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Selected AbstractsFabrication of a Sensitive Cholesterol Biosensor Based on Cobalt-oxide Nanostructures Electrodeposited onto Glassy Carbon ElectrodeELECTROANALYSIS, Issue 24 2009Abdollah Salimi Abstract Electrodeposited cobalt oxide (CoOx) nanomaterials are not only used for immobilization of cholesterol oxidase (ChOx) but also as electron transfer mediator for oxidation of H2O2 generated in the enzymatic reaction. Voltammetry and flow injection analysis (FIA) were used for determination of cholesterol. FIA determination of cholesterol with biosensors yielded a calibration curve with the following characteristics: linear range up to 50,,M, sensitivity of 43.5,nA ,M,1 cm,2 and detection limit of 4.2,,M. The apparent Michaelis-Menten constant and the response time of the biosensor are 0.49,mM and 15,s, respectively. This biosensor also exhibits good stability, reproducibility and long life time. [source] High-buffering capacity, hydrolytically stable, low-pI isoelectric membranes for isoelectric trapping separationsELECTROPHORESIS, Issue 20 2004Sanjiv Lalwani Abstract Hydrolytically stable, low-pI isoelectric membranes have been synthesized from low-pI ampholytic components, poly(vinyl alcohol), and a bifunctional cross-linker, glycerol-1,3-diglycidyl ether. The low-pI ampholytic components used contain one amino group and at least two weakly acidic functional groups. The acidic functional groups are selected such that the pI value of the ampholytic component is determined by the pKa values of the acidic functional groups. When the concentration of the ampholytic component incorporated into the membrane is higher than a required minimum value, the pI of the membrane becomes independent of variations in the actual incorporation rate of the ampholytic compound. The new, low-pI isoelectric membranes have been successfully used as anodic membranes in isoelectric trapping separations with pH < 1.5 anolytes and replaced the hydrolytically less stable polyacrylamide-based isoelectric membranes. The new low-pI isoelectric membranes have excellent mechanical stability, low electric resistance, good buffering capacity, and long life time, even when used with as much as 50 W power and current densities as high as 33 mA/cm2 during the isoelectric trapping separations. [source] Crystal Structure, Solid-State NMR Spectroscopic and Photoluminescence Studies of Organic-Inorganic Hybrid Materials (HL)6[Ge6(OH)6(hedp)6]·2(L)·nH2O, L = hqn or phen,EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 23 2006Luís Mafra Abstract Two germanium,hedp4, solids with heteroaromatic amines 8-hydroxyquinoline (hqn) and 1,10-phenanthroline (phen), (HL)6[Ge6(OH)6(hedp)6]·2(L)·nH2O (L = hqn or phen), in I and II respectively, have been prepared and characterised by single-crystal XRD, thermogravimetry, FTIR and UV/Vis spectroscopy. The complex hydrogen-bond networks, particularly in compound I, have been studied by advanced high-resolution solid-state NMR spectroscopy that combines homonuclear recoupling techniques (two-dimensional 1H- 1H DQF and 1H- 1H RFDR MAS NMR) and combined rotation and multiple-pulse spectroscopy (two-dimensional 1H- 1H FS-LG, 1H- 31P FS-LG). The fine details of the crystal structure of I have been elucidated, mainly those involving the ,,, stacking of 8-hydroxyquinoline and the relative orientation of adjacent such molecules. Compound II exhibits an emission from the lowest triplet-state energy (,,,* 0-phonon transition) of the aromatic rings at 320 nm (31250 cm,1) from 14 K to room temperature. In contrast, the triplet emission of I at 530 nm (18868 cm,1) is only detected at low temperature, because of thermally activated non-radiative mechanisms. The emission spectra of I and II display a lower-energy component with a larger life time, which results from the formation of an excimer state that originated from the ,,, phenanthroline and hydroxyquinoline interactions, respectively. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Lipid damage in farmed rainbow trout (Oncorhynchus mykiss) after slaughtering and chilled storageEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 12 2008Jaime Ortiz Abstract The flow ice system including ozone (OFI condition) was tested for slaughtering and storage (up to 16,days) of farmed rainbow trout (Oncorhynchus mykiss). Lipid damage analyses were carried out and compared to sensory acceptance and instrumental colour changes. Comparison to individuals processed with the flow ice system in the absence of ozone (FI condition) was undertaken. Rainbow trout slaughtered and chilled under FI and OFI conditions showed a low lipid damage development, according to lipid oxidation and hydrolysis events and lipid composition (polyunsaturated fatty acids, phospholipids and endogenous antioxidants) changes. Additionally, both icing conditions led to largely good quality and shelf life times and to the absence of changes in colour properties. It is concluded that flow ice as such, or including the presence of ozone, can be considered as ideal strategy to be employed as slaughtering and storage system during the commercialisation of the actual farmed species. The ozone presence has shown some profitable effects as leading to an extended shelf life time by quality retention of several sensory parameters; in contrast, some negligible negative effects could be observed on the secondary and tertiary lipid oxidation development. However, the oxidation values reached by individuals kept under OFI conditions cannot be considered as particularly high. [source] Close Proximity Dibenzo[a,c]phenazine,Fullerene Dyad: Synthesis and Photoinduced Singlet Energy TransferEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 18 2010Rajeev K. Dubey Abstract A dibenzo[a,c]phenazine,fullerene (DBPZ-C60) dyad in which two chromophores are linked in close proximity to each other has been synthesized and studied in detail by optical spectroscopy to explore a new energy donor,acceptor system. The dyad was prepared by Prato reaction between 11-formyldibenzo[a,c]phenazine and fullerene. 3,5-Di- tert -butylbenzyl group was introduced onto the fulleropyrrolidine unit to achieve adequate solubility of the dyad. A thorough study of the photophysical properties of the dyad and relevant reference compounds, performed by means of steady state and time resolved spectroscopic measurements, has revealed the presence of highly efficient (ca. 98,%) and extremely fast (ken = 5,×,1011 s,1) intramolecular photoinduced singlet,singlet energy-transfer process from singlet excited state of the DBPZ moiety to fullerene. In both polar and nonpolar environment transduction of singlet excited state energy governs the excited state deactivation, but the efficiency and rate of energy transfer were found to be higher in nonpolar solvents in comparison to polar. The DBPZ singlet excited state decays within 2 and 4.7 ps in toluene andbenzonitrile, respectively, via singlet,singlet energy transfer to produce a fullerene singlet excited state which decays with a life time of 1.5 ns to give a very long-lived fullerene triplet state as final populated excited state. [source] The importance of being persistent: heterogeneity of bacterial populations under antibiotic stressFEMS MICROBIOLOGY REVIEWS, Issue 4 2009Orit Gefen Abstract While the DNA sequence is largely responsible for transmitting phenotypic traits over evolutionary time, organisms are also considerably affected by phenotypic variations that persist for more than one generation, with no direct change in the organisms' DNA sequence. In contrast to genetic variation, which is passed on over many generations, the phenotypic variation generated by nongenetic mechanisms is difficult to study due to the inherently limited life time of states that are not encoded in the DNA sequence, but makes it possible for the ,memory' of past environments to influence future organisms. One striking example of phenotypic variation is the phenomenon of bacterial persistence, whereby genetically identical bacterial populations respond heterogeneously to antibiotic treatment. Our aim is to review several experimental and theoretical approaches to the study of persistence. We define persistence as a characteristic of a heterogeneous bacterial population that is taken as a generic example through which we illustrate the approach and study the dynamics of population variability. The clinical and evolutionary implications of persistence are discussed in light of the mathematical description. This approach should be of relevance to the study of other phenomena in which nongenetic variability is involved, such as cellular differentiation or the response of cancer cells to treatment. [source] Regional anticoagulation and antiaggregation for CVVH in critically ill patients: a prospective, randomized, controlled pilot studyACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 1 2010L. P. FABBRI Background: The aim of this study is to assess the efficacy and clinical safety of regional anticoagulation (heparin pre-filter plus post-filter protamine) plus antiaggregation (pre-filter prostacyclin) [Group 1 (G1)] vs. only systemic heparin anticoagulation without antiaggregation [Group 2 (G2)] in critically ill patients with acute renal failure undergoing continuous veno-venous haemofiltration (CVVH). Methods: One hundred and ten patients were randomized in a prospective, controlled pilot study. G1 patients received 1000 U/h pre-filter heparin, 10 mg/h post-filter protamine sulphate and 4 ng/kg/min pre-filter prostacyclin, while G2 patients received 1000 U/h pre-filter heparin. The haemofilter transmembrane pressure (TMP) and lifespan, as well as the platelet count were observed 1 h before, and at 6, 12, 18, 24 and 36 h from the beginning of CVVH. Results: Haemofilter TMP remained unchanged in G1 while it increased up to three times in G2 (P=0.0002). The median filter lifespan was 68 h in G1 and 19 h in G2. The rate of spontaneous circuit failure was 24% in G1 and 93% in G2 (P=0.0001). The platelet count was stable over the treatment period in G1 while in G2 it decreased progressively (P=0.0073). Conclusion: In critically ill patients suffering from acute renal failure, regional anticoagulation with pre-filter heparin and post-filter protamine plus antiaggregation during CVVH is a simple and safe procedure that prevents increases in filter TMP and increases circuit life time compared with systemic anticoagulation with pre-filter heparin only. [source] Hybrid titanium catalyst supported on core-shell silica/poly(styrene- co -acrylic acid) carrierJOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2010Lijun Du Abstract Hybrid titanium catalysts supported on silica/poly(styrene- co -acrylic acid) (SiO2/PSA) core-shell carrier were prepared and studied. The resulting catalysts were characterized by Fourier transform infrared (FTIR) spectroscopy, laser scattering particle analyzer and scanning electronic microscope (SEM). The hybrid catalyst (TiCl3/MgCl2/THF/SiO2·TiCl4/MgCl2/PSA) showed core-shell structure and the thickness of the PSA layer in the two different hybrid catalysts was 2.0 ,m and 5.0 ,m, respectively. The activities of the hybrid catalysts were comparable to the conventional titanium-based Ziegler-Natta catalyst (TiCl3/MgCl2/THF/SiO2). The hybrid catalysts showed lower initial polymerization rate and longer polymerization life time compared with TiCl3/MgCl2/THF/SiO2. The activities of the hybrid catalysts were enhanced firstly and then decreased with increasing P/P. Higher molecular weight and broader molecular weight distribution (MWD) of polyethylene produced by the core-shell hybrid catalysts were obtained. Particularly, the hybrid catalyst with a PSA layer of 5.0 ,m obtained the longest polymerization life time with the highest activity (2071 kg PE mol,1 Ti h,1) and the resulting polyethylene had the broadest MWD (polydispersity index = 11.5) under our experimental conditions. The morphology of the polyethylene particles produced by the hybrid catalysts was spherical, but with irregular subparticles due to the influence of PSA layer. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Electrochemical, ESR and quantum chemical study of 1-substituted naphthalenes and their radical anions,,JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 1 2008N. V. Vasilieva Abstract Electrochemical reduction and oxidation of a series of 1-substituted naphthalenes (1-X-naphthalenes) have been studied by the method of cyclic voltammetry (CV). The first reduction peak of the majority of these compounds corresponds to a one-electron transfer to form the relatively stable radical anion (RA). For these species, ESR spectra have been registered and interpreted, the life time has been estimated. The first oxidation peaks of 1-X-naphthalenes are irreversible and correspond to a transfer of two or more electrons. Copyright © 2007 John Wiley & Sons, Ltd. [source] Residual stress analysis of an autofrettaged compound cylinder under machining processMATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK, Issue 3 2009E.-Y. Lee Autofrettage; Schrumpfpassung; Verbundzylinder; Bearbeitungsprozess Abstract The autofrettage process is used to manufacture pressure vessels and cylinders that can withstand high internal pressure. A multi-layered cylinder was assembled by a shrink fit. Autofrettaged compound cylinder can resist higher internal pressure than a thick cylinder having the same dimension and extend its life time. Inner and outer surfaces of the autofrettaged compound cylinder have to be manufactured into exact dimensions. The distribution of residual stress can change after the machining process. The machining procedure of inner and outer surfaces also affects the distribution of residual stress as a function of the machining procedure. In this study, the distribution of residual stresses of an autofrettaged compound cylinder as machining procedure was investigated using analytical and numerical analyses. [source] On the availability of R out of N repairable systemsNAVAL RESEARCH LOGISTICS: AN INTERNATIONAL JOURNAL, Issue 5 2002Esther Frostig Abstract An R out of N repairable system consisting of N components and operates if at least R components are functioning. Repairable means that failed components are repaired, and upon repair completion they are as good as new. We derive formulas for the expected up-time, expected down-time, and the availability of the system, using Markov renewal processes. We assume that either the repair times of the components are generally distributed and the components' lifetimes are exponential or vice versa. The analysis is done for systems with either cold or warm stand-by. Numerical examples are given for several life time and repair time distributions. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 483,498, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/nav.10025 [source] Transparent carbon nanotube field emission devices for display and lampPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 6 2007Yousuk Cho Abstract A new, simple method to fabricate transparent carbon nanotube field emission devices is developed. The highly graphitized, single wall carbon nanotubes (SWNTs) are attached to an Sn/ITO glass by the arc discharge method. Post-heat treatments of the sample below the deformation temperature of soda-lime glass form a Sn,SWNT composite, and the nanotubes form good mechanical adhesion and electrical contact with the substrates. When the composite is oxidized in air below 400 °C, the Sn particles change to a transparent oxide form. The emission current density of the heat-treated SWNT,Sn composite is about 1 mA/cm2 at an electric field of 3 V/,m. The emission current density of the SWNT,SnOx composite is similar. However, at a higher oxidation temperature, the emitter shows more stable emission property and longer life time. The transparency of the emitter can be useful in the design of emitter devices. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Role of rare earth elements as co-activators on both PL and afterglow of CaGa2S4:EuPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 5 2009Chiharu Hidaka Abstract Photoluminescence and afterglow spectra of Eu and rare earth elements (REE) doped CaGa2S4 have been measured. Nd, Dy and Ho ions are selected as sensitizers to make the afterglow (Eu green-emission) long. The longest afterglow is observed at Eu and Ho co-doping. We have also measured the dependence of the afterglow on Eu concentration. As Eu concentration decreases, the decay time is longer in the cases of Nd, Dy and Ho co-doping. This is explained by the decrease in the probability of the life time of electrons in the electron reservoirs, as the distances between Eu and REE (Nd,Dy,Ho) ions are far from each other. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Effect of electron-electron interaction on the diffusion current of spin-polarized electronsPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 1 2008Yutaka Takahashi Abstract Electron-electron interaction modifies carrier transport in the spin-polarized system. The effects are investigated in the two-dimensional electron gas in semiconductor heterostructures. We find that the diffusion currents of spin-up and spin-down electrons are reduced, compared to the non-interacting values, by the momentum exchange between spin-up and spin-down electrons through their collisions (Spin Drag), and also by the electron energy renormalization arising from the manyparticle correlations. We numerically calculate the diffusion coefficients of spin-up and spin-down electrons separately in high-quality heterostructures of GaAs at low temperatures, including the effect of finite spin life time. Our calculations show that the diffusion coefficients are reduced down to less than half of their non-interacting values. We also find the negative diffusivity at low temperatures. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Evolution of magnetic fields in stars across the upper main sequence: II.ASTRONOMISCHE NACHRICHTEN, Issue 6 2007Observed distribution of the magnetic field geometry Abstract We re-discuss the evolutionary state of upper main sequence magnetic stars using a sample of Ap and Bp stars with accurate Hipparcos parallaxes and definitely determined longitudinal magnetic fields. We confirm our previous results obtained from the study of Ap and Bp stars with accurate measurements of the mean magnetic field modulus and mean quadratic magnetic fields that magnetic stars of mass M < 3 M, are concentrated towards the centre of the main-sequence band. In contrast, stars with masses M > 3 M, seem to be concentrated closer to the ZAMS. The study of a few known members of nearby open clusters with accurate Hipparcos parallaxes confirms these conclusions. Stronger magnetic fields tend to be found in hotter, younger and more massive stars, as well as in stars with shorter rotation periods. The longest rotation periods are found only in stars which spent already more than 40% of their main sequence life, in the mass domain between 1.8 and 3 M, and with log g values ranging from 3.80 to 4.13. No evidence is found for any loss of angular momentum during the main-sequence life. The magnetic flux remains constant over the stellar life time on the main sequence. An excess of stars with large obliquities , is detected in both higher and lower mass stars. It is quite possible that the angle , becomes close to 0. in slower rotating stars of mass M > 3 M, too, analog to the behaviour of angles , in slowly rotating stars of M < 3 M,. The obliquity angle distribution as inferred from the distribution of r -values appears random at the time magnetic stars become observable on the H-R diagram. After quite a short time spent on the main sequence, the obliquity angle , tends to reach values close to either 90. or 0. for M < 3 M,. The evolution of the obliquity angle , seems to be somewhat different for low and high mass stars. While we find a strong hint for an increase of , with the elapsed time on the main sequence for stars with M > 3 M,, no similar trend is found for stars with M < 3 M,. However, the predominance of high values of , at advanced ages in these stars is notable. As the physics governing the processes taking place in magnetised atmospheres remains poorly understood, magnetic field properties have to be considered in the framework of dynamo or fossil field theories. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Prevalence of adverse life events, depression and suicidal thoughts and behaviour among a community sample of young people aged 15,24 yearsAUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH, Issue 5 2001Maria Donald Objective: To provide prevalence data on several key mental health indicators for young people aged 15 to 24 years. Methods: A cross-sectional household survey, using telephone recruitment followed by a postal pencil-and-paper questionnaire. The overall response rate was 67.3%. Results: Difficulties with interpersonal relationships are common causes of distress for young people, in particular problems with parents, problems with friends and relationship break-ups. Depressive symptomatology is common among young people with approximately one in eight males and one in four females reporting current depressive symptomatology. One in three young people reported that they had had suicidal thoughts at some time in the past, 1.2% of young people reported that they had made a plan on how to kill themselves in the four-week period prior to completing the survey and 6.9% of young people reported that they had tried to kill themselves at some time during their life time (4.2% of males and 9.0% of females). Conclusions and implications: The prevalence figures for the various mental health indicators presented in this paper represent good baseline information upon which to examine the progress over time of interventions designed to improve the mental health of young people. [source] In this issue: Biotechnology Journal 8/2010BIOTECHNOLOGY JOURNAL, Issue 8 2010Article first published online: 12 AUG 2010 Biocatalyst microemulsions Pavlidis et al., Biotechnol. J. 2010, 5, 805,812 Enzymes maintain their catalytic activity when hosted in aqueous nanodroplets like reverse micelles. Researchers from Ioannina, Greece, propose the use of water-in-ionic liquid microemulsionbased organogels (w/IL MBGs) as novel supports for the immobilization of lipase B from Candida antarctica and lipase from Chromobacterium viscosum. These novel lipase-containing w/IL MBGs can be effectively used as solid phase biocatalysts in various polar and non-polar organic solvents or ILs, exhibiting up to 4.4-fold higher esterification activity compared to water-in-oil microemulsion-based organogels. The immobilized lipases retain their activity for several hours at 70°C, while their half life time is up to 25-fold higher compared to that observed in w/IL microemulsions Biocatalyst cryogelation Bieler et al., Biotechnol. J. 2010, 5, 881,885 Entrapment of biocatalysts in hydrogel beads allows stable operation in otherwise deteriorating solvents. Doing this by cryogelation is a gentle method to extend the scope of biocatalysis. To foster the use of this versatile method, researchers from Aachen, Germany, devised an automated injector for the production of PVA/PEG-enzyme immobilisates. The device consists of a thermostated reservoir connected to a programmable injector nozzle and an agitated receiving bath for the droplets. This lab-scale production unit yields up to 1500 beads with immobilized enzyme per minute with a narrow size distribution and good roundness. Biocatalyst membrane reactor Lyagin et al., Biotechnol. J. 2010, 5, 813,821 Screening of biocatalysts, substrates or conditions in the early stages of bioprocess development requires an enormous number of experiments and is a tedious, expensive and time-consuming task. Currently available screening systems can only be operated in batch or fed-batch mode, which can lead to severe misinterpretations of screening results. Researchers from Berlin, Germany, now developed a novel screening system that enables continuous feeding of substrates and continuous removal of products. A prototype based on the membrane reactor concept was designed and operated for a model reaction, the hydrolysis of cellulose. [source] Water-in-ionic liquid microemulsion-based organogels as novel matrices for enzyme immobilizationBIOTECHNOLOGY JOURNAL, Issue 8 2010Ioannis V. Pavlidis Abstract The use of water-in-ionic liquid microemulsion-based organogels (w/IL MBGs) as novel supports for the immobilization of lipase B from Candida antarctica and lipase from Chromobacterium viscosum was investigated. These novel lipase-containing w/IL MBGs can be effectively used as solid phase biocatalysts in various polar and non-polar organic solvents or ILs, exhibiting up to 4.4-fold higher esterification activity compared to water-in-oil microemulsion-based organogels. The immobilized lipases retain their activity for several hours at 70°C, while their half life time is up to 25-fold higher compared to that observed in w/IL microemulsions. Fourier-transform infrared spectroscopy data indicate that immobilized lipases adopt a more rigid structure, referring to the structure in aqueous solution, which is in correlation with their enhanced catalytic behavior observed. [source] Very High Yield Growth of Vertically Aligned Single-Walled Carbon Nanotubes by Point-Arc Microwave Plasma CVD,CHEMICAL VAPOR DEPOSITION, Issue 3 2005F. Zhong A very high yield, selective growth of dense, vertically aligned single-walled carbon nanotubes (SWNTs) has been demonstrated for the first time on Si substrates with a sandwich-like coating structure of Al2O3/Fe/Al2O3 at a low (600,°C) temperature by point-arc microwave plasma CVD. The SWNT film thickness increases continuously with the growth time, suggesting an almost unlimited life time for the catalyst. A film thickness of 420,,m, and production yield of SWNTs to catalyst of about 770,000,% can be achieved within 2,h. [source] Object combining: a new aggressive optimization for object intensive programsCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 5-6 2005Ronald Veldema Abstract Object combining tries to put objects together that have roughly the same life times in order to reduce strain on the memory manager and to reduce the number of pointer indirections during a program's execution. Object combining works by appending the fields of one object to another, allowing allocation and freeing of multiple objects with a single heap (de)allocation. Unlike object inlining, which will only optimize objects where one has a (unique) pointer to another, our optimization also works if there is no such relation. Object inlining also directly replaces the pointer by the inlined object's fields. Object combining leaves the pointer in place to allow more combining. Elimination of the pointer accesses is implemented in a separate compiler optimization pass. Unlike previous object inlining systems, reference field overwrites are allowed and handled, resulting in much more aggressive optimization. Our object combining heuristics also allow unrelated objects to be combined, for example, those allocated inside a loop; recursive data structures (linked lists, trees) can be allocated several at a time and objects that are always used together can be combined. As Java explicitly permits code to be loaded at runtime and allows the new code to contribute to a running computation, we do not require a closed-world assumption to enable these optimizations (but it will increase performance). The main focus of object combining in this paper is on reducing object (de)allocation overhead, by reducing both garbage collection work and the number of object allocations. Reduction of memory management overhead causes execution time to be reduced by up to 35%. Indirection removal further reduces execution time by up to 6%. Copyright © 2005 John Wiley & Sons, Ltd. [source] Lipid damage in farmed rainbow trout (Oncorhynchus mykiss) after slaughtering and chilled storageEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 12 2008Jaime Ortiz Abstract The flow ice system including ozone (OFI condition) was tested for slaughtering and storage (up to 16,days) of farmed rainbow trout (Oncorhynchus mykiss). Lipid damage analyses were carried out and compared to sensory acceptance and instrumental colour changes. Comparison to individuals processed with the flow ice system in the absence of ozone (FI condition) was undertaken. Rainbow trout slaughtered and chilled under FI and OFI conditions showed a low lipid damage development, according to lipid oxidation and hydrolysis events and lipid composition (polyunsaturated fatty acids, phospholipids and endogenous antioxidants) changes. Additionally, both icing conditions led to largely good quality and shelf life times and to the absence of changes in colour properties. It is concluded that flow ice as such, or including the presence of ozone, can be considered as ideal strategy to be employed as slaughtering and storage system during the commercialisation of the actual farmed species. The ozone presence has shown some profitable effects as leading to an extended shelf life time by quality retention of several sensory parameters; in contrast, some negligible negative effects could be observed on the secondary and tertiary lipid oxidation development. However, the oxidation values reached by individuals kept under OFI conditions cannot be considered as particularly high. [source] Assessing future changes in extreme precipitation over Britain using regional climate model integrationsINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 11 2001P.D. Jones Abstract In a changing climate it is important to understand how all components of the climate system may change. For many impact sectors, particularly those relating to flooding and water resources, changes in precipitation intensity and amount are much more important than changes in temperature. This study assesses possible changes in extreme precipitation intensities estimated through both quantile and return period analysis over Britain. Results using a regional climate model (with greenhouse gas changes following the IS92a scenario for 2080,2100) indicate dramatic increases in the heaviest precipitation events over Britain. The results provide information to alter design storm intensities to take future climate change into account, for structures/projects that have long life times. Copyright © 2001 Royal Meteorological Society [source] Influence of sex hormones on the periodontiumJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 8 2003Paulo Mascarenhas Abstract Objectives: Sex hormones have long been considered to play an influential role on periodontal tissues, bone turnover rate, wound healing and periodontal disease progression. The objectives of this review article are to (1) address the link between sex hormones and the periodontium, (2) analyse how these hormones influence the periodontium at different life times and (3) discuss the effects of hormone supplements/replacement on the periodontium. Materials and Methods: Two autonomous searches were performed in English language utilizing Medline, Premedline and Pubmed as the online databases. Publications up to 2002 were selected and further reviewed. In addition, a manual search was also performed including specific related journals and books. Results: It is certain that sexual hormones play a key role in periodontal disease progression and wound healing. More specifically, these effects seem to differentiate by gender as well as lifetime period. In addition, the influence of sex hormones can be minimized with good plaque control and with hormone replacement. Conclusion: Despite profound research linking periodontal condition with sex hormones kinetics, more definitive molecular mechanisms and therapy still remain to be determined. Zusammenfassung Männliche und weibliche Sexualhormone wurden schon lange einen wichtigen Einfluss auf das parodontale Gewebe, die Knochenumsatzrate, die Wundheilung und die parodontale Erkrankungsprogression ausübend betrachtet. Der Einfluss dieser Hormone auf das Parodontium unterscheidet sich zu verschiedenen physiologischen Phasen (z.B. Pubertät, Schwangerschaft, post Menopause) und mit der Einnahme von Pharmaka (z.B. Antikonzeptiva, Hormonsubstitution). Deshalb ist der Zweck dieses Reviewartikels (1) die Beziehung zwischen Sexualhormonen und dem Parodontium zu beschreiben, (2) die Analyse des Einflusses dieser Hormone auf das Parodontium zu unterschiedlichen Lebenszeiten und (3) die Effekte von Hormonunterstützung/substitution auf das Parodontium zu diskutieren. Résumé On a longtemps considéré que les hormones sexuelles, aussi bien masculines que féminines, jouaient un rôle important sur les tissus parodontaux, le taux de remaniement osseux, la cicatrisation et la progression de la maladie parodontale. L'influence de ces hormones sur le parodonte est différente en fonction des divers conditions physiologiques (par exemple, la puberté, la grossesse, et après la ménopause) et les prises de médicaments (par exemple, la pillule contraceptive et les traitements hormonaux de substitution). Aussi, cette revue critique de la littérature se propose (1) de faire le point sur les liens entre les hormones sexuelles et le parodonte (2) d' analyser la façon dont ces hormones influencent le parodonte lors des différentes étapes de la vie, et (3) discuter les effets des hormones de substitution sur le parodonte. [source] Oxidation behaviour of Fe-Cr-Al alloys during resistance and furnace heatingMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 2 2006H. Echsler Abstract The behaviour of thin Fe-Cr-Al heating element strips was investigated with respect to the oxidation limited life times and geometrical changes during resistance and furnace heating. For this purpose, isothermal and cyclic oxidation tests varying in their total exposure time and cycle duration were performed in the temperature range 1050,1200 °C. Specimens subjected to rapid cyclic, resistance heating revealed shorter life times than calculated for specimens subjected to isothermal exposure. The life times were found to increase with increasing cycle duration and hence decreasing number of cycles for a given time at temperature. This life time decrease is related to an "hour glass" waviness of the specimens, which develops during prolonged thermal cycling. The development of this plastic deformation also occurred during furnace heated, thermal cycling tests. A two-step mechanism is introduced combining an oxidation kinetics related time to the onset of significant waviness with an enhancement of this waviness as a result of a ratcheting effect. The latter seems to strongly depend on the number of cycles and on the plastic deformation generated during each cycle rather than on the total time at temperature. The development of an "hour glass" waviness leads to an enhanced aluminium depletion due to an increase of the specimen surface area. Additional deformation phenomena like "hot tube" or "corkscrew" behaviour occur during the resistance heating tests. These are related to a temperature gradient that develops over the specimen width due to the poor aspect ratio of the specimens. [source] Lifespan and patterns of accumulation and mobilization of nutrients in the sugar-fed phorid fly, Pseudacteon tricuspisPHYSIOLOGICAL ENTOMOLOGY, Issue 3 2005Henry Y. Fadamiro Abstract., The effect of sugar feeding on the survival of adult phorid fly Pseudacteon tricuspis is investigated. Flies fed 25% sucrose in aqueous solution continuously throughout their lifespan have greater longevity (mean ± SE longevity: female = 7.9 ± 0.8 days, male = 8.9 ± 0.9 days) than completely starved (provided no water and no sugar solution) flies, sugar-starved (provided water only) flies, or flies fed sugar solution only on their first day of adult life. Completely starved flies rarely lived beyond one day. Provision of water increases longevity by 2 days, and one full day of sugar feeding further increases longevity by an additional 1,2 days. Flies fed 50% sucrose have similar survivorship as those fed 25% sucrose. The temporal patterns of nutrient accumulation and utilization are also compared in P. tricuspis fed different diets: sugar-starved, sucrose-fed on the first day of adult life only, and sucrose-fed continuously. Adult P. tricuspis emerge with no gut sugars, and only minimal amounts of body sugars and glycogen. Although the levels of body sugars and glycogen decline gradually in sugar-starved flies, a single day of sugar feeding results in the accumulation of maximum amounts of gut sugars, body sugars and glycogen. High levels of these nutrients are maintained in female and male phorid flies fed on sucrose continuously over the observation period, whereas nutrient levels decline in flies fed only on the first day of life, beginning 1 day postfeeding. Female and male P. tricuspis emerge with an estimated 12.3 ± 2.3 and 7.2 ± 1 g of lipid reserves per fly, respectively. These teneral amounts represent the highest lipid levels detected in adult flies, irrespective of their diet, and are maintained over the life times of sucrose-fed female and male flies, but declined steadily in sugar-starved females. These data suggest that adult P. tricuspis are capable of converting dietary sucrose to body sugars and glycogen, but not lipids. [source] Reactivity of organosilicon precursors in remote hydrogen microwave plasma chemical vapor deposition of silicon carbide and silicon carbonitride thin-film coatingsAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 3 2010A. M. Wrobel Abstract A number of organosilicon precursors for silicon carbide and silicon carbonitride thin-film coatings, such as silanes, carbosilanes, aminosilanes, and disilazane, respectively, were characterized in terms of their reactivity in a remote microwave plasma chemical vapor deposition process, which was induced using hydrogen as plasma generating gas. The process displayed high selectivity with respect to the activating species and the chemical bonds in the molecular structure of the precursors. In view of very short life times of excited hydrogen plasma species the activation step takes place with an exclusive contribution of ground-state hydrogen atoms. The CH, CC, SiC, SiN, CN and NH bonds present in the molecules of the precursors are non-reactive and only the SiH or SiSi bonds play a key role in the activation step. The reactivity of the precursors was characterized in a quantitative way by the yield of the film growth parameter. The yield parameter expressing the mass of film per unit mass of the precursor fed to the reactor was calculated from the slopes of linear plots of time dependencies of film mass and precursor mass, which were determined for each investigated precursor. The reactivity of the precursors was found to be strongly dependent on the number of the SiH units present in their molecules and those containing two SiH units appeared to be most reactive. Copyright © 2009 John Wiley & Sons, Ltd. [source] | |||||||||||||||||||||||||