bluuebunny/crossref_metadata_2025 huggingface dataset:
A theoretical density functional study of association of Zn2+ with oxazolidine and its thio derivatives in the gas phase
Authors: Safi Zaki S. , Lamsabhi Al Mokhtar
Published: January 2010

We have performed density functional theory (DFT) calculations in order to study the gas‐phase interaction of oxo‐ and thio‐oxazolidine derivatives with Zn2+. The calculations were performed at B3LYP/6‐311+(2df,2p) level of theory. It has been found, in all cases, that the direct association of Zn2+ with the carbonyl and thiocarbonyl groups takes place at the heteroatom attached to position 2 irrespective of its nature. This preference has been attributed to the resonance effects caused by the nearest heteroatoms (oxygen and nitrogen). The most stable complexes correspond to structures with Zn2+ bridging between the heteroatom at position 2 or 4 of the 4‐ or 2‐enol (or the 4‐ or 2‐enethiol) tautomer and the dehydrogenated ring nitrogen atom, N3. Zn2+ association has a clear catalytic effect on the tautomerization processes which connect the oxo–thione forms with the enol–enethiol tautomers. Hence, although the enol–enethiol tautomers of oxazolidine and its thio derivatives should not be observed in the gas phase, the corresponding Zn2+ complexes are the most stable species and should be accessible, because the tautomerization barriers are smaller than the Zn2+ binding energies. Copyright © 2010 John Wiley & Sons, Ltd.
A child's asthma quality of life rating does not significantly influence management of their asthma
Authors: Mandhane Piush J. , McGhan Shawna L. , Sharpe Heather M. , Wong Eric , Hessel Pat A. , Befus A. Dean , Majaesic Carina
Published: January 2010

Background

Children of parents who perceive their children have increased asthma severity use more medical services and reliever medication.

Methods

A randomized control trial of the Roaring Adventures of Puff (RAP) education program was completed among 287 grade 2–5 children with asthma. Parents and children completed a quality of life (QOL) questionnaire pre‐intervention, 6 and 12 months post‐intervention. We hypothesized that RAP altered how parent's assessed their child's QOL with a resultant change in asthma management.

Results

Pre‐intervention, parents rated their child's overall QOL higher than their child (parent 5.41 [95% CI 5.24, 5.58] vs. child 4.54 [95% CI 4.32, 4.75]; P < 0.001: paired t‐test). For every point increase in the parent's overall QOL score, the child was 36% less likely to receive inhaled corticosteroids in the prior 2 weeks (OR 0.64, 95% CI 0.46, 0.88; P = 0.024) and 46% less likely to have missed school due to asthma in the prior 6 months (OR 0.54, 95% CI 0.36, 0.82; P = 0.016: logistic regression). The child's QOL assessment, beyond that provided by their parent, was not associated with the asthma management outcomes examined. The RAP program decreased parent's symptoms QOL assessment by an improvement of 0.45 on a 7‐point scale greater than control at 6 months (95% CI −0.81, −0.09; P = 0.06). Moreover, the RAP interaction on parent symptoms rating was important in determining whether the child received a short‐acting beta‐agonist in the prior 2 weeks (P = 0.05).

Conclusions

Parent's QOL perception, and not the child's, is associated with asthma management. RAP decreased the parent's QOL symptoms assessment and was important in determining the child's asthma management. Pediatr Pulmonol. 2010; 45:141–148. © 2010 Wiley‐Liss, Inc.
A versatile selection system for folding competent proteins using genetic complementation in a eukaryotic host
Authors: Lyngsø Christina , Kjaerulff Søren , Müller Sven , Bratt Tomas , Mortensen Uffe H. , Dal Degan Florence
Published: January 2010

Recombinant expression of native or modified eukaryotic proteins is pivotal for structural and functional studies and for industrial and pharmaceutical production of proteins. However, it is often impeded by the lack of proper folding. Here, we present a stringent and broadly applicable eukaryotic in vivo selection system for folded proteins. It is based on genetic complementation of the Schizosaccharomyces
pombe growth marker gene invertase fused C‐terminally to a protein library. The fusion proteins are directed to the secretion system, utilizing the ability of the eukaryotic protein quality‐control systems to retain misfolded proteins in the ER and redirect them for cytosolic degradation, thereby only allowing folded proteins to reach the cell surface. Accordingly, the folding potential of the tested protein determines the ability of autotrophic colony growth. This system was successfully demonstrated using a complex insertion mutant library of TNF‐α, from which different folding competent mutant proteins were uncovered.
Selective patterning of covalent molecular grafting on doped amorphous silicon templates
Authors: Sabbah Hussein , Chu Virginia , Conde Joao Pedro , Ababou‐Girard Soraya , Delhaye Thomas , LePottier Arnaud , Solal Francine , Godet Christian
Published: January 2010

Linear alkene molecules have been covalently immobilized on amorphous silicon surfaces. The larger thermal reactivity of n+‐doped vs. nominally undoped a‐Si:H surfaces towards perfluorodecene (PFD) molecules in the gas phase has been exploited to investigate a selective patterning of molecular grafting on a previously defined template of doped / undoped regions. PFD has been chosen to obtain hydrophobic monomolecular layers with fluorine labelling, useful for photoelectron spectroscopy (XPS) and NanoSIMS imaging.

The template was obtained by growing undoped a‐Si:H on top of n+ a‐Si‐H, and defining 40 μm‐edge patterns of undoped a‐Si:H by reactive ion etching in a (CF4, O2) mixture. After native oxide removal, the patterned surface was exposed to PFD at 230 °C. NanoSIMS images, taken at increasing Cs+ irradiation doses, show the expected 19F and 28Si contrast on as‐grafted surfaces; this contrast disappears after ∼340 seconds Cs+ irradiation, corresponding to the desorption of the PFD monomolecular layer. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Columnar structured amorphous carbon nitride films
Authors: Aono Masami , Kikuchi Shunsuke , Tamura Naoyuki , Kitazawa Nobuaki , Watanabe Yoshihisa , Nitta Shoji
Published: January 2010

Columnar structured amorphous carbon nitride films were deposited by reactive radio frequency magnetron sputtering from a graphite target in glow discharge plasma of nitrogen. The columnar structure was observed in all specimens of the amorphous carbon nitride (a‐CNx) films deposited on substrates of crystalline Si and quartz glass within substrate temperatures between RT and 853 K in nitrogen gas pressure of 0.12 to 0.8 Torr. The average diameter of the columns obtained from SEM was found to be about 40 nm. The results of XRD and FE‐TEM confirmed the columns were amorphous materials. However, the electrical properties reflected clearly the heterogeneous structure of a‐CNx films, i.e., the resistivity in the vertical to a‐CNx columns was lower as compared with that in the horizontal direction (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Conductivity oscillations in Ge2Sb2Te5 films stimulated by phase transformations
Authors: Kozyukhin Sergey , Voronkov Edward , Egarmin Konstantin
Published: January 2010

The conductivity oscillations during phase transformations in a Ge2Sb2Te5 thin films, stimulated by a short electric pulse, have been studied. The faded oscillations exist even after a switching pulse off, if a pulse time is longer than a sample thermal time constant. A fixed electrical bias applied to a sample allows to record and controlling the appearance of oscillations. The observed phenomenon is explained by interactions of exothermic and endothermic processes during transformations that take place in different local regions of the sample. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of light soaking on CPM absorption spectra in silicon films with mixed amorphous‐nanocrystalline structure
Authors: Kazanskii Andrey , Kong Guanglin , Zeng Xiangbo , Hao Huiying
Published: January 2010

The effect of light soaking on photoconductivity and DC CPM absorption spectra in hydrogenated silicon films with mixed amorphous‐nanocrystalline structure studied. A series of biphase silicon films were deposited using very high frequency plasma‐enhanced chemical vapor deposition (VHF‐PECVD) technique with hydrogen dilution ratios of silane from 10 to 40. The rate of photoconductivity decrease with light soaking time was increasingly suppressed as crystalline volume fraction in the film increased. For silicon films with low crystalline volume fraction, light soaking produced an increase in CPM absorption in the “defect” region of the spectrum at photon energies below 1.4 eV. For silicon films with high crystalline volume fraction, there was no substantial difference between CPM absorption spectra measured before and after light soaking. However, for silicon films with intermediate crystalline grain volume fraction, CPM absorption measurements revealed a dramatic increase in CPM absorption in the energy region (1.2 – 1.7) eV after light soaking. The results obtained indicate a possibility of light‐induced increase in the contribution of crystalline phase to the photoconductivity of silicon films with mixed amorphous‐nanocrystalline structure (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The kinetics of light‐induced defect creation in hydrogenated polymorphous silicon – stretched exponential relaxation
Authors: Morigaki K. , Hikita H. , Takeda K. , Cabarrocas P. Roca i
Published: January 2010

The growing curve of light‐induced dangling bonds under illumination has been observed for various intensities of illumination in hydrogenated polymorphous silicon. It is fitted to a stretched exponential function with two parameters β and τ. The experimental results on the values of β and τ as functions of saturated dangling bond density Nss are compared with those calculated on the basis of our model for light‐induced defect creation in a‐Si:H. This comparison as well as the experimental result on saturated dangling bond density as a function of generation rate of free carriers is consistent with our model (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Inline deposition of microcrystalline silicon solar cells using a linear plasma source
Authors: Zimmermann T. , Strobel C. , Albert M. , Beyer W. , Gordijn A. , Flikweert A. J. , Kuske J. , Bartha J. W.
Published: January 2010

In this work we investigate and discuss the influence of a dynamic inline deposition process on the properties of microcrystalline silicon solar cells. A VHF‐PECVD inline deposition system with linear plasma sources working at 81.36 MHz was employed for film preparation. We focused on the dynamic deposition of solar cells at different substrate carrier speeds. The solar cell properties as well as the crystallinity were determined and analyzed. Our best cells so far showed efficiencies of 6.3% at a static deposition rate of 0.43 nm/s. For increasing substrate carrier speeds no negative trend could be observed. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantum chemical modelling of Si sub‐surface amorphisation due to incorporation of H atoms and its stabilisation by O atoms
Authors: Pushkarchuk Alexander , Saad Anis , Pushkarchuk Vadim , Fedotov Alexander , Mazanik Alexander , Zinchuk Olga , Turishchev Sergey
Published: January 2010

Here we present the results of systematic simulating studies of atomic configurations in silicon “surface clusters” with different numbers (per cluster) of interstitial H and O atoms as impurities, obtained by semi‐empirical (PM3) and DFT quantum‐chemical methods. The aim of modeling was to study the near‐surface region Si amorphization caused by H‐incorporation (from H‐plasma, for example) and changes in the atomic structure of this amorphized sub‐surface region by additionally incorporated O‐atoms. A set of SixHy[HLOM] clusters was used in order to reproduce a local atomic structure of H‐ or H‐O‐containing complexes with different numbers of impurity atoms per cluster for the corresponding Si (111) and Si (100) near‐surface regions. Here x ‐ number of Si atoms, y ‐ number of H atoms which saturate dangling bonds at the cluster surface, L ‐ number of incorporated H atoms which create hydrogen‐containing defect complexes, M ‐ number of O atoms incorporated in hydrogen‐containing complexes. The optimization procedure, using the PM3 and DFT levels quantum chemical theory geometry optimisation of all Si clusters, allowed comparison of changes in the atomic structures of Si surface and sub‐surface regions with different configurations of Si‐H and Si‐H‐O impurity complexes (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
N and P type top‐gate microcrystalline silicon TFTs processed at low temperature (T < 200 °C) on the same glass substrate
Authors: Souleiman Isman , Kandoussi Khalid , Belarbi Khaled , Cherfi Rabah , Fedala Abdlkrim , Coulon Nathalie , Simon Claude , Mohammed‐Brahim Tayeb
Published: January 2010

Low temperature deposited RF‐PECVD undoped, arsenic and boron doped μc‐Si:H films are used to fabricate the N‐type and P‐type TFTs on the same glass substrate. The transistors have a coplanar top gate configuration and a silicon nitride as gate insulator. The 50 nm thin μc‐Si:H active layer showed a thermal activation energy of the conductivity of 0.57 eV and a crystalline volume fraction of 70%. The arsenic and boron doped μc‐Si:H source/drain contact layers showed a conductivity at room temperature of 5 S/cm and 2.5 S/cm respectively. These TFTs showed a field effect mobility of 0.3 cm2/V.s for electrons and 0.2 cm2/V.s for holes and an (ION/IOFF) current ratio of 107. These results show the possibility to produce CMIS (Complementary Metal Insulator Semiconductor) inverter with silicon nitride as gate insulator at very low temperature compatible with foreign substrates such as flexible plastics or textiles. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Microcrystalline silicon thin film solar cells with microcrystalline silicon carbide window layers and silicon absorber layers both prepared by Hot‐Wire CVD
Authors: Chen Tao , Huang Yuelong , Yang Deren , Carius Reinhard , Finger Friedhelm
Published: January 2010

Microcrystalline silicon carbide (μc‐SiC:H) window layers prepared by Hot‐Wire Chemical Vapor Deposition (HWCVD) were applied in thin film silicon solar cells with microcrystalline silicon (μc‐Si:H) absorber layers. The intrinsic μc‐Si:H absorber was prepared by HWCVD or Plasma Enhanced Chemical Vapor Deposition (PECVD) over a wide range of crystalline volume fractions. With both types of absorber layers high solar cell short circuit current densities (jSC) can be obtained due to the highly transparent μc‐SiC:H window layer and better optical matching. Using the μc‐Si:H absorber prepared by HWCVD yields an additional improvement in the open circuit voltage (VOC) of about 20 mV. A 1 μm thick μc‐Si:H cell was obtained with VOC = 549 mV and jSC = 25.6 mA/cm2 resulting in an efficiency of 9.2%. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sensitivity experiments for ensemble forecasts of the extratropical transition of typhoon Tokage (2004)
Authors: Anwender Doris , Jones Sarah C. , Leutbecher Martin , Harr Patrick A.
Published: January 2010

The extratropical transition (ET) of tropical cyclones often has a detrimental impact on predictability in the vicinity of the event and downstream. Ensemble forecasts provide an appropriate means by which to investigate both the uncertainty and the dynamical development leading to the different ET scenarios. Sensitivity experiments are presented using the European Centre for Medium‐Range Weather Forecasts (ECMWF) ensemble prediction system (EPS) to investigate different methods of perturbing the ensemble forecast of the ET of Typhoon Tokage (2004). During ET these perturbations have a notable impact on the ensemble spread representing the uncertainty. Three experiments were performed: one of them without singular vectors (SVs) targeted on the tropical cyclone, the second without stochastic physics and the third excluding both perturbation methods.

The targeted perturbations are most important for sufficient spread in track and intensity. Without the targeted perturbations, the analysis is not contained within the ensemble spread. Stochastic physics leads to stronger reintensification of the ensemble members after ET. The higher track spread leads to higher variability in processes such as lower tropospheric latent heat release. This can be related to a higher spread in the upper‐level midlatitude flow for both perturbation methods. A connection is drawn between the strength of ET and the modification of the downstream midlatitude flow pattern. The uncertainty due to the targeted perturbations propagates downstream with a Rossby wave train excited during Tokage's ET. For the case of stochastic physics, the uncertainty spreads to the ridge directly downstream of the ET system but is not evident further downstream. Copyright © 2010 Royal Meteorological Society
Doppler lidar measurements of oriented planar ice crystals falling from supercooled and glaciated layer clouds
Authors: Westbrook C. D. , Illingworth A. J. , O'Connor E. J. , Hogan R. J.
Published: January 2010

The properties of planar ice crystals settling horizontally have been investigated using a vertically pointing Doppler lidar. Strong specular reflections were observed from their oriented basal facets, identified by comparison with a second lidar pointing 4° from zenith. Analysis of 17 months of continuous high‐resolution observations reveals that these pristine crystals are frequently observed in ice falling from mid‐level mixed‐phase layer clouds (85% of the time for layers at −15 °C). Detailed analysis of a case study indicates that the crystals are nucleated and grow rapidly within the supercooled layer, then fall out, forming well‐defined layers of specular reflection. From the lidar alone the fraction of oriented crystals cannot be quantified, but polarimetric radar measurements confirmed that a substantial fraction of the crystal population was well oriented. As the crystals fall into subsaturated air, specular reflection is observed to switch off as the crystal faces become rounded and lose their faceted structure.

Specular reflection in ice falling from supercooled layers colder than −22 °C was also observed, but this was much less pronounced than at warmer temperatures: we suggest that in cold clouds it is the small droplets in the distribution that freeze into plates and produce specular reflection, whilst larger droplets freeze into complex polycrystals.

The lidar Doppler measurements show that typical fall speeds for the oriented crystals are ≈︁ 0.3 m s−1, with a weak temperature correlation; the corresponding Reynolds number is Re ∼ 10, in agreement with light‐pillar measurements. Coincident Doppler radar observations show no correlation between the specular enhancement and the eddy dissipation rate, indicating that turbulence does not control crystal orientation in these clouds. Copyright © 2010 Royal Meteorological Society
A new algorithm for the downscaling of cloud fields
Authors: Venema Victor , Garc Sebastián Gimeno , Simmer Clemens
Published: January 2010

We present a novel algorithm for the downscaling of three‐dimensional cloud fields. The goal of the algorithm is to add realistic subscale variability to a coarse field taking the resolved variability into account. The method is tested by coarse graining high‐resolution sparse cumulus and broken stratocumulus clouds in the horizontal plane, downscaling these coarse fields back to the high resolution and comparing the radiative and microphysical properties of these downscaled fields with the original high‐resolution fields. The resolutions of the cumulus and stratocumulus clouds used for this purpose are increased by a factor of four and ten, respectively. The downscaling decreases the errors in the flux transmittance and reflectance of the cumulus and stratocumulus cloud fields by at least a factor of ten and three, respectively, compared to utilising the coarse cloud fields. A novel aspect of our algorithm is the fact that it constrains the high‐resolution fields of cloud liquid water content as well as the subscale cloud fraction. An alternative version that does not include cloud fraction information is less accurate, but still significantly better than using the coarse fields. The latter downscaling algorithm can also be utilised for the disaggregation of geophysical fields for which fractional coverages are not defined. Furthermore, the downscaling algorithm can be combined with our other algorithms to generate surrogate fields with other constraints, for example, surrogate clouds with a prescribed liquid water content height distribution. Copyright © 2010 Royal Meteorological Society
Fast 802.11 handovers with 802.1X reauthentications
Authors: Marques Rodolphe , Araújo Edgar , Zúquete André
Published: January 2010

Fast handovers of roaming stations (STAs) between access points (APs) require preauthentication or fast reauthentication within new serving APs. The current standards address only over‐the‐DS (Distribution System) preauthentications for 802.1X authentications. However, over‐the‐DS preauthentication is not suitable for fast moving STAs, which may loose their connection with the currently serving AP before performing preauthentications in the neighbouring APs. This paper presents several ways to achieve fast 802.11 handovers while keeping the basic security features of 802.1X authentications. To do so, we designed a fast 802.1X reauthentication protocol. This protocol enables an STA to perform many fast 802.1X reauthentications after an initial, possible slow, 802.1X authentication. The reauthentication protocol requires little from the network environment, namely a new, central Reauthentication Service (RS) (possibly integrated with the local 802.1X Authentication Server). To speed up 802.1X reauthentications within handovers, the reauthentication protocol was piggybacked into 802.11 management frames that are ordinarily used during handovers. This way, we are able to perform 802.1X reauthentications while taking the normal, over‐the‐air 802.11 steps for performing handovers (network probing, authentication, and (re)association). Besides this over‐the‐air approach, we also show how the 802.1X reauthentication protocol can be implemented using an over‐the‐DS approach. A prototype implementation using over‐the‐air 802.1X reauthentication showed that handover delays can be dramatically reduced to 1.5 ms, while an 802.1X fast resume takes more than 150 ms. Copyright © 2010 John Wiley & Sons, Ltd.
Stochastic modeling and prediction for accrual in clinical trials
Authors: Zhang Xiaoxi , Long Qi
Published: January 2010

Patient accrual in clinical trials is a topic of interest for important practical reasons. It has implications in both the initial planning and ongoing monitoring of trials. Slow accrual is of particular concern when it leads to reduced sample size. Although accrual in clinical trials has been studied and its estimation has been proposed and implemented, the existing methods are usually over‐simplified by assuming a constant or piecewise constant accrual rate, and more flexible and realistic methods are needed. In this paper, we discuss a principled framework to monitor and predict trial accrual. We model trial accrual using a non‐homogeneous Poisson process and model the underlying time‐dependent accrual rate using cubic B‐splines. The statistical inference and prediction procedure for the model are studied in a Bayesian paradigm. We conduct simulation studies to investigate the performance of the proposed approach and compare with a constant accrual rate model discussed by Gajewski et al. (Statist. Med. 2008; 27: 2328–2340). With satisfactory results, we illustrate the proposed method using accrual data from a real oncology trial. Our results show that the proposed model is more robust and achieves substantially better performance compared with the existing methods. Copyright © 2010 John Wiley & Sons, Ltd.
Stem Cell Shape Regulates a Chondrogenic Versus Myogenic Fate Through Rac1 and N-Cadherin
Authors: Gao Lin , McBeath Rowena , Chen Christopher S.
Published: January 2010

Human mesenchymal stem cells (hMSCs) are multipotent cells that can differentiate into many cell types. Chondrogenesis is induced in hMSCs cultured as a micromass pellet to mimic cellular condensation during cartilage development, and exposed to transforming growth factor β (TGFβ). Interestingly, TGFβ can also induce hMSC differentiation to smooth-muscle-like cell types, but it remains unclear what directs commitment between these two lineages. Our previous work revealed that cell shape regulates hMSC commitment between osteoblasts and adipocytes through RhoA signaling. Here we show that cell shape also confers a switch between chondrogenic and smooth muscle cell (SMC) fates. Adherent and well-spread hMSCs stimulated with TGFβ3 upregulated SMC genes, whereas cells allowed to attach onto micropatterned substrates, but prevented from spreading and flattening, upregulated chondrogenic genes. Interestingly, cells undergoing SMC differentiation exhibited little change in RhoA, but significantly higher Rac1 activity than chondrogenic cells. Rac1 activation inhibited chondrogenesis and was necessary and sufficient for inducing SMC differentiation. Furthermore, TGFβ3 and Rac1 signaling upregulated N-cadherin, which was required for SMC differentiation. These results demonstrate a chondrogenic-SMC fate decision mediated by cell shape, Rac1, and N-cadherin, and highlight the tight coupling between lineage commitment and the many changes in cell shape, cell-matrix adhesion, and cell-cell adhesion that occur during morphogenesis.
Cytotoxicity and secondary metabolites production in terrestrial Nostoc strains, originating from different climatic/geographic regions and habitats: Is their cytotoxicity environmentally dependent?
Authors: Hrouzek Pavel , Tomek Petr , Lukešová Alena , Urban Jan , Voloshko Ludmila , Pushparaj Benjamin , Ventura Stefano , Lukavský Jaromír , Štys Dalibor , Kopecký Jiří
Published: January 2010

Extensive selection of cyanobacterial strains (82 isolates) belonging to the genus Nostoc, isolated from different climatic regions and habitats, were screened for both their secondary metabolite content and their cytotoxic effects to mammalian cell lines. The overall occurrence of cytotoxicity was found to be 33%, which corresponds with previously published data. However, the frequency differs significantly among strains, which originate from different climatic regions and microsites (particular localities). A large fraction of intensely cytotoxic strains were found among symbiotic strains (60%) and temperate and continental climatic isolates (45%); compared with the less significant incidences in strains originating from cold regions (36%), deserts (14%), and tropical habitats (9%). The cytotoxic strains were not randomly distributed; microsites that clearly had a higher occurrence of cytotoxicity were observed. Apparently, certain natural conditions lead to the selection of cytotoxic strains, resulting in a high cytotoxicity occurrence, and vice versa. Moreover, in strains isolated from a particular microsite, the cytotoxic effects were caused by different compounds. This result supports our hypothesis for the environmental dependence of cytotoxicity. It also contradicts the hypothesis that clonality and lateral gene transfer could be the reason for this phenomenon. Enormous variability in the secondary metabolites was detected within the studied Nostoc extracts. According to their molecular masses, only 26% of these corresponded to any known structures; thus, pointing to the high potential for the use of many terrestrial cyanobacteria in both pharmacology and biotechnology. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Allergy‐related cytokines (IL‐4 and TNF‐α) are induced by Di(2‐ethylhexyl) phthalate and attenuated by plant‐originated glycoprotein (75 kDa) in HMC‐1 cells
Authors: Lee Jin , Oh Phil‐Sun , Lim Kye‐Taek
Published: January 2010

Phthalate esters as plasticizers have been widespread in the environment and may be associated with development of allergic diseases such as asthma and atopic dermatitis. In this study, we demonstrated that the CTB glycoprotein attenuates allergic reactions caused by di(2‐ethylhexyl) phthalate (DEHP) in human mast cells (HMC‐1). This experiment evaluated degranulation of histamine and β‐hexosaminidase as well as activities of protein kinase C (PKC), stress‐activated protein kinase/c‐Jun N‐terminal kinase (SAPK/JNK), activator protein (AP)‐1 and interleukin (IL)‐4 and tumor necrosis factor (TNF)‐α using immunoblotting and reverse transcription‐polymerase chain reaction (RT‐PCR). Our results revealed that the CTB glycoprotein in the presence of DEHP inhibits degranulation of mast cell, translocation of PKC from cytosol to membrane, and phosphorylation of SAPK/JNK in HMC ‐1 cells. We also found that the CTB glycoprotein (100 μg mL−1) has suppressive effects on transcriptional activation of AP‐1, and on the expression of IL‐4 and TNF‐α in DEHP‐treated HMC‐1 cells. We suggest that the CTB glycoprotein inhibits degranulation of mast cells and expressions of cytokines in HMC‐1 cells. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Dynamic rheology, mechanical performance, shrinkage, and morphology of chemically coupled talc‐filled polypropylene
Authors: Jahani Yousef
Published: January 2010

The oscillatory shear rheological properties, mechanical performance, shrinkage, and morphology of polypropylene (PP)‐talc composites chemically coupled by maleic‐anhydride‐grafted polypropylene (MAPP) were studied. The samples were prepared in a co‐rotating L/D = 40, 25 mm twin‐screw extruder. Tensile tests carried out on injection‐molded samples showed a reinforcing effect of talc up to 20 wt% on PP. Upon using MAPP, the mechanical performance of PP‐30% talc showed a maximum of about 10% increase in tensile strength at 1.5 wt% of MAPP. A Newtonian plateau (η0) at the terminal zone was observed for the complex viscosity curve of pure PP and PP‐talc composites plotted against frequency up to 30 wt%. Upon increasing the talc content to 40 and 50 wt%, the complex viscosity at very low shear rates sharply increased and showed yield behavior that might be due to the formation of a network of filler agglomerates in the melt. Analysis of viscosity behavior in the power‐law region revealed that the flow behavior index‐n‐decreased from 0.45 for 10 wt% of talc down to about 0.4 for 40 wt% of talc. Upon increasing the talc content to 50 wt%, n decreased to a value even lower than that of the neat PP resin. The frequency of the crossover point represents molecular mobility and relaxation‐time behavior. The crossover frequency of the composites was nearly constant up to 30 wt% of talc and decreased at higher filler loadings. The optimum amount of coupling agent could be correlated with the minimum point in crossover frequency and crossover modulus. The shrinkage behavior of the composites with and without MAPP resin was studied and correlated with the rheological properties. J. VINYL ADDIT. TECHNOL., 2010. © 2010 Society of Plastics Engineers
Preparation and characterization of polyaniline‐DBSNa/Fe2O3 and polyaniline‐DBSNa/CoO nanocomposites using surfactive dopant sodium dodecylbenzenesulfonate (DBSNa)
Authors: Eisazadeh Hossein , Khorshidi Hamid Reza
Published: January 2010

Nanocomposites of polyaniline (PAn) containing nanometer‐size Fe2O3 and CoO were synthesized by a chemical method using sodium dodecylbenzenesulfonate (DBSNa) as a surfactant. Characteristics of the products such as morphology, particle size, and conductivity were studied. The results indicated that these properties were dependent on the surfactant and the type and content of metallic oxide used. When the concentration of Fe2O3 and CoO increased from 1 to 5 g/L in the PAn‐DBSNa/Fe2O3 and PAn‐DBSNa/CoO composites, the conductivity decreased from 1.3 × 10−4 to 5.1 × 10−5 and from 1.4 × 10−4 to 5.1 × 10−5 S/cm, respectively, while the particle size increased from 92 to 103 and from 104 to 117 nm, respectively. J. VINYL ADDIT. TECHNOL., 2010. © 2010 Society of Plastics Engineers
Mechanical properties of particulate‐filler/woven‐glass‐fabric‐filled vinyl ester composites
Authors: Yusriah L. , Mariatti M. , Abu Bakar A.
Published: January 2010

Studies of the effect of particulate fillers on specific mechanical properties of vinyl ester epoxy (VE) reinforced with woven glass fiber composites were carried out with different filler types and particulate filler contents (1%, 3%, and 5% by weight). Two types of particulate filler were used, i.e., calcium carbonate (CC) and phenolic hollow microspheres (PHMS). The composites were prepared by using a hand lay‐up and vacuum bagging method. Woven glass fabric composites filled with particulate PHMS were observed to have better specific flexural strength and specific impact strength, as well as lower density, than those filled with particulate CC. Morphological features determined by scanning electron microscope (SEM) proved that the PHMS filler experienced good bonding in the VE matrix, a feature which contributed to the improvement in the properties of the composites. The incorporation of particulate fillers into the composites also influenced the storage modulus with a minimal effect on Tg. J. VINYL ADDIT. TECHNOL., 2010. © 2010 Society of Plastics Engineers
Effect of the combination of a benzophenone‐type ultraviolet absorber with thermal stabilizers on the photodegradation of poly(vinyl chloride)
Authors: Xiang Xiuqin , Chen Shuangjun , Zhang Jun , Chai Ruidan
Published: January 2010

The effect of the combination of a UV absorber (Chimassorb 81) with different types of thermal stabilizers, including an organic calcium complex and an organotin mercaptide, on the photodegradation of poly(vinyl chloride) (PVC) was investigated by color difference measurements, UV–Vis spectroscopy, Fourier‐transform infrared spectroscopy, thermogravimetric (TG) analysis, and viscosity‐average molecular weight determination. Films of PVC containing 0.5 phr of Chimassorb 81, with and without 2 phr of a thermal stabilizer, were prepared by solution casting. Then the accelerated UV weathering of the films was carried out under xenon light with an irradiance of 0.51 W/(m2 · nm) at 65°C. The results showed that both Chimassorb 81 and the mixture of Chimassorb 81 with the organic calcium complex showed good behavior in inhibiting the photodehydrochlorination and photooxidation of PVC. In contrast, the combination of Chimassorb 81 and methyltin mercaptide significantly accelerated initial color development during the final 200 h of exposure because of the UV sensitivity of the organotin. Moreover, when Chimassorb 81 and the methyltin mercaptide were used together to stabilize PVC films, the expected antioxidant effect of the mixture was not observed, in contrast to the behavior found with other stabilized systems, perhaps because the Chimassorb 81 had been depleted by the methyltin mercaptide during the UV irradiation. The TG analysis revealed that ultraviolet irradiation had caused severe destruction of the PVC chains. However, addition of Chimassorb 81 or the combination of Chimassorb 81 with the organic calcium complex effectively prevented the destruction, as was demonstrated by changes in the activation energies for thermal degradation. J. VINYL ADDIT. TECHNOL., 2010. © 2010 Society of Plastics Engineers
From focus groups to peer discourse sessions: The evolution of a method to capture language, meaning, and negotiation
Authors: Manuel Tiffany , Kendall‐Taylor Nathaniel
Published: January 2010

In this article, the authors describe a unique approach to conducting and analyzing focus groups, described as peer discourse analysis. The primary objective of this analysis is to examine the shape and form of the discourses and negotiations that develop organically among peers in discussions of social issues. Peer discourse analysis has both descriptive and prescriptive utility, as it is also used to experiment with frames that might improve people's understanding of complex social problems.
Who says your frames are better than mine? Making the case for strategic framing by using the power of experimental research
Authors: Manuel Tiffany
Published: January 2010

This article details the experimental research on frame effects that provides quantitative evidence that some types of frames have a greater ability to move and affect policy support than others. This method is particularly useful in showing the magnitude by which exposure to alternative ways of thinking about social issues alters the public's policy preferences. This kind of evidence‐based approach to communications is a key to success in providing definitive evidence that strategic framing makes a difference in determining the outcome that matters most to policy advocates: public support.
VDM semantics of programming languages: combinators and monads
Authors: Mosses Peter D.
Published: January 2010

The Vienna Development Method (VDM) was developed in the early 1970s as a variant of denotational semantics. VDM descriptions of programming languages differ from the original Scott–Strachey style by making extensive use of combinators which have a fixed
operational
interpretation. After recalling the main features of denotational semantics and the Scott–Strachey style, we examine the combinators of the VDM specification language, and relate them to monads, which were introduced more than 15 years later. We also suggest that use of further monadic combinators in VDM could be beneficial. Finally, we provide an overview of published VDM semantic descriptions of major programming languages.
A denotational semantics for Handel-C
Authors: Butterfield Andrew
Published: January 2010

We present a denotational semantics for a fully functional subset of the Handel-C hardware compilation language (Celoxica Ltd., Handel-C Language Reference Manual, v3.0, 2002,http://www.celoxica.com), based on the concept of typed assertion traces. We motivate the choice of semantic domains by illustrating the complexities of the behaviour of the language, paying particular attention to the prialt (priority-alternation) construct of Handel-C. We then define the typed assertion traces over an abstract notion of actions, and demonstrate key properties of the key semantic operations on these. The denotational semantics is then given using traces with actions instantiated as state-transformers.
The ND2 subunit is labeled by a photoaffinity analogue of asimicin, a potent complex I inhibitor
Authors: Nakamaru-Ogiso Eiko , Han Hongna , Matsuno-Yagi Akemi , Keinan Ehud , Sinha Subhash C. , Yagi Takao , Ohnishi Tomoko
Published: January 2010

NADH:ubiquinone oxidoreductase (complex I) is the entry enzyme of mitochondrial oxidative phosphorylation. To obtain the structural information on inhibitor/quinone binding sites, we synthesized [3H]benzophenone‐asimicin ([3H]BPA), a photoaffinity analogue of asimicin, which belongs to the acetogenin family known as the most potent complex I inhibitor. We found that [3H]BPA was photo‐crosslinked to ND2, ND1 and ND5 subunits, by the three dimensional separation (blue‐native/doubled SDS–PAGE) of [3H]BPA‐treated bovine heart submitochondrial particles. The cross‐linking was blocked by rotenone. This is the first finding that ND2 was photo‐crosslinked with a potent complex I inhibitor, suggesting its involvement in the inhibitor/quinone‐binding.
Autophagy in plants and phytopathogens
Authors: Yoshimoto Kohki , Takano Yoshitaka , Sakai Yasuyoshi
Published: January 2010

Plants and plant‐associated microorganisms including phytopathogens have to adapt to drastic changes in environmental conditions. Because of their immobility, plants must cope with various types of environmental stresses such as starvation, oxidative stress, drought stress, and invasion by phytopathogens during their differentiation, development, and aging processes. Here we briefly describe the early studies of plant autophagy, summarize recent studies on the molecular functions of ATG genes, and speculate on the role of autophagy in plants and phytopathogens. Autophagy regulates senescence and pathogen‐induced cell death in plants, and autophagy and pexophagy play critical roles in differentiation and the invasion of host cells by phytopathogenic fungi.
Regulation of autophagy by phosphatidylinositol 3‐phosphate
Authors: Burman Chloe , Ktistakis Nicholas T.
Published: January 2010

The simple phosphoinositide phosphatidylinositol 3‐phosphate (PI(3)P) has been known to have important functions in endocytic and phagocytic traffic, and to be required for the autophagic pathway. In all of these settings, PI(3)P appears to create platforms that serve to recruit specific effectors for membrane trafficking events. In autophagy, PI(3)P may form the platform for autophagosome biogenesis.
Paleofire reconstruction for high-elevation forests in the Sierra Nevada, California, with implications for wildfire synchrony and climate variability in the late Holocene
Authors: Hallett Douglas J. , Anderson R. Scott
Published: January 2010

Here, we present two high-resolution records of macroscopic charcoal from high-elevation lake sites in the Sierra Nevada, California, and evaluate the synchroneity of fire response for east- and west-side subalpine forests during the past 9200 yr. Charcoal influx was low between 11,200 and 8000 cal yr BP when vegetation consisted of sparsePinus-dominated forest and montane chaparral shrubs. High charcoal influx after 8000 cal yr BP marks the arrival ofTsuga mertensianaandAbies magnifica, and a higher-than-present treeline that persisted into the mid-Holocene. Coeval decreases in fire episode frequency coincide with neoglacial advances and lower treeline in the Sierra Nevada after 3800 cal yr BP. Independent fire response occurs between 9200 and 5000 cal yr BP, and significant synchrony at 100- to 1000-yr timescales emerges between 5000 cal yr BP and the present, especially during the last 2500 yr. Indistinguishable fire-return interval distributions and synchronous fires show that climatic control of fire became increasingly important during the late Holocene. Fires after 1200 cal yr BP are often synchronous and corroborate with inferred droughts. Holocene fire activity in the high Sierra Nevada is driven by changes in climate linked to insolation and appears to be sensitive to the dynamics of the El Niño–Southern Oscillation.
L'ethnie: les vicissitudes d'un concept
Authors: de Heusch Luc
Published: January 2010

Le mot ethnie a un passé équivoque dans la langue française. Vacher de Lapouge est le premier à l'utiliser en 1896 pour désigner de prétendues «races» distinctes, notion dont la biologie des populations a fait justice. Le terme ne s'appliquait pas seulement aux «primitifs»; il contribua à hérisser des barrières entre les «races» dites inférieures et les «races» dites supérieures. En 1935, G. Montandon, qui se fera l'apôtre d'une certaine conception nazie de l'homme, consacre un livre à «l'ethnie française». Les administrateurs coloniaux utiliseront, quant à eux, le terme ethnie comme substitut de «tribu» ou «peuplade» avec souvent la conviction, fallacieuse, que des caractères anatomiques particuliers entrent dans les particularités du groupe ainsi qualifié. Mais Franz Boas, le fondateur de l'anthropologie culturelle aux États-Unis, réagit avec vigueur. II déclare fermement dès 1932 : « Les résultats des matériaux extensifs amassés au cours des cinquante dernières années ne justifient pas l'hypothèse d'une quelconque relation entre types biologiques et forme de culture » (Boas, 1932, cité par Condominas, 1980, p. 89). Cette conviction sera largement partagée par la majorité des ethnologues, sauf en Allemagne. Dérivé du grecethnos(peuple) le terme ethnie entre dans le vocabulaire scientifique avec une connotation exclusivement culturelle. Mais ce concept se voit attaqué depuis une dizaine d'années sur le terrain même de l'ethnologie où il s'est developpé. Quelques chercheurs français s'ingénient à démontrer que leurs prédécesseurs, travaillant principalement en Afrique, ont eu le tort de donner consistance à de fausses entités.
Is Sicily the future of Russia? Private protection and the rise of the Russian Mafia
Authors: Varese Federico
Published: January 2010

It is difficult to discuss a phenomenon when one does not know precisely what it is. This problem is particularly vexing in the case of the Mafia. It has been argued that ‘the need for a definition [of the Mafia] is crucial; not just for any definition with some degree of contingent empirical plausibility, but for a definition with some analytical clout’ (1). The word ‘Mafia’ itself has travelled far to distant lands, such as the former Soviet Union. For instance, according to Arkadii Vaksberg, Russian journalist and author of The Russian Mafia, the Mafia is ‘the entire soviet power-system, all its ideological, political, economical and administrative manifestations’ (2). In an article published in a magazine for British executives dealing with Russia, the label Mafiosi is used to lump together bureaucrats, smugglers from the Caucasus, the CPSU nomenklatura accused of embezzling state funds, the late British businessman Robert Maxwell and many others (3).
De Weber à Nietzsche
Authors: Fleischmann Eugène
Published: January 2010

Nous cherchons l'homme qui a pu prononcer publiquement cette phrase, nous voulons retrouver un Max Weber qui n'est pas seulement le spécialiste de problèmes sociologiques ou économiques, mais qui est en même temps aussi le penseur et le guide de la jeunesse intellectuelle. La recherche minutieuse qui s'impose ici n'a été faite que d'une manière tres incomplète (1), sans doute parce que les différentes filiations, afnnités, fréquentations intellectuelles qui pourraient aider à définir la pensée wébérienne apparaissent sous un jour encore plus déconcertant que les recherches concretes du grand sociologue: le caractère encyclopédique de son savoir, là aussi, l'emportait vers un nombre invraisemblable de doctrines et de systèmes. Ce sont ees fils qu'il nous faut dégager à grand-peine des courants de pensée de la deuxième moitié du XIXe siècle, où ses convictions fondamentales situent Weber. On accordera volontiers que cette richesse, ce foisonnement intellectuel — en contraste avec la richesse de sa sociologie proprement dite — ne pouvait guère conduire Weber qu'à une sorte d'éclectisme philosophique. Mais le lecteur ainsi averti se souviendra sans doute que le «désenchantement»idéologique ne diminue en rien l'importance de la riche contribution qu'apportait Weber à la science, à la sociologie.