bluuebunny/crossref_metadata_2025_split huggingface dataset:
Iron(III)‐Complexes Engaged in the Biochemical Processes in Seawater. II. Voltammetry of Fe(III)‐Malate Complexes in Model Aqueous Solution
Authors: Vukosav Petra , Tomišić Vladislav , Mlakar Marina 
Published: August 2010

AbstractCharacteristics of iron(III) complexes with malic acid in 0.55 mol L−1 NaCl were investigated by voltammetric techniques. Three iron(III)‐malate redox processes were detected in the pH range from 4.5 to 11: first one at −0.11 V, second at −0.35 V and third at −0.60 V. First process was reversible, so stability constants of iron(III) and iron(II) complexes were calculated: log K1(FeIII(mal))=12.66±0.33, log β2(FeIII(mal)2)=15.21±0.25, log K1(FeII(mal))=2.25±0.36, and log β2(FeII(mal)2)=3.18±0.32. In the case of second and third reduction process, conditional cumulative stability constants of the involved complexes were determined using the competition method: log β(Fe(mal)2(OH)x)=15.28±0.10 and log β(Fe(mal)2(OH)y)=27.20±0.09.
Measurement of Stevioside by Square‐Wave Polarography
Authors: Komorsky‐Lovrić Šebojka , Novak Ivana , Novak Bruno 
Published: August 2010

AbstractSteviol glycosides are electroactive compounds and can be detected by mercury electrode. The maxima of square‐wave polarograms of steviol and stevioside appear at −1.3 V vs. Ag/AgCl in 1 M NaCl at approximately pH 11. The responses are quasireversible and probably caused by electroreduction of carboxyl, or ester groups, respectively. The net peak current is linearly proportional to steviol concentration between 1×10−6 mol/L and 3.5×10−5 mol/L. This calibration plot can be used for the determination of the concentration of stevioside in extracts of stevia (Stevia rebaudiana Bertoni) leaves. The proposed method is applicable for routine analysis of stevioside in commercial products.
Label‐Free Electrochemical Biosensor of Mercury Ions Based on DNA Strand Displacement by Thymine–Hg(II)–Thymine Complex
Authors: Liu Xueping , Sun Chenhu , Wu Huiwang , Zhang Yifang , Jiang Jianhui , Shen Guoli , Yu Ruqin 
Published: August 2010

AbstractA novel electrochemical biosensor for the determination of mercury ions in aqueous solution has been reported. The sensing substrate with a layer of gold nanoparticles on the gold electrode surface was formed through 1,6‐hexanedithiol connection, which could enhance the surface loading of the capture DNA probe and improve the electron transfer performance. Another DNA probe used as mercury ion specific binding (MSB) probe hybridized with the capture probe. In the presence of mercury ions, the easy formation of thymine–Hg2+–thymine structure destabilized the hybrid complex and caused MSB probe released from the interface. As a result, the amount of electroactive indicator Methylene blue (MB) adsorbed by the remained DNA on the electrode surface decreased, which weakened the current signal. Therefore, the change of the redox current could reflect the concentration of the analyte. A linear relationship between the current signal and the logarithm of the target concentration up to 500 nM was obtained, with a detection limit of 0.32 nM. The fabricated sensor is shown to exhibit high sensitivity, desirable selectivity and excellent application in real sample analysis.
Determination of Trace Tl(I) by Anodic Stripping Voltammetry on Novel Disposable Microfabricated Bismuth‐Film Sensors
Authors: Kokkinos Christos , Raptis Ioannis , Economou Anastasios , Speliotis Thanassis 
Published: August 2010

AbstractThis work reports the trace determination of Tl(I) by square‐wave anodic stripping voltammetry (SWASV) on novel microsensors equipped with a bismuth‐film electrode (BiFE). The sensors were fabricated by a multistep microfabrication approach combining sputtering (to deposit the electrode materialm, bismuth‐ and the insulator SiO2, on the surface of a silicon wafer) and photolithography (to define the geometry of the sensor). The effect of the preconcentration time, the preconcentration potential and the SW stripping parameters were investigated. Using the selected conditions, the 3σ limit of detection was 0.6 µg L−1 of Tl(I) at a preconcentration time of 240 s and the percent relative standard deviation was 4.3 % at the 10 µg L−1 level (n=8). In order to eliminate the interference caused by Pb(II) and Cd(II), EDTA was added in the sample solution The method was successfully applied to the determination of Tl(I) in a certified lake water sample. These new sensors exhibit excellent mechanical stability and offer wide scope as mercury‐free disposable sensors for trace metal analysis.
A Voltammetric Sensor Based on Modified Multiwall Carbon Nanotubes for Cysteamine Determination in the Presence of Tryptophan Usingp‐Aminophenol as a Mediator
Authors: Ensafi Ali A. , Karimi‐Maleh Hassan 
Published: August 2010

AbstractDetermination of cysteamine and tryptophan is described by electrochemical methods usingp‐aminophenol‐multiwall carbon nanotubes paste electrode. Cysteamine and tryptophan in mixture can each be measured independently from each other with a potential difference of 600 mV. The results showed that the electrocatalytic currents increased linearly with cysteamine and tryptophan concentrations over the ranges 0.5–300 µmol L−1and 10.0–650 µmol L−1, respectively. The detection limits for cysteamine and tryptophan are found to be 0.14 and 5.9 µmol L−1, respectively. The proposed method is successfully employed for the determination of cysteamine in both capsule and urine samples.
Nucleation and Growth Mechanism of Electropolymerization of Methylene Blue: The Effect of Preparation Potential on Poly(methylene blue) Structure
Authors: Kaplan İbrahim Hakkı , Dağcı Kader , Alanyalıoğlu Murat 
Published: August 2010

AbstractNucleation and growth mechanism of electropolymerization of methylene blue (MB) in a basic medium and the effect of preparation potential on poly(MB) film structure were investigated by using cyclic voltammetry, potentiostatic current‐time transient, scanning tunneling microscopy (STM), atomic force microscopy (AFM), and UV‐vis. absorption spectroscopy techniques. Electropolymerization of MB has been achieved by potentiodynamic (cyclic voltammetry) and potentiostatic (constant potential) techniques. The potentiostatic current‐time transients fitted with a theoretical model and morphological studies indicate that nucleation and growth mechanism of poly(MB) starts with a progressive layer‐by‐layer nucleation and growth besides random adsorption. Nucleation and growth of poly(MB) follows a process between progressive layer‐by‐layer and 3‐D instantaneous mechanism resulting in highly‐oriented poly(MB) nanofibers with increasing poly(MB) film thickness. Cyclic voltammetry and morphological studies exhibit that poly(MB) film structure changes depending on the preparation potential. Poly(MB) films prepared at the potential values of 900 and 950 mV show a well‐ordered, smooth surface but at the potential values higher than 1000 mV, rough polymer surface arises as overoxidation takes place. UV‐vis. absorption spectra of poly(MB) film and MB monomer show three peaks. The peak at 410 nm for poly(MB) shows 100 nm blue shift when compared to the MB monomer and is attributed to poly(MB) formation on the electrode.
A contribution to the development of an erosivity index adapted to the prediction of erosion in Belgium
Authors: Sinzot A. , Bollinne A. , Laurant A. , Erpicum M. , Pissart A. 
Published: August 2010

AbstractIn the Universal Soil Loss Equation, only rains in excess of, or equal to, 12‐7 mm are taken into account and their intensity is represented by the maximum intensity reached over a 30 minute period. In Belgium, erosion recorded on experimental plots displays closest correlation to rainfall if a value superior or equal to 8 mm and a maximum intensity over 15 minutes are considered. Moreover the highest correlation is obtained by using the rainfall energy calculation formula put forward by Bollinne et al. (1984). The differences between the correlation coefficients are however not statistically significant and consequently the results point only to general trends. The suggested modification of the USLE is probably the result of the different nature of the precipitation in Belgium as compared with the U.S.A.
Pedogenic indicators of subsurface flow on Judean Desert Hillslopes
Authors: Lavee H. , Wieder M. , Pariente S. 
Published: August 2010

AbstractPedogenic features considered to be produced by subsurface flow were observed on the hillslopes of a zero‐order basin in the Judean desert where the mean annual rainfall is 230 mm. The basin, some 5000m2in area, is composed of soft chalk covered by soil material, with slope gradients ranging from 30‐60 per cent.A comparison of carbonate, gypsum, and soluble salts distribution within the soil, and also their characteristics in this study area, to the same variables in other arid environments, allows one to determine and analyse pedogenic indicators of subsurface flow. In particular gypsic crusts, which exhibit specific characteristics not observed in other areas where pedogenic features are controlled by vertical limited leaching, highlight the existence of lateral subsurface flow.The spatial distribution of these pedogenic indicators within the basin and in the soil was analysed in terms of soil water regime, soil thickness, and the permeability of the soil and bedrock.
Towards the regionalization of hydraulic and plant‐soil parameters for modelling soil moisture conditions of a catchment
Authors: Van Berg Jan A. Den 
Published: August 2010

AbstractComputational simulation of the moisture regime of the soil is a useful help in studying land potential, ecology, and land degradation processes such as soil erosion and mass movement. The utility of modelling soil moisture depends on the validity of the model structure and of the model parameters. Moreover, except for differences in relief and for variation in rainfall and net radiation, such a model will show spatial variability only if the variability of the ecological properties of the soil and the vegetation canopy can be input.Eight experimental sites on erodible loamy to silty soils in the Ardèche Basin, France, were investigated, to ascertain how the information required for modelling soil moisture can be obtained.Three terms of the soil moisture budget were measured or determined for compiling the model structure: rainfall, soil moisture content (or capillary pressure head), and actual evapotranspiration. The latter was calculated with the Bowen ratio method from the energy balance measured at three sites. These data were also to calculate the canopy resistance in the evaporation formula based on transport resistances.To study how to regionalize the hydraulic parameters, the characteristic of unsaturated conductivity and soil moisture diffusivity as a function of moisture content or capillary pressure head were determined by the hot air method for intermediate moisture contents and with the crust method on soil columns in situ for high moisture contents.Estimation of the diffusivity from soil texture appeared to be less successful for fine‐textured soils. Macropores apparently crucially influenced the capacity of ponding infiltration and the frequency of overland flow.
The use of digital elevation models for flood hazard mapping
Authors: Leenaers H. , Okx J. P. 
Published: August 2010

AbstractGeomorphological processes that are active in floodplain areas are related to terrain elevation. The rate of sedimentation, as well as the texture and the quality of the deposited sediments, depend on the frequency of flooding and the sedimentary conditions during flood events. In addition to geomorphological and soil maps, digital elevation models may provide a sound base for quantitative studies of these processes: flood hazard and, in the case that historical elevation data are available, sedimentation and erosion rates may be derived from the digital representation of relief over space.This paper discusses the interpolation techniques and the test procedures that were used to compute a digital elevation model of a part of the floodplain area of the River Geul (the Netherlands). It was found that the fitting of mathematical splines outperforms local averaging and inverse distance weighting for estimating floodplain elevation.By means of the Digital Elevation Model and a long profile of the river, a flood hazard map was constructed. Photographs of a flood event were used for validation. Analysis of variance revealed that 57‐65 per cent of the variance in a set of data on flood‐related topsoil metal content can be accounted for by the flood hazard map.
Freshwater community responses to mixtures of agricultural pesticides: Effects of atrazine and bifenthrin
Authors: Hoagland Kyle D. , Drenner Ray W. , Smith J. Durward , Cross David R. 
Published: August 2010

AbstractThe individual and combined effects of atrazine and bifenthrin on lake communities were investigated in a two-phased mesocosm study involving eighteen 5,500-L tanks containing natural plankton assemblages and bluegill. The factorial-designed experiment included three levels of bifenthrin (0, 39, and 287 ng L−1 in phase 1 and 0, 125 and 3,150 ng L−1 in phase two) cross-classified with three levels of atrazine (0, 15, and 153 μg L−1 in phase 1 and 0, 385, and 2, 167 μg L−1 in phase 2), with duplicate replication. In phase 1, atrazine significantly reduced chlorophyll concentrations and turbidity (day 7) but had no significant impact on primary productivity or algal cell densities. Bifenthrin significantly reduced Bosmina (days 7 and 14), cyclopoid copepodids (days 7 and 14), and copepod nauplii (day 14); however, bifenthrin increased rotifers at day 7. Bifenthrin also increased colonial green algae (day 7) and decreased turbidity (days 7 and 14). Only one fish mortality occurred during phase 1 of the study. In phase 2, atrazine resulted in significant reductions in primary productivity, chlorophyll, green algal colonies, Bosmina, and rotifers on day 7. Bifenthrin had a negative impact on Bosmina, copepod nauplii, rotifers, primary productivity, chlorophyll, and green algal colonies. A 33% bluegill mortality was observed in tanks with an average maximum concentration of 3,150 ng L−1 bifenthrin. The observed interaction effects indicated that when either compound was introduced at ecologically realistic levels, its effects were essentially masked if the other toxicant was present at high concentrations, and that the two pesticides did not act synergistically.
Submediterranean Weeds and Their Local Distribution Shown in a Sector of the Thuringian Trias‐Landscape
Authors: Ladwig E. 
Published: August 2010

Der untersuchte Gebietsausschnitt vom Westrande des Thüringer Beckens und seiner Randplatten ist eine mit Löß überformte Triaslandschaft, vorwiegend mit Keupertonen und Muschelkalk. Niederschläge und Temperatur folgen i. W. den geographischen Höhenlagen (ca. 210 m—480 m NN), nur die Werrasteilhänge zeigen mesoklimatische, auch floristisch dokumentierte Besonderheiten. Der Löß (östlich des Hainichs) tendiert wegen der rel. hohen Niederschläge (um 600 mm) zur Oberflächenverdichtung und Entbasung. In den meisten Verbreitungskarten sind daher die beiden Lößrücken positiv oder negativ gut herausgehoben. Nach der Häufigkeit und Verteilung im UG lassen sich die submediterranen Segetalpflanzen in 8 Gruppen zusammenfassen. Die wesentlichsten sind:Sehr häufige und fast gleichmäßig über das UG verbreitete Arten (z. B.: Sinapis arvensis, Euphorbia exigua)Weniger häufige, doch etwa gleichmäßig verteilte Arten (z. B.: Ranunculus arvensis, Papaver argemone)Arten, deutlich den Lößboden bevorzugend (schwach säureliebend bzw. Anzeiger für Oberflächenverdichtung: z. B.: Raphanus raphanistrum, Scleranthus annuus)Kalkliebende Unkräuter (z. B.: Caucalis platycarpos, Scandix pecten‐veneris, Euphorbia platyphyllos)Ähnlich kalkliebend, aber mit stark ruderaler Ausprägung (Reseda lutea).In der kleinräumigen Verbreitung spielen die ökologischen Faktoren eine deutlich größere Rolle als die pflanzengeographischen Beziehungen.Die Intensivierung des Ackerbaues und die neuen Methoden regelmäßiger und allgemeiner Unkrautbekämpfung haben die Lebensbedingungen grundlegend verändert, und darum wird sich das Spektrum der Unkräuter innerhalb relativ kurzer Zeit durch das Verschwinden vieler Arten nach den widerstandfähigsten hin verschieben.
Wirtschaftsgrünland, Röhrichte und Seggenriede der Ryckniederung (Nordost‐Mecklenburg)
Authors: Krisch Haubold 
Published: August 2010

AbstractDie vorliegende Arbeit ist eine pflanzensoziologische Untersuchung des Grünlandes der im Flachland der DDR gelegenen Ryckniederung. Nach einer Einführung in das Untersuchungsgebiet werden auf der Grundlage von 357 soziologischen Aufnahmen 35 Pflanzengesellschaften (meist im Range von Assoziationen) geschildert, die im folgenden Inhaltsverzeichnis namentlich aufgeführt sind. Mit Ausnahme des Phragmitetum, des Equisetetum, der Caltha palustris‐Equisetum fluviatile‐Gesellschaft, der Menyanthes trifoliata‐Bestände und der Carex paniculata Gesellschaften sowie einigen der Glyceria maxima‐ und der Carex elata‐Gesellschaften handelt es sich immer um gemähtes oder beweidetes Grünland.Eine Bearbeitung der Vegetation der an das Untersuchungsgebiet grenzenden Boddenküste einschließlich der Salzweiden wurde vom selben Autor in „Feddes Repertorium”︁ 85 (1–2) vorgelegt.
Die GattungenThevetiaL.,CerberaL. undCascabelaRafin. (Apocynaceae)
Authors: Lippold H. 
Published: August 2010

AbstractDie GattungThevetiaL. (nom. cons.) wird als monotypische Gattung mit der ArtTh. ahouai(L.) DC. aufgefaßt. Die GattungCerberaL. wird beschränkt auf Arten aus dem asiatischen Raum. NebenC. manghasL. als Typus‐Art werdenC. batjanicaTEJSM. et BINN.,C. dilatataMARKG.,C. floribundaK. SCHUM.,C. fruticosaROXB.,C. micrantha(KANCHIRU) PICHON,C. obtusifloraHEURCK,C. oppositifoliaLAM. undC. parvifloraLAM., zugeordnet.CascabelaRAFIN. ist der älteste Name für die Gattung der Verwandten von “Cerbera thevetiaL.” aus dem amerikanischen Raum. Hierzu gehören:Cascabela thevetia(L.) LIPPOLD als Typus‐Art undC. alliadora(R. et S.) LIPPOLD,C. bicornuta(MUELL.‐ARG.) LIPPOLDC. gaumeri(HEMSL.) LIPPOLD,C. ovata(CAV.) LIPPOLD,C. plumeriaefoliaBENTH. LIPPOLD undC. thevetioides(HBK.) LIPPOLD.
Pattern separation in the dentate gyrus: A role for the CA3 backprojection
Authors: Myers Catherine E. , Scharfman Helen E. 
Published: August 2010

AbstractMany theories of hippocampal function assume that area CA3 of hippocampus is capable of performing rapid pattern storage, as well as pattern completion when a partial version of a familiar pattern is presented, and that the dentate gyrus (DG) is a preprocessor that performs pattern separation, facilitating storage and recall in CA3. The latter assumption derives partly from the anatomical and physiological properties of DG. However, the major output of DG is from a large number of DG granule cells to a smaller number of CA3 pyramidal cells, which potentially negates the pattern separation performed in the DG. Here, we consider a simple CA3 network model, and consider how it might interact with a previously developed computational model of the DG. The resulting “standard” DG‐CA3 model performs pattern storage and completion well, given a small set of sparse, randomly derived patterns representing entorhinal input to the DG and CA3. However, under many circumstances, the pattern separation achieved in the DG is not as robust in CA3, resulting in a low storage capacity for CA3, compared to previous mathematical estimates of the storage capacity for an autoassociative network of this size. We also examine an often‐overlooked aspect of hippocampal anatomy that might increase functionality in the combined DG‐CA3 model. Specifically, axon collaterals of CA3 pyramidal cells project “back” to the DG (“backprojections”), exerting inhibitory effects on granule cells that could potentially ensure that different subpopulations of granule cells are recruited to respond to similar patterns. In the model, addition of such backprojections improves both pattern separation and storage capacity. We also show that the DG‐CA3 model with backprojections provides a better fit to empirical data than a model without backprojections. Therefore, we hypothesize that CA3 backprojections might play an important role in hippocampal function. © 2010 Wiley Periodicals, Inc.
TREATMENTS AND ECONOMIC ASPECTS OF GROWING RICE AND WHEAT CROPS DURING RECLAMATION OF TILE DRAINED SALINE‐SODIC SOILS USING BRACKISH WATERS
Authors: Ghafoor A. , Murtaza G. , Maann A.A. , Qadir M. , Ahmad B. 
Published: August 2010

ABSTRACTWe carried out three field experiments on salt‐affected soils having tile drainage in place, which differed in ambient levels of electrical conductivity and sodium adsorption ratio. The 3‐year cropping sequence consisted of a rice–wheat rotation. These crops were irrigated with waters having different levels of salinity (EC 2.7–4.5 dS m−1), and sodicity (SAR 8.0–28.8 and residual sodium carbonate 1.3–14.9 mmolc L−1). The treatments on all the sites were the same and consisted of: (1) Irrigation with saline/sodic water without amendment (control); (2) Sesbania green manure each year (SGME); (3) Soil‐applied gypsum equivalent to gypsum requirement of water (GWR), and (4) Soil‐applied gypsum as in treatment 3 plus sesbania green manure each year (G + SGME). We found a decreasing trend in soil salinity and sodicity and favourable levels of infiltration rate and bulk density over pre‐experiment levels. In terms of overall treatment effectiveness in causing a decrease in soil salinity and sodicity, G + SGMEcaused the greatest decrease. Based on our multi‐location and long‐term study, we propose a combination of gypsum and sesbania green manuring each year. This is an important resource conservation intervention that helps to mitigate the ill effects of salts and improves crop yields on salt‐affected soils where low‐quality water is used for irrigation. Copyright © 2010 John Wiley & Sons, Ltd.
Osteoblasts are a major source of inflammatory cytokines in the tumor microenvironment of bone metastatic breast cancer
Authors: Bussard Karen M. , Venzon David J. , Mastro Andrea M. 
Published: August 2010

AbstractMetastatic breast cancer cells co‐opt the cells of the bone to increase their production of inflammatory cytokines. Here, we sought to identify key cytokines expressed by osteoblasts in vitro and in vivo in the presence of MDA‐MB‐231 metastatic breast cancer cells, including a bone‐seeking variant. We hypothesized that osteoblast‐derived cytokines increase in the presence of metastatic breast cancer cell conditioned medium (CM), act as chemoattractants for cancer cells, and enhance osteoclast formation. We detected increases in the concentrations of osteoblast‐derived IL‐6, MCP‐1, VEGF, MIP‐2, and KC in vitro in culture supernatants from MC3T3‐E1 cells in the presence of metastatic breast cancer cell CM and from cancer‐bearing femurs ex vivo. A comparison of cancer cell‐ and osteoblast‐derived cytokines revealed that while breast cancer cells expressed the same or equivalent cytokines as the osteoblasts, the breast cancer cells only produced picogram quantities of MCP‐1; osteoblasts expressed nanogram amounts. Bone‐derived MCP‐1 increased in the proximal metaphysis, an area where breast cancer cells preferentially trafficked following intracardiac inoculation in athymic mice. An MDA‐MB‐231 bone‐seeking variant was not different from parental lines. Osteoblast CM was a potent chemoattractant for metastatic breast cancer cells. Furthermore, culture supernatants of osteoblasts treated with breast cancer cell CM enhanced osteoclast formation. These findings suggest that bone metastatic breast cancer cells utilize osteoblast‐derived cytokines to facilitate breast cancer cell colonization and survival upon arrival in the bone microenvironment. J. Cell. Biochem. 111: 1138–1148, 2010. © 2010 Wiley‐Liss, Inc.