bluuebunny/crossref_metadata_2025 huggingface dataset:
MBE growth of ZnSe/MgCdS and ZnCdS/MgCdS superlattices for UV‐A sensors
Authors: Ueno J. , Ogura K. , Ichiba A. , Katsuta S. , Kobayashi M. , Onomitsu K. , Horikoshi Y.
Published: March 2006

ZnSe/MgCdS and ZnCdS/MgCdS superlattices were grown on semi insulating (001) oriented GaAs substrates by molecular beam epitaxy (MBE). The crystal quality and optical properties were examined for both superlattices. The observed photoluminescence (PL) peak intensity of ZnCdS/MgCdS was much stronger than that of ZnSe/MgCdS while ZnSe/MgCdS showed sharper luminescence line width. The PL peak energy position was compared with the theoretical value derived from the Kronig‐Penny model. The degradation of crystal quality was observed by increasing Mg content in MgCdS layer and drastic PL property degradation was observed when the Mg content in the layer exceeded a certain value. Two superlattices were applied to the UV‐A sensor of the metal‐semiconductor‐metal (MSM) configuration. Both photodetectors exhibited a high sensitivity in the UV‐A region with a sharp cut‐off in the visible wavelength region; the ON‐OFF ratio of sensor was about 103 for both structures. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth of boron‐doped ZnTe homoepitaxial layer by metalorganic vapor phase epitaxy
Authors: Saito Katsuhiko , Yamashita Tetsuo , Tanaka Tooru , Nishio Mitsuhiro , Guo Qixin , Ogawa Hiroshi
Published: March 2006

We have investigated boron (B) as a n‐type dopant for ZnTe homoepitaxial layer by atmospheric pressure metalorganic vapor phase epitaxy using triethylboron (TEB). The introduction of TEB induces considerable change in the photoluminescence spectrum of the layer. Two distinctive luminescence peaks associated with excitons bound to neutral dononor and donor‐acceptor pair (DAP) transition are emerged in the spectrum, implying that the incorporated B acts as donor impurity in ZnTe. From the temperature dependence of the PL intensity of DAP recombination, the value of donor level was estimated to be 18 meV. This value seems to be reasonable, comparing with the previous studies on Cl and Al doping of ZnTe. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical anisotropy of CdSe/ZnSe quantum dots
Authors: Kiessling T. , Astakhov G. V. , Platonov A. V. , Slobodskyy T. , Mahapatra S. , Ossau W. , Schmidt G. , Brunner K. , Molenkamp L. W.
Published: March 2006

We present comprehensive studies of in‐plane optical anisotropy in CdSe/ZnSe quantum dot ensembles. The anisotropy reveals itself as circular‐to‐linear polarization conversion and as an alignment occurring at resonant excitation without any applied magnetic fields. The variation of the anisotropy in different dots has been analyzed based on angle scans. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐efficiency low‐threshold optically‐pumped green laser with single CdSe quantum‐disk‐sheet active region
Authors: Ivanov S. V. , Sedova I. V. , Sorokin S. V. , Sitnikova A. A. , Toropov A. A. , Kop'ev P. S. , Lutsenko E. V. , Danilchyk A. V. , Voinilovich A. G. , Zubialevich V. Z. , Gurskii A. L. , Yablonskii G. P.
Published: March 2006

MBE growth and studies of structural, photoluminescence and laser characteristic of Cd(Zn)Se/ZnMgSSe quantum disk optically‐pumped laser heterostructures of a modified design are presented. The design changes include more homogeneous CdSe quantum‐disk‐sheet active region grown by modified migration enhanced epitaxy, rising the thickness and band gap of ZnMgSSe cladding layers, and a choice of proper place for the active region in the superlattice waveguide. Minimum laser threshold, maximum external quantum efficiency and maximum output power of 4.8 kW/cm2, 32%, and 21 W from both facets, respectively, have been achieved at 300 K. The laser internal loss has been estimated as small as 1–2 cm–1. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of CdTe sub‐monolayer stressor on CdSe quantum dot self‐assembling in ZnSe
Authors: Sedova I. V. , Lyublinskaya O. G. , Sorokin S. V. , Sitnikova A. A. , Solnyshkov D. D. , Rykhova O. V. , Toropov A. A. , Ivanov S. V.
Published: March 2006

This paper reports on the attempt to apply the stressor‐controlled quantum dot (QD) fabrication technique to the conventional CdSe/ZnSe nanostructures. Super‐strained CdTe fractional monolayer (Δa/a ∼ 14% for CdTe/ZnSe) grown on top of the Te‐stabilized ZnSe surface prior to deposition of the QD material (CdSe) has been used as a stressor which is expected to affect size, composition and density of CdSe QDs. The grown structures are studied by X‐ray diffraction, transmission‐electron microscopy, photoluminescence (PL) and PL excitation in comparison with conventional CdSe/ZnSe QDs obtained by a modified migration enhanced epitaxy technique. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermal annealing of self‐assembled CdZnSe quantum dots studied by photoluminescence spectroscopy
Authors: Margapoti E. , Worschech L. , Slobodskyy T. , Molenkamp L. W. , Forchel A.
Published: March 2006

Self assembled CdZnSe quantum dots (QDs) embedded in a ZnSe matrix were thermally annealed and the induced interdiffusion between Zn and Cd atoms was investigated by photoluminescence spectroscopy. We observed a blue shift of the QD emission by more than 100 meV. According to a Fickian diffusion model an activation energy of 2.2 eV for the interdiffusion of Cd and Zn between the CdZnSe QDs and the ZnSe barrier is determined. The half widths of the emission lines decrease significantly with increasing annealing temperature, which allows to observe in the spectrum of strongly interdiffused CdZnSe quantum dots a second emission peak. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Energy relaxation in CdSe/ZnSe quantum dots under the strong exciton‐phonon coupling regime
Authors: Platonov A. V. , Kiessling T. , Astakhov G. V. , Maksimov A. A. , Larionov A. V. , Yakovlev D. R. , Slobodskyy T. , Mahapatra S. , Ossau W. , Schmidt G. , Brunner K. , Bayer M. , Molenkamp L. W.
Published: March 2006

Resonant photoluminescence and photoluminescence excitation spectroscopy have been applied to CdSe/ZnSe quantumdots where separation between the quantized levels is close to the optical phonon energy. Astrong relaxation enhancement induced by the optical phonon is observed. The fine structure of the phonon replicas is resolved. It is attributed to the optical phonons with large wave vectors from the symmetrical points of the Brillouin zone. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparative study of self‐assembled CdSe/ZnSe quantum dots grown by variants of conventional MBE
Authors: Mahapatra S. , Brunner K. , Schumacher C. , Kiessling T. , Astakhov G. V. , Bass U. , Margapoti E. , Ossau W. , Geurts J. , Worschech L. , Forchel A. , Molenkamp L. W.
Published: March 2006

The morphology, composition, and optical properties of CdSe/ZnSe quantum dots (QDs), grown by conventional molecular beam epitaxy (MBE) and two other variants of the same (low temperature MBE and in‐situ annealing), have been compared based on the results of high resolution X‐ray diffraction (HRXRD), low temperature micro‐ and ensemble‐photoluminescence (PL), atomic force microscopy (AFM), and Raman spectroscopy (RS) studies. While conventional MBE results in the formation of no discernible QD‐like features, by the alternative methods reported here, discrete CdSe QDs, 1.5 to 15 nm high and with a lower density, could be realised. Shape anisotropy of the dots has also been investigated. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spectroscopic studies of ferromagnetic (Cd,Mn)Te quantum wells
Authors: Kossacki P. , Gaj J. A.
Published: March 2006

A summary of recent optical experiments is presented, elucidating the properties of the carrier‐induced ferromagnetic phase in p‐doped (Cd,Mn)Te quantum wells. A special attention is paid to the existence and properties of the ferromagnetic domains. Spatially‐resolved experiments with a resolution better than 0.5 µm do not show any domain pattern, but time‐resolved experiments, performed in a range from picoseconds to microseconds, supply a strong evidence for the existence of the domains and determine their dynamics. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
QSAR Analysis of the Time‐ and Dose‐Dependent Anti‐Inflammatory in vivo Activity of Substituted Imidazo[1,2‐a]pyridines Using Artificial Neural Networks
Authors: Saxena Anil K. , Schaper Klaus‐Jürgen
Published: March 2006

The quantitative analysis and physicochemical description of time‐ and dose‐dependent in vivo drug effects is problematic as observed effects depend on both pharmacodynamics and pharmacokinetics. These factors depend in a different manner on the physicochemical properties of the investigated drugs. Obviously in vivo effects of drug series are governed by highly nonlinear relationships. As the function relating in vivo anti‐inflammatory effects of the imidazo[1,2‐a]pyridines observed in rats (carrageenan‐induced rat paw edema test) to dose, time, and physicochemical properties could not be modeled explicitly, an attempt was made to train an Artificial Neural Network (ANN) to find the unknown nonlinear relationship between input variables and observed % effect values. The analysis extracted a maximum of information from available in vivo data and resulted in an ANN model that enabled the calculation of dose‐ and property‐dependent anti‐inflammatory activities of a set of 15 imidazopyridines.
Dissociative electron attachment in selected haloalkanes
Authors: Pshenichnyuk S. A. , Pshenichnyuk I. A. , Nafikova E. P. , Asfandiarov N. L.
Published: March 2006

Three mono‐substituted and six poly‐substituted haloalkanes derivatives were investigated by means of negative ion mass spectrometry (NIMS). Available electron transmission spectroscopy (ETS) data were used for the treatment of NIMS results. Comparison of the ETS spectra of mono‐substituted bromo‐ and chloroalkanes show that these families of compounds exhibit similar regularities in the process of NI formation. Capture of the p‐partial wave dominates in the lowest anion state formation. In the series of mono‐substituted bromo‐ and chloroalkanes the energy difference (Shift) between the vertical attachment energy (VAE) in ETS spectra and the maximum of the NI formation in dissociative electron attachment (DEA) spectra correlates approximately linearly with the VAE value for the given molecule. The slopes of these dependencies are different for the mono‐substituted chloro and bromo derivatives. It is conjectured that, in the derivatives di‐substituted in the 1,2‐positions, there is a shallow minimum in the repulsive anion potential curve, which makes possible temporary trapping of the anion. This delay is long enough for the rearrangement process and formation of the Hal ions. This effect is not detected in 1,1‐halogenated derivatives. Copyright © 2006 John Wiley & Sons, Ltd.
High‐throughput determination of carbocysteine in human plasma by liquid chromatography/tandem mass spectrometry: application to a bioequivalence study of two formulations in healthy volunteers
Authors: Bi Hui‐chang , Zhao Li‐zi , Zhong Guo‐ping , Zhou Shufeng , Li Bo , Deng Ying , Chen Xiao , Huang Min
Published: March 2006

A rapid and sensitive liquid chromatography/tandem mass spectrometry (LC/MS/MS) method to determine carbocysteine in human plasma was developed and fully validated. After methanol‐induced protein precipitation of the plasma samples, carbocysteine was subjected to LC/MS/MS analysis using electrospray ionization (ESI). The MS system was operated in the selected ion monitoring (SRM) mode. Chromatographic separation was performed on a Hypurity C18column (i.d. 2.1 mm × 50 mm, particle size 5 µm). The method had a chromatographic running time of 2.0 min and linear calibration curves over the concentration ranges of 0.1–20 µg/mL for carbocysteine. The lower limit of quantification (LLOQ) of the method was 0.1 µg/mL for carbocysteine. The intra‐ and inter‐day precision was less than 7% for all quality control samples at concentrations of 0.5, 2.0, and 10.0 µg/mL. These results indicate that the method was efficient with a simple preparation procedure and a very short running time (2.0 min) for carbocysteine compared with methods reported in the literature and had high selectivity, acceptable accuracy, precision and sensitivity. The validated LC/MS/MS method has been successfully used to a bioequivalence study of two tablet formulations of carbocysteine in healthy volunteers. Copyright © 2006 John Wiley & Sons, Ltd.
Characterization of decomposition products and preclinical and low dose clinical pharmacokinetics of decitabine (5‐aza‐2′‐deoxycytidine) by a new liquid chromatography/tandem mass spectrometry quantification method
Authors: Liu Zhongfa , Marcucci Guido , Byrd John C. , Grever Michael , Xiao Jim , Chan Kenneth K.
Published: March 2006

Aberrant DNA methylation patterns resulting in gene transcriptional repression are observed in numerous cancers. Decitabine, a DNA methyltransferase inhibitor, is being clinically evaluated in patients with hematologic malignancies and solid tumors. Decitabine is rather unstable and decomposes to 1‐beta‐D‐2′‐deoxyribofuranosyl‐3‐guanylurea under basic conditions and several additional unknown products under neutral conditions. This has greatly limited application of pharmacokinetic assays to clinical development of decitabine. In this paper, a high‐performance liquid chromatography/ultraviolet multi‐stage mass spectrometry (HPLC‐UV‐MSn) study of the decomposition of decitabine in water and human plasma revealed that these previously unknown products are isomers of the intermediates formyl‐1‐beta‐D‐2′‐deoxyribofuranosyl‐3‐guanylurea and 1‐beta‐D‐2′‐deoxyribofuranosyl‐3‐guanylurea. A HPLC tandem mass spectrometry (MS/MS) method for the determination of decitabine concentrations in human and rat plasma has been developed. This method was based on a specific fragmentation pathway of the molecular ion of decitabine at m/z 229 to generate a unique fragment ion at m/z 113 under collision‐induced dissociation. Separation of decitabine and the stable internal standard dihydro‐5‐aza‐cytidine from the endogenous interfering substance in plasma extract was carried out on a C18 Aquasil column under an isocratic elution with a mobile phase consisting of 5% water/acetonitrile and 10 mM ammonium formate. The detection of decitabine was via selected reaction monitoring (SRM, 229 > 113), and its ionization was enhanced by post‐column addition of acetonitrile. Effects of sample preparation and handling parameters on the stability of decitabine were also evaluated in human plasma at various temperatures. The accuracy and precision of this assay showed a coefficient of variation of <15% over the range of 0.5–25 ng for rat plasma and 0.1–25 ng for human plasma injected on‐column. Pharmacokinetics of decitabine in rats following intravenous doses of 1.0 and 5.0 mg/kg were characterized. In the rat, plasma concentration‐time profiles were found to follow a biexponential decline and the pharmacokinetics was dose‐independent. Application of this decitabine pharmacokinetic assay to human studies is therefore justified and ongoing. Copyright © 2006 John Wiley & Sons, Ltd.
Phosphopeptide quantitation using amine‐reactive isobaric tagging reagents and tandem mass spectrometry: application to proteins isolated by gel electrophoresis
Authors: Sachon E. , Mohammed S. , Bache N. , Jensen O. N.
Published: March 2006

Polyacrylamide gel electrophoresis is widely used for protein separation and it is frequently the final step in protein purification in biochemistry and proteomics. Using a commercially available amine‐reactive isobaric tagging reagent (iTRAQ) and mass spectrometry we obtained reproducible, quantitative data from peptides derived by tryptic in‐gel digestion of proteins and phosphoproteins. The protocol combines optimized reaction conditions, miniaturized peptide handling techniques and tandem mass spectrometry to quantify low‐ to sub‐picomole amounts of (phospho)proteins that were isolated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE). Immobilized metal affinity chromatography (Fe(III)‐IMAC) was efficient for removal of excess reagents and for enrichment of derivatized phosphopeptides prior to matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) analysis. Phosphopeptide abundance was determined by liquid chromatography/tandem mass (LC/MS/MS) using either MALDI time‐of‐flight/time‐of‐flight (TOF/TOF) MS/MS or electrospray ionization quadrupole time‐of‐flight (ESI‐QTOF) MS/MS instruments. Chemically labeled isobaric phosphopeptides, differing only by the position of the phosphate group, were distinguished and characterized by LC/MS/MS based on their LC elution profile and distinct MS/MS spectra. We expect this quantitative mass spectrometry method to be suitable for systematic, comparative analysis of molecular variants of proteins isolated by gel electrophoresis. Copyright © 2006 John Wiley & Sons, Ltd.
Isotopic analysis of ethanol: study on 18O/16O measurement using a high‐temperature pyrolysis system coupled to an isotope ratio mass spectrometer
Authors: Calderone Giovanni , Reniero Fabiano , Guillou Claude
Published: March 2006

The original article to which this Erratum refers was published in Rapid Commun. Mass Spectrom. 20; 2006, 937–940.
Silica retention in the Iron Gate I reservoir on the Danube River: the role of side bays as nutrient sinks
Authors: McGinnis Daniel F. , Bocaniov Serghei , Teodoru Cristian , Friedl Gabriela , Lorke Andreas , Wüest Alfred
Published: March 2006

There are longstanding concerns about the environmental impacts of super‐dams such as Iron Gate I, the Danube River's largest hydropower scheme. Iron Gate I is suspected of trapping up to 80% (∼590 000 tons per year) of dissolved silica in the form of sedimenting diatom frustules and 30 000 000 tons per year of suspended solids. This study, however, indicates that (i) conditions are unfavorable for primary production in Iron Gate I except for the small quiescent center of Orsova Bay, and the diatom production is much too low for the suspected silica uptake; (ii) Orsova Bay is the most important sediment trap as resuspension does not occur, with ∼1% (82 000 tons per year) suspended solids retention, and (iii) also the only significant silica trap, with ∼0.2% (1000 tons per year) retention. It is most conservatively estimated that no more than 5% of dissolved silica can be retained by the Iron Gate I reservoir, and therefore the earlier estimate of the huge retention can definitely be ruled out. Copyright © 2006 John Wiley & Sons, Ltd.
A parallel cost‐based abductive reasoning system on workstation cluster
Authors: Kato Shohei , Nakamura Tomonori , Itoh Hidenori
Published: February 2006

This paper proposes a method for dynamic load balancing which works efficiently in the workstation cluster environment. A parallel abductive reasoning system based on the proposed method is also proposed. In the workstation cluster environment, parallel processing is performed using workstations with various processing abilities and loads. Thus, dynamic load balancing must consider the performance and loading conditions of the workstations. This paper proposes a method of estimating the processing ability of the workstation during operation, and also a dynamic load balancing algorithm to balance the estimated conditions. Using the proposed method, a parallel abductive reasoning system which can derive the most preferable explanation for a given observation is implemented. The results of experiments on the system are also reported. © 2006 Wiley Periodicals, Inc. Syst Comp Jpn, 37(3): 80–89, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10190
Restoration of missing intensity of still images by using optical flow
Authors: Ogawa Takahiro , Haseyama Miki , Kitajima Hideo
Published: February 2006

This paper proposes an accurate method for the restoration of missing intensities of still images by using the optical flow. It is important in restoration to reconstruct missing edges correctly. Therefore, this paper modifies the optical flow conventionally used for motion analysis in video images and applies it to the restoration of missing intensities. Further, the proposed method introduces a new index expressing the correlation of intensities between two pixels into the scheme for calculation of the optical flow in order to obtain a flow which gives more accurate estimated values. The optical flow calculated by this index provides the pixel from the neighborhood whose intensity is most similar to that of the target pixel, so that the estimated intensity is not affected by pixels whose intensities are quite different. Consequently, even when multiple edges pass through the missing area or the direction of the edge changes significantly inside the area, the proposed method can reconstruct the edges correctly. Some experimental results are presented in order to verify the high performance of the proposed method. © 2006 Wiley Periodicals, Inc. Syst Comp Jpn, 37(3): 49–57, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20376
Development of a video‐rate rangefinder system using light intensity modulation with scanning laser light
Authors: Azuma Takeo , Uomori Kenya , Nobori Kunio , Morimura Atsushi
Published: February 2006

We have developed an active rangefinder system that can obtain depth images at video field rates by improving Carrihill's intensity ratio depth sensor. Although the depth sensor can be made at low cost, its depth precision is affected by background light, video noise, and the motion of objects. To reduce such influences, first we used a laser line pattern scanned by a rotating mirror as a light source and a camera with an optical narrow‐bandpass filter—an interference filter—to overcome the background light. Second, we corrected the projected light power at the camera's peripheral field to decrease depth error there. Third, we performed inter‐field median filtering of measured depths to decrease the influence of object motion. As a result, we achieved standard deviations of depths 1.4% and 2.1% in a range of 2.2 to 3 and 3.2 to 4 m, respectively. © 2006 Wiley Periodicals, Inc. Syst Comp Jpn, 37(3): 20–31, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20423
Development of processor cores for digital consumer appliances
Authors: Arakawa Fumio , Yamada Tetsuya , Okada Takashi , Ishikawa Makoto , Kondo Yuki , Ozawa Motokazu , Kodama Tomoyuki , Nishii Osamu , Hattori Toshihiro , Kamei Tatsuya , Nishimoto Junichi , Yoshioka Shinichi
Published: February 2006

Embedded processors are increasingly being used in digital consumer appliances such as cellular phones, digital still/video cameras, and car navigation systems. They must therefore deliver high performance within a reasonable area and power consumption level, and be flexible to meet a wide range of requirements for various applications. In this paper, we introduce our latest processor core SH‐X developed under the above background. The low‐power version of the SH‐X core achieves 360 MIPS with a power of 80 mW resulting in the high power‐performance ratio of 4500 MIPS/W. The standard version achieves 720 MIPS with a power of 250 mW, 2.8 GFLOPS, and 36M polygons/s graphics performance. The leak currents in the resume standby and U‐standby modes are 100 and 10µA, respectively. The resume standby mode can return the status before the standby in only 3 ms, while the U‐standby mode requires reset sequence to restart. © 2006 Wiley Periodicals, Inc. Syst Comp Jpn, 37(3): 10–19, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20450
Embedding of time series data by using dynamic time warping distances
Authors: Mizuhara Yuko , Hayashi Akira , Suematsu Nobuo
Published: February 2006

We propose an approach to embedding time series data in a vector space based on the distances obtained from Dynamic Time Warping (DTW), and classifying them in the embedded space. Under the problem formulation in which both labeled data and unlabeled data are given beforehand, we consider three embeddings: embedding in a Euclidean space by MDS, embedding in a pseudo‐Euclidean space, and embedding in a Euclidean space by the Laplacian eigenmap technique. We have found through analysis and experiment that embedding by the Laplacian eigenmap method leads to the best classification results. Furthermore, the proposed approach with Laplacian eigenmap embedding gives better performance than theknearest neighbor method. © 2006 Wiley Periodicals, Inc. Syst Comp Jpn, 37(3): 1–9, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20486
Software experience when using ontologies in a multi‐agent system for automated planning and scheduling
Authors: González E. J. , Hamilton A. F. , Moreno L. , Marichal R. L. , Muñoz V.
Published: March 2006

The main aim of this paper is to present the software experience when using multi‐agent systems (MASs) and ontologies in the development of a sample application. In particular, the authors have implemented a MAS for the planning and scheduling of a University Research Group. This MAS, called MASplan, should help group members to find the best possible time frames to hold a meeting and to designate the use of common resources. Copyright © 2006 John Wiley & Sons, Ltd.
Medium access control in mobilead hocnetworks: challenges and solutions
Authors: Zhai Hongqiang , Wang Jianfeng , Chen Xiang , Fang Yuguang
Published: February 2006

Mobilead hocnetworks (MANETs) are useful in environment where fixed network infrastructure is unavailable. To function normally, MANETs demand an efficient and distributed medium access control (MAC) protocol. However, characteristics of MANETs such as radio link vulnerability, mobility, limited power pose great challenges on MAC design. This paper surveys the recent advances in MAC design for MANETs. We first identify the challenges that are facing MAC in MANETs. Then we discuss the proposed MAC schemes according to their design goals, focusing on some critical design issues, and tradeoffs. Finally, we point out some future research directions. Copyright © 2006 John Wiley & Sons, Ltd.
ACR: an adaptive communication‐aware routing through maximally zone‐disjoint shortest paths inad hocwireless networks with directional antenna
Authors: Ueda Tetsuro , Tanaka Shinsuke , Komiyama Bokuji , Roy Siuli , Saha Dola , Bandyopadhyay Somprakash
Published: February 2006

A fundamental problem that distinguishes wireless networks from wired networks is the mutual interference between routes within the proximity of each other. This phenomenon is known as route coupling and it restricts the possibility of occurrence of simultaneous communications along the coupled routes. In this context, the use of directional antenna, having smaller transmission beam‐width compared to omni‐directional antenna, helps to easily decouple interfering routes, and improves network performance through space division multiple access (SDMA). However, even if we have an efficient directional MAC protocol, it alone would not be able to guarantee good system performance, unless we have a proper routing strategy in place that exploits the advantages of directional antenna. So, in this paper, an adaptive routing strategy is proposed that exploits the advantages of directional antenna inad hocnetworks through the selection of maximally zone‐disjoint shortest routes. Zone‐disjoint routes would minimize the effect of route coupling and improve the overall network performance. The proposed strategy ensures effective load balancing and is applied to design and implement both single path and multipath routing protocols in ad hoc networks with directional antennas. Simulation results obtained on QualNet network simulator shows the effectiveness of the proposed routing protocols. Copyright © 2006 John Wiley & Sons, Ltd.
Energy‐efficient broadcast and multicast routing in multihopad hocwirelessnetworks
Authors: Cheng Maggie Xiaoyan , Sun Jianhua , Min Manki , Li Yingshu , Wu Weili
Published: February 2006

This paper addresses the problem of broadcasting and multicasting in large scale multihopad hocwireless networks. We focus on the energy‐efficient broadcast routing in stationary networks and consider the case where wireless nodes can dynamically control their transmission power for each broadcast session.

Minimum spanning tree (MST) has the property that the longest edge in the tree is the shortest among all the spanning trees. We introduce a new algorithm called minimum longest edge (MLE) that constructs a broadcast tree based on MST, and for networks where nodes have different energy reserves, we introduce minimum weight incremental arborescence (MWIA) algorithm to compute the broadcast tree. Multicast tree can be obtained by pruning broadcast tree. These algorithms provide a scheme to balance the energy consumption among all nodes. The simulation results show that MLE and MWIA improved the energy balance and network lifetime for a wide range of networks, and the improvement is more significant when the network size grows. Copyright © 2006 John Wiley & Sons, Ltd.
Interoperability of multicast routing protocols in wireless ad hoc networks
Authors: Viswanath Kumar , Obraczka Katia
Published: February 2006

Although multihop ad hoc networks (MANETs) have typically been considered as isolated, stand‐alone networks with no connection to the Internet, it is quite likely that future internetworks may interconnect numerous MANET clouds, each running different routing mechanisms. This could be primarily dictated by administrative constraints or different network functional and performance requirements and can result in scenarios where nodes belonging to different MANET clouds running different routing mechanisms may wish to communicate with one another. In this paper, we introduce techniques to allow interoperability of various multicast routing protocols in MANETs. In particular, we investigate two different interoperability techniques, that is, flooding‐based interoperability and facilitator‐assisted interoperability. Our preliminary evaluation of the two techniques indicates that the flooding‐based mechanism is best suited for scenarios involving intermittent communications between different ad hoc domains whereas the facilitator‐assisted approach is best suited for data intensive applications such as video‐conferencing. Copyright © 2006 John Wiley & Sons, Ltd.
GARA: a geometry aided routing algorithm
Authors: Daescu O. , Fasui G. , Haridoss K.
Published: February 2006

We consider the problem of finding themost sustainable path(MSP) between two nodes in a wireless mobilead hocnetwork (MANET). A MSP between two nodes is a path that maximizes the probability of path existence under some probability model. We show how to exploit geometric properties in computing the reliability of a path in the resulting mobility graphG, prove that simple shortest path algorithms such as Dijkstra's algorithm cannot be directly applied in this scenario, and propose an algorithm for computing a single pair MSP in a modified representation ofG. To improve reliability in routing, we also discuss the computation ofkmost sustainable paths under the link metric and under the standard shortest path formulation. Copyright © 2006 John Wiley & Sons, Ltd.
Gene silencing in mosquito salivary glands by RNAi
Authors: Boisson Bertrand , Jacques Jean Claude , Choumet Valérie , Martin Estelle , Xu Jiannong , Vernick Ken , Bourgouin Catherine
Published: March 2006

Salivary glands are the ultimate site of development in the insect of mosquito born pathogens such as Plasmodium. Mosquito salivary glands also secrete components involved in anti‐haemostatic activities and allergic reactions. We investigated the feasibility of RNAi as a tool for functional analysis of genes expressed in Anopheles gambiae salivary glands. We show that specific gene silencing in salivary glands requires the use of large amounts of dsRNA, condition that differs from those for efficient RNAi in other mosquito tissues. Using this protocol, we demonstrated the role of AgApy, which encodes an apyrase, in the probing behaviour of An. gambiae.
The interplay between virus infection and the cellular RNA interference machinery
Authors: Berkhout Ben , Haasnoot Joost
Published: March 2006

RNA interference (RNAi) plays a pivotal role in the regulation of gene expression to control cell development and differentiation. In plants, insects and nematodes RNAi also functions as an innate defence response against viruses. Similarly, there is accumulating evidence that RNAi functions as an antiviral defence mechanism in mammalian cells. Viruses have evolved highly sophisticated mechanisms for interacting with the host cell machinery, and recent evidence indicates that this also involves RNAi pathways. The cellular RNAi machinery can inhibit virus replication, but viruses may also exploit the RNAi machinery for their own replication. In addition, viruses can encode proteins or RNA molecules that suppress existing RNAi pathways or trigger the silencing of specific host genes. Besides the natural interplay between RNAi and viruses, induced RNAi provides an attractive therapy approach for the fight against human pathogenic viruses. Here, we summarize the latest news on virus–RNAi interactions and RNAi based antiviral therapy.
Neural Repair for Sensory Restoration in a Groin Flap
Authors: JOSHI B. B.
Published: March 2006

A preliminary study of the recovery of sensation in groin flaps, after suture of the lateral cutaneous branches of the twelfth thoracic nerve supplying the groin flap with those of the hand, is described. This appears to be a worthwhile procedure.
A Review of 100 Flexor Tendon Reconstructions with Prosthesis
Authors: HONNER RICHARD , MEARES ALLAN
Published: March 2006

A series of one hundred cases where silicone rods were used to prepare a bed for flexor tendon grafting is examined, the main indication for this technique being circumstances where one stage tendon grafting was likely to have a poor result. The main complications noted were a synovitis around the silastic rods, infection, and loss of the distal attachment of the silastic rod. The overall results were satisfactory.
Stabilization of the First Metacarpophalangeal and Terminal Joints of the Thumb
Authors: HARRISON STEWART , SMITH PAUL , MAXWELL DAVID
Published: March 2006

The results of the first hundred cases of Arthrodesis of joints of the thumb are presented and reviewed.
Use of the Intramedullary Polypropylene Peg for Joint Stabilization in Leprosy
Authors: FINSETH FREDERICK , HARRISON STEWART
Published: March 2006

Joint arthrodesis is indicated when motion in a joint cannot be restored, and that joint requires stabilization in an optimal functional position.

The Harrison Intramedullary peg has been used to advantage for this purpose in hand reconstruction in leprosy in a rural developing area. It is a method to be considered for selected cases requiring joint stabilization to improve total hand function.
Acquired Club Hand — A Case Report
Authors: DREYFUSS U.
Published: March 2006

An exceptional case of acquired radial club hand is recorded. Although clinically similar to the congenital club hand, it has developed in a normal hand, as a result of osteomyelitis.
Congenital Absence of the Flexor Pollicis Longus — A Case Report —
Authors: MIURA TAKAYUKI
Published: March 2006

Congenital absence of the flexor pollicis Iongus, associated with hypoplasia of the thumb, is an unusual anomaly. A case of congenital absence of the flexor pollicis longus without hypoplasia or aplasia of the thumb and thenar muscles, which is described, is very rare.

Surgical treatment for the transfer of the ring finger flexor superficialis tendon to provide the thumb interphalangeal joint with flexion resulted in a significant improvement in pinch.
Streptococcal Infection with Digital Gangrene
Authors: SMITH R. B.
Published: March 2006

Two cases of streptococcal cellulitis of the hand are described in which digital gangrene occurred. A review of the literature is included.
Dermatitis Artefacta
Authors: BROUGH M. D.
Published: March 2006

An unusual case of dermatitis artefacta is presented. The patient lost the whole of the index finger of his dominant hand before the diagnosis was established. The motive was financial gain. The literature on self-inflicted disease is reviewed.
Cystic Tuberculosis of a Metacarpal
Authors: FLOWERS MICHAEL W.
Published: March 2006

A white woman of thirty-two years presented with tuberculous osteitis of the third metacarpal head, secondary to previously undetected active pulmonary disease. The problems of diagnosis are illustrated by review of her history, and the literature is discussed.
Eliminating the Gap in Flexor Tendon Surgery
Authors: BECKER HILTON , DAVIDOFF MICHAEL
Published: March 2006

A new method of tendon suture has been designed to eliminate the development of a gap when tension is applied to the repair. It has been demonstrated to resist distraction at relatively high tensions on cadaveric tendon. The possible advantages of the technique are discussed.
Survival characteristics of Salmonella enterica serovar Enteritidis in chicken egg albumen
Authors: KANG H. , LOUI C. , CLAVIJO R. I. , RILEY L. W. , LU S.
Published: February 2006

Salmonella enterica serovar Enteritidis (SE) is a major foodborne pathogen primarily causing human infection through contaminated chicken eggs. To understand how SE survives in chicken egg albumen, we systematically and quantitatively analysed the survival properties of SE in egg albumen and identified factors affecting its survival. Survival assays of SE in egg indicate that egg albumen restricted the growth of SE. A major factor that controlled SE's growth in egg albumen was iron restriction, since egg albumen supplemented with iron allowed SE to grow, and iron acquisition mutants of SE showed decreased survival in egg albumen. In addition, low pH of albumen, high concentrations of bacteria and low incubation temperatures of bacteria with albumen facilitates the survival of SE. Our results suggest that egg albumen uses multiple mechanisms to control SE including iron limitation, surface interaction and possible enzymatic activities.
Conservation implications of the drinking habits of Black-cheeked Lovebirds Agapornis nigrigenis in Zambia
Authors: WARBURTON LOUISE S. , PERRIN MICHAEL R.
Published: March 2006

Since 1950, the annual rainfall in the habitat of Black-cheeked Lovebirds Agapornis nigrigenis has decreased, increasing dependence on artificial water supplies. In this study, the seasonal water requirements and drinking behaviour of the lovebirds in their natural habitat were investigated. During the dry season, lovebirds drank at the same water-point in the early morning and late afternoon. Flock sizes of birds at drinking sites ranged from 1 to 175 individuals. Birds from one locale all drank at the same waterhole. Black-cheeked Lovebirds were vigilant and highly cautious drinkers that did not drink at waterholes when disturbed by humans or livestock. The implications for conservation of the species are discussed. Since water availability is a limiting factor for the Black-cheeked Lovebird, gradual desiccation of its habitat has caused the reduction of its small distributional range. Because of increasing dependence on artificial water supplies in a highly localized distribution the priority for conservation management of the species must be creating and maintaining water resources with minimal external disturbance.
Captive Hill Mynah Gracula religiosa breeding success: potential for bird conservation in Thailand?
Authors: ARCHAWARANON MANEE
Published: March 2006

Hill Mynah Gracula religiosa is one of the most popular bird pets worldwide due to its ability to mimic diverse sounds, especially human speech. However, Mynahs have rarely been bred in captivity, so nestlings from natural populations are in large demand, resulting in many populations being threatened with extinction. Both subspecies in Thailand, intermedia and religiosa, are costly and desired in the pet market. Captive breeding is one of the most practical strategies to solve a conservation problem of this nature and this report describes a success in breeding Hill Mynahs in captivity. Mated pairs were given free access to food, nest-cavities and nest materials. Reproductive behaviour in captivity was not different from that in the wild, with the exception that breeding occurred throughout the year, even during the non-breeding season for wild populations. Although there are doubts concerning the reintroduction of captive-bred birds and whether successful Hill Mynah breeding in captivity is an economically competitive alternative to poaching, it ensures species survival in captivity as the risk of extinction increases.
Low reproductive success of Campo Suiriri (Suiriri affinis) and Chapada Flycatcher (S. islerorum) in the central Brazilian Cerrado
Authors: LOPES LEONARDO ESTEVES , MARINI MIGUEL ÂNGELO
Published: March 2006

We investigated the reproductive success of Campo Suiriri (Suiriri affinis) and Chapada Flycatcher (S. islerorum) in the Estação Ecológica de Águas Emendadas, Central Brazil. Between June and December 2003, we monitored 25 nests of Campo Suiriri and 20 nests of Chapada Flycatcher. The simple percentage of successful nests was 32% for Campo Suiriri and 10% for Chapada Flycatcher, whereas the reproductive success calculated by the Mayfield method was 19% for Campo Suiriri and 14% for Chapada Flycatcher. The estimated values of daily survivorship rate (DSR) for Campo Suiriri are as follows: egg period 0.971 and nestling period 0.944. For Chapada Flycatcher the figures were 0.964 and 0.930, respectively. No differences in DSRs between species or periods were statistically significant. All nest losses of Campo Suiriri were due to predation, while for Chapada Flycatcher predation accounted for 78% of nest losses and the remaining 22% was due to parasitism by botfly larvae (Philornis sp.). The low reproductive success of Chapada Flycatcher is close to the lowest values recorded for Neotropical birds and might be a threat to this species and an important variable in the determination of its conservation status.
A micromodel investigation of two‐phase matrix‐fracture transfer mechanisms
Authors: Rangel‐German E. R. , Kovscek A. R.
Published: March 2006

Micromodels employing a two‐dimensional representation of pore space were used to observe directly (via microscope) water imbibition into a matrix and matrix‐fracture interactions between wetting and nonwetting fluids. Within a single field of view, some pores are responsible for the uptake of water, whereas immediately adjacent pores expel nonwetting phase into the fracture. When water flow through fractures is relatively slow and fluid transfer from the fracture is relatively rapid, imbibition is microscopically cocurrent and micromodel observations teach that uptake of the wetting phase by the matrix correlates directly with the volume of water injected. This mode of transfer is coined a filling fracture. On the other hand, when fractures fill with water quickly relative to the rate of matrix‐fracture transfer, the mass of water imbibed scales with the square root of time. Here imbibition is found to be countercurrent at the pore level. In the countercurrent mode, significant channeling of the nonwetting phase through the continuous wetting phase is observed that reduces the efficiency of water infiltration. Overall, it is found that the rate of water uptake from a fracture into an unsaturated matrix and the pore‐level pattern of water infiltration depend critically on the rate of water infiltration through fractures.
Geomagnetic field behavior during the Iceland Basin and Laschamp geomagnetic excursions: A simple transitional field geometry?
Authors: Laj Carlo , Kissel Catherine , Roberts Andrew P.
Published: March 2006

We present four new records of the Iceland Basin Excursion (IBE) and five new records of the Laschamp Excursion (LE) obtained from rapidly deposited marine sediments in the North Atlantic Ocean, the Nordic Seas, the Gulf of Mexico, the South China Sea, and the southern Indian Ocean. Marked minima in relative paleointensity correspond with the paleomagnetic directional changes associated with all of the excursion records. The virtual geomagnetic pole (VGP) paths of the four IBE records are all similar. The VGPs move southward over Europe and Africa, reaching the southern hemisphere (three reach Antarctica), and then move to more eastern longitudes before returning northward over Australia and east Asia, describing a large counterclockwise loop. The same VGP pattern is observed in other published records. The VGP paths observed for the LE are similar to those of the IBE; however, they loop clockwise instead of counterclockwise. Despite the different sense of looping, the marked similarity among the paths for the two excursions suggests that a similar, relatively simple geometry dominated the transitional field during both the IBE and the LE. Similar dynamo mechanisms must therefore have been active in the Earth's core for both excursions. The duration of the excursions is estimated at <2,000 years, which supports the suggestion that a difference exists between the mechanisms for excursions and reversals. However, the coincidence of the longitudinal bands for VGPs associated with excursions compared to some reversal paths could also indicate an inherent link between the mechanisms for reversals and excursions.
Radon loss across the water‐air interface (Gulf of Thailand) estimated experimentally from 222Rn‐224Ra
Authors: Dulaiova H. , Burnett W. C.
Published: March 2006

We used 222Rn and 224Ra measured in the Upper Gulf of Thailand to estimate 222Rn atmospheric evasion across the water‐air interface. The Chao Phraya estuary represents a steady‐state source of these tracers and we looked at their horizontal distribution on a transect leading away from the estuary into the Gulf. The isotopes 222Rn and 224Ra have very similar half‐lives and are affected in the same manner by mixing processes but only radon will emanate to the atmosphere. We thus are able to estimate the radon air‐water exchange rate from the difference in the slopes of the 222Rn and 224Ra horizontal distributions. Estimated gas exchange velocities (k) based on our results were 1.1 cm hr−1 in the dry season (January 2004) and 2.1 cm hr−1 during the wet season (July 2004). These rates agreed reasonably well with some theoretical models developed for lakes, estuaries and coastal systems.
Evidence suggesting fluid flow beneath Japan due to periodic seismic triggering from the 2004 Sumatra‐Andaman earthquake
Authors: Miyazawa Masatoshi , Mori Jim
Published: March 2006

We show that very large surface waves from the 2004 Sumatra‐Andaman earthquake (M9.2) triggered deep low‐frequency (DLF) seismic tremors beneath Japan over a 500 km wide region. The triggered seismicity was periodically excited, synchronized with the amplitudes and phases of the oscillatory surface waves incident on the region. Periodic excitation implies that the specific phase of the surface waves plays an important role for the triggering. Estimation of stress changes in the source regions showed that the volumetric dilatation larger than ∼10−8 was the predominant factor for triggering, thereby strongly supporting the hypothesis that DLF events are caused by processes related to fluid flow.