EDGeS: Bridging EGEE to BOINC and XtremWeb

Desktop Grids, such as XtremWeb and BOINC, and Service Grids, such as EGEE, are two different approaches for science communities to gather computing power from a large number of computing resources. Nevertheless, little work has been done to combine these two Grid technologies in order to establish a seamless and vast Grid resource pool. In this paper we present the EGEE Service Grid, the BOINC and XtremWeb Desktop Grids. Then, we present the EDGeS solution to bridge the EGEE Service Grid with the BOINC and XtremWeb Desktop Grids.     

Aluminum: New challenges in downstream activities

During its history, aluminum’s attractive features, such as high strength-to-weight ratio, good electrical mass conductivity, and unique corrosion behavior, have led to a spectacular expansion in its use. The role of aluminum in non-aluminum-based materials is also very important; its contribution to the improvement of magnesium and titanium alloys and to highly complex packaging materials are some of the noteworthy examples. Significant cost reductions on the basic metal production level, near-to-shape fabricating methods, and the well-functioning recycling system are also major contributors to aluminum success. Imminent challenges for the industry are the need for products with very close tolerances on a mass fabricating repetitive basis and just-in-time delivery to original-equipment manufacturers and small users through distributors. A significant part of the challenges remains in the applications area, particularly automotive and aerospace.     

Protective materials for subpicosecond Ti:sapphire lasers

The high intensities provided by short-pulse Ti:sapphire laser systems call for the utilization of appropriate eye-protecting materials. We summarize the representative results of our characterization measurements on optical filters employed for laser radiation protection. Physical effects are discussed that influence the transmission (and thus the protective properties) of the investigated materials. Potential hazard factors have been recognized and characterized. We make recommendations to the extension of the current characterization methods and illustrate the acquired information in the form of operation charts.     

Electrophysiological and chemical analysis of sex pheromone communication system of the mottled umber,Erannis defoliaria (Lepidoptera: Geometridae)

(Z,Z,Z)-3,6,9-nonadecatriene (Z3,Z6,Z9–19Hy) and (Z,Z)-3,9-cis-6,7-epoxy-nonadecadiene (Z3,Z9-cis-6,7-epo-19Hy) were identified in pheromone gland extracts from femaleErannis defoliaria. The two components were found in a 13 ratio, with the main component,Z3,Z9-cis-6,7-epo-19Hy present at an amount of about 1.5 ng per female. The components were identified by means of gas chromatography-mass spectrometry, gas chromatography-electroantennography and gas chromatography-single sensillum recordings. Single sensillum measurements on the male antenna showed two physiological types of sensilla. One type was characterized by a large spike amplitude cell responding toZ3,Z9-cis-6,7-epoxy-19Hy and a small spike amplitude cell responding toZ3,Z6,Z9–19Hy. A second type responded only with a large spike amplitude cell to the epoxide, and this cell was inhibited by the triene. Of the two pheromone components, the epoxide gave the higher response in the EAG tests. Preliminary field tests support the identification of the pheromone components. The epoxide was also found to be present in the extract of the pheromone gland ofColotois pennaria, and males ofC. pennaria andAgriopis marginaria were trapped by the mixture of the identified compounds.     

Electron donors in carbocationic polymerization

Summary Low molecular weight (¯M_n 900–5000) narrow molecular weight distribution (MWD; ¯M_w/M_n = 1.1–1.2)tert.-chlorine telechelic polyisobutylenes (PIBs) have been synthesized by the use of thetrans-2,5-dimethyl-2,5-diacetoxy-3-hexene (DiOAcDMeH₆)/BCl₃ initiating system in the presence of the electron donor (ED) dimethyl sulfoxide (DMSO) in methyl chloride diluent at –30°C. The living character of the polymerization was demonstrated by linear M_n versus W_p (weight of polymer) plots starting at the origin with the slope of 1/[I_o] (where [I_o] = initiator concentration). DMSO reduces the overall rate of polymerization, however, it increases the initiator efficiency (I_eff) to 100%. The number averagetert.-chlorine end functionality is -F_n=1.97±0.04, by¹H NMR spectroscopy. Polymerization mechanistic details are discussed. This is the first time narrow MWDtert.-chlorine telechelic PIB has been prepared close to the reflux temperature of methyl chloride.Paper XXVII in the series on Living Carbocationic Polymerization. For paper XXVI see Kaszas et al., J. Macromol. Sci. Chem. to appear (1989)     

Analysing divided wall columns

In chemical processes, beside main products, significant quantities of by-products are often produced due to thermodynamics. Therefore, separation techniques and methods play such an important role, in chemical technologies, as reactor systems. Rectification is one of the most frequently used fluid separation process, which usually involves significant energy consumption. The production of hot and cold energy causes notable environmental load (CO₂ emission, dust pollution, etc.). Hence, from environmental point of view, research on energy saving in separation processes, for instance analysing divided wall columns (DWC), is exceedingly important. This article focuses on how to find more efficient structures with minimal energy consumption. The DWC system is a promising energy-saving alternative for separating multi-component mixtures (Chem Eng Process 38: 549–562, 1999; Chem Eng Process 49: 825–835, 2010). The innovation of this equipment is a wall which divides the inner space of the tower separating the feed and the side stream-product zones. The side stream and the feed stream are prevented from mixing by this wall. The DWC possesses greater efficiency than common column sequences. Conventional columns with side stream can be converted to DWC. In this article, several constructions of DWC are investigated with simulation experiments. The structure of the column is implemented in Aspen Plus in: 2006 Reference Guide, AspenTech Inc., Cambridge, 2006 simulator using the Radfrac unit of the software. The effects of the split ratio, the height and the vertical position of the wall, as the main parameters of DWC, are analysed.     

Effects of sampling rate on the interpretation of cellular transport measurements

Electrochemical sensing techniques are increasingly used to study biological processes by monitoring concentration changes of the molecule of interest close to cells. The measured concentration is the result of cellular transport across the cell membrane and diffusion of the released molecules from the cells to the sensing electrode. The objective of such experiments is to understand the cellular processes underlying the observed changes in concentration. Thus, the influence of mass transport on the measured concentration trace has to be removed. This is done by deconvolution of the impulse response function of diffusion from the concentration data. We have recently observed that measuring concentration at a sampling rate that satisfies the Nyquist criterion for the observed concentration dynamics may not be sufficient to correctly reconstruct cellular flux. This is because the impulse response function of diffusion also has to be represented with sufficient temporal resolution. We discuss this problem here using the example of monitoring drug efflux from a monolayer of cancer cells with microvoltammetry, and chloride secretion from an epithelial cell monolayer monitored with an ion-selective electrode.     

The role of the genome project in determining gene function: insights from model organisms

Peptido-leukotrienes are short-lived organic molecules known to have potent biological effects as mediators of inflammation, hypersensitivity and respiratory disorders. However, little is known concerning their effects on bone cells. We have shown previously that stromal cells isolated from a human giant cell tumor secrete 5-HETE (5-hydroxyeicosatetraenoic acid) and the peptido-leukotrienes, also known as the cysteinyl leukotrienes LTC4, LTD4, and LTE4. These eicosanoids were shown to stimulate the multinucleated giant cells obtained from these tumors to form resorption lacunae on sperm whale dentine. Here, we show that the peptido-leukotrienes also stimulate isolated avian osteoclast-like cells to form resorption lacunae and to increase their content of tartrate-resistant acid phosphatase. LTD4 increased 45Ca release from murine calvarial bone organ cultures, but not from fetal rat long bone cultures. Isolated avian osteoclast-like cells were chosen to perform receptor binding studies, as this population is the most homogeneous source of osteoclasts available. After the precursors had fused to form multinucleated cells, receptor binding assays were performed. Scatchard analysis of saturation binding data showed a single class of binding sites, with a dissociation constant (Kd) of 0.53 nM and a receptor density of 5,200 receptors per cell. Competition binding studies showed receptor specificity using a specific LTD4 receptor antagonist ZM 198,615. These data show that the peptido-leukotrienes activate highly enriched populations of isolated avian osteoclast-like cells, and also that specific LTD4 receptors are present in this cell population.