bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication of segmented cladding fiber by bicomponent spinning
Authors: Duan Julan , Teng Cuiqing , Han Keqing , Yu Muhuo , Wu Wenxuan , Zhang Qijin , Chiang Kin Seng
Published: June 2009

Fabrication of segmented cladding fiber (SCF) by bicomponent spinning was proposed in this article. In the new designed spin pack, we considered the high refractive component of cladding and core as a whole to control the cross section of the fiber. Quenching system in current bicomponent melting spinning system was modified according to the requirement of quenching fiber with a large size. The polymer SCF with required cross section was successfully fabricated using polycarbonate and polymethyl methacrylate. The transmission loss in the wavelength of 500–1000 nm was tested by the cut‐back method. The result showed that the transmission loss of the obtained fiber was comparatively high, being up to 30 dB/m. The output light pattern of the obtained fiber of 60 cm was collected by using a charge‐coupled device camera with laser light of 532 nm as the input. The output light pattern for the far field was a uniform circle and that for the near field was similar to the cross‐section designed. The results showed that the obtained fiber was still a multimode optical fiber because of the comparatively large refractive index difference between the two materials used. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Effect of steady shear on the morphology of biodegradable poly(ϵ‐caprolactone)/polylactide blend
Authors: Zhang Yisheng , Wu Defeng , Zhang Ming , Zhou Weidong , Xu Chenchen
Published: June 2009

The biodegradable polymer blend containing 70/30 weight ratio of poly(ε‐caprolactone) (PCL) and polylactide (PLA) was prepared by means of melt mixing. The evolution of the “sea‐island” phase structure in the steady shear flow was studied using scanning electron microscope (SEM) and parallel‐plate rheometer. The results show that the morphological evolution induced by steady shear follows different mechanisms at various flow rates. The lower shear rates (Newtonian flow) promote coalescence of the discrete PLA droplets, whereas higher shear rates (non‐Newtonian flow) promote break‐up of the droplets. The dynamic rheological responses of PCL/PLA blend before and after steady preshear were then analyzed using emulsion model and Taylor equation. The results show that the evolution approaches of the morphology highly depend on changed level of the critical effective interfacial tension in the steady shear flow, which are further confirmed by the transient rheological measurements. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Synthesis and rational design of anti‐inflammatory compounds: N‐phenyl‐cyclohexenyl sulfonamide derivatives
Authors: Lloret Gustavo R. , Cunha Neto Álvaro , Rittner Roberto , Bitencourt Michelle , Freitas Matheus P. , Aquino Nilton S.
Published: June 2009

The synthesis of (±)‐ethyl 6‐[N‐(2‐chloro‐4‐fluorophenyl)sulfamoyl]cyclohex‐1‐ene‐1‐carboxylate (5n) has been reproduced from a method previously described and served as the background for the preparation of a nitro derivative, potentially useful as an anti‐inflammatory agent. Furthermore, a structure‐based QSAR analysis of a series of N‐arylsulfamoyl congeners derived a highly predictive model for the activities of novel small‐molecule inhibitors of NO and cytokine production, whose preparation may be successfully achieved according to a similar procedure as above. Copyright © 2009 John Wiley & Sons, Ltd.
Pulsed‐Plasma Polymeric Allylamine Thin Films
Authors: Yang Zhilu , Wang Xiaona , Wang Jin , Yao Ye , Sun Hong , Huang Nan
Published: June 2009

High surface functional groups concentration, excellent dynamical stability and mechanical properties are ideal for biomedical plasma polymers. Herein, we report a simple and effective approach to fabricating such an ideal plasma polymeric allylamine film on 316L stainless steel (SS) by pulsed plasma polymerization. The experimental results show that the concentration of the primary amine groups (NH2/C) of the plasma polymeric allylamine film was 2.4 ± 0.4%. The plasma polymeric allylamine film possesses not only high surface NH2 concentration, but also high cross‐linking degree and close‐knit network structure that could well resist hydrolysis, and dissolution in the aqueous solution. Furthermore, the plasma polymeric allylamine film was used as a stent coating that shows a good resistance to the deformation behaviour of compression and expansion of the stent.

magnified image
Characterising relict cryogenic macrostructures in mid‐latitude areas of the USA with three‐dimensional ground‐penetrating radar
Authors: Doolittle James , Nelson Frederick
Published: June 2009

Ground‐penetrating radar (GPR) has considerable potential for the detection and identification of sediment‐filled wedges and relict polygonal patterns in mid‐latitude areas. Relict cryogenic macrostructures have been described previously both within and outside the maximum extent of the Late Wisconsinan glacial border in many regions of the USA. The features were formed under climatic conditions associated with permafrost and periglacial conditions and provide evidence of climate change. In this study, buried relict cryogenic macrostructures were identified with GPR. On some two‐dimensional GPR (2D GPR) records, boundaries with the host materials are indistinguishable or blurred resulting in the features being overlooked, misinterpreted and/or imprecisely delineated. Three‐dimensional GPR (3D GPR) was able to delineate buried networks of sediment‐filled wedges and provided more meaningful information than 2D radar records. When supplemented with adequate ground‐truth observations, GPR offers considerable potential for imaging, interpreting and mapping near‐surface cryogenic macrostructures in former periglacial environments. Copyright © 2009 John Wiley & Sons, Ltd.
Confined dynamics of a ribosome‐bound nascent globin: Cone angle analysis of fluorescence depolarization decays in the presence of two local motions
Authors: Ellis Jamie P. , Culviner Peter H. , Cavagnero Silvia
Published: June 2009

We still know very little about how proteins achieve their native three‐dimensional structure in vitro and in the cell. Folding studies as proteins emerge from the mega Dalton‐sized ribosome pose special challenges due to the large size and complicated nature of the ribosome‐nascent chain complex. This work introduces a combination of three‐component analysis of fluorescence depolarization decays (including the presence of two local motions) and in‐cone analysis of diffusive local dynamics to investigate the spatial constraints experienced by a protein emerging from the ribosomal tunnel. We focus on E. coli ribosomes and an all‐α‐helical nascent globin in the presence and absence of the cotranslationally active chaperones DnaK and trigger factor. The data provide insights on the dynamic nature and structural plasticity of ribosome‐nascent chain complexes. We find that the sub‐ns motions of the N‐terminal fluorophore, reporting on the globin dynamics in the vicinity of the N terminus, are highly constrained both inside and outside the ribosomal tunnel, resulting in high‐order parameters (>0.85) and small cone semiangles (<30°). The shorter globin chains buried inside the tunnel are less spatially constrained than those of a reference sequence from a natively unfolded protein, suggesting either that the two nascent chain sequences have a different secondary structure and therefore sample different regions of the tunnel or that the tunnel undergoes local structural adjustments to accommodate the globin sequence. Longer globins emerging out of the ribosomal tunnel are also found to have highly spatially constrained slow (ns) motions. There are no observable spectroscopic changes in the absence of bound chaperones.
Virulence development and genetic polymorphism in Meloidogyne incognita (Kofoid & White) Chitwood after prolonged exposure to sublethal concentrations of nematicides and continuous growing of resistant tomato cultivars
Authors: Meher Hari C , Gajbhiye Vijay T , Chawla Gautam , Singh Ghanendra
Published: June 2009

BACKGROUND: The root‐knot nematode, Meloidogyne incognita (Kofoid & White) Chitwood, is an important plant pathogen damaging to tomato. Continuous use of resistant tomato cultivars and nematicides for its effective management might lead to resistance break‐up or nematicide failure. Genetic variability and virulence in M. incognita on susceptible Pusa Ruby tomato were analysed by bioassay, esterase and DNA polymorphism after a 5 year weekly exposure to carbofuran, carbosulfan, cadusafos and triazophos at 0.0125, 0.0250 and 0.0500 µg g−1. Virulence in M. incognita after a 5 year multiplication on resistant tomatoes was assessed.

RESULTS: The nematicidal treatments resulted in the development of virulent M. incognita populations. Their invasion potential increased significantly after continuous exposure to low concentrations of the nematicides. Also, growing resistant tomato cultivars for ten successive seasons resulted in a 6.6% increase in the invasion potential. These virulent populations exhibited 1–3 additional esterase and DNA bands compared with untreated populations.

CONCLUSION: A 5 year exposure of M. incognita to sublethal concentrations of nematicides or resistant tomato cultivars exerted enough selection pressure to cause genomic alterations for virulence development. Isozyme markers can be used for rapid and precise diagnostics of field populations by advisory services, enabling judicious remedial management decisions. Copyright © 2009 Society of Chemical Industry
A synchrotron tensile test setup for nanocrystalline thin films
Authors: Ulyanenkova T. , Baumbusch R. , Filatova T. , Doyle S. , Castrup A. , Gruber P. A. , Markmann J. , Weissmüller J. , Baumbach T. , Hahn H. , Kraft O.
Published: June 2009

The current report covers the establishment of an in situ X‐ray diffraction tensile experiment at the synchrotron ANKA located at Forschungszentrum Karlsruhe for probing diffraction signals from nanocrystalline thin films during tensile deformation. Measurements on nanocrystalline palladium films verify the capabilities of the setup.
Optically stimulated luminescence at room temperature of hydrothermal K2YF5:Pr3+ crystals
Authors: Marcazzó J. , Khaidukov N. M. , Caselli E. , Dangelo C. , Santiago M.
Published: June 2009

In this paper optically stimulated luminescence (OSL) properties of Pr3+‐doped double potassium yttrium fluoride (K2YF5) under green light stimulation at room temperature as a function of the doping concentration are reported. Besides, some characteristics concerning the possible application of this composition as a new OSL dosimeter are presented, namely, the dose–response and fading of the OSL signal. The residual thermoluminescence (TL) response of K2YF5:Pr3+ after the OSL experiment has been investigated in order to establish whether the traps responsible for OSL are also involved in the TL process. Spectral analysis of the OSL emission has been carried out to determine the role played by Pr3+ ions in the radiative relaxation process. Finally, the total OSL output of K2YF5:Pr3+ is compared to that of commercial Al2O3:C.
Transport and recombination kinetics in TlGaTe2 crystals
Authors: Qasrawi A. F. , Gasanly N. M.
Published: June 2009

In this work, the transport and recombination mechanisms as well as the average hole‐relaxation time in TlGaTe2 have been investigated by means of temperature‐dependent dark electrical conductivity, photoexcitation intensity‐dependent photoconductivity, and Hall effect measurements, respectively. The experimental data analysis revealed the existence of a critical temperature of 150 K. At this temperature, the transport mechanism is disturbed. The dark conductivity data analysis allowed the determination of an energy state of 258 meV. The hole‐relaxation time that was determined from the Hall mobility data was observed to increase with decreasing temperature. The behavior was attributed to the hole–thermal lattice scattering interactions. At fixed photoexcitation intensity, the photocurrent Iph decreases with decreasing temperature down to 150 K. Below this temperature it changes direction. The latter data allowed the determination of the recombination center energy as 110 meV. On the other hand, at fixed temperature and variable illumination intensity, the photocurrent follows the relation IphαFn (the value of the exponent, n, decreases with decreasing temperature).
Different roles of cadmium‐ and sulfur (selenium)‐terminated crystal facets in the formation of a photovoltaic response from hybrid organic/inorganic CdS (CdSe) heterojunctions
Authors: Dimitriev O. P. , Kislyuk V. V. , Syngaevsky A. F. , Smertenko P. S. , Pud A. A.
Published: June 2009

Photovoltaic (PV) response of hybrid organic/inorganic bilayer heterostructures based on organic polymers or small molecules on the one hand, such as poly(3‐hexylthiophene), polyaniline doped with poly(styrenesulfonic acid), poly(ethylene‐3,4‐dioxythiophene) doped with poly(styrenesulfonic acid) (PEDOT:PSS), phthalocyanine, and inorganic CdS or CdSe single crystals on the other hand, has been studied depending on the crystal facet used. The effect of the surface‐terminated layer of the crystal on the PV performance of hybrid heterojunctions has been observed. It was found that the different crystal facets could render both quantitative and qualitative effect on PV properties of the hybrid heterojunctions.

Photocurrent spectra of CdS/PEDOT:PSS heterojunctions based on the Cd‐terminated (solid curve) and S‐terminated (dashed curve) crystal facet.

magnified image
Raman tensor analysis of sapphire single crystal and its application to define crystallographic orientation in polycrystalline alumina
Authors: Munisso Maria Chiara , Zhu Wenliang , Pezzotti Giuseppe
Published: June 2009

Raman selection rules were theoretically put forward and, according to the obtained relationships, the full set of Raman tensor elements was experimentally determined for the corundum structure of a sapphire single‐crystal. The knowledge of the Raman selection rules allowed us to represent the change in polarizability of the aluminium oxide molecule with respect to each of the available vibrational modes. Restrictions related to the symmetry of the scattering system are also discussed together with directional properties, thus leading to unambiguous assignment of the fundamental modes available in sapphire single‐crystal. From the experimental side, scattering intensities of Raman bands located at 378 cm–1and 417 cm–1, which correspond to theEgand theA1gphonon modes of the corundum structure, respectively, were collected in selected polarization configurations as a function of in‐plane rotation angle on different crystallographic planes. Fitting to theoretical equations (i.e., worked out for different crystallographic orientations) enabled us to unequivocally define the elements of the Raman tensor. Finally, a tensorial algorithm was proposed for the practical determination of unknown crystallographic textures in polycrystalline alumina materials, an issue of significant importance in materials science. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
How the SiC substrate impacts graphene's atomic and electronic structure
Authors: Magaud L. , Hiebel F. , Varchon F. , Mallet P. , Veuillen J.‐Y.
Published: June 2009

Graphene, the two‐dimensional form of carbon presents outstanding electronic and transport properties. This gives hope for the development of applications in nanoelectronics. However, for industrial purpose, graphene has to be supported by a substrate. We focus here on the graphene‐on‐SiC system to discuss how the SiC substrate interacts with the graphene layer and to show the effect of the interface on graphene atomic and electronic structures.

magnified image

Figure shows cross section of the ab initio total charge density at the graphene/C‐terminated SiC interface.

(© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonparametric equivalence testing with respect to the median difference
Authors: Meier Ulrich
Published: June 2009

The problem of comparing two independent groups of univariate data in the sense of testing for equivalence is considered for a fully nonparametric setting. The distribution of the data within each group may be a mixture of both a continuous and a discrete component, and no assumptions are made regarding the way in which the distributions of the two groups of data may differ from each other – in particular, the assumption of a shift model is avoided. The proposed equivalence testing procedure for this scenario refers to the median of the independent difference distribution, i.e. to the median of the differences between independent observations from the test group and the reference group, respectively. The procedure provides an asymptotic equivalence test, which is symmetric with respect to the roles of ‘test’ and ‘reference’. It can be described either as a two‐one‐sided‐tests (TOST) approach, or equivalently as a confidence interval inclusion rule. A one‐sided variant of the approach can be applied analogously to non‐inferiority testing problems. The procedure may be generalised to equivalence testing with respect to quantiles other than the median, and is closely related to tolerance interval type inference. Copyright © 2009 John Wiley & Sons, Ltd.
The direct assimilation of cloud‐affected satellite infrared radiances in the ECMWF 4D‐Var
Authors: McNally A. P.
Published: June 2009

A system has been developed to make use of infrared radiance data in cloudy conditions. The central strategy is to extend the 4D‐Var analysis control vector to include parameters which describe the cloud conditions and simultaneously estimate these parameters together with temperature and humidity inside the main analysis. In the current prototype configuration of the system, the extra cloud variables are decoupled from the model physics and only cloudy data in completely overcast conditions are used. Early experiments with the new system have produced some encouraging results. Additional use of overcast radiance data improves the analysis fit to independent radiosonde observations and results in some small, but statistically significant, improvements in forecast quality. Copyright © 2009 Royal Meteorological Society
All‐subsets regression under effect heredity restrictions for experimental designs with complex aliasing
Authors: Hamada Christina A. , Hamada Michael S.
Published: June 2009

We consider an all‐subsets regression method for models under effect heredity restrictions for experimental designs with complex aliasing, whose number of potential main effects and two‐factor interactions exceed the number of runs. In this paper, we present an algorithm that systematically attempts to fit all such models. We illustrate the algorithm with two published experiments. Copyright © 2009 John Wiley & Sons, Ltd.
Analysis of Relationships Between Structure, Surface Properties, and Antimicrobial Activity of Quaternary Ammonium Chlorides
Authors: Krysiński Jerzy , Płaczek Jakub , Skrzypczak Andrzej , Błaszczak Jan , Prędki Bartłomiej
Published: June 2009

The research concerns analysis of cause‐effect relationships occurring between condition attributes describing structure and surface‐active properties and decision attributes (antimicrobial activity) of alkyl(alkylthiomethyl)dimethylammonium chlorides and alkyl(alkoxymethyl)dimethylammonium chlorides. 72 ammonium chlorides were described by 7 condition attributes concerning structure and 7 condition attributes concerning surface‐active properties. Antimicrobial activity was expressed by minimal inhibitory concentration (MIC) against strains of Pseudomonas aeruginosa ATCC 15442 (classification I) and Candida albicans ATCC 10231 (classification II). The ROSE 2 (Rough Sets Data Explorer) and LEM 2 (Minimal Set Covering Algorithm) software were used to perform the analysis. Attributes with continuous values were discretized. 45 decision rules were generated in the classification I, and 38 rules in the classification II. Those described the most important dependencies between structure, surface‐active properties of analyzed chlorides and their antimicrobial activity. Strong decision rules supported by large number of objects provide guidelines which may facilitate synthesis of new compounds with preferable antimicrobial properties.
The QSAR Modeling of Cytotoxicity on Anthraquinones
Authors: Takkis Kalev , Sild Sulev , Maran Uko
Published: June 2009

A QSAR analysis was carried out on a dataset of 126 anthraquinone‐based cytotoxic compounds. A PCA of the molecular descriptors was used to cluster the dataset into smaller subsets according to their structural features and QSAR models were derived for the selected sets. During the modeling, protonated states of molecules and nonlinear transformations of the descriptors were considered. The developed models have been interpreted in the context of cytotoxicity and validated with leave‐one‐out, and leave‐many‐out cross‐validation. The descriptors in the resulting models describe the size and charge distribution of molecules although in different clusters their proportions vary.
Reduced vdW Radius Improves Site of Metabolism Predictions Using X‐Ray Structure of CYP2D6
Authors: Prusis Peteris , Afzelius Lovisa
Published: June 2009

The major oxidative metabolic degradation of drugs occurs through cytochrome P450 enzymes, which has very wide substrate specificity. Therefore it is crucial to be able to determine the exact position for enzymatic oxidation. Several methods have been developed for site of metabolism (SOM) prediction in silico, including docking based methods. One of the benefits of docking based methods is that it visualizes the drug‐enzyme complex and facilitate antidesign towards specific interactions. Recently, the crystal structure of one of the cytochrome P450 enzyme isoforms, CYP2D6, has been published. Here we investigate the feasibility to utilize this structure for SOM predictions using docking. It was found that the intact structure was not well suited for SOM predictions. Reduction of vdW radius of enzyme atoms in the docking grid significantly improved predictions, indicating that the atoms of some of the sidechains of the solved CYP2D6 crystal structure conformation interfere with docked ligands atoms, thus, preventing accurate dockings and SOM predictions.
NMR spin–spin coupling constants and hyperconjugative interactions
Authors: Contreras R. H. , Suardíaz R. , Pérez C. , Crespo‐Otero R. , San Fabián J. , de la Vega J. M. García
Published: June 2009

The potential of NMR spin–spin coupling constants as probes to study fine details of electronic molecular structures is briefly discussed in this work through two different examples. A qualitative analysis of the polarization propagator expression for the Fermi contact term is applied for predicting factors affecting 1JCH, and comments are made about how to generalize those results to different types of one‐bond spin‐spin couplings. Moreover, the Natural J Coupling method is applied to get insight into electronic factors defining a Karplus relationship of type 3JHH(180°) < 3JHH(0°) known in the literature for some amino acids. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Switching contact task control in hydraulic actuators: Stability analysis and experimental evaluation
Authors: Sekhavat P. , Wu Q. , Sepehri N.
Published: June 2009

A switching contact task control for hydraulic actuators is proposed. The controller is built upon three individually designed control laws for three phases of motion: (1) position regulation in free space, (2) impact suppression and stable transition from free to constrained motion and (3) force regulation in sustained‐contact motion. The position and force control schemes are capable of asymptotic set‐point regulation in the presence of actuator friction and without the complexity of sliding mode or adaptive control techniques. The intermediate impact control scheme is included for the first time to dampen the undesirable impacts and dissipate the impact energy that could potentially drive the whole system unstable. The solution concept and the stability of the complete switching control system are analyzed rigorously using the Filippov's solution concept and the concept of Lyapunov exponents. Both computer simulations and experiments are carried out to demonstrate the efficacy of the designed switching control law. Copyright © 2009 John Wiley & Sons, Ltd.
H∞ filtering for singular Markovian jump systems with time delay
Authors: Wu Zhengguang , Su Hongye , Chu Jian
Published: June 2009

The problem of H∞ filtering is considered for singular Markovian jump systems with time delay. In terms of linear matrix inequality (LMI) approach, a delay‐dependent bounded real lemma (BRL) is proposed for the considered system to be stochastically admissible while achieving the prescribed H∞ performance condition. Based on the BRL and under partial knowledge of the jump rates of the Markov process, both delay‐dependent and delay‐independent sufficient conditions that guarantee the existence of the desired filter are presented. The explicit expression of the desired filter gains is also characterized by solving a set of strict LMIs. Some numerical examples are given to demonstrate the effectiveness of the proposed methods. Copyright © 2009 John Wiley & Sons, Ltd.
Beyond species richness: Expanding biodiversity–ecosystem functioning theory in detritus‐based streams
Authors: Kominoski J. S. , Hoellein T. J. , Leroy C. J. , Pringle C. M. , Swan C. M.
Published: June 2009

Initial research informing biodiversity–ecosystem functioning (B–EF) theory focused largely on terrestrial plant species richness effects on productivity. Recent studies in stream ecosystems have further advanced understanding of B–EF beyond species richness by testing effects of species diversity (richness and composition) at multiple trophic levels. Recent meta‐analyses of stream B–EF studies across multiple trophic levels found stronger evidence for composition‐ than richness‐functioning relationships. Here, we further examine effects of resource and consumer diversity on stream organic matter processing (OMP) to identify general patterns and potential mechanisms of non‐additivity across spatial and temporal heterogeneity. We also review multi‐trophic consumer response patterns to resource diversity to assess how consumer diversityresponsescompare to independent resource and consumereffectson OMP in streams. Consistent emergent patterns include: (1) Top‐down (i.e. consumer) diversity effects are common among vertebrate, invertebrate and microbial trophic levels and are generally explained by species evenness; (2) bottom‐up (i.e. resource) diversity effects are mediated by species evenness and vary both spatially and temporally and (3) consumer responses to resource diversity that best explain resource diversity effects are predominantly seen at the microbial level. Resource and consumer diversity effects are driven by dominance of functionally distinct taxa. However, response of consumers to resource diversity only partially explain resource diversity effects, suggesting functional differences between how naturally colonizing and manipulated consumer assemblages use OM resources. The challenges facing general ecology and the advancement of B–EF theory include an improved understanding of how environmental heterogeneity and temporal and spatial variation influence B–EF patterns. Copyright © 2009 John Wiley & Sons, Ltd.
Secondary production as part of bioenergetic theory—contributions from freshwater benthic science
Authors: Benke Arthur C.
Published: June 2009

Bioenergetics and energy flow studies have played a prominent role in ecology since the time of Raymond Lindeman's classic paper. Several early seminal studies, including Lindeman's, were on freshwater ecosystems, all of which included benthic secondary production as an important element. Independently of these energy flow studies, benthic ecologists have played a major role in developing the methods of population‐based secondary production, and produced the majority of all secondary production studies in ecology. These studies have not only contributed to our understanding of the importance of animals in ecosystem energy flow, but production is now used to address a wide variety of ecological questions from the construction of quantitative food webs, to examining predator‐prey relationships, to experimental studies of food resource use, to assessing the effects of nonnative species, pollution and catchment land‐use change. Unfortunately, appreciation of the utility of secondary production is largely restricted to aquatic ecologists, particularly those working in freshwater and marine benthic habitats. Further, treatment of secondary production is very limited in most general ecology texts. Continued use of secondary production to address a diversity of ecological questions should result in a greater appreciation of its advantages and cause it to become better known in the broader ecological community. Copyright © 2009 John Wiley & Sons, Ltd.
PCM: a privacy‐preserving detection mechanism in mobilead hocnetworks
Authors: Zhu Bo , Ren Kui , Wang Lingyu , Debbabi Mourad
Published: June 2009

Although extensive research work has been undertaken to secure mobilead hocnetworks, till recently, researchers began to pay attention to the anonymity issue, and this issue was investigated mainly in terms of secure routing and data forwarding. We indicate that, in mobilead hocnetworks, there is an increasing interest in providing anonymity for the witnesses, i.e., those users who share their knowledge in detecting either malicious or selfish users. On the other hand, it is also a challenging problem to prevent the misuse of anonymous sources. In this paper, we propose thePlainClothesMan(PCM) protocol to provide anonymity for the witness who helps identify malicious or selfish users. Once there are more than a certain number of claims from distinct users against the same user, she is identified as a malicious or selfish user. Moreover, in PCM, the misuse of the witness anonymity is prevented in such a way that any malicious user who broadcasts multiple invalid claims against the same user for the same reason can be identified. Two exemplary scenarios are designed and simulated to model the necessities of witness anonymity in mobilead hocnetworks. Simulation results show that witness anonymity is very important for ensuring proper and efficient executions of fundamental functionalities of mobilead hocnetworks, e.g., certificate revocation and fairness, and PCM is both effective and efficient in providing such a type of anonymity. Copyright © 2009 John Wiley & Sons, Ltd.
An efficient random key distribution scheme for large‐scale distributed sensor networks
Authors: Das Ashok Kumar
Published: June 2009

Key establishment in sensor networks is a challenging problem because of resource constraints of the sensors. Due to resource limitations and vulnerable to physical capture of the sensor nodes, the classical public‐key routines are impractical in most sensor network architectures. In this paper, we propose a new random key pre‐distribution scheme. Our scheme always defines a relationship between the ids of neighbor nodes and the keys possessed by those nodes while maintaining the required randomness in choice of keys. Our proposed scheme provides better security against node capture attack than the existing random key pre‐distribution schemes. Moreover, it has better trade‐off between communication overhead, network connectivity and security against node capture compared to the existing random key pre‐distribution schemes. In addition, it supports dynamic node addition efficiently after initial deployment of the nodes in the network. Copyright © 2009 John Wiley & Sons, Ltd.
Possibility of Thermal Protection in Earth Re‐entry Flight by MHD Flow Control with Air‐Core Circular Magnet
Authors: Yoshino Tomoyuki , Fujino Takayasu , Ishikawa Motoo
Published: June 2009

The possibility of thermal protection in an earth re‐entry flight by the magnetohydrodynamic (MHD) flow control with an air‐core circular magnet producing about 1 T or less on the wall surface of a space vehicle is examined by r‐z two‐dimensional numerical simulations. The present study adopts a hemisphere with a radius of 1.0 m as the nose shape of a space vehicle. The numerical results show that aerodynamic heating can be reduced by the MHD flow control with an air‐core circular magnet, and also that the maximum wall heat flux and the effect of the MHD flow control become prominent with the magnitude of coil current and the flight altitude. Furthermore, it is found that there is an optimum magnet size to maximize the effect of MHD flow control under constant exciting magnetic energy, and also the optimum size gets reduced with the decrease in the flight altitude. © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
A New Idea Monitoring Concentration and Liquid‐Level of Electrolytic Solution
Authors: Lu Gui‐Rong , He Bao‐Xiang , Chu Kai‐Bin
Published: June 2009

A new idea of measurement for the liquid‐level and the concentration of the electrolytic solution using a single sensor at the same time is presented. A multi‐functional sensor with novel structure for achieving this proposed new idea is designed. Two sensing functions, namely, the capacitance and the inductance sensing functions can be realized by this sensor. Unknown concentration and liquid‐level of the electrolytic solution in a single tank are estimated in this paper. © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Cesarean scar defect: correlation between Cesarean section number, defect size, clinical symptoms and uterine position
Authors: Wang C.‐B. , Chiu W.‐W.‐C. , Lee C.‐Y. , Sun Y.‐L. , Lin Y.‐H. , Tseng C.‐J.
Published: June 2009

Objectives

To determine the prevalence of clinical symptoms associated with Cesarean scar defects, and to determine the association between the size of these defects, clinical complaints, uterine position, and a history of multiple Cesarean sections.

Methods

In this cross‐sectional study, Cesarean scar defects in women with a history of transverse lower‐segment Cesarean section were measured by transvaginal ultrasound while being assessed for other gynecological conditions. The relationships between the size of the Cesarean scar defect and the clinical symptoms, uterine position and number of previous Cesarean sections were evaluated. Patients with other uterine pathologies, including endometrial hyperplasia, polyps, malignancy and submucosal myomas, were excluded from the study.

Results

During a 3‐year period, 4250 women were assessed by transvaginal sonography, of whom 293 (6.9%) were diagnosed with Cesarean scar defects. Eighty‐six patients were excluded due to other uterine pathologies. Altogether, 207 patients with Cesarean scar defects were included in this study. Women who had undergone multiple Cesarean sections tended to have larger scar defects (in width and depth) than did those who had undergone a single Cesarean section. Women with retroflexed uteri also tended to have wider defects than those with anteflexed uteri. Defect width was significantly greater in women with postmenstrual spotting, dysmenorrhea and chronic pelvic pain.

Conclusions

Multiple Cesarean sections and retroflexed uteri are risk factors for larger Cesarean scar defects. The size of the Cesarean scar defect is associated with clinical symptoms such as postmenstrual spotting, dysmenorrhea and chronic pelvic pain. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Three‐dimensional ultrasound detection of abnormally located intrauterine contraceptive devices which are a source of pelvic pain and abnormal bleeding
Authors: Benacerraf B. R. , Shipp T. D. , Bromley B.
Published: June 2009

Objective

To determine whether intrauterine contraceptive devices (IUDs) that are located abnormally within the myometrium or cervix cause a higher incidence of pelvic pain and abnormal bleeding compared with normally positioned devices.

Methods

Over a period of 9 months, all patients with an IUD presenting at our unit for two‐dimensional pelvic ultrasound underwent a three‐dimensional (3D) volume reconstruction of the coronal view, to visualize the entire IUD within the cavity. The IUD was deemed malpositioned if any part extended past the cavity, into the myometrium or cervix. The indications for ultrasound were recorded at presentation for the exam. The presenting symptoms of patients with an abnormally located IUD were compared with those with normally positioned ones.

Results

Among 167 consecutive patients with an IUD evaluated using the 3D reconstructed coronal view, 28 (16.8%) had an IUD with side arms abnormally located within the myometrium. The abnormal positioning of the IUD arms was only detected using the 3D coronal view. A higher proportion of patients with an abnormally located IUD presented with bleeding (35.7%) or pain (39.3%) compared with those with normally positioned IUDs (15.1% with bleeding and 19.4% with pain) (P = 0.02 and 0.03, respectively). Seventy‐five percent of patients with an abnormally located IUD presented with bleeding or pain compared with 34.5% of those whose IUD was normally placed (P = 0.0001). Twenty of 21 patients with an abnormally located IUD presenting with pelvic pain or bleeding reported improvement in their symptoms after IUD removal.

Conclusion

A 3D coronal view of the uterus is useful in the visualization of IUDs. The coronal view showing the entire device and its position within the uterus may help in identifying the cause of pelvic pain and bleeding in patients with an embedded IUD. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Myocardial tissue Doppler assessment of diastolic function in the growth‐restricted fetus
Authors: Naujorks A. A. , Zielinsky P. , Beltrame P. A. , Castagna R. C. , Petracco R. , Busato A. , Nicoloso A. L. H. , Piccoli A. , Manica J. L.
Published: June 2009

Objectives

Myocardial tissue Doppler (MTD) is a technique for the measurement of myocardial velocities in systole and diastole. This study evaluates the use of MTD in the assessment of cardiac diastolic function in fetuses with intrauterine growth restriction (IUGR) with placental insufficiency and in appropriate‐for‐gestational age (AGA) fetuses with hypertensive mothers.

Methods

This study included 14 IUGR fetuses with placental insufficiency (Group 1), 13 AGA fetuses with hypertensive mothers (Group 2), and 29 AGA fetuses with healthy mothers (Group 3). Patients with other diseases were excluded. All fetuses had a gestational age of at least 25 weeks. MTD assessment was performed with the sample volume placed at the basal segment of the left ventricular side wall (LV), the interventricular septum (IVS) and the right ventricular free wall (RV). E′/A′ ratios were calculated for each location. Mitral and tricuspid flows were assessed by conventional spectral pulsed Doppler.

Results

Significant differences were found between groups for E′/A′ at the IVS (P < 0.001) and LV (P = 0.009), with a higher mean (± SD) value in Group 1 (IVS: 0.92 ± 0.28; LV: 0.85 ± 0.19) than in Groups 2 (IVS: 0.62 ± 0.09; LV: 0.68 ± 0.14) and 3 (IVS: 0.71 ± 0.14; LV: 0.69 ± 0.15). In the RV, there was no statistically significant difference in the E′/A′ ratio (P = 0.2). No differences were observed for mitral and tricuspid flow velocities and ratios.

Conclusions

Using MTD, the ratios between early and late diastolic myocardial velocities are higher in IUGR fetuses than in AGA fetuses at the IVS and the LV, regardless of the presence of maternal hypertension. MTD may be more sensitive than atrioventricular spectral Doppler for the detection of ventricular diastolic dysfunction in IUGR fetuses. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
The L2E method
Authors: Scott David W.
Published: June 2009

Estimation theory and practice is generally focused on maximum likelihood methodology, which boasts of claims of efficiency and widespread availability in software. Likelihood methods occasionally encounter problems with small sample sizes, or if the data are contaminated with outliers. The first problem can be addressed by regularization methods such as Bayesian estimation; the latter problem can be solved by using robust methodology such as the M‐estimator, for example. is a particular example of an M‐estimator. This article motivates its special properties and provides detailed examples that take advantage of those properties. Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Density Estimation
Accumulation of minor and trace elements in lichens in and around Kolkata, India: an application of X‐ray fluorescence technique to air pollution monitoring
Authors: Majumdar S. , Ram S. S. , Jana N. K. , Santra S. , Chakraborty A. , Sudarshan M.
Published: June 2009

A recent environmental survey has listed Kolkata, a megacity in Eastern India, as one of the most polluted cities in the world. Rapid urbanization and industrialization have resulted in an alarming increase in the level of air pollution in the city. Epiphytic lichens have extensively been used worldwide as bioindicators of environmental quality. They are very responsive to environmental stressors, especially gaseous pollutants and particulates including trace elements and heavy metals. This work describes application of energy dispersive X‐ray fluorescence, a fast multi‐elemental analytical technique, for estimating concentration of trace elements of lichen samples collected from sites in and around Kolkata. The results indicate that the samples from sites burdened with heavy vehicular load together with pollution from various industries and factories have significantly higher concentration of elements such as S, Ca, V, Cr, Mn, Fe, Ni and Pb as compared to those collected from sites having less or no load. Remarkable seasonal variation is also noted in the concentration of the elements such as Mn, Fe, Cu, Zn and Pb. Copyright © 2009 John Wiley & Sons, Ltd.
La3Br3Ni: Jahn–Teller Distortion in the Reduced Rare Earth Metal Halide
Authors: Zheng Chong , Mattausch Hansjürgen , Hoch Constantin , Simon Arndt
Published: June 2009

A ternary lanthanum bromide La3Br3Ni was synthesized from lanthanum, LaBr3 and nickel under argon at 800 °C. It crystallizes in the tetragonal space group I4122 (No. 98) with lattice constants a = 12.1758(9) Å and c = 11.744(2) Å. The structure is derived from the cubic Gd3I3C type of space group I4132 through a tetragonal distortion resulting in a squeezed nickel‐centered La6 octahedron. Electronic structure and bonding of the compound have been investigated.
Strukturen von polaren Magnesiumorganylen: Synthese und Struktur von Basen‐Addukten des Magnesiumindenids
Authors: Jaenschke Anja , Olbrich Falk , Behrens Ulrich
Published: June 2009

An improved X‐ray structure determination of magnesium indenide Mg(C9H7)2 (1) at low temperature was carried out. Four donor‐acceptor complexes of Mg(C9H7)2 (1) with O‐ and N‐donor Lewis bases were synthesized and characterized by X‐ray structure analysis. With dioxane and tetramethylethylenediamine (TMEDA) two simple monomeric complexes, [Mg(C9H7)2(dioxane)2]·1.5dioxane (2a) and [Mg(C9H7)2(TMEDA)] (3), were formed. With the O‐donors tetrahydrofuran (THF) and dimethylsulfoxide (DMSO) two ionic magnesium compounds 4 and 5 could be synthesized which have a [MgL6]2+ cation [L = THF and DMSO] and two uncoordinated indenide anions.
Invasive Aspergillosis of the Hand Caused by Aspergillus Ustus: A Case Report
Authors: Olorunnipa Olushola , Zhang Andrew Y. , Curtin Catherine M.
Published: June 2009

This is a case report of a 61-year-old cardiac transplant patient who developed a disseminated infection involving the upper extremity with a rare fungus known as Aspergillus ustus. The patient was successfully treated with aggressive serial debridements, antifungal medications, and reduction of immunosuppression. With these interventions, the patient avoided amputation despite the aggressive nature of this infection.
Effect of Cationic Surfactant Head Groups on Synthesis, Growth and Agglomeration Behavior of ZnS Nanoparticles
Authors: Mehta S. K. , Kumar Sanjay , Chaudhary Savita , Bhasin K. K.
Published: June 2009

Colloidal nanodispersions of ZnS have been prepared using aqueous micellar solution of two cationic surfactants of trimethylammonium/pyridinium series with different head groups i.e., cetyltrimethylammonium chloride (CTAC) and cetyltrimethylpyridinium chloride (CPyC). The role of these surfactants in controlling size, agglomeration behavior and photophysical properties of ZnS nanoparticles has been discussed. UV–visible spectroscopy has been carried out for determination of optical band gap and size of ZnS nanoparticles. Transmission electron microscopy and dynamic light scattering were used to measure sizes and size distribution of ZnS nanoparticles. Powder X-ray analysis (Powder XRD) reveals the cubic structure of nanocrystallite in powdered sample. The photoluminescence emission band exhibits red shift for ZnS nanoparticles in CTAC compared to those in CPyC. The aggregation behavior in two surfactants has been compared using turbidity measurements after redispersing the nanoparticles in water. In situ evolution and growth of ZnS nanoparticles in two different surfactants have been compared through time-dependent absorption behavior and UV irradiation studies. Electrical conductivity measurements reveal that CPyC micelles better stabilize the nanoparticles than that of CTAC.
Retrospective analysis of laparoscopic salpingostomy and conservative expectant management of tubal ectopic pregnancy
Authors: Takashima Kunitomo , Yoshida Hiroshi , Murase Mariko , Sato Aya , Sakakibara Hideya , Hirahara Fumiki , Ishikawa Masahiko
Published: June 2009

Purpose

To identify predictive factors for successful expectant management of ectopic pregnancy and to evaluate the prognosis for fertility after expectant management and laparoscopic salpingostomy.

Methods

Forty‐six cases of expectant management and eighty cases of laparoscopic salpingostomy for tubal ectopic pregnancy were retrospectively analyzed. Subjects were classified in three groups: those who underwent laparoscopic salpingostomy, those treated by expectant management only, and those treated by expectant management but requiring additional treatment.

Results

The rates of tubal patency, intrauterine pregnancy and repeated ectopic pregnancy in the laparoscopic salpingostomy group were 75, 40, and 16%. The rates in the expectant management group were not significantly different: 72, 42 and 15%. Finally, the rates in the extra treatment group were 75, 39 and 15%. Success rate of expectant management was 54%. In 93% of cases expectant management was successfully completed when the initial levels of urinal hCG were less than 3000 mIU/ml and the levels of hCG 48 h later were less than 80% of the initial levels. However, expectant management alone was insufficient and required extra treatment in 90% of cases when the initial levels of hCG were 3000 mIU/ml and above or when the levels of hCG level 48 h later was 80% of initial levels and above.

Conclusions

Expectant management in combination with salpingostomy is not only minimally invasive but also a useful way to preserve fertility. Initial urine hCG levels and their variation over time can help predict whether expectant management will succeed.
A Vascular Hamartoma Arising from the Cervical Spine of a Cat
Authors: Parkes Jennifer D. , Kline Karen L. , Riedesel Elizabeth A. , Haynes Joseph S.
Published: June 2009

A 15-month-old cat presented for evaluation of worsening generalized proprioceptive ataxia. Computed tomography of the cervical spine revealed the presence of a compressive extradural bony mass involving the dorsal aspect of C1. Surgical exploration and debulking of the mass was performed. Histological evaluation of the mass revealed fibrovascular tissue consistent with a vascular hamartoma. This mass was deemed to be originating from the soft tissue associated with the C1 vertebra with subsequent bony proliferation. Surgical debulking of the mass resulted in complete resolution of clinical signs with no evidence of recurrence 2 years after surgery.