CI 0.48–2.65; OR 1.17, 95% CI 0.52–2.62, resp.. Mexican-American men had shorter telomere length in relation to presumed NAFLD (OR 0.07, 95% CI 0.006–0.79 and using different indicators of NAFLD (OR 0.012, 95% CI 0.0006–0.24. Mexican origin with presumed NAFLD had shorter telomere length than men in other population groups. Longitudinal studies are necessary to evaluate the role of telomere length as a potential predictor to assess pathogenesis of NALFD in Mexicans.

  3. Flame Length

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Flame length was modeled using FlamMap, an interagency fire behavior mapping and analysis program that computes potential fire behavior characteristics. The tool...

  4. Predictors of extended length of stay, discharge to inpatient rehab, and hospital readmission following elective lumbar spine surgery: introduction of the Carolina-Semmes Grading Scale.

    Science.gov (United States)

    McGirt, Matthew J; Parker, Scott L; Chotai, Silky; Pfortmiller, Deborah; Sorenson, Jeffrey M; Foley, Kevin; Asher, Anthony L

    2017-10-01

    OBJECTIVE Extended hospital length of stay (LOS), unplanned hospital readmission, and need for inpatient rehabilitation after elective spine surgery contribute significantly to the variation in surgical health care costs. As novel payment models shift the risk of cost overruns from payers to providers, understanding patient-level risk of LOS, readmission, and inpatient rehabilitation is critical. The authors set out to develop a grading scale that effectively stratifies risk of these costly events after elective surgery for degenerative lumbar pathologies. METHODS The Quality and Outcomes Database (QOD) registry prospectively enrolls patients undergoing surgery for degenerative lumbar spine disease. This registry was queried for patients who had undergone elective 1- to 3-level lumbar surgery for degenerative spine pathology. The association between preoperative patient variables and extended postoperative hospital LOS (LOS ≥ 7 days), discharge status (inpatient facility vs home), and 90-day hospital readmission was assessed using stepwise multivariate logistic regression. The Carolina-Semmes grading scale was constructed using the independent predictors for LOS (0-12 points), discharge to inpatient facility (0-18 points), and 90-day readmission (0-6 points), and its performance was assessed using the QOD data set. The performance of the grading scale was then confirmed separately after using it in 2 separate neurosurgery practice sites (Carolina Neurosurgery & Spine Associates [CNSA] and Semmes Murphey Clinic). RESULTS A total of 6921 patients were analyzed. Overall, 290 (4.2%) patients required extended LOS, 654 (9.4%) required inpatient facility care/rehabilitation on hospital discharge, and 474 (6.8%) were readmitted to the hospital within 90 days postdischarge. Variables that remained as independently associated with these unplanned events in multivariate analysis included age ≥ 70 years, American Society of Anesthesiologists Physical Classification System

  5. Charge Separation in Intermixed Polymer:PC70BM Photovoltaic Blends: Correlating Structural and Photophysical Length Scales as a Function of Blend Composition

    KAUST Repository

    Utzat, Hendrik

    2017-04-24

    A key challenge in achieving control over photocurrent generation by bulk-heterojunction organic solar cells is understanding how the morphology of the active layer impacts charge separation and in particular the separation dynamics within molecularly intermixed donor-acceptor domains versus the dynamics between phase-segregated domains. This paper addresses this issue by studying blends and devices of the amorphous silicon-indacenodithiophene polymer SiIDT-DTBT and the acceptor PCBM. By changing the blend composition, we modulate the size and density of the pure and intermixed domains on the nanometer length scale. Laser spectroscopic studies show that these changes in morphology correlate quantitatively with the changes in charge separation dynamics on the nanosecond time scale and with device photocurrent densities. At low fullerene compositions, where only a single, molecularly intermixed polymer-fullerene phase is observed, photoexcitation results in a ∼ 30% charge loss from geminate polaron pair recombination, which is further studied via light intensity experiments showing that the radius of the polaron pairs in the intermixed phase is 3-5 nm. At high fullerene compositions (≥67%), where the intermixed domains are 1-3 nm and the pure fullerene phases reach ∼4 nm, the geminate recombination is suppressed by the reduction of the intermixed phase, making the fullerene domains accessible for electron escape.

  6. A study of small-scale foliation in lengths of core enclosing fault zones in borehole WD-3, Permit Area D, Lac du Bonnet Batholith

    Energy Technology Data Exchange (ETDEWEB)

    Ejeckam, R.B.

    1992-12-01

    Small-scale foliation measurements in lengths of core from borehole WD-3 of Permit Area D of the Lac du Bonnet Batholith have defined five major mean orientation sets. They strike NW, N and NE. The orientations (strike to the left of the dip direction/dip) of these sets are as follows: Set I - 028/74 deg; II - 001/66 deg; III - 100/58 deg; IV - 076/83 deg; and V - 210/40 deg. The small-scale foliations were defined by different mineral types such as biotite crystals, plagioclase, mineral banding and quartz lenses. Well-developed biotite foliation is commonly present whenever well-developed plagioclase foliation exists, but as the strength of development weakens, the preferred orientations of plagioclase foliation do not correspond to those of biotite. It is also noted that the foliations appear to strike in directions orthogonal to the fractures in the fracture zones in the same depth interval. No significant change in foliation orientation was observed in Zones I to IV. Set V, however, whose mean orientation is 210/40 deg, is absent from the Zone IV interval, ranging from 872 to 905 m. (auth)

  7. ISM and dynamical scaling relations in the local Universe

    Science.gov (United States)

    Cortese, L.

    2016-06-01

    In the last decade we have seen a tremendous progress in our understanding of the life cycle of galaxies. Particularly powerful has been the synergy between representative surveys of cold gas, dust and metals and improved theoretical models able to follow the evolution of the different phases of the ISM in a self-consistent way. At the same time, the advent of optical integral field spectroscopic surveys is finally allowing us to quantify how the kinematical properties of gas and stars vary across the Hubble sequence. In this talk, I will review recent observational work aimed at providing a local benchmark for the study of the star formation cycle in galaxies and dynamical scaling relations in galaxies. By combining observations obtained as part the Herschel Reference Survey, the GALEX Arecibo SDSS survey, the ALFALFA survey and the SAMI Galaxy Survey, I will discuss what nearby galaxies can teach us about the interplay between kinematics, star formation, chemical enrichment and environmental effects in our neighbourhoods.

  8. Long length scales of element transport during reaction texture development in orthoamphibole-cordierite gneiss: Thor-Odin dome, British Columbia, Canada

    Science.gov (United States)

    Goergen, Eric T.; Whitney, Donna L.

    2012-02-01

    First-order factors controlling the textural and chemical evolution of metamorphic rocks are bulk composition and pressure-temperature-time ( P- T- t) path. Although it is common to assume that major element bulk composition does not change during regional metamorphism, rocks with reaction textures such as corona structures record evidence for major changes in effective bulk composition (EBC) and therefore provide significant insight into the scale, pathways, and mechanisms of element transport during metamorphism. Quantifying changes in EBC is essential for petrologic applications such as calculation of phase diagrams (pseudosections). The progressive growth of complex corona structures on garnet and Al2SiO5 porphyroblasts in orthoamphibole-cordierite gneiss Thor-Odin dome (British Columbia, Canada) reduced the EBC volume of the rock during metamorphism and therefore had a dramatic effect on the evolution of the stable mineral assemblage. These rocks contain a chemical and textural record of metamorphic reactions and preserve 3D networks (reaction pathways) connecting corona structures. These coronal networks record long (>cm) length scales of localized element transport during metamorphism. P- T, T- X, and P- X pseudosections are used to investigate the control of effective bulk composition on phase assemblage evolution. Despite textural complexity and evidence for disequilibrium, mineral assemblages and compositions were successfully modeled and peak metamorphic conditions estimated at 750°C and 9 kbar. These results illustrate how textural and chemical changes during metamorphism can be evaluated using an integrated petrographic and pseudosection approach, highlight the importance of effective bulk composition choice for application of phase equilibria methods in metamorphic rocks, and show how corona structures can be used to understand the scale of compositional change and element transport during metamorphism.

  9. The Impact of Host Family Relations and Length of Stay on Adolescent Identity Expression during Study Abroad

    Science.gov (United States)

    Grieve, Averil Marie

    2015-01-01

    This study focuses on the relationships between host family success, social integration, length of stay and acquisition of adolescent language by students on extended international homestay programmes. Degree of adolescent language acquisition and integration is measured by use of two hallmarks of adolescent language: markers of approximation…

  10. Leukocyte telomere length associates with prospective mortality independent of immune-related parameters and known genetic markers

    NARCIS (Netherlands)

    J. Deelen (Joris); M. Beekman (Marian); V. Codd (Veryan); S. Trompet (Stella); L. Broer (Linda); S. Hägg (Sara); K. Fischer (Krista); P.E. Thijssen (Peter); H.E.D. Suchiman (Eka); D. Postmus (Douwe); A.G. Uitterlinden (André); A. Hofman (Albert); A.J. de Craen (Anton); A. Metspalu (Andres); N.L. Pedersen (Nancy); C.M. van Duijn (Cornelia); J.W. Jukema (Jan Wouter); J.J. Houwing-Duistermaat (Jeanine); N.J. Samani (Nilesh); P.E. Slagboom (Eline)

    2014-01-01

    textabstractBackground: Human leukocyte telomere length (LTL) decreases with age and shorter LTL has previously been associated with increased prospective mortality. However, it is not clear whether LTL merely marks the health status of an individual by its association with parameters of immune

  11. Rapid detection of dihydropteroate polymorphism in AIDS-related Pneumocystis carinii pneumonia by restriction fragment length polymorphism

    DEFF Research Database (Denmark)

    Helweg-Larsen, J; Eugen-Olsen, J; Lundgren, B

    2000-01-01

    are associated with failure of sulpha prophylaxis and increased mortality in HIV-1 positive patients with PCP, suggesting that DHPS mutations may cause sulpha resistance. To facilitate detection of DHPS mutations we developed a restriction fragment length polymorphism (RFLP) assay, detecting mutations at codon...

  12. Correlations of properties and structures at different length scales of hydro- and organo-gels based on N-alkyl-(R)-12-hydroxyoctadecylammonium chlorides.

    Science.gov (United States)

    Mallia, V Ajay; Terech, Pierre; Weiss, Richard G

    2011-11-03

    The self-assembly and gelating ability of a set of N-alkyl-(R)-12-hydroxyoctadecylammonium chlorides (NCl-n, where n = 0-6, 18 is the length of the alkyl chain on nitrogen) are described. Several are found to be ambidextrous (gelating both water and a variety of organic liquids) and very efficient (needing less than ca. 0.5 wt % at room temperature). Structure-property correlations at different distance scales of the NCl-n in their hydro- and organo-gels and neat, solid states have been made using X-ray diffraction, neutron scattering, thermal, optical, cryo-SEM and rheological techniques. The self-assembled fibrillar networks consist of spherulitic objects with fibers whose diameters and degrees of twisting differ in the hydro- and organo-gels. Increasing n (and, thus, the molecular length) increases the width of the fibers in their hydrogels; an irregular, less pronounced trend between n and fiber width is observed in the corresponding toluene gels. Time-dependent, small angle neutron scattering data for the isothermal sol-to-gel transformation of sols of NCl-18/toluene to their gels, treated according to Avrami theory, indicate heterogeneous nucleation involving rodlike growth. Rheological studies of gels of NCl-3 in water and toluene confirm their viscoelastic nature and show that the hydrogel is mechanically stronger than the toluene gel. Models for the different molecular packing arrangements within the fibrillar gel networks of the hydro- and organogels have been inferred from X-ray diffraction. The variations in the fibrillar networks provide a comprehensive picture and detailed insights into why seemingly very similar NCl-n behave very differently during their self-assembly processes in water and organic liquids. It is shown that the NCl-n provide a versatile platform for interrogating fundamental questions regarding the links between molecular structure and one-dimensional self-aggregation, leading to gelation.

  13. Optimal smoothing length scale for actuator line models of wind turbine blades based on Gaussian body force distribution: Wind energy, actuator line model

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Tossas, L. A. [Department of Mechanical Engineering, Johns Hopkins University, Baltimore 21218 MD USA; Churchfield, M. J. [National Renewable Energy Laboratory, Golden 80401 CO USA; Meneveau, C. [Department of Mechanical Engineering, Johns Hopkins University, Baltimore 21218 MD USA

    2017-01-20

    The actuator line model (ALM) is a commonly used method to represent lifting surfaces such as wind turbine blades within large-eddy simulations (LES). In the ALM, the lift and drag forces are replaced by an imposed body force that is typically smoothed over several grid points using a Gaussian kernel with some prescribed smoothing width e. To date, the choice of e has most often been based on numerical considerations related to the grid spacing used in LES. However, especially for finely resolved LES with grid spacings on the order of or smaller than the chord length of the blade, the best choice of e is not known. In this work, a theoretical approach is followed to determine the most suitable value of e, based on an analytical solution to the linearized inviscid flow response to a Gaussian force. We find that the optimal smoothing width eopt is on the order of 14%-25% of the chord length of the blade, and the center of force is located at about 13%-26% downstream of the leading edge of the blade for the cases considered. These optimal values do not depend on angle of attack and depend only weakly on the type of lifting surface. It is then shown that an even more realistic velocity field can be induced by a 2-D elliptical Gaussian lift-force kernel. Some results are also provided regarding drag force representation.

  14. New SCALE-4 features related to cross-section processing

    International Nuclear Information System (INIS)

    Petrie, L.M.; Landers, N.F.; Greene, N.M.; Parks, C.V.

    1991-01-01

    The SCALE code system has a standardized scheme for processing problem-dependent cross section from problem-independent waste libraries. Some improvements and new capabilities in the processing scheme have been incorporated into the new Version 4 release of the SCALE system. The new features include the capability to consider annular cylindrical and spherical unit cells, and improved Dancoff factor formulation, and changes to the NITAWL-II module to perform resonance self-shielding with reference to infinite dilute values. A review of these major changes in the cross-section processing scheme for SCALE-4 is presented in this paper

  15. Regional scale ecological risk assessment: using the relative risk model

    National Research Council Canada - National Science Library

    Landis, Wayne G

    2005-01-01

    ...) in the performance of regional-scale ecological risk assessments. The initial chapters present the methodology and the critical nature of the interaction between risk assessors and decision makers...

  16. Calculation of large scale relative permeabilities from stochastic properties of the permeability field and fluid properties

    Energy Technology Data Exchange (ETDEWEB)

    Lenormand, R.; Thiele, M.R. [Institut Francais du Petrole, Rueil Malmaison (France)

    1997-08-01

    The paper describes the method and presents preliminary results for the calculation of homogenized relative permeabilities using stochastic properties of the permeability field. In heterogeneous media, the spreading of an injected fluid is mainly sue to the permeability heterogeneity and viscosity fingering. At large scale, when the heterogeneous medium is replaced by a homogeneous one, we need to introduce a homogenized (or pseudo) relative permeability to obtain the same spreading. Generally, is derived by using fine-grid numerical simulations (Kyte and Berry). However, this operation is time consuming and cannot be performed for all the meshes of the reservoir. We propose an alternate method which uses the information given by the stochastic properties of the field without any numerical simulation. The method is based on recent developments on homogenized transport equations (the {open_quotes}MHD{close_quotes} equation, Lenormand SPE 30797). The MHD equation accounts for the three basic mechanisms of spreading of the injected fluid: (1) Dispersive spreading due to small scale randomness, characterized by a macrodispersion coefficient D. (2) Convective spreading due to large scale heterogeneities (layers) characterized by a heterogeneity factor H. (3) Viscous fingering characterized by an apparent viscosity ration M. In the paper, we first derive the parameters D and H as functions of variance and correlation length of the permeability field. The results are shown to be in good agreement with fine-grid simulations. The are then derived a function of D, H and M. The main result is that this approach lead to a time dependent . Finally, the calculated are compared to the values derived by history matching using fine-grid numerical simulations.

  17. [The evaluation of the end-ejection pressure-length relation as an index of regional contractility].

    Science.gov (United States)

    Perlini, S; Meyer, T E; Bernardi, L; Soldà, P L; Calciati, A; Finardi, G; Foëx, P

    1992-08-01

    Although end-systolic pressure-length relationship (ESPLR) is now widely used as a regional substitute for the end-systolic pressure-volume relationship, there are some reservations about its use as an index of systolic performance. This study aimed at assessing whether by using end-ejection (zero aortic flow) as a definition of end-systole, ESPLR can be used to characterize myocardial performance independent of load, and if the choice of the region where to implant the sonomicrometers is critical. Ten anaesthetized dogs (16 +/- 2 kg) were instrumented with a left ventricular (LV) pressure micromanometer and an aortic flow probe. Sonomicrometers were implanted in the apical (L1) and the mid-ventricular (L2) regions of the anterior LV wall, and in the basal region of the lateral wall (L3). End-systolic pressure-length relationships were obtained during acute preload reduction induced by the inflation of a vena caval balloon. This evaluation was repeated after increasing end-diastolic pressure to 14-18 mmHg (delta PL), after increasing systolic pressure by 15 (delta P-I) and 25 mmHg (delta P-II) with graded descending aorta occlusion, and during dobutamine infusions at 2.5 (Db 2.5) and 5 micrograms/kg/min (Db5). End-systolic pressure-length relationships (r > 0.97; pressure range: 70-100 mmHg) were characterized by their slopes (Ees), the extrapolated intercept at zero pressure (L0) and the values of segment length at a pressure of 75 (L75) and 100 mmHg (L100). In all the myocardial regions studied by sonomicrometry, the increments in preload and afterload did not significantly shift ESPLR.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Correlation of Leukocyte Telomere Length Measurement Methods in Patients with Dyskeratosis Congenita and in Their Unaffected Relatives

    OpenAIRE

    Khincha, Payal P.; Dagnall, Casey L.; Hicks, Belynda; Jones, Kristine; Aviv, Abraham; Kimura, Masayuki; Katki, Hormuzd; Aubert, Geraldine; Giri, Neelam; Alter, Blanche P.; Savage, Sharon A.; Gadalla, Shahinaz M.

    2017-01-01

    Several methods have been employed to measure telomere length (TL) in human studies. It has been difficult to directly compare the results from these studies because of differences in the laboratory techniques and output parameters. We compared TL measurements (TLMs) by the three most commonly used methods, quantitative polymerase chain reaction (qPCR), flow cytometry with fluorescence in situ hybridization (flow FISH) and Southern blot, in a cohort of patients with the telomere biology disor...

  19. Umbilical Cord Serum 25-Hydroxyvitamin D Concentrations and Relation to Birthweight, Head Circumference and Infant Length at Age 14 Days

    DEFF Research Database (Denmark)

    Dalgård, Christine; Petersen, Maria Skaalum; Steuerwald, Ulrike

    2016-01-01

    BACKGROUND: Insufficient supply of vitamin D during early development may negatively affect offspring growth. METHODS: We examined the association between umbilical cord (UC) serum 25-hydroxyvitamin D (25(OH)D) concentrations and infant size in a study of two Faroese birth cohorts of 1038 singleton...... with vitamin D status 50 nmol/L in models further adjusted for birthweight. CONCLUSION: Our data suggest that umbilical cord serum 25(OH)D concentrations are positively associated with infant length...

  20. Relative testis size and sperm morphometry across mammals: no evidence for an association between sperm competition and sperm length.

    OpenAIRE

    Gage, Matthew J G; Freckleton, Robert P

    2003-01-01

    Understanding why there is extensive variation in sperm form and function across taxa has been a challenge because sperm are specialized cells operating at a microscopic level in a complex environment. This comparative study collates published data to determine whether the evolution of sperm morphometry (sperm total length and separate component dimensions) is associated with sperm competition (when different males' sperm mix and compete for a female's ova) across 83 mammalian species. We use...

  1. Multi-length scale tomography for the determination and optimization of the effective microstructural properties in novel hierarchical solid oxide fuel cell anodes

    Science.gov (United States)

    Lu, Xuekun; Taiwo, Oluwadamilola O.; Bertei, Antonio; Li, Tao; Li, Kang; Brett, Dan J. L.; Shearing, Paul R.

    2017-11-01

    Effective microstructural properties are critical in determining the electrochemical performance of solid oxide fuel cells (SOFCs), particularly when operating at high current densities. A novel tubular SOFC anode with a hierarchical microstructure, composed of self-organized micro-channels and sponge-like regions, has been fabricated by a phase inversion technique to mitigate concentration losses. However, since pore sizes span over two orders of magnitude, the determination of the effective transport parameters using image-based techniques remains challenging. Pioneering steps are made in this study to characterize and optimize the microstructure by coupling multi-length scale 3D tomography and modeling. The results conclusively show that embedding finger-like micro-channels into the tubular anode can improve the mass transport by 250% and the permeability by 2-3 orders of magnitude. Our parametric study shows that increasing the porosity in the spongy layer beyond 10% enhances the effective transport parameters of the spongy layer at an exponential rate, but linearly for the full anode. For the first time, local and global mass transport properties are correlated to the microstructure, which is of wide interest for rationalizing the design optimization of SOFC electrodes and more generally for hierarchical materials in batteries and membranes.

  2. Derivation of effective fission gas diffusivities in UO2 from lower length scale simulations and implementation of fission gas diffusion models in BISON

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Anders David Ragnar [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pastore, Giovanni [Idaho National Lab. (INL), Idaho Falls, ID (United States); Liu, Xiang-Yang [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Perriot, Romain Thibault [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tonks, Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States); Stanek, Christopher Richard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-11-07

    This report summarizes the development of new fission gas diffusion models from lower length scale simulations and assessment of these models in terms of annealing experiments and fission gas release simulations using the BISON fuel performance code. Based on the mechanisms established from density functional theory (DFT) and empirical potential calculations, continuum models for diffusion of xenon (Xe) in UO2 were derived for both intrinsic conditions and under irradiation. The importance of the large XeU3O cluster (a Xe atom in a uranium + oxygen vacancy trap site with two bound uranium vacancies) is emphasized, which is a consequence of its high mobility and stability. These models were implemented in the MARMOT phase field code, which is used to calculate effective Xe diffusivities for various irradiation conditions. The effective diffusivities were used in BISON to calculate fission gas release for a number of test cases. The results are assessed against experimental data and future directions for research are outlined based on the conclusions.

  3. Characteristic length scale of the magnon accumulation in Fe{sub 3}O{sub 4}/Pt bilayer structures by incoherent thermal excitation

    Energy Technology Data Exchange (ETDEWEB)

    Anadón, A., E-mail: anadonb@unizar.es; Lucas, I.; Morellón, L. [Instituto de Nanociencia de Aragón, Universidad de Zaragoza, E-50018 Zaragoza (Spain); Departamento de Física de la Materia Condensada, Universidad de Zaragoza, E-50009 Zaragoza (Spain); Ramos, R. [WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Spin Quantum Rectification Project, ERATO, Japan Science and Technology Agency, Sendai 980-8577 (Japan); Algarabel, P. A. [Departamento de Física de la Materia Condensada, Universidad de Zaragoza, E-50009 Zaragoza (Spain); Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza and Consejo Superior de Investigaciones Científicas, 50009 Zaragoza (Spain); Ibarra, M. R.; Aguirre, M. H. [Instituto de Nanociencia de Aragón, Universidad de Zaragoza, E-50018 Zaragoza (Spain); Departamento de Física de la Materia Condensada, Universidad de Zaragoza, E-50009 Zaragoza (Spain); Laboratorio de Microscopías avanzadas, Universidad de Zaragoza, 50018 Zaragoza (Spain)

    2016-07-04

    The dependence of Spin Seebeck effect (SSE) with the thickness of the magnetic materials is studied by means of incoherent thermal excitation. The SSE voltage signal in Fe{sub 3}O{sub 4}/Pt bilayer structure increases with the magnetic material thickness up to 100 nm, approximately, showing signs of saturation for larger thickness. This dependence is well described in terms of a spin current pumped in the platinum film by the magnon accumulation in the magnetic material. The spin current is generated by a gradient of temperature in the system and detected by the Pt top contact by means of inverse spin Hall effect. Calculations in the frame of the linear response theory adjust with a high degree of accuracy the experimental data, giving a thermal length scale of the magnon accumulation (Λ) of 17 ± 3 nm at 300 K and Λ = 40 ± 10 nm at 70 K.

  4. Allometric relations of total volumes of prolactin cells and corticotropic cells to body length in the annual cyprinodont Cynolebias whitei: effects of environmental salinity, stress and ageing

    NARCIS (Netherlands)

    Ruijter, J. M.; Wendelaar Bonga, S. E.

    1987-01-01

    An analysis of the allometric relations of the total volumes occupied by prolactin (PRL) and corticotropic (ACTH) cells (PRL volume and ACTH volume, respectively) to body length and a study of the immunocytochemical staining intensity of PRL and ACTH cells were used to determine the differences in

  5. Nano-scale structure in membranes in relation to enzyme action - computer simulation vs. experiment

    DEFF Research Database (Denmark)

    Høyrup, P.; Jørgensen, Kent; Mouritsen, O.G.

    2002-01-01

    lengths are in the nano-meter range. The nano-scale structure is believed to be important for controlling the activity of enzymes, specifically phospholipases, which act at bilayer membranes. We propose here a lattice-gas statistical mechanical model with appropriate dynamics to account for the non...

  6. Optimization of a Relative Telomere Length Assay by Monochromatic Multiplex Real-Time Quantitative PCR on the LightCycler 480: Sources of Variability and Quality Control Considerations.

    Science.gov (United States)

    Hsieh, Anthony Y Y; Saberi, Sara; Ajaykumar, Abhinav; Hukezalie, Kyle; Gadawski, Izabella; Sattha, Beheroze; Côté, Hélène C F

    2016-05-01

    Telomere length (TL) measurement is central to many biomedical research, population, and epidemiology studies, with promising potential as a clinical tool. Various assays are used to determine TL, depending on the type and size of the sample. We describe the detailed optimization of a monochromatic multiplex real-time quantitative PCR (MMqPCR) assay for relative TL using the LightCycler 480. MMqPCR was initially developed using a different instrument with many separate reagents. Differences in instrument performance, reagents, and workflow required substantial optimization for the assay to be compatible with the LightCycler 480. We optimized the chemistry of the assay using a purchased one-component reaction mix and herein describe sources of variability and quality control relevant to the MMqPCR TL assay on any instrument. Finally, the assay was validated against other TL assays, such as terminal restriction fragment, Southern blot, and flow fluorescent in situ hybridization. The correlations obtained between data from MMqPCR and these assays (R(2) = 0.88 and 0.81) were comparable to those seen with the monoplex version (R(2) = 0.85 and 0.82) when the same samples were assayed. The intrarun and interrun CV ranged from 4.2% to 6.2% and 3.2% to 4.9%, respectively. We describe a protocol for measuring TL on the LightCycler platform that provides a robust high-throughput method applicable to clinical diagnostics or large-scale studies of archived specimens. Copyright © 2016 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

  7. Scaling relation for determining the critical threshold for continuum ...

    Indian Academy of Sciences (India)

    We study continuum percolation of overlapping circular discs of two sizes. We propose a phenomenological scaling equation for the increase in the effective size of the larger discs due to the presence of the smaller discs. The critical percolation threshold as a function of the ratio of sizes of discs, for different values of the ...

  8. Scaling relations in large-Prandtl-number natural thermal convection

    NARCIS (Netherlands)

    Shishkina, Olga; Emran, Mohammad S.; Grossmann, Siegfried; Lohse, Detlef

    2017-01-01

    In this study, we follow Grossmann and Lohse [Phys. Rev. Lett. 86, 3316 (2001)10.1103/PhysRevLett.86.3316], who derived various scalings regimes for the dependence of the Nusselt number Nu and the Reynolds number Re on the Rayleigh number Ra and the Prandtl number Pr. We focus on theoretical

  9. Work Related Injuries and Associated Factors among Small Scale ...

    African Journals Online (AJOL)

    user

    Table 2: Occupational and behavioral characteristics of the respondents in small scale industries of Mizan-Aman town, Bench Maji zone, Southwest Ethiopia, 2016. Variable. Frequency (N=219). Percent (%). Consume alcohol. Yes. 87. 39.7. No. 132. 60.3. Smoke cigarettes. Yes. 58. 26.5. No. 161. 73.5. Sleeping disorder.

  10. Scaling relation for determining the critical threshold for continuum ...

    Indian Academy of Sciences (India)

    Abstract. We study continuum percolation of overlapping circular discs of two sizes. We propose a phenomenological scaling equation for the increase in the effective size of the larger discs due to the presence of the smaller discs. The critical percolation threshold as a function of the ratio of sizes of discs, for different values ...

  11. Scaling relation for determining the critical threshold for continuum ...

    Indian Academy of Sciences (India)

    We study continuum percolation of overlapping circular discs of two sizes. We propose a phenomenological scaling equation for the increase in the effective size of the larger discs due to the presence of the smaller ... We start by summarizing the qualitative arguments of [6]. Let us assume, without any loss of generality, that ...

  12. Longitudinal changes of telomere length and epigenetic age related to traumatic stress and post-traumatic stress disorder.

    Science.gov (United States)

    Boks, Marco P; van Mierlo, Hans C; Rutten, Bart P F; Radstake, Timothy R D J; De Witte, Lot; Geuze, Elbert; Horvath, Steve; Schalkwyk, Leonard C; Vinkers, Christiaan H; Broen, Jasper C A; Vermetten, Eric

    2015-01-01

    Several studies have reported an association between traumatic stress and telomere length suggesting that traumatic stress has an impact on ageing at the cellular level. A newly derived tool provides an additional means to investigate cellular ageing by estimating epigenetic age based on DNA methylation profiles. We therefore hypothesise that in a longitudinal study of traumatic stress both indicators of cellular ageing will show increased ageing. We expect that particularly in individuals that developed symptoms of post-traumatic stress disorder (PTSD) increases in these ageing parameters would stand out. From an existing longitudinal cohort study, ninety-six male soldiers were selected based on trauma exposure and the presence of symptoms of PTSD. All military personnel were deployed in a combat zone in Afghanistan and assessed before and 6 months after deployment. The Self-Rating Inventory for PTSD was used to measure the presence of PTSD symptoms, while exposure to combat trauma during deployment was measured with a 19-item deployment experiences checklist. These groups did not differ for age, gender, alcohol consumption, cigarette smoking, military rank, length, weight, or medication use. In DNA from whole blood telomere length was measured and DNA methylation levels were assessed using the Illumina 450K DNA methylation arrays. Epigenetic ageing was estimated using the DNAm age estimator procedure. The association of trauma with telomere length was in the expected direction but not significant (B=-10.2, p=0.52). However, contrary to our expectations, development of PTSD symptoms was associated with the reverse process, telomere lengthening (B=1.91, p=0.018). In concordance, trauma significantly accelerated epigenetic ageing (B=1.97, p=0.032) and similar to the findings in telomeres, development of PTSD symptoms was inversely associated with epigenetic ageing (B=-0.10, p=0.044). Blood cell count, medication and premorbid early life trauma exposure did not

  13. Step length after discrete perturbation predicts accidental falls and fall-related injury in elderly people with a range of peripheral neuropathy

    Science.gov (United States)

    Allet, L; Kim, H; Ashton-Miller, JA; De Mott, T; Richardson, JK

    2013-01-01

    Aims Distal symmetric polyneuropathy increases fall risk due to inability to cope with perturbations. We aimed to 1) identify the frontal plane lower limb sensorimotor functions which are necessary for robustness to a discrete, underfoot perturbation during gait; and 2) determine whether changes in the post-perturbed step parameters could distinguish between fallers and non fallers. Methods Forty-two subjects (16 healthy old and 26 with diabetic PN) participated. Frontal plane lower limb sensorimotor functions were determined using established laboratory-based techniques. The subjects' most extreme alterations in step width or step length in response to a perturbation were measured. In addition, falls and fall-related injuries were prospectively recorded. Results Ankle proprioceptive threshold (APrT; p=.025) and hip abduction rate of torque generation (RTG; p=.041) independently predicted extreme step length after medial perturbation, with precise APrT and greater hip RTG allowing maintenance of step length. Fallers demonstrated greater extreme step length changes after medial perturbation than non fallers (percent change = 16.41±8.42 vs 11.0±4.95; p=.06) Conclusions The ability to rapidly generate frontal plane hip strength and/or precisely perceive motion at the ankle is needed to maintain a normal step length after perturbation, a parameter, which distinguishes between fallers and non fallers. PMID:24183899

  14. Telomere length analysis.

    Science.gov (United States)

    Canela, Andrés; Klatt, Peter; Blasco, María A

    2007-01-01

    Most somatic cells of long-lived species undergo telomere shortening throughout life. Critically short telomeres trigger loss of cell viability in tissues, which has been related to alteration of tissue function and loss of regenerative capabilities in aging and aging-related diseases. Hence, telomere length is an important biomarker for aging and can be used in the prognosis of aging diseases. These facts highlight the importance of developing methods for telomere length determination that can be employed to evaluate telomere length during the human aging process. Telomere length quantification methods have improved greatly in accuracy and sensitivity since the development of the conventional telomeric Southern blot. Here, we describe the different methodologies recently developed for telomere length quantification, as well as their potential applications for human aging studies.

  15. Relative leg length is associated with type 2 diabetes differently according to pubertal timing: The Brazilian Longitudinal Study of Adult Health

    Science.gov (United States)

    Mueller, Noel T.; Duncan, Bruce B.; Barreto, Sandhi M.; Chor, Dora; Vigo, Alvaro; Aquino, Estela M. L.; Demerath, Ellen W.; Schmidt, Maria Inês

    2014-01-01

    Objectives Studies from developed societies have shown that individuals with short legs relative to height have higher risk of type 2 diabetes. This has been much less explored in less developed populations where influences on relative leg length and diabetes may differ. The Brazilian Longitudinal Study of Adult Health (in Portuguese, ELSA-Brasil) allows us to test, in a cohort born (1934–1975) and raised when undernutrition was common, whether short legs relative to height is positively associated with diabetes, independent of early-life factors, including birth weight, age at menarche, and young-adult BMI. Methods We used baseline, cross-sectional data from 15,105 participants aged 35–74 years participating in ELSA-Brasil. We created age-and-sex-specific Z scores for leg length index (leg length/height x 100) according to an external reference. Diabetes was defined by self-reported physician diagnosis, medication use, fasting and 2-hour post-75g-load glucose, and A1C. Results A one-unit decrement in leg-length-index Z score was associated with 12% (8–17%) higher prevalence of diabetes in Brazilian adults, after adjustment through Poisson regression for confounders, including race, maternal education, and birth weight. This association persisted after further adjustment for menarche age, BMI (at age 20), buttocks circumference, and waist circumference. It was stronger among women with early menarche (p interaction=0.02). Leg length index was also positively associated with fasting glucose, fasting insulin, 2-hour glucose, and A1C (plegs relative to height is positively associated with diabetes independent of measures of intrauterine growth, pubertal timing, young-adult adiposity. This association is stronger in women with early menarche. PMID:25327531

  16. Temporal and spatial variation in relative abundance and length structure of salmonids in reservoirs: Implications for monitoring

    Science.gov (United States)

    Rhea, D.T.; Hubert, W.A.; Gangl, R.S.; Whaley, R.A.

    2005-01-01

    Spatial and temporal variations in salmonid catch per unit effort (C/f) may affect monitoring efforts in lakes and reservoirs. This study evaluated the spatial and temporal variation in gill-net C/f and length structure of captured salmonids in nearshore (???7.6-m bottom depth) and offshore (>7.6-m bottom depth) areas of two Wyoming reservoirs. Floating experimental gill nets were set as nearshore and offshore pairs at 24 locations in both reservoirs during each of four sampling periods (spring, early summer, late summer, and fall). Salmonid C/f was significantly higher in nearshore areas than in offshore areas during all periods in one reservoir and during all periods except spring in the other reservoir. Mean C/f of rainbow trout Oncorhynchus mykiss was not significantly different between nearshore and offshore areas when water temperatures were 10-13??C in both reservoirs. Length structure of salmonids differed significantly between nearshore and offshore locations and among periods in both reservoirs. These patterns should be considered in both the design and analysis phases of monitoring efforts that use floating experimental gill nets and other sampling gears. ?? Copyright by the American Fisheries Society 2005.

  17. THE EVOLUTION OF BLACK HOLE SCALING RELATIONS IN GALAXY MERGERS

    International Nuclear Information System (INIS)

    Johansson, Peter H.; Burkert, Andreas; Naab, Thorsten

    2009-01-01

    We study the evolution of black holes (BHs) on the M BH -σ and M BH -M bulge planes as a function of time in disk galaxies undergoing mergers. We begin the simulations with the progenitor BH masses being initially below (Δlog M BH,i ∼ -2), on (Δlog M BH,i ∼ 0), and above (Δlog M BH,i ∼ 0.5) the observed local relations. The final relations are rapidly established after the final coalescence of the galaxies and their BHs. Progenitors with low initial gas fractions (f gas = 0.2) starting below the relations evolve onto the relations (Δlog M BH,f ∼ -0.18), progenitors on the relations stay there (Δlog M BH,f ∼ 0), and finally progenitors above the relations evolve toward the relations, but still remain above them (Δlog M BH,f ∼ 0.35). Mergers in which the progenitors have high initial gas fractions (f gas = 0.8) evolve above the relations in all cases (Δlog M BH,f ∼ 0.5). We find that the initial gas fraction is the prime source of scatter in the observed relations, dominating over the scatter arising from the evolutionary stage of the merger remnants. The fact that BHs starting above the relations do not evolve onto the relations indicates that our simulations rule out the scenario in which overmassive BHs evolve onto the relations through gas-rich mergers. By implication our simulations thus disfavor the picture in which supermassive BHs develop significantly before their parent bulges.

  18. A study of damage zones or characteristic lengths as related to the fracture behavior of graphite/epoxy laminates

    Science.gov (United States)

    Yeow, Y. T.; Brinson, H. F.

    1977-01-01

    Uniaxial tensile tests conducted on a variety of graphite/epoxy laminates, containing narrow rectangular slits, square or circular holes with various aspect ratios are discussed. The techniques used to study stable crack or damage zone growth--namely, birefringence coatings, COD gages, and microscopic observations are discussed. Initial and final fracture modes are discussed as well as the effect of notch size and shape, and laminate type on the fracture process. Characteristic lengths are calculated and compared to each other using the point, average and inherent flaw theories. Fracture toughnesses are calculated by the same theories and compared to a boundary integral equation technique. Finite width K-calibration factors are also discussed.

  19. Event-related alpha perturbations related to the scaling of steering wheel corrections.

    Science.gov (United States)

    Brooks, Justin; Kerick, Scott

    2015-10-01

    Previously we derived a new measure relating the driver's steering wheel responses to the vehicle's heading error velocity. This measure, the relative steering wheel compensation (RSWC), changes at times coincident with an alerting stimulus, possibly representing shifts in control strategy as measured by a change in the gain between visual input and motor output. In the present study, we sought to further validate this novel measure by determining the relationship between the RSWC and electroencephalogram (EEG) activity in brain regions associated with sensorimotor transformation processes. These areas have been shown to exhibit event-related spectral perturbation (ERSP) in the alpha frequency band that occurs with the onset of corrective steering wheel maneuvers in response to vehicle perturbations. We hypothesized that these regions would show differential alpha activity depending on whether the RSWC was high or low, reflecting changes in gain between visual input and motor output. Interestingly, we find that low RSWC is associated with significantly less peak desynchronization than larger RSWC. In addition we demonstrate that these differences are not attributable to the amount the steering wheel is turned nor the heading error velocity independently. Collectively these results suggest that neural activity in these sensorimotor regions scales with alertness and may represent differential utilization of multisensory information to control the steering wheel. Published by Elsevier Inc.

  20. Impact of relational coordination on quality of care, postoperative pain and functioning, and length of stay: a nine-hospital study of surgical patients.

    Science.gov (United States)

    Gittell, J H; Fairfield, K M; Bierbaum, B; Head, W; Jackson, R; Kelly, M; Laskin, R; Lipson, S; Siliski, J; Thornhill, T; Zuckerman, J

    2000-08-01

    Health care organizations face pressures from patients to improve the quality of care and clinical outcomes, as well as pressures from managed care to do so more efficiently. Coordination, the management of task interdependencies, is one way that health care organizations have attempted to meet these conflicting demands. The objectives of this study were to introduce the concept of relational coordination and to determine its impact on the quality of care, postoperative pain and functioning, and the length of stay for patients undergoing an elective surgical procedure. Relational coordination comprises frequent, timely, accurate communication, as well as problem-solving, shared goals, shared knowledge, and mutual respect among health care providers. Relational coordination was measured by a cross-sectional questionnaire of health care providers. Quality of care was measured by a cross-sectional postoperative questionnaire of total hip and knee arthroplasty patients. On the same questionnaire, postoperative pain and functioning were measured by the WOMAC osteoarthritis instrument. Length of stay was measured from individual patient hospital records. The subjects for this study were 338 care providers and 878 patients who completed questionnaires from 9 hospitals in Boston, MA, New York, NY, and Dallas, TX, between July and December 1997. Quality of care, postoperative pain and functioning, and length of acute hospital stay. Relational coordination varied significantly between sites, ranging from 3.86 to 4.22 (P <0.001). Quality of care was significantly improved by relational coordination (P <0.001) and each of its dimensions. Postoperative pain was significantly reduced by relational coordination (P = 0.041), whereas postoperative functioning was significantly improved by several dimensions of relational coordination, including the frequency of communication (P = 0.044), the strength of shared goals (P = 0.035), and the degree of mutual respect (P = 0.030) among

  1. Structural validity of a 16-item abridged version of the Cervantes Health-Related Quality of Life scale for menopause: the Cervantes Short-Form Scale.

    Science.gov (United States)

    Coronado, Pluvio J; Borrego, Rafael Sánchez; Palacios, Santiago; Ruiz, Miguel A; Rejas, Javier

    2015-03-01

    The Cervantes Scale is a specific health-related quality of life questionnaire that was originally developed in Spanish to be used in Spain for women through and beyond menopause. It contains 31 items and is time-consuming. The aim of this study was to produce an abridged version with the same dimensional structure and with similar psychometric properties. A representative sample of 516 postmenopausal women (mean [SD] age, 57 [4.31] y) seen in outpatient gynecology clinics and extracted from an observational cross-sectional study was used. Item analysis, internal consistency reliability, item-total and item-dimension correlations, and item correlation with the 12-item Medical Outcomes Study Short Form Health Survey Version 2.0 were studied. Dimensional and full-model confirmatory factor analyses were used to check structure stability. A threefold cross-validation method was used to obtain stable estimates by means of multigroup analysis. The scale was reduced to a 16-item version, the Cervantes Short-Form Scale, containing four main dimensions (Menopause and Health, Psychological, Sexuality, and Couple Relations), with the first dimension composed of three subdimensions (Vasomotor Symptoms, Health, and Aging). Goodness-of-fit statistics were better than those of the extended version (χ(2)/df = 2.493; adjusted goodness-of-fit index, 0.802; parsimony comparative fit index, 0.749; root mean standard error of approximation, 0.054). Internal consistency was good (Cronbach's α = 0.880). Correlations between the extended and the reduced dimensions were high and significant in all cases (P < 0.001; r values ranged from 0.90 for Sexuality to 0.969 for Vasomotor Symptoms). The Cervantes Scale can be reduced to a 16-item abridged version (Cervantes Short-Form Scale) that maintains the original dimensional structure and psychometric properties. At 51% of the original length, this version can be administered faster, making it especially suitable for routine medical practice.

  2. ALGORITHM FOR DYNAMIC SCALING RELATIONAL DATABASE IN CLOUDS

    Directory of Open Access Journals (Sweden)

    Alexander V. Boichenko

    2014-01-01

    Full Text Available This article analyzes the main methods of scalingdatabases (replication, sharding and their supportat the popular relational databases and NoSQLsolutions with different data models: document-oriented, key-value, column-oriented and graph.The article presents an algorithm for the dynamicscaling of a relational database (DB, that takesinto account the specifics of the different types of logic database model. This article was prepared with the support of RFBR (grant № 13-07-00749.

  3. Revisiting Scaling Relations for Giant Radio Halos in Galaxy Clusters

    Science.gov (United States)

    Cassano, R.; Ettori, S.; Brunetti, G.; Giacintucci, S.; Pratt, G. W.; Venturi, T.; Kale, R.; Dolag, K.; Markevitch, Maxim L.

    2013-01-01

    Many galaxy clusters host megaparsec-scale radio halos, generated by ultrarelativistic electrons in the magnetized intracluster medium. Correlations between the synchrotron power of radio halos and the thermal properties of the hosting clusters were established in the last decade, including the connection between the presence of a halo and cluster mergers. The X-ray luminosity and redshift-limited Extended GMRT Radio Halo Survey provides a rich and unique dataset for statistical studies of the halos. We uniformly analyze the radio and X-ray data for the GMRT cluster sample, and use the new Planck Sunyaev-Zel'dovich (SZ) catalog to revisit the correlations between the power of radio halos and the thermal properties of galaxy clusters. We find that the radio power at 1.4 GHz scales with the cluster X-ray (0.1-2.4 keV) luminosity computed within R(sub 500) as P(sub 1.4) approx. L(2.1+/-0.2) - 500). Our bigger and more homogenous sample confirms that the X-ray luminous (L(sub 500) > 5 × 10(exp 44) erg/s)) clusters branch into two populations-radio halos lie on the correlation, while clusters without radio halos have their radio upper limits well below that correlation. This bimodality remains if we excise cool cores from the X-ray luminosities. We also find that P(sub 1.4) scales with the cluster integrated SZ signal within R(sub 500), measured by Planck, as P(sub 1.4) approx. Y(2.05+/-0.28) - 500), in line with previous findings. However, contrary to previous studies that were limited by incompleteness and small sample size, we find that "SZ-luminous" Y(sub 500) > 6×10(exp -5) Mpc(exp 2) clusters show a bimodal behavior for the presence of radio halos, similar to that in the radio-X-ray diagram. Bimodality of both correlations can be traced to clusters dynamics, with radio halos found exclusively in merging clusters. These results confirm the key role of mergers for the origin of giant radio halos, suggesting that they trigger the relativistic particle acceleration.

  4. Oral nutritional supplement use in relation to length of stay in heart failure patients at a regional medical center.

    Science.gov (United States)

    Babb, Ellen B; Rohrer, James

    2017-12-01

    Improving the nutritional status of hospitalized patients has been shown to reduce length of stay (LOS), hospital costs, readmission rates, complication rates, and mortality. Provision of nutrient-rich, liquid, oral nutrition supplements (ONS) is one approach to improve nutritional status. Little information is available on ONS use and LOS among heart failure patients. This study used a retrospective design to examine whether routine ONS use was associated with hospital LOS among 570 heart failure inpatients (89 ONS = yes; 481 ONS = no) at a regional medical center, adjusting for significant personal, locational, and time variables using multiple logistic regression analysis. Oral nutrition supplement use was associated with high LOS in this sample (odds ratio = 2.43). High LOS was also associated with higher Charlson comorbidity index values, discharge destination, hospital room location, and dietitian consults. These results show that ONS orders alone are not adequate to reduce LOS among heart failure patients. Continued research is needed on ways to improve care to reduce LOS among hospitalized patients. © 2017 John Wiley & Sons, Ltd.

  5. Critical Length Criterion and the Arc Chain Model for Calculating the Arcing Time of the Secondary Arc Related to AC Transmission Lines

    International Nuclear Information System (INIS)

    Cong Haoxi; Li Qingmin; Xing Jinyuan; Li Jinsong; Chen Qiang

    2015-01-01

    The prompt extinction of the secondary arc is critical to the single-phase reclosing of AC transmission lines, including half-wavelength power transmission lines. In this paper, a low-voltage physical experimental platform was established and the motion process of the secondary arc was recorded by a high-speed camera. It was found that the arcing time of the secondary arc rendered a close relationship with its arc length. Through the input and output power energy analysis of the secondary arc, a new critical length criterion for the arcing time was proposed. The arc chain model was then adopted to calculate the arcing time with both the traditional and the proposed critical length criteria, and the simulation results were compared with the experimental data. The study showed that the arcing time calculated from the new critical length criterion gave more accurate results, which can provide a reliable criterion in term of arcing time for modeling and simulation of the secondary arc related with power transmission lines. (paper)

  6. Age-related changes in molar topography and shearing crest length in a wild population of mountain Gorillas from Volcanoes National Park, Rwanda.

    Science.gov (United States)

    Glowacka, Halszka; McFarlin, Shannon C; Catlett, Kierstin K; Mudakikwa, Antoine; Bromage, Timothy G; Cranfield, Michael R; Stoinski, Tara S; Schwartz, Gary T

    2016-05-01

    Great ape teeth must remain functional over long lifespans. The molars of the most folivorous apes, the mountain gorillas, must maintain shearing function for 40+ years while the animals consume large quantities of mechanically challenging foods. While other folivorous primates experience dental senescence, which compromises their occlusal surfaces and affects their reproductive success as they age, it is unknown whether dental senescence also occurs in mountain gorillas. In this article, we quantified and evaluated how mountain gorilla molars change throughout their long lifespans. We collected high-resolution replicas of M(1)s (n = 15), M(2)s (n = 13), and M(3)s (n = 11) from a cross-sectional sample of wild mountain gorilla skeletons from the Virunga Volcanoes, ranging in age from 4 to 43 years. We employed dental topographic analyses to track how aspects of occlusal slope, angularity, relief index, and orientation patch count rotated change with age. In addition, we measured the relative length of shearing crests in two- and three-dimensions. Occlusal topography was found to decrease, while 2D relative shearing crest length increased, and 3D relative crest lengths were maintained with age. Our findings indicate that shearing function is maintained throughout the long lifetimes of mountain gorillas. Unlike the dental senescence experienced by other folivorous primates, mountain gorillas do not appear to possess senesced molars despite their long lifetimes, mechanically challenging diets, and decreases in occlusal topography with age. © 2016 Wiley Periodicals, Inc.

  7. Scaling of Primate Forearm Muscle Architecture as It Relates to Locomotion and Posture.

    Science.gov (United States)

    Leischner, Carissa L; Crouch, Michael; Allen, Kari L; Marchi, Damiano; Pastor, Francisco; Hartstone-Rose, Adam

    2018-03-01

    It has been previously proposed that distal humerus morphology may reflect the locomotor pattern and substrate preferred by different primates. However, relationships between these behaviors and the morphological capabilities of muscles originating on these osteological structures have not been fully explored. Here, we present data about forearm muscle architecture in a sample of 44 primate species (N = 55 specimens): 9 strepsirrhines, 15 platyrrhines, and 20 catarrhines. The sample includes all major locomotor and substrate use groups. We isolated each antebrachial muscle and categorized them into functional groups: wrist and digital extensors and flexors, antebrachial mm. that do not cross the wrist, and functional combinations thereof. Muscle mass, physiological cross-sectional area (PCSA), reduced PCSA (RPCSA), and fiber length (FL) are examined in the context of higher taxonomic group, as well as locomotor/postural and substrate preferences. Results show that muscle masses, PCSA, and RPCSA scale with positive allometry while FL scales with isometry indicating that larger primates have relatively stronger, but neither faster nor more flexible, forearms across the sample. When accounting for variation in body size, we found no statistically significant difference in architecture among higher taxonomic groups or locomotor/postural groups. However, we found that arboreal primates have significantly greater FL than terrestrial ones, suggesting that these species are adapted for greater speed and/or flexibility in the trees. These data may affect our interpretation of the mechanisms for variation in humeral morphology and provide information for refining biomechanical models of joint stress and movement in extant and fossil primates. Anat Rec, 301:484-495, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

  8. Galaxy metallicity scaling relations in the EAGLE simulations

    Science.gov (United States)

    De Rossi, María Emilia; Bower, Richard G.; Font, Andreea S.; Schaye, Joop; Theuns, Tom

    2017-12-01

    We quantify the correlations between gas-phase and stellar metallicities and global properties of galaxies, such as stellar mass, halo mass, age and gas fraction, in the Evolution and Assembly of GaLaxies and their Environments suite of cosmological hydrodynamical simulations. The slope of the correlation between stellar mass and metallicity of star-forming (SF) gas (M*-ZSF,gas relation) depends somewhat on resolution, with the higher resolution run reproducing a steeper slope. This simulation predicts a non-zero metallicity evolution, increasing by ≈0.5 dex at ∼109 M⊙ since z = 3. The simulated relation between stellar mass, metallicity and star formation rate at z ≲ 5 agrees remarkably well with the observed fundamental metallicity relation. At M* ≲ 1010.3 M⊙ and fixed stellar mass, higher metallicities are associated with lower specific star formation rates, lower gas fractions and older stellar populations. On the other hand, at higher M*, there is a hint of an inversion of the dependence of metallicity on these parameters. The fundamental parameter that best correlates with the metal content, in the simulations, is the gas fraction. The simulated gas fraction-metallicity relation exhibits small scatter and does not evolve significantly since z = 3. In order to better understand the origin of these correlations, we analyse a set of lower resolution simulations in which feedback parameters are varied. We find that the slope of the simulated M*-ZSF,gas relation is mostly determined by stellar feedback at low stellar masses (M* ≲ 1010 M⊙), and at high masses (M* ≳ 1010 M⊙) by the feedback from active galactic nuclei.

  9. Roles of age, length of service and job in work-related injury: a prospective study of 63,620 person-years in female workers.

    Science.gov (United States)

    Chau, Nearkasen; Dehaene, Dominique; Benamghar, Lahoucine; Bourgkard, Eve; Mur, Jean-Marie; Touron, Christian; Wild, Pascal

    2014-02-01

    The roles of age, length of service and job in various work-related injury types are unknown and deserve investigations among female workers. This study assessed their roles in the occurrence of injury. Three-year prospective study of all 22,952 permanently employed women at the French national railway company: 63,620 person-years, 756 injuries with working days lost, coded using the company's injury classification derived from that of the French health insurance scheme. We investigated the incidence of four types of injury: fall on same level, fall to lower level, materials/equipment/objects handling, and other injuries. Data were analyzed using negative binomial regression. Workers aged workers (45-55 years) were subject to a higher injury risk for fall on same level and fall to lower level. For fall on same level as for fall to lower level the relative risk decreased steadily with increasing length of service with the company, from 1.60 for 1 year to 0.50-0.60 for ≥30 years. For injuries due to materials/equipment/objects handling the relative risk decreased from 1.05 for one year to 0.49 for 5-9 years, and then increased to about 1.50 for 20-29 years and ≥30 years. Younger and shorter lengths of service were at risk for various types of injuries. Higher length of service was at risk for injury due to materials/equipment/objects handling. Preventive measures should consider the respective risks associated with age, years of employment and job. © 2013 Wiley Periodicals, Inc.

  10. Development and Validation of a PTSD-Related Impairment Scale

    Science.gov (United States)

    2012-06-01

    Applications in AIDS, cystic fibrosis , and arthritis. Mtdical Cau, 27, S27-43. Karschnig, H. (2006). How useful is the concept of quality oflife in...discharge, (2) to promote accurate diagnosis , (3) to guide treatment planning by clarifying the domains in which the individual is experiencing...important implica- tions for both the diagnosis and treatment of individuals with PTSD and other stress-related disorders. With respect to diagnosis

  11. Scale dependency of American marten (Martes americana) habitat relations [Chapter 12

    Science.gov (United States)

    Andrew J. Shirk; Tzeidle N. Wasserman; Samuel A. Cushman; Martin G. Raphael

    2012-01-01

    Animals select habitat resources at multiple spatial scales; therefore, explicit attention to scale-dependency when modeling habitat relations is critical to understanding how organisms select habitat in complex landscapes. Models that evaluate habitat variables calculated at a single spatial scale (e.g., patch, home range) fail to account for the effects of...

  12. A scaling law beyond Zipf's law and its relation to Heaps' law

    International Nuclear Information System (INIS)

    Font-Clos, Francesc; Corral, Álvaro; Boleda, Gemma

    2013-01-01

    The dependence on text length of the statistical properties of word occurrences has long been considered a severe limitation on the usefulness of quantitative linguistics. We propose a simple scaling form for the distribution of absolute word frequencies that brings to light the robustness of this distribution as text grows. In this way, the shape of the distribution is always the same, and it is only a scale parameter that increases (linearly) with text length. By analyzing very long novels we show that this behavior holds both for raw, unlemmatized texts and for lemmatized texts. In the latter case, the distribution of frequencies is well approximated by a double power law, maintaining the Zipf's exponent value γ ≃ 2 for large frequencies but yielding a smaller exponent in the low-frequency regime. The growth of the distribution with text length allows us to estimate the size of the vocabulary at each step and to propose a generic alternative to Heaps' law, which turns out to be intimately connected to the distribution of frequencies, thanks to its scaling behavior. (paper)

  13. Measurement of muscle length-related electromyography activity of the hip flexor muscles to determine individual muscle contributions to the hip flexion torque.

    Science.gov (United States)

    Jiroumaru, Takumi; Kurihara, Toshiyuki; Isaka, Tadao

    2014-01-01

    This study aimed to investigate muscle length-related electromyography (EMG) of the iliopsoas (IL) and other hip flexor muscles to determine individual muscle contributions to the hip flexion torque. Ten healthy sedentary young men participated in the EMG experiment. A subgroup of six subjects underwent a magnetic resonance imaging (MRI) measurement to confirm the region of the skin over the IL. Surface EMG signals were sampled from the IL, rectus femoris (RF), sartorius (SA), and tensor fasciae latae (TFL) using an active electrode. The subjects performed maximum voluntary isometric hip flexion with the right hip joint set at -10°, 0°, 30°, and 60°. The root mean square (RMS) value for the TFL at 30° (0.81 ± 0.19, p muscle length changes were significantly correlated in the IL (r =0.39, p muscles.

  14. Relativistic Length Agony Continued

    Science.gov (United States)

    Redzic, D. V.

    2014-06-01

    We made an attempt to remedy recent confusing treatments of some basic relativistic concepts and results. Following the argument presented in an earlier paper (Redzic 2008b), we discussed the misconceptions that are recurrent points in the literature devoted to teaching relativity such as: there is no change in the object in Special Relativity, illusory character of relativistic length contraction, stresses and strains induced by Lorentz contraction, and related issues. We gave several examples of the traps of everyday language that lurk in Special Relativity. To remove a possible conceptual and terminological muddle, we made a distinction between the relativistic length reduction and relativistic FitzGerald-Lorentz contraction, corresponding to a passive and an active aspect of length contraction, respectively; we pointed out that both aspects have fundamental dynamical contents. As an illustration of our considerations, we discussed briefly the Dewan-Beran-Bell spaceship paradox and the 'pole in a barn' paradox.

  15. length-weight relationships, relative condition and sexual cycle of anchovies and sardines of the Tunisian coasts

    OpenAIRE

    Khemiri, S.; Gaamour, A.

    2009-01-01

    La biologie reproductive, la relation taille-masse ainsi que la condition relative de l’anchois Engraulis encrasicolus et de la sardine Sardina pilchardus ont été étudiées le long des régions Nord, Golfe de Tunis, la région Est et la région Sud des côtes tunisiennes durant la période 2000-2002. Pour l’anchois et la sardine, la sex-ratio globale pour toutes les côtes tunisiennes est voisine de 1,0. L’acquisition de la taille de première maturité sexuelle semble être influencée par la tempé...

  16. Psychometric properties of the satisfaction with food-related Life Scale

    DEFF Research Database (Denmark)

    Schnettler, Berta; Miranda, Horacio; Sepúlveda, José

    2013-01-01

    Objective: To evaluate the psychometric properties of the Satisfaction with Food-related Life (SWFL) scale and its relation to the Satisfaction with Life Scale (SWLS) in southern Chile. Methods: A survey was applied to a sample of 316 persons in the principal cities of southern Chile distributed...

  17. Effects of magnetic order on the superconducting length scales and critical fields in single crystal ErNi2B2C

    DEFF Research Database (Denmark)

    Gammel, P.L.; Barber, B.P.; Ramirez, A.P.

    1999-01-01

    The flux line form factor in small angle neutron scattering and transport data determines the superconducting length scares and critical fields in single crystal ErNi2B2C. For H parallel to c, the coherence length xi increases and the penetration depth lambda decreases when crossing T-N = 6.0 K......, the Neel transition. The critical fields show corresponding anomalies near T-N. For H perpendicular to c, the fourfold modulation of the upper critical field H-c2 is strongly temperature dependent, changing sign near T-N, and can be modeled using the anisotropy of the sublattice magnetization....

  18. Reducing the item number to obtain the same-length self-assessment scales: a systematic approach using result of graphical loglinear rasch models

    DEFF Research Database (Denmark)

    Nielsen, Tine; Kreiner, Svend

    2011-01-01

    . For self-assessment, self-scoring and self-interpretational purposes it is deemed prudent that subscales measuring comparable constructs are of the same item length. Consequently, in order to obtain a self-assessment version of the R-D-LSI with an equal number of items in each subscale, a systematic...... approach to item reduction based on results of graphical loglinear Rasch modeling (GLLRM) was designed. This approach was then used to reduce the number of items in the subscales of the R-D-LSI which had an item-length of more than seven items, thereby obtaining the Danish Self-Assessment Learning Styles...

  19. Prediction, postdiction, and perceptual length contraction: a Bayesian low-speed prior captures the cutaneous rabbit and related illusions

    Directory of Open Access Journals (Sweden)

    Daniel eGoldreich

    2013-05-01

    Full Text Available Illusions provide a window into the brain’s perceptual strategies. In certain illusions, an ostensibly task-irrelevant variable influences perception. For example, in touch as in audition and vision, the perceived distance between successive punctate stimuli reflects not only the actual distance but curiously the inter-stimulus time. Stimuli presented at different positions in rapid succession are drawn perceptually towards one another. This effect manifests in several illusions, among them the startling cutaneous rabbit, in which taps delivered to as few as two skin positions appear to hop progressively from one position to the next, landing in the process on intervening areas that were never stimulated. Here we provide an accessible step-by-step exposition of a Bayesian perceptual model that replicates the rabbit and related illusions. The Bayesian observer optimally joins uncertain estimates of spatial location with the expectation that stimuli tend to move slowly. We speculate that this expectation – a Bayesian prior – represents the statistics of naturally occurring stimuli, learned by humans through sensory experience. In its simplest form, the model contains a single free parameter, tau: a time constant for space perception. We show that the Bayesian observer incorporates both pre- and post-dictive inference. Directed spatial attention affects the prediction-postdiction balance, shifting the model’s percept towards the attended location, as observed experimentally in humans. Applying the model to the perception of multi-tap sequences, we show that the low-speed prior fits perception better than an alternative, low-acceleration prior. We discuss the applicability of our model to related tactile, visual, and auditory illusions. To facilitate future model-driven experimental studies, we present a convenient freeware computer program that implements the Bayesian observer; we invite investigators to use this program to create their own

  20. Proximal Region of the Gene Encoding Cytadherence-Related Protein Permits Molecular Typing of Mycoplasma genitalium Clinical Strains by PCR-Restriction Fragment Length Polymorphism

    Science.gov (United States)

    Musatovova, Oxana; Herrera, Caleb; Baseman, Joel B.

    2006-01-01

    Restriction fragment length polymorphism (RFLP) analysis of the PCR-amplified proximal region of the gene encoding cytadherence accessory protein P110 (MG192) revealed DNA sequence divergences among 54 Mycoplasma genitalium clinical strains isolated from the genitourinary tracts of women attending a sexually transmitted disease-related health clinic, plus one from the respiratory tract and one from synovial fluid. Seven of 56 (12.5%) strains exhibited RFLPs following digestion of the proximal region with restriction endonuclease MboI or RsaI, or both. No sequence variability was detected in the distal portion of the gene. PMID:16455921

  1. Scheme-Independent Predictions in QCD: Commensurate Scale Relations and Physical Renormalization Schemes

    International Nuclear Information System (INIS)

    Brodsky, Stanley J.

    1998-01-01

    Commensurate scale relations are perturbative QCD predictions which relate observable to observable at fixed relative scale, such as the ''generalized Crewther relation'', which connects the Bjorken and Gross-Llewellyn Smith deep inelastic scattering sum rules to measurements of the e + e - annihilation cross section. All non-conformal effects are absorbed by fixing the ratio of the respective momentum transfer and energy scales. In the case of fixed-point theories, commensurate scale relations relate both the ratio of couplings and the ratio of scales as the fixed point is approached. The relations between the observables are independent of the choice of intermediate renormalization scheme or other theoretical conventions. Commensurate scale relations also provide an extension of the standard minimal subtraction scheme, which is analytic in the quark masses, has non-ambiguous scale-setting properties, and inherits the physical properties of the effective charge α V (Q 2 ) defined from the heavy quark potential. The application of the analytic scheme to the calculation of quark-mass-dependent QCD corrections to the Z width is also reviewed

  2. EI Scale: an environmental impact assessment scale related to the construction materials used in the reinforced concrete

    Directory of Open Access Journals (Sweden)

    Gilson Morales

    2010-12-01

    Full Text Available This study aimed to create EI Scal, an environmental impact assessment scal, related to construction materials used in the reinforced concrete structure production. The main reason for that was based on the need to classify the environmental impact levels through indicators to assess the damage level process. The scale allowed converting information to estimate the environmental impact caused. Indicators were defined trough the requirements and classification criteria of impact aspects considering the eco-design theory. Moreover, the scale allowed classifying the materials and processes environmental impact through four score categories which resulted in a single final impact score. It was concluded that the EI scale could be cheap, accessible, and relevant tool for environmental impact controlling and reduction, allowing the planning and material specification to minimize the construction negative effects caused in the environment.

  3. Solid renal tumor severity in von Hippel Lindau disease is related to germline deletion length and location.

    Science.gov (United States)

    Maranchie, Jodi K; Afonso, Anoushka; Albert, Paul S; Kalyandrug, Sivaram; Phillips, John L; Zhou, Shubo; Peterson, James; Ghadimi, Bijan M; Hurley, Katheen; Riss, Joseph; Vasselli, James R; Ried, Thomas; Zbar, Berton; Choyke, Peter; Walther, McClellan M; Klausner, Richard D; Linehan, W Marston

    2004-01-01

    von Hippel Lindau disease (VHL) is an autosomal dominant familial cancer syndrome linked to alteration of the VHL tumor suppressor gene. Affected patients are predisposed to develop pheochromocytomas and cystic and solid tumors of the kidney, CNS, pancreas, retina, and epididymis. However, organ involvement varies considerably among families and has been shown to correlate with the underlying germline alteration. Clinically, we observed a paradoxically lower prevalence of renal cell carcinoma (RCC) in patients with complete germline deletion of VHL. To determine if a relationship existed between the type of VHL deletion and disease, we retrospectively evaluated 123 patients from 55 families with large germline VHL deletions, including 42 intragenic partial deletions and 13 complete VHL deletions, by history and radiographic imaging. Each individual and family was scored for cystic or solid involvement of CNS, pancreas, and kidney, and for pheochromocytoma. Germline deletions were mapped using a combination of fluorescent in situ hybridization (FISH) and quantitative Southern and Southern blot analysis. An age-adjusted comparison demonstrated a higher prevalence of RCC in patients with partial germline VHL deletions relative to complete deletions (48.9 vs. 22.6%, p=0.007). This striking phenotypic dichotomy was not seen for cystic renal lesions or for CNS (p=0.22), pancreas (p=0.72), or pheochromocytoma (p=0.34). Deletion mapping revealed that development of RCC had an even greater correlation with retention of HSPC300 (C3orf10), located within the 30-kb region of chromosome 3p, immediately telomeric to VHL (52.3 vs. 18.9%, p <0.001), suggesting the presence of a neighboring gene or genes critical to the development and maintenance of RCC. Careful correlation of genotypic data with objective phenotypic measures will provide further insight into the mechanisms of tumor formation. Copyright 2003 Wiley-Liss, Inc.

  4. EI Scale: an environmental impact assessment scale related to the construction materials used in the reinforced concrete

    OpenAIRE

    Gilson Morales; Antonio Edésio Jungles; Sheila Elisa Scheidemantel Klein; Juliana Guarda

    2010-01-01

    This study aimed to create EI Scal, an environmental impact assessment scal, related to construction materials used in the reinforced concrete structure production. The main reason for that was based on the need to classify the environmental impact levels through indicators to assess the damage level process. The scale allowed converting information to estimate the environmental impact caused. Indicators were defined trough the requirements and classification criteria of impact aspects consid...

  5. Conformal Symmetry as a Template:Commensurate Scale Relations and Physical Renormalization Schemes

    International Nuclear Information System (INIS)

    Brodsky, Stanley J.

    1999-01-01

    Commensurate scale relations are perturbative QCD predictions which relate observable to observable at fixed relative scale, such as the ''generalized Crewther relation'', which connects the Bjorken and Gross-Llewellyn Smith deep inelastic scattering sum rules to measurements of the e + e - annihilation cross section. We show how conformal symmetry provides a template for such QCD predictions, providing relations between observables which are present even in theories which are not scale invariant. All non-conformal effects are absorbed by fixing the ratio of the respective momentum transfer and energy scales. In the case of fixed-point theories, commensurate scale relations relate both the ratio of couplings and the ratio of scales as the fixed point is approached. In the case of the α V scheme defined from heavy quark interactions, virtual corrections due to fermion pairs are analytically incorporated into the Gell-Mann Low function, thus avoiding the problem of explicitly computing and resuming quark mass corrections related to the running of the coupling. Applications to the decay width of the Z boson, the BFKL pomeron, and virtual photon scattering are discussed

  6. Scales

    Science.gov (United States)

    Scales are a visible peeling or flaking of outer skin layers. These layers are called the stratum ... Scales may be caused by dry skin, certain inflammatory skin conditions, or infections. Examples of disorders that ...

  7. Full Length Research Article

    African Journals Online (AJOL)

    Administrator

    Out of the 320 male sheep examined, 87(27.2%) were infected, while 9(19.1%) of the 47 females examined were infected (Table 2). Infection varied from one abattoir to another. Age related distribution of P. cervi is shown in Table 3. Out of 356 adult sheep (>2yrs) examined, 35. Full Length Research Article. 12 ...

  8. Weak Lensing Calibrated M-T Scaling Relation of Galaxy Groups in the COSMOS Field

    NARCIS (Netherlands)

    Kettula, K.; Finoguenov, A.; Massey, R.; Rhodes, J.; Hoekstra, H.; Taylor, J.; Spinelli, P.; Tanaka, M.; Ilbert, O.; Capak, P.; McCracken, H.; Koekemoer, A.

    2013-01-01

    The scaling between X-ray observables and mass for galaxy clusters and groups is instrumental for cluster-based cosmology and an important probe for the thermodynamics of the intracluster gas. We calibrate a scaling relation between the weak lensing mass and X-ray spectroscopic temperature for 10

  9. Suicide-Related Experiences Among Blacks: An Empirical Test of a Suicide Potential Scale

    Science.gov (United States)

    Wenz, Friedrich V.

    1978-01-01

    Developing a Suicide Potential Scale for a number of socially differentiated, stratified census tract populations in a northern city, this paper argues that scores on this scale are related to actual suicidal behavior. These data support the position that variation in suicide among blacks is mainly determined by economic status. (Author)

  10. Myofascial force transmission is increasingly important at lower forces: firing frequency-related length-force characteristics of rat extensor digitorum longus.

    Science.gov (United States)

    Meijer, H J M; Baan, G C; Huijing, P A

    2006-03-01

    Effects of submaximal stimulation frequencies on myofascial force transmission were investigated for rat anterior crural muscles with all motor units activated. Tibialis anterior and extensor hallucis longus (TAEHL) muscles were kept at constant muscle-tendon complex length, but extensor digitorum longus muscle (EDL) was lengthened distally. All muscles were activated simultaneously at 10, 20, 30 and 100 Hz within an intact anterior crural compartment. At lower frequencies, significant proximo-distal EDL force differences exist. Absolute EDL proximo-distal active force differences were highest at 100 Hz (deltaF(dist-prox) = 0.4 N). However, the normalized difference was highest at 10 Hz (deltaF(dist-prox) = 30%F(dist)). Firing-frequency dependent shifts of the ascending limb of the EDL length-force curve to higher lengths were confirmed for a muscle within an intact compartment, although effects of firing frequency assessed at proximal and distal EDL tendons differed quantitatively. As EDL was lengthened distally, TAEHL distal isometric active force decreased progressively. The absolute decrease was highest for 100 Hz (deltaF(from initial) = -0.25 N). However, the highest normalized decrease was found for 10 Hz stimulation (deltaF(from initial) = -40%). At submaximal stimulation frequencies, myofascial force transmission is present and the fraction of force transmitted myofascially increases with progressively lower firing frequencies. Evidently, the stiffness of epimuscular myofascial paths of force transmission decreases less than the stiffness of serial sarcomeres and myotendinous pathways. It is concluded that low firing frequencies as encountered in vivo enhance the relative importance of epimuscular myofascial force transmission with respect to myotendinous force transmission.

  11. How covalence breaks adsorption-energy scaling relations and solvation restores them

    DEFF Research Database (Denmark)

    Vallejo, Federico Calle; Krabbe, Alexander; García Lastra, Juan Maria

    2017-01-01

    of those adsorbates on the metal centers Cr, Mn, Fe, Co, Ni and Cu, using H, F, OH, NH2, CH3, and BH2 as ring ligands. We show that covalence systematically breaks scaling relations under vacuum by strengthening certain M-OOH bonds. However, covalence modifies adsorbate solvation in solution depending...... on the degree of covalence of the metal-adsorbate bonds. The two effects have similar magnitudes and opposite signs, such that scaling relations are restored in solution. Thus, solvation is a crucial ingredient that must be taken into account in studies aimed at breaking scaling relations in solution. Our...... findings suggest that the choice of metal and ligand determines the catalytic activity within the limits imposed by scaling relations, whereas the choice of an appropriate solvent can drive such activity beyond those limits....

  12. 2002 Status of the Armed Forces Survey - Workplace and Gender Relations: Report on Scales and Measures

    National Research Council Canada - National Science Library

    Ormerod, Alayne

    2003-01-01

    ...: Workplace and Gender Relations Survey (2002 WGR). This report describes advances from previous surveys and presents results on scale development as obtained from 19,960 respondents to this survey...

  13. Who is Distressed Applying the Diabetes Related Distress Scale in a Diabetes Clinic

    Science.gov (United States)

    2017-06-09

    59 MDW /SGVU SUBJECT: Professional Presentation Approval 7APR 2017 1. Your paper, entitled Who is Distressed? Applying the Diabetes -Related Distress...Scale in A Diabetes Clinic presented at/published to American Diabetes Association 2017 Meeting, San Francisco, CA (National Conference), 9-16 June...as a publication/presentation, a new 59 MOW Form 3039 must be submitted for review and approval.) Using the Diabetes -Related Distress Scale in

  14. [Development of the Trait Respect-Related Emotions Scale for late adolescence].

    Science.gov (United States)

    Muto, Sera

    2016-02-01

    This study developed a scale to measure the respect-related emotional traits (the Trait Respect-Related Emotions Scale) for late adolescence and examined the reliability and validity. In study 1,368 university students completed the items of the Trait Respect-Related Emotions Scale and other scales of theoretically important personality constructs including adult attachment style, the "Big Five," self-esteem, and two types of narcissistic personality. Factor analysis indicated that there are three factors of trait respect-related emotions: (a) trait (prototypical) respect; (b) trait idolatry (worship and adoration); and (c) trait awe. The three traits associated differentially with the daily experience (frequency) of the five basic respect-related emotions (prototypical respect, idolatry, awe, admiration, and wonder), and other constructs. In Study 2, a test-retest correlation of the new scale with 60 university students indicated good reliability. Both studies generally supported the reliability and validity of the new scale. These findings suggest that, at Ieast in late adolescence, there are large individual differences in respect-related emotion experiences and the trait of respect should be considered as multi-dimensional structure.

  15. An investigation into the variables associated with length of hospital stay related to primary cleft lip and palate surgery and alveolar bone grafting.

    Science.gov (United States)

    Izadi, N; Haers, P E

    2012-10-01

    This retrospective study evaluated variables associated with length of stay (LOS) in hospital for 406 admissions of primary cleft lip and palate and alveolus surgery between January 2007 and April 2009. Three patients were treated as day cases, 343 (84%) stayed one night, 48 (12%) stayed 2 nights and 12 (3%) stayed > 2 nights. Poisson regression analysis showed that there was no association between postoperative LOS and age, distance travelled, diagnosis and type of operation, with a p value > 0.2 for all variables. 60/406 patients stayed 2 nights or more postoperatively mostly due to poor pain control and inadequate oral intake. Patients with palate repair were more likely to have postoperative LOS > 1 night, compared to patients with lip repair, p value = 0.011. Four patients (1%), all of whom had undergone cleft palate surgery, were readmitted within 4 weeks of the operation due to respiratory obstruction or haemorrhage. Using logistic regression, evidence showed that these readmissions were related to a longer original postoperative LOS. This study shows that length of stay for primary cleft lip, palate and alveolus surgery can in most cases be limited to one night postoperatively, provided that adequate support can be provided at home. Copyright © 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  16. Relations between a typical scale and averages in the breaking of fractal distribution

    Science.gov (United States)

    Ishikawa, Atushi; Suzuki, Tadao

    2004-11-01

    We study distributions which have both fractal and non-fractal scale regions by introducing a typical scale into a scale invariant system. As one of models in which distributions follow power law in the large-scale region and deviate further from the power law in the smaller-scale region, we employ 2-dim quantum gravity modified by the R2 term. As examples of distributions in the real world which have similar property to this model, we consider those of personal income in Japan over latest twenty fiscal years. We find relations between the typical scale and several kinds of averages in this model, and observe that these relations are also valid in recent personal income distributions in Japan with sufficient accuracy. We show the existence of the fiscal years so called bubble term in which the gap has arisen in power law, by observing that the data are away from one of these relations. We confirm, therefore, that the distribution of this model has close similarity to those of personal income. In addition, we can estimate the value of Pareto index and whether a big gap exists in power law by using only these relations. As a result, we point out that the typical scale is an useful concept different from average value and that the distribution function derived in this model is an effective tool to investigate these kinds of distributions.

  17. Relating Convective and Microphysical Properties to Large-scale Dynamical and Thermodynamical processes within Tropical Cyclones

    Science.gov (United States)

    Mehta, A. V.; Smith, E. A.; Tripoli, G. J.

    2008-12-01

    It is well known that precipitating convection within tropical cyclones result from a complex interactions among large-scale, storm-scale, cloud-scale, and micro-scale processes. For improved representation of these processes within tropical cyclone models, it is crucial to first understand how micro-scale and cloud- scale properties within tropical cyclones are related to large-scale processes, one of the key objectives of the Year of Tropical Convection (YOTC) program. In this study, a combination of cloud resolving model (CRM) simulations, TRMM Microwave Imager (TMI) measurements, NOAA Optimum Interpolation sea surface temperatures (SST), and Global Forecasting System (GFS) analysis are used to address this issue. The University of Wisconsin Nonhydrostatic Modeling System (UWNMS), a CRM, is used to simulate hurricanes Dennis (9-10 July 2005), Katrina (29-30 2005), and Gustav (30-31 August 2008) at 2-km resolution, nested within 1ºx1º GFS analyses. The UWNMS-generated thermodynamic and hydrometeor profiles are used in a radiative transfer model to calculate brightness temperatures (Tbs) at TMI frequencies. The UWNMS-based Tbs and TRMM-based Tbs are compared to validate overall consistency of the CRM simulations. The cloud-scale profiles of hydrometeors, vertical wind, temperature, and wind shear from UWNMS are analyzed to study their characteristics as functions of SST and GFS-based large-scale regimes represented by parameters including horizontal moisture divergence, vertical moisture flux at 500 hPa, potential vorticity, large-scale wind shear, and Convective Available Potential Energy among others, throughout mature stage of these major hurricanes. Results of this study show how cloud-scale processes are related to large-scale processes within these tropical cyclones.

  18. Large-scale analysis of full-length cDNAs from the tomato (Solanum lycopersicum) cultivar Micro-Tom, a reference system for the Solanaceae genomics.

    Science.gov (United States)

    Aoki, Koh; Yano, Kentaro; Suzuki, Ayako; Kawamura, Shingo; Sakurai, Nozomu; Suda, Kunihiro; Kurabayashi, Atsushi; Suzuki, Tatsuya; Tsugane, Taneaki; Watanabe, Manabu; Ooga, Kazuhide; Torii, Maiko; Narita, Takanori; Shin-I, Tadasu; Kohara, Yuji; Yamamoto, Naoki; Takahashi, Hideki; Watanabe, Yuichiro; Egusa, Mayumi; Kodama, Motoichiro; Ichinose, Yuki; Kikuchi, Mari; Fukushima, Sumire; Okabe, Akiko; Arie, Tsutomu; Sato, Yuko; Yazawa, Katsumi; Satoh, Shinobu; Omura, Toshikazu; Ezura, Hiroshi; Shibata, Daisuke

    2010-03-30

    The Solanaceae family includes several economically important vegetable crops. The tomato (Solanum lycopersicum) is regarded as a model plant of the Solanaceae family. Recently, a number of tomato resources have been developed in parallel with the ongoing tomato genome sequencing project. In particular, a miniature cultivar, Micro-Tom, is regarded as a model system in tomato genomics, and a number of genomics resources in the Micro-Tom-background, such as ESTs and mutagenized lines, have been established by an international alliance. To accelerate the progress in tomato genomics, we developed a collection of fully-sequenced 13,227 Micro-Tom full-length cDNAs. By checking redundant sequences, coding sequences, and chimeric sequences, a set of 11,502 non-redundant full-length cDNAs (nrFLcDNAs) was generated. Analysis of untranslated regions demonstrated that tomato has longer 5'- and 3'-untranslated regions than most other plants but rice. Classification of functions of proteins predicted from the coding sequences demonstrated that nrFLcDNAs covered a broad range of functions. A comparison of nrFLcDNAs with genes of sixteen plants facilitated the identification of tomato genes that are not found in other plants, most of which did not have known protein domains. Mapping of the nrFLcDNAs onto currently available tomato genome sequences facilitated prediction of exon-intron structure. Introns of tomato genes were longer than those of Arabidopsis and rice. According to a comparison of exon sequences between the nrFLcDNAs and the tomato genome sequences, the frequency of nucleotide mismatch in exons between Micro-Tom and the genome-sequencing cultivar (Heinz 1706) was estimated to be 0.061%. The collection of Micro-Tom nrFLcDNAs generated in this study will serve as a valuable genomic tool for plant biologists to bridge the gap between basic and applied studies. The nrFLcDNA sequences will help annotation of the tomato whole-genome sequence and aid in tomato functional

  19. Generation and analysis of a large-scale expressed sequence tags from a full-length enriched cDNA library of Siberian tiger (Panthera tigris altaica).

    Science.gov (United States)

    Guo, Yu; Liu, Changqing; Lu, Taofeng; Liu, Dan; Bai, Chunyu; Li, Xiangchen; Ma, Yuehui; Guan, Weijun

    2014-05-15

    In this study, a full-length enriched cDNA library was successfully constructed from Siberian tiger, the world's most endangered species. The titers of primary and amplified libraries were 1.28×10(6)pfu/mL and 1.59×10(10)pfu/mL respectively. The proportion of recombinants from unamplified library was 91.3% and the average length of exogenous inserts was 1.06kb. A total of 279 individual ESTs with sizes ranging from 316 to 1258bps were then analyzed. Furthermore, 204 unigenes were successfully annotated and involved in 49 functions of the GO classification, cell (175, 85.5%), cellular process (165, 80.9%), and binding (152, 74.5%) are the dominant terms. 198 unigenes were assigned to 156 KEGG pathways, and the pathways with the most representation are metabolic pathways (18, 9.1%). The proportion pattern of each COG subcategory was similar among Panthera tigris altaica, P. tigris tigris and Homo sapiens, and general function prediction only cluster (44, 15.8%) represents the largest group, followed by translation, ribosomal structure and biogenesis (33, 11.8%), replication, recombination and repair (24, 8.6%), and only 7.2% ESTs classified as novel genes. Moreover, the recombinant plasmid pET32a-TAT-COL6A2 was constructed, coded for the Trx-TAT-COL6A2 fusion protein with two 6× His-tags in N and C-terminal. After BCA assay, the concentration of soluble Trx-TAT-COL6A2 recombinant protein was 2.64±0.18mg/mL. This library will provide a useful platform for the functional genome and transcriptome research of for the P. tigris and other felid animals in the future. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. New parametrization for the scale dependent growth function in general relativity

    International Nuclear Information System (INIS)

    Dent, James B.; Dutta, Sourish; Perivolaropoulos, Leandros

    2009-01-01

    We study the scale-dependent evolution of the growth function δ(a,k) of cosmological perturbations in dark energy models based on general relativity. This scale dependence is more prominent on cosmological scales of 100h -1 Mpc or larger. We derive a new scale-dependent parametrization which generalizes the well-known Newtonian approximation result f 0 (a)≡(dlnδ 0 /dlna)=Ω(a) γ (γ=(6/11) for ΛCDM) which is a good approximation on scales less than 50h -1 Mpc. Our generalized parametrization is of the form f(a)=(f 0 (a)/1+ξ(a,k)), where ξ(a,k)=(3H 0 2 Ω 0m )/(ak 2 ). We demonstrate that this parametrization fits the exact result of a full general relativistic evaluation of the growth function up to horizon scales for both ΛCDM and dynamical dark energy. In contrast, the scale independent parametrization does not provide a good fit on scales beyond 5% of the horizon scale (k≅0.01h -1 Mpc).

  1. Reliability of a Scale of Work-Related Self-Efficacy for People with Psychiatric Disabilities

    Science.gov (United States)

    Harris, Meredith

    2010-01-01

    Work-related self-efficacy at a core task level fits with the social cognitive career theory explaining the career development of people with severe mental illness. The aim of this study was to further investigate the psychometric properties of the "Work-related Self- Efficacy Scale" for use with people with psychiatric disabilities. Sixty…

  2. Scale relation in logσ - logε diagrams for Zry-4

    International Nuclear Information System (INIS)

    Cuniberti, A.M.; Picasso, A.C.

    1991-01-01

    The stress relaxation assay allows access to information about plastic behaviour of the corresponding material. This work describes a stress relaxation test carried out on polycrystalline Zry-4 at 293 K to verify the existence of a scale relation related to the plastic state equation. (Author) [es

  3. Peak precipitation intensity in relation to atmospheric conditions and large-scale forcing at midlatitudes

    NARCIS (Netherlands)

    Loriaux, J.M.; Lenderink, Geert; Siebesma, A.P.

    2016-01-01

    Research on relations between atmospheric conditions and extreme precipitation is important to understand and model present-day climate extremes and assess how precipitation extremes might evolve in a future climate. Here we present a statistical analysis of the relation between large-scale

  4. Eysenck Personality Questionnaire scales and paper-and-pencil tests related to creativity.

    Science.gov (United States)

    Schuldberg, David

    2005-08-01

    Pearson correlations for scores on scales of the 1975 version of the Eysenck Personality Questionnaire with measures of schizotypy, hypomania, and creative traits are reported for 625 undergraduates. The Psychoticism scores are correlated .30 with Hypomanic traits, .25 with Perceptual Aberration, and .20 with the How Do You Think, a test of attitudes and activities related to creativity. Extraversion is also related to creativity-relevant scores. Results support a broad and nonspecific role for the Psychoticism scale in relation to both creativity and subclinical symptomatology.

  5. Introducing structural sensitivity into adsorption-energy scaling relations by means of coordination numbers

    Science.gov (United States)

    Calle-Vallejo, Federico; Loffreda, David; Koper, Marc T. M.; Sautet, Philippe

    2015-05-01

    The search for improved heterogeneous catalysts is an important but difficult task. Scaling relations between the adsorption energies of reaction intermediates greatly facilitate the computational design of catalysts. However, this methodology does not currently incorporate structure sensitivity and hence cannot describe adequately the overall activity of realistic catalyst particles and extended surfaces with several facets, edges and apices. Here, we generalize scaling relations by examining twelve different low-index, stepped and kinked surfaces of nine transition metals. This allows us to quantify the effect of the adsorption-site geometry on these relations, ensures a full prediction of their parameters, and helps in identifying intrinsic thermodynamic restrictions to the performance of catalysts. The resulting fully predictable, structure-sensitive scaling relations are a step towards the long-sought rational design of multifaceted catalytic particles. Such a design can now target not only the chemical nature of active materials but also the actual geometry of their active sites.

  6. A reanalysis of five studies on sexual orientation and the relative length of the 2nd and 4th fingers (the 2D:4D ratio).

    Science.gov (United States)

    McFadden, Dennis; Loehlin, John C; Breedlove, S Marc; Lippa, Richard A; Manning, John T; Rahman, Qazi

    2005-06-01

    Five studies have examined the relationship between sexual orientation and the relative lengths of the 2nd and 4th fingers (the 2D:4D ratio). Although differences have commonly been found between heterosexuals and homosexuals, the direction of the difference has not been consistent across studies. The original data from all five studies were reanalyzed in a search for possible explanations of the discrepancies. Because ethnicity is known to affect the 2D:4D ratio, the reanalysis focused on participants who identified themselves as White or Caucasian, the ethnic group that was most numerous in all of the studies. Age differences did not account for the discrepancies. Differences in variability within different groups were minor. One interesting result to emerge from the reanalysis was that the 2D:4D ratios for the homosexual groups were relatively similar across studies. It was the 2D:4D values for the heterosexual participants that varied most, particularly between the USA and the British studies, and these were responsible for many of the discrepancies in the conclusions across studies. The constancy of the 2D:4D ratio for the White homosexuals did not appear to extend to homosexuals of three other ethnicities, and there were also subpopulation differences related to right or left hands.

  7. Relativistic length agony continued

    Directory of Open Access Journals (Sweden)

    Redžić D.V.

    2014-01-01

    Full Text Available We made an attempt to remedy recent confusing treatments of some basic relativistic concepts and results. Following the argument presented in an earlier paper (Redžić 2008b, we discussed the misconceptions that are recurrent points in the literature devoted to teaching relativity such as: there is no change in the object in Special Relativity, illusory character of relativistic length contraction, stresses and strains induced by Lorentz contraction, and related issues. We gave several examples of the traps of everyday language that lurk in Special Relativity. To remove a possible conceptual and terminological muddle, we made a distinction between the relativistic length reduction and relativistic FitzGerald-Lorentz contraction, corresponding to a passive and an active aspect of length contraction, respectively; we pointed out that both aspects have fundamental dynamical contents. As an illustration of our considerations, we discussed briefly the Dewan-Beran-Bell spaceship paradox and the ‘pole in a barn’ paradox. [Projekat Ministarstva nauke Republike Srbije, br. 171028

  8. A low Fermi scale from a simple gaugino-scalar mass relation

    Energy Technology Data Exchange (ETDEWEB)

    Bruemmer, F. [International School for Advanced Studies, Trieste (Italy); Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Buchmueller, W. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-11-15

    In supersymmetric extensions of the Standard Model, the Fermi scale of electroweak symmetry breaking is determined by the pattern of supersymmetry breaking. We present an example, motivated by a higher-dimensional GUT model, where a particular mass relation between the gauginos, third-generation squarks and Higgs fields of the MSSM leads to a Fermi scale smaller than the soft mass scale. This is in agreement with the measured Higgs boson mass. The {mu} parameter is generated independently of supersymmetry breaking, however the {mu} problem becomes less acute due to the little hierarchy between the soft mass scale and the Fermi scale as we argue. The resulting superparticle mass spectra depend on the localization of quark and lepton fields in higher dimensions. In one case, the squarks of the first two generations as well as the gauginos and higgsinos can be in the range of the LHC. Alternatively, only the higgsinos may be accessible at colliders. The lightest superparticle is the gravitino.

  9. Working memory performance inversely predicts spontaneous delta and theta-band scaling relations.

    Science.gov (United States)

    Euler, Matthew J; Wiltshire, Travis J; Niermeyer, Madison A; Butner, Jonathan E

    2016-04-15

    Electrophysiological studies have strongly implicated theta-band activity in human working memory processes. Concurrently, work on spontaneous, non-task-related oscillations has revealed the presence of long-range temporal correlations (LRTCs) within sub-bands of the ongoing EEG, and has begun to demonstrate their functional significance. However, few studies have yet assessed the relation of LRTCs (also called scaling relations) to individual differences in cognitive abilities. The present study addressed the intersection of these two literatures by investigating the relation of narrow-band EEG scaling relations to individual differences in working memory ability, with a particular focus on the theta band. Fifty-four healthy adults completed standardized assessments of working memory and separate recordings of their spontaneous, non-task-related EEG. Scaling relations were quantified in each of the five classical EEG frequency bands via the estimation of the Hurst exponent obtained from detrended fluctuation analysis. A multilevel modeling framework was used to characterize the relation of working memory performance to scaling relations as a function of general scalp location in Cartesian space. Overall, results indicated an inverse relationship between both delta and theta scaling relations and working memory ability, which was most prominent at posterior sensors, and was independent of either spatial or individual variability in band-specific power. These findings add to the growing literature demonstrating the relevance of neural LRTCs for understanding brain functioning, and support a construct- and state-dependent view of their functional implications. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Modeling Nonreactive Molecule-Surface Systems on Experimentally Relevant Time and Length Scales: Dynamics and Conductance of Polyfluorene on Au(111).

    Science.gov (United States)

    Li, Zhi; Tkatchenko, Alexandre; Franco, Ignacio

    2018-03-01

    We propose a computationally efficient strategy to accurately model nonreactive molecule-surface interactions that adapts density functional theory calculations with the Tkatchenko-Scheffler scheme for van der Waals interactions into a simple classical force field. The resulting force field requires just two adjustable parameters per atom type that are needed to capture short-range and polarization interactions. The developed strategy allows for classical molecular dynamics simulation of molecules on surfaces with the accuracy of high-level electronic structure methods but for system sizes (10 3 to 10 7 atoms) and timescales (picoseconds to microseconds) that go well beyond what can be achieved with first-principles methods. Parameters for H, sp 2 C, and O on Au(111) are developed and employed to atomistically model experiments that measure the conductance of a single polyfluorene on Au(111) as a continuous function of its length. The simulations qualitatively capture both the gross and fine features of the observed conductance decay during initial junction elongation and lead to a revised atomistic understanding of the experiment.

  11. Interspecific scaling patterns of talar articular surfaces within primates and their closest living relatives

    Science.gov (United States)

    Yapuncich, Gabriel S; Boyer, Doug M

    2014-01-01

    The articular facets of interosseous joints must transmit forces while maintaining relatively low stresses. To prevent overloading, joints that transmit higher forces should therefore have larger facet areas. The relative contributions of body mass and muscle-induced forces to joint stress are unclear, but generate opposing hypotheses. If mass-induced forces dominate, facet area should scale with positive allometry to body mass. Alternatively, muscle-induced forces should cause facets to scale isometrically with body mass. Within primates, both scaling patterns have been reported for articular surfaces of the femoral and humeral heads, but more distal elements are less well studied. Additionally, examination of complex articular surfaces has largely been limited to linear measurements, so that ‘true area' remains poorly assessed. To re-assess these scaling relationships, we examine the relationship between body size and articular surface areas of the talus. Area measurements were taken from microCT scan-generated surfaces of all talar facets from a comprehensive sample of extant euarchontan taxa (primates, treeshrews, and colugos). Log-transformed data were regressed on literature-derived log-body mass using reduced major axis and phylogenetic least squares regressions. We examine the scaling patterns of muscle mass and physiological cross-sectional area (PCSA) to body mass, as these relationships may complicate each model. Finally, we examine the scaling pattern of hindlimb muscle PCSA to talar articular surface area, a direct test of the effect of mass-induced forces on joint surfaces. Among most groups, there is an overall trend toward positive allometry for articular surfaces. The ectal (= posterior calcaneal) facet scales with positive allometry among all groups except ‘sundatherians', strepsirrhines, galagids, and lorisids. The medial tibial facet scales isometrically among all groups except lemuroids. Scaling coefficients are not correlated with sample

  12. Full-length coding sequences of three major histocompatibility complex class I-related chain A alleles, MICA*019, MICA*027 and MICA*045, identified by sequence-based typing in Chinese individuals.

    Science.gov (United States)

    Xu, Y P; Gao, S Q; Tao, H

    2015-10-01

    Full-length coding sequences of three major histocompatibility complex class I-related chain A alleles, MICA*019, MICA*027 and MICA*045. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Validity and reliability of the tuberculosis-related stigma scale version for Brazilian Portuguese.

    Science.gov (United States)

    de Almeida Crispim, Juliane; da Silva, Laís Mara Caetano; Yamamura, Mellina; Popolin, Marcela Paschoal; Ramos, Antônio Carlos Vieira; Arroyo, Luiz Henrique; de Queiroz, Ana Angélica Rêgo; de Souza Belchior, Aylana; Dos Santos, Danielle Talita; Pieri, Flávia Meneguetti; Rodrigues, Ludmila Barbosa Bandeira; Protti, Simone Terezinha; Pinto, Ione Carvalho; Palha, Pedro Fredemir; Arcêncio, Ricardo Alexandre

    2017-07-21

    Stigma associated with tuberculosis (TB) has been an object of interest in several regions of the world. The behaviour presented by patients as a result of social discrimination has contributed to delays in diagnosis and the abandonment of treatment, leading to an increase in the cases of TB and drug resistance. The identification of populations affected by stigma and its measurement can be assessed with the use of valid and reliable instruments developed or adapted to the target culture. This aim of this study was to analyse the initial psychometric properties of the Tuberculosis-Related Stigma scale in Brazil, for TB patients. The Tuberculosis-Related Stigma scale is a specific scale for measuring stigma associated with TB, originally validated in Thailand. It presents two dimensions to be assessed, namely Community perspectives toward tuberculosis and Patient perspectives toward tuberculosis. The first has 11 items regarding the behaviour of the community in relation to TB, and the second is made up of 12 items related to feelings such as fear, guilt and sorrow in coping with the disease. A pilot test was conducted with 83 TB patients, in order to obtain the initial psychometric properties of the scale in the Brazilian Portuguese version, enabling simulation of the field study. As regards its psychometric properties, the scale presented acceptable internal consistency for its dimensions, with values ≥0.70, the absence of floor and ceiling effects, which is favourable for the property of scale responsiveness, satisfactory converging validity for both dimensions, with values over 0.30 for initial studies, and diverging validity, with adjustment values different from 100%. The results found show that the Tuberculosis-Related Stigma scale can be a valid and reliable instrument for the Brazilian context.

  14. Psychometric evaluation of revised Task-Related Worry Scale (TRWS-R: A Mokken model analysis

    Directory of Open Access Journals (Sweden)

    Martin Marko

    2016-01-01

    Full Text Available Task-related worries can be understood as an inherent component of an anxious state and stress response. Under evaluating conditions (e.g. cognitive testing, these worries, due to cognitive interference they create, may have undesirable effects on a cognitive performance at hand. Since cognitive interference has been documented to affect a broad spectrum of cognitive performance (Hembree, 1988, development of a method for its assessment is required. For this purpose we modified a part of the original Cognitive Interference Questionnaire (Sarason et al., 1986 in order to create the revised Task- Related Worry Scale (TRWS-R and investigated its psychometric properties. Data from two hundreds of participants (72 male, 139 female; age ranging from 18 to 24 were obtained to inspect the modified scale’s properties on Slovak sample. After the scale was reformulated and shortened, the resulting set of eight items was subjected for examination of internal consistency (Cronbach'salpha, Revelle’sbeta, Armor'stheta, and McDonald'somega coefficients, expected unidimensionality (confirmatory factor analysis, and scalability (nonparametric item response model - Mokken scale analysis. The results indicate that the scale has rather reasonable consistency. Both mean inter-item correlation and corrected mean item-score correlation were relatively high (r= .469 and r = .636 respectively. Additionally, all estimated consistency coefficients reached required thresholds (namely: ? = .88,ß = .79,? = .86,? =.88. Robust confirmatory factor analysis and Cronbach-Mesbah curve convergently supported the hypothesized unidimensional factor solution (CFA fit indexes: ?2 (28= 26.73, p = .143, CFI = .994, TLI = .992, RMSEA = .041, SRMR = .055.. Moreover, Mokken scale analysis indicated that the scale is scalable (scale’s H = .496 and satisfies the criteria of both monotone homogenity model and double monotonicity model (no significant violations were present. Consistency

  15. Residual stress determination in oxide layers at different length scales combining Raman spectroscopy and X-ray diffraction: Application to chromia-forming metallic alloys

    Science.gov (United States)

    Guerain, Mathieu; Grosseau-Poussard, Jean-Luc; Geandier, Guillaume; Panicaud, Benoit; Tamura, Nobumichi; Kunz, Martin; Dejoie, Catherine; Micha, Jean-Sebastien; Thiaudière, Dominique; Goudeau, Philippe

    2017-11-01

    In oxidizing environments, the protection of metals and alloys against further oxidation at high temperature is provided by the oxide film itself. This protection is efficient only if the formed film adheres well to the metal (substrate), i.e., without microcracks and spalls induced by thermomechanical stresses. In this study, the residual stresses at both macroscopic and microscopic scales in the oxide film adhering to the substrate and over the damaged areas have been rigorously determined on the same samples for both techniques. Ni-30Cr and Fe-47Cr alloys have been oxidized together at 900 and 1000 °C, respectively, to create films with a thickness of a few microns. A multi-scale approach was adopted: macroscopic stress was determined by conventional X-ray diffraction and Raman spectroscopy, while microscopic residual stress mappings were performed over different types of bucklings using Raman micro-spectroscopy and synchrotron micro-diffraction. A very good agreement is found at macro- and microscales between the residual stress values obtained with both techniques, giving confidence on the reliability of the measurements. In addition, relevant structural information at the interface between the metallic substrate and the oxide layer was collected by micro-diffraction, a non-destructive technique that allows mapping through the oxide layer, and both the grain size and the crystallographic orientation of the supporting polycrystalline metal located either under a buckling or not were measured.

  16. Psychological effects of relational job characteristics: validation of the scale for hospital nurses.

    Science.gov (United States)

    Santos, Alda; Castanheira, Filipa; Chambel, Maria José; Amarante, Michael Vieira; Costa, Carlos

    2017-07-01

    This study validates the Portuguese version of the psychological effects of the relational job characteristics scale among hospital nurses in Portugal and Brazil. Increasing attention has been given to the social dimension of work, following the transition to a service economy. Nevertheless, and despite the unquestionable relational characteristics of nursing work, scarce research has been developed among nurses under a relational job design framework. Moreover, it is important to develop instruments that study the effects of relational job characteristics among nurses. We followed Messick's framework for scale validation, comprising the steps regarding the response process and internal structure, as well as relationships with other variables (work engagement and burnout). Statistical analysis included exploratory factor analysis and confirmatory factor analysis. The psychological effects of the relational job characteristics scale provided evidence of good psychometric properties with Portuguese and Brazilian hospital nurses. Also, the psychological effects of the relational job characteristics are associated with nurses' work-related well-being: positively with work engagement and negatively concerning burnout. Hospitals that foster the relational characteristics of nursing work are contributing to their nurses' work-related well-being, which may be reflected in the quality of care and patient safety. © 2017 John Wiley & Sons Ltd.

  17. High-Resolution Amplified Fragment Length Polymorphism Typing of Lactococcus lactis Strains Enables Identification of Genetic Markers for Subspecies-Related Phenotypes▿

    Science.gov (United States)

    Kütahya, Oylum Erkus; Starrenburg, Marjo J. C.; Rademaker, Jan L. W.; Klaassen, Corné H. W.; van Hylckama Vlieg, Johan E. T.; Smid, Eddy J.; Kleerebezem, Michiel

    2011-01-01

    A high-resolution amplified fragment length polymorphism (AFLP) methodology was developed to achieve the delineation of closely related Lactococcus lactis strains. The differentiation depth of 24 enzyme-primer-nucleotide combinations was experimentally evaluated to maximize the number of polymorphisms. The resolution depth was confirmed by performing diversity analysis on 82 L. lactis strains, including both closely and distantly related strains with dairy and nondairy origins. Strains clustered into two main genomic lineages of L. lactis subsp. lactis and L. lactis subsp. cremoris type-strain-like genotypes and a third novel genomic lineage rooted from the L. lactis subsp. lactis genomic lineage. Cluster differentiation was highly correlated with small-subunit rRNA homology and multilocus sequence analysis (MLSA) studies. Additionally, the selected enzyme-primer combination generated L. lactis subsp. cremoris phenotype-specific fragments irrespective of the genotype. These phenotype-specific markers allowed the differentiation of L. lactis subsp. lactis phenotype from L. lactis subsp. cremoris phenotype strains within the same L. lactis subsp. cremoris type-strain-like genomic lineage, illustrating the potential of AFLP for the generation of phenotype-linked genetic markers. PMID:21666014

  18. Scaling relation between earthquake magnitude and the departure time from P wave similar growth

    Science.gov (United States)

    Noda, Shunta; Ellsworth, William L.

    2016-01-01

    We introduce a new scaling relation between earthquake magnitude (M) and a characteristic of initial P wave displacement. By examining Japanese K-NET data averaged in bins partitioned by Mw and hypocentral distance, we demonstrate that the P wave displacement briefly displays similar growth at the onset of rupture and that the departure time (Tdp), which is defined as the time of departure from similarity of the absolute displacement after applying a band-pass filter, correlates with the final M in a range of 4.5 ≤ Mw ≤ 7. The scaling relation between Mw and Tdp implies that useful information on the final M can be derived while the event is still in progress because Tdp occurs before the completion of rupture. We conclude that the scaling relation is important not only for earthquake early warning but also for the source physics of earthquakes.

  19. The MMPI-2 Clinical Scales and Restructured Clinical (RC) Scales: comparative psychometric properties and relative diagnostic efficiency in young adults.

    Science.gov (United States)

    Osberg, Timothy M; Haseley, Erin N; Kamas, Michele M

    2008-01-01

    We examined the psychometric properties of the Restructured Clinical (RC) scales (Tellegen et al., 2003) of the MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) in a large sample (N = 744) of 18-year-old college freshman. We found that the RC scales demonstrated good convergence with their Clinical scale counterparts and were more distinctive than the Clinical scales. The patterns of discriminant correlations for the RC scales were slightly clearer than those of the Clinical scales and a set of other existing MMPI-2 scales. Diagnostic efficiency statistics based on Clinical and RC scale elevation status did not differ appreciably. However, the diagnostic efficiency statistics of cutoff scores derived from mean RC and Clinical scale T scores improved on the traditional scale elevation measures. We consider the clinical implications of these findings.

  20. Determining relative bulk viscosity of kilometre-scale crustal units using field observations and numerical modelling

    Science.gov (United States)

    Gardner, Robyn L.; Piazolo, Sandra; Daczko, Nathan R.

    2017-11-01

    Though the rheology of kilometre-scale polymineralic rock units is crucial for reliable large-scale, geotectonic models, this information is difficult to obtain. In geotectonic models, a layer is defined as an entity at the kilometre scale, even though it is heterogeneous at the millimetre to metre scale. Here, we use the shape characteristics of the boundaries between rock units to derive the relative bulk viscosity of those units at the kilometre scale. We examine the shape of a vertically oriented ultramafic, harzburgitic-lherzolitic unit, which developed a kilometre-scale pinch and swell structure at mid-crustal conditions ( 600 °C, 8.5 kbar), in the Anita Shear Zone, New Zealand. The ultramafic layer is embedded between a typical polymineralic paragneiss to the west, and a feldspar-quartz-hornblende orthogneiss, to the east. Notably, the boundaries on either side of the ultramafic layer give the ultramafics an asymmetric shape. Microstructural analysis shows that deformation was dominated by dislocation creep (n = 3). Based on the inferred rheological behaviour from the field, a series of numerical simulations are performed. Relative and absolute values are derived for bulk viscosity of the rock units by comparing boundary tortuosity difference measured on the field example and the numerical series. Our analysis shows that during deformation at mid-crustal conditions, paragneisses can be 30 times less viscous than an ultramafic unit, whereas orthogneisses have intermediate viscosity, 3 times greater than the paragneisses. If we assume a strain rate of 10- 14 s- 1 the ultramafic, orthogneiss and paragneiss have syn-deformational viscosities of 3 × 1022, 2.3 × 1021 and 9.4 × 1020 Pa s, respectively. Our study shows pinch and swell structures are useful as a gauge to assess relative bulk viscosity of rock units based on shape characteristics at the kilometre scale and in non-Newtonian flow regimes, even where heterogeneity occurs within the units at the

  1. Longitudinal multigroup invariance analysis of the satisfaction with food-related life scale in university students

    DEFF Research Database (Denmark)

    Schnettler, Berta; Miranda, Horacio; Miranda-Zapata, Edgardo

    2017-01-01

    This study examined longitudinal measurement invariance in the Satisfaction with Food-related Life (SWFL) scale using follow-up data from university students. We examined this measure of the SWFL in different groups of students, separated by various characteristics. Through non...... in this research. It is also possible to suggest that satisfaction with food-related life is associated with sex and age....... students of both sexes, and among those older and younger than 22 years. Generally, these findings suggest that the SWFL scale has satisfactory psychometric properties for longitudinal measurement invariance in university students with similar characteristics as the students that participated...

  2. Tapasin facilitation of natural HLA-A and -B allomorphs is strongly influenced by peptide length, depends on stability, and separates closely related allomorphs

    DEFF Research Database (Denmark)

    Geironson, Linda; Thuring, Camilla; Harndahl, Mikkel

    2013-01-01

    Despite an abundance of peptides inside a cell, only a small fraction is ultimately presented by HLA-I on the cell surface. The presented peptides have HLA-I allomorph-specific motifs and are restricted in length. So far, detailed length studies have been limited to few allomorphs. Peptide-HLA-I ...

  3. 7 Length-weight relationship

    African Journals Online (AJOL)

    Administrator

    Length-weight measurements were taken from well-preserved fish specimens from which stomachs were extracted for the analysis of the food contents, using frequency of occurrence, numerical and gravimetric methods, as well as index of relative importance. The length-frequency analysis showed a size distribution with a ...

  4. Pion nucleus scattering lengths

    International Nuclear Information System (INIS)

    Huang, W.T.; Levinson, C.A.; Banerjee, M.K.

    1971-09-01

    Soft pion theory and the Fubini-Furlan mass dispersion relations have been used to analyze the pion nucleon scattering lengths and obtain a value for the sigma commutator term. With this value and using the same principles, scattering lengths have been predicted for nuclei with mass number ranging from 6 to 23. Agreement with experiment is very good. For those who believe in the Gell-Mann-Levy sigma model, the evaluation of the commutator yields the value 0.26(m/sub σ//m/sub π/) 2 for the sigma nucleon coupling constant. The large dispersive corrections for the isosymmetric case implies that the basic idea behind many of the soft pion calculations, namely, slow variation of matrix elements from the soft pion limit to the physical pion mass, is not correct. 11 refs., 1 fig., 3 tabs

  5. OBSERVED SCALING RELATIONS FOR STRONG LENSING CLUSTERS: CONSEQUENCES FOR COSMOLOGY AND CLUSTER ASSEMBLY

    International Nuclear Information System (INIS)

    Comerford, Julia M.; Moustakas, Leonidas A.; Natarajan, Priyamvada

    2010-01-01

    Scaling relations of observed galaxy cluster properties are useful tools for constraining cosmological parameters as well as cluster formation histories. One of the key cosmological parameters, σ 8 , is constrained using observed clusters of galaxies, although current estimates of σ 8 from the scaling relations of dynamically relaxed galaxy clusters are limited by the large scatter in the observed cluster mass-temperature (M-T) relation. With a sample of eight strong lensing clusters at 0.3 8 , but combining the cluster concentration-mass relation with the M-T relation enables the inclusion of unrelaxed clusters as well. Thus, the resultant gains in the accuracy of σ 8 measurements from clusters are twofold: the errors on σ 8 are reduced and the cluster sample size is increased. Therefore, the statistics on σ 8 determination from clusters are greatly improved by the inclusion of unrelaxed clusters. Exploring cluster scaling relations further, we find that the correlation between brightest cluster galaxy (BCG) luminosity and cluster mass offers insight into the assembly histories of clusters. We find preliminary evidence for a steeper BCG luminosity-cluster mass relation for strong lensing clusters than the general cluster population, hinting that strong lensing clusters may have had more active merging histories.

  6. Large scale inference in the Infinite Relational Model: Gibbs sampling is not enough

    DEFF Research Database (Denmark)

    Albers, Kristoffer Jon; Moth, Andreas Leon Aagard; Mørup, Morten

    2013-01-01

    The stochastic block-model and its non-parametric extension, the Infinite Relational Model (IRM), have become key tools for discovering group-structure in complex networks. Identifying these groups is a combinatorial inference problem which is usually solved by Gibbs sampling. However, whether...... Gibbs sampling suffices and can be scaled to the modeling of large scale real world complex networks has not been examined sufficiently. In this paper we evaluate the performance and mixing ability of Gibbs sampling in the Infinite Relational Model (IRM) by implementing a high performance Gibbs sampler....... We find that Gibbs sampling can be computationally scaled to handle millions of nodes and billions of links. Investigating the behavior of the Gibbs sampler for different sizes of networks we find that the mixing ability decreases drastically with the network size, clearly indicating a need...

  7. Positive Relational Management for healthy organizations: psychometric properties of a new scale for prevention for workers

    Directory of Open Access Journals (Sweden)

    Annamaria Di Fabio

    2016-10-01

    Full Text Available This contribution aims at evaluating the psychometric properties of the Positive Relational Management Scale (PRMS in a sample of two hundred and fifty-one Italian workers. The dimensionality, reliability, and concurrent validity of the scale were investigated. Confirmatory factor analysis supported a correlated three-dimensional version of the scale, comprising Respect, Caring, and Connectedness. Latent correlations among the dimensions were moderate-to-strong (.44 - .57, but suggestive of the multidimensionality of the scores. In addition, good internal consistency was confirmed. The concurrent validity is good as the Pearson’s correlations between PRMS and measure for social support, life satisfaction, life meaningfulness, and flourishing range from .39 to .52. The results indicate that the PRMS is a valid instrument for measuring positive relational management at work in the Italian context within a positive preventive perspective.

  8. Positive Relational Management for Healthy Organizations: Psychometric Properties of a New Scale for Prevention for Workers.

    Science.gov (United States)

    Di Fabio, Annamaria

    2016-01-01

    This contribution aims at evaluating the psychometric properties of the Positive Relational Management Scale (PRMS) in a sample of 251 Italian workers. The dimensionality, reliability, and concurrent validity of the scale were investigated. Confirmatory factor analysis supported a correlated three-dimensional version of the scale, comprising Respect, Caring, and Connectedness. Latent correlations among the dimensions were moderate-to-strong (0.44-0.57), but suggestive of the multidimensionality of the scores. In addition, good internal consistency was confirmed. The concurrent validity is good as the Pearson's correlations between PRMS and measure for social support, life satisfaction, life meaningfulness, and flourishing range from 0.39 to 0.52. The results indicate that the PRMS is a valid instrument for measuring positive relational management at work in the Italian context within a positive preventive perspective.

  9. Enhancement of scale-related sensitivity through field-work prototyping and materializations

    Directory of Open Access Journals (Sweden)

    Tadeja Zupančič

    2013-07-01

    Full Text Available This article addresses the problems related to the student lacking of the comprehension of the space and proportions scale in architectural and urban design education. The research is based on carefully selected case studies taken from our recent architectural-urban design workshops, which have presented a methodological framework process within the design ideas have been tested by the complex process of physical materialization. Our goal have been to develop the adequate methodological model which would enhance the scale-related sensitivity of students through field-work prototyping and materialization »in one to one scale«. The discussion covers some potentials and limitations of the model proposed and focuses to the potentials of the scientific research level in the implementation of the practice-based research in architecture and urban design.

  10. Combination of Complement-Dependent Cytotoxicity and Relative Fluorescent Quantification of HLA Length Polymorphisms Facilitates the Detection of a Loss of Heterozygosity

    Directory of Open Access Journals (Sweden)

    Klaus Witter

    2014-01-01

    Full Text Available Loss of heterozygosity (LOH is a common event in malignant cells. In this work we introduce a new approach to identify patients with loss of heterozygosity in the HLA region either at first diagnosis or after HLA mismatched allogeneic HSCT. Diagnosis of LOH requires a high purity of recipient target cells. FACS is time consuming and also frequently prevented by rather nonspecific or unknown immune phenotype. The approach for recipient cell enrichment is based on HLA targeted complement-dependent cytotoxicity (CDC. Relative fluorescent quantification (RFQ analysis of HLA intron length polymorphisms then allows analysis of HLA heterozygosity. The approach is exemplified in recent clinical cases illustrating the detection of an acquired allele loss. As illustrated in one case with DPB1, distinct HLA loci in donor and patient were sufficient for both proof of donor cell removal and evaluation of allele loss in the patient's leukemic cells. Results were confirmed using HLA-B RFQ analysis and leukemia-associated aberrant immunophenotype (LAIP based cell sort. Both results confirmed suspected loss of HLA heterozygosity. Our approach complements or substitutes for FACS-based cell enrichment; hence it may be further developed as novel routine diagnostic tool. This allows rapid recipient cell purification and testing for loss of HLA heterozygosity before and after allogeneic HSCT in easily accessible peripheral blood samples.

  11. A study of the drift function and relative scale factors based on two juxtaposed CG5 relative gravimeters.

    Science.gov (United States)

    Nielsen, Jens Emil; Strykowski, Gabriel

    2014-05-01

    A time-wise drift of one standard relative gravimeter can be modelled by linking the measurements of a gravity survey to high accuracy gravity stations with known gravity values. Alternatively, the measurements can be performed in one station with not necessarily known, but a constant gravity value. In both cases, and prior to drift function estimation, the gravity measurements should be corrected for systematics caused by the tidal accelerations. Typically the time-wise drift is modelled by a linear function. For Scintrex CG5 this linear drift is particularly strong and significant. We have performed long time series measurements (weeks and months) using two juxtaposed CG5 instruments on our new absolute gravity station at the Technical University of Denmark. The instruments are only few decimetres apart, so it is reasonable to assume that the true tidal acceleration on both gravimeters is the same. However, the signature of the tidal components is in principle scaled by a scaling factor for each gravimeter relating the differences in the counter reading values to the gravity differences in mGals. For Scintrex CG5 this scaling factor is close to one. Knowing the position of our gravimeters the available tidal model yields a time-wise signature of the tidal accelerations on both gravimeters. The above setup can be used to decompose the gravity measurements into the following constituencies: • The tidal signal • The relative scale factor between the two gravimeters • The individual drift function for each gravimeter • The noise Concerning the individual drift function for each gravimeter it is only for short time windows that it can be regarded linear. For wider time windows there is a significant 2nd order component of the drift function. In our poster we will discuss the above decomposition and study the appropriate drift model for different widths of the time-window and its stability in time.

  12. Renormalization group and relations between scattering amplitudes in a theory with different mass scales

    International Nuclear Information System (INIS)

    Gulov, A.V.; Skalozub, V.V.

    2000-01-01

    In the Yukawa model with two different mass scales the renormalization group equation is used to obtain relations between scattering amplitudes at low energies. Considering fermion-fermion scattering as an example, a basic one-loop renormalization group relation is derived which gives possibility to reduce the problem to the scattering of light particles on the external field substituting a heavy virtual state. Applications of the results to problem of searching new physics beyond the Standard Model are discussed [ru

  13. German National Proficiency Scales in Biology: Internal Structure, Relations to General Cognitive Abilities and Verbal Skills

    Science.gov (United States)

    Kampa, Nele; Köller, Olaf

    2016-01-01

    National and international large-scale assessments (LSA) have a major impact on educational systems, which raises fundamental questions about the validity of the measures regarding their internal structure and their relations to relevant covariates. Given its importance, research on the validity of instruments specifically developed for LSA is…

  14. Relations between coordinate and potential scaling in the high-density limit

    Science.gov (United States)

    Whittingham, Takeyce K.; Burke, Kieron

    2005-04-01

    Exact relations are derived between scaling to the high-density limit of density functional theory and taking Z to infinity for nondegenerate atoms. Görling-Levy perturbation results are deduced for hydrogenic densities. The kinetic contribution to the correlation energy is also studied, and estimates given for its value for neutral atoms. Popular approximate functionals are tested against these benchmarks.

  15. Galactic bulges from Hubble Space Telescope NICMOS observations : Global scaling relations

    NARCIS (Netherlands)

    Balcells, Marc; Graham, Alister W.; Peletier, Reynier F.

    2007-01-01

    We investigate bulge and disk scaling relations using a volume-corrected sample of early-to intermediate-type disk galaxies in which, importantly, the biasing flux from additional nuclear components has been modeled and removed. Structural parameters are obtained from a seeing-convolved, bulge +

  16. The Work-Related Quality of Life Scale for Higher Education Employees

    Science.gov (United States)

    Edwards, Julian A.; Van Laar, Darren; Easton, Simon; Kinman, Gail

    2009-01-01

    Previous research suggests that higher education employees experience comparatively high levels of job stress. A range of instruments, both generic and job-specific, has been used to measure stressors and strains in this occupational context. The Work-related Quality of Life (WRQoL) scale is a measure designed to capture perceptions of the working…

  17. Critical exponents and scaling relations for self-organized critical phenomena

    Science.gov (United States)

    Tang, Chao; Bak, Per

    1988-01-01

    Critical indices beta, gamma delta, nv, etc. are defined and calculated for self-organized critical phenomena. Scaling relations are derived and checked numerically. The order-parameter exponent beta describes the spontaneous current and the relaxation to the criticl point. The power spectrum has 'l/f' behavior with the exponent phi = nv x z, where z is the dynamical critical exponent.

  18. Constraints on Dark Energy, Observable-mass Scaling Relations, Neutrino Properties and Gravity from Galaxy Clusters

    DEFF Research Database (Denmark)

    Rapetti Serra, David Angelo

    Using a data set of 238 cluster detections drawn from the ROSAT All-Sky Survey and X-ray follow-up observations from the Chandra X-ray Observatory and/or ROSAT for 94 of those clusters we obtain tight constraints on dark energy, both luminosity-mass and temperature-mass scaling relations, neutrin...

  19. The spatial extent of rainfall events and its relation to precipitation scaling

    NARCIS (Netherlands)

    Lochbihler, K.U.; Lenderink, Geert; Siebesma, A.P.

    2017-01-01

    Observations show that subdaily precipitation extremes increase with dew point temperature at a rate exceeding the Clausius-Clapeyron (CC) relation. The understanding of this so-called super CC scaling is still incomplete, and observations of convective cell properties could provide important

  20. The crystal structure of full-length Sizzled from Xenopus laevis yields insights into Wnt-antagonistic function of secreted Frizzled-related proteins.

    Science.gov (United States)

    Bu, Qixin; Li, Zhiqiang; Zhang, Junying; Xu, Fei; Liu, Jianmei; Liu, Heli

    2017-09-29

    The Wnt-signaling pathway is crucial to cell proliferation, differentiation, and migration. The secreted Frizzled-related proteins (sFRPs) represent the largest family of secreted Wnt inhibitors. However, their function in antagonizing Wnt signaling has remained somewhat controversial. Here, we report the crystal structure of Sizzled from Xenopus laevis , the first full-length structure of an sFRP. Tethered by an inter-domain disulfide bond and a linker, the N-terminal cysteine-rich domain (CRD) and the C-terminal netrin-like domain (NTR) of Sizzled are arranged in a tandem fashion, with the NTR domain occluding the groove of CRD for Wnt accessibility. A Dual-Luciferase assay demonstrated that removing the NTR domain and replacing the CRD groove residues His-116 and His-118 with aromatic residues may significantly enhance antagonistic function of Sizzled in inhibiting Wnt3A signaling. Sizzled is a monomer in solution, and Sizzled CRD exhibited different packing in the crystal, suggesting that sFRPs do not have a conserved CRD dimerization mode. Distinct from the canonical NTR domain, the Sizzled NTR adopts a novel α/β folding with two perpendicular helices facing the central mixed β-sheet. The subgroup of human sFRP1/2/5 and Sizzled should have a similar NTR domain that features a highly positively charged region, opposite the NTR-CRD interface, suggesting that the NTR domain in human sFRPs, at least sFRP1/2/5, is unlikely to bind to Wnt but is likely involved in biphasic Wnt signaling modulation. In summary, the Sizzled structure provides the first insights into how the CRD and the NTR domains relate to each other for modulating Wnt-antagonistic function of sFRPs. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  1. NGC 1275: An Outlier of the Black Hole-Host Scaling Relations

    Directory of Open Access Journals (Sweden)

    Eleonora Sani

    2018-02-01

    Full Text Available The active galaxy NGC 1275 lies at the center of the Perseus cluster of galaxies, being an archetypal BH-galaxy system that is supposed to fit well with the MBH-host scaling relations obtained for quiescent galaxies. Since it harbors an obscured AGN, only recently our group has been able to estimate its black hole mass. Here our aim is to pinpoint NGC 1275 on the less dispersed scaling relations, namely the MBH-σ⋆ and MBH−Lbul planes. Starting from our previous work (Ricci et al., 2017a, we estimate that NGC 1275 falls well outside the intrinsic dispersion of the MBH-σ⋆ plane being 1.2 dex (in black hole mass displaced with respect to the scaling relations. We then perform a 2D morphological decomposition analysis on Spitzer/IRAC images at 3.6 μm and find that, beyond the bright compact nucleus that dominates the central emission, NGC 1275 follows a de Vaucouleurs profile with no sign of significant star formation nor clear merger remnants. Nonetheless, its displacement on the MBH−L3.6,bul plane with respect to the scaling relation is as high as observed in the MBH-σ⋆. We explore various scenarios to interpret such behaviors, of which the most realistic one is the evolutionary pattern followed by NGC 1275 to approach the scaling relation. We indeed speculate that NGC 1275 might be a specimen for those galaxies in which the black holes adjusted to its host.

  2. Peer relations scale for adolescents treated for substance use disorder: a factor analytic presentation

    Directory of Open Access Journals (Sweden)

    Yao Ping

    2012-07-01

    Full Text Available Abstract Background The literature indicates that peer relations are an important aspect of the treatment and recovery of adolescents with substance use disorder (SUD. Unfortunately, no standard measure of peer relations exists. The objective of this research is to use exploratory factor analysis to examine the underlying factor structure of a 14-item peer relations scale for use in this treatment population. Methods Participants are 509 adolescents discharged from primary substance abuse treatment from 2003–2010. The data are from research conducted between six and twelve months post discharge via a 230-item questionnaire that included the 14-item peer relations scale. The scale has questions that assess the degree to which the adolescent's social contacts conform to norms of positive behavior and therefore foster non-use and recovery. The response rate was 62%. Results The scale was decomposed by principal component factor analysis. When the matrix was rotated by varimax a three factor solution explaining 99.99% of the common variance emerged. The first factor yielded ten items that measure association with peers who engage in positive versus delinquent social behavior (positive versus negative social behavior. The three items in the second factor specify association with peers who use versus those who don’t use drugs, and thereby encourage recovery and discourage drug use (drug use. The third and factor contained two items measuring the degree to which the recovering adolescent associates with new or previous friends (post treatment peer association. Conclusions This scale is useful as a standard measure in that it begins to identify the measurable dimensions of peer relations that influence sustaining post treatment recovery.

  3. Development and psychometric testing of the Nursing Workplace Relational Environment Scale (NWRES).

    Science.gov (United States)

    Duddle, Maree; Boughton, Maureen

    2009-03-01

    The aim of this study was to develop and test the psychometric properties of the Nursing Workplace Relational Environment Scale (NWRES). A positive relational environment in the workplace is characterised by a sense of connectedness and belonging, support and cooperation among colleagues, open communication and effectively managed conflict. A poor relational environment in the workplace may contribute to job dissatisfaction and early turnover of staff. Quantitative survey. A three-stage process was used to design and test the NWRES. In Stage 1, an extensive literature review was conducted on professional working relationships and the nursing work environment. Three key concepts; collegiality, workplace conflict and job satisfaction were identified and defined. In Stage 2, a pool of items was developed from the dimensions of each concept and formulated into a 35-item scale which was piloted on a convenience sample of 31 nurses. In Stage 3, the newly refined 28-item scale was administered randomly to a convenience sample of 150 nurses. Psychometric testing was conducted to establish the construct validity and reliability of the scale. Exploratory factor analysis resulted in a 22-item scale. The factor analysis indicated a four-factor structure: collegial behaviours, relational atmosphere, outcomes of conflict and job satisfaction which explained 68.12% of the total variance. Cronbach's alpha coefficient for the NWRES was 0.872 and the subscales ranged from 0.781-0.927. The results of the study confirm the reliability and validity of the NWRES. Replication of this study with a larger sample is indicated to determine relationships among the subscales. The results of this study have implications for health managers in terms of understanding the impact of the relational environment of the workplace on job satisfaction and retention.

  4. Length of a Hanging Cable

    Directory of Open Access Journals (Sweden)

    Eric Costello

    2011-01-01

    Full Text Available The shape of a cable hanging under its own weight and uniform horizontal tension between two power poles is a catenary. The catenary is a curve which has an equation defined by a hyperbolic cosine function and a scaling factor. The scaling factor for power cables hanging under their own weight is equal to the horizontal tension on the cable divided by the weight of the cable. Both of these values are unknown for this problem. Newton's method was used to approximate the scaling factor and the arc length function to determine the length of the cable. A script was written using the Python programming language in order to quickly perform several iterations of Newton's method to get a good approximation for the scaling factor.

  5. Scale-Dependent Assessment of Relative Disease Resistance to Plant Pathogens

    Directory of Open Access Journals (Sweden)

    Peter Skelsey

    2014-03-01

    Full Text Available Phenotyping trials may not take into account sufficient spatial context to infer quantitative disease resistance of recommended varieties in commercial production settings. Recent ecological theory—the dispersal scaling hypothesis—provides evidence that host heterogeneity and scale of host heterogeneity interact in a predictable and straightforward manner to produce a unimodal (“humpbacked” distribution of epidemic outcomes. This suggests that the intrinsic artificiality (scale and design of experimental set-ups may lead to spurious conclusions regarding the resistance of selected elite cultivars, due to the failure of experimental efforts to accurately represent disease pressure in real agricultural situations. In this model-based study we investigate the interaction of host heterogeneity and scale as a confounding factor in the inference from ex-situ assessment of quantitative disease resistance to commercial production settings. We use standard modelling approaches in plant disease epidemiology and a number of different agronomic scenarios. Model results revealed that the interaction of heterogeneity and scale is a determinant of relative varietal performance under epidemic conditions. This is a previously unreported phenomenon that could provide a new basis for informing the design of future phenotyping platforms, and optimising the scale at which quantitative disease resistance is assessed.

  6. Cosmological hydrodynamical simulations of galaxy clusters: X-ray scaling relations and their evolution

    Science.gov (United States)

    Truong, N.; Rasia, E.; Mazzotta, P.; Planelles, S.; Biffi, V.; Fabjan, D.; Beck, A. M.; Borgani, S.; Dolag, K.; Gaspari, M.; Granato, G. L.; Murante, G.; Ragone-Figueroa, C.; Steinborn, L. K.

    2018-03-01

    We analyse cosmological hydrodynamical simulations of galaxy clusters to study the X-ray scaling relations between total masses and observable quantities such as X-ray luminosity, gas mass, X-ray temperature, and YX. Three sets of simulations are performed with an improved version of the smoothed particle hydrodynamics GADGET-3 code. These consider the following: non-radiative gas, star formation and stellar feedback, and the addition of feedback by active galactic nuclei (AGN). We select clusters with M500 > 1014 M⊙E(z)-1, mimicking the typical selection of Sunyaev-Zeldovich samples. This permits to have a mass range large enough to enable robust fitting of the relations even at z ˜ 2. The results of the analysis show a general agreement with observations. The values of the slope of the mass-gas mass and mass-temperature relations at z = 2 are 10 per cent lower with respect to z = 0 due to the applied mass selection, in the former case, and to the effect of early merger in the latter. We investigate the impact of the slope variation on the study of the evolution of the normalization. We conclude that cosmological studies through scaling relations should be limited to the redshift range z = 0-1, where we find that the slope, the scatter, and the covariance matrix of the relations are stable. The scaling between mass and YX is confirmed to be the most robust relation, being almost independent of the gas physics. At higher redshifts, the scaling relations are sensitive to the inclusion of AGNs which influences low-mass systems. The detailed study of these objects will be crucial to evaluate the AGN effect on the ICM.

  7. Scaling Relations of Local Magnitude versus Moment Magnitude for Sequences of Similar Earthquakes in Switzerland

    KAUST Repository

    Bethmann, F.

    2011-03-22

    Theoretical considerations and empirical regressions show that, in the magnitude range between 3 and 5, local magnitude, ML, and moment magnitude, Mw, scale 1:1. Previous studies suggest that for smaller magnitudes this 1:1 scaling breaks down. However, the scatter between ML and Mw at small magnitudes is usually large and the resulting scaling relations are therefore uncertain. In an attempt to reduce these uncertainties, we first analyze the ML versus Mw relation based on 195 events, induced by the stimulation of a geothermal reservoir below the city of Basel, Switzerland. Values of ML range from 0.7 to 3.4. From these data we derive a scaling of ML ~ 1:5Mw over the given magnitude range. We then compare peak Wood-Anderson amplitudes to the low-frequency plateau of the displacement spectra for six sequences of similar earthquakes in Switzerland in the range of 0:5 ≤ ML ≤ 4:1. Because effects due to the radiation pattern and to the propagation path between source and receiver are nearly identical at a particular station for all events in a given sequence, the scatter in the data is substantially reduced. Again we obtain a scaling equivalent to ML ~ 1:5Mw. Based on simulations using synthetic source time functions for different magnitudes and Q values estimated from spectral ratios between downhole and surface recordings, we conclude that the observed scaling can be explained by attenuation and scattering along the path. Other effects that could explain the observed magnitude scaling, such as a possible systematic increase of stress drop or rupture velocity with moment magnitude, are masked by attenuation along the path.

  8. Effect of primordial non-Gaussianities on galaxy clusters scaling relations

    Science.gov (United States)

    Trindade, A. M. M.; da Silva, Antonio

    2017-07-01

    Galaxy clusters are a valuable source of cosmological information. Their formation and evolution depends on the underlying cosmology and on the statistical nature of the primordial density fluctuations. Here we investigate the impact of primordial non-Gaussianities (PNG) on the scaling properties of galaxy clusters. We performed a series of hydrodynamic N-body simulations featuring adiabatic gas physics and different levels of non-Gaussianity within the Λ cold dark matter framework. We focus on the T-M, S-M, Y-M and YX-M scalings relating the total cluster mass with temperature, entropy and Sunyaev-Zeld'ovich integrated pressure that reflect the thermodynamic state of the intracluster medium. Our results show that PNG have an impact on cluster scalings laws. The scalings mass power-law indexes are almost unaffected by the existence of PNG, but the amplitude and redshift evolution of their normalizations are clearly affected. Changes in the Y-M and YX-M normalizations are as high as 22 per cent and 16 per cent when fNL varies from -500 to 500, respectively. Results are consistent with the view that positive/negative fNL affect cluster profiles due to an increase/decrease of cluster concentrations. At low values of fNL, as suggested by present Planck constraints on a scale invariant fNL, the impact on the scaling normalizations is only a few per cent. However, if fNL varies with scale, PNG may have larger amplitudes at clusters scales; thus, our results suggest that PNG should be taken into account when cluster data are used to infer or forecast cosmological parameters from existing or future cluster surveys.

  9. Scaling relations for use of batch data in design of reactive tracer tests

    International Nuclear Information System (INIS)

    Bahr, J.M.

    1990-01-01

    Tracer tests employing reacting solutes can be used to evaluate the rates and extents of in-situ retardation and transformation of groundwater contaminants. Preliminary estimates of retardation and transformation rates can aid in selecting appropriate input concentrations, monitoring network density and sampling schedules. Results of laboratory batch experiments provide one source of data for such estimates, as well as the basis for models that can be used to interpret tracer test results. IN some cases, batch experiments are designed to identify rate laws and rate constants for the reactions of interest. MOre frequently, however, batch experiments are conducted to determine equilibrium relations for sorption or other reversible reactions. Kinetic information provided by these equilibrium experiments generally consists only of estimated equilibration times. In this paper, analytic integrated rate laws for batch conditions are compared to results of numerical simulations of solute transport affected by homogeneous and heterogeneous reactions in order to establish scaling relations between batch equilibration times and transport times required to approach local equilibrium. For homogeneous reactions similar time scales are required for batch equilibration and to approach local equilibrium during transport. HOwever, significant differences in time scales can exist between batch and transport conditions for cases involving heterogeneous reactions. Use of the resulting scaling relations in the design of reactive tracer tests is discussed for cases of finite and continuous tracer input. (Author) (15 refs., 6 figs.)

  10. Universal scaling behaviors of meteorological variables’ volatility and relations with original records

    Science.gov (United States)

    Lu, Feiyu; Yuan, Naiming; Fu, Zuntao; Mao, Jiangyu

    2012-10-01

    Volatility series (defined as the magnitude of the increments between successive elements) of five different meteorological variables over China are analyzed by means of detrended fluctuation analysis (DFA for short). Universal scaling behaviors are found in all volatility records, whose scaling exponents take similar distributions with similar mean values and standard deviations. To reconfirm the relation between long-range correlations in volatility and nonlinearity in original series, DFA is also applied to the magnitude records (defined as the absolute values of the original records). The results clearly indicate that the nonlinearity of the original series is more pronounced in the magnitude series.

  11. UPDATED MASS SCALING RELATIONS FOR NUCLEAR STAR CLUSTERS AND A COMPARISON TO SUPERMASSIVE BLACK HOLES

    International Nuclear Information System (INIS)

    Scott, Nicholas; Graham, Alister W.

    2013-01-01

    We investigate whether or not nuclear star clusters and supermassive black holes (SMBHs) follow a common set of mass scaling relations with their host galaxy's properties, and hence can be considered to form a single class of central massive object (CMO). We have compiled a large sample of galaxies with measured nuclear star cluster masses and host galaxy properties from the literature and fit log-linear scaling relations. We find that nuclear star cluster mass, M NC , correlates most tightly with the host galaxy's velocity dispersion: log M NC = (2.11 ± 0.31)log (σ/54) + (6.63 ± 0.09), but has a slope dramatically shallower than the relation defined by SMBHs. We find that the nuclear star cluster mass relations involving host galaxy (and spheroid) luminosity and stellar and dynamical mass, intercept with but are in general shallower than the corresponding black hole scaling relations. In particular, M NC ∝M 0.55±0.15 Gal,dyn ; the nuclear cluster mass is not a constant fraction of its host galaxy or spheroid mass. We conclude that nuclear stellar clusters and SMBHs do not form a single family of CMOs.

  12. Electron beam absorption in solid and in water phantoms: depth scaling and energy-range relations

    International Nuclear Information System (INIS)

    Grosswendt, B.; Roos, M.

    1989-01-01

    In electron dosimetry energy parameters are used with values evaluated from ranges in water. The electron ranges in water may be deduced from ranges measured in solid phantoms. Several procedures recommended by national and international organisations differ both in the scaling of the ranges and in the energy-range relations for water. Using the Monte Carlo method the application of different procedures for electron energies below 10 MeV is studied for different phantom materials. It is shown that deviations in the range scaling and in the energy-range relations for water may accumulate to give energy errors of several per cent. In consequence energy-range relations are deduced for several solid phantom materials which enable a single-step energy determination. (author)

  13. Scaling relation between renormalized discharge rate and capacity in NaxCoO2 films

    Directory of Open Access Journals (Sweden)

    Ayumu Yanagita

    2015-10-01

    Full Text Available Layered cobalt oxide, P2-NaxCoO2, is a prototypical cathode material for sodium-ion secondary battery. We systematically investigated the rate dependence of the discharge capacity (Q in three thin films of Na0.68CoO2 with different film thickness (d and in-plane grain radius (r. With subtracting conventional voltage drop effect on Q, we derived an intrinsic rate dependence of Q. We found a scaling relation between the renormalized discharge rate (γ ≡ r2/DT; D and T are the Na+ diffusion constant and discharge time, respectively and relative capacity (=Q/Q0; Q0 is the value at a low rate limit. The observed scaling relation is interpreted in terms of the Na+ intercalation process at the electrolyte-NaxCoO2 interface and Na+ diffusion process within NaxCoO2.

  14. Measuring emotions during epistemic activities: the Epistemically-Related Emotion Scales.

    Science.gov (United States)

    Pekrun, Reinhard; Vogl, Elisabeth; Muis, Krista R; Sinatra, Gale M

    2017-09-01

    Measurement instruments assessing multiple emotions during epistemic activities are largely lacking. We describe the construction and validation of the Epistemically-Related Emotion Scales, which measure surprise, curiosity, enjoyment, confusion, anxiety, frustration, and boredom occurring during epistemic cognitive activities. The instrument was tested in a multinational study of emotions during learning from conflicting texts (N = 438 university students from the United States, Canada, and Germany). The findings document the reliability, internal validity, and external validity of the instrument. A seven-factor model best fit the data, suggesting that epistemically-related emotions should be conceptualised in terms of discrete emotion categories, and the scales showed metric invariance across the North American and German samples. Furthermore, emotion scores changed over time as a function of conflicting task information and related significantly to perceived task value and use of cognitive and metacognitive learning strategies.

  15. Constraints on Dark Energy, Observable-mass Scaling Relations, Neutrino Properties and Gravity from Galaxy Clusters

    DEFF Research Database (Denmark)

    Rapetti Serra, David Angelo

    Using a data set of 238 cluster detections drawn from the ROSAT All-Sky Survey and X-ray follow-up observations from the Chandra X-ray Observatory and/or ROSAT for 94 of those clusters we obtain tight constraints on dark energy, both luminosity-mass and temperature-mass scaling relations, neutrino...... properties and gravity. I will present the novel statistical framework we employed to self-consistently and simultaneously constrain cosmology and observable-mass scaling relations accounting for survey biases, parameter covariances and systematic uncertainties. Allowing the dark energy equation of state...... and the linear growth index to take any constant values, we find no evidence for departures from the standard cosmological paradigm – General Relativity plus a cosmological constant and cold dark matter. I will review in detail our results and demonstrate the power of X-ray cluster studies to constrain both...

  16. Scaling Green-Kubo Relation and Application to Three Aging Systems

    Directory of Open Access Journals (Sweden)

    A. Dechant

    2014-02-01

    Full Text Available The Green-Kubo formula relates the spatial diffusion coefficient to the stationary velocity autocorrelation function. We derive a generalization of the Green-Kubo formula that is valid for systems with long-range or nonstationary correlations for which the standard approach is no longer valid. For the systems under consideration, the velocity autocorrelation function ⟨v(t+τv(t⟩ asymptotically exhibits a certain scaling behavior and the diffusion is anomalous, ⟨x^{2}(t⟩≃2D_{ν}t^{ν}. We show how both the anomalous diffusion coefficient D_{ν} and the exponent ν can be extracted from this scaling form. Our scaling Green-Kubo relation thus extends an important relation between transport properties and correlation functions to generic systems with scale-invariant dynamics. This includes stationary systems with slowly decaying power-law correlations, as well as aging systems, systems whose properties depend on the age of the system. Even for systems that are stationary in the long-time limit, we find that the long-time diffusive behavior can strongly depend on the initial preparation of the system. In these cases, the diffusivity D_{ν} is not unique, and we determine its values, respectively, for a stationary or nonstationary initial state. We discuss three applications of the scaling Green-Kubo relation: free diffusion with nonlinear friction corresponding to cold atoms diffusing in optical lattices, the fractional Langevin equation with external noise recently suggested to model active transport in cells, and the Lévy walk with numerous applications, in particular, blinking quantum dots. These examples underline the wide applicability of our approach, which is able to treat very different mechanisms of anomalous diffusion.

  17. The constitutive relation and small scale parameter of nonlocal continuum mechanics for modelling carbon nanotubes.

    Science.gov (United States)

    Wang, Q; Wang, C M

    2007-02-21

    In this paper, the constitutive relations of nonlocal elasticity theory are presented for application in the analysis of carbon nanotubes (CNTs) when modelled as Euler-Bernoulli beams, Timoshenko beams or as cylindrical shells. In particular, the shear stress and strain relation for the nonlocal Timoshenko beam theory is discussed in great detail due to a misconception by some researchers that the nonlocal effect should appear in this constitutive relation. Different theories for proposing the value of the small scale parameter are also introduced and a recommendation for the value from the standpoint of wave propagation of CNTs is given.

  18. Analysis Method of Transfer Pricing Used by Multinational Companies Related to Tax Avoidance and its Consistencies to the Arm's Length Principle

    Directory of Open Access Journals (Sweden)

    Nuraini Sari

    2015-12-01

    Full Text Available The purpose of this study is to evaluate about how Starbucks Corporation uses transfer pricing to minimize the tax bill. In addition, the study also will evaluate how Indonesia’s domestic rules can overcome the case if Starbucks UK case happens in Indonesia. There are three steps conducted in this study. First, using information provided by UK Her Majesty's Revenue and Customs (HMRC and other related articles, find methods used by Starbucks UK to minimize the tax bill. Second, find Organisation for Economic Co-Operation and Development (OECD viewpoint regarding Starbucks Corporation cases. Third, analyze how Indonesia’s transfer pricing rules will work if Starbucks UK’s cases happened in Indonesia. The results showed that there were three inter-company transactions that helped Starbucks UK to minimize the tax bill, such as coffee costs, royalty on intangible property, and interest on inter-company loans. Through a study of OECD’s BEPS action plans, it is recommended to improve the OECD Model Tax Convention including Indonesia’s domestic tax rules in order to produce a fair and transparent judgment on transfer pricing. This study concluded that by using current tax rules, although UK HMRC has been disadvantaged because transfer pricing practices done by most of multinational companies, UK HMRC still cannot prove the transfer pricing practices are not consistent with arm’s length principle. Therefore, current international tax rules need to be improved.

  19. Mindfulness-based cancer recovery and supportive-expressive therapy maintain telomere length relative to controls in distressed breast cancer survivors.

    Science.gov (United States)

    Carlson, Linda E; Beattie, Tara L; Giese-Davis, Janine; Faris, Peter; Tamagawa, Rie; Fick, Laura J; Degelman, Erin S; Speca, Michael

    2015-02-01

    Group psychosocial interventions including mindfulness-based cancer recovery (MBCR) and supportive-expressive group therapy (SET) can help breast cancer survivors decrease distress and influence cortisol levels. Although telomere length (TL) has been associated with breast cancer prognosis, the impact of these two interventions on TL has not been studied to date. The objective of the current study was to compare the effects of MBCR and SET with a minimal intervention control condition (a 1-day stress management seminar) on TL in distressed breast cancer survivors in a randomized controlled trial. MBCR focused on training in mindfulness meditation and gentle Hatha yoga whereas SET focused on emotional expression and group support. The primary outcome measure was relative TL, the telomere/single-copy gene ratio, assessed before and after each intervention. Secondary outcomes were self-reported mood and stress symptoms. Eighty-eight distressed breast cancer survivors with a diagnosis of stage I to III cancer (using the American Joint Committee on Cancer (AJCC) TNM staging system) who had completed treatment at least 3 months prior participated. Using analyses of covariance on a per-protocol sample, there were no differences noted between the MBCR and SET groups with regard to the telomere/single-copy gene ratio, but a trend effect was observed between the combined intervention group and controls (F [1,84], 3.82; P = .054; η(2)  = .043); TL in the intervention group was maintained whereas it was found to decrease for control participants. There were no associations noted between changes in TL and changes in mood or stress scores over time. Psychosocial interventions providing stress reduction and emotional support resulted in trends toward TL maintenance in distressed breast cancer survivors, compared with decreases in usual care. © 2014 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.

  20. Gauge-Independent Scales Related to the Standard Model Vacuum Instability

    CERN Document Server

    Espinosa, Jose R.; Konstandin, Thomas; Riotto, Antonio

    2017-01-01

    The measured (central) values of the Higgs and top quark masses indicate that the Standard Model (SM) effective potential develops an instability at high field values. The scale of this instability, determined as the Higgs field value at which the potential drops below the electroweak minimum, is about $10^{11}$ GeV. However, such a scale is unphysical as it is not gauge-invariant and suffers from a gauge-fixing uncertainty of up to two orders of magnitude. Subjecting our system, the SM, to several probes of the instability (adding higher order operators to the potential; letting the vacuum decay through critical bubbles; heating up the system to very high temperature; inflating it) and asking in each case physical questions, we are able to provide several gauge-invariant scales related with the Higgs potential instability.

  1. Gauge-independent scales related to the Standard Model vacuum instability

    International Nuclear Information System (INIS)

    Espinosa, J.R.; Garny, M.; Konstandin, T.; Riotto, A.

    2016-08-01

    The measured (central) values of the Higgs and top quark masses indicate that the Standard Model (SM) effective potential develops an instability at high field values. The scale of this instability, determined as the Higgs field value at which the potential drops below the electroweak minimum, is about 10 11 GeV. However, such a scale is unphysical as it is not gauge invariant and suffers from a gauge-fixing uncertainty of up to two orders of magnitude. Subjecting our system, the SM, to several probes of the instability (adding higher order operators to the potential; letting the vacuum decay through critical bubbles; heating up the system to very high temperature; inflating it) and asking in each case physical questions, we are able to provide several gauge-invariant scales related with the Higgs potential instability.

  2. Scaling relations of three-dimensional random-exchange quantum antiferromagnets

    Science.gov (United States)

    Tan, Deng-Ruei; Jiang, Fu-Jiun

    2015-11-01

    The thermal and ground state properties of a class of three-dimensional (3D) random-exchange spin-1/2 antiferromagnets are studied using first principles quantum Monte Carlo method. Our motivation is to examine whether the newly discovered universal scaling properties, which connect the Néel temperature and the staggered magnetization density, for the clean 3D quantum dimerized Heisenberg models remain valid for the random-exchange models considered here. Remarkably, similar to the clean systems, our Monte Carlo results indicate that these scaling relations also emerge for the considered models with the introduced antiferromagnetic randomness. The scope of the validity of these scaling properties for the 3D quantum antiferromagnets is investigated as well.

  3. Cultural adaptation of the Tuberculosis-related stigma scale to Brazil.

    Science.gov (United States)

    Crispim, Juliane de Almeida; Touso, Michelle Mosna; Yamamura, Mellina; Popolin, Marcela Paschoal; Garcia, Maria Concebida da Cunha; Santos, Cláudia Benedita Dos; Palha, Pedro Fredemir; Arcêncio, Ricardo Alexandre

    2016-06-01

    The process of stigmatization associated with TB has been undervalued in national research as this social aspect is important in the control of the disease, especially in marginalized populations. This paper introduces the stages of the process of cultural adaptation in Brazil of the Tuberculosis-related stigma scale for TB patients. It is a methodological study in which the items of the scale were translated and back-translated with semantic validation with 15 individuals of the target population. After translation, the reconciled back-translated version was compared with the original version by the project coordinator in Southern Thailand, who approved the final version in Brazilian Portuguese. The results of the semantic validation conducted with TB patients enable the identification that, in general, the scale was well accepted and easily understood by the participants.

  4. The Mini-IPIP Scale: psychometric features and relations with PTSD symptoms of Chinese earthquake survivors.

    Science.gov (United States)

    Li, Zhongquan; Sang, Zhiqin; Wang, Li; Shi, Zhanbiao

    2012-10-01

    The present purpose was to validate the Mini-IPIP scale, a short measure of the five-factor model personality traits, with a sample of Chinese earthquake survivors. A total of 1,563 participants, ages 16 to 85 years, completed the Mini-IPIP scale and a measure of posttraumatic stress disorder (PTSD) symptoms. Confirmatory factor analysis supported the five-factor structure of the Mini-IPIP with adequate values of various fit indices. This scale also showed values of internal consistency, Cronbach's alphas ranged from .79 to .84, and McDonald's omega ranged from .73 to .82 for scores on each subscale. Moreover, the five personality traits measured by the Mini-IPIP and those assessed by other big five measures had comparable patterns of relations with PTSD symptoms. Findings indicated that the Mini-IPIP is an adequate short-form of the Big-Five factors of personality, which is applicable with natural disaster survivors.

  5. Evaluating broad scale patterns among related species using resource experiments in tropical hummingbirds.

    Science.gov (United States)

    Weinstein, Ben G; Graham, Catherine H

    2016-08-01

    A challenge in community ecology is connecting biogeographic patterns with local scale observations. In Neotropical hummingbirds, closely related species often co-occur less frequently than expected (overdispersion) when compared to a regional species pool. While this pattern has been attributed to interspecific competition, it is important to connect these findings with local scale mechanisms of coexistence. We measured the importance of the presence of competitors and the availability of resources on selectivity at experimental feeders for Andean hummingbirds along a wide elevation gradient. Selectivity was measured as the time a bird fed at a feeder with a high sucrose concentration when presented with feeders of both low and high sucrose concentrations. Resource selection was measured using time-lapse cameras to identity which floral resources were used by each hummingbird species. We found that the increased abundance of preferred resources surrounding the feeder best explained increased species selectivity, and that related hummingbirds with similar morphology chose similar floral resources. We did not find strong support for direct agonism based on differences in body size or phylogenetic relatedness in predicting selectivity. These results suggest closely related hummingbird species have overlapping resource niches, and that the intensity of interspecific competition is related to the abundance of those preferred resources. If these competitive interactions have negative demographic effects, our results could help explain the pattern of phylogenetic overdispersion observed at regional scales. © 2016 by the Ecological Society of America.

  6. Testing the Abbreviated Food Technology Neophobia Scale and its relation to satisfaction with food-related life in university students.

    Science.gov (United States)

    Schnettler, Berta; Grunert, Klaus G; Miranda-Zapata, Edgardo; Orellana, Ligia; Sepúlveda, José; Lobos, Germán; Hueche, Clementina; Höger, Yesli

    2017-06-01

    The aims of this study were to test the relationships between food neophobia, satisfaction with food-related life and food technology neophobia, distinguishing consumer segments according to these variables and characterizing them according to willingness to purchase food produced with novel technologies. A survey was conducted with 372 university students (mean aged=20.4years, SD=2.4). The questionnaire included the Abbreviated version of the Food Technology Neophobia Scale (AFTNS), Satisfaction with Life Scale (SWLS), and a 6-item version of the Food Neophobia Scale (FNS). Using confirmatory factor analysis, it was confirmed that SWFL correlated inversely with FNS, whereas FNS correlated inversely with AFTNS. No relationship was found between SWFL and AFTNS. Two main segments were identified using cluster analysis; these segments differed according to gender and family size. Group 1 (57.8%) possessed higher AFTNS and FNS scores than Group 2 (28.5%). However, these groups did not differ in their SWFL scores. Group 1 was less willing to purchase foods produced with new technologies than Group 2. The AFTNS and the 6-item version of the FNS are suitable instruments to measure acceptance of foods produced using new technologies in South American developing countries. The AFTNS constitutes a parsimonious alternative for the international study of food technology neophobia. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Two scale damage model and related numerical issues for thermo-mechanical high cycle fatigue

    International Nuclear Information System (INIS)

    Desmorat, R.; Kane, A.; Seyedi, M.; Sermage, J.P.

    2007-01-01

    On the idea that fatigue damage is localized at the microscopic scale, a scale smaller than the mesoscopic one of the Representative Volume Element (RVE), a three-dimensional two scale damage model has been proposed for High Cycle Fatigue applications. It is extended here to aniso-thermal cases and then to thermo-mechanical fatigue. The modeling consists in the micro-mechanics analysis of a weak micro-inclusion subjected to plasticity and damage embedded in an elastic meso-element (the RVE of continuum mechanics). The consideration of plasticity coupled with damage equations at micro-scale, altogether with Eshelby-Kroner localization law, allows to compute the value of microscopic damage up to failure for any kind of loading, 1D or 3D, cyclic or random, isothermal or aniso-thermal, mechanical, thermal or thermo-mechanical. A robust numerical scheme is proposed in order to make the computations fast. A post-processor for damage and fatigue (DAMAGE-2005) has been developed. It applies to complex thermo-mechanical loadings. Examples of the representation by the two scale damage model of physical phenomena related to High Cycle Fatigue are given such as the mean stress effect, the non-linear accumulation of damage. Examples of thermal and thermo-mechanical fatigue as well as complex applications on real size testing structure subjected to thermo-mechanical fatigue are detailed. (authors)

  8. Validation of sleep-related breathing disorder scale in Hong Kong Chinese snoring children.

    Science.gov (United States)

    Chan, Amy; Chan, Chung-Hong; Ng, Daniel K

    2012-08-01

    The purpose of this study is to validate the previously-validated Taiwan Chinese version of Sleep-Related Breathing Disorder scale (SRBD scale) in Hong Kong Chinese snoring children. SRBD scale is an instrument used for prediction of obstructive sleep apnea syndrome. (OSA) The Chinese version of SRBD scale were previously translated and validated in Taiwan. The same questionnaire were administered in a group of 102 snoring children (mean age: 10.7 and 65 boys) from a sleep laboratory in Hong Kong before their sleep studies. The SRBD scores were then validated against the results from sleep studies. By using the definition of apnea-hypopnea index larger than 1.5 as OSA, 28 children (27.5%) had polysomnography-confirmed OSA. The sensitivity, specificity, positive likelihood ratio and negative likelihood ratio of the previously validated cut-off of SRBD score > 0.33 for OSA were 0.5, 0.55, 1.12, and 0.90, respectively. The area under ROC curve was only 0.58, indicates suboptimal performance of SRBD score in predicting OSA. In summary, our study concluded that the previously reported Chinese SRBD scale is not accurate in identifying presence of OSA in Hong Kong Chinese snoring children. Copyright © 2012 Wiley Periodicals, Inc.

  9. Mental Illness Related Internalized Stigma: Psychometric Properties of the Brief ISMI Scale in Greece.

    Science.gov (United States)

    Paraskevoulakou, Alexia; Vrettou, Kassiani; Pikouli, Katerina; Triantafillou, Evgenia; Lykou, Anastasia; Economou, Marina

    2017-09-01

    Since evaluation regarding the impact of mental illness related internalized stigma is scarce, there is a great need for psychometric instruments which could contribute to understanding its adverse effects among Greek patients with severe mental illness. The Brief Internalized Stigma of Mental Illness (ISMI) scale is one of the most widely used measures designed to assess the subjective experience of stigma related to mental illness. The present study aimed to investigate the psychometric properties of the Greek version of the Brief ISMI scale. In addition to presenting psychometric findings, we explored the relationship of the Greek version of the Brief ISMI subscales with indicators of self-esteem and quality of life. 272 outpatients (108 males, 164 females) meeting the DSM-IV TR criteria for severe mental disorder (schizophrenia, bipolar disorder, major depression) completed the Brief ISMI, the RSES and the WHOQOL-BREF scales. Patients reported age and educational level. A retest was conducted with 124 patients. The Chronbach's alpha coefficient was 0 0.83. The test-retest reliability coefficients varied from 0.81 to 0.91, indicating substantial agreement. The ICC was for the total score 0.83 and for the two factors, 0.69 and 0.77 respectively. Factor analysis provided strong evidence for a two factor model. Factors 1 and 2 were named respectively "how others view me" and "how I view myself". They were negatively correlated with both RSES and WHOQOL-BREF scales, as well as with educational level. Factor 2 was significantly associated with the type of diagnosis. The Greek version of the Brief ISMI scale can be used as a reliable and valid tool for assessing mental illness related internalized stigma among Greek patients with severe mental illness.

  10. Selective vulnerability related to aging in large-scale resting brain networks.

    Science.gov (United States)

    Zhang, Hong-Ying; Chen, Wen-Xin; Jiao, Yun; Xu, Yao; Zhang, Xiang-Rong; Wu, Jing-Tao

    2014-01-01

    Normal aging is associated with cognitive decline. Evidence indicates that large-scale brain networks are affected by aging; however, it has not been established whether aging has equivalent effects on specific large-scale networks. In the present study, 40 healthy subjects including 22 older (aged 60-80 years) and 18 younger (aged 22-33 years) adults underwent resting-state functional MRI scanning. Four canonical resting-state networks, including the default mode network (DMN), executive control network (ECN), dorsal attention network (DAN) and salience network, were extracted, and the functional connectivities in these canonical networks were compared between the younger and older groups. We found distinct, disruptive alterations present in the large-scale aging-related resting brain networks: the ECN was affected the most, followed by the DAN. However, the DMN and salience networks showed limited functional connectivity disruption. The visual network served as a control and was similarly preserved in both groups. Our findings suggest that the aged brain is characterized by selective vulnerability in large-scale brain networks. These results could help improve our understanding of the mechanism of degeneration in the aging brain. Additional work is warranted to determine whether selective alterations in the intrinsic networks are related to impairments in behavioral performance.

  11. Role of duration of catheterization and length of hospital stay on the rate of catheter-related hospital-acquired urinary tract infections

    Directory of Open Access Journals (Sweden)

    Al-Hazmi H

    2015-03-01

    Full Text Available Hamdan Al-HazmiDivision of Urology, Department of Surgery, College of Medicine and King Khalid University Hospital, King Saud University, Riyadh, Saudi ArabiaObjective: Our aim is to prove that duration of catheterization and length of hospital stay (LOS are associated with the rate of hospital-acquired urinary tract infections (UTI, while taking into account type of urinary catheter used, the most common organisms found, patient diagnosis on admission, associated comorbidities, age, sex, precautions that should be taken to avoid UTI, and comparison with other studies.Methods: The study was done in a university teaching hospital with a 920-bed capacity; this hospital is a tertiary care center in Riyadh, Saudi Arabia. The study was done on 250 selected patients during the year 2010 as a retrospective descriptive study. Patients were selected as purposive sample, all of them having been exposed to urinary catheterization; hospital-acquired UTI were found in 100 patients. Data were abstracted from the archived patients' files in the medical record department using the annual infection control logbook prepared by the infection control department. The data collected were demographic information about the patients, clinical condition (diagnosis and the LOS, and possible risk factors for infection such as duration of catheterization, exposure to invasive devices or surgical procedures, and medical condition.Results: There was a statistically significant association between the rate of UTI and duration of catheterization: seven patients had UTI out of 46 catheterized patients (15% at 3 days of catheterization, while 30 patients had UTI out of 44 catheterized patients (68% at 8 days of catheterization (median 8 days in infected patients versus 3 days in noninfected patients; P-value <0.05, which means that the longer the duration of catheterization, the higher the UTI rate. There was a statistically significant association between the rate of UTI and LOS

  12. [Scale Relativity Theory in living beings morphogenesis: fratal, determinism and chance].

    Science.gov (United States)

    Chaline, J

    2012-10-01

    The Scale Relativity Theory has many biological applications from linear to non-linear and, from classical mechanics to quantum mechanics. Self-similar laws have been used as model for the description of a huge number of biological systems. Theses laws may explain the origin of basal life structures. Log-periodic behaviors of acceleration or deceleration can be applied to branching macroevolution, to the time sequences of major evolutionary leaps. The existence of such a law does not mean that the role of chance in evolution is reduced, but instead that randomness and contingency may occur within a framework which may itself be structured in a partly statistical way. The scale relativity theory can open new perspectives in evolution. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  13. Single-field consistency relations of large scale structure part III: test of the equivalence principle

    Energy Technology Data Exchange (ETDEWEB)

    Creminelli, Paolo [Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, Trieste, 34151 (Italy); Gleyzes, Jérôme; Vernizzi, Filippo [CEA, Institut de Physique Théorique, Gif-sur-Yvette cédex, F-91191 France (France); Hui, Lam [Physics Department and Institute for Strings, Cosmology and Astroparticle Physics, Columbia University, New York, NY, 10027 (United States); Simonović, Marko, E-mail: creminel@ictp.it, E-mail: jerome.gleyzes@cea.fr, E-mail: lhui@astro.columbia.edu, E-mail: msimonov@sissa.it, E-mail: filippo.vernizzi@cea.fr [SISSA, via Bonomea 265, Trieste, 34136 (Italy)

    2014-06-01

    The recently derived consistency relations for Large Scale Structure do not hold if the Equivalence Principle (EP) is violated. We show it explicitly in a toy model with two fluids, one of which is coupled to a fifth force. We explore the constraints that galaxy surveys can set on EP violation looking at the squeezed limit of the 3-point function involving two populations of objects. We find that one can explore EP violations of order 10{sup −3}÷10{sup −4} on cosmological scales. Chameleon models are already very constrained by the requirement of screening within the Solar System and only a very tiny region of the parameter space can be explored with this method. We show that no violation of the consistency relations is expected in Galileon models.

  14. The Debye light scattering equation’s scaling relation reveals the purity of synthetic dendrimers

    International Nuclear Information System (INIS)

    Tseng, Hui-Yu; Chen, Hsiao-Ping; Tang, Yi-Hsuan; Chen, Hui-Ting; Kao, Chai-Lin; Wang, Shau-Chun

    2016-01-01

    Spherical dendrimer structures cannot be structurally modeled using conventional polymer models of random coil or rod-like configurations during the calibration of the static light scattering (LS) detectors used to determine the molecular weight (M.W.) of a dendrimer or directly assess the purity of a synthetic compound. In this paper, we used the Debye equation-based scaling relation, which predicts that the static LS intensity per unit concentration is linearly proportional to the M.W. of a synthetic dendrimer in a dilute solution, as a tool to examine the purity of high-generational compounds and to monitor the progress of dendrimer preparations. Without using expensive equipment, such as nuclear magnetic resonance or mass spectrometry, this method only required an affordable flow injection set-up with an LS detector. Solutions of the purified dendrimers, including the poly(amidoamine) (PAMAM) dendrimer and its fourth to seventh generation pyridine derivatives with size range of 5–9 nm, were used to establish the scaling relation with high linearity. The use of artificially impure mixtures of six or seven generations revealed significant deviations from linearity. The raw synthesized products of the pyridine-modified PAMAM dendrimer, which included incompletely reacted dendrimers, were also examined to gauge the reaction progress. As a reaction toward a particular generational derivative of the PAMAM dendrimers proceeded over time, deviations from the linear scaling relation decreased. The difference between the polydispersity index of the incompletely converted products and that of the pure compounds was only about 0.01. The use of the Debye equation-based scaling relation, therefore, is much more useful than the polydispersity index for monitoring conversion processes toward an indicated functionality number in a given preparation.Graphical abstract

  15. The Debye light scattering equation’s scaling relation reveals the purity of synthetic dendrimers

    Energy Technology Data Exchange (ETDEWEB)

    Tseng, Hui-Yu; Chen, Hsiao-Ping [National Chung Cheng University, Department of Chemistry and Biochemistry (China); Tang, Yi-Hsuan [Kaohsiung Medical University, Department of Medicinal and Applied Chemistry (China); Chen, Hui-Ting [Kaohsiung Medical University, Department of Fragrance and Cosmetic Science (China); Kao, Chai-Lin, E-mail: clkao@kmu.edu.tw [Kaohsiung Medical University, Department of Medicinal and Applied Chemistry (China); Wang, Shau-Chun, E-mail: chescw@ccu.edu.tw [National Chung Cheng University, Department of Chemistry and Biochemistry (China)

    2016-03-15

    Spherical dendrimer structures cannot be structurally modeled using conventional polymer models of random coil or rod-like configurations during the calibration of the static light scattering (LS) detectors used to determine the molecular weight (M.W.) of a dendrimer or directly assess the purity of a synthetic compound. In this paper, we used the Debye equation-based scaling relation, which predicts that the static LS intensity per unit concentration is linearly proportional to the M.W. of a synthetic dendrimer in a dilute solution, as a tool to examine the purity of high-generational compounds and to monitor the progress of dendrimer preparations. Without using expensive equipment, such as nuclear magnetic resonance or mass spectrometry, this method only required an affordable flow injection set-up with an LS detector. Solutions of the purified dendrimers, including the poly(amidoamine) (PAMAM) dendrimer and its fourth to seventh generation pyridine derivatives with size range of 5–9 nm, were used to establish the scaling relation with high linearity. The use of artificially impure mixtures of six or seven generations revealed significant deviations from linearity. The raw synthesized products of the pyridine-modified PAMAM dendrimer, which included incompletely reacted dendrimers, were also examined to gauge the reaction progress. As a reaction toward a particular generational derivative of the PAMAM dendrimers proceeded over time, deviations from the linear scaling relation decreased. The difference between the polydispersity index of the incompletely converted products and that of the pure compounds was only about 0.01. The use of the Debye equation-based scaling relation, therefore, is much more useful than the polydispersity index for monitoring conversion processes toward an indicated functionality number in a given preparation.Graphical abstract.

  16. On the use of calibrated relative paleointensity records to improve millennial-scale geomagnetic field models

    OpenAIRE

    Monika Korte; C. Constable

    2006-01-01

    Current millennial-scale time-varying global geomagnetic field models suffer from a lack of intensity data compared to directional data, because only thermoremanently magnetized material can provide absolute information about the past field strength. The number of archeomagnetic artefacts that can provide such data diminishes rapidly prior to 3000 BC. Sediment cores provide time series of declination and inclination and of variations of magnetization: the latter can reflect relative geomagne...

  17. Illness Attitudes Scale dimensions and their associations with anxiety-related constructs in a nonclinical sample.

    Science.gov (United States)

    Stewart, S H; Watt, M C

    2000-01-01

    The Illness Attitudes Scale (IAS) is a self-rated measure that consists of nine subscales designed to assess fears, attitudes and beliefs associated with hypochondriacal concerns and abnormal illness behavior [Kellner, R. (1986). Somatization and hypochondriasis. New York: Praeger; Kellner, R. (1987). Abridged manual of the Illness Attitudes Scale. Department of Psychiatry, School of Medicine, University of New Mexico]. The purposes of the present study were to explore the hierarchical factor structure of the IAS in a nonclinical sample of young adult volunteers and to examine the relations of each illness attitudes dimension to a set of anxiety-related measures. One-hundred and ninety-seven undergraduate university students (156 F, 41 M; mean age = 21.9 years) completed the IAS as well as measures of anxiety sensitivity, trait anxiety and panic attack history. The results of principal components analyses with oblique (Oblimin) rotation suggested that the IAS is best conceptualized as a four-factor measure at the lower order level (with lower-order dimensions tapping illness-related Fears, Behavior, Beliefs and Effects, respectively), and a unifactorial measure at the higher-order level (i.e. higher-order dimension tapping General Hypochondriacal Concerns). The factor structure overlapped to some degree with the scoring of the IAS proposed by Kellner (1986, 1987), as well as with the factor structures identified in previously-tested clinical and nonclinical samples [Ferguson, E. & Daniel, E. (1995). The Illness Attitudes Scale (IAS): a psychometric evaluation on a nonclinical population. Personality and Individual Differences, 18, 463-469; Hadjistavropoulos, H. D. & Asmundson, G. J. G. (1998). Factor analytic investigation of the Illness Attitudes Scale in a chronic pain sample. Behaviour Research and Therapy, 36, 1185-1195; Hadjistavropoulos, H. D., Frombach, I. & Asmundson, G. J. G. (in press). Exploratory and confirmatory factor analytic investigations of the

  18. The MUSIC of galaxy clusters - II. X-ray global properties and scaling relations

    Science.gov (United States)

    Biffi, V.; Sembolini, F.; De Petris, M.; Valdarnini, R.; Yepes, G.; Gottlöber, S.

    2014-03-01

    We present the X-ray properties and scaling relations of a large sample of clusters extracted from the Marenostrum MUltidark SImulations of galaxy Clusters (MUSIC) data set. We focus on a sub-sample of 179 clusters at redshift z ˜ 0.11, with 3.2 × 1014 h-1 M⊙ observations and derive observable-like global properties of the intracluster medium (ICM), as X-ray temperature (TX) and luminosity (LX). TX is found to slightly underestimate the true mass-weighted temperature, although tracing fairly well the cluster total mass. We also study the effects of TX on scaling relations with cluster intrinsic properties: total (M500 and gas Mg,500 mass; integrated Compton parameter (YSZ) of the Sunyaev-Zel'dovich (SZ) thermal effect; YX = Mg,500 TX. We confirm that YX is a very good mass proxy, with a scatter on M500-YX and YSZ-YX lower than 5 per cent. The study of scaling relations among X-ray, intrinsic and SZ properties indicates that simulated MUSIC clusters reasonably resemble the self-similar prediction, especially for correlations involving TX. The observational approach also allows for a more direct comparison with real clusters, from which we find deviations mainly due to the physical description of the ICM, affecting TX and, particularly, LX.

  19. Chromosome length scaling in haploid, asexual reproduction

    International Nuclear Information System (INIS)

    Oliveira, P M C de

    2007-01-01

    We study the genetic behaviour of a population formed by haploid individuals which reproduce asexually. The genetic information for each individual is stored along a bit-string (or chromosome) with L bits, where 0-bits represent the wild allele and 1-bits correspond to harmful mutations. Each newborn inherits this chromosome from its parent with a few random mutations: on average a fixed number m of bits are flipped. Selection is implemented according to the number N of 1-bits counted along the individual's chromosome: the smaller N the higher the probability an individual has to survive a new time step. Such a population evolves, with births and deaths, and its genetic distribution becomes stabilized after sufficiently many generations have passed. The question we pose concerns the procedure of increasing L. The aim is to get the same distribution of genetic loads N/L among the equilibrated population, in spite of a larger L. Should we keep the same mutation rate m/L for different values of L? The answer is yes, which intuitively seems to be plausible. However, this conclusion is not trivial, according to our simulation results: the question also involves the population size

  20. Scale Length of the Galactic Thin Disk

    Indian Academy of Sciences (India)

    Since January 2016, the Journal of Astrophysics and Astronomy has moved to Continuous Article Publishing (CAP) mode. This means that each accepted article is being published immediately online with DOI and article citation ID with starting page number 1. Articles are also visible in Web of Science immediately.