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Selected AbstractsThe source process of the 2001 July 26 Skyros Island (Greece) earthquakeGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 3 2004Zafeiria Roumelioti SUMMARY The spatial and temporal distribution of slip during the 2001 July 26 Skyros (Greece) earthquake Moment magnitude (M 6.5) is investigated using broadband data recorded at regional distances. The applied method involves estimation of the source time functions of the examined event through an empirical Green's function approach and inversion of their shapes to estimate kinematic source parameters. Our test inversions to statistically identify the fault plane, together with the distribution of aftershocks clearly indicate sinistral strike-slip faulting. In view of the fact that the Skyros epicentre lies near the western termination of the dextral strike-slip North Anatolian Fault (NAF) into the Aegean Sea, this sinistral strike-slip motion, for the first time instrumentally identified, has great tectonic significance. The best values searched through the inversion are 0.7 s for the rise time, and 2.4 km s,1 for the rupture velocity. Most of the slip appears to be concentrated in a relatively small area around the hypocentre, while a smaller slip patch was found at relatively large depth (18,24 km). At least two of the large aftershocks following the main event also occurred at the deeper part of the fault. Smaller amounts of slip are distributed in a wider area with dimensions similar to those inferred from the aftershock distribution studies and the empirical relations applicable to Greece. [source] Hydrogen and oxygen isotopes of water from inclusions in minerals: design of a new crushing system and on-line continuous-flow isotope ratio mass spectrometric analysisRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 17 2009Yuri V. Dublyansky An analytical line for stable isotope analyses of water recovered from fluid inclusions in minerals was built and successfully tested. The line is based on the principle of continuous-flow analysis of water via high-temperature reduction on glassy carbon. It includes a custom-designed set of high-efficiency crushers and a cryo-focusing cell. This paper provides details of the line design and discusses strategies for line conditioning and mitigation of memory effects. The line allows measurements of hydrogen and oxygen isotopes during a single acquisition. The precision of the analyses depends on the amount of water released from the inclusions. The best results are obtained for samples containing at least 0.1,0.2,µL (0.06,0.11,µmol) H2O. For such samples precision is better than 1.5, for ,D and 0.5, for ,18O (1,). Smaller amounts of water can be measured but at lower precision. Analyses of modern calcite formed under stable conditions in a deep cave allowed assessment of the accuracy of the analyses. The ,D values measured in fluid inclusions of this working standard match the ,D value of the parent water, and the oxygen isotope values agree within ca. 0.5,. This indicates that fluid inclusions trapped in calcite at near-ambient temperatures (e.g. speleothems and low-temperatures phreatic calcite) faithfully preserve the original isotopic composition of the parent waters. Copyright © 2009 John Wiley & Sons, Ltd. [source] Augmentation of a nearest neighbour clustering algorithm with a partial supervision strategy for biomedical data classificationEXPERT SYSTEMS, Issue 1 2009Sameh A. Salem Abstract: In this paper, a partial supervision strategy for a recently developed clustering algorithm, the nearest neighbour clustering algorithm (NNCA), is proposed. The proposed method (NNCA-PS) offers classification capability with a smaller amount of a priori knowledge, where a small number of data objects from the entire data set are used as labelled objects to guide the clustering process towards a better search space. Experimental results show that NNCA-PS gives promising results of 89% sensitivity at 95% specificity when used to segment retinal blood vessels, and a maximum classification accuracy of 99.5% with 97.2% average accuracy when applied to a breast cancer data set. Comparisons with other methods indicate the robustness of the proposed method in classification. Additionally, experiments on parallel environments indicate the suitability and scalability of NNCA-PS in handling larger data sets. [source] Flammability studies of sodium thiosulphate or metabisulphite impregnated wood using cone calorimeterFIRE AND MATERIALS, Issue 2 2007imkovic Abstract Spruce wood boards impregnated with Na2S2O3 or Na2S2O5 were studied with the cone calorimeter. The presence of Na2S2O3 lowered the average heat release rate in comparison to untreated material. The total amounts of CO and CO2 production were reduced by the treatment and also the specific extinction area and mass loss rate decreased. Washing of the salt from the material with water caused partial loss of the properties. Addition of the second impregnation step using acids (HCOOH, H3BO3 or H3PO4) resulted in the fixation of the sulphur in wood, but gave not the results of single-step modification for thiosulphate. With Na2S2O5 and without acid, the CO and time-to-ignition values were higher and average heat release rate smaller in comparison to unmodified material. Combined one step Na2S2O5/H3BO3 treatment lowered the CO, CO2 and specific extinction area values in comparison to the modification with Na2S2O5, similarly like it was observed for Na2S2O3/H3BO3 two-step-treatment. According to time-to-ignition values, Na2S2O5 alone at 5% addition is a better flame retardant than Na2S2O3 at 7%, but the effect is diminished at 10% amount or presence of acids. The total smoke release curves showed decrease due to modification in both phases of the process. Introduction of water washing as well as the acid treatment further lowered the values. The best results were achieved with 15% Na2S2O3,2% H3PO4,H2O system. According to the total smoke release curve the specimen produced more than five times smaller amount of smoke than untreated material in the first phase of the process. It seams that the concentration of Na2S2O5 is less affecting the properties than the synergistic effect of the Na2S2O3 or Na2S2O5/H3BO3 system. Although the level of smoke is low, the presence of elemental sulphur causes smaller times-to-ignition than on starting material. Copyright © 2006 John Wiley & Sons, Ltd. [source] Essential oil constituents of Melia dubia, a wild relative of Azadirachta indica growing in the Eastern Ghats of Peninsular IndiaFLAVOUR AND FRAGRANCE JOURNAL, Issue 4 2001M. A. H. Nagalakshmi Abstract The leaf essential oil of Melia dubia Cav. (Meliaceae) has been studied by GC,MS. The leaf essential oil consists chiefly of monoterpenes (35.71%) and oxygenated monoterpenes (27.98%), accompanied by a relatively much smaller amount of alkanes (11.17%), sesquiterpene hydrocarbons (9.26%) and phenylpropanoids (3.90%). The monoterpene camphene occurs as a major constituent (21.68%) of this leaf essential oil. It is accompanied by a noticeable amount of ,- and ,-pinene (3.12% and 5.13%, respectively) and a much smaller amount of sabinene (2.75%). The oxygenated monoterpenes are distinctly dominated by the presence of the bicyclic ketone camphor (17.85%), while iso-borneol and borneol are detected in much smaller amounts (4.15% and 1.12%, respectively). Copyright © 2001 John Wiley & Sons, Ltd. [source] Palaeomagnetic evidence for the Gondwanian origin of the Taurides and rotation of the Isparta Angle, southern TurkeyGEOLOGICAL JOURNAL, Issue 4 2002John D. A. Piper Abstract The Taurides, the southernmost of the three major tectonic domains that constitute present-day Turkey, were emplaced following consumption of the Tethyan Ocean in Late Mesozoic to mid-Tertiary times. They are generally assigned an origin at the northern perimeter of Gondwana. To refine palaeogeographic control we have investigated the palaeomagnetism of a range of Jurassic rocks. Forty-nine samples of Upper Jurassic limestones preserve a dual polarity remanence (D/I=303/,9°, ,95=6°) interpreted as a primary magnetization acquired close to the equator and rotated during emplacement of the Taurides. Result from mid-Jurassic dolerites confirm a low palaeolatitude for the Tauride Platform during Jurassic times at the Afro,Arabian sector of Gondwana. Approximately 4000,km of Tethyan closure subsequently occurred between Late Jurassic and Eocene times. Although related Upper Jurassic limestones and Liassic redbeds preserve a sporadic record of similar remanence, the dominant signature in these latter rocks is an overprint of probable mid-Miocene age, probably acquired during a single polarity chron and imparted by migration of a fluid front during nappe loading. This is now rotated consistently anticlockwise by c. 30° and conforms to results of previous studies recording bulk Neogene rotation of the Isparta region following Lycian nappe emplacement. The regional distribution of this overprint implies that the Isparta Angle (IA) has been subject to only small additional closure (<10°) since Late Miocene time. A smaller amount (c. 6°) of clockwise rotation within the IA since Early Pliocene times is associated with an ongoing extensional regime and reflects an expanding curvature of the Tauride arc produced by southwestward extrusion of the Anatolian collage as a result of continuing northward motion of Afro,Arabia. Copyright © 2002 John Wiley & Sons, Ltd. [source] Effect of the plate thermal resistance on the heat transfer performance of a corrugated thin plate heat exchangerHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 3 2006Hiroshi Iwai Abstract Two-dimensional conjugate conduction/convection numerical simulations were carried out for flow and thermal fields in a unit model of a counter-flow-type corrugated thin plate heat exchanger core. The effects of the thermal resistance of the solid plate, namely the variation of the plate thickness and the difference of the plate material, on the heat exchanger performance were examined in the Reynolds number range of 100 Highly Efficient Direct Carboxylation of Propane into Butyric Acids Catalyzed by Vanadium ComplexesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2007Marina Abstract A direct and highly efficient carboxylation of propane by carbon monoxide into butyric acids (mainly isobutyric and, in a smaller amount, n -butyric), in the presence of potassium peroxodisulphate (K2S2O8) and in trifluoroacetic acid solution, has been achieved by using a vanadium catalytic system based on Ca[V{ON(CH(CH3)COO)2}2] (synthetic amavadine), its model compounds Ca[V{ON(CH2COO)2}2] or [VO{N(CH2CH2O)3}] , other simpler vanadium compounds, such as [VO(acac)2] or VOSO4, are less active. Overall yields (based on propane) of carboxylic acids up to 70,% and TON values up to 18.4×103 have been reached. The effects of various factors such as the propane and carbon monoxide pressures, temperature, time, catalyst amount and radical traps have been investigated, the reactions are shown to proceed via both C - and O -centred radicals, with K2S2O8 playing the role of an oxidant via a free radical mechanism. [source] Aspects of the modelling of the radial distribution function for small nanoparticlesJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 6 2007Vladimir I. Korsunskiy An approach to modelling radial distribution functions (RDFs) of nanoparticle samples over a wide range of interatomic distances is presented. Two different types of contribution to the model RDF are calculated. The first explicitly reflects the structure of the nanoparticle parts with more or less crystalline atomic structure. It can be calculated precisely and contains comparatively sharp peaks, which are produced by the set of discrete interatomic distances. The second includes RDF contributions from distances between weakly correlated atoms positioned within different nanoparticles or within different parts of a nanoparticle model. The calculation is performed using the approximation of a uniform distribution of atoms and utilizes the ideas of the characteristic functions of the particle shape known in small-angle scattering theory. This second RDF contribution is represented by slowly varying functions of interatomic distance r. The relative magnitude of this essential part of the model RDF increases with increasing r compared with the part that represents the ordered structure. The method is applied to test several spherical and core/shell models of semiconductor nanoparticles stabilized with organic ligands. The experimental RDFs of ZnSe and CdSe/ZnS nanoparticle samples were obtained by high-energy X-ray diffraction at beamline BW5, HASYLAB, DESY. The ZnSe nanoparticles have a spherical core with approximately 26,Å diameter and zincblende structure. The RDF of the CdSe/ZnS nanoparticle sample shows resolved peaks of the first- and the second-neighbour distances characteristic for CdSe (2.62 and 4.27,Å) and for ZnS (2.33 and 3.86,Å) and for the first time clearly confirms the presence of CdSe and ZnS nanophases in such objects. The diameters of the CdSe and ZnS spherical cores are estimated as 27 and 15,Å. CdSe and ZnS are present in the sample for the most part as independent nanoparticles. A smaller amount of ZnS forms an irregularly shaped shell around the CdSe cores, which consists of small independently oriented ZnS particles. [source] Contrast analysis of the composition of ribosomes extracted with different purification proceduresJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2000Giuseppe Briganti The composition and hydration of E. coli ribosomes isolated with different purification protocols has been analysed by combining two experimental techniques: measurements of small-angle neutron scattering (SANS), for two different isotopic solvent compositions, and refractive index (RI) increments. From the contrast between the solvent and solute scattering densities and the molar polarizability, determined experimentally with SANS and RI measurements, three independent equations are obtained and three unknown quantities are determined: (i) the volume of the solute hydrated skeleton Vs, (ii) the material contained in it, namely the biological components, intrinsic (rRNA and proteins) and extrinsic, such as aminoacylsynthetase and elongation factors, (iii) the number of water molecules structurally bound to the ribosome and non-exchangeable with the solvent. From the form factor at infinite contrast, a second definition of the solute volume is obtained, , which represents the volume within the contour surface of the ribosome. This value is generally larger than Vs and can include a certain amount of water molecules, i.e. those inside the volume (,Vs). Considering the molar volume of this water to be equal to that of the bulk water, it is possible to evaluate its amount. The particle density calculated from the ribosome components in , including proteins, RNA, bound and unbound water molecules, corresponds to the buoyant density measured for E. coli 70S particles. The two ribosomal preparations display different performances in protein synthesis; hence the results indicate that the optimal condition corresponds to a wider skeleton and contour volume but containing a smaller amount of segregated water molecules. It is believed that the method provides a reliable technique to determine the composition of ribosomes under various experimental conditions. [source] Palliation in cancer of the oesophagus , what passes down an oesophageal stent?JOURNAL OF HUMAN NUTRITION & DIETETICS, Issue 5 2003A. Holdoway Introduction: Self-expanding metal stents are becoming an increasingly popular method of palliation of dysphagia in advanced oesophageal carcinoma. Approximately 10% require intervention post-placement because of blockage (Angorn, 1981). This could be prevented by effective dietary advice. We set out to write evidence-based dietary guidelines for patients undergoing oesophageal stent insertion. A comprehensive literature search failed to identify evidence to support the present guidelines used by manufacturers and dietitians on foods allowed or to avoid and the use of fizzy drinks to ,clean' the stent. Only reference on the ability to consume a semi-solid or solid diet was made (Nedin, 2002). We therefore tested the ability of 50 foods to pass through a stent and the efficacy of fizzy water in unblocking an occluded stent. Method: Normal mouthfuls of raw and cooked, peeled/unpeeled fruit and vegetables, casseroles, griddle or grilled plain meat, poultry or fish, eggs, nuts, dried fruit and bread in various forms were tested. An adult female chewed a ,normal' mouthful of each test food and at the point of swallowing the bolus of food was passed into an expanded Ultraflex metal covered stent (internal diameter 18 mm). If occlusion occurred, water was dribbled through the stent, simulating swallowing fluid, in an attempt to unblock the stent. If the occlusion remained, the stent was agitated to mimic advice given about moving around to unblock a stent in a patient. If it remained occluded, a smaller amount of food, approximately half a mouthful, was chewed for twice as long and re-tested. To test the efficacy of fizzy water to clear an occlusion, we compared the ability of water, warm water and fizzy water to unblock a stent artificially occluded with a bolus of bread. Results: Foods that occluded the stent but passed through if eaten in half mouthfuls and chewed for twice normal chewing time included sandwiches, dry toast, apple, tinned pineapple, fresh orange segments with pith removed, up to six sultanas, chopped dried apricot, boiled egg, muesli, meat and poultry. Dry meat, fruit with pith, skins of capsicum peppers and tomatoes, more than seven sultanas and dried apricots caused occlusion. Nuts and vegetables such as lettuce, which are cited in many diet sheets as items to avoid (Nedin, 2002), passed through the stent when chewed to a normal level. The volumes of fluid required to unblock a stent occluded with bread were 5 l of fizzy water, 3.5 l of cold water or 1 l of warm water. Conclusion: If a patient has good dentition and can chew well and take small mouthfuls and prepare and cook food appropriately, it is likely that they can enjoy a wide variety of solid foods. The use of fizzy drinks to maintain the patency of the stent in patients prone to reflux is questionable, warm fluids may be more efficacious. Based on these initial findings we are updating our dietary guidelines for patients undergoing oesophageal stent insertion and hope to audit stent occlusion following implementation. [source] Difference in non-weight-bearing effects on bone mineral density between trunk and peripheral fat mass in women with polycystic ovary syndromeJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 2 2010Yumi Yanazume Abstract Aim:, To investigate the difference in non-weight-bearing effects on bone mineral density (BMD) between trunk and peripheral fat mass in women with polycystic ovary syndrome (PCOS). Methods:, Subjects were 123 amenorrheic PCOS women with right side dominance. Age, height, body weight, and body mass index were recorded. Trunk, peripheral (extremities), trunk,leg fat ratio as an index of body fat distribution, left arm (non-weight-bearing site) lean mass and BMD were measured by dual-energy X-ray absorptiometry. Serum testosterone and estradiol levels were measured. Relationships of BMD with trunk, peripheral fat mass, and sex hormones levels were investigated. Results:, Trunk fat mass amount was 9.8 ± 6.7 kg and was lower than the peripheral fat mass amount (12.2 ± 4.4 kg, P < 0.01). On Pearson's correlation test, trunk fat mass and left arm lean mass were positively correlated with arm BMD (r = 0.359, P < 0.001 and r = 0.501, P < 0.0001, respectively), while peripheral fat mass and serum testosterone levels were not correlated with BMD (r = 0.083 and 0.114, respectively, NS). On multiple regression analysis, trunk fat mass was positively correlated with BMD (t -value = 3.465; P < 0.001), independent of age and height. However, this relationship disappeared after additionally adjusting for left arm lean mass. Conclusion:, Trunk fat mass, despite the smaller amount, is more associated with arm BMD than peripheral fat mass is through its non-weight-bearing effects. [source] Tailoring viscoelastic and mechanical properties of the foamed blends of EVA and various ethylene-styrene interpolymersPOLYMER COMPOSITES, Issue 3 2003I-Chun Liu Foamed materials (EVA/ESI) have been prepared from blends of ethylene-vinyl acetate copolymer (EVA) and ethylene-styrene interpolymers (ESI) in the presence of various amounts of dicumyl peroxide (DCP). Four ESIs of different compositions were employed in this study; their styrene contents ranged from 30 to 73 wt% and their Tg ranged from ,2 to 33°C. It has been found that microcellular morphology, degree of crosslinking and expansion ratio were strongly affected by the DCP concentration and the type of ESI employed. A minimum degree of crosslinking was required for making good foams and the same degree of crosslinking could be achieved by employing a smaller amount of DCP for an EVA/ESI blend having a higher styrene content. In contrast to other EVA blends, such as EVA/LDPE, these EVA/ESI blends exhibited no existence of any optimum DCP concentration, and the , glass transition temperatures of the foams varied with the ESI type, covering a wide span from 0°C to 37°C. Therefore, it was possible to tailor the Tg of an EVA/ESI blend by choosing an appropriate type of ESI. Furthermore, by correctly tailoring the Tg, the EVA/ESI foam could be made into a rubbery material with a custom-designed damping factor. Tensile strength and modulus of the EVA/ESI foams increased generally with an increase in the styrene content, with the exception that ESIs with very low styrene content will confer on the blend a high modulus at small strain and a large elongation at break. [source] Prediction-based estimating functionsTHE ECONOMETRICS JOURNAL, Issue 2 2000Michael Sørensen A generalization of martingale estimating functions is presented which is useful when there are no natural or easily calculated martingales that can be used to construct a class of martingale estimating functions. An estimating function of the new type, which is based on linear predictors, is called a prediction-based estimating functions. Special attention is given to classes of prediction-based estimating functions given by a finite-dimensional space of predictors. It is demonstrated that such a class of estimating functions has most of the attractive properties of martingale estimating functions. In particular, a simple expression is found for the optimal estimating function. This type of prediction-based estimating functions only involve unconditional moments, in contrast to the martingale estimating functions where conditional moments are required. Thus, for applications to discretely observed continuous time models, a considerably smaller amount of simulation is, in general, needed for these than for martingale estimating functions. This is also true of the optimal prediction-based estimating functions. Conditions are given that ensure the existence, consistency and asymptotic normality of the corresponding estimators. The new method is applied to inference for sums of Ornstein,Uhlenbeck-type processes and stochastic volatility models. Stochastic volatility models are studied in considerable detail. It is demonstrated that for inference about models by Hull and White and Chesney and Scott, an explicit optimal prediction-based estimating function can be found so that no simulations are needed. [source] The effect of anthropogenic habitat usage on the social behaviour of a vulnerable species, Cyclura nubilaANIMAL CONSERVATION, Issue 1 2003Kathryn E. Lacy With the increasing human population world-wide, animals and humans are sharing more habitat. In this study, we consider the consequences of this habitat usage overlap on the behaviour patterns and social structure of a threatened species. Specifically, we used focal animal samples to collect data on the Cuban rock iguana, Cyclura nubila, in six field sites. Three of these sites are subject to considerable anthropogenic habitat usage, whereas three are in relatively low anthropogenic usage areas. Individuals in high anthropogenic usage sites were more closely assembled, with more males and females sharing a smaller amount of space. These animals exhibited even more aggressive behaviour and social interactions than expected when taking into account the larger number of possible interactants. High anthropogenic usage sites also had more male,male interactions and fewer males interacting with females. We suggest that social and mating system changes have occurred. Ramifications of these recent changes in the behavioural repertoires on the long-term survival of the species are discussed. [source] Highly efficient bimetallic iron-palladium catalyzed Michael-type Friedel,Crafts reactions of indoles with chalconesAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 3 2009Yue-Hua Gao Abstract Iron,palladium is a superior bimetallic catalyst in the presence of acetylacetone (Acac) with remarkable synergistic effect for the Michael-type Friedel,Crafts reactions of indoles with chalcones. This catalytic system has the advantages of mild reaction conditions, smaller amount of metal salts, high yields of the desired products and operational simplicity, which make it a useful and promising process for the synthesis of indole derivatives. Copyright © 2009 John Wiley & Sons, Ltd. [source] Changing risk factors for fluorosis among South Australian childrenCOMMUNITY DENTISTRY AND ORAL EPIDEMIOLOGY, Issue 3 2008A. John Spencer Abstract,,, Background:, Research in the last decade has shown changing exposure patterns to discretionary fluorides and declining prevalence of fluorosis among South Australian children, raising the question of how risk factors for fluorosis have changed. Objective:, To examine and compare risk factors for fluorosis among representative samples of South Australian children in 1992/1993 and 2002/2003. Methods:, Similar sampling strategies and data collection methods were employed in the Child Fluoride Study (CFS) Marks 1 (1992/1993) and 2 (2002/2003). Participants in each CFS round were examined for fluorosis using the Thylstrup and Fejerskov (TF) Index. Exposure history was collected for fluoride in water, toothpaste, fluoride supplements and infant formula, allowing for a fluorosis risk assessment analysis. Data were re-weighted to represent the child population at each time. Changes in prevalence of fluorosis, defined as having a TF score of 1+ on maxillary central incisors, fluoride exposure and risk factors between the two rounds were evaluated. Result:, A total of 375 and 677 children participated in the 1992/1993 and 2002/2003 rounds respectively. Prevalence of fluorosis declined significantly from 45.3% to 25.9%. Reduced use of fluoride supplements and increased use of 400,550-ppm children F toothpaste were the most substantial fluoride exposure changes. Early toothpaste use, residence in fluoridated areas and fluoride supplement use were the risk factors in 1992/1993. Early toothpaste use and fluoride supplement use were not risk factors, leaving fluoridated water as the only risk factor among the common variables in 2002/2003. In an analysis stratified by the type of fluoridated toothpaste in 2002/2003, the large amount of toothpaste used was a risk factor in those who used 1000-ppm fluoridated toothpaste, and eating/licking toothpaste when toothpaste use started was a risk factor among children who used either 1000-ppm or 400,550-ppm fluoridated toothpaste. Conclusion:, Introduction of the 400,550-ppm F toothpaste and use of smaller amount of toothpaste restricted risk associated with early toothpaste use. Less use and possibly a stricter fluoride supplements regimen also restricted fluorosis risk. Periodic monitoring of risk of fluorosis is required to adjust guidelines for fluoride use in caries prevention. [source] Occurrence of toxic cyanobacterial blooms in San Roque Reservoir (Córdoba, Argentina): A field and chemometric studyENVIRONMENTAL TOXICOLOGY, Issue 3 2003María Valeria Amé Abstract We evaluated the presence of cyanobacterial blooms in San Roque Reservoir (Córdoba, Argentina). Cyanobacterial blooms and water samples were collected over 4 years (1998,2002). We confirmed the presence of microcystin-LR and microcystin-RR in 97% of these blooms. The total amount of microcystin (MC) ranged between 5.8 and 2400.0 ,g g,1 of freeze-dried bloom material. These values suggest that guidelines for safe water consumption and recreational use should be established for this reservoir. Twenty-eight physical and chemical parameters were measured in water samples and evaluated by discriminant analysis (DA). A first DA was used to evaluate the factors promoting cyanobacteria occurrence, identifying nine parameters following three patterns associated with cyanobacterial growth. Inorganic phosphorous was found to promote the presence of blooms, whereas the highest proliferation of cyanobacteria was observed in the presence of smaller amounts of carbonate, bicarbonate, sulfate, and fecal coliform bacteria. The results observed during our fieldwork, analyzed using DA, agreed with the results of other laboratory studies, thus confirming the usefulness of DA to help with the evaluation of a complicated environmental data matrix. A second DA, using only water samples collected during the presence of cyanobacteria blooms, identified another nine parameters. The analysis of these parameters allowed us to identify certain environmental factors that could lead to the dominance of toxic strains, thus increasing the amount of MC. The results showed that, in our case, an increase in the water temperature was associated with higher amounts of MC per dry weight unit, whereas an increase in the concentrations of ammonia,nitrogen and iron were associated with lower amounts of MC, thus disfavoring the dominance of toxic strains. © 2003 Wiley Periodicals, Inc. Environ Toxicol 18: 192,201, 2003. [source] Asymmetric Information and Dividend PolicyFINANCIAL MANAGEMENT, Issue 4 2008Kai Li We examine how informational asymmetries affect firms' dividend policies. We find that firms that are more subject to information asymmetry are less likely to pay, initiate, or increase dividends, and disburse smaller amounts. We show that our main results are not driven by our sample and that our results persist after accounting for the changing composition of payout over the sample period, the increasing importance of institutional shareholdings, and catering incentives. We conclude that there is a negative relation between asymmetric information and dividend policy. Our results do not support the signaling theory of dividends. [source] Essential oil constituents of Melia dubia, a wild relative of Azadirachta indica growing in the Eastern Ghats of Peninsular IndiaFLAVOUR AND FRAGRANCE JOURNAL, Issue 4 2001M. A. H. Nagalakshmi Abstract The leaf essential oil of Melia dubia Cav. (Meliaceae) has been studied by GC,MS. The leaf essential oil consists chiefly of monoterpenes (35.71%) and oxygenated monoterpenes (27.98%), accompanied by a relatively much smaller amount of alkanes (11.17%), sesquiterpene hydrocarbons (9.26%) and phenylpropanoids (3.90%). The monoterpene camphene occurs as a major constituent (21.68%) of this leaf essential oil. It is accompanied by a noticeable amount of ,- and ,-pinene (3.12% and 5.13%, respectively) and a much smaller amount of sabinene (2.75%). The oxygenated monoterpenes are distinctly dominated by the presence of the bicyclic ketone camphor (17.85%), while iso-borneol and borneol are detected in much smaller amounts (4.15% and 1.12%, respectively). Copyright © 2001 John Wiley & Sons, Ltd. [source] Ethanol and Acetaldehyde Adsorption on a Carbon-Supported Pt Catalyst: A Comparative DEMS StudyFUEL CELLS, Issue 1-2 2004H. Wang Abstract The adsorption of ethanol and acetaldehyde on carbon Vulcan supported Pt fuel cell catalyst and the electrochemical desorption of the adsorption products were studied, using electrochemical measurements and differential electrochemical mass spectrosmetry (DEMS), under continuous flow conditions. Faradaic current adsorption transients at different constant adsorption potentials, which also include CO adsorption for comparison, show pronounced effects of the adsorption potential and the nature of the reactant molecule. Acetaldehyde adsorption is much faster than ethanol adsorption at all potentials. Pronounced Had induced blocking effects for ethanol adsorption are observed at very cathodic adsorption potentials, < 0.16,V, while for acetaldehyde adsorption this effect is much less significant. Comparison of the adsorption charge for CO adsorption with the H-upd charge allows differentiation between H-displacement and double-layer charging effects. Continuous bulk oxidation is observed for both reactants at potentials > 0.31,V; for acetaldehyde adsorption, increasing bulk reduction is found at low potentials. Based on the electron yield per CO2 molecule formed and on the similarity with the CO stripping characteristics the dominant stable adsorbate is CO, coadsorbed with smaller amounts of (partly oxidized) hydrocarbon decomposition fragments, which are also oxidized at higher potentials (> 0.85,V) and which can be reductively desorbed as methane or, to a very small extent, as ethane. The presence of small amounts of adsorbed C2 species and the oxidative dissociation of these species in the main CO oxidation potential range is clearly demonstrated by increased methane desorption after a potential shift to 0.85,V. The data demonstrate that the Pt/Vulcan catalyst is very reactive for C-C bond breaking upon adsorption of these reactants. [source] Pb, Nd, and Sr isotopic constraints on the origin of Miocene basaltic rocks from northeast Hokkaido, Japan: Implications for opening of the Kurile back-arc basinISLAND ARC, Issue 2 2000Yasuo Ikeda Abstract Late Miocene (7,9 Ma) basaltic rocks from the Monbetsu-Kamishihoro graben in northeast Hokkaido have chemical affinities to certain back-arc basin basalts (referred to herein as Hokkaido BABB). Pb-, Nd- and Sr-isotopic compositions of the Hokkaido BABB and arc-type volcanic rocks (11,13 Ma and 4,4.5 Ma) from the nearby region indicate mixing between the depleted mantle and an EM II-like enriched component (e.g. subducted pelagic sediment) in the magma generation. At a given 87Sr/86Sr, Hokkaido BABB have slightly lower 143Nd/144Nd and slightly less radiogenic 206Pb/204Pb compared with associated arc-type lavas, but both these suites are difficult to distinguish solely on the basis of isotopic compositions. These isotopic data indicate that while generation of the Hokkaido BABB involves smaller amounts of the EM II-like enriched component than do associated arc lavas, Hokkaido BABB are isotopically distinct from basalts produced at normal back-arc basin spreading centers. Instead, northeast Hokkaido BABB are more similar to basalts erupted during the initial rifting stage of back-arc basins. The Monbetsu-Kamishihoro graben may have developed in association with extension that formed the Kurile Basin, suggesting that opening of the basin continued until late Miocene (7,9 Ma). [source] Analysis of nutritive sucking function in very low and extremely low birthweight infants in Japan: A pilot studyJAPAN JOURNAL OF NURSING SCIENCE, Issue 1 2005Manami MATSUBARA Abstract Aim:, The purpose of the present study was to investigate the differences in nutritive sucking patterns between very low, extremely low birth-weight infants (LBWI) and full-term infants (FTI) and to examine the change in those sucking patterns within 5 months after birth. Methods:, Sucking patterns of eight LBWI and seven FTI were compared. In addition, sucking patterns were measured in four of the LBWI and seven of the FTI until 5 months of age to determine change in sucking wave patterns over time. Results:, During the first month after birth, there was a significant difference in the sucking wave between the LBWI and FTI. The sucking cycle time was significantly shorter and the intensity of the sucking pressure was significantly smaller in the LBWI than that in the FTI. By 5 months, significant correlations were noted between the actual age or the modified age and the sucking pressure in both LBWI and FTI. Conclusions:, The findings suggest that the weakness of oral muscular function and less sucking skill can bring about the weakness of intensity of sucking pressure, decreased time of the sucking stage in a sucking cycle, and unstable intensity of sucking pressure and time of the sucking stage in LBWI infants, causing low efficiency of milk intake and smaller amounts of milk swallowing during each sucking period as they obstructs the development of oral muscular function itself. These problems last for a longer period of time in LBWI than in FTI, leading to a deficit in the development of masticatory function in LBWI. The results of the current pilot study will serve as a foundation to investigate the development of masticatory function in LBWI as they grow into early childhood. [source] Changes in vasoactive intestinal peptide in gingival crevicular fluid in response to periodontal treatmentJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 6 2002Gerard J. Linden Abstract Aims: To evaluate the role of the anti-inflammatory neuropeptide vasoactive intestinal peptide (VIP) in periodontal health and disease and to determine the effects of periodontal treatment, resulting in a return to periodontal health, on the levels of VIP in gingival crevicular fluid (GCF). Methods: At baseline, 10 subjects with periodontitis (nine females, one male, mean age 43.0, SD 7.3) started a course of non-surgical periodontal treatment. Clinical indices were measured at one periodontitis and one clinically healthy site at an initial visit and at 8 weeks after the completion of treatment in each subject. A 30-s sample of GCF was collected from each test site using perio paper strips. The volume of GCF was measured and each sample subsequently analysed for VIP by radioimmunoassay. One healthy site was sampled from each member of a control group (10 females, mean age 29.9, SD 8.2 years) with clinically healthy gingiva and no periodontitis. Results: The clinical condition of all periodontitis sites improved as a result of periodontal treatment. The levels of VIP (pg/30 s sample) in periodontitis-affected sites fell significantly from 302.0 (SD 181.2) at the initial visit to 78.0 (54.4) after treatment, p = 0.007. The reduction in the concentration of VIP (pg/µL) in GCF from 524.3 (322.3) to 280.8 (280.2) was not statistically significant. The levels of VIP in clinically healthy sites fell from 115.5.5 (74.3) to 77.8 (32.3), n.s. and the concentration changed little from 883.8 (652.1) to 628.7 (323.3), n.s. There were substantially smaller amounts of VIP (25.8, SD 12.8) pg in healthy sites sampled from control subjects. Conclusions: VIP is present in GCF in greater quantities in periodontitis-affected than clinically healthy sites. In addition, the reduction in inflammation resulting from effective periodontal treatment is associated with a reduction in the levels of VIP in gingival crevicular fluid. [source] Identification of phenylethanolamine N -methyltransferase gene expression in stellate ganglia and its modulation by stressJOURNAL OF NEUROCHEMISTRY, Issue 5 2006L. Kubovcakova Abstract Phenylethanolamine N -methyltransferase (PNMT, EC 2.1.1.28) is the terminal enzyme of the catecholaminergic pathway converting noradrenaline to adrenaline. Although preferentially localized in adrenal medulla, evidence exists that PNMT activity and gene expression are also present in the rat heart, kidney, spleen, lung, skeletal muscle, thymus, retina and different parts of the brain. However, data concerning PNMT gene expression in sympathetic ganglia are still missing. In this study, our effort was focused on identification of PNMT mRNA and/or protein in stellate ganglia and, if present, testing the effect of stress on PNMT mRNA and protein levels in this type of ganglia. We identified both PNMT mRNA and protein in stellate ganglia of rats and mice, although in much smaller amounts compared with adrenal medulla. PNMT gene expression and protein levels were also increased after repeated stress exposure in stellate ganglia of rats and wild-type mice. Similarly to adrenal medulla, the immobilization-induced increase was probably regulated by glucocorticoids, as determined indirectly using corticotropin-releasing hormone knockout mice, where immobilization-induced increase of PNMT mRNA was suppressed. Thus, glucocorticoids might play an important role in regulation of PNMT gene expression in stellate ganglia under stress conditions. [source] The characterization of fluidization behavior using a novel multichamber microscale fluid bedJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 3 2004Eetu Räsänen Abstract In the preformulation stage, there is a special need to determine the process behavior of materials with smaller amounts of samples. The purpose of this study was to assemble a novel automated multichamber microscale fluid bed module with a process air control unit for the characterization of fluidization behavior in variable conditions. The results were evaluated on the basis of two common computational methods, the minimum fluidization velocity, and the Geldart classification. The materials studied were different particle sizes of glass beads, microcrystalline cellulose, and silicified microcrystalline cellulose. During processing, the different characteristic fluidization phases (e.g., plugging, bubbling, slugging, and turbulent fluidization) of the materials were observed by the pressure difference over the bed. When the moisture content of the process air was increased, the amount of free charge carriers increased and the fine glass beads fluidized on the limited range of velocity. The silicification was demonstrated to improve the fluidization behavior with two different particle sizes of cellulose powders. Due to the interparticle (e.g., electrostatic) forces of the fine solids, the utilization of the computational predictions was restricted. The presented setup is a novel approach for studying process behavior with only a few grams of materials. © 2004 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 93: 780,791, 2004 [source] Ring-opening reactions of 5-(aryl)thianthrenium bromides with aryl thiolatesJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 3 2002Ding-Quan Qian Abstract A series of 5-(aryl)thianthrenium bromides (6a,e) with aryl (Ar) groups phenyl (a), p -tolyl (b), p -anisyl (c), p -chlorophenyl (d) and p -bromophenyl (e) was prepared by reaction of thianthrene 5-oxide with the appropriate Grignard reagent ArMgBr. Reactions of 6a,e with aryl thiolates (Ar,SNa, Ar,,=,phenyl, p -tolyl and p -chlorophenyl, 7a,c) were carried out in MeCN at room temperature. Products from 6a,c were a small amount of arene [benzene (8a) and toluene (8b)], and substantial amounts of ArSAr, (9), thianthrene (Th) and a trisulfide, namely a 2-(ArS)-2,-(Ar,S)-diphenyl sulfide (10). Products from reactions of 6d,e were smaller amounts of 9 and 10 but substantial amounts of 1,4-di(Ar,S)benzene (11) and a tetrasulfide (12a,c). The reactions that lead to products 9,12 are attributed to ligand coupling (LC) pathways in sulfuranes formed by attack of Ar,S, at the sulfonium S atom of 6. In the formation of 11 and 12 the halogen atom (Cl, Br) is first displaced from 6d,e by Ar,S,, giving a new thianthrenium ion (14) from which sulfurane formation (15) follows. Products 10 and 12 result from opening of the thianthrenium ring of sulfuranes 13 and 15 through LC. Products were assayed with a combination of GC and isolation with TLC, and were identified with a combination of GC (authentic compounds), x-ray crystallography (10a), elemental analyses and high-resolution mass spectrometry. The reactions of 6 are compared with earlier reactions of 5-(alkoxy)-and 5-(alkyl)thianthrenium salts (1 and 2). Copyright © 2002 John Wiley & Sons, Ltd. [source] The role of hepatic peroxisome proliferator-activated receptors (PPARs) in health and diseaseLIVER INTERNATIONAL, Issue 3 2000Lynn Everett Abstract: The liver has long been known to respond to exposure to certain chemicals with hyperplasia and proliferation of the peroxisomal compartment. This response is now known to be mediated by specific receptors. The peroxisome proliferator-activated receptors (PPARs) were cloned 10 years ago, and in that interval, have been found to serve as receptors for a number of endogenous lipid compounds, in addition to the peroxisome proliferators that originally led to their study. Three receptors, designated the ,, ,, and , receptors, have been found in mammals. PPAR, is the most abundant form found in the liver, with smaller amounts of the , and , forms also expressed there. Kupffer cells, like other macrophages, appear to express the , and , isoforms. Hepatic stellate cells are reported to express the , isoform. PPAR, knock-out mice fail to undergo peroxisome proliferation when challenged with the proliferators. Moreover, they have severe derangements of lipid metabolism, particularly during fasting, indicating that normal function of the alpha receptors is needed for lipid homeostasis. This in turn suggests that inadequate PPAR-mediated responses may contribute to abnormal fatty acid metabolism in alcoholic and non-alcoholic steatohepatitis. Recent information suggests that PPAR, receptors may be important in control of the activation state of the stellate cells, and their repression or inactivation may predispose to hepatic fibrosis. The first approved drug that specifically activates PPAR,, troglitazone, has rarely been found to cause serious liver injury. Although this is likely to represent an idiosyncratic reaction, the medical community will need to be alert to the possibility that activation or blockade of these receptors may cause hepatic dysfunction. [source] Advancement of renewables in Bangladesh and Thailand: Policy intervention and institutional settingsNATURAL RESOURCES FORUM, Issue 3 2006Sk Noim Uddin Abstract This article reviews and analyses the advancement of renewable sources of energy in Bangladesh and Thailand in terms of policy intervention and institutional settings. Since renewable forms of energy emit far smaller amounts of greenhouse gas compared with fossil fuels, their use should mitigate climate change impacts while contributing to the provision of energy services. The article turns first to a review of energy,environment trends and the potential for renewables in these two nations. It then discusses strategies for the advancement of renewables. It is argued that further significant efforts can be made towards the advancement of renewables in Bangladesh and Thailand. These two nations could also learn from the experience in industrialized nations and other developing nations with regard to requisite policy instruments and processes. A number of barriers remain to the advancement of renewables, especially in terms of policy arrangements, institutional settings, financing mechanisms and technologies. Resources, cooperation and learning are required in order to overcome such barriers and to foster the development of necessary policy measures. Implementation of the clean development mechanism (CDM) under the Kyoto Protocol, and replication and adaptation of effective strategies from other settings are possible avenues for this. [source] Effects of supplementary pollination on cropping success and fruit quality in pistachioPLANT BREEDING, Issue 5 2002Y. Vaknin Abstract The effects of pollen supplementation in pistachio orchards using an electrostatic pollination device were investigated in a 3-year study (1996-98) in San Joaquin Valley, California, USA. Both yield and fruit quality (per cent split fruit) were tested in several experiments. Applying smaller amounts of pollen (1.5 g per tree in early application only in 1996 or 0.5 g in two applications in 1997) resulted in higher yields than with open pollination or supplementary pollination using larger amounts of pollen (1.5 g per tree in four applications in 1996 or 1.0 g in two applications in 1997). Applying 1.0 g pollen in two applications in 1998 resulted in decreased yields compared with open pollination or non-electrostatic pollination. Pollen germinability on the stigma was greatest for open pollination suggesting that overloading the stigmas with pollen in supplementary pollination may not only reduce yield but also increase competition between pollen grains. The per cent split fruit significantly increased only once in 1996. When pollination is a limiting factor, electrostatic pollination of pistachio can increase yield and may even increase fruit quality. However, when pollination is not a limiting factor, electrostatic pollination may even reduce yield. [source]
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