bluuebunny/crossref_metadata_2025_split huggingface dataset:
Real‐time navigating crowds: scalable simulation and rendering
Authors: Pettré Julien , Ciechomski Pablo de Heras , Maïm Jonathan , Yersin Barbara , Laumond Jean‐Paul , Thalmann Daniel 
Published: June 2006

AbstractThis paper introduces a framework for real‐time simulation and rendering of crowds navigating in a virtual environment. The solution first consists in a specific environment preprocessing technique giving rise to navigation graphs, which are then used by the navigation and simulation tasks. Second, navigation planning interactively provides various solutions to the user queries, allowing to spread a crowd by individualizing trajectories. A scalable simulation model enables the management of large crowds, while saving computation time for rendering tasks. Pedestrian graphical models are divided into three rendering fidelities ranging from billboards to dynamic meshes, allowing close‐up views of detailed digital actors with a large variety of locomotion animations. Examples illustrate our method in several environments with crowds of up to 35 000 pedestrians with real‐time performance. Copyright © 2006 John Wiley & Sons, Ltd.
Structure and Bonding in First‐Row Transition‐Metal Dicarbides: Are They Related to the Stability of Met‐cars?
Authors: Rayón Víctor M. , Redondo Pilar , Barrientos Carmen , Largo Antonio 
Published: June 2006

AbstractFirst‐row transition‐metal dicarbides MC2(M=Sc–Zn) have been investigated by using quantum‐mechanical techniques. The competition between cyclic and linear isomers in these systems has been studied and the bonding scheme for these compounds is discussed through topological analysis of electron density. All of the systems have been found to prefer aC2v‐symmetric arrangement, although for ZnC2the energy difference between this and the linear isomer is rather small. In most cases theC2v‐symmetric structure corresponds to a T‐shaped structure, with the exceptions of TiC2, CoC2, and NiC2which have been shown to be true rings. A detailed analysis of the variation of the energy of the system with geometry has been carried out. An analysis of the bonding, taking into account the main interactions between the valence orbitals of both fragments, the M atom and the C2molecule, has allowed the main features of these compounds to be interpreted. A clear correlation between the dissociation energies of the first‐row transition‐metal dicarbides and the bonding energies of the corresponding met‐cars was observed.
Iterative Deoxypropionate Synthesis Based on a Copper‐Mediated Directed Allylic Substitution: Formal Total Synthesis of Borrelidin (C3–C11 Fragment)
Authors: Herber Christian , Breit Bernhard 
Published: June 2006

AbstractA new iterative strategy for the flexible preparation of any oligodeoxypropionate stereoisomer is presented which relies on an o‐DPPB‐directed copper mediated allylic substitution employing enantiomerically pure Grignard reagents; the reaction is working with perfect control over all aspects of the reaction selectivity. This key CC bond‐forming step features reversed polarity compared with established enolate alkylation methodology. It thus avoids existing problems of enolate alkylation strategies such as enolate reactivity as well as costs and problems associated with the chiral auxiliary. Practicability of this new method is demonstrated through application in natural product syntheses. Thus, an efficient synthesis of the northern part of the angiogenesis inhibitor borrelidin (28), the deoxypropionate building block 27, could be devised, representing a formal total synthesis.
Pentafluorosulfanyl (SF5) Containing Energetic Salts
Authors: Gao Haixiang , Ye Chengfeng , Winter Rolf W. , Gard Gary L. , Sitzmann Michael E. , Shreeve Jean’ne M. 
Published: June 2006

AbstractNew quaternary salts of pentafluorosulfanyl‐substituted (SF5)N‐methylimidazole (1), 4‐amino‐1,2,4‐triazole (3) or pyridine (5) were prepared and characterized. Most of the salts exhibit good thermal stabilities and low melting points placing them in the ionic liquid class. Their densities range between 1.4 and 1.8 g/cm3. The standard enthalpies of formation for the new salts were calculated by the use of computationally feasible DFT(B3LYP) and MP2 methods in conjunction with an empirical approach based on densities of salts. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Electrochemical Behavior of MCF‐7 Cells on Carbon Nanotube Modified Electrode and Application in Evaluating the Effect of 5‐Fluorouracil
Authors: Chen Kun , Chen Jinhua , Guo Manli , Li Zhenfeng , Yao Shouzhuo 
Published: June 2006

AbstractThe electrochemical behavior of human breast cancer cells (MCF‐7) suspension on multiwalled carbon nanotube (MWCNT) modified graphite electrode was studied by using cyclic voltammetry (CV) and potentiometric stripping analysis (PSA). Compared with bare graphite electrode, the MWCNTs‐modified electrode showed electrocatalytic property to the oxidation of electroactive species in the cell suspension. One oxidative peak at about +0.74 V was observed in the cyclic voltammogram. PSA was proved to be more sensitive than CV for investigation of the electrochemical behavior of cells. And it was found that ultrasonication treatment of the cell suspension can significantly enhance the PSA signal. Factors influencing the PSA signal of cells, including deposition time, deposition potential and stripping current, were investigated in detail and the optimum conditions were obtained. The baseline corrected PSA signal was found to be related to the viability of cells and the technique was used for monitoring the growth of MCF‐7 cells. The effect of anticancer drug 5‐fluorouracil (5‐FU) on the growth of MCF‐7 cells was also investigated by PSA.
Speciation of Antimony by Adsorptive Stripping Voltammetry Using Pyrogallol Red
Authors: González M. Jesús Gómez , Domínguez Renedo Olga , Arcos Martínez M. Julia 
Published: June 2006

AbstractThis paper proposes a procedure for the speciation of antimony by Differential Pulse Adsorptive Stripping Voltammetry (DPAdSV) using pyrogallol red (PGR) as a complexing agent. It employs a Partial Least Squares regression (PLS) in the resolution of strongly overlapping voltammetric signals obtained from mixtures of Sb(III) and Sb(V) in the presence of pyrogallol red. The absolute value of the relative error was less than 3.5% when concentrations of several mixtures were calculated, the minimum concentrations being 9.98×10−9 mol dm−3and 4.87×10−8 mol dm−3for Sb(III) and Sb(V), respectively. Any undue effects caused by the presence of foreign ions in the solution were also analyzed. The procedure was successfully applied to the speciation of antimony in pharmaceutical preparations.
Anti‐radical power gives insight into early lipid oxidation events during frying
Authors: van Loon Wil AM , Linssen Jozef PH , Legger Aagje , Voragen Alphons GJ 
Published: June 2006

AbstractThe aim of this research was to use anti‐radical power (ARP) to study early lipid oxidation events during frying. The 2,2‐diphenyl‐1‐picrylhydrazyl radical (DPPH•) test was used to determine the ARP. As oil does not dissolve completely in methanol, which is generally used for the DPPH• test, butanol was used instead. Changing the solvent did not influence the value of the ARP. The decrease of the ARP highly correlated with the increase of the peroxide value for soybean oil heated at 110 °C (R2 = 0.99). Sensory analysis showed that rancidity of soybean oil and frying oil, heated at 180 °C, was perceived before the ARP decreased. Once the oil was perceived as rancid, the intensity of rancidity did not change significantly upon further heating. The ARP of soybean oil was found to decrease faster at 110 °C than at 180 °C, suggesting different mechanisms of radical formation. The total polar compounds of frying oil in which French fries were fried did not differ significantly from frying oil that was heated alone. However, frying of French fries caused more hydrolysis of the oil, while the ARP decreased faster when the oil was heated alone. Copyright © 2006 Society of Chemical Industry
The economics of nonprofit organizations
Authors: Hughes Patricia 
Published: June 2006

AbstractThis article presents an economic view of Nonprofit institutions and insight into what the discipline can offer Nonprofit practitioners. I review the theories and assumptions behind economic models, then give an overview of the major areas of economic research in the Nonprofit sector. I then discuss various factors to consider when judging the quality of economic research. The discussion then turns to a brief overview of the major statistical tool used by economists: regression analysis. The point is not to teach practitioners to become expert econometricians but to provide a framework to judge the quality of economic research. The article concludes with suggestions for economic research that may be undertaken at the firm level.
Historical research for the nonprofit sector
Authors: Hammack David C. 
Published: June 2006

AbstractBecause there are many possible uses of history and conceptions of what constitutes historical inquiry, there can be no single description of “historical research for the nonprofit sector.” Nonprofit researchers, like all nonprofit leaders, cannot avoid having views of historical development; neither can they avoid the necessity of drawing conclusions from incomplete and indeterminate evidence, just as all historians must do. Students of the Nonprofit sector might want to pay particular attention to questions raised by legal and economic history (others have made much of the relevance of social and intellectual history). Most generally, historical materials and perspectives are especially relevant to the education of nonprofit leaders.
The catalyst process: What academics provide to practitioners
Authors: Milofsky Carl 
Published: June 2006

AbstractIn this article, I explore what academics may offer community groups and practitioners by suggesting that scholars serve as catalysts that make community projects possible. One goal is to propose the catalyst model as a way of refocusing the action research paradigm. Action research is an established paradigm for scholars who wish to combine their research agenda with a desire to partner with community leaders on change projects. Discussions of action research tend to focus on the value of the approach for academics and methodological strategies that allow them to produce research their university colleagues consider legitimate. In the catalyst approach, we explore what university people provide in pragmatic terms that allows community movements and projects to move ahead. I deemphasize expert knowledge and focus instead on institutional resources. Scholars provide a gateway to a rich resource environment. The organization of professional work also allows scholars to give continuity to projects and to provide a framework that allows projects that otherwise might stall to move toward completion. The catalyst model eliminates the notion that scholars and practitioners belong to fundamentally different intellectual cultures and thereby removes one of the perceived barriers to effective action research. The model also indicates some organizational strategies for university people to use should they wish to set up long‐term university‐community partnerships..
How to create a mentoring program
Authors: Brescia William 
Published: June 2006

AbstractMentoring the Next Generation of Nonpro.t Leaders: A Practical Guide for Managers, by Ken Williams. Washington, D.C.: AED Center for Leadership Development, Academy for Educational Development, 2005. 36 pp., $15.00 paper or available online (http://newvoices.aed.org/MentoringNext Generation.pdf).
Inhibitory activity on HIV‐1 reverse transcriptase and integrase of a carmalol derivative from a brown Alga, Ishige okamurae
Authors: Ahn M.‐J. , Yoon K.‐D. , Kim C. Y. , Kim J. H. , Shin C.‐G. , Kim J. 
Published: June 2006

AbstractThe bioassay‐directed isolation of a marine brown alga, Ishige okamurae, afforded a carmalol derivative, diphlorethohydroxycarmalol. This compound exhibited inhibitory effects on HIV‐1 reverse transcriptase and integrase with IC50 values of 9.1 µm and 25.2 µm, respectively. However, diphlorethohydroxycarmalol did not show an inhibitory activity against HIV‐1 protease. Moreover, diphlorethohydroxycarmalol nonaacetate obtained by acetylation and fucosterol failed to show any inhibitory activity against these viral enzymes. Copyright © 2006 John Wiley & Sons, Ltd.
Anticonvulsant effect of Persea americana Mill (Lauraceae) (Avocado) leaf aqueous extract in mice
Authors: Ojewole John A. O. , Amabeoku George J. 
Published: June 2006

AbstractVarious morphological parts of Persea americana Mill (Lauraceae) (avocado) are widely used in African traditional medicines for the treatment, management and/or control of a variety of human ailments, including childhood convulsions and epilepsy. This study examined the anticonvulsant effect of the plant's leaf aqueous extract (PAE, 50–800 mg/kg i.p.) against pentylenetetrazole (PTZ)‐, picrotoxin (PCT)‐ and bicuculline (BCL)‐induced seizures in mice. Phenobarbitone and diazepam were used as reference anticonvulsant drugs for comparison. Like the reference anticonvulsant agents used, Persea americana leaf aqueous extract (PAE, 100–800 mg/kg i.p.) significantly (p < 0.05–0.001) delayed the onset of, and antagonized, pentylenetetrazole (PTZ)‐induced seizures. The plant's leaf extract (PAE, 100–800 mg/kg i.p.) also profoundly antagonized picrotoxin (PCT)‐induced seizures, but only weakly antagonized bicuculline (BCL)‐induced seizures. Although the data obtained in the present study do not provide conclusive evidence, it would appear that ‘avocado’ leaf aqueous extract (PAE) produces its anticonvulsant effect by enhancing GABAergic neurotransmission and/or action in the brain. The findings of this study indicate that Persea americana leaf aqueous extract possesses an anticonvulsant property, and thus lends pharmacological credence to the suggested ethnomedical uses of the plant in the management of childhood convulsions and epilepsy. Copyright © 2006 John Wiley & Sons, Ltd.
Quantitative Structure–Activity Relationship of the 4,5α‐Dihydrotestosterone Steroid Family
Authors: Alvarez‐Ginarte Yoanna María , Crespo‐Otero Rachel , Marrero‐Ponce Yovani , Montero Luis Alberto , Ruiz‐García José Alberto , Padrón‐García Alexander , Zaragoza Francisco Torrens 
Published: June 2006

AbstractPredictive Quantitative Structure–Activity Relationship (QSAR) models of Anabolic/Androgenic (A/A) activities for the 4,5α‐dihydrotestosterone steroid family were obtained by means of multilinear regression using quantum and physicochemical Molecular Descriptors (MDs) as well as a genetic algorithm for the selection of the best subset of MDs. MDs included in our QSAR models allow the structural interpretation of the biological process, evidencing the main role of the shape of molecules, hydrophobicity, and electronic properties. Attempts were made to include lipophilicity (octanol–water partition coefficient) as well as electronic (lowest unoccupied molecular orbital properties and dipole moment) values of the whole molecules in the multivariate relations. It was found from the study that the calculated net charges by semiempirical methods of different atoms in the steroid nucleus [atoms 4 (ring A), 8 (bridgeheads of rings B and C), 11 (ring C) 13 (fusion points of rings C and D), and 16 (ring D)] contribute significantly to binding affinity. The found MDs can also be efficiently used in similarity studies based on cluster analysis. Our model for the A/A ratio (expressed by the weights of the levator ani muscle/ventral prostate in mice) predicts that 2α, 3α‐difluoro‐methylene‐17α‐methyl‐5α‐androstan‐17β‐ol (13) is the most potent anabolic steroid. By contrast, the 17α‐methyl‐2β, 17β‐dihydroxy‐5α‐androstane (16) is flagged as the least potent anabolic steroid. The approach described in this report is an alternative for the discovery and optimization of leading anabolic compounds among steroids and analogues. It also gives an important role to electron exchange terms of molecular interactions to this kind of steroid activity.
Ultra‐fast tandem mass spectrometry scanning combined with monolithic column liquid chromatography increases throughput in proteomic analysis
Authors: Batycka Mariola , Inglis Neil F. , Cook Ken , Adam Alex , Fraser‐Pitt Douglas , Smith David G. E. , Main Laura , Lubben Anneke , Kessler Benedikt M. 
Published: June 2006

AbstractLiquid chromatography combined with electrospray ionization mass spectrometry (LC/ESI‐MS) has been used successfully for the characterization of biomolecules in proteomics in the last few years. This methodology relied largely on the use of reversed‐phase chromatography, in particular C18‐based resins, which are suitable for separation of peptides. Here we show that polymeric [polystyrene divinylbenzene] monolithic columns can be used to separate peptide mixtures faster and at a higher resolution. For 500 fmol bovine serum albumin, up to 68% sequence coverage and Mascot Mowse scores of >2000 were obtained using a 9 min gradient on a monolithic column coupled to an ion trap mass spectrometer with ultra‐fast MS/MS scan rates. In order to achieve similar results using C18 columns, it was necessary to extend gradient times to 30 min. In addition, we demonstrate the utility of this approach for the analysis of whole Escherichia coli cell lysates by one‐dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (1D‐SDS‐PAGE) in combination with LC/MS/MS using 4 min gradients on monolithic columns. Our results indicate higher throughput capabilities of monolithic columns (3‐fold gain in time or more) for conventional proteomics applications, such as protein identification and high sequence coverage usually required for detection of post‐translational modifications (PTMs). Further optimization of sensitivity and quality of sequence information is discussed, in particular when combined with mass spectrometers that have very fast MS‐MS/MS switching and scanning capabilities. Copyright © 2006 John Wiley & Sons, Ltd.
New surfaces for desorption electrospray ionization mass spectrometry: porous silicon and ultra‐thin layer chromatography plates
Authors: Kauppila Tiina J. , Talaty Nari , Salo Piia K. , Kotiaho Tapio , Kostiainen Risto , Cooks R. Graham 
Published: June 2006

AbstractThe performance of nanoporous silicon (pSi) and ultra‐thin layer chromatography (UTLC) plates as surfaces for desorption electrospray ionization (DESI) was compared with that of polymethyl methacrylate (PMMA) and polytetrafluoroethylene (PTFE), both popular surfaces in previous DESI studies. The limits of detection (LODs) and other analytical characteristics for six different test compounds were determined using all four surfaces. The LODs for the compounds were in the fmol–pmol (pg–ng) range. The LODs with the pSi surface were further improved for each of the compounds when heat was applied to the surface during sample application which gave LODs as low as or lower than those achieved with PMMA and PTFE. The UTLC plates were successfully used as a rapid means of chromatographic separation prior to DESI‐MS analysis. Another advantage achieved using the newer pSi and UTLC surfaces was increased speed of analysis, associated with drying of solution‐phase samples. This took place immediately at the UTLC surface and it could be achieved rapidly by gently heating the pSi surface. The presence of salts in the sample did not cause suppression of the analyte signal with any of the surfaces. Copyright © 2006 John Wiley & Sons, Ltd.
State modelling of self‐excited induction generator for wind power applications
Authors: Wamkeue R. , Songia L. , Lakehal M. , Viarouge P. 
Published: June 2006

AbstractThe increase in wind power production with self‐excited induction generators (SEIGs) has led to new kinds of protection and stability problems. Suitable state models of a wind plant with SEIGs must accurately simulate balanced and unbalanced transient phenomena for adequate calibration and control of protection devices. However, the SEIG models currently available are unable to simulate the neutral current following unbalanced faults for forecasting the SEIG insulation and protection needed against some network stresses. In addition, the saturation model commonly used is not flexible when deriving a state model. This article presents an effective electromechanical state model for transient analysis of a saturated SEIG for wind power applications. A neutral connection through impedance is included for exact modelling of a Park wye‐connected SEIG. Simple‐shunt and short‐shunt (series) configurations are explored. A comparative analysis of the effects of these two types of configuration on the steady state and transient performances of an SEIG is presented. Numerical and experimental data obtained with a 380V, 5·5kVA, 11·9A, 50Hz induction generator are presented to attest to the effectiveness of the proposed SEIG modelling framework. Among the results obtained, simulations show that the simple‐shunt configuration produces poor voltage regulation, possible voltage collapse and inherent protection against short‐circuit faults, while the short‐shunt connection provides better voltage variation but needs to be well protected against short‐circuit faults. Copyright © 2006 John Wiley & Sons, Ltd.
The relationship of vegetation to environmental factors in Wangsuk stream and Gwarim reservoir in Korea: II. Soil environments
Authors: Kwon Gi Jin , Lee Bo Ah , Nam Jong Min , Kim Jae Geun 
Published: June 2006

AbstractThis paper presents a quantitative account of vegetation–soil environmental factor relationships in the Wangsuk stream (WS) and the Gwarim reservoir (GR) in Korea. Vegetation and the following soil variables were investigated in May, August and October 2004: pH, conductivity, water content, organic matter, total nitrogen content, NH4–N content, PO4–P content, total Ca, Mg, K, and Na content, extractable Ca, Mg, K and Na content, soil texture, distance from the channel, and elevation above water level. Species richness, diversity and ratio of hydrophyte occupation in WS were different from those in GR. Species richness was higher in WS, whereas the ratio of hydrophyte occupation was higher in GR. There were large temporal and spatial variations in plant distribution in the riparian and aquatic zones of WS but only slight variations in those of GR. These differences might have arisen from differences in flooding regime, distance from the stream channel related to elevation above water level, and soil properties such as soil texture and available nutrients. The median values of organic matter, total nitrogen, NH4–N, PO4–P and extractable Ca, Mg, K and Na contents in the soil were higher in GR than in WS. Sandy loam and loamy sand were common soil types in WS and clay loam and sandy clay loam in GR. Ten vegetation groups in WS and six in GR were identified using TWINSPAN. DCCA indicated that the distance from the stream channel was most strongly related to plant distribution and this reflected the spatial distribution of plant species in WS. In both WS and GR, NH4–N content in soil and soil texture were important factors for the distribution of species in May, August and October. Spatial and temporal heterogeneity of soil variables were related to species distribution.