bluuebunny/crossref_metadata_2025 huggingface dataset:
International Terrorism and the Clash of Civilizations
Authors: Neumayer Eric , Plümper Thomas
Published: July 2009

Huntington referred to a ‘clash of civilizations’ revealing itself in international terrorism, particularly in the clash between the Islamic civilization and the West. The authors confront his hypotheses with ones derived from the strategic logic of international terrorism. They predict more terrorism against nationals from countries whose governments support the government of the terrorists’ home country. Like Huntington, they also predict excessive terrorism on Western targets, not because of inter-civilizational conflict per se, but because of the strategic value of Western targets. Contra Huntington, their theory does not suggest that Islamic civilization groups commit more terrorist acts against nationals from other civilizations in general, nor a general increase in inter-civilizational terrorism after the Cold War. The empirical analysis – based on estimations in a directed dyadic country sample, 1969–2005 – broadly supports their theory. In particular, there is not significantly more terrorism from the Islamic against other civilizations in general, nor a structural break in the pattern of international terrorism after the Cold War.
On the development of internal chemical zonation in small mafic dykes
Authors: CHISTYAKOVA SOFYA , LATYPOV RAIS
Published: July 2009

Three dolerite dykes (Small, 3.2 cm; Middle, 13.5 cm; Thick, 50 cm) from Torsholma Island, SW Finland, reveal distinctly different internal zonation that becomes more complicated with increasing thickness of the dykes. The Small Dyke shows a systematic inward increase in normative Pl (An+Ab+Or) and a decrease in normative An (100*An/(An+Ab)), whole-rock MgO, Mg number (100*Mg/(Mg+Fetotal)), TiO2, K2O and Zr. The Middle Dyke exhibits the same compositional pattern at the margins, while the centre is distinguished by an abrupt increase in normative Pl and An, whole-rock Sr and Mg number. From the margins inwards, the Thick Dyke displays first a compositional pattern identical to that observed in the Small Dyke and the margins of the Middle Dyke. This is followed by a region where whole-rock MgO, Mg number and normative An start increasing inwards, while the transition to the centre of the dyke is characterized by a compositional pattern similar to that in the centre of Middle Dyke. The origin of chemical zonation in these dykes is attributed to the operation of three independent physico-chemical processes, namely: the Small Dyke formed exclusively by progressive changes in the composition of inflowing magma; the Middle Dyke by changes in composition of inflowing magma (margins) and concentration of plagioclase and olivine phenocrysts by flow differentiation (centre); the Thick Dyke by changes in composition of inflowing magma (margins),in situcumulate growth against dyke sidewalls (middle) and flow differentiation (centre). Systematic changes in these processes and, as a result, in internal chemical zonation, likely take place in response to crystallization of magma under less supercooled conditions with increasing dyke thickness. A comprehensive geochemical study of the internal zonation of small mafic dykes worldwide is required to develop a complete understanding of the processes operating in mafic dykes.
EXPLORING SOCIOECONOMIC VULNERABILITY OF ANAEMIA AMONG WOMEN IN EASTERN INDIAN STATES
Authors: GHOSH SASWATA
Published: July 2009

The present study investigates the socioeconomic risk factors of anaemia among women belonging to eastern Indian states. An attempt has been made to find out differences in anaemia related to social class and place of residence, and age and marital status. It was hypothesized that rural women would have a higher prevalence of anaemia compared with their urban counterparts, particularly among the poorest social strata, and that ever-married women would be at elevated risk of anaemia compared with never-married women, particularly in the adolescent age group. Using data from National Family Health Survey-3, 2005–6, a nationally representative cross-sectional survey that provided information on anaemia level among 19,695 women of this region, the present study found that the prevalence of anaemia was high among all women cutting across social class, location and other attributes. In all 47.9% were mildly anaemic (10.0–11.9.9 g/dl), 16.1% were moderately anaemic (7.0–9.9 g/dl) and 1.6% were severely anaemic (<7.0 g/dl). Protective factors include frequent consumption of pulses, milk and milk products, fruits and fish, educational attainment, mass media exposure and high socioeconomic status. Urban poor women and adolescent ever-married women had very high odds of being anaemic. New programme strategies are needed, particularly those that improve iron storage and enhance the overall nutritional status of women throughout the life-cycle.
Momentum and scalar transport at the turbulent/non-turbulent interface of a jet
Authors: WESTERWEEL J. , FUKUSHIMA C. , PEDERSEN J. M. , HUNT J. C. R.
Published: July 2009

Conditionally sampled measurements withparticle image velocimetry(PIV) of a turbulent round submerged liquid jet in a laboratory have been taken atRe= 2 × 103between 60 and 100 nozzle diameters from the nozzle in order to investigate the dynamics and transport processes at the continuous and well-defined bounding interface between the turbulent and non-turbulent regions of flow. The jet carries a fluorescent dye measured with planarlaser-induced fluorescence(LIF), and the surface discontinuity in the scalar concentration is identified as the fluctuating turbulent jet interface. Thence the mean outward ‘boundary entrainment’ velocity is derived and shown to be a constant fraction (about 0.07) of the the mean jet velocity on the centreline. Profiles of the conditional mean velocity, mean scalar and momentum flux show that at the interface there are clear discontinuities in the mean axial velocity and mean scalar and a tendency towards a singularity in mean vorticity. These actual or asymptotic discontinuities are consistent with the conditional mean momentum and scalar transport equations integrated across the interface. Measurements of the fluxes of turbulent kinetic energy and enstrophy are consistent with computations by Mathew & Basu (Phys. Fluids, vol. 14, 2002, pp. 2065–2072) in showing that for a jet flow (without forcing) the entrainment process is dominated by small-scale eddying at the highly sheared interface (‘nibbling’), with large-scale engulfing making a small (less than 10%) contribution consistent with concentration measurements showing that the interior of the jet is well mixed. (Turbulent jets differ greatly from the free shear layer in this respect.) To explain the difference between velocity and scalar profiles, their conditional mean gradients are defined in terms of a local eddy viscosity and eddy diffusivity and the momentum and scalar fluxes inside the interface. Since the eddy diffusivity is larger than the eddy viscosity, the scalar profile is flatter inside the interface so that the scalar discontinuity is relatively greater than the mean velocity discontinuity. Theoretical arguments, following Hunt, Eames & Westerweel (inProc. of the IUTAM Symp. on Computational Physics and New Perspectives in Turbulence, ed. Y. Kaneda, vol. 4, 2008, pp. 331–338, Springer), are proposed for how the vortex sheet develops, how the internal structure of the interface layer relates to the inhomogeneous rotational and irrotational motions on each side and why the dominant entrainment process of jets and wakes differs from that of free shear layers.
Gravity currents impinging on bottom-mounted square cylinders: flow fields and associated forces
Authors: GONZALEZ-JUEZ E. , MEIBURG E. , CONSTANTINESCU G.
Published: July 2009

The unsteady drag and lift generated by the interaction of a gravity current with a bottom-mounted square cylinder are investigated by means of high-resolution Navier–Stokes simulations. Two-dimensional simulations for Reynolds numbers (Re) O(1000) and three-dimensional simulations for Re = O(10000) demonstrate that the drag coefficient increases exponentially towards a maximum as the current meets the cylinder, then undergoes strong fluctuations and eventually approaches a quasi-steady value. The simulation results show that the maximum drag coefficient can reach a value of 3, with the quasi-steady value being O(1), which should aid in selecting a design drag coefficient for submarine structures under the potential impact of gravity currents. The transient drag and lift fluctuations after impact are associated with the Kelvin–Helmholtz vortices in the mixing layer between the gravity current and the ambient fluid. As these vortices pass over the cylinder, they cause the convection of separated flow regions along the bottom wall towards the cylinder. In two-dimensional simulations at Re = O(10000), these flow structures are seen to be unrealistically coherent and to persist throughout the interaction, thus resulting in a noticeable overprediction of the drag and lift fluctuations. On the other hand, the impact of the current on the cylinder is seen to be very well captured by two-dimensional simulations at all Re values. Three-dimensional simulations lead to excellent agreement with available experimental data throughout the flow/structure interaction. They show that the spanwise variation of the drag is determined by the gravity current's lobe-and-cleft structure at impact and by an unsteady cellular flow structure similar to that found in constant-density flows at later times. A comparison between gravity-current flows and corresponding constant-density flows shows the hydrostatic drag component to be important for gravity currents.
A reformulation and applications of interfacial fluids with a free surface
Authors: HAUT T. S. , ABLOWITZ M. J.
Published: July 2009

A non-local formulation, depending on a free spectral parameter, is presented governing two ideal fluids separated by a free interface and bounded above either by a free surface or by a rigid lid. This formulation is shown to be related to the Dirichlet–Neumann operators associated with the two-fluid equations. As an application, long wave equations are obtained; these include generalizations of the Benney–Luke and intermediate long wave equations, as well as their higher order perturbations. Computational studies reveal that both equations possess lump-type solutions, which indicate the possible existence of fully localized solitary waves in interfacial fluids with sufficient surface tension.
Anomalous pressure drop behaviour of mixed kinematics flows of viscoelastic polymer solutions: a multiscale simulation approach
Authors: KOPPOL ANANTHA P. , SURESHKUMAR RADHAKRISHNA , ABEDIJABERI ARASH , KHOMAMI BAMIN
Published: July 2009

A long-standing unresolved problem in non-Newtonian fluid mechanics, namely, the relationship between friction drag and flow rate in inertialess complex kinematics flows of dilute polymeric solutions is investigated via self-consistent multiscale flow simulations. Specifically, flow of a highly elastic dilute polymeric solution, described by first principles micromechanical models, through a 4:1:4 axisymmetric contraction and expansion geometry is examined utilizing our recently developed highly efficient multiscale flow simulation algorithm (Koppol, Sureshkumar & Khomami, J. Non-Newtonian Fluid Mech., vol. 141, 2007, p. 180). Comparison with experimental measurements (Rothstein & McKinley, J. Non-Newtonian Fluid Mech., vol. 86, 1999, p. 61) shows that the pressure drop evolution as a function of flow rate can be accurately predicted when the chain dynamics is described by multi-segment bead-spring micromechanical models that closely capture the transient extensional viscosity of the experimental fluid. Specifically, for the first time the experimentally observed doubling of the dimensionless excess pressure drop at intermediate flow rates is predicted. Moreover, based on an energy dissipation analysis it has been shown that the variation of the excess pressure drop with the flow rate is controlled by the flow-microstructure coupling in the extensional flow dominated region of the flow. Finally, the influence of the macromolecular chain extensibility on the vortex dynamics, i.e. growth of the upstream corner vortex at low chain extensibility or the shrinkage of the upstream corner vortex coupled with the formation of a lip vortex that eventually merges with the upstream corner vortex at high chain extensibility is elucidated.
Dynamics of ultra-thin two-layer films under the action of inclined temperature gradients
Authors: NEPOMNYASHCHY ALEXANDER A. , SIMANOVSKII ILYA B.
Published: July 2009

The development of instabilities under the joint action of the van der Waals forces and Marangoni stresses in a two-layer film in the presence of an inclined temperature gradient is investigated. The problem is solved by means of a linear stability theory and nonlinear simulations. It has been found that for sufficiently large values of the ratio between the longitudinal and transverse Marangoni numbers, the real part of the linear growth rate does not depend on the direction of the wavenumber, except the case of nearly longitudinal disturbances. Numerous types of nonlinear evolution have been observed, among them are ordered systems of droplets, ‘splashes’, oblique waves, modulated transverse and longitudinal structures.
Low-dimensional models and performance scaling of a highly deformable fish pectoral fin
Authors: BOZKURTTAS M. , MITTAL R. , DONG H. , LAUDER G. V. , MADDEN P.
Published: July 2009

The hydrodynamics of a highly deformable fish pectoral fin used by a bluegill sunfish (Lepomis macrochirus) during steady forward swimming are examined in detail. Low-dimensional models of the fin gait based on proper orthogonal decomposition (POD) are developed, and these are subjected to analysis using an incompressible Navier–Stokes flow solver. The approach adopted here is primarily motivated by the quest to develop insights into the fin function and associated hydrodynamics, which are specifically useful for the design of a biomimetic, pectoral fin propulsor. The POD analysis shows that the complex kinematics of the pectoral fin can be described by a few (<5) POD modes and that the first three POD modes are highly distinct. The significance of these modes for thrust production is examined by synthesizing a sequence of fin gaits from these modes and simulating the flow associated with these gaits. We also conduct a scale study of the pectoral fin in order to understand the effect of the two key non-dimensional parameters, Reynolds number and Strouhal number, on the propulsive performance. The implications of the POD analysis and performance scaling on the design of a robotic pectoral fin are discussed.
Stability of micropolar fluid flow between concentric rotating cylinders
Authors: WENG HUEI CHU , CHEN CHA'O-KUANG , CHANG MIN-HSING
Published: July 2009

In this study, the theory of micropolar fluids is employed to study the stability problem of flow between two concentric rotating cylinders. The field equations subject to no-slip conditions (non-zero velocity and microrotation velocity components) at the wall surfaces are solved. The analytical solutions of the velocity and microrotation velocity fields as well as the shear stress difference, couple stress and strain rate for basic flow are obtained. The equations with respect to non-axisymmetric disturbances are derived and solved by a direct numerical procedure. It is found that non-zero wall-surface microrotation velocity makes the flow faster and more unstable. Moreover, it tends to reduce the limits of critical non-axisymmetric disturbances. The effect on the stability characteristics can be magnified by increasing the microstructure or couple-stress parameter or the microinertia parameter for the cases of corotating cylinders and a stationary outer cylinder or by decreasing the radius ratio or the microinertia parameter for the case of counterrotating cylinders.
Particulate gravity currents along V-shaped valleys
Authors: MONAGHAN JOE J. , MÉRIEUX CATHERINE , HUPPERT HERBERT E. , MANSOUR JOHN
Published: July 2009

This paper extends previous studies of saline gravity currents at high Reynolds number flowing along a tank with a V-shaped valley. We use experiments and a box model to determine the primary features of the flow. The particulate gravity currents were initiated by releasing a fixed volume of fluid consisting of pure water mixed with silicon carbide particles from a lock at one end of the tank. The resulting motion and deposit pattern differ significantly from those for the propagation of a particulate gravity current along a flat-bottomed tank. The front of the current, seen from above, is approximately parabolic (with axis parallel to the flow direction) in contrast to the current in a flat-bottomed tank where it is nearly a straight line perpendicular to the flow. This feature mimics the results for pure saline currents. When seen in profile the currents do not have a clearly defined raised head, which is a feature of the flat-bottomed currents. The mass deposited per unit area varies nearly monotonically with respect to distance down the tank, again in contrast to the case of the flat-bottomed tank. The exceptions to this are the two experiments which have the highest ratio of lock height to length. The mass deposited per unit area across the V-shaped valley is much larger in the central part of the valley than it is on the flanks for any position along the valley. We find that the results can be described with remarkable accuracy by a box model using a generalization of the equation for sedimentation from a turbulent medium due to Martin and Nokes. Our results further show that the factor used in the deposition rate equation which is commonly assumed to be 1 should be smaller, typically 0.7.
Exact solutions for Stokes flow in and around a sphere and between concentric spheres
Authors: SHANKAR P. N.
Published: July 2009

A general method is suggested for deriving exact solutions to the Stokes equations in spherical geometries. The method is applied to derive exact solutions for a class of flows in and around a sphere or between concentric spheres, which are generated by meridional driving on the spherical boundaries. The resulting flow fields consist of toroidal eddies or pairs of counter-rotating toroidal eddies. For the concentric sphere case the exact solution when the inner sphere is in instantaneous translation is also derived. Although these solutions are axisymmetric, they can be combined with swirl about a different axis to generate fully three-dimensional fields described exactly by simple formulae. Examples of such complex fields are given. The solutions given here should be useful for, among other things, studying the mixing properties of three-dimensional flows.
Effective interaction potential of dust particles in a plasma from experimental pair correlation functions
Authors: RAMAZANOV T. S. , DZHUMAGULOVA K. N. , DANIYAROV T. T. , OMARBAKIYEVA Yu. A. , KODANOVA S. K. , DOSBOLAYEV M. K.
Published: July 2009

Interaction between dust particles in a plasma is investigated on the basis of experimental pair correlation functions of dust formation in a dc glow discharge and the Poisson equation. It is shown that the calculated effective potentials have an oscillating character and depend rather weakly on macroscopic parameters of the plasma. Existence of an attractive component in the interaction of dust particles is confirmed within the validity range of our model.
Magnetic fluctuation level in disruption plasmas in the TEXTOR tokamak
Authors: YANG X. , LIU J. , GAO T. , LI M. , SHI Y. J. , LIANG H. F. , CAI W. D. , CHEN Z. Y.
Published: July 2009

Runaway transport is used to probe the magnetic fluctuation level for TEXTOR disruption plasmas. A zero-dimensional model of the current quench including the generation of runaway electrons has been applied to simulate the experimental current evolution during major disruptions [Plasma Phys. Control. Fusion50 (2008), 105007]. According to the loss rate of runaway electrons used in the fitting parameter of the zero-dimensional model, the magnetic fluctuation level in TEXTOR is derived. It is found that the magnetic fluctuation level is in the order of 10−5, and it increases with the atom number mixed into the plasma.
The association of visuospatial working memory with dysthymic disorder in pre-pubertal children
Authors: Franklin T. , Lee A. , Hall N. , Hetrick S. , Ong J. , Haslam N. , Karsz F. , Vance A.
Published: July 2009

Background

Visuospatial working memory (VSWM) deficits have not been investigated specifically in children with dysthymic disorder (DD), although they are associated with impairments in attention that commonly occur in DD. This study investigates VSWM impairment in children with DD.

Method

A cross-sectional study of VSWM in 6- to 12-year-old children with medication-naive DD (n=26) compared to an age-, gender- and ‘performance IQ’ (PIQ)-matched healthy control group (n=28) was completed.

Results

The DD group demonstrated impairment in VSWM, including impairment in the spatial span and strategy components of VSWM. Furthermore, the VSWM impairment remained after controlling for spatial span. Inattentive symptoms were significantly associated with the VSWM impairment.

Conclusions

This study of children with DD found deficits in performance on VSWM tasks, suggesting that fronto-striatal–parietal neural networks that underlie processes of attention and the executive component of VSWM are dysfunctional in children with DD. These findings further our understanding of DD and suggest more specific interventions that might improve functioning.
Approach and avoidance learning in patients with major depression and healthy controls: relation to anhedonia
Authors: Chase H. W. , Frank M. J. , Michael A. , Bullmore E. T. , Sahakian B. J. , Robbins T. W.
Published: July 2009

Background

Central to understanding of the behavioural consequences of depression has been the theory that the disorder is accompanied by an increased sensitivity to negative compared with positive reinforcement (negative bias), whereas other theorists have emphasized a global reduction in sensitivity to reinforcement in depression (blunting).

Method

In this study, we used a probabilistic selection task that was designed to examine independently rates of learning to predict both positive and negative reinforcement. Twenty-three depressed out-patients and 23 healthy controls from the local population participated in the study.

Results

No evidence for a negative bias was observed on the task, either during acquisition of the task or during generalization of the learned information. Depressed patients responded slower on the task than controls but showed a similar modulation of reaction times (RTs) as controls following reinforcement. Evidence for blunting was observed on the training phase, as reflected in reduced trial-by-trial adjustment during this phase. However, this effect was related specifically to the severity of anhedonia, as measured by the Snaith–Hamilton Pleasure Scale (SHAPS), and was independent of overall depression severity.

Conclusions

We argue that the observation of a negative bias or blunting in a group of depressed patients may be dependent on the neuropsychological task and the symptoms of the patients tested. Our results provide insight into how these theories might be further tested.
Degenerate random perturbations of Anosov diffeomorphisms
Authors: YARMOLA TATIANA
Published: July 2009

This paper deals with random perturbations of diffeomorphisms on n-dimensional Riemannian manifolds with distributions supported on k-dimensional disks, where k<n. First we demonstrate general but not very intuitive conditions which guarantee that all invariant measures for rank-k random perturbations of C2 diffeomorphisms are absolutely continuous with respect to the Riemannian measure on M. For two subclasses of Anosov diffeomorphisms, hyperbolic toral automorphisms and Anosov diffeomorphisms with codimension 1 stable manifolds, the above conditions are modified in order to relate k-dimensional disks that support the distributions to certain foliations that arise from Anosov diffeomorphisms. We conclude that generic rank-k random perturbations have absolutely continuous invariant measures.
Livšic theorems for non-commutative groups including diffeomorphism groups and results on the existence of conformal structures for Anosov systems
Authors: DE LA LLAVE RAFAEL , WINDSOR ALISTAIR
Published: July 2009

The celebrated Livšic theorem [A. N. Livšic, Certain properties of the homology ofY-systems,Mat. Zametki 10(1971), 555–564; A. N. Livšic, Cohomology of dynamical systems,Izv. Akad. Nauk SSSR Ser. Mat. 36(1972), 1296–1320] states that given a manifoldM, a Lie groupG, a transitive Anosov diffeomorphismfonMand a Hölder functionη:M↦Gwhose range is sufficiently close to the identity, it is sufficient for the existence of ϕ:M↦Gsatisfyingη(x)=ϕ(f(x))ϕ(x)−1that a condition—obviously necessary—on the cocycle generated byηrestricted to periodic orbits is satisfied. In this paper we present a new proof of the main result. These methods allow us to treat cocycles taking values in the group of diffeomorphisms of a compact manifold. This has applications to rigidity theory. The localization procedure we develop can be applied to obtain some new results on the existence of conformal structures for Anosov systems.
A renormalization group approach to quasiperiodic motion with Brjuno frequencies
Authors: KOCH HANS , KOCIĆ SAŠA
Published: July 2009

We introduce a renormalization group scheme that applies to vector fields on 𝕋d×ℝm with frequency vectors that satisfy a Brjuno condition. Earlier approaches were restricted to Diophantine frequencies, owing to a limited control of multidimensional continued fractions. We get around this restriction by avoiding the use of a continued-fractions expansion. Our results concerning invariant tori generalize those of [H. Koch and S. Kocić, Renormalization of vector fields and Diophantine invariant tori. Ergod. Th. & Dynam. Sys.28 (2008), 1559–1585] from Diophantine- to Brjuno-type frequency vectors. In particular, each Brjuno vector ω∈ℝd determines an analytic manifold 𝒲 of infinitely renormalizable vector fields, and each vector field on 𝒲 is shown to have an elliptic invariant d-torus with frequencies ω1,ω2,…,ωd.
Symbolic images and invariant measures of dynamical systems
Authors: OSIPENKO GEORGE
Published: July 2009

Let f be a homeomorphism of a compact manifold M. The Krylov–Bogoloubov theorem guarantees the existence of a measure that is invariant with respect to f. The set of all invariant measures ℳ(f) is convex and compact in the weak topology. The goal of this paper is to construct the set ℳ(f). To obtain an approximation of ℳ(f), we use the symbolic image with respect to a partition C={M(1),M(2),…,M(n)} of M. A symbolic image G is a directed graph such that a vertex i corresponds to the cell M(i) and an edge i→j exists if and only if f(M(i))∩M(j)≠0̸. This approach lets us apply the coding of orbits and symbolic dynamics to arbitrary dynamical systems. A flow on the symbolic image is a probability distribution on the edges which satisfies Kirchhoff’s law at each vertex, i.e. the incoming flow equals the outgoing one. Such a distribution is an approximation to some invariant measure. The set of flows on the symbolic image G forms a convex polyhedron ℳ(G) which is an approximation to the set of invariant measures ℳ(f). By considering a sequence of subdivisions of the partitions, one gets sequence of symbolic images Gk and corresponding approximations ℳ(Gk) which tend to ℳ(f) as the diameter of the cells goes to zero. If the flows mk on each Gk are chosen in a special manner, then the sequence {mk} converges to some invariant measure. Every invariant measure can be obtained by this method. Applications and numerical examples are given.
Intense heavy ion beams as a pumping source for short wavelength lasers
Authors: Adonin A. , Turtikov V. , Ulrich A. , Jacoby J. , Hoffmann D.H.H. , Wieser J.
Published: July 2009

The high energy loss of heavy ions in matter as well as the small angular scattering makes heavy ion beams an excellent tool to produce almost cylindrical and homogeneously excited volumes in matter. This aspect can be used to pump short wavelength lasers. For the first time, a beam of heavy ions was used to pump a short wavelength gas laser in an experiment performed at the GSI ion accelerator facility in December 2005. In this experiment, the well-known KrF* excimer laser was pumped with an intense uranium beam. Pulses of an uranium beam compressed down to 110 ns (full width at half maximum) with initial particle energy of 250 MeV per nucleon were stopped inside a gas laser cell. A mixture of an excimer laser premix gas (95.5%Kr + 0.5%F2) and a buffer gas (Ar) in different proportions was used as the laser gas. The maximum beam intensity reached in the experiment was 2.5 × 109particles per pulse, which resulted in 34 J/g specific energy deposited in the laser gas. The laser effect on the transition at λ = 248 nm has been successfully demonstrated by various independent methods. There, the laser threshold was reached with a beam intensity of 1.2 × 109particles per pulse, and the energy of the laser pulse of about 2 mJ was measured for an ion beam intensity of 2 × 109particles per pulse. As a next step, it is planned to reduce the laser wavelength down to the vacuum ultraviolet spectral region, and to proceed to the excimer lasers of the pure rare gases. The perspectives for such experiments are discussed and the detailed estimations for Xe and Kr cases are given. We believe that the use of heavy ion beams as a pumping source may lead to new pumping schemes on the higher lying level transitions and considerably shorter wavelengths, which rely on the high cross sections for multiple ionization of the target species.
Generation of strong magnetic fields from laser interaction with two-layer targets
Authors: Wu S.Z. , Zhou C.T. , He X.T. , Zhu S.-P.
Published: July 2009

A two-layer target irradiated by an intense laser to generate strong interface magnetic field is proposed. The mechanism is analyzed through a simply physical model and investigated by two-dimensional particle-in-cell simulation. The effect of laser intensity on the resulting magnetic field strength is also studied. It is found that the magnetic field can reach up to several ten megagauss for laser intensity at 1019 Wcm−2.
Quasi-monoenergetic proton beam generation from a double-layer solid target using an intense circularly polarized laser
Authors: Bin J.H. , Lei A.L. , Yang X.Q. , Huang L.G. , Yu M.Y. , Yu Wei , Tanaka K.A.
Published: July 2009

Monoenegetic ion beam generation from circularly polarized laser-pulse interaction with a double-layer target is considered. The front layer consists of heavy-ion plasma, and the rear layer is a small thin coating of light-ion plasma. Particle-in-cell simulation shows that the multi-dimensional effects in the ion radiation pressure acceleration are avoided and a highly monoenergetic light-ion beam can be produced. Our simulations reveal that the charge-mass ratio of heavy ions in the front layer and the thicknesses of both layers can strongly affect the proton energy spectra.
Layer structure, plasma jet, and thermal dynamics of Cu target irradiated by relativistic pulsed electron beam
Authors: Li Limin , Liu Lie , Cheng Guoxin , Xu Qifu , Ge Xingjun , Wen Jianchun
Published: July 2009

This paper, based on a relativistic electron-beam accelerator with inductive energy accumulation, investigates the layer structure, plasma jet, and thermal dynamics of Cu target under the irradiation of pulsed electron beam (~350 kV, ~4 kA, ~300 ns). A description of a relativistic electron beam source with a carbon fiber cathode is presented. After the electron-beam irradiation at ~13 J/cm2energy density, microcraters with 0.5–1 µm diameter appeared on the target surface, and the target cross section is characterized by multilayer structures with a ~20 µm thickness melting layer and a cellular layer. Further, it was found that the carbon content increased significantly not only on the target surface but also on the cross section. The gas liberation per pulse induced by electron beam is analyzed. A good agreement between the experimental and calculated perveances was observed, with the exception at the end of the accelerating pulse possibly due to the participation of ion flow from the anode target. In the pulsed emission, there existed material transfer from anode to cathode, which is observed by the identification of elemental compositions on cathode surface. As the beam energy is deposited on target surface, the anode plasma jet is generated, and expands toward the cathode at a velocity of ~3 cm/μs. By solving the one-dimensional heat equation, 109K/s heating rate and 107K/m temperature gradient can be obtained. After the heating of pulsed electron beam, the thermal conduction is dominant, with a cooling rate on the order of 107 K/s. The relativistic electron beam sources may provide a potential development for target experiments and high energy density physics.
Ultrashort laser subsurface micromachining of three–dimensional microfluidic structures inside photosensitive glass
Authors: Wang Z. , Zheng H. , Zhou W.
Published: July 2009

A laser direct writing technique was used successfully to carry out subsurface micromachining of three-dimensional microfluidic structures. It involves simple steps of femtosecond laser irradiation to project a latent image of channels or chambers of various dimensions into a photosensitive Foturan glass, thermal annealing to produce crystallites of lithium metasilicates in the laser-irradiated regions, and use of a diluted hydrofluoric acid solution to remove the crystallized structures through selective chemical etching. The etched surfaces may be smoothened significantly through a secondary thermal annealing process. A microfluidic reagent mixer and reactor consisting of four cubic chambers and multiple channels was produced inside a single piece of glass to demonstrate that the technique can be used for rapid device fabrication without recourse to the cumbersome and expensive processes of alignment, stacking, bonding or assembly of the individual microcomponents. The direct writing technique makes it easy to integrate micro–optical and microfluidic components into a single chip.
An approach to quantifying Pliocene ice sheet dynamics via slope failure frequencies recorded in Antarctic Peninsula rise sediments
Authors: Hepp Daniel A. , Mörz Tobias
Published: July 2009

Understanding of glacially driven sedimentary transport systems across the shelf to the slope and subsequently to deep sea sediment bodies along the Pacific continental margin of Antarctic Peninsula is crucial for interpreting ice sheet dynamics. Here we quantify slope-failure frequencies recorded in Pliocene core intervals of ODP Site 1095. We used the relationship between long-term sedimentation rate and marine carbon burial efficiency to calculate glacial or interglacial specific sedimentation rates. Using the decompacted average length of glacial-interglacial cycles it was possible to solve a set of linear equations to derive average half-periods of 61.59 and 59.77 kyr respectively for the time interval 5.8–3.2 Ma. The resulting frequency distribution of slope failures reflects short and rapid but cyclic ice advances every ∼375 years. Short retention times between slope loading and slope failure are supported by biogenic silica dissolution analyses. This study demonstrates the potential of the rise record to improve models of orbitally controlled size variations of the West Antarctic ice sheet and confirms the hypothesis of a highly dynamic ice sheet during the early Pliocene warm period.
Infant weight gain, duration of exclusive breast-feeding and childhood BMI – two similar follow-up cohorts
Authors: Gunnarsdottir Ingibjorg , Schack-Nielsen Lene , Michaelsen Kim Fleischer , Sørensen Thorkild IA , Thorsdottir Inga
Published: July 2009

Objective

To describe the association between duration of exclusive breast-feeding (EBF), weight gain in infancy and childhood BMI in two populations with a long duration of EBF.

Design

Cohort study with follow-up in childhood. Breast-feeding status was reported monthly during infancy. Weight and length were measured at birth, 2, 6 and 12 months of age, as well as in childhood at 6 or 10 years of age.

Setting

Iceland and Denmark.

Subjects

Randomly selected healthy newborns from Denmark (n85) and Iceland (n100).

Results

Infants exclusively breast-fed for ≤2 months gained 348 (95% CI 69, 626) g more weight from 2 to 6 months than infants exclusively breast-fed for 3–4 months (P= 0·009). Weight gain from 6 to 12 months was found to be greater among infants exclusively breast-fed for ≤2 months compared with those exclusively breast-fed for ≥5 months (P= 0·008). A greater weight change, in terms ofZ-score, between the ages of 2 and 6 months was associated with higherZ-score of childhood BMI, adjusted for birth weight, country and duration of EBF (B= 0·49,se= 0·11,P< 0·001, adj.R2= 0·15). However, the association was much stronger in the Icelandic cohort than the Danish one.

Conclusions

Although duration of EBF was not associated with childhood BMI in the present study it may modulate growth rate in infancy, which is related to childhood BMI. However, other factors determinative for infant growth also need to be considered when assessing the relationship of early growth and nutrition to childhood overweight, as traditions in complementary food might differ between populations.
Evaluation of the Missouri WIC (Special Supplemental Nutrition Program for Women, Infants, and Children) breast-feeding peer counselling programme
Authors: Yun Shumei , Liu Qian , Mertzlufft Kathy , Kruse Catherine , White Maggie , Fuller Phyllis , Zhu Bao-Ping
Published: July 2009

Objective

To evaluate the effectiveness of the peer counselling (PC) programme on breast-feeding initiation among participants in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) in Missouri, and to identify factors that facilitate breast-feeding initiation.

Design

We used the data from the 2006 Missouri Pregnancy Nutrition Surveillance System, Missouri Live Birth Records and the Missouri WIC programme to compare breast-feeding initiation rates between PC and non-PC agencies. We used multilevel logistic regression, with individual participants being nested within agencies, to control for individual- and agency-level characteristics.

Results

The breast-feeding initiation rate in PC agencies was significantly higher than in non-PC agencies among prenatal participants, but the difference was not significant among postpartum participants. After controlling for maternal sociodemographic characteristics, compared with prenatal cases in non-PC agencies, prenatal cases in PC agencies were more likely to initiate breast-feeding (OR = 1·21; 95 % CI 1·03, 1·43), whereas postpartum cases were less likely to initiate breast-feeding. Among prenatal participants in PC agencies, longer duration of prenatal WIC enrolment was associated with a higher rate of breast-feeding initiation. After adjusting for maternal sociodemographic characteristics and other agency-level characteristics, participants of PC agencies with an international board-certified lactation consultant were more likely to initiate breast-feeding than participants of PC agencies without such a consultant (OR = 1·21; 95 % CI 1·01, 1·45).

Conclusions

Prenatal participation in the WIC breast-feeding PC programme (especially participation early during pregnancy) was associated with an increased rate of breast-feeding initiation in Missouri.
Contribution of specific dietary factors to CHD in US females
Authors: Tran Nga , Barraj Leila
Published: July 2009

Objective

To estimate dietary cholesterol contribution to CHD risk among US females, relative to other dietary risk factors.

Design

A risk apportionment model was applied to apportion CHD risk shares among the lifestyle and dietary risk factors.

Setting

The model was implemented using relative risks from the Nurses’ Health Study and data on CHD risk factors and consumption from the National Health and Nutrition Examination Survey 1999–2002.

Subjects

US females aged 25 years or older.

Results

On average, poor diet contributes 20 % of the CHD risk relative to obesity, inactivity and smoking, of which trans fat intake contributes 2·9 %, dietary cholesterol 1·5 % and 16 % is due to low consumption of nutrients, i.e. MUFA (1·5 %), PUFA (1·7 %), marine n-3 fatty acids (2·7 %), α-linolenic acid (1·1 %), dietary fibre (2·4 %), vitamin B6 (4·1 %), vitamin C (0·5 %) and folate (1·8 %).

Conclusions

Reducing trans fat and dietary cholesterol intakes could lead to CHD reduction, but greater risk reduction may be achieved by improving intakes of heart-healthy nutrients currently deficient in US females’ diets. Total diet consideration is essential in any CHD risk reduction strategy.
TEMPERATURE MODULATION IN RAYLEIGH–BÉNARD CONVECTION
Authors: SINGH JITENDER , BAJAJ RENU
Published: July 2009

The stability characteristics of an infinite horizontal fluid layer excited by a time-periodic, sinusoidally varying free-boundary temperature, have been investigated numerically using the Floquet theory. It has been found that the modulation of the temperature gradient across the fluid layer affects the onset of the Rayleigh–Bénard convection. Modulation can give rise to instability in the subcritical conditions and it can also suppress the instability in the supercritical cases. The instability in the fluid layer manifests itself in the form of either a harmonic or subharmonic flow, controlled by thermal modulation.
SPACE–TIME STRUCTURE AND SPINOR GEOMETRY
Authors: SZEKERES GEORGE , PETERS LINDSAY
Published: July 2009

The structure of space–time is examined by extending the standard Lorentz connection group to its complex covering group, operating on a 16-dimensional “spinor” frame. A Hamiltonian variation principle is used to derive the field equations for the spinor connection. The result is a complete set of field equations which allow the sources of the gravitational and electromagnetic fields, and the intrinsic spin of a particle, to appear as a manifestation of the space–time structure. A cosmological solution and a simple particle solution are examined. Further extensions to the connection group are proposed.
Liquid water and organics in Comets: implications for exobiology
Authors: Wickramasinghe J.T. , Wickramasinghe N.C. , Wallis M.K.
Published: July 2009

Liquid water in comets, once considered impossible, now appears to be almost certain. New evidence has come from the discovery of clay minerals in comet Tempel 1, which compliments the indirect evidence in aqueous alteration of carbonaceous chondrites. Infrared spectral indication of clay is confirmed by modelling data in the 8–40 μm and 8–12 μm wavebands on the basis of mixtures of clays and organics. Radiogenic heating producing liquid water cores in freshly formed comets appears more likely on current evidence for solar system formation. A second possibility investigated here is transient melting in comets in the inner solar system, where thin crusts of asphalt-like material, formed due to solar processing and becoming hot in the daytime, can cause melting of sub-surface icy material a few centimetres deep. Supposing comets were seeded with microbes at the time of their formation from pre-solar material, there would be plenty of time for exponential amplification and evolution within the liquid interior and in the transient ponds or lakes formed as the outer layers are stripped away via sublimation.
SSR marker-based DNA fingerprinting and cultivar identification of rice (Oryza sativa L.) in Punjab state of India
Authors: Sarao Navraj K. , Vikal Yogesh , Singh Kuldeep , Joshi Monika A. , Sharma R. C.
Published: July 2009

In India, Protection of Plant Varieties and Farmer's Rights Act (PPV&FRA, 2001) requires the registration and protection of new and notified/extant plant varieties based on the criteria of distinctness, uniformity and stability (DUS) of morphological characteristics. However, these morphological traits have not been able to resolve closely related genotypes. The molecular markers can very well support the DUS testing in such cases. In the present study, therefore, 14 varieties of rice cultivated in Punjab state of India were fingerprinted using 75 simple sequence repeat (SSR) primers. Out of these, 58 primers produced polymorphic profiles, while 13 were monomorphic, 2 revealed null allele and the remaining 2 amplified only from super basmati. In a screen of 7 cultivars, 16 SSR loci produced 17 rare/unique alleles, which provided an opportunity for their unambiguous identification. Cluster analysis based on SSR data clearly distinguished the cultivars into two dist inct groups: comprising non-basmati (group I) and basmati (group II). The cluster pattern was consistent with the pedigree and breeding history of the cultivars.
The Power Politics of Regime Complexity: Human Rights Trade Conditionality in Europe
Authors: Hafner-Burton Emilie M.
Published: July 2009

This article argues that international regime complexity has shaped Europe's politics of human rights trade conditionality by creating opportunities for various types of “forum shopping,” and, consequently, that some of the most significant politics of human rights enforcement have occurred in an entirely separate issue area—trade—which are being worked out partly during lawmaking and partly during implementation. The presence of nested and overlapping institutions creates incentives for rival political actors—whether states, institutions, or policymakers—to (1) forum shop for more power, (2) advantage themselves in the context of a parallel or overlapping regime, and (3) invoke institutions á la carte to govern a specific issue but not others. Each tactic creates competition between institutions and actors for authority over the rules, setting hurdles for IO performance. Even so, (4) regime complexity can make enforcement of rules that are impossible to implement in one area possible in another area.
Aufmerksamkeitsdefizit-/Hyperaktivitätsstörung (ADHS)
Authors: Petermann Franz , Hampel Petra
Published: July 2009

Bei ADHS liegt eine lebenslange psychische Erkrankung vor, die durch multimodale Vorgehensweisen erfolgreich zu behandeln ist. Entwicklungs- und neuropsychologische Grundlagen besitzen vor allem im Bereich der Ursachendiskussion und psychologischen Diagnostik eine große Bedeutung.
Die Verarbeitung von Negationen bei Kindern mit ADHS und der Einfluss medikamentöser Behandlung
Authors: Schmiedeler Sandra , Schwenck Christina , Schneider Wolfgang
Published: July 2009

Personen verarbeiten Negationen (z. B. „Tom ist nicht alt“) dann fehlerhaft, wenn nicht ausreichend kognitive Ressourcen verfügbar sind. Wir nehmen an, dass diese kognitive Kapazität von Kindern mit einer Aufmerksamkeitsdefizit- und Hyperaktivitätsstörung (ADHS) besonderer Einschränkung unterliegt, die sich in einer defizitären Negationsverarbeitung äußern sollte. Untersucht wurden 25 Jungen mit ADHS (8 – 14 Jahre) einmal ohne und ein weiteres Mal unter Methylphenidatmedikation in ausbalancierter Reihenfolge sowie 32 klinisch unauffällige Jungen. Zur Erfassung der Negationsverarbeitung wurde ein an Deutsch, Gawronski und Strack (2006) angelehntes Reaktionszeitexperiment verwendet. Die Patienten ohne Medikation wiesen im Vergleich zu den gesunden Kontrollen eine bedeutsam erhöhte Fehleranfälligkeit auf. Sie zeigten jedoch keine Beeinträchtigungen in spezifischen Prozessen der Negationsverarbeitung. Ein signifikanter Effekt der Methylphenidatbehandlung auf die Arbeitsgenauigkeit und -konstanz wurde belegt. Alter und Arbeitsgedächtnis beeinflussten die Informationsverarbeitungsleistung. Die Annahme einer defizitären Negationsverarbeitung bei Kindern mit ADHS konnte nicht bestätigt werden.