bluuebunny/crossref_metadata_2025 huggingface dataset:
Modellierung des Einflusses von Wildverbiss auf die Schutzwaldentwicklung an der Rigi-Nordlehne
Authors: Stadelmann Golo , Frehner Monika , Baltensweiler Andri , Bugmann Harald
Published: October 2011

Modelling the impact of ungulate browsing on the development of the protective forests of the Rigi-Nordlehne

Forests on the northern slopes of the Rigi Mountain in central Switzerland (“Rigi-Nordlehne”) have a key protective function against rockfall, erosion, landslides, flooding and debris flows. Forest management endeavours to guarantee that these forests can maintain their role in the long term. Thus multi-story canopies are favored, being resistant and resilient to natural disturbances such as windthrow. In addition, the mixture of tree species should conform to the guidelines of the national project “Sustainability and success monitoring in protection forests” (NaiS). However, at the present time an imbalance in tree species is evident in the regeneration layer, due to the considerable impact of browsing by wild ungulate populations in these beech and fir forests. To predict future mixtures of tree species, the spatially explicit model of forest development Rigfor was developed and applied to simulate and compare two scenarios of forest dynamics. The scenario “current browsing” suggests that silver fir cannot regenerate and that regeneration of maple and beech is greatly hindered. In the scenario “reduced browsing”, however, a species mixture conforming to the national guidelines can be achieved in the regeneration layer. The simulations show that the amount of beech timber decreases whichever the scenario, while for the larger fir trees in diameter classes above 35 cm no changes are to be expected in the coming decades. However, from 2082 onwards a continuing high browsing rate would lead to the elimination of nearly all silver fir trees at the pole stage and in the long run silver fir may be completely eradicated from these stands. We conclude that under a dense canopy of old trees, silver fir and beech can be regenerated if ungulate browsing is considerably reduced. Spruce regeneration however requires more light and this is not often found on the northern slopes of the Rigi Mountain. Opening up the canopy to foster regeneration of the desired mixture of species is a key measure in order to maintain the long-term protective function of these forests. This will only be possible, however, if the current high browsing intensity can be reduced.
Modeling Effects of Climate Change and Fire Management on Western White Pine (Pinus monticola) in the Northern Rocky Mountains, USA
Authors: Loehman Rachel A. , Clark Jason A. , Keane Robert E.
Published: October 2011

Climate change is projected to profoundly influence vegetation patterns and community compositions, either directly through increased species mortality and shifts in species distributions or indirectly through disturbance dynamics such as increased wildfire activity and extent, shifting fire regimes, and pathogenesis. Mountainous landscapes have been shown to be particularly sensitive to climate changes and are likely to experience significant impacts under predicted future climate regimes. Western white pine (Pinus monticola), a five-needle pine species that forms the most diverse of the white pine forest cover types in the western United States, is vulnerable to an interacting suite of threats that includes climate change, fire suppression, white pine blister rust (Cronartium ribicola), and mountain pine beetles (Dendroctonus ponderosae) that have already caused major changes in species distribution and abundance. We used the mechanistic simulation model FireBGCv2 to simulate effects of climate change and fire management on western white pines in a mountainous watershed in Glacier National Park, Montana, USA. Our results suggest that warming temperatures favor increased abundance of western white pine over existing climax and shade tolerant species in the study area, mainly because warmer conditions potentiate fire dynamics, including increased wildfire frequency and extent, which facilitates regeneration. Suppression of wildfires reduced the area dominated by western white pine, but fire suppression was less effective at limiting burned area extent and fire frequency in a warmer and drier climate. Wildfires created canopy gaps that allowed for western white pine regeneration at a high enough rate to escape local extirpation from white pine blister rust. Western white pine appears to be a resilient species even under fairly extreme warming trajectories and shifting fire regimes, and may provide a hedge against vegetation community shifts away from forest types and toward grass and shrublands.
Design of Highly Sensitive C2H5OH Sensors Using Self-Assembled ZnO Nanostructures
Authors: Kim Kang-Min , Kim Hae-Ryong , Choi Kwon-Il , Kim Hyo-Joong , Lee Jong-Heun
Published: October 2011

Various ZnO nanostructures such as porous nanorods and two hierarchical structures consisting of porous nanosheets or crystalline nanorods were prepared by the reaction of mixtures of oleic-acid-dissolved ethanol solutions and aqueous dissolved Zn-precursor solutions in the presence of NaOH. All three ZnO nanostructures showed sensitive and selective detection of C2H5OH. In particular, ultra-high responses (Ra/Rg = ~1,200, Ra: resistance in air, Rg: resistance in gas) to 100 ppm C2H5OH was attained using porous nanorods and hierarchical structures assembled from porous nanosheets, which is one of the highest values reported in the literature. The gas response and linearity of gas sensors were discussed in relation to the size, surface area, and porosity of the nanostructures.
Médecine générale, psychanalyse et psychiatrie
Authors: Kornobis Jean-Paul
Published: October 2011

Résumé Cette intervention vise à démontrer que la psychanalyse, depuis Freud et Lacan, peut permettre aux médecins généralistes une analyse plus pertinente des actes de langage et des idéologies à l’origine des symptômes. Parce qu’elle n’est « pas toute » psychothérapeutique, la psychanalyse permet, en effet, de mieux cerner les enjeux d’une politique de santé mentale qui tente d’adapter les soins aux facteurs de l’économie moderne. Nous chercherons à expliquer comment, pour faire face aux exigences des « usagers de la santé », les médecins généralistes sont poussés à ignorer les problématiques induites par la notion d’inconscient freudien, au profit d’une modélisation neurobiologique plus facilement évaluable et quantifiable. Enfin, nous démontrerons que le burn-out, version moderne de la « livre de chair » shakespearienne, est souvent le prix à payer pour le médecin lorsqu’il évacue le « réel » de l’inconscient freudien au profit d’un « symbolique » noué à un « imaginaire » plus facilement maîtrisable.
Quelques propos sur le pouvoir en psychothérapie et en psychanalyse
Authors: Radiszcz Esteban
Published: October 2011

Résumé Sous une approche politique du problème des psychothérapies, on examine l’ Evidence-based Psychotherapy qui, née dans les vingt dernières années, semble représenter une forme de gouvernementalité contemporaine des vivants. Néanmoins, un tel examen ne saurait se faire sans se trouver confronté à la vive et difficile question du pouvoir en psychanalyse.
On n'y voit rien ! Sur la visibilité des suicides et l'audibilité des symptômes au travail
Authors: Fleury Emmanuel
Published: October 2011

Résumé Les passages à l’acte suicidaires au travail ou sur le lieu du travail ne se distinguent pas des passages à l’acte réalisés ailleurs. Leur fulgurance brutale surprend l’entourage, collègues, amis et famille. Pas toujours annoncés, parfois si discrets que dans les grandes entreprises ils peuvent être méconnus. Souvent tus par la suite, leur manque de visibilité peut expliquer notre méconnaissance de la question. Serait-ce que l’on arrive toujours un peu trop tard avec le suicide ? À l’inverse du symptôme qui préviendrait ? Il est possible que d’autres choses encore opposent acte suicidaire et symptôme. Ce qui inciterait à penser qu’il ne faudrait pas chercher la signification du malaise dans le suicide lui-même mais autour de lui.
Le discours capitaliste : « cinquième discours » ? Anticipation du « discours pst », ou peste
Authors: Braunstein Néstor A.
Published: October 2011

Résumé Des discours, il n’y en a que quatre : à ce sujet, Lacan était taxatif. Quelle place, donc, peut-on accorder au syntagme « discours du capitaliste » (4 novembre1968-3 novembre 1973) et à sa bizarre formulation ? Quelle est la place du discours ps, pst, peste (post ?), énoncé à Milan en 1972 ?
Dire que non... Portrait de Bartleby en révolutionnaire
Authors: Ego Sylvette
Published: October 2011

Résumé Le personnage de Bartleby suscite engouements et controverses mais fait l’unanimité sur son caractère emblématique. Les lectures qu’en font Gilles Deleuze et Slavoj Zizek le situent comme porteur d’une position authentiquement révolutionnaire. Bartleby propose-t-il vraiment une position permettant de sortir de l’alternative entre servitude volontaire et domination plus ou moins cynique ? Entre vaine révolte et résignation ?
Comparative Study of Cyanobacterial andE. coliRNA Polymerases: Misincorporation, Abortive Transcription, and Dependence on Divalent Cations
Authors: Imashimizu Masahiko , Tanaka Kan , Shimamoto Nobuo
Published: October 2011

If Mg2+ion is replaced by Mn2+ion, RNA polymerase tends to misincorporate noncognate nucleotide, which is thought to be one of the reasons for the toxicity of Mn2+ion. Therefore, most cells have Mn2+ion at low intracellular concentrations, but cyanobacteria need the ion at a millimolar concentration to maintain photosynthetic machinery. To analyse the mechanism for resistance against the abundant Mn2+ion, we compared the properties of cyanobacterial andE. coliRNA polymerases. The cyanobacterial enzyme showed a lower level of abortive transcription and less misincorporation than theE. colienzyme. Moreover, the cyanobacterial enzyme showed a slower rate of the whole elongation by an order of magnitude, paused more frequently, and cleaved its transcript faster in the absence of NTPs. In conclusion, cyanobacterial RNA polymerase maintains the fidelity of transcription against Mn2+ion by deliberate incorporation of a nucleotide at the cost of the elongation rate. The cyanobacterial and theE. colienzymes showed different sensitivities to Mg2+ion, and the physiological role of the difference is also discussed.
Applying grounded theory to data collected through participatory research on African Independent Churches’ liturgical rituals: A comparative study
Authors: Müller Bethel A. , Wepener Cas J.
Published: October 2011

This article reported on two research projects, the first conducted in the early 1990s and the second, a project currently in progress. In essence, the article was an attempt to compare the theology of African Independent Churches in the two respective periods by making use of a grounded theory approach to their worship services. Significant similarities and differences were identified and reported on.
Large scale changes in 20th century black carbon deposition to Antarctica
Authors: Bisiaux M. M. , Edwards R. , McConnell J. R. , Curran M. A. J. , Van Ommen T. D. , Smith A. M. , Neumann T. A. , Pasteris D. R. , Penner J. E. , Taylor K.
Published: October 2011

Abstract. Refractory black carbon aerosols (rBC) emitted by biomass burning (fires) and fossil fuel combustion, affect global climate and atmospheric chemistry. In the Southern Hemisphere (SH), rBC is transported in the atmosphere from low latitudes to Antarctica and deposited to the polar ice sheet preserving a history of emissions and atmospheric transport. Here, we present two high-resolution Antarctic rBC ice core records drilled from the West Antarctic Ice Sheet divide and Law Dome on the periphery of the East Antarctic ice sheet. Separated by ~3500 km, the records span calendar years 1850–2001 and reflect the rBC distribution over the Indian and Pacific ocean sectors of the Southern Ocean. Highly correlated over the past 60 yr, the records show that coherent large-scale changes in SH rBC occurred at decadal to inter-annual time scales, notably in ENSO-like periodicities. Decadal trends in the records are similar to inventories of SH rBC emissions from grass fires and biofuels. The combined records suggest a large-scale reduction in rBC from 1950 to 1990 over the remote Southern Hemisphere.
Initial investigation of the wavelength dependence of optical properties measured with a new multi-pass aerosol extinction differential optical absorption spectrometer (AE-DOAS)
Authors: Chartier R. T. , Greenslade M. E.
Published: October 2011

Abstract. Atmospheric aerosols directly affect climate by scattering and absorbing radiation. The magnitude of the impact is dependent upon the wavelength of light, but is often estimated near 550 nm. When light scattering and absorption by aerosols is approximated, the wavelength dependence of the refractive index for specific components is lost. As a result, climate models would have inherent uncertainties for aerosol contributions to radiative forcing when considering the entire solar spectrum. An aerosol extinction differential optical absorption spectrometer has been developed to directly measure aerosol extinction at mid-ultraviolet to near infrared wavelengths. The instrument consists of a spectrometer coupled to a closed White-type multi-pass gas cell with an adjustable path length of up to approximately 20 m. Laboratory measurements of various gases are compared with known absorption cross sections. Additionally, the extinction of monodisperse samples of polystyrene latex spheres are measured and compared to Mie theory generated with refractive index values from the literature to validate the new instrument. The polystyrene experiments also emphasize the ability of the new instrument to retrieve the wavelength dependent refractive index, especially in the ultraviolet wavelength regions where variability is expected. The spectrometer will be a significant advancement for determining wavelength dependent complex refractive indices in future laboratory studies as well as provide the ability to monitor ambient aerosol light extinction.
Predicting and partitioning ozone fluxes to maize crops from sowing to harvest: the Surfatm-O3 model
Authors: Stella P. , Personne E. , Loubet B. , Lamaud E. , Ceschia E. , Béziat P. , Bonnefond J. M. , Irvine M. , Keravec P. , Mascher N. , Cellier P.
Published: October 2011

Abstract. Terrestrial ecosystems represent a major sink for ozone (O3) and also a critical control of tropospheric O3 budget. However, due to its deleterious effects, plant functioning is affected by the ozone absorbed. It is thus necessary to both predict total ozone deposition to ecosystems and partition the fluxes in stomatal and non-stomatal pathways. The Surfatm-O3 model was developed to predict ozone deposition to agroecosystems from sowing to harvest, taking into account each deposition pathways during bare soil, growth, maturity, and senescence periods. An additional sink was added during senescence: stomatal deposition for yellow leaves, not able to photosynthesise but transpiring. The model was confronted to measurements performed over three maize crops in different regions of France. Modelled and measured fluxes agreed well for one dataset for any phenological stage, with only 4% difference over the whole cropping season. A larger discrepancy was found for the two other sites, 15% and 18% over the entire study period, especially during bare soil, early growth and senescence. This was attributed to site-specific soil resistance to ozone and possible chemical reactions between ozone and volatile organic compounds emitted during late senescence. Considering both night-time and daytime conditions, non-stomatal deposition was the major ozone sink, from 100% during bare soil period to 70–80% on average during maturity. However, considering only daytime conditions, especially under optimal climatic conditions for plant functioning, stomatal flux could represent 75% of total ozone flux. This model could improve estimates of crop yield losses and projections of tropospheric ozone budget.
Assessment of weather-related risk on chestnut productivity
Authors: Pereira M. G. , Caramelo L. , Gouveia C. , Gomes-Laranjo J. , Magalhães M.
Published: October 2011

Abstract. Due to its economic and nutritional value, the world production of chestnuts is increasing as new stands are being planted in various regions of the world. This work focuses on the relation between weather and annual chestnut production to model the role of weather, to assess the impacts of climate change and to identify appropriate locations for new groves. The exploratory analysis of chestnut production time series and the striking increase of production area have motivated the use for chestnut productivity. A large set of meteorological variables and remote sensing indices were computed and their role on chestnut productivity evaluated with composite and correlation analyses. These results allow for the identification of the variables cluster with a high correlation and impact on chestnut production. Then, different selection methods were used to develop multiple regression models able to explain a considerable fraction of productivity variance: (i) a simulation model (R2-value = 87%) based on the winter and summer temperature and on spring and summer precipitation variables; and, (ii) a model to predict yearly chestnut productivity (R2-value of 63%) with five months in advance, combining meteorological variables and NDVI. Goodness of fit statistic, cross validation and residual analysis demonstrate the model's quality, usefulness and consistency of obtained results.
An improved semi-empirical model for the densification of Antarctic firn
Authors: Ligtenberg S. R. M. , Helsen M. M. , van den Broeke M. R.
Published: October 2011

Abstract. A firn densification model is presented that simulates steady-state Antarctic firn density profiles, as well as the temporal evolution of firn density and surface height. The model uses an improved firn densification expression that is tuned to fit depth-density observations. Liquid water processes (meltwater percolation, retention and refreezing) are also included. Two applications are presented. First, the steady-state model version is used to simulate the strong spatial variability in firn layer thickness across the Antarctic ice sheet. Second, the time-dependent model is run for 3 Antarctic locations with different climate conditions. Surface height changes are caused by a combination of accumulation, melting and firn densification processes. On all 3 locations, an upward trend of the surface during autumn, winter and spring is present, while during summer there is a more rapid lowering of the surface. Accumulation and (if present) melt introduce large inter-annual variability in surface height trends, possibly hiding ice dynamical thickening and thinning.
Tough Bio‐Based Elastomer Nanocomposites with High Performance for Engineering Applications
Authors: Wei Tao , Lei Lijuan , Kang Hailan , Qiao Bo , Wang Zhao , Zhang Liqun , Coates Phil , Hua Kuo‐Chih , Kulig Joseph
Published: October 2011

Biomass feedstock is a viable alternative to finite fossil fuel resources to provide many of the same—plus others that petrochemicals cannot—chemical building blocks required to fabricate durable and high‐performance materials. We demonstrate here for the first time a new generation of synthesized elastomers, namely bio‐based engineering elastomers (BEE). These are of particular significance because they are synthesized from monomers derived from biomass, by routes which are suitable for large scale production, and they exhibit thermo‐mechanical properties at least equivalent to current commercial petrochemical‐derived elastomers. Bio‐based monomers in large scale production, such as sebacic acid, itaconic acid, succinate acid, 1,3‐propanediol, and 1,4 butanediol are chosen to generate the first synthetic BEE matrix through melting polycondensation—a comparatively simple reaction scheme offering good control and the potential for low cost, large‐scale production. A novel linear BEE, an almost non‐crystalline copolyester elastomer with low glass transition temperature (Tg) containing double bonds is designed and synthesized using multiple monomers (to help suppress crystallization). Silica nanoparticles are then introduced into the BEE matrix to achieve significant strengthening and improved environmental stability. Chemical crosslinks formed by peroxide and the pendant double bonds in the copolyester macromolecules endow the BEE with both the necessary high elasticity and required environmental stability. The BEE nanocomposites obtained exhibit excellent thermomechanical properties, such as an ultimate tensile strength of 20 MPa.
Nanofunctionalized Superhydrophobic Antifouling Coatings for Environmental Sensor Applications—Advancing Deployment with Answers from Nature
Authors: Chapman James , Regan Fiona
Published: October 2011

In this work, a novel preparation for superhydrophobic nanofunctionalized silver and gold, copper‐coated substrates as potential antifouling coatings for environmental monitoring devices are fabricated. The superhydrophobic coating is topographically similar to the design of the Lotus leaf (Nelumbo necifera) and was synthesized by creating an electroless galvanic reaction between copper and the metal salt. In doing so, a nano‐ and micro‐topographical structure was created on the surface of a copper substrate which can be rendered superhydrophobic through the addition of a self‐assembled monolayer (SAM) of CF3(CF2)7CH2CH2SH.

The work investigates whether the hydrophobicity of such materials affects micro‐organism attachment and subsequent biofouling. The materials are deployed in a marine environment in Dublin, Ireland for a 6 week study to determine the overall antifouling capacity. The materials are analyzed for biomass, slime (glycocalyx) production and more specifically protein and carbohydrate adsorption all of which are attributed to the inherent makeup of biofilm and exopolymeric substances (EPS) which are secreted by micro‐organisms during the biofouling process. This work highlights the dominance of combinational antifouling approaches rather than single tactics for such a complex problem and one that plagues multiple research areas. This novel approach in developing a new antifouling material for sensors, and indeed, any aquatic platform has shown excellent results throughout.
Drug‐Coated Angioplasty Balloon Catheters: Coating Compositions and Methods
Authors: Berg Madeleine Caroline , Kolodziej Herbert , Cremers Bodo , Gershony Gary , Speck Ulrich
Published: October 2011

Flow‐limiting stenosis or total occlusion of coronary, cerebral, or peripheral arteries is very common. Minimally invasive treatment with balloon catheters optionally combined with stent implantation immediately relieves symptoms. However, renarrowing of dilated vessel segments due to excessive scar formation frequently reverses the initial success observed soon after treatment. Coating of balloons with antiproliferative drugs is a promising approach to overcome this problem. The coating of angioplasty balloon membranes is a challenging task. It must ensure homogeneous distribution of the antiproliferative agent and adherence to the balloon membrane during handling and on the way to the treatment site in a distant artery, where the agent should be immediately released and transferred to the vessel wall when the balloon is inflated. In vitro and in vivo testing methods are described. The impact of different kinds of balloons, drugs, additives, and coating methods has been investigated, and the results of representative examples including clinically tested products are presented and discussed.
Harnessing Interfacial Phenomena to Program the Release Properties of Hollow Microcapsules
Authors: Lee Myung Han , Hribar Kolin C. , Brugarolas Teresa , Kamat Neha P. , Burdick Jason A. , Lee Daeyeon
Published: October 2011

The generation of near‐infrared (NIR)‐sensitive microcapsules is presented and it is demonstrated that the release properties of these microcapsules can be tailored by controlling their morphology. A biocompatible polymer, poly(DL‐lactic‐co‐glycolic)acid (PLGA) is used to form hollow microcapsules from monodisperse water‐in‐oil‐in‐water (W/O/W) double emulsions. Both the composition of PLGA and the oil phase of W/O/W double emulsions significantly affect the morphology of the subsequently formed microcapsules. PLGA microcapsules with vastly different morphologies, from spherical to “snowman‐like” capsules, are obtained due to changes in the solvent quality of the oil phase during solvent removal. The adhesiveness of the PLGA‐laden interface plays a critical role in the formation of snowman‐like microcapsules. NIR‐sensitive PLGA microcapsules are designed to have responsive properties by incorporating Au nanorods into the microcapsule shell, which enables the triggered release of encapsulated materials. The effect of capsule morphology on the NIR responsiveness and release properties of PLGA microcapsules is demonstrated.
Growth and the development of sexual size dimorphism in lorises and galagos
Authors: O'Mara M. Teague , Gordon Adam D. , Catlett Kierstin K. , Terranova Carl J. , Schwartz Gary T.
Published: October 2011

Three fundamental ontogenetic pathways lead to the development of size differences between males and females. Males and females may grow at the same rate for different durations (bimaturism), grow for the same duration at different rates, or grow at a mix of rate and duration differences. While patterns of growth and the development of adult body size are well established for many haplorhines, the extent to which rate and duration differences affect strepsirrhine growth trajectories remains unclear. Here, we present iterative piecewise regression models that describe the ontogeny of adult body mass for males and females of five lorisoid species (i.e., lorises and galagos) from the Duke Lemur Center. We test the hypotheses that, like most haplorhines, sexual size dimorphism (SSD) is a result of bimaturism, and males and females of monomorphic species grow at the same rate for a similar duration. We confirm that the galagos in this sample (Galago moholi and Otolemur garnettii) show significant SSD that is achieved through bimaturism. Unlike monomorphic lemurids, the lorises in this sample show a diversity of ontogenetic patterns. Loris tardigradus does follow a lemur‐like trajectory to monomorphism but Nycticebuscoucang and Nycticebus pygmaeus achieve larger adult female body sizes through a mixture of rate and duration differences. We show that contrary to previous assumptions, there are patterns of both similarity and difference in growth trajectories of comparably sized lorises and galagos. Furthermore, when ontogenetic profiles of lorisoid and lemurid growth are compared, it is evident that lorisoids grow faster for a shorter period of time. Am J Phys Anthropol, 2012. © 2011 Wiley Periodicals, Inc.
An efficient and recyclable silica‐supported carbene–Cu(II) catalyst for the oxidative coupling reaction of terminal alkynes with H‐phosphonates under base‐free reaction conditions
Authors: Liu Ping , Yang Jin , Li Pinhua , Wang Lei
Published: October 2011

The oxidative coupling reactions of terminal alkynes with H‐phosphonates were explored using SiO2−NHC−Cu(II) (5.0 mol%) as catalyst at room temperature under base‐free reaction conditions. The reactions of a variety of terminal alkynes with H‐phosphonates generated the corresponding alkynylphosphonate products in good to excellent yields. In addition, SiO2−NHC−Cu(II) could be recovered and recycled for six consecutive trials without significant loss of its reactivity. Copyright © 2011 John Wiley & Sons, Ltd.
Reactive electrospinning of poly(vinyl alcohol) nanofibers
Authors: Yuan Jiang , Mo Hong , Wang Miao , Li Li , Zhang Jun , Shen Jian
Published: October 2011

We aim to couple the electrospinning in‐line with solution chemistry to fabricate novel crosslinked polymer nanofibers. Poly(vinyl alcohol) (PVA) was used as a model polymer due to its high amount of hydroxyl groups. To obtain ideal parameters for electrospinning, pure PVA was explored primarily. To gain crosslinked fibers, PVA was first crosslinked partially with glutaraldehyde (GA) followed by transferring this precursor to a long hot tube which was used as reactor and then electrospun right before gelation. The preheating time and tube‐passing time were determined with viscometer and rheometer. The reactive as‐spun fibers could maintain their original morphology after water immersion due to their high crosslinking degree. The thermal stability and mechanical property of reactive as‐spun fibers were improved drastically compared with pure and GA vapor crosslinked PVA fibers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Thermophysical properties of foliated graphite/nickel reinforced polyvinyl chloride nanocomposites
Authors: Al‐Ghamdi A. A. , Al‐Salamy Falleh , Al‐Hartomy Omar A. , Al‐Ghamdi Attieh A. , Abdel Daiem A. M. , El‐Tantawy Farid
Published: October 2011

A novel, polymer‐based foliated graphite/nickel nanocomposites with high thermal conductivity, mechanical properties, and low dielectric constant was developed. The network structure of polyvinyl chloride (PVC) reinforced foliate graphite and nickel nanoparticles (GN) were tested in terms of X‐ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive x‐ray analysis (EDX), and thermal‐gravimetric analyses (TGA). Thermogravimetric analysis revealed a large improvement in the thermal stability of PVC/GN nanocomposites. Thermal conductivity and diffusivity of the composites increased with increasing GN content and temperature. The obtained experimental thermal conductivity result are compared with the existing theoretical models. The measured values of thermal conductivity were in excellent agreement with those calculated from the Agari model. In addition, specific heat, coefficient of thermal expansion (TEC), micro porosity, and crosslinking density (CLD) of composites were investigated. The mechanical properties such as tensile strength, tensile modulus, hardness, and elongation at break of the nanocomposites were improved with inclusion GN which is proportional to GN content. Finally, the dielectric properties of PVC/GN nanocomposites as a function of frequency have been investigated in details. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Nonisothermal crystallization and melting behavior of PP/nanoclay/CaCO3 ternary nanocomposite
Authors: Zare Yasser , Garmabi Hamid
Published: October 2011

Nonisothermal crystallization and melting behavior of PP/nanoclay/CaCO3 ternary nanocomposite were investigated using different melt flow index (MFI) of PP, nanoclay and CaCO3 contents. The rate of crystallization was also studied using relative crystallinity as a function of temperature and time. The results show that the increase of MFI of PP and CaCO3 content in the prepared ternary nanocomposite shift the crystallization curve of PP to the higher temperature. However, increasing the content of nanoclay from 2 wt % to 6 wt % decreases the crystallization temperature possibly due to the restriction of molecular chain mobility. Further analysis of nonisothermal crystallization was carried out based on Avrami equation which the crystallization kinetic of prepared nanocomposite was evaluated. Except the significant variation in the heat of melting, the influence of these parameters on the melting behavior was much less than the crystallization process. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Thermal degradation analysis of the isocyanate polyhedral oligomeric silsequioxanes (POSS)/sulfone epoxy nanocomposite
Authors: Chiu Yie‐Chan , Tsai Hsieh‐Chih , Imae Toyoko
Published: October 2011

The sulfone epoxy (SEP)/polyhedral oligomeric silsesquioxane (POSS) nanocomposite contains bulky POSS side chains was studied in this research. Its glass transition temperature (Tg) decreases with the bulky POSS content, indicating that the bulky POSS side chains could not only generate the oligomers but also interrupt the network architectures of SEP. Homogeneous and uniform dispersion of POSS in SEP matrix can be obtained through the carbamate/oxazolidon covalent linkage, which is evidenced by scanning electron microscopy. The increasing concentration of POSS into SEP exhibits an increase of char yield in the nanocomposites, indicating that the POSS segments provide the antithermal‐oxidation effect for SEP/POSS, thereby inhibiting thermal degradation under open air at high temperatures. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Elaborating on Efficient Anti‐Proliferation Agents of Cancer Cells and Anti‐Inflammatory‐Based N‐Bisphosphonic Acids
Authors: Abdou Wafaa M. , Khidre Rizk E. , Kamel Azza A.
Published: October 2011

Methylenebisphosponic acid tetraethyl ester (1) was added to 2‐azido‐7a–e and 2‐chloroquinoline‐3‐chalcones 10a–e in boiling sodium ethanolate solution to give, via Michael addition, tetrazolo[1,5‐a]quinoline‐8a–d, 13a and 2‐chloroquinoline‐based bisphosphonates 11a–d, 14a in E‐configuration. Further acid hydrolysis afforded the respective BP‐acid analogues E‐9a–d, 12a–d, 13b, and 14b in excellent yields. Anti‐tumor activity screening for the new BP‐acids at a dose of 10 µM utilizing 44 different human tumor cell lines representing breast, ovary, prostate, lung, and CNS cancer as well as leukemia and melanoma was carried out. Eight of ten tested compounds exhibited remarkable anti‐tumor activity against breast and prostate cancer, and a promising anti‐tumor sensitivity toward ovarian cancer and melanoma. Conversely, there was only scattered activity against leukemia and no noticeable action of these BP‐acids on CNS or lung cancer. Based on the prediction results (PASS program), anti‐inflammatory activity of the new acids was also determined in vivo, by the acute carrageenin induced paw edema in rats. Many of these compounds showed anti‐inflammatory properties at a dose of 50 mg/kg body weight.
Determination of phenformin hydrochloride using molecular imprinting technology coupled with flow‐injection chemiluminescence
Authors: Liu Zhenbo , Jia Fengyan , Wang Wenwen , Wang Cuixia , Liu Yongming
Published: October 2011

A novel method was developed using molecular imprinting technology (MIT) coupled with flow‐injection chemiluminescence (FI‐CL) for highly sensitive detection of phenformin hydrochloride (PH). The phenformin imprinted polymer was synthesized with methacrylic acid (MAA) as a functional monomer and ethylene glycol dimethacrylate (EGDMA) as a cross‐linker. Newly synthesized molecularly imprinted polymer (MIP) particles were packed into a column as a selective recognition element for determination of PH. A CL method for the determination of PH was developed based on the CL reaction of PH with N‐bromosuccinimide sensitized by eosin Y in basic media. The optimization of detection conditions was investigated. The CL intensity responded linearly to the concentration of PH in the range 0.09–2.0 µg/mL, with a correlation coefficient of 0.9920. The detection limit was 0.031 µg/mL. The relative standard deviation for the determination of 1.0 µg/mL PH solution was 1.0% (n = 11). The method was applied to the determination of PH in urine samples, with satisfactory results. Copyright © 2011 John Wiley & Sons, Ltd.
Viscoelastic properties and nanoscale structures of composite oligopeptide‐polysaccharide hydrogels
Authors: Hyland Laura L. , Taraban Marc B. , Feng Yue , Hammouda Boualem , Yu Y. Bruce
Published: October 2011

Biocompatible and biodegradable peptide hydrogels are drawing increasing attention as prospective materials for human soft tissue repair and replacement. To improve the rather unfavorable mechanical properties of our pure peptide hydrogels, in this work we examined the possibility of creating a double hydrogel network. This network was created by means of the coassembly of mutually attractive, but self‐repulsive oligopeptides within an already‐existing fibrous network formed by the charged, biocompatible polysaccharides chitosan, alginate, and chondroitin. Using dynamic oscillatory rheology experiments, it was found that the coassembly of the peptides within the existing polysaccharide network resulted in a less stiff material as compared to the pure peptide networks (the elastic modulus G′ decreased from 90 to 10 kPa). However, these composite oligopeptide‐polysaccharide hydrogels were characterized by a greater resistance to deformation (the yield strain γ grew from 4 to 100%). Small‐angle neutron scattering (SANS) was used to study the 2D cross‐sectional shapes of the fibers, their dimensional characteristics, and the mesh sizes of the fibrous networks. Differences in material structures found with SANS experiments confirmed rheology data, showing that incorporation of the peptides dramatically changed the morphology of the polysaccharide network. The resulting fibers were structurally very similar to those forming the pure peptide networks, but formed less stiff gels because of their markedly greater mesh sizes. Together, these findings suggest an approach for the development of highly deformation‐resistant biomaterials. © 2011 Wiley Periodicals, Inc. Biopolymers 97: 177–188, 2012.
Genetic association of the Phosphoinositide‐3 kinase in schizophrenia and bipolar disorder and interaction with a BDNF gene polymorphism
Authors: Carrard Anthony , Salzmann Annick , Perroud Nader , Gafner Jérémie , Malafosse Alain , Karege Félicien
Published: October 2011

Phosphoinositide‐3‐kinase, class III (PIK3C3) is a member of the phosphoinosite‐3‐kinases family, involved in cell signaling, membrane trafficking, and neurodevelopment. Previous studies have indeed shown an association between PIK3C3 gene variants and both bipolar disorder (BD) and schizophrenia (SZ). Brain‐derived neurotrophic factor (BDNF) is a neurodevelopmental factor, which can regulate the PI3K signaling pathway. Associations have been reported between BDNF gene polymorphisms and affective and psychotic disorders. The aim of the present study was to replicate an association between PIK3C3 and BDNF gene variants in SZ and BD and a putative epistasis between the two genes. Patients meeting the DSM‐IV criteria of BD and SZ were included in this study (98 BD and 79 SZ) as well as 158 healthy controls. Blood DNA was extracted and genotyping was performed either by the polymerase chain reaction (PCR) technique followed by enzymatic digestion or by the high‐resolution melt (HRM) method. Genotype and haplotype association was assessed with the UNPHASED statistical program.The results showed one nominal association with BD (P < 0.02) and two risk haplotypes in both SZ (P < 0.001) and BP (P < 0.0005), which survived multiple testing correction. A modest interaction between a BDNF variant and PI3KC3 polymorphism was observed (P < 0.04).These preliminary results confirm the genetic association of PI3K gene variants with both SZ and BD, and support the hypothesis that SZ and BD share a genetic background.
Structure‐Based Discovery of Allosteric Modulators of Two Related Class B G‐Protein‐Coupled Receptors
Authors: de Graaf Chris , Rein Chantal , Piwnica David , Giordanetto Fabrizio , Rognan Didier
Published: October 2011

Despite the availability of X‐ray crystal structure data for several members of the G‐protein‐coupled receptor (GPCR) superfamily, structure‐based discovery of GPCR ligands has been exclusively restricted to class A (rhodopsin‐like) receptors. Herein we report the identification, by a docking‐based virtual screening approach, of noncompetitive ligands for two related class B (secretin‐like) GPCRs: the glucagon receptor (GLR) and the glucagon‐like peptide 1 receptor (GLP‐1R). Starting from a knowledge‐based three‐dimensional model of the GLR, a database of 1.9 million commercially available drug‐like compounds was screened for chemical similarity to existing GLR noncompetitive antagonists and docked to the transmembrane cavity of the GLR; 23 compounds were then selected based on protein–ligand interaction fingerprints, and were then purchased and evaluated for in vitro binding to GLR and modulation of glucagon‐induced cAMP release. Two of the 23 compounds inhibited the effect of glucagon in a dose‐dependent manner, with one inhibitor exhibiting the same potency as L‐168 049, a reference noncompetitive GLR antagonist, in a whole‐cell‐based functional assay. Interestingly, one virtual hit that was inactive at the GLR was shown to bind to GLP‐1R and potentiate the response to the endogenous GLP‐1 ligand.
Structures, Energetics and Vibrational Frequency Shifts of Hydrated Pyrimidine
Authors: Howard J. Coleman , Hammer Nathan I. , Tschumper Gregory S.
Published: October 2011

More than 70 unique micro‐hydrated structures of pyrimidine, ranging in size from 1 to 7 water molecules, have been characterized with the B3LYP density functional and the 6‐311++G(2df,2pd) triple‐ζsplit‐valence basis set. Explicitly correlated MP2‐F12 single‐point computations were performed on each structure with a correlation consistent triple‐ζbasis set to estimate the relative and dissociation energies at the MP2 complete basis set (CBS) limit. Many of these new structures have significantly lower energies than those previously reported (by as much as 12.66 kcal mol−1). For clusters with 1 and 2 water molecules, the MP2‐F12 relative and dissociation energies are virtually identical to the corresponding CCSD(T)‐F12 values. As the number of hydrating waters increases, the structures in which the water molecules are clustered together at one of the N atoms have lower energies than those where the water molecules are more distributed around the pyrimidine ring. Micro‐hydrated structures that effectively extend the low‐energy hydrogen‐bonding motifs to both sides of the ring, as would be expected in the bulk phase, reproduce the experimentally observed vibrational frequency shifts ofν1andν8bin very dilute aqueous pyrimidine solutions to within 1 cm−1. Micro‐hydrated structures of pyrimidine in which water molecules are clustered together have lower energies than structures in which the water molecules are more evenly spread around the pyrimidine ring.
Practice note: Is mediation suitable for complaints of workplace bullying?
Authors: Jenkins Moira
Published: October 2011

This article draws on research that sheds light on whether mediation is an appropriate intervention in complaints of workplace bullying. The different types of bullying that can be perpetrated are discussed. While mediation may be appropriate for most bullying complaints, when used alone it fails to address the antecedents that have been identified as contributing both to the development and maintenance of workplace bullying. This article examines these antecedents and argues that the sustainability of mediated outcomes may be at risk if mediation is used as the sole intervention to address complaints of workplace bullying.
Navigating the unchartered waters of cross‐cultural conflict resolution education
Authors: Loode Serge
Published: October 2011

This article suggests that culturally appropriate conflict resolution education in cross‐cultural settings can best be achieved through a dialogical approach to education. The article briefly summarizes the discussion about the connection between culture and conflict resolution and presents the two mainstream approaches to conflict resolution training: the prescriptive and the elicitive approach.
Practice note: Informal mediation in China
Authors: Faure Guy Olivier
Published: October 2011

Everywhere in the world, daily life provides abundant cases of conflict. Common events may turn into a real show when highlighted by some exotic colors such as those produced by Chinese strategies. Thus, a mediation addressing a conflict following a traffic accident can be quite revelatory of how Chinese culture approaches disputes. The following account comes from direct observation completed by interviews of onlookers.
Conservation priorities of genetic diversity in domesticated metapopulations: a study in taurine cattle breeds
Authors: Medugorac Ivica , Veit‐Kensch Claudia E. , Ramljak Jelena , Brka Muhamed , Marković Božidarka , Stojanović Srđan , Bytyqi Hysen , Kochoski Ljupche , Kume Kristaq , Grünenfelder Hans‐Peter , Bennewitz Jörn , Förster Martin
Published: October 2011

We estimated neutral diversity of 21 European cattle breeds with 105 microsatellites. Nine of them resembled unselected Balkan Buša strains with diffuse breeding barriers and the 12 others were strongly differentiated, isolated breeds. Because of the impact of neutral genetic diversity on long‐term population adaptive capacity, we discuss the long‐term outcome of different conservation priorities in a subdivided metapopulation of the investigated cattle breeds. The optimal contribution to a pool of total genetic diversity allocated more than 95% of long‐term relevant neutral diversity to virtually unselected strains of the Balkan Buša, while the maximization of total variance preferred inbred breeds. Current artificial selection methods, such as genomic selection sped up and a recovery of underestimated traits becomes quickly impossible. We emphasize that currently neutral and even deleterious alleles might be required for future genotypes in sustainable and efficient livestock breeding and production systems of a 21st century. We provide cumulative evidences that long‐term survival relies on genetic complexity and complexity relies on allelic diversity. Our results suggest that virtually unselected, nonuniform strains harbor a crucial proportion of neutral diversity and should be conserved with high global priority. As one example, we suggest a cooperative maintenance of the nondifferentiated, highly fragmented, and fast vanishing metapopulation of Balkan Buša.
Nocturnal water loss in mature subalpine Eucalyptus delegatensis tall open forests and adjacent E. pauciflora woodlands
Authors: Buckley Thomas N. , Turnbull Tarryn L. , Pfautsch Sebastian , Adams Mark A.
Published: October 2011

We measured sap flux (S) and environmental variables in four monospecific stands of alpine ash (Eucalyptus delegatensis R. Baker, AA) and snowgum (E. pauciflora Sieb. ex Spreng., SG) in Australia's Victorian Alps. Nocturnal S was 11.8 ± 0.8% of diel totals. We separated transpiration (E) and refilling components of S using a novel modeling approach based on refilling time constants. The nocturnal fraction of diel water loss (fn
) averaged 8.6 ± 0.6% for AA and 9.8 ± 1.7% for SG; fn
differed among sites but not species. Evaporative demand (D) was the strongest driver of nocturnal E (En
). The ratio En
/D (Gn
) was positively correlated to soil moisture in most cases, whereas correlations between wind speed and Gn
varied widely in sign and strength. Our results suggest (1) the large, mature trees at our subalpine sites have greater fn
than the few Australian native tree species that have been studied at lower elevations, (2) AA and SG exhibit similar fn
despite very different size and life history, and (3) fn
may differ substantially among sites, so future work should be replicated across differing sites. Our novel approach to quantifying fn
can be applied to S measurements obtained by any method.