bluuebunny/crossref_metadata_2025 huggingface dataset:
An approach to quantitative classification of nutrient regimes of forest soils
Authors: Courtin P. J. , Klinka K. , Feller M. C. , Demaerschalk J. P.
Published: March 2010

Many workers have classified nutrient regimes of forest soils, but there have been few attempts to provide an objective means of defining soil nutrient regimes. This objective was accomplished in the present study by numerical analysis conducted on 195 soil samples of vegetation and soils from coastal British Columbia. The differentiating characteristics used in the classification were pH (H2O) and the C/N ratio of the humus forms; and total soil nitrogen (kg/ha) and sum of exchangeable calcium, magnesium, and potassium (kg/ha) within the soil rooting zone. Numerical analysis distinguished seven soil groups. These groups were related to the floristic composition of understory vegetation and to forest productivity as indicated by site index. These vegetation – soil relationships were then used to assign the soil groups into five soil nutrient regime classes: very poor, poor, medium, rich, and very rich.
Community organization: effects of landscape fragmentation
Authors: Burgess Robert L.
Published: March 2010

All over the world, natural terrestrial ecosystems have been subjected to a wide variety of human impacts. Most noticeable are activities and processes associated with agriculture, forestry, mining, and urban development. Results range from virtual obliterations of natural communities through varying degrees of fragmentation to a series of preserves and natural areas. Studies of many taxa, both plant and animal, indicate numerous effects associated with the loss of contiguity, reduction in total area, relationship to physical factors, and increasing separation of remaining fragments. The theory of island biogeography has been tested in many kinds of landscapes and for many groups of organisms. The great differences between true islands and terrestrial "habitat islands" lead to inconclusive results in many investigations and to major questions concerning the applicability of the equilibrium model to fragmented terrestrial landscapes. This paper attempts to summarize indicative examples that have a bearing on community structure and organization and to present some ideas for future work in landscape management and its relation to species diversity, natural area preservation, and continued ecosystem integrity, viability, stability, and vitality.
Polytropic solutions to the problem of spherically symmetric flow of an ideal gas
Authors: Summers D.
Published: March 2010

An ideal, compressible gas is considered in steady, spherically symmetric, purely radial motion in the presence of a gravitating point mass situated at the origin of coordinates. The gas pressure p and mass density ρ are assumed to satisfy a simple polytrope law, [Formula: see text], where β is the polytropic index which is assumed to take on any real value; the self-gravitation of the gas is neglected. The model equations, which are expressed in a form appropriate to both the expansion and accretion cases, reduce to two non-linear ordinary differential equations, for which Bernoulli integrals are readily found. Singular points of the differential equations are analyzed, and the complete set of asymptotic solutions for the velocity, temperature and Mach number are given for λ → 0 and λ → ∞, where λ [Formula: see text] (radial coordinate)−1, as well as a special class of solutions valid for λ → constant (≠ 0). Families of velocity profiles are sketched which are representative of the complete range of β. The polytropic model, special cases of which have been used successfully in astrophysics in stellar wind and accretion problems, is here cast in general fluid-dynamic terms so that the complete set of solutions obtained may be applicable to a wide class of gas expansion and accretion problems.
Photoproduction of positive pions from 16O at medium energies
Authors: Devanathan V. , Girija V. , Prasad G. N. Sivarama
Published: March 2010

The reaction 16O(γ,π+)16N has been studied in the distorted wave impulse approximation (DWIA) using the free-nucleon photopion amplitude. The nuclear distortion effects on the emitted pion and also the effect of nuclear structure are investigated in detail. The effect of nuclear distortion is found to be small at lower energies but is of great importance resulting in large absorption of pions around the (3,3) resonance. Using realistic nuclear wave functions, it is found that the DWIA yields cross sections in fair agreement with the experimental data at γ-ray energies above 230 MeV but higher values at lower energies.
Further comments on the equivalence of Abraham's, Minkowski's, and others' electrodynamics
Authors: Maugin Gérard A.
Published: March 2010

Arguments recently proposed by Kranyš concerning the nondistinguishability between Abraham's and Minkowski's electromagnetic contributions to the total energy-momentum tensor of the same relativistic, thermodynamically closed system are extended to other electromagnetic energy-momentum tensors (as proposed by Grot and Eringen and de Groot and Suttorp). The adjustment of the corresponding "matter" contribution, which occurs in each element of the canonical space-time decomposition of the total energy-momentum tensor, is exhibited in those different cases. For dissipation-free systems this adjustment can be achieved for each case by means of an ad hoc Legendre transformation on the internal energy density. The arguments used do not presuppose any isotropy and linearity of the medium and can be readily extended to the cases of media with hysteresis and media endowed with intrinsic spins, be they of a fluid-like or solid-like type of mechanical behavior.
Superoperator methods of calculating cross sections: III. Unified description of classical and quantal scattering
Authors: Turner R. E. , Snider R. F.
Published: March 2010

It is shown how differential cross sections can be obtained from the time dependence of phase space packets. This procedure is valid both for classical and quantum mechanics. Two methods are described. In one the trajectory of the packet is emphasized, while in the second the packet is appropriately spread to infinite size. Both methods are applicable to either mechanics. It is shown how the quantal results agree with those of the stationary state approach as formulated in terms of the density operator. The description is also used to elucidate the difference between the scattered flux and the generalized flux that arises naturally in the superoperator formulation.
The disposition of gas–oil mixtures trapped under ice
Authors: Topham D. R.
Published: March 2010

A number of stable configurations which can be formed from mixtures of oil and gas trapped in water under a solid surface is examined. In particular, the problem of a lens of oil lying within a sessile bubble of gas is solved, and two forms of stable solution are found; a discrete lens of oil lying in the bottom of the gas bubble and a double sessile drop formation with the oil completely enclosing the gas. A comparison of the energies of the formation indicates the ranges of oil properties where each configuration is likely to be found. The results are applied to the specific case of crude oils trapped under ice and an appropriate existence diagram constructed.
Experimental uniaxial stress and strain derivatives of the Fermi surface of rhenium
Authors: Fawcett E. , Holroyd F. W. , Perz J. M.
Published: March 2010

The derivatives of the areas of extremal orbits on all the small sheets of the Fermi surface of rhenium, with respect to stress and strain along the hexad axis, have been determined from simultaneous measurements of Landau quantum oscillations in magnetostriction and torque, and also in sound velocity and torque. Strong anisotropy is observed in the stress derivatives of orbits in zones five and six as the direction of the magnetic field defining the normal to the orbit is varied; the anisotropy is most pronounced for orbits which come close to the line of degeneracy AL on the hexagonal Brillouin zone face. The derivatives of the small void in zone eight are found to be very large; this is consistent with the results of band structure calculations which show that this feature of the Fermi surface is very sensitive to small changes in the Fermi energy. Cyclotron effective masses for a number of orbits on the void have also been measured.
Energy approximants and perturbation theory for screened Coulomb potentials
Authors: Lai C. S. , Kiang D.
Published: March 2010

By applying the Hellmann–Feynman theorem and the virial theorem to screened Coulomb potentials, the energy is shown to be expressible in terms of an integral. Making use of the Padé approximant for the integrand, the modified [3,4] energy approximant obtained speeds up to the convergence of the energy perturbation series. The prediction of the modified [3,4] energy approximant for an electron in the Yukawa potential is in good agreement with that of numerical integration.
The electronic emission spectrum of triatomic hydrogen. I. Parallel bands of H3 and D3 near 5600 and 6025 Å
Authors: Dabrowski I. , Herzberg G.
Published: March 2010

A spectrum of triatomic hydrogen and deuterium was first discovered by means of an emission band with diffuse rotational structure near 5600 Å. An additional band of similar but much better resolved structure was subsequently observed near 6025 Å. The detailed analysis of these two bands for both H3 and D3 is described in this paper. Both bands are [Formula: see text] bands of a symmetric top; their structure establishes beyond doubt that triatomic hydrogen has a D3h structure in its Rydberg states. The molecular constants in upper and lower states are close to those in the ground state of H3+ (or D3+) in accordance with the assumption that these states are Rydberg states in which a single electron moves around a H3+ or D3+ core. The predicted states of such a Rydberg electron in a field of D3h symmetry account very well for the observed electronic states, both those involved in the [Formula: see text] bands described here and those involved in the [Formula: see text] bands to be discussed in subsequent papers of this series. The lowest state of the Rydberg electron 2p2E′ is unstable and dissociates to H2 + H in their ground states. It is this state that causes predissociation in the two lower states 2s2A1′and 2p2A2″ of the two [Formula: see text] bands here under discussion. The predissociation of 2s2A1′ is vibronically allowed and fairly strong such that all lines have widths of about 7 cm−1 for D3 and 30 cm−1 for H3. The predissociation of the 2p2A2″ state is vibronically forbidden and occurs only on account of ro-vibronic interaction. H3+ ions are assumed to be present in the interstellar medium. When they recombine with electrons they must necessarily emit the spectra described in this series of papers.
The electronic emission spectrum of triatomic hydrogen. II. The perpendicular bands near 7100 Å
Authors: Herzberg G. , Watson J. K. G.
Published: March 2010

The strongest emission bands of H3 and D3 near 7100 Å are shown to be [Formula: see text] bands even though of a somewhat unusual structure. Because of the large width of the lines (the same as those of the 5600 Å [Formula: see text] bands) the only method of analysis is by model bands whose parameters are changed until the best fit between observed and calculated spectrum is obtained. As expected on the basics of the line width the lower state is found to be identical with that of the 5600 Å band, i.e., 2s2A1′, while the upper state is 3p2E′. The band structure of a [Formula: see text] band depends strongly on the value of ζ, the electronic angular momentum. When as in the present case ζ is close to 1, pseudo-branches with a constant N – K form the most characteristic features of the [Formula: see text] band. The ζ value determined here for the 3p2E′ state of D3 is 0.8775 which is very close to the ab initio value of King and Morokuma after the latter has been corrected for quenching by the zero-point vibration as a result of Jahn–Teller interaction. In addition the band structure shows clearly the effects of Λ-type doubling and Λ-type resonance which is made especially large by Jahn–Teller distortion. The final B0 value of D3 in the 3p2E′ state, i.e., B0 = 21.16 cm−1, is smaller than the predicted value (21.61 cm−1) for the ground state of D3+ suggesting that the 3pe′ orbital is anti-bonding in agreement with the predictions of King and Morokuma.
GENERALIZED ZARISKI–VAN KAMPEN THEOREM AND ITS APPLICATION TO GRASSMANNIAN DUAL VARIETIES
Authors: SHIMADA ICHIRO
Published: March 2010

We formulate and prove a generalization of Zariski–van Kampen theorem on the topological fundamental groups of smooth complex algebraic varieties. As an application, we prove a hyperplane section theorem of Lefschetz–Zariski–van Kampen type for the fundamental groups of the complements to the Grassmannian dual varieties.
MODULI SPACE OF STABLE MAPS TO PROJECTIVE SPACE VIA GIT
Authors: KIEM YOUNG-HOON , MOON HAN-BOM
Published: March 2010

We compare the Kontsevich moduli space [Formula: see text] of stable maps to projective space with the quasi-map space ℙ( Sym d(ℂ2) ⊗ ℂn)//SL(2). Consider the birational map [Formula: see text] which assigns to an n tuple of degree d homogeneous polynomials f1, …, fn in two variables, the map f = (f1 : ⋯ : fn) : ℙ1 → ℙn-1. In this paper, for d = 3, we prove that [Formula: see text] is the composition of three blow-ups followed by two blow-downs. Furthermore, we identify the blow-up/down centers explicitly in terms of the moduli spaces [Formula: see text] with d = 1, 2. In particular, [Formula: see text] is the SL(2)-quotient of a smooth rational projective variety. The degree two case [Formula: see text], which is the blow-up of ℙ( Sym 2ℂ2 ⊗ ℂn)//SL(2) along ℙn-1, is worked out as a preliminary example.
PSEUDOSPIN SYMMETRY IN DEFORMED NUCLEI WITH AXIALLY-SYMMETRIC HARMONIC OSCILLATOR POTENTIAL
Authors: SETARE M. R. , NAZARI Z.
Published: March 2010

We examine the pseudospin symmetry in deformed nuclei with axially-symmetry and obtain the eigenfunctions and energy equation for the case of axially-symmetric harmonic oscillator potential in the Dirac equation.
PATHWAYS TO TESTABLE LEPTOGENESIS
Authors: GU PEI-HONG , SARKAR UTPAL
Published: March 2010

In the conventional seesaw models of neutrino masses, leptogenesis occurs at a very high scale. Three approaches have been discussed in the literature to lower the scale of leptogenesis making them testable: mass degeneracy, hierarchy of couplings and three-body decays. We advocate yet another approach to a testable leptogenesis, whereby the decaying particles could go out of equilibrium at an accessible scale due to kinematics, although their couplings to the decay products are larger for generating a desired CP asymmetry. We demonstrate this new possibility for the testable leptogenesis in a two-Higgs doublet model where the neutrino masses originate from a one-loop diagram.
A NOVEL FRACTIONAL-ORDER HYPERCHAOTIC SYSTEM AND ITS CIRCUIT REALIZATION
Authors: LIU CHONGXIN , LU JUNJIE
Published: March 2010

In this paper, a fractional-order hyperchaotic system evolved from Liu system is proposed. Based on the theory of fractional calculus, a novel circuit diagram is designed for hardware implementation of the fractional-order hyperchaotic Liu system. Furthermore, implementation results reveal that hyperchaos can be generated in the hyperchaotic Liu system with the system order as low as 3.6 and numerical analysis results demonstrate that the lowest order of the fractional-order Liu system is 0.4.
CHAOS SYNCHRONIZATION OF AN UNCERTAIN LORENZ HYPERCHAOTIC SYSTEM VIA A MODIFIED ADAPTIVE METHOD
Authors: WU XIANGJUN , FENG DONGDONG , CHEN GUANRONG
Published: March 2010

A modified adaptive control scheme for synchronization of an uncertain Lorenz hyperchaotic system is proposed. Based on the Lyapunov stability theory, the sufficient condition for the synchronization is analyzed and proved theoretically. With the condition derived, parameter identification and synchronization of the Lorenz hyperchaotic system with all the unknown system parameters can be achieved simultaneously. Numerical simulations are presented to illustrate the effectiveness of the proposed synchronization scheme.
SYNTHESIS, GRAIN GROWTH, Cu-DOPING, AND MAGNETIC PROPERTIES OF NANOCRYSTALLINE Ni–Zn FERRITE
Authors: JALALY MAISAM , ENAYATI MOHAMMAD-HOSEIN , KAMELI PARVIZ , KARIMZADEH FATHOLLAH
Published: March 2010

Nanostructured powder of Ni – Zn ferrite was directly produced by high-energy ball milling of stoichiometric mixture of ZnO , NiO , and Fe 2 O 3 powders. X-ray powder diffractometry, scanning electron microscopy, annealing, treatment, and vibrating sample magnetometer were used to investigate the structural, chemical, and magnetic aspects of Ni 0.5 Zn 0.5 Fe 2 O 4 compound. The crystallite size of final product after 60 h of ball milling time was estimated to be 17 nm. Heat treatment of ball-milled Ni – Zn ferrite was performed to study the thermal behavior of ferrite. The effect of copper doping on structure and magnetic properties of Ni – Zn ferrite was also studied. The results showed that the Zn replacement with Cu led to a decrease of magnetization.
QUANTUM INFORMATION TRANSFER IN A TWO-PARALLEL SPIN-CHAIN CHANNEL WITH INTERNAL AND EXTERNAL EFFECTS
Authors: LIU JIA , ZHANG GUO-FENG , CHEN ZI-YU
Published: March 2010

With the effects of Dzialoshinski–Moriya interaction and external magnetic field, the entanglement transfer has been investigated in a parallel spin-chain system. Our results imply that the perfect transfer can be realized at some special times, and the transfer time can be greatly condensed with the rising of the spin-orbit coupling strength. The entanglement sudden death phenomenon is sensitive to the initial condition. In addition, due to the application of magnetic field on the channel spins, the reliability and efficiency of the transmission are greatly challenged.
RAMAN STUDY OF VANADIUM-DOPED TITANIA NANOPOWDERS SYNTHESIZED BY SOL-GEL METHOD
Authors: ŠĆEPANOVIĆ M. , AŠKRABIĆ S. , GRUJIĆ-BROJČIN M. , GOLUBOVIĆ A. , DOHČEVIĆ-MITROVIĆ Z. , MATOVIĆ B. , POPOVIĆ Z. V.
Published: March 2010

Pure titania ( TiO 2) nanopowders and TiO 2 doped with 10 mol % of vanadium ions ( V 3+) are synthesized by sol-gel method. The dependence of structural characteristics of nanopowders on synthesis conditions is investigated by X-ray diffraction and Raman spectroscopy. Very intensive modes observed in Raman spectra of all nanopowders are assigned to anatase phase of TiO 2. Additional Raman modes of extremely low intensity which can be related to the presence of small amount of brookite amorphous phase are observed in pure TiO 2 nanopowders. In V -doped nanopowders anatase was the only TiO 2 phase detected. The variations in duration and heating rate of calcination influence slightly the Raman spectra of pure TiO 2, but have a great impact on Raman modes of anatase, as well as the additional Raman modes related to the presence of vanadium oxides in V -doped samples.
ON THE SKUTTERUDITE Pt4Sn4.4Sb7.6
Authors: ROGL GERDA , GRYTSIV ANDRIY , ROGL PETER , BAUER ERNST , KRIEGISCH MARTIN , PUCHEGGER STEPHAN , ZEHETBAUER MICHAEL
Published: March 2010

Pt 4 Sn 4.4 Sb 7.6 ( a = 9.3304(2) Å, space group [Formula: see text] ) is an unfilled skutterudite member of the solid solution Sn x Pt 4 Sn y Sb 12- x . In contrast to Sn x Ni 4 Sn y Sb 12- y and Sn x Pt 4 Sn y Sb 12- x no Sn could be found in the 2 a sites of the Sn / Sb framework. Physical properties have been data for Ni 4 Sn 3 Sb 9 and Ni 4 Sn 3.5 Sb 8.5. Resistivity measurements for Pt 4 Sn 4.4 Sb 7.6 reveal a temperature dependent crossover from metallic to semiconducting behaviour connected with a corresponding change from negative to positive thermopower at 30 K. Vicker's hardness, thermal expansion and elastic moduli compare well with values of other Sb - investigated in the temperature range from 4.2 K to 800 K and have been compared with based skutterudites.
NANO ALPHA-ALUMINA POWDERS AND DENSE CERAMICS
Authors: KARAGEDOV G. R. , LYAKHOV N. Z.
Published: March 2010

Three various α-alumina nanopowders have been characterized and their behavior in dry uniaxial pressing followed by pressureless sintering in air investigated. Nearly full dense ceramic material has been obtained at no more than 1300°C and its grain size evaluated by scanning electron microscopy and X-ray line profile analysis as being about 200 nm. The most suitable powder for low temperature sintering was reported to be that consisting of aggregates strong enough to enable their dense packing during the die filling and early period of pressure rise but capable of being destroyed further at final stage of compaction. Several dense samples with grain size on the level of 100 nm and less have been shown to be available at 1150-1200°C if a proper molding technique would be developed.
ANISOTROPIC GOLD NANOCRYSTALS: SYNTHESIS AND CHARACTERIZATION
Authors: STIUFIUC R. , TODERAS F. , IOSIN M. , STIUFIUC G.
Published: March 2010

In this letter we report on successful preparation and characterization of anisotropic gold nanocrystals bio-synthesized by reduction of aqueous chloroaurate ions in pelargonium plant extract. The nanocrystals have been characterized by means of Transmission Electron Microscopy (TEM), UV-VIS absorption spectroscopy and tapping mode atomic force microscopy (TM-AFM). Using these investigation techniques, the successful formation of anisotropic single nanocrystals with the preferential growth direction along the gold (111) plane has been confirmed. The high detail phase images could give us an explanation concerning the growth mechanism of the nanocrystals.
LASER PROPULSION FOR TRANSPORT IN WATER ENVIRONMENT
Authors: HAN BING , SHEN ZHONG-HUA , LU JIAN , NI XIAO-WU
Published: March 2010

Problems that cumber the development of the laser propulsion in atmosphere and vacuum are discussed. Based on the theory of interaction between high-intensity laser and materials, such as air and water, it is proved that transport in a water environment can be impulsed by laser. The process of laser propulsion in water is investigated theoretically and numerically. It shows that not only the laser induced plasma shock wave can be used, but also the laser-induced bubble oscillation shock waves and the pressure induced by the collapsing bubble can be used. Many experimental results show that the theory and the numerical results are valid.
INFINITE NETWORKS OF IDENTICAL CAPACITORS
Authors: ASAD J. H. , HIJJAWI R. S. , SAKAJI A. J. , KHALIFEH J. M.
Published: March 2010

The capacitance between the origin and any other lattice site in an infinite square lattice of identical capacitors each of capacitance C is calculated. The method is generalized to infinite Simple Cubic (SC) lattice of identical capacitors each of capacitance C. We make use of the superposition principle and the symmetry of the infinite grid.
AMCLM: ADAPTIVE MULTI-SERVICES CROSS-LAYER MAC PROTOCOL FOR IEEE 802.11 NETWORKS
Authors: BEN-OTHMAN JALEL , MOKDAD LYNDA , BOUAM SOUHEILA
Published: March 2010

In wireless networks, the radio link vulnerability attributed to effects such as noise, interference, free-space loss, shadowing and multipath fading, must be considered. MAC protocols developed for these networks do not take into account these perturbations. It was shown, in the literature, that 802.11 suffers from what is called 'the 802.11 anomaly'. This anomaly concerns two aspects: all nodes throughput, in a 802.11 network, falls to the worst one of all nodes and the bandwidth will be divided by the number of the mobile nodes of the network. In order to improve the quality of service of a BSS (Basic Service Set) and to solve 802.11 anomaly, Cross-layer approaches are developed. These approaches are especially based on information given by the Physical layer. In this study we propose a new cross-layer scheme: AMCLM (Adaptive Multi-services Cross-Layer MAC). The goal of this protocol is to improve the Quality-of-Service (QoS) of Mobile Nodes (MNs) connected in a BSS by a temporary disassociation of the ones for which the SNR (Signal to Noise Ratio) is under a defined threshold. In this way, the network's throughput is improved. Our approach aims to improve global networks QoS by unselfishness decisions of nodes. In order to show the benefit of our method, a performance evaluation of this protocol has been made. We have built the discrete Markov Chain associated to the behavior of AMCLM protocol to analyze the throughput of mobile nodes connected to the BSS.
HIERARCHICAL REPLICATION TECHNIQUES TO ENSURE CHECKPOINT STORAGE RELIABILITY IN GRID ENVIRONMENT
Authors: BOUABACHE FATIHA , HERAULT THOMAS , FEDAK GILLES , CAPPELLO FRANCK
Published: March 2010

An efficient and reliable fault tolerance protocol plays a key role in High Performance Computing. Rollback recovery is the most common fault tolerance technique used in High Performance Computing and especially in MPI applications. This technique relies on the reliability of the checkpoint storage. Most of the rollback recovery protocols assume that the checkpoint servers machines are reliable. However, in a grid environment any unit can fail at any moment, including components used to connect different administrative domains. Such failures lead to the loss of a whole set of machines, including the more reliable machines used to store the checkpoints in this administrative domain. Thus it is not safe to rely on the high Mean Time Between Failures of specific machines to store the checkpoint images.

This paper introduces a new coordinated checkpoint protocol, which tolerates checkpoint server failures and clusters failures, and ensures a checkpoint storage reliability in a grid environment. To provide this reliability the protocol is based on a replication process. We propose new hierarchical replication strategies that exploit the locality of checkpoint images in order to minimize inter-cluster communication.

We evaluate the effectiveness of our two hierarchical replication strategies through simulations against several criteria such as topology and scalability.
ADAPTIVE DATA DISSEMINATION IN MOBILE SENSOR NETWORKS
Authors: KINALIS ATHANASIOS , NIKOLETSEAS SOTIRIS
Published: March 2010

Motivated by emerging applications, we consider sensor networks where the sensors themselves (not just the sinks) are mobile. Furthermore, we focus on mobility scenarios characterized by heterogeneous, highly changing mobility roles in the network. To capture these high dynamics of diverse sensory motion we propose a novel network parameter, the mobility level, which, although simple and local, quite accurately takes into account both the spatial and speed characteristics of motion. We then propose adaptive data dissemination protocols that use the mobility level estimation to optimize performance, by basically exploiting high mobility (redundant message ferrying) as a cost-effective replacement of flooding, e.g. the sensors tend to dynamically propagate less data in the presence of high mobility, while nodes of high mobility are favored for moving data around. These dissemination schemes are enhanced by a distance-sensitive probabilistic message flooding inhibition mechanism that further reduces communication cost, especially for fast nodes of high mobility level, and as distance to data destination decreases. Our simulation findings demonstrate significant performance gains of our protocols compared to non-adaptive protocols, i.e. adaptation increases the success rate and reduces latency (even by 15%) while at the same time significantly reducing energy dissipation (in most cases by even 40%). Also, our adaptive schemes achieve significantly higher message delivery ratio and satisfactory energy-latency trade-offs when compared to flooding when sensor nodes have limited message queues.
SECURE ANONYMOUS COMMUNICATION FOR WIRELESS SENSOR NETWORKS BASED ON PAIRING OVER ELLIPTIC CURVES
Authors: MIZANUR RAHMAN SK. MD. , EL-KHATIB KHALIL
Published: March 2010

The nature of wireless communication makes it susceptible to a number of security threats, disclosing the identities of the communicating parties in the network. By revealing the identity of nodes in the network, outside parties can setup severe targeted attacks on specific nodes. Such targeted attacks are more harmful to sensor networks as sensing nodes (sensors) have limited computing and communication power prohibiting them from using robust security mechanisms. Anonymous communication is one of the key primitives for ensuring the privacy of communicating parties in a group or network. In this paper, we propose a novel secure anonymous communication protocol based on pairing over elliptic curves for wireless sensor networks (WSNs). Using this protocol, only the legitimate nodes in the sensor network can authenticate each other without disclosing their real identities. The proposed protocol is extremely efficient in terms of key storage space and communication overhead. Security analysis of our protocol shows that it provides complete anonymity for communicating nodes. The analysis also shows that the proposed protocol is robust against a number of attacks including the masquerade attack, wormhole attack, selective forwarding attack and message manipulation attack.
BIO-INSPIRED ALGORITHMS FOR MOBILITY MANAGEMENT
Authors: TAHERI JAVID , ZOMAYA ALBERT Y.
Published: March 2010

This work reviews a number of bio-inspired algorithms and examines their suitability for solving the location management problem by using the paging cell and location area schemes. A comparison is performed using three test networks using realistic user movement patterns. The results provide new insight into the mobility management problem that can influence the design of future wireless networks.
DETECTION AND IDENTIFICATION OF ANOMALIES IN WIRELESS MESH NETWORKS USING PRINCIPAL COMPONENT ANALYSIS (PCA)
Authors: ZAIDI ZAINAB R. , HAKAMI SARA , MOORS TIM , LANDFELDT BJORN
Published: March 2010

Anomaly detection is becoming a powerful and necessary component as wireless networks gain popularity. In this paper, we evaluate the efficacy of PCA based anomaly detection for wireless mesh networks (WMN). PCA based method [1] was originally developed for wired networks. Our experiments show that it is possible to detect different types of anomalies, such as Denial-of-service (DoS) attack, port scan attack [1], etc., in an interference prone wireless environment. However, the PCA based method is found to be very sensitive to small changes in flows causing non-negligible number of false alarms. This problem prompted us to develop an anomaly identification scheme which automatically identifies the flow(s) causing the detected anomaly and their contributions in terms of number of packets. Our results show that the identification scheme is able to differentiate false alarms from real anomalies and pinpoint the culprit(s) in case of a real fault or threat. Moreover, we also found that the threshold value used in [1] for distinguishing normal and abnormal traffic conditions is based on assumption of normally distributed traffic which is not accurate for current network traffic which is mostly self-similar in nature. Adjusting the threshold also reduced the number of false alarms considerably. The experiments were performed over an 8 node mesh testbed deployed in a suburban area, under different realistic traffic scenarios. Our identification scheme facilitates the use of PCA based method for real-time anomaly detection in wireless networks as it can filter the false alarms locally at the monitoring nodes without excessive computational overhead.
DEPPDB — DNA ELECTROSTATIC POTENTIAL PROPERTIES DATABASE: ELECTROSTATIC PROPERTIES OF GENOME DNA
Authors: OSYPOV ALEXANDER A. , KRUTININ GLEB G. , KAMZOLOVA SVETLANA G.
Published: March 2010

The electrostatic properties of genome DNA influence its interactions with different proteins, in particular, the regulation of transcription by RNA-polymerases. DEPPDB — DNA Electrostatic Potential Properties Database — was developed to hold and provide all available information on the electrostatic properties of genome DNA combined with its sequence and annotation of biological and structural properties of genome elements and whole genomes. Genomes in DEPPDB are organized on a taxonomical basis. Currently, the database contains all the completely sequenced bacterial and viral genomes according to NCBI RefSeq. General properties of the genome DNA electrostatic potential profile and principles of its formation are revealed. This potential correlates with the GC content but does not correspond to it exactly and strongly depends on both the sequence arrangement and its context (flanking regions). Analysis of the promoter regions for bacterial and viral RNA polymerases revealed a correspondence between the scale of these proteins' physical properties and electrostatic profile patterns. We also discovered a direct correlation between the potential value and the binding frequency of RNA polymerase to DNA, supporting the idea of the role of electrostatics in these interactions. This matches a pronounced tendency of the promoter regions to possess higher values of the electrostatic potential.
INTERACTION OF ANTIBODIES WITH AROMATIC LIGANDS: THE ROLE OF π-STACKING
Authors: ARZHANIK VLADIMIR , SVISTUNOVA DARJA , KOLIASNIKOV OLEG , EGOROV ALEXEY M.
Published: March 2010

Antibodies are responsible for antigen recognition in vertebrate organisms. Practically any molecule can be bound by antibodies. In this work structures of 73 complexes of antibodies with small antigens were taken from PDB database and compared. The main epitope of studied ligands was an aromatic ring. Antibodies bound it with a deep cavity, lying between complementary determining regions (CDR) H3 and L3 and formed by aromatic residues. In most cases the aromatic ring of ligand was placed parallel to one or two aromatic sidechains of binding site at 3.5-4 Angstrom distance. This disposition of aromatic rings is a sign of the presence of π-stacking. It was found that small ligands with aromatics area percentage > 36% predominantly form π-stacking interaction with antibodies. Most often this interaction was observed for residues in positions H33, H95, L32 and L93.
XPS Study of Chemical Changes on the La/Ce Treated Surface of A361 Aluminium Alloy Exposed to Air at Temperatures up to 500∘C
Authors: Pardo A. , Feliú S. , Merino M. C. , Arrabal R. , Matykina E.
Published: March 2010

The chemical changes that take place on the rare earth treated surface of the A361 aluminium alloy exposed to air at temperatures between 100 and 500∘C have been examined using X‐ray photoelectron spectroscopy (XPS). The most notable features discussed in this work are the disappearance of Mg and Si signals at the tested temperatures and disappearance of the Ce signal at temperatures of 400–500∘C. The biphasic microstructure of the A361 alloy, constituted by close to 12 wt% Si and the Al matrix, plays an important role in many of the results obtained. The notable growth of aluminium oxide across the conversion coating in the case of the Ce‐treated surface is related to the structural transformation experienced by the cerium oxide coating at 400–500∘C.
A Discrete-Time Downsampling FIR Filter for Windowed Integration Samplers
Authors: Raviprakash Karthik , Kulkarni Mandar , Chen Xi , Hoyos Sebastian , Sadler Brian M.
Published: March 2010

A novel technique to reduce die area on a discrete-time
sinc2↓2 filter for charge sampling is proposed. An SNR comparison of the conventional and the proposed topology reveals that the new technique saves 25% die area occupied by the sampling capacitors of the filter. The idea is also extended to implement higher downsampling factors, and greater percentage of area is saved as the downsampling factor is increased. The proposed filter also has the topological advantage over previously reported works of allowing the designers to use active integration to charge the capacitance, which is critical in obtaining high linearity.
Red Blood Cell Transfusion Independence Following the Initiation of Iron Chelation Therapy in Myelodysplastic Syndrome
Authors: Badawi Maha A. , Vickars Linda M. , Chase Jocelyn M. , Leitch Heather A.
Published: March 2010

Iron chelation therapy is often used to treat iron overload in patients requiring transfusion of red blood cells (RBC). A 76-year-old man with MDS type refractory cytopenia with multilineage dysplasia, intermediate-1 IPSS risk, was referred when he became transfusion dependent. He declined infusional chelation but subsequently accepted oral therapy. Following the initiation of chelation, RBC transfusion requirement ceased and he remained transfusion independent over 40 months later. Over the same time course, ferritin levels decreased but did not normalize. There have been eighteen other MDS patients reported showing improvement in hemoglobin level with iron chelation; nine became transfusion independent, nine had decreased transfusion requirements, and some showed improved trilineage myelopoiesis. The clinical features of these patients are summarized and possible mechanisms for such an effect of iron chelation on cytopenias are discussed.
Effect of Antenna Mutual Coupling on MIMO Channel Estimation and Capacity
Authors: Liu Xia , Bialkowski Marek E.
Published: March 2010

This paper describes investigations into the antenna mutual coupling (MC) effect on channel estimation and capacity of a multiple-input multiple-output (MIMO) wireless communication system. The presented investigations close the gap existing in the previous works which assessed the effect of mutual coupling on MIMO capacity under the assumption of availability of perfect channel state information (CSI) at the receiver. The new approach assumes that the perfect CSI is not available due to channel estimation errors. The investigations are carried out for different spacing between array antenna elements producing a varying effect of mutual coupling on the channel estimation and the resulting MIMO channel capacity.
Multiple Solutions of Quasilinear Elliptic Equations in ℝN
Authors: Lin Huei-li
Published: March 2010

Assume that Q is a positive continuous function in ℝN and satisfies some suitable conditions. We prove that the quasilinear elliptic equation −Δpu+|u|p−2u = Q(z) | u|q−2u in ℝN admits at least two solutions in ℝN (one is a positive ground‐state solution and the other is a sign‐changing solution).
Recognition of Depression and Anxiety among Elderly Colorectal Cancer Patients
Authors: Zhang Amy Y. , Cooper Gregory S.
Published: March 2010

This study investigated the ICD-9 diagnostic rates of depressive and anxiety disorders, including major depression, neurotic depression, adjustment disorder with depressed mood, depressive disorder NOS (not elsewhere classified), and anxiety states, among elderly Medicare beneficiaries (age ≥ 65) who received a colorectal cancer diagnosis between 1998 and 2002 in U.S. The Seer-Medicare data, representing 14–25% of the U.S. population, was used to examine ICD-9 diagnostic rates of depressive and anxiety disorders among 56,182 colorectal cancer outpatients and 265,382 noncancer outpatients, respectively. The findings show that the ICD-9 diagnoses ranged from 1.5% to 1.8% for depressive disorders and 0.8% to 1.2% for anxiety states in the colorectal cancer outpatients, and from 2% to 2.5% for depressive disorders and 1.1% to 1.5% for anxiety states in the noncancer outpatients over five years. More than 70% of colorectal cancer outpatients with a depressive diagnosis were diagnosed for depressive disorder NOS. The findings suggest that the difficulty in recognizing depressive symptoms in colorectal cancer patients may contribute in part to the low ICD-9 diagnostic rates of depressive disorders. They call for research attention to the investigation of depressive symptoms for improving the recognition and treatment in this patient population.
Acanthopanax koreanumFruit Waste Inhibits Lipopolysaccharide-Induced Production of Nitric Oxide and Prostaglandin E2in RAW 264.7 Macrophages
Authors: Yang Eun-Jin , Moon Ji-Young , Lee Jung-Soon , Koh Jaesook , Lee Nam Ho , Hyun Chang-Gu
Published: March 2010

TheAcanthopanax koreanumfruit is a popular fruit in Jeju Island, but the byproducts of the alcoholic beverage prepared using this fruit are major agricultural wastes. The fermentability of this waste causes many economic and environmental problems. Therefore, we investigated the suitability of usingA. koreanumfruit waste (AFW) as a source of antiinflammatory agents. AFWs were extracted with 80% EtOH. The ethanolic extract was then successively partitioned with hexane, , EtOAc, BuOH, and water. The results indicate that the fraction (100 g/mL) of AFW inhibited the LPS-induced nitric oxide (NO) and prostaglandin () production in RAW 264.7 cells by 79.6% and 39.7%, respectively. These inhibitory effects of the fraction of AFWs were accompanied by decreases in the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins and iNOS and COX-2 mRNA in a dose-dependent pattern. The fraction of AFWs also prevented degradation of IB- in a dose-dependent manner. Ursolic acid was identified as major compound present in AFW, and extracts by high performance liquid chromatography (HPLC). Furthermore using pure ursolic acid as standard and by HPLC, AFW and extracts was found to contain 1.58 mg/g and 1.75 mg/g, respectively. Moreover, we tested the potential application of AFW extracts as a cosmetic material by performing human skin primary irritation tests. In these tests, AFW extracts did not induce any adverse reactions. Based on these results, we suggest that AFW extracts be considered possible anti-inflammatory candidates for topical application.
Arterial Cord Blood Lactate at Birth Correlates with Duration of Pushing Efforts
Authors: Dessolle Lionel , Lebrec Jeremie , Daraï Emile
Published: March 2010

Objective: To evaluate the impact of the duration of pushing efforts on arterial cord blood lactate values. Methods: This was a prospective observational study of 124 consecutive normal vaginal deliveries in a tertiary teaching hospital. Arterial cord blood lactate was determined immediately at birth with a test strip method. Univariate and multivariate analyses were performed to check for clinical determinants of lactate levels. The main measure was lactate according to the duration of pushing efforts. Results: Arterial cord lactates increased significantly and were strongly correlated with the duration of pushing efforts, independent of gestational age and birthweight. Women pushing for more than 20 min had higher arterial cord blood lactates (4.9 ± 1.4 vs. 3.3 ± 1.16 mM, respectively) and a higher rate of lactates >6 mM (18 vs. 3%) than those pushing for less than 20 min. Conclusion: At normal delivery, arterial cord blood lactates increase significantly with the duration of pushing efforts. Pushing for more than 20 min is associated with an increased risk of metabolic acidosis in the neonate. Further studies are required to evaluate the clinical significance of these observations.
Optical Properties of Human Amniotic Fluid: Implications for Videofetoscopic Surgery
Authors: Steigman Shaun A. , Kunisaki Shaun M. , Wilkins-Haug Louise , Takoudes Tamara C. , Fauza Dario O.
Published: March 2010

Objective: Videofetoscopy typically demands the substitution of oft-turbid amniotic fluid with clear crystalloid. This maneuver can be cumbersome and may lead to complications. We sought to determine the optical properties of the amniotic fluid, as a pre-requisite for optimizing video image processing during videofetoscopy and eventually avoid amniotic fluid replacement. Methods: Human amniotic fluid samples (n = 21) were procured at 19–36 weeks of gestation. Optical refraction and reflection indices were recorded as percentages of light transmission through the fluid using an integrated spectrometer covering wavelengths of 400–950 nm, with 1.0 nm resolution. Statistical analysis was by one-way ANOVA (p < 0.05). Results: Peak optical refraction fell within a relatively limited window of the near-infrared spectrum, at 848.1 ± 52.3 nm, regardless of gestational age or overall light absorbance. Within the visible spectrum, transmission was highest at the highest wavelengths. A statistically significant inverse relationship existed between gestational age and overall light transmission. Light reflection was negligible in all samples. Conclusions: Light transmission through amniotic fluid is optimal in the near-infrared spectrum and at the highest visible wavelengths, regardless of gestational age. Overall light transmission through amniotic fluid decreases throughout gestation. The light source and camera of videofetoscopy systems should be designed accordingly, possibly obviating the need for routine intraoperative amniotic fluid exchange.
Tricuspid Valve Dysplasia with Severe Tricuspid Regurgitation: Fetal Pulmonary Artery Size Predicts Lung Viability in the Presence of Small Lung Volumes
Authors: Nathan A.T. , Marino B.S. , Dominguez T. , Tabbutt S. , Nicolson S. , Donaghue D.D. , Spray T.L. , Rychik J.
Published: March 2010

Congenital tricuspid valve disease (Ebstein’s anomaly, tricuspid valve dysplasia) with severe tricuspid regurgitation and cardiomegaly is associated with poor prognosis. Fetal echocardiography can accurately measure right atrial enlargement, which is associated with a poor prognosis in the fetus with tricuspid valve disease. Fetal lung volumetric assessments have been used in an attempt to predict viability of fetuses using ultrasonogram and prenatal MRI. We describe a fetus with tricuspid dysplasia, severe tricuspid regurgitation, right atrial enlargement and markedly reduced lung volumes. The early gestational onset of cardiomegaly with bilateral lung compression raised the possibility of severe lung hypoplasia with decreased broncho-alveolar development. Use of fetal echocardiography with measurement of pulmonary artery size combined with prenatal MRI scanning of lung volumes resulted in an improved understanding of this anomaly and directed the management strategy towards a successful Fontan circulation.
Concordance for Bilateral Congenital Diaphragmatic Hernia in a Monozygotic Dichorionic Twin Pair – First Clinical Report
Authors: Machado A.P. , Ramalho C. , Portugal R. , Brandão O. , Carvalho B. , Carvalho F. , Matias A. , Montenegro N.
Published: March 2010

The authors present a clinical case of concordance for bilateral congenital diaphragmatic hernia in a monozygotic twin pair diagnosed in the early second trimester.
Umbilical Arterial Necrotic Vasculopathy Associated with Fetal Ascites
Authors: Rossi Giuliana , Cosmi Erich , Trevisanuto Daniele , Cappellari Ambra , Andrisani Alessandra , Visentin Silvia , Chiarelli Silvia , Zanardo Vincenzo
Published: March 2010

Immune and nonimmune neonatal ascites may be part of hydrops fetalis or may be an isolated finding. However, a significant percentage of nonimmune ascites do not have an identifiable pathogenesis and are considered idiopathic. We report a case of fetal ascites and umbilical arterial necrotic vasculopathy, an association not previously described.
Two Case Reports of Columnar Dyskeratosis, an Unusual Keratinisation Disorder
Authors: Pock Lumír , Štork Jiří
Published: March 2010

Keratinisation disorders with distinctive histopathological patterns are few in number. We describe two men with unusual dermatosis, characterised by a distinctive pattern of focal dyskeratosis. Both men suffered from generalised dermatosis formed by verrucous red-brown plaques. Repeated skin biopsies showed the same histopathological pattern with foci of vertically oriented dyskeratotic cells. The dyskeratotic cells on the level of the stratum spinosum and granulosum were positive for AE1/AE3, CK-HW, CK-LS and CK116 immunostaining. PCR for HPV was negative. The similar clinical appearance of skin lesions in both patients together with their identical histopathological pictures seems to represent a unique clinicopathological condition that we believe is best described by the term ‘columnar dyskeratosis’.