Home About us Contact
|
Home About us Contact | ||
|
|
||
New Methodology (new + methodology)
Selected AbstractsSolid-Phase Reactive Chromatography (SPRC): A New Methodology for Wittig and Horner,Emmons Reactions on a Column under Microwave IrradiationEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 2 2010Saada C. Dakdouki Abstract A new methodology named solid-phase reactive chromatography (SPRC), which combines reaction, separation, and purification into a single unit for the preparation of small samples, is described. This method was illustrated in the synthesis of some natural bioactive compounds, namely, methoxylated analogues of resveratrol, alkylresorcinols, and 5-aryl-2,4-pentadienoates, over a column of alumina-KF under microwave irradiation by using the Wittig and Horner,Emmons reactions. This approach permitted the preparation of the target olefins with high purity and good to excellent yields in short reaction times. [source] Estimating Returns on Commercial Real Estate: A New Methodology Using Latent-Variable ModelsREAL ESTATE ECONOMICS, Issue 2 2000David C. Ling Despite their widespreao use as benchmarks of U.S. commercial real estate returns, indexes produced by the National Council of Real Estate Investment Fiduciaries (NCREIF) are subject to measurement problems that severely impair their ability to capture the true risk,return characteristics,especially volatility,of privately held commercial real estate. We utilize latent-variable statistical methods to estimate an alternative index of privately held (unsecuritized) commercial real estate returns. Latent-variable methods have been extensively applied in the behavioral sciences and, more recently, in finance and economics. Unlike factor analysis or other unconditional statistical approaches, latent variable models allow us to extract interpretable common information about unobserved private real estate returns using the information contained in various competing measures of returns that are measured with error. We find that our latent-variable real estate return series is approximately twice as volatile as the aggregate NCREIF total return index, but less than half as volatile as the NAREIT equity index. Overall, our results strongly support the use of latent-variable statistical models in the construction of return series for commercial real estate. [source] New Methodology for the Deoxygenative Difluoromethylenation of Aldehydes and Ketones; Unexpected Formation of Tetrafluorocyclopropanes.CHEMINFORM, Issue 27 2005Ireneusz Nowak Abstract For Abstract see ChemInform Abstract in Full Text. [source] Enantioselective H-Atom Transfer Reactions: A New Methodology for the Synthesis of ,2 -Amino Acids.CHEMINFORM, Issue 26 2004Mukund P. Sibi Abstract For Abstract see ChemInform Abstract in Full Text. [source] A New Methodology of Anellation of Five- and Seven-Membered Heterocycles to Quinoxalines.CHEMINFORM, Issue 18 2004A. M. Boguslavskiy Abstract For Abstract see ChemInform Abstract in Full Text. [source] A New Methodology for Synthesis of a Chiral Phosphinocarboxylic Acid Through Michael Cyclization,Aldol Tandem Reaction of Chiral ,,,,,,,-Unsaturated Bisphosphine Oxide and Application in Palladium-Catalyzed Asymmetric Allylic Alkylation.CHEMINFORM, Issue 3 2003Hediki Inoue No abstract is available for this article. [source] New Methodology for the Preparation of 3-Hydroxy-2-pyridinone (3,2-HOPO) Chelators , Reaction of Amines with a Novel Electrophilic 3,2-HOPO Precursor.CHEMINFORM, Issue 52 2002Timothy N. Lambert Abstract For Abstract see ChemInform Abstract in Full Text. [source] New methodologies in teaching e-structural mechanics using WWW,COMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 3 2008Carmelo Maiorana Abstract A recently initiated phase of experimentation and research in the online Distance Learning (DL) is here described. The project has been developed by the Department of Construction and Transportation Engineering of the Faculty of Engineering at the University of Padua along with the well-established e-learning experience of the SSIS Veneto (Institute for the Formation of Secondary School's Teachers) of Cà Foscari,University of Venice, in collaboration with the webmaster management of TCN-EnginSoft of Padua. The work deals with teaching methodologies supported by the net, computer communication and information technologies, finalized to give both widespread access to useful resources and to create a more flexible exchange due to net communication. The experimentation of using web-based technologies to support traditional teaching for working students is described; in fact, Internet-based innovations offer opportunities for a curriculum improvement to those categories of students who could be considered at a disadvantage, like worker students or students with ear or motion deafness. © 2008 Wiley Periodicals, Inc. Comput Appl Eng Educ 16: 189,210, 2008; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae20167 [source] Cover Picture: Electrophoresis 13'09ELECTROPHORESIS, Issue 13 2009Article first published online: 20 JUL 200 Issue 13 is a special issue on "CE and CEC of Amino Acids, Peptides and Proteins" assembling 19 papers on various topics including fast, high efficient and high sensitive "CE and CEC techniques for quality control and purity determination of native and (bio)synthetic amino acids, peptides and proteins, for monitoring of their synthesis, isolation, chemical derivatization and enzymatic digestion and also for investigation of their interactions with other molecules. New methodologies, such as electrodialysis for sample preparation, chiral ligand-exchange CE, immunoaffinity CE, affinity capillary isoelectric focusing, combination of transient isotachophoretic preconcentration with capillary zone electophoresis (CZE) analysis, two-dimensional CE-mass spectrometry (MS) separations and advances in high-sensitive CE-laser induced fluorescence (LIF) and CE-electrochemiluminescence detection schemes, are widely presented here. The applications of CE and CEC methods include chiral analysis of amino acids, determination of low abundant amino acids, peptides and proteins in complex matrices, such as human and animal body fluids and tissue biopsies, and profiling of cell lysates and recombinant proteins, e.g. birch pollen allergen and human interleukin 7. As can be seen from several contributions, preparation of new capillary coatings suppressing the adsorption of peptides and proteins to the fused silica capillary wall in their CZE analyses and/or increasing the selectivity of their open-tubular CEC separations remains a hot topic in the area of CE and CEC developments. In addition, it is shown that through the theoretical modelling of the CZE determined effective electrophoretic mobilities of proteins, the important parameters, such as charge, hydration and shape of their molecules, can be estimated." [source] Comparison of Commonly Used Assays for the Detection of MicroalbuminuriaJOURNAL OF CLINICAL HYPERTENSION, Issue 2004Douglas E. Busby MD There are a variety of methods for assessing urinary albumin excretion, extending from the very low-range microalbuminuria to higher ranges extending into macroalbuminuria or proteinuria. The recommendation for the initial screening of a new patient is to use a urine dipstick to assess for microalbuminuria. If positive, a spot urine for albumin:creatinine should be measured and reassessed annually. All patients with kidney disease, diabetes, or hypertension and metabolic syndrome should be screened for albuminuria. New methodologies using high-performance liquid chromatography are much more sensitive and specific when compared with older methods of detection and may prove very useful for earlier identification of high-risk patients. This is important since studies have shown that albuminuria levels below the microalbuminuria range, determined by conventional methodologies in uncomplicated essential hypertensive men, are associated with an adverse cardiovascular and metabolic risk profile. High performance liquid chromatography methodology, in contrast to older studies, detects all intact albumin and enables clinicians to assess disease severity and monitor therapeutic effectiveness with confidence in the accuracy of the microalbuminuria data reported to them. [source] Overview and new developments in softer X-ray (2Å < , < 5Å) protein crystallographyJOURNAL OF SYNCHROTRON RADIATION, Issue 1 2004John R. Helliwell New methodologies with synchrotron radiation and X-ray free electron lasers (XFELs) in structural biology are being developed. Recent trends in harnessing softer X-rays in protein crystallography for phase determination are described. These include reference to a data-collection test at 2.6 Å wavelength with a lysozyme crystal on SRS station 7.2 (Helliwell, 1983) and also use of softer X-rays (2,Å wavelength) to optimise f," at the xenon L1 absorption edge in the Single Isomorphous Replacement Optimised Anomalous Scattering ('SIROAS') structure determination of apocrustacyanin A1 with four, partially occupied, xenon atoms (Cianci et al., 2001; Chayen et al., 2000). The hand of the protein was determined using the f," enhanced sulphur anomalous signal from six disulphides in the protein dimer of 40,kDa. In a follow-up study the single wavelength xenon L1 -edge f," optimised data set alone was used for phase determination and phase improvement by solvent flattening etc. (CCP4 DM) (Olczak et al., 2003). Auto-tracing of the protein was feasible but required additional diffraction data at higher resolution. This latter could be avoided in future by using improved tilted detector settings during use of softer X-rays, i.e. towards back-scattering recording (Helliwell, 2002). The Olczak et al. study has already led to optimisation of the new SRS beamline MPW,MAD,10 (see www.nwsgc.ac.uk) firstly involving the thinning of the beryllium windows as much as possible and planning for a MAR Research tilted detector `desk top beamline' geometry. Thus the use of softer, i.e. 2 to 3,Å wavelength range, X-rays will allow optimisation of xenon and iodine L -edge f," and enhancing of sulphur f," signals for higher throughput protein crystallography. Softer X-rays utilisation in protein crystallography includes work done on SRS bending-magnet station 7.2 in the early 1980s by the author as station scientist (Helliwell, 1984). In the future development of XFELs these softer X-ray wavelengths could also be harnessed and relax the demands to some extent on the complexity and cost of an XFEL. Thus, by use of say 4,Å XFEL radiation and use of a back-scattering geometry area detector the single molecule molecular transform could be sampled to a spatial resolution of 2,Å, sufficient, in principle, for protein model refinement (Miao et al., 1999). Meanwhile, Miao et al. (2003) report the first experimental recording of the diffraction pattern from intact Escherichia coli bacteria using coherent X-rays, with a wavelength of 2,Å, at a resolution of 30,nm and a real-space image constructed. The new single-particle X-ray diffraction-imaging era has commenced. [source] New methodology for using incognito standardised patients for telephone consultation in primary careMEDICAL EDUCATION, Issue 1 2009Hay Derkx Context, Many countries now use call centres as an integral part of out-of-hours primary care. Although some research has been carried out on safety issues pertaining to telephone consultations, there has been no published research on how to train and use standardised patients calling for medical advice or on the accuracy of their role-play. Objectives, This study aimed to assess the feasibility and validity of using telephone incognito standardised patients (TISPs), the accuracy of their role-play and the rate of detection. Further objectives included exploring the experiences of TISPs and the difficulties encountered in self-recording calls. Methods, Twelve TISPs were trained in role-play by presenting their problem to a general practitioner and a nurse. They were also trained in self-recording calls. Calls were made to 17 different out-of-hours centres (OOHCs) from home. Of the four or five calls made per evening, one call was assessed for accuracy of role play. Retrospectively, the OOHCs were asked whether they had detected any calls made by a TISP. The TISPs filled in a questionnaire concerning their training, the self-recording technique and their personal experiences. Results, The TISPs made 375 calls over 84 evenings. The accuracy of role-play was close to 100%. A TISP was called back the same evening for additional information in 11 cases. Self-recording caused extra tension for some TISPs. All fictitious calls remained undetected. Conclusions, Using the method described, TISPs can be valuable both for training and assessment of performance in telephone consultation carried out by doctors, trainees and other personnel involved in medical services. [source] Omnidirectional multibeam sonar monitoring: applications in fisheries scienceFISH AND FISHERIES, Issue 3 2006Patrice Brehmer Abstract Data exploitation, acquired by medium-frequency omnidirectional multibeam sonar, enables original studies in fisheries research but is seldom used despite the fact that such equipment is found on most fishing vessels and a number of research vessels. This is the only system for real-time monitoring of fish schools within a horizontal omnidirectional plane about a vessel or a buoy. Between 1996 and 2001, we used two standard omnidirectional sonars and developed new methodologies for exploiting their specific acoustic data according to two main sampling schemes: ,prospecting', including fishing and searching operations, and ,drifting', as with an instrumental buoy system or aboard a stationary vessel. We present a complete method for continuous data acquisition from aboard a research vessel or commercial boat, with automated data extraction by picture analysis and a data processing method. Two cases of data analysis are considered: the first on a school-by-school basis, the ,single school' mode; the second taking into account all fish schools detected within the sonar sampling volume, the ,cluster' mode. Elementary sonar information is divided into five categories that comprise 24 survey and sonar parameters and 55 school, cluster and fisher behaviour descriptors. We review the applications of these categories and discuss perspectives for their use in fisheries science. If the sonar system enables the evaluation of the effects of vessel avoidance on fish school biomass assessment, no accurate abundance estimate can be provided by a simple sonar echo-integration process. Omnidirectional sonar data can be used to analyse collectively the fish schools' swimming speed, kinematics in terms of diffusion and migration, aggregative dynamics as school splitting and merging indexes, spatial characteristics of clusters such as school density, 2D structure and fisher behaviour. The prospect of integrating such data into a fish school database, including multifrequency echo-sounder and lateral multibeam (3D) sonar data combined with a species recognition method, will enable a complete view of fish school behaviour and consequently the adoption of accurate fisheries management methods. [source] The european union risk assessment on zinc and zinc compounds: The process and the factsINTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT, Issue 4 2005Charles W.M. Bodar Abstract A risk assessment on zinc and zinc compounds was carried out within the framework of Council Regulation 793/93/EEC on Existing Chemicals. This risk assessment basically followed the European Union (EU) technical guidance documents (TGDs). These TGDs are built on the current knowledge on quantitative risk assessments, mainly for organic chemicals. This article describes the tailor-made approach for the zinc risk assessment. This work lasted almost a decade and involved the contributions of all EU member states and industry, who discussed the risk assessment during technical meetings. The risk assessment is initially based on scientific findings but is interrelated with pragmatic considerations. It follows a comprehensive approach, covering both environmental and human health. In the environmental part, new methodologies were developed to deal with the natural background of zinc, essentiality, speciation, and the use of species sensitivity distributions. The major results and the process of drawing conclusions of the risk assessment are outlined: potential environmental risks of zinc and zinc compounds may occur at local and regional scales in surfacewater, sediment, and soil. No potential health risks were identified for consumers and man indirectly exposed via the environment. For workers, potential health risks were identified only for zinc oxide and zinc chloride. [source] Defining the nursing contribution to patient outcome: lessons from a review of the literature examining nursing outcomes, skill mix and changing rolesJOURNAL OF CLINICAL NURSING, Issue 1 2001Karen Spilsbury BA , ,A review of the evidence to define the nursing contribution to patient outcome is presented. The review relies on work related to nursing sensitive outcomes, skill mix and changing roles. , ,Methodological difficulties associated with these studies are highlighted. , ,Areas requiring further research are discussed. , ,It is suggested that experimental evidence is not always appropriate, when attempting to describe nursing activity. The authors advocate that new methodologies, in particular practitioner-centred research, are needed to unpack the nature of nursing. [source] What have We Learnt from the Convergence Debate?JOURNAL OF ECONOMIC SURVEYS, Issue 3 2003Nazrul Islam This paper surveys the convergence literature. It begins by laying out different definitions of convergence and by showing the link between the convergence issue and the growth theory debate. The paper then follows the convergence research conducted along four different approaches, namely the cross-section, panel, time-series, and distribution approaches. The paper shows the association of these methodological approaches with various definitions of convergence and highlights the connections among the convergence results. It shows that, despite some impressions to the contrary, there is considerable agreement among the results. Although the convergence research might not have solved the growth debate entirely, it has helped both the neoclassical and the new growth theories to adapt and evolve. The research on convergence has established new stylized facts regarding cross-country growth regularities. It has brought to fore the existence of large technological and institutional differences across countries and has given rise to new methodologies for quantifying and analyzing these differences. This is providing a new information base for analysis of technological and institutional diffusion and for further development of growth theory in general. [source] What is the biological relevance of the specific bond properties revealed by single-molecule studies?,JOURNAL OF MOLECULAR RECOGNITION, Issue 6 2007Philippe Robert Abstract During the last decade, many authors took advantage of new methodologies based on atomic force microscopy (AFM), biomembrane force probes (BFPs), laminar flow chambers or optical traps to study at the single-molecule level the formation and dissociation of bonds between receptors and ligands attached to surfaces. Experiments provided a wealth of data revealing the complexity of bond response to mechanical forces and the dependence of bond rupture on bond history. These results supported the existence of multiple binding states and/or reaction pathways. Also, single bond studies allowed us to monitor attachments mediated by a few bonds. The aim of this review is to discuss the impact of this new information on our understanding of biological molecules and phenomena. The following points are discussed: (i) which parameters do we need to know in order to predict the behaviour of an encounter between receptors and ligands, (ii) which information is actually yielded by single-molecule studies and (iii) is it possible to relate this information to molecular structure? Copyright © 2007 John Wiley & Sons, Ltd. [source] Facile syntheses of 4-vinyl-1,2,3-triazole monomers by click azide/acetylene couplingJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 9 2008Kenichi Takizawa Abstract Synthetic strategies for the preparation of a new family of vinyl monomers, 4-vinyl-1,2,3-triazoles, have been developed. These monomers are noteworthy as they combine the stability and aromaticity of styrenics with the polarity of vinylpyridines and the structural versatility of acrylate/methacrylate derivatives. To enable the wide adoption of these unique monomers, new methodologies for their synthesis have been elaborated which rely on Cu-catalyzed azide/acetylene cycloaddition reactions,"click chemistry",as the key step, with the vinyl substituent being formed by either elimination or Wittig-type reactions. In addition, one-pot "click" reactions have been developed from alkyl halides, which allow for monomer synthesis without isolation of the intermediate organic azides. The high yield and facile nature of these procedures has allowed a library of new monomers including the parent compound, 1- H -4-vinyl-1,2,3-triazole, to be prepared on large scales. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2897,2912, 2008 [source] The structure and function of auditory chordotonal organs in insectsMICROSCOPY RESEARCH AND TECHNIQUE, Issue 6 2004Jayne E. Yack Abstract Insects are capable of detecting a broad range of acoustic signals transmitted through air, water, or solids. Auditory sensory organs are morphologically diverse with respect to their body location, accessory structures, and number of sensilla, but remarkably uniform in that most are innervated by chordotonal organs. Chordotonal organs are structurally complex Type I mechanoreceptors that are distributed throughout the insect body and function to detect a wide range of mechanical stimuli, from gross motor movements to air-borne sounds. At present, little is known about how chordotonal organs in general function to convert mechanical stimuli to nerve impulses, and our limited understanding of this process represents one of the major challenges to the study of insect auditory systems today. This report reviews the literature on chordotonal organs innervating insect ears, with the broad intention of uncovering some common structural specializations of peripheral auditory systems, and identifying new avenues for research. A general overview of chordotonal organ ultrastructure is presented, followed by a summary of the current theories on mechanical coupling and transduction in monodynal, mononematic, Type 1 scolopidia, which characteristically innervate insect ears. Auditory organs of different insect taxa are reviewed, focusing primarily on tympanal organs, and with some consideration to Johnston's and subgenual organs. It is widely accepted that insect hearing organs evolved from pre-existing proprioceptive chordotonal organs. In addition to certain non-neural adaptations for hearing, such as tracheal expansion and cuticular thinning, the chordotonal organs themselves may have intrinsic specializations for sound reception and transduction, and these are discussed. In the future, an integrated approach, using traditional anatomical and physiological techniques in combination with new methodologies in immunohistochemistry, genetics, and biophysics, will assist in refining hypotheses on how chordotonal organs function, and, ultimately, lead to new insights into the peripheral mechanisms underlying hearing in insects. Microsc. Res. Tech. 63:315,337, 2004. © 2004 Wiley-Liss, Inc. [source] Synthesis and NMR characterization of 6-Phenyl-6-deoxy-2,3-di- O -methylcellulose,POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 6 2002Dr Navzer (Nozar) D. Sachinvala Abstract Cellulose (1) was converted for the first time to 6-phenyl-6-deoxy-2,3-di- O -methylcellulose (6) in 33% overall yield. Intermediates in the five-step conversion of 1 to6 were: 6- O -tritylcellulose (2), 6- O -trityl-2,3-di- O -methylcellulose (3), 2,3-di- O -methylcellulose (4); and 6-bromo-6-deoxy-2,3-di- O -methylcellulose (5). Elemental and quantitative carbon-13 analyses were concurrently used to verify and confirm the degrees of substitution in each new polymer. Gel permeation chromotography (GPC) data were generated to monitor the changes in molecular weight (DPw) as the synthesis progressed, and the compound average decrease in cellulose DPw was , 27%. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to characterize the decomposition of all polymers. The degradation temperatures (,°C) and percent char at 500,°C of cellulose derivatives 2 to 6 were 308.6 and 6.3%, 227.6,°C and 9.7%, 273.9,°C and 30.2%, 200.4,°C and 25.6%, and 207.2,°C and 27.0%, respectively. The glass transition temperature (Tg) of6- O -tritylcellulose by dynamic mechanical analysis (DMA) occurred at 126.7,°C and the modulus (E,, Pa) dropped 8.9 fold in the transition from ,150,°C to,+,180,°C (6.6,×,109 to 7.4,×,108 Pa). Modulus at 20,°C was 3.26,×,109 Pa. Complete proton and carbon-13 chemical shift assignments of the repeating unit of the title polymer were made by a combination of the HMQC and COSY NMR methods. Ultimate non-destructive proof of carbon,carbon bond formation at C6 of the anhydroglucose moiety was established by generating correlations between resonances of CH26 (anhydroglucose) and C1,, H2,, and H6, of the attached aryl ring using the heteronuclear multiple-bond correlation (HMBC) method. In this study, we achieved three major objectives: (a) new methodologies for the chemical modification of cellulose were developed; (b) new cellulose derivatives were designed, prepared and characterized; (c) unequivocal structural proof for carbon,carbon bond formation with cellulose was derived non-destructively by use of one- and two-dimensional NMR methods. Copyright © 2002 John Wiley & Sons, Ltd. [source] CASE REPORTS: Penile Constriction Devices: Case Report, Review of the Literature, and Recommendations for ExtricationTHE JOURNAL OF SEXUAL MEDICINE, Issue 7 2008Jonathan Silberstein ABSTRACT Introduction., Penile constriction devices often present significant challenges to urologic surgeons. Failure to remove such devices can lead to significant ischemia and loss of tissue. Patients often present after several days of ischemia and swelling have developed. Aim., This article reviews previously published data on penile constriction devices and strategies for their removal. Additionally, we present new methodologies for extrication. Methods., A comprehensive review of the English language literature was performed using MEDLINE. "Penile incarceration" and "penile strangulation" were used as search terms, and a manual bibliographic review of cross-referenced items was performed. Publications prior to 1970 were excluded from our search. Main Outcome Measures., Review of published literature on penile constriction devices and their removal. Results., Penile incarceration is frequently described in the literature as an isolated case report or small series describing the approach of a single physician or group of physicians for dealing with these problems. Penile incarceration has been reported in a wide spectrum of age groups, with the incarcerating object most frequently placed for erotic or autoerotic purposes. While the most commonly reported devices causing incarceration are metal rings, higher-grade penile injuries are more frequently sustained by nonmetallic objects. Patients who present with incarceration after 72 hours are more likely to sustain higher-grade injuries than those who seek more timely treatment. Strategies for extrication depend on the type of device used, the length of time of incarceration, the patient's ability to remain calm, and the tools available to the presenting physicians. Conclusion., Penile incarceration is a urologic emergency with potentially severe clinical consequences. With rapid intervention and removal of the foreign body, most patients do extremely well and need no further intervention. Removal of such devices can be challenging and often requires resourcefulness and a multidisciplinary approach. Silberstein J, Grabowski J, Lakin C, and Goldstein I. Penile constriction devices: Case report, review of the literature, and recommendations for extrication. J Sex Med 2008;5:1747,1757. [source] Improving assessments of marine protected areasAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 2 2010Joachim Claudet Abstract 1.The use of experimental design and statistical analysis to evaluate the effects of marine protected areas (MPAs) is increasingly popular throughout the world. 2.However, in looking at historical approaches to MPA evaluations, flaws were identified in the execution of theoretically correct designs, as well as disconnects between the stated objectives of MPAs and those of assessment studies. 3.MPA assessments can be improved by: (1) considering the enforcement/compliance level; (2) linking explicitly the choice of indicator(s) to the MPA objectives; (3) accounting for habitat structure; (4) taking into account the age and size of the MPA; and (5) quantifying the fishing pressure outside the MPA (including possible displacement effects). 4.Neglecting social factors, using inappropriate indicators, and/or ignoring relevant covariates, carries the risk of having MPAs dismissed as an effective management tool. Societal expectations are strong that MPAs will confer benefits, and thus assessment studies need to be progressively improved using new methodologies and the best available scientific evidence. Copyright © 2009 John Wiley & Sons, Ltd. [source] Structure of anti-FLAG M2 Fab domain and its use in the stabilization of engineered membrane proteinsACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 9 2006Tarmo P. Roosild The inherent difficulties of stabilizing detergent-solubilized integral membrane proteins for biophysical or structural analysis demand the development of new methodologies to improve success rates. One proven strategy is the use of antibody fragments to increase the `soluble' portion of any membrane protein, but this approach is limited by the difficulties and expense associated with producing monoclonal antibodies to an appropriate exposed epitope on the target protein. Here, the stabilization of a detergent-solubilized K+ channel protein, KvPae, by engineering a FLAG-binding epitope into a known loop region of the protein and creating a complex with Fab fragments from commercially available anti-FLAG M2 monoclonal antibodies is reported. Although well diffracting crystals of the complex have not yet been obtained, during the course of crystallization trials the structure of the anti-FLAG M2 Fab domain was solved to 1.86,Å resolution. This structure, which should aid future structure-determination efforts using this approach by facilitating molecular-replacement phasing, reveals that the binding pocket appears to be specific only for the first four amino acids of the traditional FLAG epitope, namely DYKD. Thus, the use of antibody fragments for improving the stability of target proteins can be rapidly applied to the study of membrane-protein structure by placing the short DKYD motif within a predicted peripheral loop of that protein and utilizing commercially available anti-FLAG M2 antibody fragments. [source] In vitro neuromuscular activity of snake venomsCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 9 2002Wayne C Hodgson Summary 1.,Snake venoms consist of a multitude of pharmacologically active components used for the capture of prey. Neurotoxins are particularly important in this regard, producing paralysis of skeletal muscles. These neurotoxins can be classified according to their site of action (i.e. pre- or post-synaptic). 2.,Presynaptic neurotoxins, which display varying phospholipase A2 activities, have been identified in the venoms of the four major families of venomous snakes (i.e. Crotalidae, Elapidae, Hydrophiidae and Viperidae). The blockade of transmission produced by these toxins is usually characterized by a triphasic effect on acetylcholine release. Considerable work has been directed at identifying the binding site(s) on the presynaptic nerve terminal for these toxins, although their mechanism of action remains unclear. 3.,Post-synaptic neurotoxins are antagonists of the nicotinic receptor on the skeletal muscle. Depending on their sequence, post-synaptic toxins are subdivided into short- and long-chain toxins. These toxins display different binding kinetics and different affinity for subtypes of nicotinic receptors. Post-synaptic neurotoxins have only been identified in venoms from the families Elapidae and Hydrophiidae. 4.,Due to the high cost of developing new antivenoms and the reluctance of many companies to engage in this area of research, new methodologies are required to test the efficacy of existing antivenoms to ensure their optimal use. While chicken eggs have proven useful for the examination of haemorrhagic venoms, this procedure is not suited to venoms that primarily display neurotoxic activity. The chick biventer cervicis muscle has proven useful for this procedure, enabling the rapid screening of antivenoms against a range of venoms. 5.,Historically, the lethality of snake venoms has been based on murine LD50 studies. Due to ethical reasons, these studies are being superseded by in vitro studies. Instead, the time taken to produce 90% inhibition of nerve-mediated twitches (i.e. t90) in skeletal muscle preparations can be determined. However, these two procedures result in different rank orders because they are measuring two different parameters. While murine LD50 determinations are based on ,quantity', t90 values are based on how ,quick' a venom acts. Therefore, knowledge of both parameters is still desirable. 6.,In vitro neuromuscular preparations have proven to be invaluable tools in the examination of snake venoms and isolated neurotoxins. They will continue to play a role in further elucidating the mechanism of action of these highly potent toxins. Further study of these toxins may provide more highly specific research tools or lead compounds for pharmaceutical agents. [source] Phthalate Esters in Foods: Sources, Occurrence, and Analytical MethodsCOMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 1 2010Xu-Liang Cao ABSTRACT:, Phthalates are a group of diesters of ortho-phthalic acid (dialkyl or alkyl aryl esters of 1,2-benzenedicarboxylic acid). Higher-molecular-weight phthalates, such as di-2-ethylhexyl phthalate (DEHP), are primarily used as plasticizers to soften polyvinyl chloride (PVC) products, while the lower-molecular-weight phthalates, such as diethyl phthalate (DEP), di-n-butyl phthalate (DBP), and butyl benzyl phthalate (BBzP), are widely used as solvents to hold color and scent in various consumer and personal care products. Phthalates have become ubiquitous environmental contaminants due to volatilization and leaching from their widespread applications, and thus contamination of the environment has become another important source for phthalates in foods in addition to migration from packaging materials. Human exposure to phthalates has been an increased concern due to the findings from toxicology studies in animals. DEHP, one of the important and widely used phthalates, is a rodent liver carcinogen. DEHP, DBP, BBzP, and several phthalate metabolites, such as monobutyl phthalate, monobenzyl phthalate, and mono-(2-ethylhexyl) phthalate, are teratogenic in animals. Since foods are the major source of exposure to phthalates, information on levels of phthalates in foods is important for human exposure assessment. The objective of this review is to identify the knowledge gaps for future investigations by reviewing levels of a wide range of phthalates in a variety of foods, such as bottled water, soft drinks, infant formula, human milk, total diet foods, and others, migration of phthalates from various food-packaging materials, and traditional and new methodologies for the determination of phthalates in foods. [source] A social agent pedestrian modelCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 3-4 2008Andrew Park Abstract This paper presents a social agent pedestrian model based on experiments with human subjects. Research studies of criminology and environmental psychology show that certain features of the urban environment generate fear in people, causing them to take alternate routes. The Crime Prevention Through Environmental Design (CPTED) strategy has been implemented to reduce fear of crime and crime itself. Our initial prototype of a pedestrian model was developed based on these findings of criminology research. In the course of validating our model, we constructed a virtual environment (VE) that resembles a well-known fear-generating area where several decision points were set up. 60 human subjects were invited to navigate the VE and their choices of routes and comments during the post interviews were analyzed using statistical techniques and content analysis. Through our experimental results, we gained new insights into pedestrians' behavior and suggest a new enhanced and articulated agent model of a pedestrian. Our research not only provides a realistic pedestrian model, but also a new methodology for criminology research. Copyright © 2008 John Wiley & Sons, Ltd. [source] Multiple animated characters motion fusionCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 5 2002Luo Zhongxiang Abstract One of the major problems of the motion capture-based computer animation technique is the relatively high cost of equipment and low reuse rate of data. To overcome this problem, many motion-editing methods have been developed. However, most of them can only handle one character whose motions are preset, and hence cannot interact with its environment automatically. In this paper, we construct a new architecture of multiple animated character motion fusion, which not only enables the characters to perceive and respond to the virtual environment, but also allows them to interact with each other. We will also discuss in detail the key issues, such as motion planning, coordination of multiple animated characters and generation of vivid continuous motions. Our experimental results will further testify to the effectiveness of the new methodology. Copyright © 2002 John Wiley & Sons, Ltd. [source] Sparse points matching by combining 3D mesh saliency with statistical descriptorsCOMPUTER GRAPHICS FORUM, Issue 2 2008U. Castellani Abstract This paper proposes new methodology for the detection and matching of salient points over several views of an object. The process is composed by three main phases. In the first step, detection is carried out by adopting a new perceptually-inspired 3D saliency measure. Such measure allows the detection of few sparse salient points that characterize distinctive portions of the surface. In the second step, a statistical learning approach is considered to describe salient points across different views. Each salient point is modelled by a Hidden Markov Model (HMM), which is trained in an unsupervised way by using contextual 3D neighborhood information, thus providing a robust and invariant point signature. Finally, in the third step, matching among points of different views is performed by evaluating a pairwise similarity measure among HMMs. An extensive and comparative experimental session has been carried out, considering real objects acquired by a 3D scanner from different points of view, where objects come from standard 3D databases. Results are promising, as the detection of salient points is reliable, and the matching is robust and accurate. [source] Dynamic Wavelet Neural Network for Nonlinear Identification of Highrise BuildingsCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 5 2005Xiaomo Jiang Compared with conventional neural networks, training of a dynamic neural network for system identification of large-scale structures is substantially more complicated and time consuming because both input and output of the network are not single valued but involve thousands of time steps. In this article, an adaptive Levenberg,Marquardt least-squares algorithm with a backtracking inexact linear search scheme is presented for training of the dynamic fuzzy WNN model. The approach avoids the second-order differentiation required in the Gauss,Newton algorithm and overcomes the numerical instabilities encountered in the steepest descent algorithm with improved learning convergence rate and high computational efficiency. The model is applied to two highrise moment-resisting building structures, taking into account their geometric nonlinearities. Validation results demonstrate that the new methodology provides an efficient and accurate tool for nonlinear system identification of high-rising buildings. [source] A new method for the aqueous functionalization of superparamagnetic Fe2O3 nanoparticlesCONTRAST MEDIA & MOLECULAR IMAGING, Issue 6 2008Fernando Herranz Abstract A new methodology for the synthesis of hydrophilic iron oxide nanoparticles has been developed. This new method is based on the direct chemical modification of the nanoparticles' surfactant molecules. Using this methodology both USPIO (ultrasmall super paramagnetic iron oxide) (hydrodynamic size smaller than 50,nm) and SPIO (super paramagnetic iron oxide) (hydrodynamic size bigger than 50,nm) were obtained. In addition, we also show that it is possible to further functionalize the hydrophilic nanoparticles via covalent chemistry in water. The magnetic properties of these nanoparticles were also studied, showing their potential as MRI contrast agents. Copyright © 2008 John Wiley & Sons, Ltd. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||