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Selected AbstractsThe metabolic syndrome and changing relationship between blood pressure and insulin with age, as observed in Aboriginal and Torres Strait Islander peoplesDIABETIC MEDICINE, Issue 11 2005A. E. Schutte Abstract Aims To determine the prevalence of the metabolic syndrome (MS) among Aboriginal and Torres Strait Islander peoples. A further objective was to investigate the relationships between fasting insulin and blood pressure (BP) within these groups with increasing age. Methods A cross-sectional population-based study included 369 Torres Strait Islanders (residing in Torres Strait and Far North Queensland), and 675 Aborigines from central Australia. Data necessary for classification of MS was collected, including fasting and 2-h glucose and insulin, urinary albumin and creatinine, anthropometric measurements, BP, serum lipids. Results The ATPIII criteria classified 43% of Torres Strait Islanders and 44% of Aborigines with MS, whereas 32 and 28%, respectively, had the MS according to WHO criteria. Agreement between the two criteria was only modest (kappa coefficient from 0.28 to 0.57). Factor analyses indicated no cluster including both insulin and BP in either population. Significant correlations (P < 0.05) [adjusted for gender, body mass index (BMI) and waist circumference] were observed between BP and fasting insulin: a positive correlation for Torres Strait Islanders aged 15,29 years, and an inverse correlation for Aborigines aged 40 years and older. Conclusion Torres Strait Islanders and Aborigines had very high prevalences of the MS. Specific population characteristics (high prevalences of central obesity, dyslipidaemia, renal disease) may make the WHO definition preferable to the ATPIII definition in these population groups. The poor agreement between criteria suggests a more precise definition of the metabolic syndrome that is applicable across populations is required. This study showed an inverse relationship with age for the correlation of BP and fasting insulin. [source] Guidelines for the Management of Squamous Cell Carcinoma in Organ Transplant RecipientsDERMATOLOGIC SURGERY, Issue 4p2 2004Thomas Stasko MD Background. Solid-organ transplant recipients have a high incidence of cutaneous squamous cell carcinoma (SCC) and often develop multiple and aggressive tumors. There are few published studies or reviews, which provide guidance to the clinician in the treatment of these patients. Objective. The objective was to develop useful clinical guidelines for the treatment of skin cancer in organ transplant recipients (OTRs). Methods. The members of the Guidelines Committee of the International Transplant,Skin Cancer Collaborative (ITSCC) carried out a computerized search utilizing the databases of the National Library of Medicine for reports in the literature on SCC in OTRs. These reports were collectively examined by the group and combined with experiences from the members' clinical practices in the development of the guidelines. Results. More than 300 articles relating to SCC in OTRs were reviewed. In general, reports concerning the prevention and treatment of SCC in OTRs are of individual cases or small case series. They are retrospective in nature, statistically nonrigorous, and lack the complete epidemiologic data necessary to derive definitive conclusions. Combining these studies and collective clinical experience, however, is at present the best available method for devising guidelines for the treatment of SCC in OTRs. Conclusion. Guidelines developed for the treatment of skin cancer in OTRs, supported by the best available data and collective clinical experience, may assist in the management of OTRs with SCC. The development of clinical pathways and complete documentation with rigorous prospective study is necessary to improve and refine future guideline development. [source] Occurrence and fate of micropollutants in the Vidy Bay of Lake Geneva, Switzerland.ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2010Part I: Priority list for environmental risk assessment of pharmaceuticals Abstract Pharmaceuticals are substances designed to have a biological effect in humans. Their presence in the environment, especially in surface waters, is of increasing concern because of their potential risk to non-target species. A large number of pharmaceuticals are on the market; for example, approximately 2,000 active ingredients are approved in Europe, and many of them have already been detected in surface water. It is therefore crucial to select the substances that may do the most harm to the environment prior to performing measurements and extensive risk assessment. In the present study, a method to determine a list of pharmaceuticals to survey in surface water is proposed. Inclusion of substances on the list was based on a screening procedure, the analytical feasibility, and previous knowledge of pharmaceuticals detected in water. The screening procedure proposed here is an improvement on the standard procedure of the European Medicine Evaluation Agency (EMEA). It is designed to decrease the number of pharmaceuticals to be evaluated in a stepwise manner, thus decreasing the number of data necessary for the evaluation. We applied our approach to determine a list of 37 pharmaceuticals and four hormones to survey in a specific region of Switzerland, the Lake Geneva area, and discussed the advantages and weak points of the method. Environ. Toxicol. Chem. 2010; 29:1649,1657. © 2010 SETAC [source] Kinetic uptake of bioavailable cadmium, selenium, and zinc by Daphnia magnaENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2002Ri-Qing Yu Abstract Kinetic uptake of Cd, Se(IV), and Zn by Daphnia magna from the dissolved phase was determined using radiotracer techniques in moderately hard water. The metal influx rate and distribution in the soft tissue and the exoskeleton of the daphnids as influenced by metal concentration, inorganic ligands including pH, Ca2+ and SO42,, and body size were quantified. When the metal concentrations were <180 nM for Cd and <769 nM for Zn, the concentration factor in daphnids increased linearly within the 12 h of exposure. At a higher concentration, apparent steady state was reached after 3 h of exposure. Cadmium and Zn distribution in the soft tissues was not affected by the total ambient concentrations, whereas Se distribution in the soft tissue decreased by 7 to 10% with increasing Se concentration from 16 to 643 nM. A linear positive power relationship was found between the influx rates of the metals and the ambient concentrations. The concentration factor for Se, however, decreased significantly with increasing Se concentration in water. The influx rate of metals was inversely related to the body size in a power function. When the pH in ambient water increased from 5.0 to 7.0, the influx rate of Cd, Se, and Zn increased by 2.9, 16.6, and 4.1 times, respectively. The influx rates of Cd, Se, and Zn decreased by 6.9, 8.7, and 4.4 times, respectively, with an increase in Ca2+ concentration from 0.6 to 5.1 mM. In contrast, the uptake rates of all three metals were not significantly affected by the SO42, concentration. The majority of accumulated Se was distributed in the soft tissues after 12 h of exposure, whereas Cd and Zn were about evenly distributed in the soft tissue and exoskeleton. Any changes in pH, Ca2+, and SO42, concentrations did not apparently affect their distributions in the daphnids. Our study provides important kinetic data necessary for delineating the exposure routes and for further development of the biotic ligand model in Daphnia. Using a bioenergetic-based kinetic model, we showed that the dissolved uptake is dominant for Zn accumulation (>50%). For Cd and Se, dietary exposure is dominant when the bioconcentration factors of these metals in phytoplankton are at the high end. [source] Socio-Spatial Relationships in Dairy CowsETHOLOGY, Issue 1 2010Lorenz Gygax Farm animals may serve as models for evaluating social networks in a controlled environment. We used an automated system to track, at fine temporal and spatial resolution (once per minute, ±50 cm) every individual in six herds of dairy cows (Bos taurus). We then analysed the data using social network analyses. Relationships were based on non-random attachment and avoidance relationships in respect to synchronous use and distances observed in three different functional areas (activity, feeding and lying). We found that neither synchrony nor distance between cows was strongly predictable among the three functional areas. The emerging social networks were tightly knit for attachment relationships and less dense for avoidance relationships. These networks loosened up from the feeding and lying area to the activity area, and were less dense for relationships based on synchronicity than on median distance with respect to node degree, relative size of the largest cluster, density and diameter of the network. In addition, synchronicity was higher in dyads of dairy cows that had grown up together and shared their last dry period. This last effect disappeared with increasing herd size. Dairy herds can be characterized by one strongly clustered network including most of the herd members with many non-random attachment and avoidance relationships. Closely synchronous dyads were composed of cows with more intense previous contact. The automatic tracking of a large number of individuals proved promising in acquiring the data necessary for tackling social network analyses. [source] Traffic flow continuum modeling by hypersingular boundary integral equationsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 1 2010Luis M. Romero Abstract The quantity of data necessary in order to study traffic in dense urban areas through a traffic network, and the large volume of information that is provided as a result, causes managerial difficulties for the said model. A study of this kind is expensive and complex, with many sources of error connected to each step carried out. A simplification like the continuous medium is a reasonable approximation and, for certain dimensions of the actual problem, may be an alternative to be kept in mind. The hypotheses of the continuous model introduce errors comparable to those associated with geometric inaccuracies in the transport network, with the grouping of hundreds of streets in one same type of link and therefore having the same functional characteristics, with the centralization of all journey departure points and destinations in discrete centroids and with the uncertainty produced by a huge origin/destination matrix that is quickly phased out, etc. In the course of this work, a new model for characterizing traffic in dense network cities as a continuous medium, the diffusion,advection model, is put forward. The model is approached by means of the boundary element method, which has the fundamental characteristic of only requiring the contour of the problem to be discretized, thereby reducing the complexity and need for information into one order versus other more widespread methods, such as finite differences and the finite element method. On the other hand, the boundary elements method tends to give a more complex mathematical formulation. In order to validate the proposed technique, three examples in their fullest form are resolved with a known analytic solution. Copyright © 2009 John Wiley & Sons, Ltd. [source] Accruals Management, Investor Sophistication, and Equity Valuation: Evidence from 10,Q FilingsJOURNAL OF ACCOUNTING RESEARCH, Issue 4 2002Steven Balsam The release of the full set of financial statements in Form 10,Q provides investors with the data necessary to estimate the discretionary portion of earnings, thereby allowing them to better assess the integrity of reported quarterly earnings. We thus expect a negative association between unexpected discretionary accruals estimated using 10,Q disclosures and stock returns around 10,Q filing dates. Consistent with our expectations, we document a negative association between unexpected discretionary accruals and cumulative abnormal returns over a short window around the 10,Q filing date. Furthermore, this association varies systematically with investor sophistication. Finally, results from portfolio tests indicate that this association is economically as well as statistically significant. One interpretation of our findings is that accruals management has substantial valuation consequences, which are quickly impounded into stock prices. [source] Molecular and macroscopic modeling of phase separationAICHE JOURNAL, Issue 10 2000Fernando A. Escobedo Recently proposed pseudoensemble Monte Carlo methods are extended in this work to map out diverse phase diagrams (projections of the phase-coexistence hypersurface) of multicomponent mixtures required to characterize fluid-phase equilibrium phenomena and to design separation processes. Within the pseudoensemble framework, the macroscopic models of different equilibrium processes can be readily integrated to the mathematical constraints that specify the thermodynamic state of the system. The proposed Monte Carlo methods allow, for example, the simulation of isopleths and cloud-point lines to compare experimental to simulation data and to test molecular force fields. Applications of this approach include the study of retrograde phenomena in a model natural-gas mixture through simulation of dewlines and coexistence lines at constant vaporization fraction. As demonstrated, pseudoensemble simulations can also be used to generate the thermodynamic data necessary to solve problems encountered in continuous and discontinuous distillation processes. [source] Non-phenolic radical-trapping antioxidantsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 11 2009Mario C. Foti Abstract Objectives The aim of this review article is to introduce the reader to the mechanisms, rates and thermodynamic aspects of the processes involving the most biologically relevant non-phenolic radical-trapping antioxidants. Key findings Antioxidant defences in living organisms rely on a complex interplay between small molecules and enzymes, which cooperate in regulating the concentrations of potentially harmful oxidizing species within physiological limits. The noxious effects of an uncontrolled production of oxygen- and nitrogen-centered radicals are amplified by chain reactions (autoxidations), sustained mainly by peroxyl radicals (ROO,), that oxidize and alter essential biomolecules such as lipids, lipoproteins, proteins and nucleic acids. Summary Non-phenolic antioxidants represent an important and abundant class of radical scavengers in living organisms. These compounds react with peroxyl radicals through various mechanisms: (i) formal H-atom donation from weak X-H bonds (X = O, N, S), as in the case of ascorbic acid (vitamin C), uric acid, bilirubin and thiols; (ii) addition reactions to polyunsaturated systems with formation of C-radicals poorly reactive towards O2, for example ,-carotene and all carotenoids in general; (iii) co-oxidation processes characterized by fast cross-termination reactions, for example ,-terpinene; and (iv) catalytic quenching of superoxide (O2,,) with a superoxide dismutase-like mechanism, for example di-alkyl nitroxides and FeCl3. Kinetic data necessary to evaluate and rationalize the effects of these processes are reported. The mechanisms underlying the pro-oxidant effects of ascorbate and other reducing agents are also discussed. [source] Applications of non-steady-state kinetics in physical organic chemistry: guidelines for the resolution of the kinetics of complex reaction mechanismsJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 9 2001Vernon D. Parker Abstract The resolution of the kinetics of the reversible consecutive second-order reaction mechanism involving the formation of a kinetically significant intermediate, which does not reach steady state before late in the first half-life, followed by an irreversible product-forming reaction is discussed. It is shown that an apparent second-order rate constant kapp and an extent of reaction,time profile are the only experimental data necessary for the evaluation of kf and kb (the forward and reverse rate constants) as well as kp (the microscopic rate constant for the product forming reaction). When the product-forming step involves the cleavage of a CH bond, for which there is a deuterium kinetic isotope effect on kp, the resolution of the kinetics is enhanced. In this case, the experimental data include two apparent rate constants ( and ) and two extent of reaction,time profiles, one for normal reactants and the other for isotopically substituted reactants. Under these circumstances, a unique highly resolved experimental to theoretical data fit is found that results in the evaluation of all four microscopic rate constants: and . An alternative, when a kinetic isotope effect is not involved, is to fit the extent of reaction,time profiles for two or more concentrations of reactants concurrently. This procedure results in the resolution of the three microscopic rate constants for the reaction. Copyright © 2001 John Wiley & Sons, Ltd. [source] Combining Microarray-based Genomic Selection (MGS) with the Illumina Genome Analyzer Platform to Sequence Diploid Target RegionsANNALS OF HUMAN GENETICS, Issue 5 2009David T. Okou Summary Novel methods of targeted sequencing of unique regions from complex eukaryotic genomes have generated a great deal of excitement, but critical demonstrations of these methods efficacy with respect to diploid genotype calling and experimental variation are lacking. To address this issue, we optimized microarray-based genomic selection (MGS) for use with the Illumina Genome Analyzer (IGA). A set of 202 fragments (304 kb total) contained within a 1.7 Mb genomic region on human chromosome X were MGS/IGA sequenced in ten female HapMap samples generating a total of 2.4 GB of DNA sequence. At a minimum coverage threshold of 5X, 93.9% of all bases and 94.9% of segregating sites were called, while 57.7% of bases (57.4% of segregating sites) were called at a 50X threshold. Data accuracy at known segregating sites was 98.9% at 5X coverage, rising to 99.6% at 50X coverage. Accuracy at homozygous sites was 98.7% at 5X sequence coverage and 99.5% at 50X coverage. Although accuracy at heterozygous sites was modestly lower, it was still over 92% at 5X coverage and increased to nearly 97% at 50X coverage. These data provide the first demonstration that MGS/IGA sequencing can generate the very high quality sequence data necessary for human genetics research. All sequences generated in this study have been deposited in NCBI Short Read Archive (http://www.ncbi.nlm.nih.gov/Traces/sra, Accession # SRA007913). [source] Investigation of the Development of Conflagration of Solid Material via Analysis of Coupled Heat, Mass and Momentum TransportCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 2 2009U. Krause Abstract A mathematical model is presented for the transport of heat, mass and momentum transfer through a porous medium to simulate the chain of events from self-heating, subsequent self-ignition to smouldering fire propagation and burn-out of combustible fractions. The model comprises both diffusive and convective transport. The chemical reaction sub-model includes solid fuel decomposition and the combustion of char, carbon monoxide and hydrogen. Furthermore, biological processes, which may be a precursor of self-heating and vaporization/condensation of moisture, are also included into the model. All input data necessary for implementing the model have been determined experimentally. The model has been validated against laboratory scale self-ignition and smouldering propagation experiments and then applied to predictions of different fire scenarios during storage of bulk materials. [source] | ||||||||||||||||