Wind Mixing in Temperature Simulations for Lakes and Reservoirs

A one-dimensional mathematical formulation for simulating the wind mixing of the surface layers in reservoirs and lakes is developed. Emphasis is placed on the estimation of the net available wind-supplied energy for mixing by taking into consideration the variability of the wind in time. The formulation of the dynamics of the wind-mixed layer presented in this paper is implemented in a modified version of the one-dimensional Massachusetts Institute of Technology reservoir model. The model was used to predict the annual cycle of the thermal structure of Spada Lake in northwestern Washington State. A complete record of inflow and outflow water temperatures, temperature profiles in the reservoir, and meteorological data at the site over a 16-month period provided the basis for verifying the model. Special effort was made to screen and analyze these data to assure their quality. The application of the temperature model in Spada Lake produced good agreement between simulated and observed temperature profiles. Noticeable features of this application are the accurate simulation of the growth of the wind-mixed layer in the fall and the prediction of the exact time of formation and melting of the ice cover in the winter. These features could not have been predicted accurately without accounting for the variability of the wind pattern and its effect on the net available energy for mixing, as it was found in earlier simulations with simpler formulations of the wind-mixing effect.     

Determination of proximate composition,fatty acid content and amino acid profile of five lesser‐common sea organisms from the Mediterranean Sea

Proximate composition, fatty acid and amino acid analysis of an echinoderm (Paracentrotus lividus), a crustacean (Penaeus kerathurus), a tunicate (Microcosmus sulcatus), and two gastropod molluscs (Littorina littorea and Patella coerulea) were determined. All organisms except M. sulcatus, were found to be good protein sources. P. lividus contained on average 15.1 g/100 g, P. kerathurus 15.6 g/100 g, L. littorea 8.3 g/100 g and P. coerulea 9.2 g/100 g protein. The crustacean contained high percentages of n‐3 fatty acids (28.3 g/100 g fatty acids), the tunicate high percentages of saturated fatty acids (62.2 g/100 g fatty acids) while the gastropod molluscs and the echinoderm had a balanced content of all fatty acid families. The most abundant amino acid in P. kerathurus, M. sulcatus, L. littorea and P. coerulea was glutamic acid (11.13 ± 0.9, 1.05 ± 0.3, 5.39 ± 0.3, 5.55 ± 0.8 g/100 g freeze‐dried sample respectively), while glycine was the most abundant amino acid in P. lividus (10.34 ± 1.0 g/100g freeze‐dried sample).     

Evaluating Ascorbate Oxidase as a Plant Defense Against Leaf-Chewing Insects Using Transgenic Poplar

Ascorbate is the major water-soluble antioxidant in plants and animals, and it is an essential nutrient for most insect herbivores. Therefore, ascorbate oxidase (AO) has been proposed to function as a plant defense that decreases the availability of ascorbate to insects. This hypothesis was tested by producing transgenic poplar (Populus tremula × Populus alba; Salicaceae) with 14- to 37-fold higher foliar AO activities than control (wild type) leaves and feeding these leaves to Lymantria dispar L. (Lepidoptera: Lymantriidae) caterpillars and Melanoplus sanguinipes (Fabricius) (Orthoptera: Acrididae) grasshoppers. To examine potential mechanisms of activity of AO in these insects, ascorbyl radical and/or ascorbate levels were measured in gut contents. No significant changes in ascorbyl radical or ascorbate levels were found in the midgut contents of L. dispar larvae that ingested the leaves of the AO-overexpressing genotypes compared to the control genotype, and no significant decreases in ascorbate levels were found in the foregut or midgut contents of M. sanguinipes. Treatment of control leaves with commercial AO also produced no changes in the midgut biochemistry of L. dispar larvae, as measured by levels of ascorbyl radicals. Likewise, no increase in oxidative stress was observed in L. dispar that consumed tannin-treated AO-overexpressing leaves compared with tannin-treated control genotype leaves. Performance experiments were carried out on first- and fourth-instar L. dispar larvae on leaf disks and on third instars feeding on intact leaves on trees. In no case was a significant difference found in the contrast between the control and three AO-overexpressing genotypes for relative consumption rate, relative growth rate, or nutritional indices. We conclude that elevated levels of AO in poplar are unlikely to serve as a defense against herbivores such as L. dispar or M. sanguinipes and that the low oxygen levels commonly found in the guts of caterpillars and grasshoppers may limit the activity of ingested AO in these leaf-chewing insects.     

Shared virtual memory clusters: bridging the cost-performance gap between SMPs and hardware DSM systems

Although the shared memory abstraction is gaining ground as a programming abstraction for parallel computing, the main platforms that support it, small-scale symmetric multiprocessors (SMPs) and hardware cache-coherent distributed shared memory systems (DSMs), seem to lie inherently at the extremes of the cost-performance spectrum for parallel systems. In this paper we examine if shared virtual memory (SVM) clusters can bridge this gap by examining how application performance scales on a state-of-the-art shared virtual memory cluster. We find that: (i) The level of application restructuring needed is quite high compared to applications that perform well on a DSM system of the same scale and larger problem sizes are needed for good performance. (ii) However, surprisingly, SVM performs quite well for a fairly wide range of applications, achieving at least half the parallel efficiency of a high-end DSM system at the same scale and often much more.     

Reflectivity properties of an anisotropic slab waveguide with isolated substrate

The scattering properties for both TE and TM modes of an abruptly ended two-layered slab waveguide with anisotropic core and isolated substrate are examined by an improved iteration technique, which is based on the integral equation method with accelerating parameters. The relative dielectric constants of the core for the three Cartesian directions are considered to be different, but cases with isotropic core are also considered. The electric field distribution on the terminal plane and the reflection coefficients of the dominant TE and TM guided modes, as well as the near-field distribution and the far-field radiation pattern, are computed, while numerical results are presented for several cases of the core anisotropy.     

Mesostructured Silica for Optical Functionality, Nanomachines, and Drug Delivery

Silica thin films and nanoparticles prepared using sol–gel chemistry are derivatized with active molecules to generate new functional materials. The mild conditions associated with sol–gel processing allow for the incorporation of a range of dopants including organic or inorganic dyes, biomolecules, surfactants, and molecular machines. Silica nanoparticles embedded with inorganic nanocrystals, and films containing living cells have also been synthesized. Silica templated with surfactants to create mesostructure contains physically and chemically different regions that can be selectively derivatized using defined techniques to create dynamic materials. Using two different techniques, donor–acceptor pairs can be doped into separated regions simultaneously and photo-induced electron transfer between the molecules can be measured. Mesoporous silica materials are also useful supports for molecular machines. Machines including snap-tops and nanoimpellers that are designed to control the release of guest molecules trapped within the pores are described. Mesoporous silica nanoparticles are promising materials for drug delivery and other biomedical applications because they are nontoxic and can be taken up by living cells. Through appropriate design and synthesis, multifunctional mesoporous silica nanoparticles for sophisticated bio-applications are created.     

Die Bestimmung der Rohfaser in Kakao und Cerealien

Ohne ZusammenfassungMitteilung aus der Staatl. Untersuchungsanstalt für Lebensmittel beim Hygienischen Institut in Leipzig. (Vorstand: Prof. Dr. Härtel.)     

Proximate composition, fatty acid analysis and protein digestibility-corrected amino acid score of three Mediterranean cephalopods

Proximate composition, fatty acid analysis and protein digestibility-corrected amino acid score (PDCAAS) in three commercially important cephalopods of the Mediterranean sea (cuttlefish, octopus and squid) were determined. The results of the proximate analysis showed that these species had very high protein:fat ratios similar to lean beef. Docosahexaenoic, palmitic and eicosipentaenoic acid were the most abundant fatty acids among analyzed species. The amount of n-3 fatty acids was higher than that of saturated, monounsaturated and n-6 fatty acids. Despite the fact that cephalopods contain small amounts of fat they were found quite rich in n-3 fatty acids. Finally, PDCAAS indicated that these organisms had a very good protein quality.