Groei en begrazing van mosselzaad, primaire productie en picoplankton in de Waddenzee: Technisch Rapport project Meerjarig effect- en productiemetingen aan MZI's in de Westerlijke Waddenzee, Oosterschelde en Voordelta

In het kader van het project: “Meerjarige effectmetingen aan MZI’s in de Westelijke Waddenzee en de Oosterschelde”, uitgevoerd door IMARES in opdracht van het Ministerie van LNV (thans EZ), zijn er in 2010 tot en met 2013 veldmetingen verricht bij een MZI. Centrale vraag binnen deelproject 1 betreft de mogelijke invloed van MZI’s op de draagkracht van de Waddenzee en de Oosterschelde. In dit rapport worden de resultaten gepresenteerd van het onderzoek aan de MZI’s in de Waddenzee

Strategic toolkits: seniority, usage and performance in the German SME machinery and equipment sector

This paper examines the strategic tool kit, from a human resource management (HRM) perspective, in terms of usage and impact. Research to date has tended to consider usage, assuming to a certain extent that knowledge and understanding of particular tools suggest that practitioners value them. The research on which this paper is based builds upon the idea that usage indicates satisfaction, but develops the usage theme to investigate which decision-makers are actually engaged in both tool appliance and the strategic process. Of particular interest to the researchers are the educational background, age and seniority of the decision-makers. In addition, potential links with HRM and organizational performance are also explored. The context of the research, the German machinery and equipment sector, provides an insight into the industry's ability to sustain growth in face of increasing international competition. The paper calls for a greater awareness, from a human resource perspective, and utilization of strategic management practice and associated decision-making aids

Comparison of two non-primitive methods for path integral simulations: Higher-order corrections vs. an effective propagator approach

Two methods are compared that are used in path integral simulations. Both methods aim to achieve faster convergence to the quantum limit than the so-called primitive algorithm (PA). One method, originally proposed by Takahashi and Imada, is based on a higher-order approximation (HOA) of the quantum mechanical density operator. The other method is based upon an effective propagator (EPr). This propagator is constructed such that it produces correctly one and two-particle imaginary time correlation functions in the limit of small densities even for finite Trotter numbers P. We discuss the conceptual differences between both methods and compare the convergence rate of both approaches. While the HOA method converges faster than the EPr approach, EPr gives surprisingly good estimates of thermal quantities already for P = 1. Despite a significant improvement with respect to PA, neither HOA nor EPr overcomes the need to increase P linearly with inverse temperature. We also derive the proper estimator for radial distribution functions for HOA based path integral simulations.Comment: 17 pages, latex, 6 postscript figure

An improved quantitative measure of the tendency for volcanic ash plumes to form in water: implications for the deposition of marine ash beds

Laboratory experiments and numerical simulations have shown that volcanic ash particles immersed in water can either settle slowly and individually, or rapidly and collectively as particle-laden plumes. The ratio of timescales for individual and collective settling, in the form of analytical expressions, provides a dimensionless quantitative measure of the tendency for such plumes to grow and persist which has important implications for determining particle residence times and deposition rates. However, existing measures in the literature assume that collective settling obeys Stokes' law and is therefore controlled by the balance between gravitational forces and viscous drag, despite plume development actually being controlled by the balance between gravitational forces and inertial drag even in the absence of turbulence during early times. This paper presents a new measure for plume onset which takes into account the inertial drag-controlled (rather than viscous drag-controlled) nature of plume growth and descent. A parameter study comprising a set of numerical simulations of small-scale volcanic ash particle settling experiments highlights the effectiveness of the new measure and, by comparison with an existing measure in the literature, also demonstrates that the timescale of collective settling is grossly under-estimated when assuming that plume development is slowed by viscous drag. Furthermore, the formulation of the new measure means that the tendency for plumes to form can be estimated from the thickness and concentration of the final deposit; the magnitude and duration of particle flux across the water's surface do not need to be known. The measure therefore permits the residence times of particles in a large body of water to be more accurately and practically determined, and allows the improved interpretation of layers of volcaniclastic material deposited at the seabed

Plane-symmetric inhomogeneous magnetized viscous fluid universe with a variable Λ\Lambda

The behavior of magnetic field in plane symmetric inhomogeneous cosmological models for bulk viscous distribution is investigated. The coefficient of bulk viscosity is assumed to be a power function of mass density $(\xi =\xi_{0}\rho^{n})$. The values of cosmological constant for these models are found to be small and positive which are supported by the results from recent supernovae Ia observations. Some physical and geometric aspects of the models are also discussed.Comment: 18 pages, LaTex, no figur

Neandertal and Denisovan DNA from Pleistocene sediments.

Although a rich record of Pleistocene human-associated archaeological assemblages exists, the scarcity of hominin fossils often impedes the understanding of which hominins occupied a site. Using targeted enrichment of mitochondrial DNA we show that cave sediments represent a rich source of ancient mammalian DNA that often includes traces of hominin DNA, even at sites and in layers where no hominin remains have been discovered. By automation-assisted screening of numerous sediment samples we detect Neandertal DNA in eight archaeological layers from four caves in Eurasia. In Denisova Cave we retrieved Denisovan DNA in a Middle Pleistocene layer near the bottom of the stratigraphy. Our work opens the possibility to detect the presence of hominin groups at sites and in areas where no skeletal remains are found

Status of an Investigation of the 3-He Wave Function by Quasi-Free Scattering

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Longitudinal double-spin asymmetry and cross section for inclusive neutral pion production at midrapidity in polarized proton collisions at sqrt(s) = 200 GeV

We report a measurement of the longitudinal double-spin asymmetry A_LL and the differential cross section for inclusive Pi0 production at midrapidity in polarized proton collisions at sqrt(s) = 200 GeV. The cross section was measured over a transverse momentum range of 1 < p_T < 17 GeV/c and found to be in good agreement with a next-to-leading order perturbative QCD calculation. The longitudinal double-spin asymmetry was measured in the range of 3.7 < p_T < 11 GeV/c and excludes a maximal positive gluon polarization in the proton. The mean transverse momentum fraction of Pi0's in their parent jets was found to be around 0.7 for electromagnetically triggered events.Comment: 6 pages, 3 figures, submitted to Phys. Rev. D (RC

High pTp_{T} non-photonic electron production in pp+pp collisions at s\sqrt{s} = 200 GeV

We present the measurement of non-photonic electron production at high transverse momentum ($p_T >$ 2.5 GeV/$c$) in $p$ + $p$ collisions at $\sqrt{s}$ = 200 GeV using data recorded during 2005 and 2008 by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The measured cross-sections from the two runs are consistent with each other despite a large difference in photonic background levels due to different detector configurations. We compare the measured non-photonic electron cross-sections with previously published RHIC data and pQCD calculations. Using the relative contributions of B and D mesons to non-photonic electrons, we determine the integrated cross sections of electrons ($\frac{e^++e^-}{2}$) at 3 GeV/$c < p_T <~$10 GeV/$c$ from bottom and charm meson decays to be ${d\sigma_{(B\to e)+(B\to D \to e)} \over dy_e}|_{y_e=0}$ = 4.0$\pm0.5$({\rm stat.})$\pm1.1$({\rm syst.}) nb and ${d\sigma_{D\to e} \over dy_e}|_{y_e=0}$ = 6.2$\pm0.7$({\rm stat.})$\pm1.5$({\rm syst.}) nb, respectively.Comment: 17 pages, 17 figure