bluuebunny/crossref_metadata_2025_split huggingface dataset:
The QSAR Modeling of Cytotoxicity on Anthraquinones
Authors: Takkis Kalev , Sild Sulev , Maran Uko 
Published: June 2009

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

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

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

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

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

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

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

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

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

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

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

AbstractObjectivesTo determine the prevalence of clinical symptoms associated with Cesarean scar defects, and to determine the association between the size of these defects, clinical complaints, uterine position, and a history of multiple Cesarean sections.MethodsIn this cross‐sectional study, Cesarean scar defects in women with a history of transverse lower‐segment Cesarean section were measured by transvaginal ultrasound while being assessed for other gynecological conditions. The relationships between the size of the Cesarean scar defect and the clinical symptoms, uterine position and number of previous Cesarean sections were evaluated. Patients with other uterine pathologies, including endometrial hyperplasia, polyps, malignancy and submucosal myomas, were excluded from the study.ResultsDuring a 3‐year period, 4250 women were assessed by transvaginal sonography, of whom 293 (6.9%) were diagnosed with Cesarean scar defects. Eighty‐six patients were excluded due to other uterine pathologies. Altogether, 207 patients with Cesarean scar defects were included in this study. Women who had undergone multiple Cesarean sections tended to have larger scar defects (in width and depth) than did those who had undergone a single Cesarean section. Women with retroflexed uteri also tended to have wider defects than those with anteflexed uteri. Defect width was significantly greater in women with postmenstrual spotting, dysmenorrhea and chronic pelvic pain.ConclusionsMultiple Cesarean sections and retroflexed uteri are risk factors for larger Cesarean scar defects. The size of the Cesarean scar defect is associated with clinical symptoms such as postmenstrual spotting, dysmenorrhea and chronic pelvic pain. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Three‐dimensional ultrasound detection of abnormally located intrauterine contraceptive devices which are a source of pelvic pain and abnormal bleeding
Authors: Benacerraf B. R. , Shipp T. D. , Bromley B. 
Published: June 2009

AbstractObjectiveTo determine whether intrauterine contraceptive devices (IUDs) that are located abnormally within the myometrium or cervix cause a higher incidence of pelvic pain and abnormal bleeding compared with normally positioned devices.MethodsOver a period of 9 months, all patients with an IUD presenting at our unit for two‐dimensional pelvic ultrasound underwent a three‐dimensional (3D) volume reconstruction of the coronal view, to visualize the entire IUD within the cavity. The IUD was deemed malpositioned if any part extended past the cavity, into the myometrium or cervix. The indications for ultrasound were recorded at presentation for the exam. The presenting symptoms of patients with an abnormally located IUD were compared with those with normally positioned ones.ResultsAmong 167 consecutive patients with an IUD evaluated using the 3D reconstructed coronal view, 28 (16.8%) had an IUD with side arms abnormally located within the myometrium. The abnormal positioning of the IUD arms was only detected using the 3D coronal view. A higher proportion of patients with an abnormally located IUD presented with bleeding (35.7%) or pain (39.3%) compared with those with normally positioned IUDs (15.1% with bleeding and 19.4% with pain) (P = 0.02 and 0.03, respectively). Seventy‐five percent of patients with an abnormally located IUD presented with bleeding or pain compared with 34.5% of those whose IUD was normally placed (P = 0.0001). Twenty of 21 patients with an abnormally located IUD presenting with pelvic pain or bleeding reported improvement in their symptoms after IUD removal.ConclusionA 3D coronal view of the uterus is useful in the visualization of IUDs. The coronal view showing the entire device and its position within the uterus may help in identifying the cause of pelvic pain and bleeding in patients with an embedded IUD. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Myocardial tissue Doppler assessment of diastolic function in the growth‐restricted fetus
Authors: Naujorks A. A. , Zielinsky P. , Beltrame P. A. , Castagna R. C. , Petracco R. , Busato A. , Nicoloso A. L. H. , Piccoli A. , Manica J. L. 
Published: June 2009

AbstractObjectivesMyocardial tissue Doppler (MTD) is a technique for the measurement of myocardial velocities in systole and diastole. This study evaluates the use of MTD in the assessment of cardiac diastolic function in fetuses with intrauterine growth restriction (IUGR) with placental insufficiency and in appropriate‐for‐gestational age (AGA) fetuses with hypertensive mothers.MethodsThis study included 14 IUGR fetuses with placental insufficiency (Group 1), 13 AGA fetuses with hypertensive mothers (Group 2), and 29 AGA fetuses with healthy mothers (Group 3). Patients with other diseases were excluded. All fetuses had a gestational age of at least 25 weeks. MTD assessment was performed with the sample volume placed at the basal segment of the left ventricular side wall (LV), the interventricular septum (IVS) and the right ventricular free wall (RV). E′/A′ ratios were calculated for each location. Mitral and tricuspid flows were assessed by conventional spectral pulsed Doppler.ResultsSignificant differences were found between groups for E′/A′ at the IVS (P < 0.001) and LV (P = 0.009), with a higher mean (± SD) value in Group 1 (IVS: 0.92 ± 0.28; LV: 0.85 ± 0.19) than in Groups 2 (IVS: 0.62 ± 0.09; LV: 0.68 ± 0.14) and 3 (IVS: 0.71 ± 0.14; LV: 0.69 ± 0.15). In the RV, there was no statistically significant difference in the E′/A′ ratio (P = 0.2). No differences were observed for mitral and tricuspid flow velocities and ratios.ConclusionsUsing MTD, the ratios between early and late diastolic myocardial velocities are higher in IUGR fetuses than in AGA fetuses at the IVS and the LV, regardless of the presence of maternal hypertension. MTD may be more sensitive than atrioventricular spectral Doppler for the detection of ventricular diastolic dysfunction in IUGR fetuses. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
The L2E method
Authors: Scott David W. 
Published: June 2009

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

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

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

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

AbstractAn improved X‐ray structure determination of magnesium indenide Mg(C9H7)2 (1) at low temperature was carried out. Four donor‐acceptor complexes of Mg(C9H7)2 (1) with O‐ and N‐donor Lewis bases were synthesized and characterized by X‐ray structure analysis. With dioxane and tetramethylethylenediamine (TMEDA) two simple monomeric complexes, [Mg(C9H7)2(dioxane)2]·1.5dioxane (2a) and [Mg(C9H7)2(TMEDA)] (3), were formed. With the O‐donors tetrahydrofuran (THF) and dimethylsulfoxide (DMSO) two ionic magnesium compounds 4 and 5 could be synthesized which have a [MgL6]2+ cation [L = THF and DMSO] and two uncoordinated indenide anions.