Home About us Contact
|
Home About us Contact | ||
|
|
||
Potential Utility (potential + utility)
Selected AbstractsTotal Protein Methods and Their Potential Utility to Reduce the Risk of Food Protein AdulterationCOMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 4 2010Jeffrey C. Moore Adulteration incidents exploiting this analytical vulnerability (for example, melamine) demonstrate that these methods are no longer sufficient to protect the public health. This article explores the challenges and opportunities to move beyond total nitrogen based methods for total protein measurement. First, it explores the early history of protein measurement science, complexities of current global protein measurement activities, and ideal analytical performance characteristics for new methods. Second, it comprehensively reviews the pros and cons of current and emerging approaches for protein measurement, including their selectivity for protein, ability to detect adulteration, and practicality for routine use throughout the supply chain. It concludes that some existing highly selective methods for food protein measurement have potential for routine quality control. It also concludes that their successful implementation will require matrix-specific validation and the use of supporting reference materials. These methods may be suitable only for food ingredients that have a low degree of compositional variability and are not complex finished food products. [source] Performance measures in Friedreich ataxia: Potential utility as clinical outcome toolsMOVEMENT DISORDERS, Issue 7 2005David R. Lynch MD Abstract Although several neuroprotective agents have been proposed as potential therapies in Friedreich ataxia (FA), clinical trials of their efficacy are limited by a lack of sensitive outcome measures. We assessed whether performance measures (nine-hole peg test, the timed 25-foot walk, and low-contrast letter acuity) provide valid measures of disease status in FA. Scores for each measure correlated significantly with neurologic disability and disease duration. Rank correlations between scores for performance measures were moderate in magnitude, suggesting that the each test captures separate yet related dimensions of neurological function in FA. Linear regression models demonstrated that scores from the nine-hole peg test and the timed 25-foot walk (after reciprocal transformation) were predicted by age and triplet repeat length in patients with FA. In addition, comparison of the temporal courses of change for each performance measure demonstrated that scores from the timed 25-foot walk change early in the course of FA, nine-hole peg test scores change slowly over the full course of the disorder, and low-contrast letter acuity scores change in the later stages of the disease. Thus, a composite scale derived from these performance measures may provide the best overall measure for assessing disease progression throughout the illness. © 2005 Movement Disorder Society [source] Potential utility of actuarial methods for identifying specific learning disabilitiesPSYCHOLOGY IN THE SCHOOLS, Issue 6 2010Nicholas Benson This article describes how actuarial methods can supplant discrepancy models and augment problem solving and Response to Intervention (RTI) efforts by guiding the process of identifying specific learning disabilities (SLD). Actuarial methods use routinized selection and execution of formulas derived from empirically established relationships to make predictions that fall within a plausible range of possible future outcomes. In the case of SLD identification, the extent to which predictions are reasonable can be evaluated by their ability to categorize large segments of the population into subgroups that vary considerably along a spectrum of risk for academic failure. Although empirical comparisons of actuarial methods to clinical judgment reveal that actuarial methods consistently outperform clinical judgment, multidisciplinary teams charged with identifying SLD currently rely on clinical judgment. Actuarial methods provide educators with an empirically verifiable indicator of student need for special education and related services that could be used to estimate the relative effects of exclusionary criteria. This indicator would provide a defensible endpoint in the process of identifying SLD as well as a means of informing and improving the SLD identification process. © 2010 Wiley Periodicals, Inc. [source] Real-Time Liquid Crystal pH Sensor for Monitoring Enzymatic Activities of PenicillinaseADVANCED FUNCTIONAL MATERIALS, Issue 23 2009Xinyan Bi Abstract A liquid crystal (LC)-based pH sensor for real-time monitoring of changes in localized pH values near a solid surface is reported, along with its application for the detection of enzymatic activities. It is found that 4-cyano-4,-pentylbiphenyl (5CB), when doped with 4,-pentyl-biphenyl-4-carboxylic acid (PBA), shows a bright-to-dark optical response to a very small change in pH (from 6.9 to 7.0). The pH-driven optical response can be explained by using orientational transitions of 5CB induced by the protonation and deprotonation of PBA at the aqueous/LC interface. Because of its high pH sensitivity, the LC-based sensor is further exploited for monitoring local pH changes resulting from enzymatic reactions. As a proof of concept, the hydrolysis of penicillin G by surface-immobilized penicillinase is monitored using the system, even when the concentration of penicillin G is as low as 1,nM. This type of LC-based sensor may find potential utilities in high-throughput screening of enzyme substrates and enzyme inhibitors. [source] Benzo[b]phosphole-Containing ,-Electron Systems: Synthesis Based on an Intramolecular trans -Halophosphanylation and Some Insights into Their PropertiesCHEMISTRY - AN ASIAN JOURNAL, Issue 11 2009Aiko Fukazawa Dr. Abstract The intramolecular trans -halophosphanylation of 2-(aminophosphanyl)phenylacetylenes mediated by PBr3 followed by the oxidation with H2O2, produces 3-bromobenzo[b]phosphole oxide derivatives. This cyclization is also used for the synthesis of a 3-iodo derivative by conducting the reaction in the presence of LiI. Based on this synthetic method, various benzophosphole-containing ,-conjugated compounds, including a phosphoryl and methylene-bridged stilbene 10, 2,3,6,7-tetraphenylbenzo[1,2- b:4,5- b,]diphosphole- P,P, -dioxides 11, and their phosphine sulfide derivatives 12, are synthesized. The study of the structure,property relationships in a series of the bridged stilbenes, including a bis(methylene)-bridged stilbene 10, and a bis(phosphoryl)-bridged stilbene, reveals that as the contribution of the phosphoryl groups increased, the absorption and emission maxima substantially shift to longer wavelengths. The intrinsic substituent effects of the phosphoryl group in this skeleton are to decrease the oscillator strength of the electronic transition and thus decrease the radiative decay rate constants from the singlet excited state. Nevertheless, these compounds maintain high fluorescence quantum yields (,F>0.8) owing to the significantly retarded nonradiative decay process. In the study of the benzodiphosphole derivatives 11 and 12, their cyclic voltammetry revealed that both of the phosphoryl and phosphine sulfide derivatives have low reduction potentials (,1.7 to ,1.8,V vs ferrocene/ferrocenium couple) with the high reversibility of the redox waves. These compounds also showed high thermal stabilities with the high glass transition temperatures of 147,159,°C, indicative of their potential utilities as amorphous materials. [source] MRI tumor characterization using Gd-GlyMe-DOTA-perfluorooctyl-mannose-conjugate (Gadofluorine MÔ), a protein-avid contrast agentCONTRAST MEDIA & MOLECULAR IMAGING, Issue 3 2006Hans-Jürgen Raatschen Abstract The rationale and objectives were to define the MRI tumor-characterizing potential of a new protein-avid contrast agent, Gd-GlyMe-DOTA-perfluorooctyl-mannose-conjugate (Gadofluorine MÔ; Schering AG, Berlin, Germany) in a chemically induced tumor model of varying malignancy. Because of the tendency for this agent to form large micelles in water and to bind strongly to hydrophobic sites on proteins, it was hypothesized that patterns of dynamic tumor enhancement could be used to differentiate benign from malignant lesions, to grade the severity of malignancies and to define areas of tumor necrosis. Gadofluorine M, 0.05,mmol,Gd,kg,1, was administered intravenously to 28 anesthetized rats that had developed over 10 months mammary tumors of varying degrees of malignancy as a consequence of intraperitoneal administration of N -ethyl- N -nitrosourea (ENU), 45,250,mg,kg,1. These tumors ranged histologically from benign fibroadenomas to highly undifferentiated adenocarcinomas. Dynamic enhancement data were analyzed kinetically using a two-compartment tumor model to generate estimates of fractional plasma volume (fPV), apparent fractional extracellular volume (fEV*) and an endothelial transfer coefficient (KPS) for this contrast agent. Tumors were examined microscopically for tumor type, degree of malignancy (Scarff,Bloom,Richardson score) and location of necrosis. Eighteen tumor-bearing rats were successfully imaged. MRI data showed an immediate strong and gradually increasing tumor enhancement. KPS and fEV*, but not fPV obtained from tumors correlated significantly (p,<,0.05) with the SBR tumor grade, r,=,0.65 and 0.56, respectively. Estimates for KPS and fEV* but not fPV were significantly lower in a group consisting of benign and low-grade malignant tumors compared with the group of less-differentiated high-grade tumors (1.61,±,0.64 vs 3.37,±,1.49, p,<,0.01; 0.45,±,0.17 vs 0.78,±,0.24, p,<,0.01; and 0.076,±,0.048 vs 0.121,±,0.088, p,=,0.24, respectively). It is concluded that the protein-avid MRI contrast agent Gadofluorine M enhances tumors of varying malignancy depending on the tumor grade, higher contrast agent accumulation for more malignant lesions. The results show potential utility for differentiating benign and low-grade malignant lesions from high-grade cancers. Copyright © 2006 John Wiley & Sons, Ltd. [source] Making a Difference in the Lives of Youth: Mapping Success with the "Six Cs"CURATOR THE MUSEUM JOURNAL, Issue 4 2007Jessica J. Luke Many museums offer specialized programs for young people during out-of-school time, yet the consequences of such programs are not well documented. This article explores the potential utility of borrowing a conceptual framework from the youth development literature as a tool for assessment. The authors map findings from three studies of museum youth programs onto the youth development framework as an exercise in understanding the extent to which this model may be useful in developing museum youth programs. Results from this preliminary analysis demonstrate that the framework could serve as a viable tool for program design, and could offer a clear, grounded framework with common language for articulating program impacts often known intuitively and/or anecdotally but not formalized. [source] Screening for diabetes in Indigenous populations using glycated haemoglobin: sensitivity, specificity, post-test likelihood and risk of diseaseDIABETIC MEDICINE, Issue 7 2005K. G. Rowley Abstract Aims Screening for diabetes using glycated haemoglobin (HbA1c) offers potential advantages over fasting glucose or oral glucose tolerance testing. Current recommendations advise against the use of HbA1c for screening but test properties may vary systematically across populations, according to the diabetes prevalence and risk. We aimed to: (i) characterize the properties of test cut-offs of HbA1c for diagnosis of diabetes relative to a diagnosis based on a fasting plasma glucose concentration of 7.0 mmol/l for high-risk Indigenous populations; and (ii) examine test properties across a range of diabetes prevalence from 5 to 30%. Methods Data were collected from Aboriginal and Torres Strait Islander communities in Australia and a Canadian First Nations community (diabetes prevalence 12,22%) in the course of diabetes diagnostic and risk factor screening programmes (n = 431). Screening test properties were analyzed for the range of HbA1c observed (3,12.9%). Results In separate and pooled analyses, a HbA1c cut point of 7.0% proved the optimal limit for classifying diabetes, with summary analysis results of sensitivity = 73 (56,86)%, specificity = 98 (96,99)%, overall agreement (Youden's index) = 0.71, and positive predictive value (for an overall prevalence of 18%) = 88%. For diabetes prevalence from 5 to 30% the post-test likelihood of having diabetes given HbA1c = 7.0% (positive predictive value) ranged from 62.7 to 93.2%; for HbA1c < 7.0%, the post-test likelihood of having diabetes ranged from 4.5 to 27.7%. Conclusions The results converge with research on the likelihood of diabetes complications in supporting a HbA1c cut-off of 7.0% in screening for diabetes in epidemiological research. Glycated haemoglobin has potential utility in screening for diabetes in high-risk populations. [source] In vitro and in vivo characterization of TC-1827, a novel brain ,4,2 nicotinic receptor agonist with pro-cognitive activityDRUG DEVELOPMENT RESEARCH, Issue 1 2004Georg Andrees Bohme Abstract Nicotine activates specific receptors that are cation-permeable ionic channels located in the central and autonomous nervous systems, as well as at the neuromuscular junction. Administration of nicotine to animals and humans has been shown to enhance cognitive processes. However, side effects linked to the activation of peripheral nicotinic receptors limit the usefulness of nicotine for the treatment of cognitive disorders such as Alzheimer's disease (AD) or mild cognitive impairments (MCI). The synthesis and properties of TC-1827, a novel metanicotine derivative that activates brain ,4,2 nicotinic receptors is described. TC-1827 has high affinity for nicotine-labeled receptors in the cortex (Ki=34 nM), full-agonist intrinsic activity in ,4,2 -mediated neurotransmitter release studies in synaptosomes, and has no functional activity at nicotinic receptors in ganglionic or muscular cell lines. The compound enhances long-term potentiation in hippocampal slices, a form of synaptic plasticity thought to be involved in information storage at the cellular level. In vivo studies demonstrate that TC-1827 dose-dependently occupies thalamic nicotinic receptors labeled with [3H]-cytisine, increases cortical extracellular acetylcholine levels following oral administration, and enhances cognitive performance in rat and mice behavioral procedures of learning and memory. Pharmacokinetic studies in mice, rats, and monkeys indicated that TC-1827 has good oral absorption with a first pass effect resulting in bioavailabilities of 13,65% across dose/species. Cardiovascular safety studies indicate good cardiovascular tolerability for this compound. The present data demonstrate that TC-1827 is a selective and potent activator of brain ,4,2 nicotinic receptors and is a prototypical member of a new class of compounds with potential utility in the symptomatic treatment of cognitive disorders including AD and MCI. Drug Dev. Res. 62:26,40, 2004. © 2004 Wiley-Liss, Inc. [source] Behavioral economic analysis of cue-elicited craving for alcoholADDICTION, Issue 9 2010James MacKillop ABSTRACT Aims Craving as a motivational determinant of drug use remains controversial because of ambiguous empirical findings. A behavioral economic approach may clarify the nature of craving, theorizing that subjective craving functionally reflects an acute increase in a drug's value. The current study tested this hypothesis via a multidimensional assessment of alcohol demand over the course of an alcohol cue reactivity procedure. Design One-way within-subjects design. Setting Human laboratory environment. Participants Heavy drinkers (n = 92) underwent exposures to neutral (water) cues followed by personalized alcohol cues. Assessments Participants were assessed for craving, alcohol demand, affect, and salivation following each exposure. Findings Alcohol versus neutral cues significantly increased craving and multiple behavioral economic measures of the relative value of alcohol, including alcohol consumption under conditions of zero cost (intensity), maximum expenditure on alcohol (Omax), persistence in drinking to higher prices (breakpoint) and proportionate price insensitivity (normalized Pmax). Craving was significantly correlated with demand measures at levels ranging from 0.21,0.43. Conclusions These findings support the potential utility of a behavioral economic approach to understanding the role of environmental stimuli in alcohol-related decision making. Specifically, they suggest that the behavioral economic indices of demand may provide complementary motivational information that is related to though not entirely redundant with measures of subjective craving. [source] Modelling species distributions in Britain: a hierarchical integration of climate and land-cover dataECOGRAPHY, Issue 3 2004Richard G. Pearson A modelling framework for studying the combined effects of climate and land-cover changes on the distribution of species is presented. The model integrates land-cover data into a correlative bioclimatic model in a scale-dependent hierarchical manner, whereby Artificial Neural Networks are used to characterise species' climatic requirements at the European scale and land-cover requirements at the British scale. The model has been tested against an alternative non-hierarchical approach and has been applied to four plant species in Britain: Rhynchospora alba, Erica tetralix, Salix herbacea and Geranium sylvaticum. Predictive performance has been evaluated using Cohen's Kappa statistic and the area under the Receiver Operating Characteristic curve, and a novel approach to identifying thresholds of occurrence which utilises three levels of confidence has been applied. Results demonstrate reasonable to good predictive performance for each species, with the main patterns of distribution simulated at both 10 km and 1 km resolutions. The incorporation of land-cover data was found to significantly improve purely climate-driven predictions for R. alba and E. tetralix, enabling regions with suitable climate but unsuitable land-cover to be identified. The study thus provides an insight into the roles of climate and land-cover as determinants of species' distributions and it is demonstrated that the modelling approach presented can provide a useful framework for making predictions of distributions under scenarios of changing climate and land-cover type. The paper confirms the potential utility of multi-scale approaches for understanding environmental limitations to species' distributions, and demonstrates that the search for environmental correlates with species' distributions must be addressed at an appropriate spatial scale. Our study contributes to the mounting evidence that hierarchical schemes are characteristic of ecological systems. [source] The promise and the potential consequences of the global transport of mycorrhizal fungal inoculumECOLOGY LETTERS, Issue 5 2006Mark W. Schwartz Abstract Advances in ecology during the past decade have led to a much more detailed understanding of the potential negative consequences of species' introductions. Moreover, recent studies of mycorrhizal symbionts have led to an increased knowledge of the potential utility of fungal inoculations in agricultural, horticultural and ecological management. The intentional movement of mycorrhizal fungal species is growing, but the concomitant potential for negative ecological consequences of invasions by mycorrhizal fungi is poorly understood. We assess the degree to which introductions of mycorrhizal fungi may lead to unintended negative, and potentially costly, consequences. Our purpose is to make recommendations regarding appropriate management guidelines and highlight top priority research needs. Given the difficulty in discerning invasive species problems associated with mycorrhizal inoculations, we recommend the following. First, careful assessment documenting the need for inoculation, and the likelihood of success, should be conducted prior to inoculation because inoculations are not universally beneficial. Second, invasive species problems are costly and often impossible to control by the time they are recognized. We recommend using local inoculum sources whenever possible. Third, non-sterile cultures of inoculum can result in the movement of saprobes and pathogens as well as mutualists. We recommend using material that has been produced through sterile culture when local inoculum is not available. Finally, life-history characteristics of inoculated fungi may provide general guidelines relative to the likelihood of establishment and spread. We recommend that, when using non-local fungi, managers choose fungal taxa that carry life-history traits that may minimize the likelihood of deleterious invasive species problems. Additional research is needed on the potential of mycorrhizal fungi to spread to non-target areas and cause ecological damage. [source] Design, characterization, and utilization of a fast fluorescence derivatization reaction utilizing o -phthaldialdehyde coupled with fluorescent thiolsELECTROPHORESIS, Issue 7 2007Suminda Hapuarachchi Abstract We have developed a chemical derivatization scheme for primary amines that couples the fast kinetic properties of o -phthaldialdehyde (OPA) with the photophysical properties of visible, high quantum yield, fluorescent dyes. In this reaction, OPA is used as a cross-linking reagent in the labeling reaction of primary amines in the presence of a fluorescent thiol, 5-((2-(and-3)- S -(acetylmercapto)succinoyl)amino)fluorescein (SAMSA fluorescein), thereby incorporating fluorescein (,,=,78,000,M,1, quantum yield of 0.98) into the isoindole product. Detection is based on excitation and emission of the incorporated fluorescein using the 488,nm laser line of an Ar+ laser rather than the UV-excited isoindole, thereby eliminating the UV light sources for detection. Using this method, we have quantitatively labeled biologically important primary amines in less than 10,s. Detection limits for analysis of glutamate, glycine, GABA, and taurine were less than 2,nM. We present the characterization of OPA/SAMSA-F reaction and the potential utility of the derivatization reaction for dynamic chemical monitoring of biologically relevant analytes using CE. [source] The Prestige oil spill.ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2005Abstract In vitro biodegradation of the Prestige heavy fuel oil has been carried out using two microbial consortia obtained by enrichment in different substrates to simulate its environmental fate and potential utility for bioremediation. Different conditions, such as incubation time (i.e., 20 or 40 d), oil weathering, and addition of an oleophilic fertilizer (S200), were evaluated. Weathering slowed down the degradation of the fuel oil, probably because of the loss of lower and more labile components, but the addition of S200 enhanced significantly the extension of the biodegradation. n -Alkanes, alkylcyclohexanes, alkylbenzenes, and the two- to three-ring polycyclic aromatic hydrocarbons (PAHs) were degraded in 20 or 40 d of incubation of the original oil, whereas the biodegradation efficiency decreased for higher PAHs and with the increase of alkylation. Molecular markers were degraded according to the following sequence: Acyclic isoprenoids < diasteranes < C27 -steranes < ,,-steranes < homohopanes < monoaromatic steranes < triaromatic steranes. Isomeric selectivity was observed within the C1 - and C2 -phenanthrenes, dibenzothiophenes, pyrenes, and chrysenes, providing source and weathering indices for the characterization of the heavy oil spill. Acyclic isoprenoids, C27 -steranes, C1 - and C2 -naphthalenes, phenanthrenes, and dibenzothiophenes were degraded completely when S200 was used. The ratios of the C2 - and C3 -alkyl homologues of fluoranthene/pyrene and chrysene/benzo[a]anthracene are proposed as source ratios in moderately degraded oils. The 4-methylpyrene and 3-methylchrysene were refractory enough to serve as conserved internal markers in assessing the degradation of the aromatic fraction in a manner similar to that of hopane, as used for the aliphatic fraction. [source] Concurrent validity of the Alcohol Use Disorders Identification Test (AUDIT) and AUDIT zones in defining levels of severity among out-patients with alcohol dependence in the COMBINE studyADDICTION, Issue 12 2006Dennis M. Donovan ABSTRACT Aims To examine among alcohol-dependent out-patient clients the concurrent validity of the Alcohol Use Disorders Identification Test (AUDIT) total score and ,zones' suggested by the World Health Organization for defining levels of severity of alcohol use problems. Design Participants were classified into AUDIT zones (AUDIT total score = 8,15, 16,19, 20,40) and compared on measures of demographics, treatment goals, alcohol consumption, alcohol-related consequences, severity of dependence, physiological dependence, tolerance, withdrawal and biomarkers of alcohol use. Setting Eleven out-patient academic clinical research centers across the United States. Participants Alcohol dependent individuals (n = 1335) entering out-patient treatment in the Combined Pharmacotherapies and Behavioral Interventions (COMBINE) study. Measurements The AUDIT was administered as part of an initial screening. Baseline measures used for concurrent validation included the Structured Clinical Interview for Diagnostic and Statistical Manual, 4th edition (DSM-IV) Disorders, the Alcohol Dependence Scale, the Drinker Inventory of Consequences, the Obsessive-Compulsive Drinking Scale, the University of Rhode Island Change Assessment, the Thoughts about Abstinence Scale, the Form-90, %carbohydrate-deficient transferrin and gamma-glutamyl transferase. Findings Indicators of severity of dependence and alcohol-related problems increased linearly with total score and differed significantly across AUDIT zones. The highest zone, with scores of 20 and above, was markedly different with respect to severity from the other two zones and members of this group endorsed an abstinence goal more strongly. Conclusions The AUDIT total score is a brief measure that appears to provide an index of severity of dependence in a sample of alcohol-dependent individuals seeking out-patient treatment, extending its potential utility beyond its more traditional role as a screening instrument in general populations. [source] Cocaine Rapid Efficacy Screening Trial (CREST): a paradigm for the controlled evaluation of candidate medications for cocaine dependenceADDICTION, Issue 2005Deborah B. Leiderman ABSTRACT Aim Development of effective medications for the treatment of cocaine dependence remains a major priority for the National Institute on Drug Abuse (NIDA) at the National Institutes of Health. The Cocaine Rapid Efficacy Screening Trial (CREST) paradigm was developed by the Division of Treatment Research and Development (DT R&D) at NIDA with the goal of enhancing pilot clinical trial validity when systematically assessing a range of medications and drug classes for potential utility in treatment of cocaine dependence. Design CREST utilizes a randomized, controlled, parallel group, blinded methodology for comparing one or more marketed medications against a standard, pharmaceutical grade placebo. The trial design is comprised of a flexible 2,4-week screening/baseline period followed by randomization to an 8-week treatment period. Measures Standard measures of outcomes for the CREST included urinary benzoylecgonine (primary metabolite of cocaine), retention, cocaine craving, depression, clinical global impression and HIV-risk behaviors. In order to facilitate comparisons of data from the CREST studies across sites, drug classes and time, standardized procedures, measures and psychosocial counseling were used. Results A total of 19 medications were evaluated in out-patient treatment research clinics in Boston, Cincinnati, Los Angeles, New York and Philadelphia. Conclusions Findings supported decisions to move forward three medications (cabergoline, reserpine, tiagabine) using full-scale, adequately powered, randomized placebo-controlled trial designs. Lessons learned from the CREST experience continue to shape cocaine pharmacotherapy trial design and execution. [source] New Heterodimetallic Platinum(II) Complexes Potentially Useful as Molecular SwitchesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 10 2008Sonia Pérez Abstract Four types of platinum(II) complexes of general formulae [Pt(FcCH=NC6H4OH-2)Cl2(L)] [Fc = (,5 -C5H5)Fe(,5 -C5H4), L = dmso (2) or PhCN (3)], [Pt(FcCH=NC6H4O-2)Cl(dmso)] (4), [Pt{(,5 -C5H3CH=NC6H4O-2)Fe(,5 -C5H5)}(L)] [L = dmso (5) or PPh3 (6)] or [Pt{(,5 -C5H3CH=NC6H4OH-2)Fe(,5 -C5H5)}Cl(L)] [L = dmso (7) or PPh3 (8)] have been prepared. These compounds differ in the mode of binding of the ligand: (N) (in 2 and 3), (N,O), (in 4), [C(sp2, ferrocene),N,O]2, (in 5 and 6) or [C(sp2, ferrocene),N], (in 7 and 8). NMR, UV/Vis and electrochemical studies of 2 and 4,8 reveal that these products can be grouped in three pairs [(2c, 4b), (5, 7) and (6, 8)], and one of the compounds of each pair can be easily converted into its partner by a H+/OH, chemical input. The results obtained revealed that these transformations, that affect the spectroscopic and electrochemical properties, are reversible and robust. A study of the relevancy of the mode of binding of compounds 2 and 4,8 upon their potential utility of the new platinum(II) complexes as molecular switches is reported. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Using Videotaped Feedback During Intervention With Married Couples: A Qualitative AssessmentFAMILY RELATIONS, Issue 4 2006Edgar C. J. Long Abstract: Sixteen married couples volunteered to participate in a 6-week empathy training program. Ten of the 16 couples observed and made comments about their taped interaction at the end of the program. Individuals watched the tape of their own interaction at the follow-up and were asked several qualitative questions, including what they noticed about themselves. The five themes that emerged in the comments individuals made after watching themselves on videotape included surprised by self, discomfort watching the tape, increased self-awareness of emotions, observed patterns of interaction, and nondefensive self-disclosure. We discuss the potential utility of the videotape methodology for marriage educators and interventionists. [source] Classifying tagging experiments for commercial fisheries into three fundamental types based on design, data requirements and estimable population parametersFISH AND FISHERIES, Issue 2 2010Tom Polacheck Abstract Mark,recapture experiments have the potential to provide direct estimates of fundamental parameters required for fishery stock assessment and provision of subsequent management advice in fisheries. The literature on mark,recapture experiments is enormous, with a variety of different experimental designs and estimation models; thus, it can be difficult to grasp the primary features of different approaches, the inter-relationship among them and their potential utility in different situations. Here, we present an overview of the tagging experimental designs that are appropriate for use in commercial fishery situations. We suggest that most mark,recapture experiments in a large-scale fishery context can be classified into one of three basic types , Petersen, tag-attrition or Brownie , based on the fundamental design employed for releases and recaptures. The release and recapture strategy (e.g. the number of release events, whether the size of the sample examined for recaptured tags is known) determines which parameters can be estimated and from where the information for estimating them arises. We conclude that an integrated Brownie and Petersen approach is the most powerful of the different approaches in terms of the range of parameters that can be estimated without underlying assumptions or constraints on parameters. Such an approach can provide direct estimates of fishing mortality, natural mortality and population size, which are the main population dynamics parameters that traditional fishery stock assessments attempt to estimate. [source] Can taxonomic distinctness assess anthropogenic impacts in inland waters?FRESHWATER BIOLOGY, Issue 9 2006A case study from a Mediterranean river basin Summary 1. It is increasingly recognised that adequate measures of biodiversity should include information on the ,relatedness' of species within ecological assemblages, or the phylogenetic levels at which diversity is expressed. Taxonomic distinctness measures provide a series of indices to achieve this, which are independent of sample size. Taxonomic distinctness has been employed widely in marine systems, where it has been suggested that this index can provide a reliable measure of anthropogenic impact. 2. We tested the behaviour of three related taxonomic distinctiveness indices (Average Taxonomic Distinctness, ,+; Variation in Taxonomic Distinctness, ,+; and Total Taxonomic Distinctness, s,+) in relation to putative levels of anthropogenic impact in inland waters and their potential utility in environmental monitoring, using an extensive data set for aquatic beetles from the south-east of the Iberian Peninsula. 3. Taxonomic distinctness measures were not able to identify human disturbance effects and there were no clear relationships between these new biodiversity measures and the disturbance level recorded at individual localities. Furthermore, the taxonomic distinctness measures used were apparently less sensitive to the effects of anthropogenic impact than other diversity metrics, such as species richness and rarity. 4. We conclude that taxonomic distinctness indices may not always perform as well as other metrics in the assessment of environmental quality. In addition, taxonomic distinctness measure should be interpreted with caution, as their performance and ability to detect anthropogenic disturbance may depend on the phylogenetic structure of sampled taxa within a region, and their evolutionary and ecological history. [source] Fluorescent Imaging: Surface Modification of Exfoliated Layered Gadolinium Hydroxide for the Development of Multimodal Contrast Agents for MRI and Fluorescence Imaging (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 21 2009Mater. The synthesis of a new stable colloid of fluorescent LGdH layers through a newly developed surface modification method is reported by Y.-S. Yoon et al. on page 3375. This new method involves layer exfoliation, anion exchange, and PEG coating. The efficient MRI contrast-enhancement of these LGdH layers, both in vitro and in vivo, demonstrates their potential utility as a multimodal probe combining optical and MR imaging. [source] Surface Modification of Exfoliated Layered Gadolinium Hydroxide for the Development of Multimodal Contrast Agents for MRI and Fluorescence ImagingADVANCED FUNCTIONAL MATERIALS, Issue 21 2009Young-su Yoon Abstract A novel method for modifying the surface of magnetic-resonance-contrasting layered gadolinium hydroxide (LGdH) is developed providing them with water- and bio-compatibility and acid-resistance, all of which are essential for medical applications. A stable colloid of exfoliated layers is synthesized by exchanging interlayer anions of LGdH with oleate ions. The delaminated layers are successively coated with phospholipids with poly(ethylene glycol) tail groups, and their effectiveness as a contrast agent for magnetic resonance imaging (MRI) is demonstrated. The adaptability of this surface modification approach for incorporating functional molecules and fabricating a fluorescent colloid of LGdH, which has the potential utility as a multimodal probe, is also demonstrated. This result provides a novel approach for expanding the applications of layered inorganic materials and developing a new class of MRI contrast agents. [source] Modelling patterned ground distribution in Finnish Lapland: an integration of topographical, ground and remote sensing informationGEOGRAFISKA ANNALER SERIES A: PHYSICAL GEOGRAPHY, Issue 1 2006Jan Hjort Abstract New data technologies and modelling methods have gained more attention in the field of periglacial geomorphology during the last decade. In this paper we present a new modelling approach that integrates topographical, ground and remote sensing information in predictive geomorphological mapping using generalized additive modelling (GAM). First, we explored the roles of different environmental variable groups in determining the occurrence of non-sorted and sorted patterned ground in a fell region of 100 km2 at the resolution of 1 ha in northern Finland. Second, we compared the predictive accuracy of ground-topography- and remote-sensing-based models. The results indicate that non-sorted patterned ground is more common at lower altitudes where the ground moisture and vegetation abundance is relatively high, whereas sorted patterned ground is dominant at higher altitudes with relatively high slope angle and sparse vegetation cover. All modelling results were from good to excellent in model evaluation data using the area under the curve (AUC) values, derived from receiver operating characteristic (ROC) plots. Generally, models built with remotely sensed data were better than ground-topography-based models and combination of all environmental variables improved the predictive ability of the models. This paper confirms the potential utility of remote sensing information for modelling patterned ground distribution in subarctic landscapes. [source] HCV796: A selective nonstructural protein 5B polymerase inhibitor with potent anti-hepatitis C virus activity In Vitro, in mice with chimeric human livers, and in humans infected with hepatitis C virus,HEPATOLOGY, Issue 3 2009Norman M. Kneteman Anti-hepatitis C virus (HCV) drug development has been challenged by a lack of experience with inhibitors inclusive of in vitro, animal model, and clinical study. This manuscript outlines activity and correlation across such a spectrum of models and into clinical trials with a novel selective nonstructural protein 5B (NS5B) polymerase inhibitor, HCV796. Enzyme assays yielded median inhibitory concentration (IC50) values of 0.01 to 0.14 ,M for genotype 1, with half maximal effective concentration (EC50s) of 5 nM and 9 nM against genotype 1a and 1b replicons. In the chimeric mouse model, a 2.02 ± 0.55 log reduction in HCV titer was seen with monotherapy, whereas a suboptimal dose of 30 mg/kg three times per day in combination with interferon demonstrated a 2.44 log reduction (P = 0.001 versus interferon alone) Clinical outcomes in combination with pegylated interferon and ribavirin have revealed additive efficacy in treatment naïve patients. Abnormal liver function test results were observed in 8% of HCV-796 patients treated for over 8 weeks, resulting in suspension of further trial activity. Conclusion: The RNA-dependent RNA polymerase inhibitor HCV796 demonstrated potent anti-HCV activity consistently through enzyme inhibition assays, subgenomic replicon, and chimeric mouse studies. Strong correlations of outcomes in the mouse model were seen with subsequent clinical trials, including a plateau in dose-related antiviral activity and additive impact from combination therapy with interferon. These outcomes demonstrate the utility of the range of in vitro and in vivo models now available for anti-HCV drug development and support the potential utility of polymerase inhibitors in future combination therapies for HCV treatment. (HEPATOLOGY 2009.) [source] Angiotensin II type 1 receptor blocker inhibits fibrosis in rat nonalcoholic steatohepatitis,HEPATOLOGY, Issue 6 2007Akira Hirose Nonalcoholic steatohepatitis (NASH) is now the most frequent cause of chronic liver impairment in developed countries and is a suggested causative factor in the development of cryptogenic cirrhosis and hepatocellular carcinoma. At present there is no effective and accepted therapy for NASH. The renin-angiotensin system is involved in hepatic fibrosis through activation of hepatic stellate cells, major fibrogenic cells in the liver. Hepatic stellate cells are activated by liver injury to express excessive matrix proteins and profibrogenic cytokines such as transforming growth factor,beta 1. Medicines that inhibit this pathway may be of therapeutic potential in NASH. Using a methionine-choline,deficient rat model of NASH, we studied the potential utility of an angiotensin II type 1 receptor blocker (ARB), olmesartan, on biochemical, histologic, and antioxidant measures of disease activity. ARB significantly attenuated increases in aspartate aminotransferase, activation of hepatic stellate cells, oxidative stress, expression of transforming growth factor,beta 1, expression of collagen genes, and liver fibrosis. Conclusion: Our observations strongly suggest a potential preventive role for ARB in the progression of nonalcoholic steatohepatitis. (HEPATOLOGY 2007.) [source] Glass-Forming Cholesteric Liquid Crystal Oligomers for New Tunable Solid-State LaserADVANCED MATERIALS, Issue 8 2010Seiichi Furumi A new potential utility of glass-forming cholesteric liquid crystal (G-CLC) oligomers for application in tunable solid-state laser is presented. The G-CLC is capable of tuning the photonic band gaps (PBGs) by way of the annealing temperature and preserving the tuned PBGs by a subsequent supercooling treatment. This G-CLC film enables the facile fabrication of a continuously gradated PGB structure and, thus, the continuous tuning of a single laser-emission peak (see figure). [source] Improving functional magnetic resonance imaging motor studies through simultaneous electromyography recordingsHUMAN BRAIN MAPPING, Issue 9 2007Bradley J. MacIntosh Abstract Specially designed optoelectronic and data postprocessing methods are described that permit electromyography (EMG) of muscle activity simultaneous with functional MRI (fMRI). Hardware characterization and validation included simultaneous EMG and event-related fMRI in 17 healthy participants during either ankle (n = 12), index finger (n = 3), or wrist (n = 2) contractions cued by visual stimuli. Principal component analysis (PCA) and independent component analysis (ICA) were evaluated for their ability to remove residual fMRI gradient-induced signal contamination in EMG data. Contractions of ankle tibialis anterior and index finger abductor were clearly distinguishable, although observing contractions from the wrist flexors proved more challenging. To demonstrate the potential utility of simultaneous EMG and fMRI, data from the ankle experiments were analyzed using two approaches: 1) assuming contractions coincided precisely with visual cues, and 2) using EMG to time the onset and offset of muscle contraction precisely for each participant. Both methods produced complementary activation maps, although the EMG-guided approach recovered more active brain voxels and revealed activity better in the basal ganglia and cerebellum. Furthermore, numerical simulations confirmed that precise knowledge of behavioral responses, such as those provided by EMG, are much more important for event-related experimental designs compared to block designs. This simultaneous EMG and fMRI methodology has important applications where the amplitude or timing of motor output is impaired, such as after stroke. Hum Brain Mapp 2006. © 2006 Wiley-Liss, Inc. [source] An observational measure of children's behavioural style: Evidence supporting a multi-method approach to studying temperamentINFANT AND CHILD DEVELOPMENT, Issue 2 2004Jennifer Karp Abstract This study demonstrates the potential utility of the Behavioural Style Observational System (BSOS) as a new observational measure of children's behavioural style. The BSOS is an objective, short and easy to use measure that can be readily adapted to a variety of home and laboratory situations. In the present study, 160 mother,child dyads from the Concordia Longitudinal Risk Project (CLRP) were observed during an 11-min behavioural sample. Videotaped interactions were coded using the BSOS for children's mood, activity level, vocal reactivity, approach to toys, mood consistency and adaptability. Comparisons between the BSOS observational ratings and mothers' ratings of the child on the EAS Temperament Survey (EAS) provided support for modest congruence between these two measurement systems, and revealed a differential predictive pattern of children's functioning. Specifically, the observation-based BSOS predicted children's cognitive performance and adaptive behaviour during testing, whereas the mother-rated EAS predicted maternal ratings of children's internalizing and externalizing behaviour problems. Both measures were found to independently predict mothers' ratings of parenting stress. Overall, the findings imply that neither observational measures nor maternal ratings alone are sufficient to understand children's behavioural style, and that comprehensive evaluations of children's temperament should optimally include both types of measures. Copyright © 2004 John Wiley & Sons, Ltd. [source] Comparison of suitable drought indices for climate change impacts assessment over Australia towards resource managementINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 10 2008F. Mpelasoka Abstract Droughts have significant environmental and socio-economic impacts in Australia. This emphasizes Australia's vulnerability to climate variability and limitations of adaptive capacity. Two drought indices are compared for their potential utility in resource management. The Rainfall Deciles-based Drought Index is a measure of rainfall deficiency while the Soil-Moisture Deciles-based Drought Index is a measure of soil-moisture deficiency attributed to rainfall and potential evaporation. Both indices were used to assess future drought events over Australia under global warming attributed to low and high greenhouse gas emission scenarios (SRES B1 and A1F1 respectively) for 30-year periods centred on 2030 and 2070. Projected consequential changes in rainfall and potential evaporation were based on results from the CCCma1 and Mk2 climate models, developed by the Canadian Climate Center and the Australian Commonwealth Scientific and Industrial Research Organisation (CSIRO) respectively. A general increase in drought frequency associated with global warming was demonstrated by both indices for both climate models, except for the western part of Australia. Increases in the frequency of soil-moisture-based droughts are greater than increases in meteorological drought frequency. By 2030, soil-moisture-based drought frequency increases 20,40% over most of Australia with respect to 1975,2004 and up to 80% over the Indian Ocean and southeast coast catchments by 2070. Such increases in drought frequency would have major implications for natural resource management, water security planning, water demand management strategies, and drought relief payments. Copyright © 2007 Royal Meteorological Society [source] Two-stage kinetic analysis of fragrance evaporation and absorption from skinINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 5 2003P. Saiyasombati Synopsis Human in vivo fragrance evaporation data from a previously published study are reanalysed in terms of compartmental pharmacokinetic models in which the microscopic rate constants are functions of the physicochemical properties of the fragrance components. According to the proposed analysis, which is restricted to low doses, absorption and evaporation of each component are first-order processes occurring from either the skin (one-compartment model) or the skin and a more rapidly depleted vehicle layer (two-compartment models). Evaporation rates of ingredients from a 12-component mixture containing a musk fixative followed single exponential decays that were well described by the one-compartment model. An otherwise identical mixture without fixative yielded evaporation rates that could be characterized as biexponential decays associated with loss from two compartments. This result shows that ingredient interactions qualitatively and quantitatively change evaporation rate profiles of fragrance components; however, an attempt to account for these interactions explicitly by means of activity coefficients inserted as multipliers for the microscopic rate constants was unsuccessful. Re-examination of this approach in the context of a diffusion/evaporation model is suggested. The developed models have potential utility for dermal risk assessment and for prediction of aroma evolution following topical application of complex fragrances. Résumé Des données d'une étude publiée précédemment sur l'évaporation de parfum de humaine in vivo sont réanalysées en utilisant des modèles pharmacocinétiques compartimentés dont les constants microscopiques de taux sont des functions des propriétés physio-chimiques des composants de parfum. Selon l'analyse proposée, qui est limitée aux petites doses, l'absorption et l'évaporation de chaque composant sont des processus de premier ordre se produisant l'un de la peau (modèle d'un compartiment), ou l'autre de la peau et d'une couche de véhicule plus rapidement épuisée (modèles de deux compartiments). Les taux d'évaporation d'ingrédients d'un mélange de 12 composants contenant un fixatif de musc suivi par des décompositions exponentielles uniques qui ont été bien décrites par le modèle d'un compartiment. Un mélange sans fixatif mais identique pour le reste a rapporté des taux d'évaporation qui pourraient être caractérisés commes des décompositions bi-exponentielles avec une perte de deux compartiments. Ce résultat montre que les interactions d'ingrédient changent qualitativement et quantitativement les profils de taux d'évaporation des composants de parfum. Cependant, une tentative d'expliquer précisement ces interactions au moyen des coefficients d'activité insérés comme multiplicateurs pour les constants microscopiques de taux n'a pas été réussie. Le réexamen de cette approche dans le contexte d'un modèle de diffusion/evaporation est suggéré. Les modèles développés ont une utilité potentielle dans l'évaluation des risques cutané et pour la prévision de l'évolution d'arome suivant l'application topique des parfums complexes. [source] | ||||||||||||||||||||||||||||||||||||||||||||||