bluuebunny/crossref_metadata_2025 huggingface dataset:
Are runoff processes ecologically or topographically driven in the (sub) humid Ethiopian highlands? The case of the Maybar watershed
Authors: Bayabil Haimanote K. , Tilahun Seifu A. , Collick Amy S. , Yitaferu Birru , Steenhuis Tammo S.
Published: October 2010

Understanding the basic runoff processes in the Ethiopian highlands is vital for effective management and utilization of water resources and soil conservation planning. An important question for judging the effectiveness of conservation practices is whether runoff is affected by ecology (mainly type of crop) or topography (landscape). A study was conducted in the 113 ha watershed of Maybar, located in the highlands. This watershed has long‐term records of rainfall and discharge. To study runoff processes, piezometers were installed in eight transects up and down the slope. In addition, infiltration rates (measured earlier) were compared with rainfall intensities. The results show that the amount of runoff at the test plots was greater for cropland located on mild to intermediate slopes than for grasslands and woodlands on the steeper slopes. Water tables were closer to the surface on cropland for the mild to intermediate slopes than on grasslands and in woodlands for the steeper slopes. Thus, although water table depths and plot runoff were inconclusive on the type of runoff mechanisms, infiltration rates that were generally in excess of the rainfall rates imply that any ecological effect on the amount of surface runoff is small. This is because water infiltration is independent of crop type. Only in cases where the soil was saturated did runoff occur. Piezometer readings show that saturation occurs at the foot of the steep slopes and, therefore, it demonstrates that topographic processes are dominant. Ecology becomes important when infiltration rates are in the same order as the rainfall intensities. Copyright © 2010 John Wiley & Sons, Ltd.
Binding of Catechols to Iron(III)–Octaethylporphyrin: An Experimental and DFT Investigation
Authors: Chaudhary Arvind , Patra Ranjan , Rath Sankar Prasad
Published: October 2010

The synthesis, X‐ray structure, and properties of high‐spin, five‐coordinate catecholate complexes of (octaethylporphyrinato)iron(III), FeIII(OEP)(L) (L: catecholate monoanion), are reported here for the first time. In these complexes, catechol binds in an η1‐fashion as an axial ligand, which is supported by DFT calculations. The Fe–O–C angles of FeIII(OEP)(Hcat), FeIII(OEP)(4‐tBu‐Hcat), FeIII(OEP)(4‐NO2‐Hcat), and FeIII(OEP)(sal) are 119.5, 125.1, 122.2, and 124.3°, respectively. FeIII(OEP)(Hcat) has the smallest Fe–O–C angle in addition to the smallest dihedral angle of 26.2° between the planes of the porphyrin and axial catechol ligand among all phenolate complexes of iron(III)–porphyrins. In comparison to those of FeIII(OEP)(OPh) and FeIII(OEP)(4‐tBu‐Hcat), the Fe–O bond in FeIII(OEP)(Hcat) is elongated by 0.064 and 0.038 Å, respectively. This is due to the H‐bonding interactions in FeIII(OEP)(Hcat) and not caused by steric hindrance. In the 1H NMR spectra of the complexes, the signals of the ortho‐ and para‐protons of catechol are shifted upfield, whereas those of the meta‐protons are shifted downfield. The alternating shift pattern observed is due to negative and positive spin densities on the catechol carbon atoms and is indicative of π‐spin delocalization on the catecholato ligand. Electrochemical data reveal that the complexes undergo three one‐electron oxidations and a single one‐electron reduction. Based on spectroelectrochemical and DFT studies, the first oxidation is assigned to a catechol‐to‐semiquinone transformation and the second and third oxidations are found to be porphyrin‐ring‐centered.
Woody biomass and mill waste utilization opportunities in Alabama: Transportation cost minimization, optimum facility location, economic feasibility, and impact
Authors: Aksoy Burak , Cullinan Harry , Webster David , Gue Kevin , Sukumaran Sujith , Eden Mario , Sammons Norman
Published: October 2010

Four biorefinery technologies were studied for feedstock allocation, optimum facility location, economic feasibility, and their economic impacts on Alabama. The studied technologies are: (1) circulated fluidized bed gasification of woody biomass for Fischer‐Tropsch (F‐T) fuels and power production; (2) simultaneous saccharification and fermentation (SSF) of paper sludge for ethanol production; (3) direct spouted bed (DSB) gasification with air and steam of woody biomass for power; and (4) direct combustion of woody biomass for power production. The optimum biorefinery locations for all four processes were southwestern Alabama. The average transportation distance for woody biomass was about 32 miles (51.5 km) to the biorefinery plants; however, longer transportation distances were required for paper sludge where the feedstock is provided by the pulp and paper plants in the region. The SSF process along with the DSB gasification process were the only economically feasible biorefinery technologies with an over 80 and 22.5% internal rate of return, respectively. Economic impacts of all the studied biorefinery technologies were comparable to each other. © 2010 American Institute of Chemical Engineers Environ Prog, 2010.
Equilibrium and kinetic studies of the adsorption of basic dye from aqueous solutions by zeolite synthesized from bagasse fly ash
Authors: Shah Bhavna A. , Patel Harendra D. , Shah Ajay V.
Published: October 2010

This study is envisaged for modification of sugar industry waste bagasse fly ash (BFA) into a beneficial sorbent zeolite (ZFA) having improved morphology for the effective removal of basic dye methylene blue (MB) from aqueous solution. BFA was efficiently transformed to ZFA by alkaline hydrothermal treatment. Both the virgin and treated BFA were characterized using various techniques to obtain its physical and chemical constituents. The major change in the morphology of BFA and ZFA was examined by X‐ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy. Modified adsorbent ZFA showed surface with deeper pore, indicating vanishing crystalline glass phase of BFA. The equilibrium and kinetic studies are carried out with the synthetic solutions of MB. It was found that the solute removal is favored at a lower solute concentration, increased agitation time, increased dose of adsorbent, and higher temperature. The adsorption capacities of BFA and ZFA were found to be 71% and 45%, respectively, for removal of MB at optimized conditions. Langmuir, Freundlich, and Dubinin‐Radushkevich isotherm models were adopted to describe the adsorption isotherms. Adsorption isotherms of MB dye could be best modeled by Dubinin‐Radushkevich isotherm for ZFA and Langmuir isotherm for BFA. The results clearly showed that the removal capacity of ZFA was seen to be higher than that of BFA. © 2010 American Institute of Chemical Engineers Environ Prog, 2010.
Expressed emotion measure adaptation into a foreign language
Authors: Rein Z. , Duclos J. , Perdereau F. , Curt F. , Apfel Alexandre , Wallier J , Verdier A. , Fermanian J. , Falissard B. , Zaden S. , Godart N. T.
Published: October 2010

Expressed emotion (EE) measures have been created in English; adaptation into a foreign language is difficult. The aim of this study was to adapt the five minutes speech sample (FMSS), with a designed procedure ensuring optimum quality of the adaptation, and thus better trans‐cultural validity. A strategy for improving inter‐rater agreement comprised three phases: (1) phase of initial ratings (70 French samples), (2) experimental phase in two steps: ratings of 40 other samples in French, followed by analysis of differences between the French‐language ratings and English‐language ratings and (3) final rating phase of the initial 70 samples. For each phase, the κ coefficients measuring inter‐rater agreement were calculated and compared using a bootstrap procedure. The improvements between these scorings were significant at p < 0.05 (phase 2 initial versus phase 2 final and phases 1 versus 3). The French inter‐rater agreement significantly improved after this procedure. Copyright © 2010 John Wiley & Sons, Ltd and Eating Disorders Association.
Interpreting luminescence data from a portable OSL reader: three case studies in fluvial settings
Authors: Muñoz‐Salinas Esperanza , Bishop Paul , Sanderson David CW , Zamorano Jose‐Juan
Published: October 2010

Optically stimulated luminescence (OSL) is a technique that has been applied from the mid‐1980s, mainly for sediment dating. The OSL technique is based on sample stimulation by light to determine the luminescence signal that is stored in the crystal lattices of sediment grains after deposition, burial by later sediment and subsequent exposure to ionizing radiation from radioactive elements in the surrounding sediment. In such sediment dating, two parameters are required: the equivalent dose (i.e. the luminescence signal stored in the grains), and the dose rate (i.e. the ionizing energy from α, β and γ radiation emitted by naturally occurring radioisotopes in the deposit, plus the effects of cosmic radiation). In this research, the OSL technique is not used for dating. The study goal is to analyse only the luminescence signals (the total photon counts) in polymineral samples obtained after light stimulation in the blue (BLSL) and infrared (IRSL) wavelengths using a portable OSL reader designed and built at the Scottish Universities Environmental Research Centre (SUERC). Three fluvial case studies – from Cambodia, Australia and Mexico – are used to illustrate the geomorphological interpretations possible with the portable OSL reader data from sediments resulting from a range of different depositional processes. The case studies show that aspects of sediment's transport and depositional processes can be inferred from the portable OSL reader data, providing valuable insights into geomorphological history. Copyright © 2010 John Wiley & Sons, Ltd.
Atypically low spontaneous sister chromatid exchange formation in uveal melanoma
Authors: Hoh Leslie , Gravells Polly , Canovas David , Ul‐Hassan Aliya , Rennie Ian G. , Bryant Helen , Sisley Karen
Published: October 2010

Uveal melanoma (UM) is the most common primary intraocular cancer of adults and is characterized by several well‐established chromosomal changes. More recently, a specific mutation of guanine nucleotide binding protein Gq alpha subunit (GNAQ) has also been identified in a proportion of UM. Although some of these alterations have been suggested to be early changes, the genetic alterations responsible for the development of UM have yet to be clearly determined. Cancers are characterized by increased genetic instability, and analysis of established cancer cell lines and blood from cancer patients has universally been associated with an increased level of sister chromatid exchange (SCE). We have observed that the spontaneous frequency of SCE in primary cultures of UM and UM‐derived cell lines is decreased below normal baseline levels, a phenomenon unique to UM when compared with multiple other cancers. This finding was specific to the tumor and not found in lymphocytes from the patients. Although we cannot exclude the possibility that low SCE (LSCE) is peculiar to the uveal melanocytes lineage, as it was consistently observed in all UM studied, regardless of other genetic defects, we propose that this phenomenon contributes to the molecular pathogenesis of UM. © 2010 Wiley‐Liss, Inc.
CNBP: A multifunctional nucleic acid chaperone involved in cell death and proliferation control
Authors: Calcaterra Nora B. , Armas Pablo , Weiner Andrea M. J. , Borgognone Mariana
Published: October 2010

Cellular nucleic acid binding protein (CNBP) has been implicated in vertebrate craniofacial development and in myotonic dystrophy type 2 (DM2) and sporadic inclusion body myositis (sIBM) human diseases. In these seemingly unrelated biological processes, CNBP appears to be involved in controlling cell death and proliferation rates. Low levels of CNBP may reduce rate of global protein synthesis, thereby reducing proliferation and increasing apoptosis. Conversely, CNBP might affect transcription of genes required for cell proliferation. Experimental evidences gathered so far make it difficult to ascertain or rule out any of these possibilities. Moreover, both possibilities may not be mutually exclusive. CNBP is a small and strikingly conserved single‐stranded nucleic acid binding protein that is able to bind DNA as well as RNA. CNBP has a broad spectrum of targets, ranging from regulatory sites in gene promoters to translational regulatory elements in mRNA untranslated regions. Biochemical experiments have recently shed light on the possible mechanism of action for CNBP, which may act as a nucleic acid chaperone catalyzing the rearrangement of G‐rich nucleic acid secondary structures likely relevant for transcriptional and/or translational gene regulation. This review focuses on the involvement of CNBP in vertebrate craniofacial development and human DM2 and sIBM diseases, as well as on the biochemical and structural features of CNBP and its cellular and molecular mechanism of action. © 2010 IUBMB IUBMB Life, 62(10): 707–714, 2010
Functional and structural aspects of helicobacter pylori acidic stress response factors
Authors: Zanotti Giuseppe , Cendron Laura
Published: October 2010

Helicobacter pylori is a striking example of adaptation of a bacterium to a very peculiar niche, the human stomach. Despite being a neutralophile, a sophisticated control of gene expression allows it to live and to proliferate in an environment that cycles from nearly neutral to very acidic. Despite the numerous studies performed on the mechanisms of acid adaptation, the physiological function of a large part of the genes products that are up‐regulated or down‐regulated is often not clear, in particular in the context of the response of the bacterium to an acidic stress. In this review, we discuss the molecular and functional aspects of some of the proteins that are commonly found overexpressed during the acid stress. © 2010 IUBMB IUBMB Life, 62(10): 715–723, 2010
A fitting formula for the falloff curves of unimolecular reactions, II: Tunneling effects
Authors: Zhang Peng , Law Chung K.
Published: October 2010

By taking into account effects of tunneling on the shape of the falloff curves of unimolecular reaction rate constants based on Troe's weak collision integral, a fitting formula for these curves is developed and then examined for several tunneling‐affected reactions. It is demonstrated that, compared to the widely used Troe's formula, the present expression not only substantially enhances the accuracy in fitting for tunneling‐affected reactions, but it is also computationally more efficient in its evaluation. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 43: 31–42, 2011
Monitoring fish oil volatiles to assess the quality of fish oil
Authors: Sullivan Jenna C. , Budge Suzanne M.
Published: October 2010

The fish oil industry is continuously growing; however there is a lack of analytical methods to assess fish oil quality that correlate with the results obtained through sensory testing. Solid phase microextraction (SPME) provides a means to monitor the concentration of oxidative volatiles in fish oil. Because volatile oxidation products are responsible for the off‐flavours found in oxidized fish oil, this technique may be used as a substitute for sensory panels. Principal component analysis (PCA), combined with sensory panels, can be used to determine the oxidation products that are most correlated with degradation of the sensory properties of the oil. This creates the potential for development of methods that can determine when the sensory qualities of oil have deteriorated beyond an acceptable level.
Controlled Fluorescence Resonance Energy Transfer from Multiple Fluorophores in Layer‐by‐Layer Assemblies
Authors: Kim Ki‐Se , Yoo Seong Il , Kim Minsoo , Sohn Byeong‐Hyeok
Published: October 2010

We demonstrate precise control of multiple FRET within LbL assemblies to produce simultaneous light emission with enhanced intensity from a single excitation with a blue wavelength. Three different fluorescent dyes were attached to neat polyelectrolytes and then incorporated into the LbL assembly. With designed deposition sequence, the layer of blue‐absorbing dyes was placed in the adjacent layer of green‐ and red‐emitting dyes, while the layers of emitting dyes were separated with each other beyond their Förster radius by inserting neat polyelectrolytes between them. The LbL assemblies not only allowed FRET from the absorbing dyes to the emitting dyes but also prohibited FRET between the emitting dyes to produce simultaneously enhanced green and red emission.

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Reversible Electrogelation in Poly(acrylic acid) Aqueous Solutions Triggered by Redox Reactions of Counterions
Authors: He Shuying , Ren Biye , Liu Xinxing , Tong Zhen
Published: October 2010

A facile, electrically induced reversible gelation in a PAA aqueous solution containing Fe ions has been realized. The PAA solution is converted into a homogeneous hydrogel when the ferrous ions are electro‐oxidized to ferric ions and this gel is restored to solution by electro‐reduction of the ferric ions to ferrous ions. This sol/gel transition is completely reversible by changing the electrode polarity. The stoichiometric relation between the gel weight and charge quantity is investigated by chronocoulometry and no saturation for gelation is observed even after 5 000 s. The cyclic voltammetry and polarization current have been measured on this gelation system to reveal the kinetic reversibility and redox species of the electrode process under specified electric potential.

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Synthesis and Photovoltaic Properties of Conjugated Copolymers with Benzo[1,2‐b:4,5‐b′]dithiophene and Bis(thiophene)phthalimide Units
Authors: Zhang Guobing , Fu Yingying , Zhang Qing , Xie Zhiyuan
Published: October 2010

Two new donor/acceptor copolymers PBDTPhBT1 and PBDTPhBT2 with alternating benzodithiophene (BDT) and bisthiophene‐phthalimide (PhBT) units were synthesized by Stille coupling reaction. The copolymers showed identical optical bandgaps of 1.98 eV. The HOMO energy levels are −5.35 and −5.32 eV for PBDTPhBT1 and PBDTPhBT2, respectively. The bulk heterojunction solar cell devices based on these copolymers as donors and PC71BM as acceptor displayed high open‐circuit voltages of 0.90–0.93 V and achieved power conversion efficiency of 1.54% under the illumination of AM 1.5, 100 mW · cm−2.

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Nanofibers by Green Electrospinning of Aqueous Suspensions of Biodegradable Block Copolyesters for Applications in Medicine, Pharmacy and Agriculture
Authors: Sun Jinyuan , Bubel Kathrin , Chen Fei , Kissel Thomas , Agarwal Seema , Greiner Andreas
Published: October 2010

Poly(hexamethylene adipate)‐PEO block copolymers (PHA‐b‐PEO) with different PEO contents were synthesized and processed to aqueous suspensions with high solid contents by a solvent displacement method followed by dialysis. The best suspension displayed a solid content of 16 wt.‐% and an average particle size of 108 nm. This suspension was mixed with a small amount of high molecular weight PEO and Brij78 and electrospun into corresponding nanofibers. After extraction with water, nanofibers of PHA‐b‐PEO were obtained. Electrospinning of aqueous suspensions of biodegradable polyesters alleviates concerns regarding safety, toxicology and environmental problems, which are associated with spinning of such polyesters from harmful organic solvents and thereby offers novel perspectives for applications in medicine, pharmacy and agriculture. Electrospinning of polymers from aqueous suspensions avoiding harmful organic solvents is suggested to be “green electrospinning”.

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Anionic Synthesis and Rheological Characterization of Poly(p‐methylstyrene) Model Comb Architectures with a Defined and Very Low Degree of Long Chain Branching
Authors: Kempf Michael , Barroso Vitor C. , Wilhelm Manfred
Published: October 2010

A method is presented for the synthesis of defined sparsely branched polystyrene‐based homopolymer model combs. By the use of poly(p‐methylstyrene) (PpMS) as backbone and side chains, a low, but well controlled amount of branching of typically less than 1 mol‐% (e.g., 1 branch per approx. 200 backbone C‐atoms) can be achieved. The used anionic synthesis offers full control of the molecular weight in combination with low polydispersity. Molecular weight and polydispersity were determined by SEC‐MALLS, confirming the well defined synthesis with low polydispersity ($\overline {{\rm M}} _{{\rm w}} /\overline {{\rm M}} _{{\rm n}} $ < 1.07). The melt rheological properties of the synthesized linear and comb polymers were obtained in both oscillatory shear and uniaxial extensional flow. Using the so‐called van Gurp–Palmen plot, clear differences between both synthesized topologies are clearly seen. The appearance of a second minimum for lower values of the complex modulus in shear is a clear indication of a second relaxation process attributable to the entangled side chains. The presence of the entangled side chains is responsible for the observed strain hardening obtained in extensional viscosity experiments, as compared to the linear polymers. These model samples open up the possibility to compare different advanced rheological methods, e.g., FT‐rheology or extensional rheology, towards limiting sensitivity.

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Anisotropic Micro‐ and Nano‐Capsules
Authors: Shchepelina Olga , Kozlovskaya Veronika , Kharlampieva Eugenia , Mao Wenbin , Alexeev Alexander , Tsukruk Vladimir V.
Published: October 2010

In this work, we introduce anisotropically shaped, ultrathin micro‐ and nano‐capsules fabricated by layer‐by‐layer approach. The original cubic and tetrahedral shapes of the template particles were replicated to produce hollow capsules with well‐defined edges. Introducing tannic acid as a component of LbL shells resulted in enhanced chemical stability of these hollow polymer structures under a wide pH range due to high pKa value. Computational studies demonstrated increased mechanical stability of the anisotropic capsules under osmotic pressure variation due to sharp edges and vertices acting as a reinforcing frame in contrast to spherical microcapsules that undergo random buckling.

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Interface microstructure of Stellite‐6 coatings on a 12%Cr steel after long term thermal exposure
Authors: Leinenbach C. , Al‐Badri A. , Roth M.
Published: October 2010

9–12% Cr steels are widely used in turbine parts in steam power plants because of their good mechanical properties and corrosion resistance at elevated temperatures. However, parts like valve seats and spindles are prone to oxidation, particle erosion or wear. This requires the application of protective coatings with adequate mechanical properties, wear and spalling resistance. Cobalt based coatings like Stellite 6 are applied for service temperatures up to 550°C, but steam temperatures of up to 700°C are planned for future power plants in order to decrease the CO2 exhaustion. In this work, the interfacial microstructure of Stellite 6 coated 12% Cr steel before and after long term annealing at elevated temperatures (up to 625°C and 10 000 h) was characterized. The experimental results were compared with the results of additional thermodynamic simulations. It could be shown that a thin (˜20 μm), hard and brittle interlayer with a complex microstructure forms during annealing, which can affect the long term integrity of such components.

9–12% Cr Stähle sind aufgrund ihrer guten mechanischen Eigenschaften und der relativ guten Korrosionsbeständigkeit bei erhöhten Temperaturen weitverbreitete Werkstoffe für Turbinenkomponenten in Dampfkraftwerken. Bestimmte Teile wie Ventilsitze oder ‐spindeln unterliegen einer ausgeprägten Beanspruchung verursacht durch Oxidation, Partikelerosion und Reibverschleiß. Aus diesem Grund werden häufig Schutzschichten mit angepassten mechanischen Eigenschaften, guten Verschleißeigenschaften sowie geringer Neigung zum Ablösen vom Grundwerkstoff eingesetzt. Beschichtungen aus Kobaltbasislegierungen wie z. B. Stellit 6 werden schon seit langen bei Betriebstemperaturen bis ca. 550°C verwendet. Für die Zukunft sind jedoch Frischdampftemperaturen von 700°C und mehr geplant, wodurch die CO2‐Emission von Kraftwerken reduziert werden soll. Im Rahmen dieser Arbeit wurde die grenzflächennahe Mikrostruktur von mit Stellit 6 beschichtetem 12%Cr‐Stahl vor und nach einer Langzeitauslagerung bis zu 10 000 h bei Temperaturen von bis zu 625°C charakterisiert. Die experimentellen Ergebnisse wurden mit den Ergebnissen ergänzender thermodynamischer Simulationen verglichen. Es konnte gezeigt werden, dass eine dünne (˜20 μm) harte und spröde Reaktionszwischenschicht mit komplexer Mikrostruktur während der Auslagerung entsteht, die sich negativ auf die Langzeitstabilität von entsprechenden Komponenten auswirken kann.
Very high cycle fatigue behavior of helical compression springs
Authors: Kaiser B. , Berger C.
Published: October 2010

Vorgestellt werden Vorgehensweise und Ergebnisse von Dauerschwingversuchen bis 109 Schwingspiele, die im Rahmen eines Forschungsvorhabens an zylindrischen Schraubendruckfedern mit zwei Drahtdurchmessern aus drei verschiedenen Werkstoffen vorgenommen wurden. Das Forschungsprojekt wurde zusammen mit einer Arbeitsgruppe des Verbands der Deutschen Federnindustrie (VDFi) initiiert und durchgeführt. Die Versuchsfedern wurden aus zwei ölschlussvergüteten SiCr‐ und SiCrV‐legierten Ventilfederstahldrähten und aus einem nichtrostenden Federstahldraht mit Drahtdurchmessern von 1,6 mm und 3,0 mm hergestellt und abschließend kugelgestrahlt. Die gebrochenen Federn wurden stereo‐ und rasterelektronenmikroskopisch sowie metallographisch untersucht, um das Bruchverhalten und die Schädigungsmechanismen zu analysieren. Die Versuchsfedern zeigen unterschiedliche Schwingfestigkeitseigenschaften und Versagensmechanismen im Bereich extrem hoher Schwingspielzahlen.

This paper reports on procedure and research results of long‐term fatigue tests up to a number of 109 cycles on helical compression springs with two basic dimensions, made of three different spring materials. The corresponding research project was initiated together with a working group of the Association of German Springs' Industry (VDFi – Verband der Deutschen Federnindustrie). The test springs were manufactured of two oil hardened and tempered SiCr‐ and SiCrV‐alloyed valve spring steel wires and of one stainless steel wire with diameters of 1.6 mm and 3.0 mm and finally shot peened. Fractured test springs were investigated by stereo‐microscope, Scanning Electron Microscope (SEM) and by means of metallographic microsections in order to analyse the fracture behavior and the failure mechanisms. It becomes obvious that the various spring types in test exhibit different fatigue properties and also different failure mechanisms in the VHCF regime.
Investigating of polysulfide and epoxy‐polysulfide copolymer curing
Authors: Abdouss M. , Farajpour T. , Derakhshani M.
Published: October 2010

Polysulfide can be cured in various methods. In this work, the effect of various oxidative curing agents (manganese dioxide and para quinonedioxime) in presence of curing accelerator (Diphenylguanidine) on mechanical‐dynamical properties and cure time of polysulfide resin (G4) was investigated. Results showed that mentioned oxidative curing agents have no remarkable effect on mechanical properties and cure time. But preferred method is preparation of polysulfide‐epoxy copolymer. This copolymer is a new class of liquid polymer composition containing block copolymers, with alternating blocks of polysulfide and polyepoxide. in different epoxy/polysulfide ratio, the epoxy‐polysulfide copolymer showd different tensile strenght, elongation, hardness, gel time, viscosity and Tg, but epoxy free polysulfide approximately revealed constant mechanical and dynamical properties so that epoxidized polysulfide had excellent mechanical properties and suitable curring times in comparison with those samples which were cured in other methods. FT‐IR spectroscopy, viscometry and GPC were used to verify the formation of epoxy‐polysulfide copolymer. Results obtained from DMTA and SEM showed that phase separation of epoxy resin from the copolymer matrix took place and The glass transition temperature (Tg) of the cured copolymer was between the cured epoxy and polysulfide glass transition temperatures.
Decreased striatal dopamine receptor binding in primary focal dystonia: A D2 or D3 defect?
Authors: Karimi Morvarid , Moerlein Stephen M. , Videen, Tom O. , Luedtke Robert R. , Taylor Michelle , Mach Robert H. , Perlmutter Joel S.
Published: October 2010

Dystonia is an involuntary movement disorder characterized by repetitive patterned or sustained muscle contractions causing twisting or abnormal postures. Several lines of evidence suggest that abnormalities of dopaminergic pathways contribute to the pathophysiology of dystonia. In particular, dysfunction of D2‐like receptors that mediate function of the indirect pathway in the basal ganglia may play a key role. We have demonstrated with positron emission tomography that patients with primary focal cranial or hand dystonia have reduced putamenal specific binding of [18F]spiperone, a nonselective D2‐like radioligand with nearly equal affinity for serotonergic 5‐HT(2A) sites. We then repeated the study with [18F]N‐methyl‐benperidol (NMB), a more selective D2‐like receptor radioligand with minimal affinity for 5‐HT(2A). Surprisingly, there was no decrease in NMB binding in the putamen of subjects with dystonia. Our findings excluded reductions of putamenal uptake greater than 20% with 95% confidence intervals. The analysis of the in vitro selectivity of NMB and spiperone demonstrated that NMB was highly selective for D2 receptors relative to D3 receptors (200‐fold difference in affinity), whereas spiperone has similar affinity for all three of the D2‐like receptor subtypes. These findings when coupled with other literature suggest that a defect in D3, rather than D2, receptor expression may be associated with primary focal dystonia. © 2010 Movement Disorder Society.
Apomorphine effect on pain threshold in Parkinson's disease: A clinical and positron emission tomography study
Authors: Dellapina Estelle , Gerdelat‐Mas Angélique , Ory‐Magne Fabienne , Pourcel Laure , Galitzky Monique , Calvas Fabienne , Simonetta‐Moreau Marion , Thalamas Claire , Payoux Pierre , Brefel‐Courbon Christine
Published: October 2010

Patients with Parkinson's disease (PD) frequently experience pain that could be in part due to central modification of nociception. In this randomized controlled double blind study, we compared the effect of apomorphine versus placebo on pain thresholds and pain‐induced cerebral activity in 25 patients with PD. Subjective pain threshold (using thermal stimulation, thermotest), objective pain threshold (nociceptive flexion reflex), and cerebral activity (HO PET) during noxious and innocuous stimulations were performed. Neither subjective nor objective pain thresholds nor pain activation profile were modified by apomorphine compared with placebo in 25 PD patients. Apomorphine has no effect on pain processing in PD. We suggest that other monoamine systems than dopaminergic system could be involved. © 2010 Movement Disorder Society.
Exercise elevates dopamine D2 receptor in a mouse model of Parkinson's disease: In vivo imaging with [18F]fallypride
Authors: Vučcković Marta G. , Li Quanzheng , Fisher Beth , Nacca Angelo , Leahy Richard M. , Walsh John P. , Mukherjee Jogesh , Williams Celia , Jakowec Michael W. , Petzinger Giselle M.
Published: October 2010

The purpose of the current study was to examine changes in dopamine D2 receptor (DA‐D2R) expression within the basal ganglia of MPTP mice subjected to intensive treadmill exercise. Using Western immunoblotting analysis of synaptoneurosomes and in vivo positron emission tomography (PET) imaging employing the DA‐D2R specific ligand [18F]fallypride, we found that high intensity treadmill exercise led to an increase in striatal DA‐D2R expression that was most pronounced in MPTP compared to saline treated mice. Exercise‐induced changes in the DA‐D2R in the dopamine‐depleted basal ganglia are consistent with the potential role of this receptor in modulating medium spiny neurons (MSNs) function and behavioral recovery. Importantly, findings from this study support the rationale for using PET imaging with [18F]fallypride to examine DA‐D2R changes in individuals with Parkinson's Disease (PD) undergoing high‐intensity treadmill training. © 2010 Movement Disorder Society.
Neuropsychological correlates of mild to severe hallucinations in Parkinson's disease
Authors: Llebaria Gisela , Pagonabarraga Javier , Martínez‐Corral Mercè , García‐Sánchez Carmen , Pascual‐Sedano Berta , Gironell Alexandre , Kulisevsky Jaime
Published: October 2010

The development of visual hallucinations (VH) is a frequent complication of Parkinson's disease (PD). Presence of hallucinations is one of the main risk factors associated with dementia, and severity progression of VH mainly contributes to impaired quality of life in PD. The neuropsychological features associated with severity progression of VH are unknown and might help to detect patients at risk of a more severe outcome. We aimed to explore the neuropsychological deficits associated with the different types of VH observed in PD, from minor hallucinations to well‐formed VH with loss of insight. Prospective study of 57 PD patients with (n = 29) and without VH (n = 28) matched for age, education, antiparkinsonian medications, and disease duration. Description of VH was assessed by the Hallucinations and Psychosis item of the MDS‐UPDRS. Cognition was assessed with the Parkinson's Disease‐Cognitive Rating Scale (PD‐CRS) and the Mattis Dementia Rating Scale (MDRS). Patients with minor VH did not differ from patients without VH in any cognitive domain. PD patients with major VH and insight retained performed worse on the action verbal fluency task (P < 0.04), and patients with VH and loss of insight showed a greater impairment on the PD‐CRS posterior cortical score (P = 0.021) and the clock copying item (P = 0.01). A double dissociation was found in the neuropsychological profile of patients with VH with and without loss of insight. While the presence of major VH with insight retained appeared related to a predominant frontal‐striatal impairment, loss of insight was characterized by further impairment of cognitive functions related to posterior cortical areas. A comprehensible continuum pattern of clinical relationships emerged among VH and cognitive functioning in PD. © 2010 Movement Disorder Society.
Dopamine boosts memory for angry faces in Parkinson's disease
Authors: Subramanian Leena , Hindle John Vincent , Jackson Margaret Cecilia , Linden David E. J.
Published: October 2010

The influence of emotional context on cognitive operations is of fundamental importance for the evolution of higher cognitive functions and their disturbance in neuropsychiatric disorders. The dopamine pathways projecting to prefrontal cortex and the basal ganglia are assumed to play a major role in such emotion‐cognition interactions. Here we provide evidence for such a role by studying working memory for emotional faces in patients with Parkinson's Disease. We studied 25 patients with Parkinson's disease during their on and off medication states. Faces with emotional expressions (happy, angry, sad, neutral or fearful) were shown and the participants had to remember and later recall the identity of the faces ignoring the expressions. We found that dopaminergic medication enhances working memory for angry faces and suppresses it for sad faces. The results elucidate neurochemical mechanisms for the saliency of threatening information and support cognitive explanations of the antidepressant effects of dopamine. They also suggest a role for dopamine in changing emotional‐cognitive biases rather than as a generic cognitive enhancer. © 2010 Movement Disorder Society.
Fall risk assessment using the Tinetti mobility test in individuals with Huntington's disease
Authors: Kloos Anne D. , Kegelmeyer Deb A. , Young Gregory S. , Kostyk Sandra K
Published: October 2010

The Tinetti Mobility Test (TMT) is a clinical balance and gait test that predicts fall risk in the elderly. This study examined the concurrent validity, usefulness of the TMT as a fall risk screening tool, and the potential ability of the TMT to predict falls in individuals with Huntington's disease (HD). Data from a retrospective review of 94 patient records were used. TMT scores were correlated with Unified Huntington Disease Rating Scale (UHDRS) motor scores. The ability of the TMT to accurately assess fall risk was determined using validity index measures. Logistic regression was used to assess the ability of the TMT to predict falls. TMT scores correlated with UHDRS motor scores (rs = −0.751, P < 0.0001). Using a cutoff value of 21, the TMT had a sensitivity of 74% and a specificity of 60% to identify fallers. Lower TMT scores and younger age were significant predictors of falls. The TMT is a valid tool for assessing balance and gait status and fall risk of individuals with HD. © 2010 Movement Disorder Society.
Breaking communication barriers for RA patients of south Asian origin: the use of a bilingual educational audio CD and linguistically appropriate peer support and education
Authors: Kumar Kanta , John Holly , Gordhan Chandrika , Situnayake Deva , Raza Karim , Bacon Paul A.
Published: October 2010

Background. People from the Indian subcontinent represent one of the largest ethnic groups in the UK. Patient education resources are required to address language barriers, poor literacy and (potentially discordant) cultural beliefs. We have investigated a novel strategy to meet this need.

Methods. Rheumatoid arthritis (RA) patients of South Asian origin who prefer to communicate in a South Asian language were invited to a face‐to‐face interaction with a trained patient volunteer to provide linguistically appropriate peer support and education, and given a bilingual educational audio CD. Qualitative methods were used to assess this approach; three focus groups were held and 15 patients participated in total.

Results. Four important themes were identified: (1) The need for information about RA; all patients agreed that this was vital to learn how to live with their chronic disease. (2) Currently available approaches to education; particular concerns related to a lack of time in clinic, language barriers, difficulties in communicating via interpreters and that most written information was available only in English. (3) Support provided by a trained patient volunteer; patients appreciated that they were listened to, and were motivated by the volunteers' positive attitude. (4) The usefulness of the audio CD; patients appreciated that information was presented in a language they could understand, via a convenient medium and which offered a helpful perspective on their illness.

Conclusions. This approach is a successful way of delivering information and encouraged patients from a difficult‐to‐reach community to become more involved in their disease management. Copyright © 2010 John Wiley & Sons, Ltd.
Effect of various types of interaction on the stability of some ternary interpolymer complexes involving poly(ethylene imine), poly(acrylic acid) and poly(ethylene glycol)
Authors: Vasheghani F Bahman , Rajabi Farzaneh Hosseinpour , Ahmadi Mohammad Hossein , Zenooz Nasaer
Published: October 2010

The effect of various types of interaction on the stability of multi‐component interpolymer complexes was studied for some three‐component interpolymer complexes involving poly(ethylene imine), poly(acrylic acid) and poly(ethylene glycol). The degree of linkage (θ), stability constant (K) and related thermodynamic parameters (e.g. ΔH0 and ΔS0) of these complexes were determined at several temperatures and compared for various complexation systems. The comparative study indicated considerable difference in the values of these parameters, which is explained in terms of various modes of interaction between the components. Copyright © 2010 Society of Chemical Industry
Synthesis of i‐PP‐based functional block copolymer by a facile combination of styryl‐capped i‐PP and ATRP
Authors: Huang Huahua , Niu Hui , Dong Jin‐Yong
Published: October 2010

This article demonstrates a facile and efficient method to combine olefin coordination polymerization with atom transfer radical polymerization (ATRP) for the synthesis of isotactic polypropylene (i‐PP)‐based functional diblock copolymers. The chemistry involves a styryl‐capped i‐PP precursor prepared through the controlled consecutive chain transfer reaction, first to 1,2‐bis(4‐vinylphenyl)ethane and then to hydrogen in propylene polymerization mediated by an isospecific metallocene catalyst. The i‐PP precursor can be quantitatively transformed into i‐PP terminated with a 1‐chloroethylbezene group (i‐PP‐t‐Cl) by a straightforward hydrochlorination process using hydrogen chloride. With the resultant i‐PP‐t‐Cl as a macroinitiator of ATRP, methyl methacrylate (MMA) polymerization was exemplified in the presence of CuBr/pentamethyldiethylenetriamine, preparing i‐PP‐b‐PMMA copolymers of different PMMA contents. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Investigating the effect of nanolayered silicates on blend segmental dynamics and minor component relaxation behavior in poly(ethylene oxide)/poly(methyl methacrylate) miscible blends
Authors: Jeddi Kazem , Qazvini Nader Taheri , Hassan Jafari Seyed , Ali Khonakdar Hossein , Seyfi Javad , Reuter Uta
Published: October 2010

Polymer–silicate nanocomposites based on poly (ethylene oxide), PEO, poly(methyl methacrylate), PMMA, and sodium montmorillonite clay were fabricated and characterized to investigate the effect of nanolayered silicates on segmental dynamics of PEO/PMMA blends. X‐ray results indicate the formation of an exfoliated morphology in the nanocomposites. At low silicate contents, an enhancement in segmental dynamics of blend nanocomposites and also PEO, minor component in blend, is observed at temperature region below blend glass transition. This result can be attributed to the improvement of the confinement effect of rigid PMMA matrix on the PEO chains by introducing a low amount of layered silicates. On the other hand, at high silicate contents, an enhancement in segmental dynamics of blend nanocomposites and PEO is observed at temperature region above blend glass transition. This behavior could be interpreted based on the reduction of monomeric friction between two polymer components, which can facilitate segmental motions of blend components in nanocomposite systems. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
Structures of parasitic CDPK domains point to a common mechanism of activation
Authors: Wernimont Amy K. , Amani Merhnaz , Qiu Wei , Pizarro Juan C. , Artz Jennifer D. , Lin Yu‐Hui , Lew Jocelyn , Hutchinson Ashley , Hui Raymond
Published: October 2010

We recently determined the first structures of inactivated and calcium‐activated calcium‐dependent protein kinases (CDPKs) from Apicomplexa. Calcium binding triggered a large conformational change that constituted a new mechanism in calcium signaling and a novel EF‐hand fold (CAD, for CDPK activation domain). Thus we set out to determine if this mechanism was universal to all CDPKs. We solved additional CDPK structures, including one from the species Plasmodium. We highlight the similarities in sequence and structure across apicomplexan and plant CDPKs, and strengthen our observations that this novel mechanism could be universal to canonical CDPKs. Our new structures demonstrate more detailed steps in the mechanism of calcium activation and possible key players in regulation. Residues involved in making the largest conformational change are the most conserved across Apicomplexa, leading us to propose that the mechanism is indeed conserved. CpCDPK3_CAD and PfCDPK_CAD were captured at a possible intermediate conformation, lending insight into the order of activation steps. PfCDPK3_CAD adopts an activated fold, despite having an inactive EF‐hand sequence in the N‐terminal lobe. We propose that for most apicomplexan CDPKs, the mode of activation will be similar to that seen in our structures, while specific regulation of the inactive and active forms will require further investigation. Proteins 2011. © 2010 Wiley‐Liss, Inc.
Role of conformational sampling in computing mutation‐induced changes in protein structure and stability
Authors: Kellogg Elizabeth H. , Leaver‐Fay Andrew , Baker David
Published: October 2010

The prediction of changes in protein stability and structure resulting from single amino acid substitutions is both a fundamental test of macromolecular modeling methodology and an important current problem as high throughput sequencing reveals sequence polymorphisms at an increasing rate. In principle, given the structure of a wild‐type protein and a point mutation whose effects are to be predicted, an accurate method should recapitulate both the structural changes and the change in the folding‐free energy. Here, we explore the performance of protocols which sample an increasing diversity of conformations. We find that surprisingly similar performances in predicting changes in stability are achieved using protocols that involve very different amounts of conformational sampling, provided that the resolution of the force field is matched to the resolution of the sampling method. Methods involving backbone sampling can in some cases closely recapitulate the structural changes accompanying mutations but not surprisingly tend to do more harm than good in cases where structural changes are negligible. Analysis of the outliers in the stability change calculations suggests areas needing particular improvement; these include the balance between desolvation and the formation of favorable buried polar interactions, and unfolded state modeling. Proteins 2011. © 2010 Wiley‐Liss, Inc.
Effect of Candidatus Liberibacter asiaticus infection on susceptibility of Asian citrus psyllid, Diaphorina citri, to selected insecticides
Authors: Tiwari Siddharth , Pelz‐Stelinski Kirsten , Stelinski Lukasz L
Published: October 2010

BACKGROUND: In the present investigation, the effect of Candidatus Liberibacter asiaticus (Las), a bacterium considered to be responsible for causing huanglongbing (HLB) disease in citrus, on the physiology of its vector, the Asian citrus psyllid (ACP) Diaphorina citri Kuwayama, was determined. Specifically, the effects of Las infection on the susceptibility of ACP to selected insecticides were determined. Furthermore, total protein content and general esterase activity were quantified in Las‐infected and uninfected ACP to gain insight into the possible mechanism(s) responsible for altered susceptibility to insecticides owing to Las infection.

RESULTS: LC50 values were significantly lower in Las‐infected than in uninfected ACP adults for chlorpyrifos and spinetoram. Furthermore, there was a general trend towards lower LC50 values for three other insecticides for Las‐infected ACP; however, the differences were not statistically significant. Total protein content (µg mL−1) was significantly lower in Las‐infected (23.5 ± 1.3 in head + thorax; 27.7 ± 1.9 in abdomen) than in uninfected (29.7 ± 2.1 in head + thorax; 35.0 ± 2.3 in abdomen) ACP. Likewise, general esterase enzyme activity (nmol min−1 mg−1 protein) was significantly lower in Las‐infected (111.6 ± 4.5 in head + thorax; 109.5 ± 3.7 in abdomen) than in uninfected (135.9 ± 7.5 in head + thorax; 206.1 ± 23.7 in abdomen) ACP.

CONCLUSION: Susceptibility of ACP to selected insecticides from five major chemistries was greater in Las‐infected than in uninfected ACP. The lower total protein content and reduced general esterase activity in Las‐infected than in uninfected ACP may partly explain the observed higher insecticide susceptibility of Las‐infected ACP. Copyright © 2010 Society of Chemical Industry