Some size relationships in phytoflagellate motility

Data from the literature are used to assess some hypothesised adaptive advantages of the flagellate life form among phytoplankton. Possible advantages include increased nutrient uptake by movement through a homogeneous medium as opposed to exploitation of spatial hetrogeneity of the environment. Maximal migrational amplitudes and maximal swimming velocities of phytoflagellates were compared to body size. Both were found to increase with size. Relative amplitudes and relative velocities, however, were found to decrease with size. Hydrophysical considerations show that additional gain of nutrients by swimming through a homogeneous medium is only minimal for small flagellates at their attainable swimming velocities. It is suggested that exploitation of environmental heterogeneity in nutrient distribution may be one of the most important advantages for flagellates over coccoid algae

Inclusive Jet and Hadron Suppression in a Multi-Stage Approach

We present a new study of jet interactions in the Quark-Gluon Plasma created in high-energy heavy-ion collisions, using a multi-stage event generator within the JETSCAPE framework. We focus on medium-induced modifications in the rate of inclusive jets and high transverse momentum (high-$p_{\mathrm{T}}$) hadrons. Scattering-induced jet energy loss is calculated in two stages: A high virtuality stage based on the MATTER model, in which scattering of highly virtual partons modifies the vacuum radiation pattern, and a second stage at lower jet virtuality based on the LBT model, in which leading partons gain and lose virtuality by scattering and radiation. Coherence effects that reduce the medium-induced emission rate in the MATTER phase are also included. The \trento\ model is used for initial conditions, and the (2+1)D VISHNU model is used for viscous hydrodynamic evolution. Jet interactions with the medium are modeled via 2-to-2 scattering with Debye screened potentials, in which the recoiling partons are tracked, hadronized, and included in the jet clustering. Holes left in the medium are also tracked and subtracted to conserve transverse momentum. Calculations of the nuclear modification factor ($R_{\mathrm{AA}}$) for inclusive jets and high-$p_{\mathrm{T}}$ hadrons are compared to experimental measurements at RHIC and the LHC. Within this framework, we find that two parameters for energy-loss, the coupling in the medium and the transition scale between the stages of jet modification, suffice to successfully describe these data at all energies, for central and semi-central collisions, without re-scaling the jet transport coefficient $\hat{q}$.Comment: 33 pages, 23 figure

Multi-scale evolution of charmed particles in a nuclear medium

Parton energy-momentum exchange with the quark gluon plasma (QGP) is a multi-scale problem. In this work, we calculate the interaction of charm quarks with the QGP within the higher twist formalism at high virtuality and high energy using the MATTER model, while the low virtuality and high energy portion is treated via a (linearized) Boltzmann Transport (LBT) formalism. Coherence effect that reduces the medium-induced emission rate in the MATTER model is also taken into account. The interplay between these two formalisms is studied in detail and used to produce a good description of the D-meson and charged hadron nuclear modification factor RAA across multiple centralities. All calculations were carried out utilizing the JETSCAPE framework

Psychische Störungen und Behandlungsbedarf junger Frauen in Dresden

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Modelling algal productivity and oxygen production in large outdoor cultures

A deterministic mathematical model was used to describe the production of green microalgae (Scenedesmus obiiquus, Coelastrum sphaericum) in outdoor mass cultures. The model was calibrated against sixteen months of temperature and irradiance measurements, during which time productivity measurements were made in up to five ponds with surface areas of up to 263 m$^{2}$. During this period raten of algal dry matter production varied between 1.7 and 16.92 g m$^{-2} d^{-1}$ The model yielded an average productivity of 5.5 g m$^{-2} d^{-1}$ for the saure period. Negative productivity values (loss af biomass) were determined for the months November, December and January and showed that meaningful production would only he possible für seven months per year in the temperate areas of Europe. Several assumptions had to be made, concerning especially the lass Factors such as respiration, release cf DOC and photo-inhibition. The latter was included as a separate factor in the model and is merely conceptual. The described model showed good agreement with the field observations. lt was consequently used to determine the influence of temperature and irradiance an productivity, the relation hetween areal density and productivity and the oxygen production potential for use in "photosynthetic" wastewater treatment systems. A description of the model and its various constants and variables are provided. A printout of the entire program is given as an appendix

Erfahrungen und Lehren des Kampfes der Arbeiterklasse fuer die Stabilitaet der Diktatur des Proletariats

DB Leipzig(101) - Di 1983 B VD 126, T. 1, 2 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Zum Behandlungsbedarf bei psychischen Störungen junger Frauen

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