bluuebunny/crossref_metadata_2025 huggingface dataset:
Intersphincteric resection with partial removal of external anal sphincter for low rectal cancer
Authors: Shelygin Y.A. , Vorobiev G.I. , Pikunov D.YU. , Markova E.V. , Djhanaev Y.A. , Fomenko O.YU.
Published: November 2008

Abdominoperineal resection (APR) remains the standard procedure for rectal cancer located within 0.5 cm from dentate line (DL). In this study, we present a new type of restorative surgery: intersphincteric resection with partial removal of external anal sphincter (EAS) and anorectal reconstruction for ultra low rectal cancer. Between March 2003 and May 2008 fifty patients (28 males, aged between 39 and 71) were operated on for ultra low rectal cancer uT2-3N0M0 with partial preservation of EAS and total anorectal reconstruction (smoothmuscle neosphincter and colonic pouch). A protective stoma was performed in all cases. Functional outcome and quality of life were recorded at 3,6,12,18,24 months after stoma closure using Wexner score and FIQL respectively. Anal manometry, vectrum volumetry and myography data were taken as well. Results. Postoperative complications developed in 2 patients, but no secondary surgery was required. Carcinomas were staged as pT2 (n=14) and pT3 (n=36). The distal clearan - ce was 2.00.4(range 1.5-2.8)cm, lateral clearance was 0.80.3(range 0.2-1.4)cm. After a median follow-up of 24 (range 2-61) months, 2 local recurrences were occurred and salvaged by APR. Contractive activity of saved elements of EAS improved with a course of time and squeezing anal pressure increased as well. Perfect functional outcome was achieved in 25 of 34 patients at 12 months after stoma closure, and all the patients were satisfied with procedure. Good functional results of suggested surgery seems to be an acceptable alternative to APR with permanent stoma in selected patients.
Could the surgeon trust to radiotherapy help in rectal cancer?
Authors: Valentini V. , Gambacorta M.A. , Barba M.C.
Published: November 2008

When the surgeon analyzes the ongoing literature on the evidence of the neoadjuvant approaches to rectal cancer finds a true paradox: from one side they seem to offer a relative less relevant contribute through the time, in fact whereas in the Swedish trial preoperative radiation yielded a significant improvement of local control and survival, after the introduction of TME the contribution of preoperative chemoradiation is relegate to local control with no or poor influence on survival, even if the absolute 5-year survival rate moved from 40% of the ?70 to 60-65% of the latest years1-3. From other side the growing evidence of an incidence of pCR approaching to 30%4, seems to identify a subset of patients with more favorable prognosis to neoadjuvant treatments5-6. Furthermore, the overall evidence that 30- 35% of rectal cancer patients treated with multimodality therapy still die from cancer namely by distant metastases in spite of the 4-8 % of absolute benefit of adjuvant 5Fu based adjuvant chemotherapy7, seems to vanish the efforts of the further optimization of the local treatments (surgery and radiotherapy) and of the ongoing modality of delivery the chemotherapeutic agents. We would like to address the main evidences from the literature and the main uncertainties that the surgeon could face to propose a combined treatment to his rectal cancer patient.
Intestinal pseudoobstruction
Authors: Rabau O. , Tulchinsky H. , Rabau M.
Published: November 2008

Intestinal pseudoobstruction is an uncommon clinical condition of varied etiologies. Confusion in its characterization and diagnosis often results in delay in diagnosis as well as inappropriate treatment involving repeated surgery. The various aspects and characteristics of intestinal pseudoobstruction are described by representative case reports of three patients treated in our department with a review of the literature. Heightened awareness, understanding of the physiological dynamics and recognition of the spectrum of its clinical presentation and diagnostic modalities should result in more efficacious treatment.
Non-Hodgkin’s lymphomas of the large bowel - clinical characteristics, prognostic factors and survival
Authors: Stanojevic G.Z. , Stojanovic M.P. , Stojanovic M.M. , Krivokapic Z. , Jovanovic M.M. , Katic V.V. , Jeremic M.M. , Brankovic B.R.
Published: November 2008

The aims of this study were to review the clinical presentation of non-Hodgkin?s lymphomas of the large bowel, to analyze the prognostic factors using univariate and multivariate methods, as well as the overall survival. We identified 24 cases at our clinic between 1991 and 2005, based on pathohistological analysis and standard diagnostic criteria established by Dawson et al. They accounted for 1,2% of all cases of the large bowel malignancies (24/2021) during this period. The following clinical information such as age, gender, symptoms, tumor localization, operation performed, histology grade, stage of disease, and adjuvant chemotherapy was obtained. Survival function was expressed by Kaplan-Meier curve and Log-rank test was performed for the difference in survival between two patient groups. Multivariate analysis was carried out using the Cox proportional hazard model. Overall mean survival time was 41,91months. According to the univariete analysis, the factors influencing overall survival rate was operation type (elective and emergent). Tumor stage and operation type were independent prognostic factors for survival, as determined by multivariate analysis. Our results showed that tumor stage and operation type should be considered as the most important prognostic factors in patients with primary non-Hodgkin?s lymphomas of the large bowel.
Digestive system damage caused by substance abuse
Authors: Dimitrijevic I. , Kalezic N. , Ristic J. , Bojovic O. , Dimitrijevic N.
Published: November 2008

Substance abuse and addiction represent a worldwide problem and cause a number of family, social and health problems. Digestive system damage caused by substance intake is an increasing problem amoung drug addicts. Many studies show that substances can cause cancer of all parts of the digestive system. Alcohol consumption was significantly associated with colon and rectal cancer. For rectal cancer, the risk was increased in association with drinking of alcoholic beverages, specially for beer consumption. Sinthetic drugs such as ecstasy may lead also to digestive and hepatic damage, as well as vascular complications of the stomach. Many studies show the existence of supstance associated enterocolitis as well as ishemic colitis. Diagnosis of ishemic colitis is based on the presence of rectal bleeding, abdominal pain, a history of substance use, supportive endoscopic and histopathologic findings, and the absence of other etiologic mechanisms of ischemic colitis. Great damage to the digestive system is also produced by smuggling narcotics packed into small pages that are afterwards been swallowed or implemented on other sorts of ways inside the smugglers natural body spaces as the rectum or vagina. In the paper authors reviewed literature conserning digestive system damage caused by substance abuse and drug smuggling.
The man-machine analogy in robotics and neurophysiology
Authors: Prochazka Arthur
Published: November 2008

Since the time of Descartes the machine-like control of movement in animals and the animal-like control of movement in automata has fascinated and inspired scientists, engineers and philosophers alike. In 1966, Drs. Rajko Tomovic and Robert McGhee proposed the concept of a "cybernetic actuator," a new type of control system which "possesses the property of producing continuous controlled motion from an input which may assume only four distinct states". The specific application at the time was an artificial limb prosthesis. Signals from sensors monitoring joint angle and ground contact were to be continuously compared to a set of threshold values corresponding to specific moments in the step cycle. The binary signals (above or below threshold) were listed in a look-up chart which associated sensory combinations with actuator states. It was proposed that this system would provide all of the known state transitions required of an above knee prosthesis. In this and later papers Tomovic was careful to point out the differences between such "artificial reflex control" systems and neural control systems in animals. Nonetheless in the last few years it has become commonplace to see the control of locomotion and other rhythmical behaviors described in terms of "sensory rules," that is in terms of finite state systems. With the advent of neural nets and fuzzy logic control robotic devices are taking on more and more of the features of biological control systems. In turn, neurophysiologists borrow more and more from the concepts and mechanisms of modern control theory. The influence of Tomovic's simple but powerful idea continues to spread.
Control of arm movement: reaching synergies for neuroprosthesis with life-like control
Authors: Popovic Mirjana , Popovic Dejan , Tomovic Rajko
Published: November 2008

This paper presents control methods for restoration of reaching and grasping that mimics the mapping in the space of output states found in healthy subjects. The hypothesis was that the externally driven movements are most likely to advance the recovery of functioning if they follow lifelike control mechanisms. For this, it is important to analyze movement considering the conditions such as: 1) variety of functional tasks (drinking, writing, using computer disk); 2) different locations of the object (with respect to the body); with respect to the active arm); 3) variable loading of the hand (light, heavy); and 4) available grasp strategy (palmar, lateral, pinch). The overall goals of our study were the following 1) identification of coordinated synergies in functional tasks, 2) investigation of differences and similarities between these synergies related to different grasp types, and 3) analysis of the impact of direction, distance and load to synergies. Three spatial reaching synergies were validated for the following coordinated rotations: shoulder adduction/abduction vs. elbow flexion/extension angular velocity (synergy SI), humeral rotation vs. elbow flexion/extension angular velocity (synergy S2), and shoulder vs. elbow flexion/extension angular velocity (synergy S3). These are timely synchronized with the phases of functional tasks; where four reaching phases were distinguished. Here, we present alternation of synergies' coupling during successive phases of a functional task. Preliminary results indicate that the two phases of a functional task termed "no-object" phases used one coupling, between synergies S2 and S3; while the two other phases termed "object" phases were coupled by synergies SI and S2. We established the generalization on the following two objectives: the discrimination of tasks' phases and matching the synergies with task phases. This result reduces the number of mappings necessary for the design of neuroprosthesis with life-like control.
Development of a closed-loop fes system using a 3-d magnetic position and orientation measurement system
Authors: Kurosawa Kenji , Watanabe Takashi , Futami Ryoko , Hoshimiya Nozomu , Handa Yasunobu
Published: November 2008

We have developed a closed-loop FES system using a magnetic 3-D position and orientation measurement system (FASTRAK, Polhemus Inc). The purpose of this development was to resolve some experimental difficulties involved in our previous goniometer-based experimental system. The new system enabled us to perform FES control experiments on the multi-joint musculoskeletal system of the upper limbs including forearm pronation/supination. In this paper, we evaluated the system by some single-joint tracking tasks in order to compare its control performance with that of the previous system. Four muscles (ECRL(B), ECU, FCR, and FCU) of neurologically intact subjects were stimulated to control the wrist joint's two degrees of freedom movement. Stimulation currents were determined by a multi-channel PID controller that was designed for a musculoskeletal system with redundancy (i.e. the number of muscles stimulated is more than that of the degree-of-freedom of the movement). The results showed that the system had sufficient control performance on tracking desired trajectories. Moreover, the system could compensate for unwanted external disturbances.
Adaptive filtering based on recurrent neural networks
Authors: Kihas Dejan , Djurovic Zeljko , Kovacevic Branko
Published: November 2008

Kalman filter is an optimal filtering solution in certain cases, however, it is more often than not, regarded as a non-robust filter. The slight mismatch in noise statistics or process model may lead to large performance deterioration and the loss of optimality. This research paper proposes an alternative method for robust adaptive filtering concerning lack of information of noise statistics. The method is based on the application of recurrent neural networks trained by a dynamic identity observer. The method is explained in details and tested in the case analysis of object tracking model. Performance evaluation is made for cases of the standard Kalman filter, a noise-adaptive Kalman filter, the adaptive filter with a recurrent neural network trained by a static identity observer, and the adaptive filter with recurrent neural network trained by a dynamic identity observer. The results for different noise statistics as well as noise statistics mismatches are compared and presented. It is shown that in cases with a lack of knowledge of the noise statistics it is beneficial to use the filtering method proposed in this research work.
Electronic circuits modeling using artificial neural networks
Authors: Andrejevic Miona , Litovski Vanco
Published: November 2008

In this paper artificial neural networks (ANN) are applied to modeling of electronic circuits. ANNs are used for application of the black-box modeling concept in the time domain. Modeling process is described, so the topology of the ANN, the testing signal used for excitation, together with the complexity of ANN are considered. The procedure is first exemplified in modeling of resistive circuits. MOS transistor, as a four-terminal device, is modeled. Then nonlinear negative resistive characteristic is modeled in order to be used as a piece-wise linear resistor in Chua's circuit. Examples of modeling nonlinear dynamic circuits are given encompassing a variety of modeling problems. A nonlinear circuit containing quartz oscillator is considered for modeling. Verification of the concept is performed by verifying the ability of the model to generalize i.e. to create acceptable responses to excitations not used during training. Implementation of these models within a behavioral simulator is exemplified. Every model is implemented in realistic surrounding in order to show its interaction, and of course, its usage and purpose.
Some applications of neural networks in microwave modeling
Authors: Milovanovic Bratislav , Markovic Vera , Marinkovic Zlatica , Stankovic Zoran
Published: November 2008

This paper presents some applications of neural networks in the microwave modeling. The applications are related to modeling of either passive or active structures and devices. Modeling is performed using not only simple multilayer perception network (MLP) but also advanced knowledge based neural network (KBNN) structures.
Explicit state and output feedback boundary controllers for partial differential equations
Authors: Smyshlyaev Andrey , Krstic Miroslav
Published: November 2008

In this paper the explicit (closed form) solutions to several application-motivated parabolic problems are presented. The boundary stabilization problem is converted to a problem of solving a specific linear hyperbolic partial differential equation (PDE). This PDE is then solved for several particular cases. Closed loop solutions to the original parabolic problem are also found explicitly. Output feedback problem under boundary measurement is explicitly solved with both anti-collocated and collocated sensor/actuator locations. It is shown how closed form frequency domain compensators based on the closed form observers and controllers can be designed.
Digital compass as heading sensor for hexapod robot
Authors: Andjelkovic Sasa , Velickovic Ivan , Rasic Milan , Djordjevic Goran
Published: November 2008

A growing research in biomimetic legged robot design challenges today's theory path planning and motion control. For many reasons a biomimetic robot requires a heading sensor onboard for better path following and steering. We propose a use of a digital compass as low-cost sensor. However, cheap versions of that sensor are extremely sensitive to inclination that occurs due to locomotion, resulting in incorrect measurements. This paper presents a modeling procedure of a digital compass performance with respect to altered roll and pitch angles. With information from an additional accelerometer as tilt sensor that reads roll and pitch angles of the robot the model improves the compass readings making it insensitive to altered tilt. The fusion of the modeling and a compass-accelerometer setup is experimentally verified.
Experimental study on low velocity friction compensation and tracking control
Authors: Popovic Milos , Liu Guangjun , Goldenberg Andrew
Published: November 2008

Stick-slip phenomenon is often associated with the control of low velocity motion because of the positional dependency of friction and negative damping friction that decreases as the motion speed increases. In this paper, smooth low velocity tracking control of a commercial robot joint is demonstrated experimentally using a combination of high gain PID control, fast sampling rate and high position sensor resolution. The experimental results also reveal that the main source of instability is not negative damping friction but position dependant friction that has been widely neglected. The short sampling period and a high resolution encoder have allowed us to compensate for the position dependant friction with a PID controller with sufficiently high gains.
Preliminary results of the ion trajectory tracking in the acceleration region of the VINCY Cyclotron
Authors: Ilic Andjelija , Ristic-Djurovic Jasna , Cirkovic Sasa
Published: November 2008

In an accelerating region of a cyclotron an ion makes a large number of turns; thus its tracking requires fast as well as highly accurate computation. Computer code, based on the adaptive time step fourth order Runge Kutta method, has been developed. Accuracy requirement is set simultaneously on the position and momentum calculation. Magnetic fields used as input, have been evaluated in terms of the radial fluctuations of the orbital frequency, i.e. their isochronism. Ion trajectory tracking has been performed for the four test beams: H-, H2 +, 4He+, and 40Ar6+.
Design of Fuzzy Logic Controller for autonomous garaging of mobile robot
Authors: Mitrovic Srdjan
Published: November 2008

The paper presents autonomous garaging method for mobile robot Hemisson K-Team. Original fuzzy magnetic approach was combined with human-like driving skills. Computer simulation results are given to show the validity of proposed fuzzy logic controller.
Nonlinear correlation receiver performance in UWB radio system
Authors: Milosevic Nenad , Dimitrijevic Bojan , Nikolic Zorica
Published: November 2008

The rejection of QPSK interference in a THPPM UWB system using complex adaptive filter and a nonlinear correlation receiver (NCR) with a soft-limiter will be considered in this paper. This system brings a significant performance improvement compared to the system which uses complex adaptive filter and a linear receiver, particularly in the case of high interference power, where its absence leads to the reception loss.
Antenna optimization using Particle Swarm Optimization algorithm
Authors: Golubovic Ruzica , Olcan Dragan
Published: November 2008

We present the results for two different antenna optimization problems that are found using the Particle Swarm Optimization (PSO) algorithm. The first problem is finding the maximal forward gain of a Yagi antenna. The second problem is finding the optimal feeding of a broadside antenna array. The optimization problems have 6 and 20 optimization variables, respectively. The preferred values of the parameters of the PSO algorithm are found for presented problems. The results show that the preferred parameters of PSO are somewhat different for optimization problems with different number of dimensions of the optimization space. The results that are found using the PSO algorithm are compared with the results that are found using other optimization algorithms, in order to estimate the efficiency of the PSO.
Neural network for noise modeling of SiGe HBT's
Authors: Stosic Aleksandar , Markovic Vera , Marinkovic Zlatica
Published: November 2008

The advantages of SiGe HBTs make them very promising for modern RF communication systems and therefore their noise performance becomes an important issue as well. This paper presents the noise modeling of SiGe HBTs for broad operating ranges. Two neural network structures are presented and discussed from the aspect of modeling accuracy: a basic one and an extended one obtained by adding the S-parameters to the input.
ACE spectrum of LDPC codes
Authors: Vukobratovic Dejan , Djurendic Aleksandar , Senk Vojin
Published: November 2008

Construction of short-length LDPC codes with good, both waterfall and error-floor, behavior is still an attractive research problem. Recently proposed construction algorithms in this field are based on remarkably simple ideas, but yet, their effectiveness can still be questioned. In this paper we investigate a novel measure of goodness of a given LDPC code namely its ACE spectrum, based on a previously introduced ACE metrics associated with each cycle in LDPC code graph.
Implementation of neural network in CBIR systems with relevance feedback
Authors: Kojic Nenad , Cabarkapa Slobodan , Zajic Goran , Reljin Branimir
Published: November 2008

A content-based image retrieval system where an active learning strategy is used to gain relevance feedback (RF) is described. In this way retrieving process may be highly accelerated without significant degradation of accuracy Searching procedure was performed through the two basic steps: an objective one, based on the Euclidean distances and a subjective one based on the user's relevance feedback. Images recognized from user as the best matched to a query are labeled and used for updating the query feature vector through a RBF (radial basis function) neural network. In this process user change feature vector which became more refined and appropriate for future search. In practice, several iterative steps are sufficient, as confirmed by intensive simulations.
Mn2+‐Doped CdSe Quantum Dots: New Inorganic Materials for Spin‐Electronics and Spin‐Photonics
Authors: Beaulac Rémi , Archer Paul I. , Ochsenbein Stefan T. , Gamelin Daniel R.
Published: November 2008

Recent advances in the chemistry of colloidal semiconductor nanocrystal doping have led to new materials showing fascinating physical properties of potential technological importance. This article provides an overview of efforts to dope one of the most widely studied colloidal semiconductor nanocrystal systems, CdSe quantum dots, with one of the most widely studied transition‐metal dopant ions, Mn2+, and describes the major new physical properties that have emerged following successful synthesis of this material. These properties include spin‐polarizable excitonic photoluminescence, magnetic circular dichroism, exciton storage, and excitonic magnetic polaron formation. A brief survey of parallel advances in the characterization of analogous self‐assembled Mn2+‐doped quantum dots grown by molecular beam epitaxy is also presented, and the physical properties of the colloidal quantum dots are shown to compare favorably with those of the self‐assembled quantum dots. The rich variety of physical properties displayed by colloidal Mn2+‐doped CdSe quantum dots highlights the attractiveness of this material for future fundamental and applied research.
Enhancement of Electrogenerated Chemiluminescence and Radical Stability by Peripheral Multidonors on Alkynylpyrene Derivatives
Authors: Oh Jeong‐Wook , Lee Yeon Ok , Kim Tae Hyun , Ko Kyoung Chul , Lee Jin Yong , Kim Hasuck , Kim Jong Seung
Published: November 2008

Ein Hoch auf den Elektronenspender: Die Effizienz der Elektrochemilumineszenz (ECL) und die Beständigkeit des radikalischen Zustands stiegen für den schlechten ECL‐Luminophor Pyren mit der Zahl peripherer Donoreinheiten merklich (siehe Bild). Diese ECL‐Verstärkung, die zur Entwicklung neuer Lichtemittermaterialien führen könnte, wurde mithilfe von photophysikalischen und elektrochemischen Studien sowie durch Rechnungen untersucht.

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Conversion of carbon dioxide to cyclic carbonates using diimine Ru(II) complexes as catalysts
Authors: Ulusoy Mahmut , Çetinkaya Engin , Çetinkaya Bekir
Published: November 2008

Cationic diimine Ru(II) complexes were synthesized and tested as catalysts for the formation of cyclic organic carbonates from CO2 and liquid epoxides (propylene oxide, epichlorohydrine, 1,2‐epoxybutane and styrene oxide) which served as both reactant and solvent. The reaction rates not only depended on the type of ligand, but also on reaction conditions such as temperature, pressure, base, the epoxide substrates and the use of an additional solvent. Reaction rates in terms of turnover frequencies up to 4050 molproduct molcat.−1 h−1 at 99% selectivity were achieved by optimizing the diimine ligand as well as the reaction temperature and CO2 pressure. Consistent with CV measurements, the electron donating group on the p‐position of the aryl ring accelerated the reaction rate. Copyright © 2008 John Wiley & Sons, Ltd.
Highly compatible wood thermoplastic composites from lignocellulosic material modified in ionic liquids: Preparation and thermal properties
Authors: Xie Haibo , Jarvi Paula , Karesoja Mikko , King Alistair , Kilpelainen Ilkka , Argyropoulos Dimitris S.
Published: November 2008

A study of converting chemically modified wood into thermoplastic materials was undertaken to develop a new technology platform for the effective utilization of wood‐based lignocellulosic materials. Highly substituted benzoylated spruce thermomechanical pulp (TMP) and lauroylated spruce TMP were used as components for thermoplastic composites of poly(styrene) and poly(propylene). Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic mechanical thermal analysis (DMTA) were used to characterize the interfacial morphology and thermal properties of the resultant composite filaments. The coupling of the interfacial morphology effort and that of torque analysis applied during processing indicated that the thorough modification of wood fibers by benzoylation and/or lauroylation reactions can improve the compatibility between the wood‐based lignocellulosic materials and poly(styrene) and poly(propylene). Thermal analysis showed that, with the addition of wood derivatives into poly(styrene) and poly(propylene) matrices, a slight decrease in their Tgs was observed. Furthermore, all of the prepared composites showed improved thermal stability, as revealed by TGA. The resultant thermoplastic wood composites exhibited good melting properties and were readily extruded into filaments or sheets. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Reaction kinetics and thermal properties of cyanate ester‐cured epoxy resin with phenolphthalein poly(ether ketone)
Authors: Li Junyan , Chen Ping , Ma Zemin , Ma Keming , Wang Baichen
Published: November 2008

This article describe the influence of phenolphthalein poly (ether ketone) (PEK‐C) on the cure behaviors and thermal properties of the diglycidyl ether of bisphenol A (DGEBA) epoxy resin with cyanate ester as curing agent. The curing kinetics and reaction pathways were monitored using dynamic differential scanning calorimeter and Fourier transform infrared spectroscopy. The dependence of activation energy on the conversion degree for all the studied systems was calculated in the light of Ozawa‐Flynn‐Wall method. Furthermore, the thermomechanical properties and the thermal stability of the cured resins were also evaluated by dynamic mechanical analysis and thermogravimetric analysis, respectively. Conclusions can be drawn as follows: the main reaction pathways did not vary with the inclusion of PEK‐C, but the reaction rate of the blend was found to be higher than that of the neat epoxy. The glass transition temperature of the blend was not changed by the addition of PEK‐C, while the initial decomposition temperature slightly decreased with increase in PEK‐C content. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and characterization of high molecular weight side chain liquid crystalline/photoactive polymers
Authors: Murali M. , Sudhakar P. , Kumar B. Satish , Samui A. B.
Published: November 2008

Various liquid crystalline and photoactive azobenzene monomers were synthesized and attached to copoly(methyl methacrylate‐glycidyl methacrylate) [copoly (MMA‐GMA)] to get high molecular weight side chain liquid crystalline (LC)/photoactive copolymers. Further, spacers are generated in situ and reactive groups are obtained after the modification. All monomers and polymers were thoroughly characterized by FTIR, 1H and 13C NMR, UV‐VIS spectrophotometry, gel permeation chromatography, thermogravimetric analysis, differential scanning calorimetry, and polarized optical microscopy. All side chain LC polymers showed higher thermal stability than that of copoly(MMA‐GMA). Three LC and one azo monomer exhibited characteristic nematic mesophase where as one LC monomer has shown nematic and sanded smectic‐A texture. The rate of trans‐cis isomerization of polymer was lower than that of the monomer and both monomers and polymers showed slow back isomerization. Present approach offers convenient way to synthesize high/desired molecular weight photoactive LC polymers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Ammonia/acetylene plasma deposition: An alternative approach to the dyeing of poly(ethylene terephthalate) fabrics at low temperatures
Authors: Hossain M. M. , Müssig J. , Herrmann A. S. , Hegemann D.
Published: November 2008

It has long been recognized that dyes other than disperse dyes would play a much larger industrial role if they could be applied to poly(ethylene terephthalate) (PET) fabrics at low temperatures. This research is related to a new process for the dyeing of hydrophobic PET with hydrophilic acid dyestuffs. The process is based on low‐pressure plasma polymerization using an ammonia/acetylene gaseous mixture, which provides a nanoporous plasma coating containing accessible amine groups. Surface functionalization and crosslinking have been analyzed with X‐ray photoelectron spectroscopy. The color strength (absorption coefficient/scattering coefficient) of dyed PET is evidently improved by the attachment of dye molecules to the plasma polymer coating. The dyeability strongly depends on the plasma exposure time, gaseous mixture, and energy input. The permanency of the bond between the dye molecules and the plasma film can be characterized as the fastness property of dyed PET. The stability of the plasma coating has been examined with an abrasion and pilling tester. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Plasticity structural analysis of polymer nanocomposites filled with carbon nanotubes
Authors: Zaikov G. E. , Kozlov G. V. , Aphashagova Z. K. , Mikitaev A. K.
Published: November 2008

A structural analysis of an increasing plasticity effect for polymer nanocomposites filled with carbon nanotubes was carried out. It was shown that this effect was due to densely packed interfacial layer formation on an atomic scale on the smooth nanotube surfaces, which resulted in changes in the polymer molecular matrix and structural characteristics. A prediction of the nanocomposite properties as a function of nanotube contents was obtained. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Higher taxa are effective surrogates for species in the selection of conservation reserves in estuaries
Authors: Shokri Mohammad Reza , Gladstone William
Published: November 2008

The lack of information about marine biodiversity is problematic for the selection of conservation reserves that aim to protect representative samples of biodiversity. A number of surrogate measures for biodiversity have been suggested as a potential solution to this problem.

The present study tested the effectiveness of using higher taxa of macroinvertebrates as a surrogate for species‐level identification to depict spatial variation in species richness and assemblage variation and to select conservation reserves in one estuary in south‐east Australia.

Spatial patterns of richness and assemblage variation for species were significantly correlated with patterns defined from genera, families, orders, classes, and phyla with a decline in the magnitude of correlation coefficients from finer to coarser resolutions. A network of reserves selected to include representatives of all phyla, classes, orders, families and genera coincidentally included 54%, 61.7%, 75%, 92.6%, 98.8% species in 8.3%, 13.9%, 17.7%, 44.4% and 58.3% of grid cells, respectively. However, only reserves selected for genera, families and orders performed significantly better than random selection.

Percentage of species represented by orders, families and genera in a realistic level of available grid cells for conservation (i.e. 13.9%) were very close ranging between 70 and 73.5%. A factor diminishing the performance of order as surrogate for species richness was related to the difficulty of identifying many macroinvertebrates to the order level. Therefore, it is concluded that genus‐ and family‐level identification is an effective surrogate for species‐level identification for conservation planning in estuaries.

Copyright © 2008 John Wiley & Sons, Ltd.
A geophysical investigation of subsurface structures and Quaternary geology at San Marcos Pueblo, New Mexico
Authors: Hinz Emily A. , Ferguson John F. , Pellerin Louise , Ramenofsky Ann F.
Published: November 2008

San Marcos Pueblo site (LA 98), located in the Galisteo Basin south of Santa Fe, New Mexico, encompasses the remains of 43 identified room blocks, a Spanish mission and 20 middens. As part of ongoing field investigations at San Marcos, students and faculty from the Summer of Applied Geophysical Experience (SAGE) field programme are using multiple geophysical techniques to non‐invasively investigate the site. Modelling of the underlying Quaternary stream terrace geology and the detection of subsurface Pueblo‐era features were accomplished through the integrated interpretation of data from seismic refraction and reflection, electromagnetic, magnetic and ground‐penetrating radar methods. Although to date only a targeted spatially small extent of the site has been explored using these methods, the SAGE field programme has been able detect a variety of anthropogenic structures and debris. The SAGE field programme validated the presence of excavations in the natural stream terrace sequence over areas believed to contain kivas, mapped the geometry of walls over a closed room block, and detected an area of magnetized debris associated with smelting operations. Collectively, the data from the SAGE field programme demonstrate the value of using multiple, complementary, geophysical methods for archaeological prospection. Copyright © 2008 John Wiley & Sons, Ltd.
Determination of grave locations in Dedemezari Necropolis (Western Turkey) using magnetic field derivatives
Authors: Büyüksaraç A. , Arisoy M. Ö. , Bektaş Ö. , Koçak Ö. , Çay T.
Published: November 2008

The location of the study area for this research of a Middle Bronze Age Necropolis is situated in the west of Turkey near Afyonkarahisar. Magnetic surveying was carried out in two adjacent areas (Areas 4 and 5). Four trenches have been excavated so far and graves were located in positions interpreted from a magnetic survey carried out in 2005. Initial excavations have shown that cist, pithos and simple graves were placed randomly and it is suggested that Dedemezari Necropolis is similar to the well known necropoleis of Gordion and Sariket. This paper compares the results of some phase‐based filters which show improved performance as edge detectors in different ways. The filters are demonstrated on synthetic magnetic data and magnetic field data from Dedemezari Necropolis. Magnetic field derivatives, both vertical and horizontal, are common and useful tools for interpretation of the magnetic anomalies. Interpretation of magnetic field derivatives, separately or together, provide images of shallow bodies from magnetic data. The horizontal derivatives of the total magnetic field were computed in the space domain by means of finite‐difference relationships, and the vertical derivative was computed in the frequency domain by using fast Fourier transform filtering. Derivatives of the magnetic anomalies have been used for detection of causative bodies. The analytic signal (AS), the enhanced horizontal derivative (EHD), tilt derivative (TD), theta map, hyperbolic tilt angle (HTA) and total horizontal derivative (THDR) methods were applied not only to synthetic anomalies but also to the measured magnetic anomalies of Areas 4 and 5. However, AS and EHD produced the best results as the other methods created edge effects. Copyright © 2008 John Wiley & Sons, Ltd.
Ground‐penetrating radar survey for subfloor mapping and analysis of structural damage in the Sagrado Corazón de Jesús Church, Spain
Authors: Ramírez‐Blanco Manuel , García‐García Francisco , Rodríguez‐Abad Isabel , Martínez‐Sala Rosa , Benlloch Javier
Published: November 2008

This work presents the results of a ground‐penetrating radar (GPR) survey of the Sagrado Corazón de Jesús Church (seventeenth century AD). The church belongs to the artistic heritage of the Society of Jesus and is located in the old part of the city of Valencia (Spain). The GPR survey had two main objectives: discovering subfloor features and determining the causes of structural failure, particularly cracks and fractures detected in the building. For the fieldwork, 200 MHz and 400 MHz centre frequency antennae were used and a total of 53 profiles were acquired. The analysis of the reflection profiles and amplitude time‐slices showed the presence of a sloping substrate below part of the church. The slope of this substrate and the fact that the church had been built near the old Arab wall of the city (eleventh century AD) suggests that the church was built on top of a moat (ditch). The variable thickness and differential compaction of the subfloor layers probably caused differential settlings in the building and therefore be the origin of some of the structural failures observed in the church. There was also a reflection hyperbola in the profiles of the east transept of the church that was hypothesized to be the reflection from the ceiling of an undocumented crypt due to its shape, size and location. That reflection feature was tested using a boroscope and found to be a brick barrel‐vault crypt. Copyright © 2008 John Wiley & Sons, Ltd.
Understanding help seeking within the context of searching digital libraries
Authors: Xie Iris , Cool Colleen
Published: November 2008

To date, there has been little empirical research investigating the specific types of help‐seeking situations that arise when people interact with information in new searching environments such as digital libraries. This article reports the results of a project focusing on the identification of different types of help‐seeking situations, along with types of factors that precipitate them among searchers of two different digital libraries. Participants (N = 120) representing the general public in Milwaukee and New York City were selected for this study. Based on the analysis of multiple sources of data, the authors identify 15 types of help‐seeking situations among this sample of novice digital library users. These situations are related to the searching activities involved in getting started, identifying relevant digital collections, browsing for information, constructing search statements, refining searches, monitoring searches, and evaluating results. Multiple factors that determine the occurrences of each type of help‐seeking situation also are identified. The article concludes with a model that represents user, system, task, and interaction outcome as codeterminates in the formation of help‐seeking situations, and presents the theoretical and practical implications of the study results.
Controlling the Structure of Manganese(II) Phosphates by the Choice and Ratio of Organophosphate and Auxiliary Ligands
Authors: Murugavel Ramaswamy , Kuppuswamy Subramaniam , Gogoi Nayanmoni , Steiner Alexander , Bacsa John , Boomishankar Ramamoorthy , Suresh K. G.
Published: November 2008

Tetranuclear manganese(II) phosphates [Mn(dipp)(bpy)]4⋅4 H2O (1) and [Mn4(dmpp)2(dmppH)4(bpy)4(H2O)2]⋅H2O (2) have been prepared from Mn(OAc)2⋅4 H2O and 2,6‐diisopropylphenyl phosphate (dippH2) or 2,6‐dimethylphenyl phosphate (dmppH2) in the presence of 2,2′‐bipyridine (bpy). In contrast, the reaction between [Mn(bpy)2(OAc)(ClO4)]⋅H2O and dippH2 affords [Mn(bpy)2(dippH)]2⋅2 ClO4⋅2 CH3OH (3). The reactions of Mn(OAc)2⋅4 H2O, dippH2, and pyridine (py) or 3,5‐dimethylpyrazole (dmpz) in CH3CN under reflux afford hexanuclear complexes [Mn6(dipp)6(py)8]⋅2CH3CN (4) and [Mn6(dipp)6(dmpz)6(AcOH)2]⋅2 H2O (5), respectively. Although compounds 1 and 2 are tetrameric, the former is a closed cubane‐like structure resembling the D4R secondary building unit of zeolites, whereas the latter exists in a staircase structure with fused Mn2O4P2 rings. The core structure of 3 contains a Mn2O4P2 eight‐membered ring that resembles the S4R building block of zeolites. Single‐crystal X‐ray diffraction studies reveal that compounds 4 and 5 have a similar core structure and differ from each other by the neutral ligands coordinated to manganese ions. All six phosphate ligands exist in a doubly deprotonated [(RO)PO32−] form and exhibit two types of binding modes [5.222] and [3.111]. An interesting feature of compounds 1–5 is that although they are oligonuclear complexes, there is an absence of oxido bridges. The magnetic properties of compounds 1–5 have been investigated in the temperature range 5–298 K, and it was found that all the compounds obey the Curie law.
Probing the kinematics of early‐type galaxy halos using planetary nebulae
Authors: Coccato L. , Gerhard O. , Arnaboldi M. , Das P. , Douglas N.G. , Kuijken K. , Merrifield M.R. , Napolitano N.R. , Noordermeer E. , Romanowsky A.J. , Capaccioli M. , Cortesi A. , De Lorenzi F. , Freeman K.C.
Published: November 2008

We present first results of a study of the halo kinematics for a sample of early type galaxies using planetary nebulae (PNe) as kinematical tracers. PNe allow to extend up to several effective radii (Re) the information from absorption line kinematics (confined to within 1 or 2Re), providing valuable information and constraints for merger simulations and galaxy formation models.We find that the specific angular momentum per unit mass has amore complex radial dependence when the halo region is taken into account and that the halo velocity dispersion is related to the total galaxy luminosity, isophotal shape, and number of PNe per unit of luminosity. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The orbital structure of the massive elliptical galaxy NGC 5846
Authors: Das P. , Gerhard O. , Coccato L. , Churazov E. , Forman W. , Finoguenov A. , Böhringer H. , Arnaboldi M. , Capaccioli M. , Cortesi A. , Lorenzi F. de , Douglas N. G. , Freeman K. C. , Kuijken K. , Merrifield M. R. , Napolitano N. R. , Noordermeer E. , Romanowsky A. J.
Published: November 2008

We use density and temperature profiles obtained from XMM‐Newton observations to derive a potential of NGC 5846 out to 11Re, thus probing the mass distribution deep into the halo. The inferred circular velocity is significantly higher than the extrapolation of dynamical models implying a halo, more massive than previously thought. Using an I ‐band surfacebrightness profile and a projected velocity dispersion profile consisting of long‐slit kinematic measurements and planetary nebulae (PNe) velocity dispersions, we solve the Jeans equations, assuming a non‐rotating spherical system. The solutions suggest a highly radially anisotropic galaxy outside 0.7Re with β ∼ 0.75. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Radial velocities, dynamics of stars and nebulosities with GAIA and VLT‐GIRAFFE
Authors: Martayan C. , Frémat Y. , Blomme R. , Jonckheere A. , Delle‐Luche C. , Sartoretti P. , Katz D. , Viala Y. , Floquet M. , Hubert A.‐M. , Neiner C.
Published: November 2008

This document is divided in two parts. The first part deals with the radial velocities (RV) distributions for B‐type stars and nebulosities observed with the VLT‐GIRAFFE in the Large and Small Magellanic Clouds towards the open clusters NGC2004 and NGC330. Thanks to the resolution of GIRAFFE spectra, we found that the RV distribution for the nebulosities in the LMC is bi‐modal. This bi‐modality can be interpreted, in term of dynamics, by the expansion of the LMC4 super‐bubble. The second part deals with the GAIA space mission and the determination of the radial velocities by using Radial Velocity Spectrometer (RVS) spectra. The methods to determine the radial velocities are presented as well as preliminary results on simulated RVS spectra. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Are ring galaxies the ancestors of giant low surface brightness galaxies?
Authors: Mapelli M. , Moore B.
Published: November 2008

Giant low surface brightness galaxies (GLSBs), such as Malin 1, have unusually large and flat discs. Their formation is a puzzle for cosmological simulations in the cold dark matter scenario. We suggest that GLSBs might be the final product of the dynamical evolution of collisional ring galaxies. In fact, our simulations show that, approximately 0.5–1.5 Gyr after the collision which lead to the formation of a ring galaxy, the ring keeps expanding and fades, while the disc becomes very large (∼100 kpc) and flat. At this stage, our simulated galaxies match many properties of GLSBs (surface brightness profile, morphology, H I spectrum and rotation curve). (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Group 12 Dihalides: Structural Predilections from Gases to Solids
Authors: Donald Kelling J. , Hargittai Magdolna , Hoffmann Roald
Published: November 2008

Connections between the structures of Group 12 dihalides in their vapor and crystal phases are sought and discussed. The molecular structures of all monomers and dimers (MX2: M=Zn, Cd, Hg and X=F, Cl, Br, I) were calculated at the density functional B3PW91 and MP2 computational levels. All the monomers are linear, with the mercury dihalide molecules having shorter bonds than their cadmium analogues; the ZnX2 and CdX2 structures are similar. The shorter HgX distances are traced back to relativistic effects. For the dimers, many possible geometrical arrangements were considered. The zinc and cadmium dihalide dimers have the usual D2h‐symmetry geometry, whereas the mercury dihalide dimers are loosely‐bound units with C2h symmetry. The origins of this C2h structure are discussed from different points of view, including frontier orbital interactions. The crystals of Group 12 dihalides span a wide range of structure types, from three‐dimensional extended solids to molecular crystals. There is an obvious connection between the structures and characteristics of monomers, their dimers, and the crystals they form. The similarities as well as startling differences from the Group 2 dihalides are analyzed.