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Selected AbstractsPCR profiling of ammonia-oxidizer communities in acidic soils subjected to nitrogen and sulphur depositionFEMS MICROBIOLOGY ECOLOGY, Issue 2 2007Christoph Stephan Schmidt Abstract Communities of ammonia-oxidizing bacteria (AOB) were characterized in two acidic soil sites experimentally subjected to varying levels of nitrogen and sulphur deposition. The sites were an acidic spruce forest soil in Deepsyke, Southern Scotland, with low background deposition, and a nitrogen-saturated upland grass heath in Pwllpeiran, North Wales. Betaproteobacterial ammonia-oxidizer 16S rRNA and ammonia monooxygenase (amoA) genes were analysed by cloning, sequencing and denaturing gradient gel electrophoresis (DGGE). DGGE profiles of amoA and 16S rRNA gene fragments from Deepsyke soil in 2002 indicated no effect of nitrogen deposition on AOB communities, which contained both Nitrosomonas europaea and Nitrosospira. In 2003, only Nitrosospira could be detected, and no amoA sequences could be retrieved. These results indicate a decrease in the relative abundance of AOB from the year 2002 to 2003 in Deepsyke soil, which may be the result of the exceptionally low rainfall in spring 2003. Nitrosospira -related sequences from Deepsyke soil grouped in all clusters, including cluster 1, which typically contains only sequences from marine environments. In Pwllpeiran soil, 16S rRNA gene libraries were dominated by nonammonia oxidizers and no amoA sequences were detectable. This indicates that autotrophic AOB play only a minor role in these soils even at high nitrogen deposition. [source] PINK1 heterozygous rare variants: prevalence, significance and phenotypic spectrum,,HUMAN MUTATION, Issue 4 2008Roberta Marongiu Abstract Heterozygous rare variants in the PINK1 gene, as well as in other genes causing autosomal recessive parkinsonism, have been reported both in patients and healthy controls. Their pathogenic significance is uncertain, but they have been suggested to represent risk factors to develop Parkinson disease (PD). The few large studies that assessed the frequency of PINK1 heterozygotes in cases and controls yielded controversial results, and the phenotypic spectrum is largely unknown. We retrospectively analyzed the occurrence of PINK1 heterozygous rare variants in over 1100 sporadic and familial patients of all onset ages and in 400 controls. Twenty patients and 6 controls were heterozygous, with frequencies (1.8% vs. 1.5%) not significantly different in the two groups. Clinical features of heterozygotes were indistinguishable to those of wild-type patients, with mean disease onset 10 years later than in carriers of two mutations but worse disease progression. A meta-analysis indicated that, in PINK1 heterozygotes, the PD risk is only slightly increased with a non significant odds ratio of 1.62. These findings suggest that PINK1 heterozygous rare variants play only a minor susceptibility role in the context of a multifactorial model of PD. Hence, their significance should be kept distinct from that of homozygous/compound heterozygous mutations, that cause parkinsonism inherited in a mendelian fashion. © 2008 Wiley-Liss, Inc. [source] Race/Ethnic Differences in the Marital Expectations of Adolescents: The Role of Romantic RelationshipsJOURNAL OF MARRIAGE AND FAMILY, Issue 3 2005Sarah R. Crissey I use a sample of 12,973 adolescents in the National Longitudinal Study of Adolescent Health (Add Health) to examine race/ethnic differences in perception of the likelihood of marriage in adulthood and the role of heterosexual romantic relationship experience in explaining this difference. Compared to adolescents from other race/ethnic backgrounds, White adolescents are more likely to date and are especially more likely than Black adolescents to participate in serious romantic relationships that increase marital expectations. Although the type of current or recent relationship is associated with marital expectations, they do not explain the observed race/ethnic gap in these expectations. Overall, the results suggest that these adolescent romantic experiences likely play only a small role in determining differential marital expectations. [source] Exciton dephasing in quantum dots: Coupling to LO phonons via excited statesPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 6 2008E. A. Muljarov Abstract We have found a novel mechanism of spectral broadening and dephasing in quantum dots (QDs) due to the coupling to longitudinal-optical (LO) phonons. In theory, this mechanism comes into play only if the complete manifold of exciton levels (including those in the wetting-layer continuum) is taken into account. We demonstrate this nontrivial dephasing in different types of QDs, using the exactly solvable quadratic coupling model, here generalized to an arbitrary number of excitonic states. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Renal diagnosis of chronic hemodialysis patients with urinary tract transitional cell carcinoma in TaiwanCANCER, Issue 8 2007Chung-Hsin Chang MD Abstract BACKGROUND. Transitional cell carcinoma (TCC) is the most common malignancy in dialysis patients of Taiwan. The reason for such a high incidence of TCC is undetermined. The correlation between the underlying renal disease and the development of TCC was investigated. METHODS. The authors retrospectively reviewed the clinical data and outcome of 1537 chronic hemodialysis (HD) patients from 1993 to 2002. The incidence of TCC was computed. The Cox regression method was used to analyze the role of potential risk factors. RESULTS. After a mean dialysis duration of 46.5 months, 26 (1.69%) patients with TCC were diagnosed. The standardized incidence ratio (SIR) of TCC was 48.2 as compared with the general population and the SIR of TCC seemed higher in women (65.1) and in the age group 50 to 54 years (173.6). Of them, most cases showed no definite etiology. All these cases showed bilateral contracted kidneys. Nonnephrotic proteinuria was found in all cases and trace glucosuria was found in 17 (65%). Painless gross hematuria was the cardinal symptom and distant metastasis was rare. Also, TCC in upper urinary tracts were common and found in 14 (54%) of patients. Age at the time of dialysis, female sex, compound analgesic use, and Chinese herb use had statistical significance as risk factors (P < .05). CONCLUSIONS. Chronic HD patients have a high risk of TCC in Taiwan, especially in female and middle-aged patients. The study indicated that chronic tubulointerstitial nephritis (CTIN) is the most likely underlying renal disease in HD patients with TCC, a high percentage of the CTIN related to the usage of Chinese herbs or compound analgesics may contribute to the development of TCC, whereas diabetes or chronic glomerulonephritis play only a minor role. Cancer 2007. © 2007 American Cancer Society. [source] Interactions of ferricyanide with humic soils and charred strawEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 2 2008T. Rennert Summary The iron-cyanide complexes ferricyanide, [FeIII(CN)6]3,, and ferrocyanide, [FeII(CN)6]4,, are anthropogenic contaminants in soil. We studied the interactions of ferricyanide with humic soils and charred straw (maize and rye, both charred at 300, 400 and 500°C) by batch experiments and Fourier transform infrared (FTIR) spectroscopy. All soil samples sorbed ferricyanide (up to 8.4 g kg,1). Precipitation of a manganese ferrocyanide after reduction of ferricyanide in the moderately acidic to neutral soils was deduced from both FTIR spectroscopy (CN absorption bands at 2069,2065 cm,1) and geochemical modelling. Ferricyanide was also adsorbed onto the charred straw. The amounts of iron-cyanide complexes adsorbed increased with increasing charring temperature, with a maximum of 1.71 g kg,1. An absorption band at 2083 cm,1 indicated weakly adsorbed intermediates of the reduction of ferricyanide to ferrocyanide. This band disappeared in the samples charred at higher temperature, whereas a band at 2026 cm,1 was present in all spectra and became intensified in the high-temperature straw. We attribute this band to ferrocyanide forming inner-sphere complexes, presumably with quinone species of the organic matter. The band at 2026 cm,1 was also present in the spectra of the soils, indicating that soil organic matter also adsorbs ferrocyanide. However, in humic soils the main processes of ferricyanide interaction include reduction to ferrocyanide and precipitation as manganese ferrocyanide. Quantitatively, adsorption on highly aromatic substances plays only a less important role as compared with precipitation. [source] Quantitative modeling of triacylglycerol homeostasis in yeast , metabolic requirement for lipolysis to promote membrane lipid synthesis and cellular growthFEBS JOURNAL, Issue 22 2008Jürgen Zanghellini Triacylglycerol metabolism in Saccharomyces cerevisiae was analyzed quantitatively using a systems biological approach. Cellular growth, glucose uptake and ethanol secretion were measured as a function of time and used as input for a dynamic flux-balance model. By combining dynamic mass balances for key metabolites with a detailed steady-state analysis, we trained a model network and simulated the time-dependent degradation of cellular triacylglycerol and its interaction with fatty acid and membrane lipid synthesis. This approach described precisely, both qualitatively and quantitatively, the time evolution of various key metabolites in a consistent and self-contained manner, and the predictions were found to be in excellent agreement with experimental data. We showed that, during pre-logarithmic growth, lipolysis of triacylglycerol allows for the rapid synthesis of membrane lipids, whereas de novo fatty acid synthesis plays only a minor role during this growth phase. Progress in triacylglycerol hydrolysis directly correlates with an increase in cell size, demonstrating the importance of lipolysis for supporting efficient growth initiation. [source] Calling capital: call centre strategies in New Brunswick and New ZealandGLOBAL NETWORKS, Issue 2 2002Wendy Larner This article compares government promoted call centre initiatives in New Zealand and New Brunswick, Canada, thereby identifying differing policies and practices associated with ,globalization'. Both New Brunswick and New Zealand are small resource based economies in which policy makers aspire to attract foreign investment into call centres as a new means of economic growth and job creation. However there are significant differences between the two call centre strategies. In New Brunswick the provincial government plays a central role, most notably through the use of incentives to lure companies to the province but also through the coordination of education and training. In New Zealand an informal network made up of public and private sector actors drives the strategy, and the relevant government agency (Trade NZ) plays only a coordinating role. Despite these differences both call centre strategies aspire to link service sector activities into global flows and networks, and foster low wage and feminized forms of employment. [source] A tale of two ,globalizations': capital flows from rich to poor in two eras of global financeINTERNATIONAL JOURNAL OF FINANCE & ECONOMICS, Issue 4 2006Moritz Schularick Abstract In this paper we take a comparative look at the patterns of capital flows from rich to poor countries in two eras of financial globalization. The paper extends recent research on the developmental effects of international financial integration, long-term trends in capital mobility and ,globalization in historical perspective'. Analysing the patterns of international financial integration in the three decades of the classical gold standard and after 1990 we show that investment in developing countries was a central element of 19th century financial globalization, but plays only a minor role today. The Lucas paradox of capital failing to flow from rich to poor has grown much stronger. In historical perspective, today's financial globalization is marked by massive diversification flows between high-income economies and a relative marginalization of less-developed economies. Copyright © 2006 John Wiley & Sons, Ltd. [source] Mathematical modeling of 980-nm and 1320-nm endovenous laser treatmentLASERS IN SURGERY AND MEDICINE, Issue 3 2007Serge R. Mordon PhD Abstract Background and Objectives Endovenous laser treatment (ELT) has been proposed as an alternative in the treatment of reflux of the great saphenous vein (GSV) and small saphenous vein (SSV). Numerous studies have since demonstrated that this technique is both safe and efficacious. ELT was presented initially using diode lasers of 810 nm, 940 nm, and 980 nm. Recently, a 1,320-nm Nd:YAG laser was introduced for ELT. This study aims to provide mathematical modeling of ELT in order to compare 980 nm and 1,320 nm laser-induced damage of saphenous veins. Study Design/Materials and Methods The model is based on calculations describing light distribution using the diffusion approximation of the transport theory, the temperature rise using the bioheat equation, and the laser-induced injury using the Arrhenius damage model. The geometry to simulate ELT was based on a 2D model consisting of a cylindrically symmetric blood vessel including a vessel wall and surrounded by an infinite homogenous tissue. The mathematical model was implemented using the Macsyma-Pdease2D software (Macsyma, Inc., Arlington, MA). Calculations were performed so as to determine the damage induced in the intima tunica, the externa tunica and inside the peri-venous tissue for 3 mm and 5 mm vessels (considered after tumescent anesthesia) and different linear endovenous energy densities (LEED) usually reported in the literature. Results Calculations were performed for two different vein diameters: 3 mm and 5 mm and with LEED typically reported in the literature. For 980 nm, LEED: 50 to 160 J/cm (CW mode, 2 mm/second pullback speed, power: 10 W to 32 W) and for 1,320 nm, LEED: 50 to 80 J/cm (pulsed mode, pulse duration 1.2 milliseconds, peak power: 135 W, repetition rate 30 Hz to 50 Hz). Discussion and Conclusion Numerical simulations are in agreement with LEED reported in clinical studies. Mathematical modeling shows clearly that 1,320 nm, with a better absorption by the vessel wall, requires less energy to achieve wall damage. In the 810,1,320-nm range, blood plays only a minor role. Consequently, the classification of these lasers into hemoglobin-specific laser wavelengths (810, 940, 980 nm) and water-specific laser wavelengths (1,320 nm) is inappropriate. In terms of closure rate, 980 nm and 1,320 nm can lead to similar results and, as reported by the literature, to similar side effects. This model should serve as a useful tool to simulate and better understand the mechanism of action of the ELT. Lasers Surg. Med. 39:256,265, 2007. © 2007 Wiley-Liss, Inc. [source] Equalizer technology , Equal rights for disparate beadsPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 11 2010Eva-Maria Keidel Abstract One major limitation in proteomics is the detection and analysis of low-abundant proteins, i.e. in plasma. Several years ago, a technique to selectively enrich the relative concentration of low-abundant proteins was introduced by Boschetti and co-workers. It is based on a specific and saturable interaction of proteins to a high diversity of binding sites, realized by a hexapeptide library coupled to beads. This technology was commercialized as Equalizer beads or ProteoMiner. However, during application of ProteoMiner beads to plasma samples unexpected results questioned the proposed mode of action. Therefore, ProteoMiner beads were compared with chromatographic beads exhibiting completely different surface chemistry. Sepabeads FP-OD400 octadecyl, FP-DA400 diethylamine, FP-BU400 butyl, FP-HG400 hydroxyl and EXE056 epoxy were used. The results show that ProteoMiner or the different Sepabeads behave surprisingly similarly in the separation of complex protein mixtures. ProteoMiner beads interact with protein mixtures according to a general hydrophobic binding mechanism, where diversity in surface ligands plays only a negligible role. [source] Signal transduction by G-proteins, Rho-kinase and protein phosphatase to smooth muscle and non-muscle myosin IITHE JOURNAL OF PHYSIOLOGY, Issue 2 2000Andrew P. Somlyo We here review mechanisms that can regulate the activity of myosin II, in smooth muscle and non-muscle cells, by modulating the Ca2+ sensitivity of myosin regulatory light chain (RLC) phosphorylation. The major mechanism of Ca2+ sensitization of smooth muscle contraction and non-muscle cell motility is through inhibition of the smooth muscle myosin phosphatase (MLCP) that dephosphorylates the RLC in smooth muscle and non-muscle. The active, GTP-bound form of the small GTPase RhoA activates a serine/threonine kinase, Rho-kinase, that phosphorylates the regulatory subunit of MLCP and inhibits phosphatase activity. G-protein-coupled release of arachidonic acid may also contribute to inhibition of MLCP acting, at least in part, through the Rho/Rho-kinase pathway. Protein kinase C(s) activated by phorbol esters and diacylglycerol can also inhibit MLCP by phosphorylating and thereby activating CPI-17, an inhibitor of its catalytic subunit; this mechanism is independent of the Rho/Rho-kinase pathway and plays only a minor, transient role in the G-protein-coupled mechanism of Ca2+ sensitization. Ca2+ sensitization by the Rho/Rho-kinase pathway contributes to the tonic phase of agonist-induced contraction in smooth muscle, and abnormally increased activation of myosin II by this mechanism is thought to play a role in diseases such as high blood pressure and cancer cell metastasis. [source] Das Rezept als literarische Form.BERICHTE ZUR WISSENSCHAFTSGESCHICHTE, Issue 4 2003Zum multifunktionalen Gebrauch des Rezepts in der deutschen Literatur Abstract In the medical writing of antiquity the recipe, a basic form of scientific writing, was considered a literary genre with conventions of its own. In texttype-linguistics, however, the recipe plays only a minor role; in studies on the history of literary short texts it is hardly ever mentioned and, furthermore, it has come to the conclusion that the recipe's function has lain solely in the curing of the sick. The present study focuses on the its multifunctional character. A collection of widely scattered and hardly accessible recipes shows that the recipe adopted functions beyond giving technical directives. Its multifunctionality in the German literature of early modern times is manifest in medical and cooking jocular recipes, cooking recipes in minnesang, mock recipes aimed at physicians and astrologers, recipes of spiritual-religious content, recipes containing art and literary criticism as well as recipes in a moral-satirical or a political-agitative vein. [source] Investigations on the Iron-Catalyzed Asymmetric Sulfide OxidationCHEMISTRY - A EUROPEAN JOURNAL, Issue 4 2005Julien Legros Dr. Abstract The development of an enantioselective sulfide oxidation involving a chiral iron catalyst and aqueous hydrogen peroxide as oxidant is described. In the presence of a simple carboxylic acid, or a carboxylate salt, the reaction affords sulfoxides with remarkable enantioselectivities (up to 96,% ee) in moderate to good yields. The influence of the structure of the additive on the reaction outcome is reported. In the sulfoxide-to-sulfone oxidation a kinetic resolution (with s=4.8) occurs, which, however, plays only a negligible role in the overall enantioselective process. Furthermore, a positive nonlinear relationship between the ee of the product and that of the catalyst has been found. On the basis of these observations, a possible catalyst structure is proposed. [source] | |||||||||||||||||||