bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal patterns in diversity and abundance of the High Antarctic meroplankton: Plankton sampling using a Ross Sea desalination plant
Authors: Sewell Mary A. , Jury Jennifer A.
Published: July 2011

The Antarctic marine environment is thermally stable, yet shows pronounced seasonality in the light : dark cycle, primary productivity, and the extent of sea‐ice cover. Thorson's Rule, predicting reduced meroplankton diversity at high latitudes, was based on the perceived difficulties in completing larval development at low temperatures and within the short summer period of phytoplankton production. Yet few studies have addressed seasonal patterns in Antarctic meroplankton diversity and abundance, especially in the High Antarctic. Here we circumvented logistical difficulties in conducting winter plankton sampling by using the 100‐µm primary filter on the desalination plant at Scott Base in McMurdo Sound, Ross Sea (77°51′S), to sample embryos and larvae. Using samples from an entire calendar year we found no seasonal changes in either embryo or larval operational taxonomic unit (OTU) diversity with season, no seasonal changes in embryo abundance (5000 L−1), but a peak in larval abundance during the period of the summer phytoplankton bloom (maximum 295 larvae 5000 L−1). While some OTUs showed a strong seasonality, there was also a high diversity of both embryos and larvae during the autumn and winter, and some OTUs were present in the meroplankton year‐round. Annelids, molluscs, and echinoderms were dominant members of the Ross Sea meroplankton, showing similar prevalence to that seen at Signy (60°43′S) and Adelaide Islands (67°34.5′S). The use of the desalination plant primary filter allows plankton samples to be collected year‐round, even in the High Antarctic with permanent sea‐ice and 4 months of 24‐h darkness.
Auger Electron Spectroscopic Studies on Oxide Films of Some Austenitic Stainless Steels
Authors: Cahoon J. R. , Bandy R.
Published: July 2011

Auger electron spectroscopic studies on the surface film of three different austenitic stainless steels revealed that the surface composition of the film which had been formed in Ringer's physiological solution was almost independent of the bulk composition of the alloy. The surface concentration of Mo was essentially zero for bulk Mo concentrations of 1.3 and 2.8 At%. The surface concentration of Ni was essentially zero for a bulk composition of 10 At% and may have reached a few At% for a bulk concentration of 24 At%. The surface composition of films passivated at the rest potential for 4 days in chloride solution was found to be about 10 At% Fe, 55 At% 0, 35 At% Cr and was essentially independent of bulk composition of the steel. The reasons for the beneficial effect of Mo additions in increasing resistance to pitting corrosion remain unclear.
Electrochemical (Corrosion) Behavior of Amorphous/Microcrystalline Ion Plated Fe-Cr Alloy Films
Authors: Nowak Welville B. , Okorie Boniface A.
Published: July 2011

Amorphous and microcrystalline thin films of chromium-bearing iron alloys produced by ion plating exhibit high resistance to localized (pitting) corrosion in neutral NaCl aqueous solutions. The films are produced by thermal evaporation of the alloys through an argon glow discharge onto Ebrite (Fe-Cr) substrates maintained at low temperatures. Potentiodynamic tests indicate that the ion plated films exhibit a Tafel-like behavior in the “passive” potential range, whereas Ebrite and melt-spun amorphous alloys of composition similar to the films have a constant current passive region. Transient current data obtained from tests at successively higher potentiostatic voltages (V) show that such currents decrease exponentially with time. The current relaxation time constant (τ) of the films are five to ten times larger than those of Ebrite, and increases rapidly with V up to about 0.3 V, decreasing slowly thereafter. For the Ebrite substrate, τ shows only increasing values, but with a sharp discontinuity in the V versus τ curve at about 0.4 V. Transient data obtained for bulk amorphous Metglas 2826A above 0.5 V shows that the variation of τ with V is similar to that of the ion plated films. The results indicate that it takes longer to complete the passive layer on the ion plated films than on the crystalline substrate; the decrease in τ with increasing V in the middle potential region may be related to the amorphous or amorphous/microcrystalline structure of Metglas 2826A and the ion plated films. The results are consistent with a change in the character of the passive layer at 0.3 to 0.4 V.
On the Nature of the Occluded Cell in the Stress Corrosion Cracking of AA 7075-T651—Effect of Potential, Composition, Morphology
Authors: Nguyen T. H. , Brown B. F. , Foley R. T.
Published: July 2011

The SCC of AA 7075-T651 has been investigated in various electrolytes at different applied potentials. The rate of crack growth in the precracked, double cantilever beam, specimen was measured and related to the aluminum ion concentration and pH within the crack as well as the morphology of the crack wall surface as viewed with a scanning electron microscope. The rate of crack growth, the composition of the solution within the crack, and the morphology of the crack wall are determined mainly by the anion in solution and this in terms of the aluminum-anion complexes formed during the reaction. In sodium chloride solution, the pH at the crack tip was acidic at the open circuit and in the anodic potential range while, in the cathodic range, it was basic. At anodic potentials, the aluminum ion concentration reached 0.4M within the crack. In Na2SO4 solution, crack propagation was very slow at the open circuit and at anodic potentials even though the pH at the crack tip was acidic. However, when the potential was shifted into a cathodic range, the crack began to propagate at an appreciable rate. In NaNO3 solutions, crack propagation rate increased in the cathodic range due to the formation of ammonia within the crack. Very slow crack growth was observed in the anodic range. The analysis of the solution within a simulated crevice indicated that the composition of the solution in a simulated crevice and an actual stress corrosion crack were quite similar.
An Accelerated Intergranular Corrosion Test for Detecting Sensitization in Low Chromium Ferritic Stainless Steels
Authors: Devine T. M. , Drummond B. J.
Published: July 2011

The procedure for developing an accelerated corrosion test which would aid in assessing the sensitization resistance of low chromium ferritic stainless steels is described. Immersion corrosion tests were conducted on Fe-Cr binary alloys in boiling acidified Cu-CuSO4 solutions. Reducing the H2SO4 concentration of the standard ASTM A262E solution results in a reduction in the minimum chromium content required for passivation. In a boiling solution containing 0.5 w/o H2SO4 + 6 w/o CuSO4 + Cu chips, alloys with > 12 w/o chromium are passive and alloys with < 12 w/o chromium undergo general attack. The 0.5 w/o H2SO4 solution is shown to be useful in evaluating the time-temperature-sensitization behavior of a 12 w/o chromium ferritic stainless steel.
Effects of Overloads on the Incubation Time for Stress Corrosion Cracking of 7075 Aluminum
Authors: Hanisch A. H. , Burck L. H.
Published: July 2011

A series of tests was conducted on precracked high strength aluminum alloy 7075-T651 plate to determine the effects of overstressing on the short-transverse stress corrosion cracking behavior. Fatigue precracked wedge-opening-loading specimens were preloaded in air to various percentages of the critical stress intensity factor, unloaded, and reloaded statically to lower stress intensity factor levels. The samples were then alternately immersed in an aqueous 3.5% sodium chlorine solution for stress corrosion testing. The incubation time which preceded crack extension by stress corrosion cracking was found to increase substantially for higher percentages of preloading. Furthermore, for a given percentage of prestress overload, greater effects were observed for higher applied stress intensity factor levels. The increase in incubation period produced by stress overloading is attributed primarily to the effects of residual compressive stresses at the crack tips.
Simulation of the mineral dust content over Western Africa from the event to the annual scale with the CHIMERE-DUST model
Authors: Schmechtig C. , Marticorena B. , Chatenet B. , Bergametti G. , Rajot J. L. , Coman A.
Published: July 2011

Abstract. The chemistry and transport model CHIMERE-DUST have been used to simulate the mineral dust cycle over the Sahara in 2006. Surface measurements deployed during the AMMA field campaign allow to test the capability of the model to correctly reproduce the atmospheric dust load and surface concentrations from the daily to the seasonal time-scale. The simulated monthly mean Aerosol Optical Depths (AOD) and surface concentrations are significantly correlated with the measured ones. The simulated daily concentrations and hourly AOD are in the same range of magnitude than the observed ones despite relatively high simulated dust emissions. The level of agreement between the simulations and the observations has been quantified at different time scales using statistical parameters classically used to evaluate air quality models. The capability of the model to reproduce the altitude of the dust transport was tested for two contrasted cases of low and high altitude transport. These results highlight the sensitivity of the simulations to the surface winds used as external forcing and the necessity to further constrain the dust mass budget at the regional scale.
Dust from the dark region in the western ablation zone of the Greenland ice sheet
Authors: Wientjes I. G. M. , Van de Wal R. S. W. , Reichart G. J. , Sluijs A. , Oerlemans J.
Published: July 2011

Abstract. A dark region tens of kilometres wide is located in the western ablation zone of the Greenland ice sheet. The dark appearance is caused by higher amounts of dust relative to the brighter surroundings. This dust has either been deposited recently or was brought to the surface by melting of outcropping ice. Because the resulting lower albedos may have a significant effect on melt rates, we analysed surface dust on the ice, also called cryoconite, from locations in the dark region as well as locations from the brighter surrounding reference ice with microscopic and geochemical techniques to unravel its composition and origin. We find that (part of) the material is derived from the outcropping ice, and that there is little difference between dust from the dark region and from the reference ice. The dust from the dark region seems enriched in trace and minor elements that are mainly present in the current atmosphere because of anthropogenic activity. This enrichment is probably caused by higher precipitation and lower melt rates in the dark region relative to the ice marginal zone. The rare earth elemental ratios of the investigated material are approximately the same for all sites and resemble Earth's average crust composition. Therefore, the cryoconite probably does not contain volcanic material. The mineralogical composition of the dust excludes Asian deserts, which are often found as provenance for glacial dust in ice cores, as source regions. Consequently, the outcropping dust likely has a more local origin. Finally, we find cyanobacteria and algae in the cryoconite. Total Organic Carbon accounts for up to 5 weight per cent of the cryoconite from the dark region, whereas dust samples from the reference ice contain only 1 % or less. This organic material is likely formed in situ. Because of their high light absorbency, cyanobacteria and the organic material they produce contribute significantly to the low albedo of the dark region.
Test for dispersion constancy in stochastic differential equation models
Authors: Lee Sangyeol , Guo Meihui
Published: July 2011

In this paper, we propose a constancy test for volatility in It processes based on discretely sampled data. The test statistic constitutes an integration of the Ljung–Box test statistic and the kurtosis statistic in the Jarque–Bera test. It is shown that under regularity conditions, the proposed test asymptotically follows a chi‐square distribution under the null hypothesis of constant volatility. To evaluate the test, empirical sizes and powers were examined through a simulation study. Analysis of real data including ultra‐high frequency transaction data and interest rates was also conducted for illustration. Copyright © 2011 John Wiley & Sons, Ltd.
Dependence of the order and crack density of polystyrene opals on volume fraction, humidity and temperature
Authors: Pérez N. , Sanza F. J. , Rodríguez A. , Olaizola S. M.
Published: July 2011

We have fabricated polystyrene opals by vertical deposition with colloidal spheres of 419 nm in diameter. Different parameters such as the concentration, temperature and relative humidity have been systematically varied in order to study the dependence of the crystalline quality of the opals on these parameters. The opals have been optically and structurally characterized, paying particular attention to the size and distribution of the domains for each fabrication condition. We have noticed a dependence of the size of the domains on the thickness which corroborates a previous study. From these results we can conclude that the characterization of the homogeneity of the thickness of the opals can be done just by using microscopy. We also report a dependence of the order of the opals on relative humidity and a selective adhesion of the opals to the substrate depending on concentration and surface chemistry. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Controllable mineralization of calcium carbonate on regenerated cellulose fibers
Authors: Xiao Wenjun , Liu Jie , Chen Qin , Wu Ying , Dai Lizong , Wu Tinghua
Published: July 2011

Gel–forming fibers (GF fibers) can serve as nucleation sites to prepare calcium carbonate (CaCO3) because they can adsorb large amounts of Ca2+ due to their porous structure. In this paper, mineralization behavior of CaCO3 on GF fibers in ethanol–water mixed solvents without any additives has been investigated. The results showed that some crystals covered the fibers, while others were embedded in fibers. Twin–sphere based vaterite, zonary and rodlike calcite with large aspect ratio could be prepared successfully. The effect of ethanol content inside GF fibers, concentration of Ca2+ and CO32‐, mineralization time, miscibility between alcohol and water, and temperature were studied. Lastly, a possible mineralization mode was suggested. This work could provide a new method to prepare inorganic/polymer hybrid materials. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis of ZnSn(OH)6 regular octahedrons by a simple hydrothermal process
Authors: Yu Xiujun , Lu Hongxia , Li Qi , Zhao Yunlong , Chen Deliang , Fan Bingbing , Wang Hailong , Yang Daoyuan , Xu Hongliang , Zhang Rui
Published: July 2011

ZnSn(OH)6 regular octahedrons were successfully synthesized through a simple hydrothermal method using an aqueous solution containing ZnO flower‐like structures, SnCl4·5H2O, and NaOH. Phase structure, morphology and microstructure of the samples were investigated by X‐ray diffraction (XRD) and scanning electron microscopy (SEM). Parameters in preparation process such as the ratios of Sn4+/OH‐, the molar ratio of Zn/Sn and reaction time were discussed. Results show that the obtained samples are comprised of ZnSn(OH)6 regular octahedrons with about 2 μm in side length and ZnSn(OH)6 urchins‐like structures. ZnSn(OH)6 urchins‐like structures preferentially grow on the edges and corners of regular octahedrons. Morphology of the products is susceptible to the ratios of Sn4+/OH‐. A relatively low concentration of OH‐ is favored to obtain ZnSn(OH)6 regular octahedrons with urchins‐like structures on the surface, while a high concentration of OH‐ results in a handful of regular octahedrons without urchins‐like structures on the surface. When the molar ratio of Zn/Sn changes to 1:2 or 2:1, the edges and corners of regular octahedrons become coarse and urchins‐like structures disappear from the surface. More urchins‐like structures form on the surface of regular octahedrons and the edges and corners of regular octahedrons become coarsened with the increase of reaction time. Moreover, the possible mechanism for ZnSn(OH)6 regular octahedrons is discussed. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Decentralized estimation over noisy channels in cluster‐based wireless sensor networks
Authors: Liu Guiyun , Xu Bugong , Chen Hongbin
Published: July 2011

In this paper, the problem of decentralized parameter estimation over noisy channels in a cluster‐based sensor network is studied. Each cluster head generates a local estimate by adopting a sample mean estimator. The local estimates from all cluster heads are compressed by using a one‐bit quantizer and then the bits are transmitted to a fusion center over independent binary symmetric channels. Two maximum likelihood estimators are proposed for estimating the parameter based on the received bits in two different scenarios: (i) all clusters have the same number of cluster members and (ii) the number of cluster members in the clusters are different. The Cramér–Rao lower bounds for the proposed estimators in both scenarios are derived. Simulation results show that the estimation performance for clustering with the same number of cluster members can be comparable to that for cluster‐free sensor networks. However, the estimation performance for clustering with a different number of cluster members is not as good as that for cluster‐free sensor networks. The trade off between estimation performance and energy consumption exists in both scenarios. The energy consumed for executing the estimation task in cluster‐based sensor networks is less than that in cluster‐free sensor networks. Copyright © 2011 John Wiley & Sons, Ltd.
Cognitive and clinical outcomes of homocysteine‐lowering B‐vitamin treatment in mild cognitive impairment: a randomized controlled trial
Authors: de Jager Celeste A. , Oulhaj Abderrahim , Jacoby Robin , Refsum Helga , Smith A. David
Published: July 2011

Background

Homocysteine is a risk factor for Alzheimer's disease. In the first report on the VITACOG trial, we showed that homocysteine‐lowering treatment with B vitamins slows the rate of brain atrophy in mild cognitive impairment (MCI). Here we report the effect of B vitamins on cognitive and clinical decline (secondary outcomes) in the same study.

Methods

This was a double‐blind, single‐centre study, which included participants with MCI, aged ≥70 y, randomly assigned to receive a daily dose of 0.8 mg folic acid, 0.5 mg vitamin B12 and 20 mg vitamin B6 (133 participants) or placebo (133 participants) for 2 y. Changes in cognitive or clinical function were analysed by generalized linear models or mixed‐effects models.

Results

The mean plasma total homocysteine was 30% lower in those treated with B vitamins relative to placebo. B vitamins stabilized executive function (CLOX) relative to placebo (P = 0.015). There was significant benefit of B‐vitamin treatment among participants with baseline homocysteine above the median (11.3 µmol/L) in global cognition (Mini Mental State Examination, P < 0.001), episodic memory (Hopkins Verbal Learning Test–delayed recall, P = 0.001) and semantic memory (category fluency, P = 0.037). Clinical benefit occurred in the B‐vitamin group for those in the upper quartile of homocysteine at baseline in global clinical dementia rating score (P = 0.02) and IQCODE score (P = 0.01).

Conclusion

In this small intervention trial, B vitamins appear to slow cognitive and clinical decline in people with MCI, in particular in those with elevated homocysteine. Further trials are needed to see if this treatment will slow or prevent conversion from MCI to dementia. Copyright © 2011 John Wiley & Sons, Ltd.
Self‐Healing Behavior of Blends Based on Ionomers with Ethylene/Vinyl Alcohol Copolymer or Epoxidized Natural Rubber
Authors: Rhaman Md. Arifur , Penco Maurizio , Spagnoli Gloria , Grande Antonio Mattia , Di Landro Luca
Published: July 2011

The effect of blending on the self‐healing behavior of an ethylene/methacrylic acid copolymer ionomer is investigated. Binary EMNa/EVA and EMNa/ENR blends are studied by ballistic puncture tests. In the composition range explored (15–50 wt% of EVA and ENR), the self‐healing characteristics decrease with increasing amount of EVA but are maintained in the whole range for EMNa/ENR blends. The bullet impact zones were observed using OM. Tensile tests showed that the blending process gives the opportunity to tune the mechanical characteristics without significant loss in the self‐healing properties, particularly in EMNa/ENR blends. Component compatibility, blend morphology and thermal properties were studied using DSC, SEM, and DMTA. Molecular interactions between the phases in the blends are discussed.

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Phosphorylcholine‐Substituted ROMP Polyolefin Coatings Provide Fouling Resistance to Membrane Materials
Authors: Kratz Katrina , Xie Wei , Lee Albert , Freeman Benny D. , Emrick Todd
Published: July 2011

The design and synthesis of new fouling‐resistant coating materials, specifically PC‐substituted polyolefins, and their application to water purification membranes is described. Greatly improved fouling resistance is found for coated membranes subjected to environmentally relevant emulsified oil foulants. The coating method proves effective for reducing fouling on both UF and RO membranes, and for maintaining high rejection of organic material and salt. Providing membranes of various types with a coating that simultaneously gives high flux, fouling resistance, and foulant rejection represents a significant advance in membrane materials, and a promising route to extend membrane applications beyond what has been possible using conventional, known materials.

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Effect of Chemical Composition on the Deformability of Shape‐Memory Epoxies
Authors: Feldkamp Diane M. , Rousseau Ingrid A.
Published: July 2011

Newly developed shape memory (SM) epoxies are unveiled with an improved deformability range, high strength with intrinsically good thermal and chemical stability, high thermal transition (i.e., SM transformation temperature), and qualitatively excellent SM characteristics, thereby providing a synthetic route for adding attractive properties to commonly used industrial and commodity resins. The impact of chemical composition on the failure strains of these SM epoxies is shown and the resulting SM behavior is discussed.

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Development and Long‐Term In Vivo Evaluation of a Biodegradable Urethane‐Doped Polyester Elastomer
Authors: Dey Jagannath , Tran Richard T. , Shen Jinhui , Tang Liping , Yang Jian
Published: July 2011

A detailed report on the development of CUPE polymers synthesized using diols with 4, 6, 8, 10, or 12 methylene units is presented with the aim of elucidating the influence of the diol component on the physical properties of the resulting material and assessing their long‐term biological performance in vivo. Increasing the diol length leads to lower crosslinking densities, higher hydrophobicities, higher tensile strengths and elasticities, and slower polymer degradation. The choice of diol does not affect the overall cell/tissue compatibility both in vitro and in vivo. The diol component is thus established as an important parameter in controlling the structure/property relationships of the polymers, thereby increasing the choice of biodegradable elastomers for tissue engineering applications.

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Some fully nonlinear elliptic boundary value problems with ellipsoidal free boundaries
Authors: Enache Cristian , Sakaguchi Shigeru
Published: July 2011

In this paper we study some overdetermined boundary value problems for three classes of fully nonlinear elliptic equations. In each case we prove that the solution exists if and only if the underlying domain is the interior of an ellipsoid (or ellipse in two dimensions). The proofs make use of the uniqueness theorem, maximum principles or some geometric arguments involving the curvatures of the free boundary. © 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
On models of irreducible p,q‐representations of gl(2) and p,q‐Mellin integral transformation
Authors: Sahai Vivek , Yadav Sarasvati
Published: July 2011

We construct new two variable models of the irreducible p, q‐representations of the four dimensional complex Lie algebra gl(2). These models are formed in terms of p, q ‐derivative operator and dilation operators. The p, q‐Mellin integral transformation is defined and is used to transform these models in the form of p, q‐difference dilation models. All the models culminate in many special function identities and recurrence relations. © 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
On the Similarities of Some Multi‐Criteria Decision Analysis Methods
Authors: Geldermann Jutta , Schöbel Anita
Published: July 2011

Since multiple criteria characterise many practical decision problems, the research field of multicriteria decision analysis (MCDA) is flourishing. This paper compares the multi‐attribute decision making (MADM) methods, simple additive rating (SAR), simple additive weighting (SAW) as well as the outranking approach PROMETHEE and explains their similarities. We present a case study on industrial paint application and provide theoretical evidence that PROMETHEE can mimic other MADM algorithms. Copyright © 2011 John Wiley & Sons, Ltd.
General Further Discarding Tests in Geometric Branch‐and‐Bound Methods for Non‐Convex Multicriteria Optimization Problems
Authors: Scholz Daniel
Published: July 2011

Using a geometric branch‐and‐bound technique, my goal in this paper is to compute a sharp outer approximation of all Pareto‐optimal solutions in multicriteria optimization problems. To this end, I propose some general further discarding tests that are based on the Fritz John necessary conditions for Pareto optimality.

The branch‐and‐bound solution method as well as the general further discarding tests leads to a very useful tool especially for multicriteria facility location problems. Therefore, my suggested approach is demonstrated on some multicriteria facility location problems with excellent numerical results. Copyright © 2011 John Wiley & Sons, Ltd.
Comparability of Self–Reported Conscientiousness across 21 Countries
Authors: Mõttus René , Allik Jüri , Realo Anu , Pullmann Helle , Rossier Jérôme , Zecca Gregory , Ah–Kion Jennifer , Amoussou–Yéyé Dénis , Bäckström Martin , Barkauskiene Rasa , Barry Oumar , Bhowon Uma , Björklund Fredrik , Bochaver Aleksandra , Bochaver Konstantin , de Bruin Gideon P. , Cabrera Helena F. , Chen Sylvia Xiaohua , Church A. Timothy , Cissé Daouda Dougoumalé , Dahourou Donatien , Feng Xiaohang , Guan Yanjun , Hwang Hyi–Sung , Idris Fazilah , Katigbak Marcia S. , Kuppens Peter , Kwiatkowska Anna , Laurinavicius Alfredas , Mastor Khairul Anwar , Matsumoto David , Riemann Rainer , Schug Joanna , Simpson Brian , Ng Tseung Caroline
Published: July 2011

In cross–national studies, mean levels of self–reported phenomena are often not congruent with more objective criteria. One prominent explanation for such findings is that people make self–report judgements in relation to culture–specific standards (often called the reference group effect), thereby undermining the cross–cultural comparability of the judgements. We employed a simple method called anchoring vignettes in order to test whether people from 21 different countries have varying standards for Conscientiousness, a Big Five personality trait that has repeatedly shown unexpected nation–level relationships with external criteria. Participants rated their own Conscientiousness and that of 30 hypothetical persons portrayed in short vignettes. The latter type of ratings was expected to reveal individual differences in standards of Conscientiousness. The vignettes were rated relatively similarly in all countries, suggesting no substantial culture–related differences in standards for Conscientiousness. Controlling for the small differences in standards did not substantially change the rankings of countries on mean self–ratings or the predictive validities of these rankings for objective criteria. These findings are not consistent with mean self–rated Conscientiousness scores being influenced by culture–specific standards. The technique of anchoring vignettes can be used in various types of studies to assess the potentially confounding effects of reference levels. Copyright © 2011 John Wiley & Sons, Ltd.
Density functional theory study of silole‐fused tetramethyleneethane biradicals with orbital interactions
Authors: Kano Yusuke , Mizuno Kazuhiko , Ikeda Hiroshi
Published: July 2011

The geometries, energy gap between singlet and triplet states (S–T gap), electronic transitions, and molecular orbitals of the diphenyl derivative of the silole‐fused tetramethyleneethane (TME) (3,4‐dimethylenesilole) biradical 7•• were determined by using the density functional theory method at the unrestricted Becke, three‐parameter, Lee–Yang–Parr/cc‐pVDZ level. In a manner similar to that of the parent TME biradical, the S–T gap of 7•• is small. The wavelengths of electronic transitions of 37•• (λET = 450 nm) are calculated to be different from that of 17•• (λET = 673 nm). These differences are attributed to interactions between orbitals of the two allyl radical moieties, especially, the existence of double σ*–π* conjugation, that is, π*–σ*–π* conjugation, that takes place in the silole subunit. Copyright © 2011 John Wiley & Sons, Ltd.
Bile aspiration cytology in diagnosis of bile duct carcinoma: factors associated with positive yields
Authors: Abdelghani Yasser A. , Arisaka Yoshifumi , Masuda Daisuke , Takii Michiaki , Ashida Reiko , Makhlouf Madeha M. , Fouad Yasser M. , Tsuji Motomu , Kurisu Yoshitaka , Higuchi Kazuhide
Published: July 2011

Background/Purpose

In bile duct carcinoma (BDC) patients, bile aspiration cytology (BAC) is an established method for cytodiagnosis. However, almost all previous reports investigated the biliary strictures caused not only by BDC but also by gallbladder and pancreatic carcinomas. Therefore, BAC in BDC patients only has not yet been investigated sufficiently. The aim of this study was to evaluate the actual sensitivity of BAC and to evaluate the factors that affect positive yields of BAC in patients with defined BDC.

Methods

Data on 47 consecutive patients with definite BDC, who underwent BAC via endoscopic nasobiliary drainage (ENBD) or percutaneous transhepatic cholangiodrainage (PTCD), were retrospectively collected. Fourteen factors were studied for association with positive BAC.

Results

The number of cytological samplings ranged from 1 to 14 times. The cumulative diagnostic yield was 72.3% (34/47), and 32 positive results were obtained at a maximum of six samplings. Independent factors associated with positive BAC were perihilar location, stricture length ≥2 cm, and macroscopic papillary type.

Conclusion

In BDC patients with ENBD or PTCD, repeated BAC is useful, and six times was the optimum number of repeat samplings. Although the sensitivity of BAC is not sufficient for the preoperative diagnosis of malignant biliary stricture, the three independent factors noted above predict positive yields and indicate whether or not BAC should be repeated up to six times.
Responses of Trachelospermum asiaticum (Apocynaceae) seedlings to growth in a light intensity gradient
Authors: Kato Shogo , Yamamoto Takashi , Kawakubo Nobumitsu , Komiyama Akira
Published: July 2011

We recorded the growth of 24 seedlings of Trachelospermum asiaticum, a root climber, placed between a light source and a wall. Shoot length of seedlings planted at the brightest points nearly matched the distance the shoot tips moved toward the wall surface. In contrast, although the seedlings planted at the darkest points did elongate, the tips moved an average distance of only 0.4 cm. Creeping shoots of T. asiaticum planted in brighter environments exhibit negative phototropism, which encourages them to grow rapidly toward dark places, allowing them to reach supporting hosts faster than those that germinate close to the host.
Selfsimilar expanders of the harmonic map flow
Authors: Germain Pierre , Rupflin Melanie
Published: July 2011

We study the existence, uniqueness, and stability of self-similar expanders of the harmonic map heat flow in equivariant settings. We show that there exist selfsimilar solutions to any admissible initial data and that their uniqueness and stability properties are essentially determined by the energy-minimising properties of the so-called equator maps.

On étudie lʼexistence, lʼunicité et la stabilité de solutions auto-similaires issues dʼune singularité, pour le flot gradient des applications harmoniques, dans le cadre équivariant. On montre lʼexistence de telles solutions auto-similaires, et comment leurs propriétés dʼunicité et de stabilité sont étroitement reliées à la minimisation ou non de lʼénergie de Dirichlet par lʼapplication équateur.
Transcriptome profiling reveals a novel role for trichostatin A in antagonizing histone chaperone Chz1 mediated telomere anti‐silencing
Authors: Wan Yakun , Chen Weiming , Xing Jie , Tan Jinyin , Li Bing , Chen Huiying , Lin Zhanxian , Chiang Jung-Hsien , Ramsey Saleem
Published: July 2011

The histone chaperones play an important role in chromatin assembly and disassembly during replication and transcription. We have assessed the global roles of histone chaperones in Saccharomyces cerevisiae. Microarray transcriptional analyzes indicate that histone chaperones have their own specific target genes, and various histone chaperones have partially overlapping functions during transcriptional regulation. The histone deacetylase inhibitor TSA and histone chaperones Asf1, Vps75 and Rtt106 can function in parallel pathways to regulate transcription. Moreover, TSA can specifically antagonize histone chaperone Chz1‐mediated telomere anti‐silencing. This study demonstrates that a mutual cross‐talk mechanism exists between histone chaperones and histone deacetylation in transcriptional regulation.
Homotropic and heterotropic interactions in cytochromes c3 from sulphate reducing bacteria
Authors: Turner David L. , Catarino Teresa
Published: July 2011

This article reviews the contribution of António Xavier and his associates to the study of multihaem cytochromes. Detailed analysis of interactions between the charges of the haems and protonatable groups reveals that electrostatic effects may be outweighed by subtle changes in conformation. This helps us to understand how tetrahaem cytochromes c
3 work and also gives an insight into the mechanism of cytochrome c oxidase.
Atypical Clavicular Involvement of Nonbacterial Osteitis: An Orthopaedic Enigma
Authors: Salil Umrani , Wang Chow , Michael To Kai-Tsun
Published: July 2011

Nonbacterial osteitis (NBO) is an underdiagnosed and poorly understood condition caused by sterile inflammation. It can mimic the presentation of many other orthopaedic conditions, for example, osteomyelitis, septic arthritis, or malignancy, in particular for those patients who have unifocal presentation. Because NBO is a diagnosis by exclusion, it poses much difficulty and confusion to many orthopaedic surgeons in treating such disease. Clavicular involvement is common but it is typically present at the medial aspect of the clavicle. We report a case of NBO with atypical clavicular involvement who presented to our orthopaedic clinic with painful swelling in the left shoulder. Appropriate investigations and management are discussed together with literature review.
Measuring the departures from the Boussinesq approximation in Rayleigh–Bénard convection experiments
Authors: KURTULDU H. , MISCHAIKOW K. , SCHATZ M. F.
Published: July 2011

Algebraic topology (homology) is used to characterize quantitatively non-Oberbeck–Boussinesq (NOB) effects in chaotic Rayleigh–Bénard convection patterns from laboratory experiments. For fixed parameter values, homology analysis yields a set of Betti numbers that can be assigned to hot upflow and, separately, to cold downflow in a convection pattern. An analysis of data acquired under a range of experimental conditions where NOB effects are systematically varied indicates that the difference between time-averaged Betti numbers for hot and cold flows can be used as an order parameter to measure the strength of NOB-induced pattern asymmetries. This homology-based measure not only reveals NOB effects that Fourier methods and measurements of pattern curvature fail to detect, but also permits distinguishing pattern changes caused by modified lateral boundary conditions from NOB pattern changes. These results suggest a new approach to characterizing data from either experiments or simulations where NOB effects are expected to play an important role.
THE DARKER SIDE OF TRANSITIONAL JUSTICE: THE POWER DYNAMICS BEHIND RWANDA'SGACACACOURTS
Authors: Thomson Susan
Published: July 2011

In this article, I argue that the praise of legal and political analysts who perceive Rwanda'sgacacacourts as a model of locally grounded and culturally relevant transitional justice is unfounded without consideration of the broader power dynamics in which justice is delivered. Drawing on life history interviews with 37 Rwandan peasants resident in the south-west of the country, I argue that the claims of the Rwandan government that itsgacacacourts are promoting peace and reconciliation must also assess the impact of local justice mechanisms on those subject to its demands, namely ordinary people. In the case of Rwanda'sgacacacourts, local-level analysis illuminates a darker and largely unexamined aspect of transitional justice – the playing out of local power dynamics and the social and political inequalities masked by the pursuit of justice and reconciliation. My study cautions against a wholesale endorsement of thegacacacourts as an effective and legitimate form of transitional justice. Instead, it is a mechanism of state power than works to reinforce the political power of the ruling RPF and to ply international audiences with the idea that Rwanda is ‘a nation rehabilitated’ from ‘the scourge of genocide’.
THE BRANDED ARENA: UGANDAN ‘TRADITIONAL’ DANCE IN THE MARKETING ERA
Authors: Pier David
Published: July 2011

Brand marketing in its latest global advances offers ideologies of public participation and the audience–‘provider’ relationship that many in the developing world are finding compelling, even when consumer capitalism fails to produce its promised rewards immediately. Strategies of ‘branding’ are being explored in combination with older performance strategies, with new syncretic branded arenas emerging as a result. In Africa, music and dance have always been important for establishing certain arenas and mediating transactions within them. In the era of post-independence nationalism, ‘traditional’ dances were itemized and made more disciplined and spectacular to give new states an aura of inclusiveness, rigour and historical depth. As the image of a powerful African state declines, these same dance traditions are being hitched to commercial brands, and to the globalized consumerist/entreprenurial dream. This article considers the Senator National Cultural Extravaganza, an annual traditional music-and-dance competition sponsored by East Africa Breweries Ltd, which requires participants to compose ‘local’ songs and dances in praise of Senator Extra Lager. It focuses on the spatial and temporal architectures of events and the way these channel, and are complicated by, the energies and significances of dance. The ‘textbook’ brand–consumer relationship does not, it is argued, survive wholly intact.
Stochastic simulation of the cost of home-produced feeds for ruminant livestock systems
Authors: FINNERAN E. , CROSSON P. , O'KIELY P. , SHALLOO L. , FORRISTAL D. , WALLACE M.
Published: July 2011

An agro-economic simulation model was developed to facilitate comparison of the impact of management, market and biological factors on the cost of providing ruminant livestock with feed grown on the farm (home produced feed). Unpredictable year-to-year variation in crop yields and input prices were identified as quantifiable measures of risk affecting feed cost. Stochastic analysis was used to study the impact of yield and input price risk on the variability of feed cost for eight feeds grown in Ireland over a 10-year period. Intensively grazed perennial ryegrass was found to be the lowest cost feed in the current analysis (mean cost €74/1000 Unité Fourragère Viande (UFV)). Yield risk was identified as the greatest single factor affecting feed cost variability. At mean prices and yields, purchased rolled barley was found to be 3% less costly than home-produced spring-sown barley. However, home-produced spring barley was marginally less risky than purchased barley (coefficient of variation (CV) 0·063 v. 0·064). Feed crops incurring the greatest proportion of fixed costs and area-dependent variable costs, including bunker grass silage, were the most sensitive to yield fluctuations. The most energy input-intensive feed crops, such as grass silage, both baled and bunker ensiled, were deemed most susceptible to input price fluctuations. Maize silage was the most risky feed crop (CV 0·195), with potential to be both the cheapest and the most expensive conserved feed.
The community associated with biogenic reefs formed by the polychaete, Serpula vermicularis
Authors: Chapman Nicola D. , Moore Colin G. , Harries Dan B. , Lyndon Alastair. R.
Published: July 2011

The study aims to provide the first detailed account of the diversity and composition of the community associated with biogenic reefs formed by serpulid worms. Ten reefs (aggregations of calcareous Serpula vermicularis tubes), spanning a broad size-range, were collected from Loch Creran, Scotland, a Special Area of Conservation designated principally for the protection of its biogenic reefs. Total faunal abundance was strongly linearly related to reef weight, whilst taxon richness exhibited a hyperbolic relationship with reef size. 278 taxa were recorded from the ten reefs, with a reef of 0.1 m2 area supporting 163 taxa and 12756 individuals, which appears to represent considerable augmentation of diversity and abundance for sedimentary areas of the loch where the reefs occur. The reef assemblage was dominated by polychaetes (94 taxa), molluscs (70 taxa) and crustaceans (45 taxa). Species composition varied with reef size, although reefs greater than 25 cm width exhibited relatively little variation. In comparison with other biogenic polychaete habitats, S. vermicularis reefs appear to support a highly diverse community, which exhibits a high degree of similarity with that found in association with aggregations of the horse mussel, Modiolus modiolus. The presence of the Connemara clingfish, Lepadogaster candollei, rarely recorded at such a northerly latitude, on several reefs, indicates that the reef habitat may provide a stronghold for this species at the edge of its biogeographical range.
‘Pliocardia' krylovata, a new species of vesicomyid clam from cold seeps along the Costa Rica Margin
Authors: Martin Alanna M. , Goffredi Shana K.
Published: July 2011

‘Pliocardia' krylovata, sp. nov. (Bivalvia: Vesicomyidae: Pliocardiinae) is described from cold seeps off the coast of the Nicoya Peninsula, Costa Rica (700–1000 m depth). The phylogenetic position of‘P.' krylovatawas assessed by both morphological comparisons as well as nucleotide data from the cytochrome c oxidase I gene. Within the vesicomyids,‘P.' krylovatabelongs to the Pliocardiinae and its closest relative is‘Calyptogena' ponderosa, which also bears some morphological resemblance to the genusPliocardia, perhaps suggesting a need for reanalysis of not only its generic designation, but also the entire Pliocardiinae subfamily.‘P.' krylovatahas morphological similarities to‘Pliocardia' bowdenianaand‘Vesicomya' crenulomarginata, recently reassigned to the genusPliocardia, including a thick shell, obvious rostrum, pointed posterior end, and a sculptured shell with concentric ribs on the outer surface, to name a few. It is morphologically distinguished, however, by having a complex pallial sinus and remarkably deep escutcheon.
Beaked whale strandings on the Falkland Islands and South Georgia, South Atlantic Ocean, between 1866 and 2008
Authors: Otley Helen , Smith John , Dalebout Merel L.
Published: July 2011

Records of beaked whales stranded in the Falkland Islands and at South Georgia were collated for the period 1866 to 2008. Thirty-eight records, involving at least seven species in four genera, were documented. Strap-toothed whales (Mesoplodon layardiiGray, 1865) were the most common species with 11 records, including two neonates. Andrews' beaked whales (M. bowdoiniAndrews, 1908), Arnoux's beaked whales (Berardius arnuxiiDuvernoy, 1851), Cuvier's beaked whales (Ziphius cavirostrisGray, 1823), Gray's beaked whale (M. grayivan Haast, 1876), Hector's beaked whales (M. hectoriGray, 1871) and southern bottlenose whales (Hyperoodon planifronsFlower, 1882) were recorded on three to five occasions. In several cases, records suggested potential temporal changes in range. For example, Arnoux's beaked whale has not been recorded in the Falkland Islands since 1965, whilst Gray's beaked whale was not recorded prior to 1981, and Andrews' beaked whale was not recorded before 1987. Although the number of records for each species is low, this could reflect changes in water temperatures and/or prey availability. Overall, this study confirms that the Falkland Islands–Tierra del Fuego region is one of the world's key areas for beaked whales.
Vessel traffic affects bottlenose dolphin (Tursiops truncatus) behaviour in waters surrounding Lampedusa Island, south Italy
Authors: Papale Elena , Azzolin Marta , Giacoma Cristina
Published: July 2011

Since 2003, as part of the LIFE project ‘Del.Ta.’ (NAT/IT/000163) a bottlenose dolphin community has been studied in order to assess the impact of increasing boat traffic in the Pelagie Archipelago (Sicily, Italy). During the summer of 2006 and 2008, land-based surveys were carried out at Lampedusa, one of the Archipelago's Islands, at set hours from 6 locations (7 in 2008) in standard weather conditions. Continuous horizon scanning and focal group sampling methods were used to study dolphin presence and behaviour. Dolphin–boat interactions were recorded for each sighting. A total of approximately 559 hours were spent monitoring and 83 sightings were recorded. With regard to the different types of vessels, interaction with sailing boats was always neutral, whereas fast boats caused the interruption of all activities and avoidance behaviour. Positive interaction occasionally occurred with bottom trawling fishing boats. Interactions recorded when fishing and powered engine boats approached within 200 m predominantly resulted in a negative reaction from the dolphins (approximately 70%) and dolphin behaviour was affected in terms of occurrence and patterns. Behavioural analysis showed that the animals reduced the frequency of behaviours related to feeding, social and relaxing activities. The dolphins also increased information-gathering behaviour such as spyhopping. The use of Markovian chain models revealed evidence of disruptions in sub-sequences made up of behaviours often associated with feeding. After boat departures, the animals rarely restarted their previous activity and persistence of this effect could have long-term consequences as a result of non-habituation. Sighting duration also decreased in the presence of vessels. The possible negative long-term effect of the presence of boats may be indicated by the lower mean sighting duration in 2008, when the highest presence of powered engine boats was recorded. In view of the scenario outlined above, local authorities need to enforce the requirement of maintaining a distance of over 200 m away from the animals for all types of boat and also promote regular land-based surveys of vessel impacts for tourist boats and dolphin watching cruises.