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Available Methods (available + methods)
Selected AbstractsFuzzy Monte Carlo Simulation and Risk Assessment in ConstructionCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 4 2010N. Sadeghi However, subjective and linguistically expressed information results in added non-probabilistic uncertainty in construction management. Fuzzy logic has been used successfully for representing such uncertainties in construction projects. In practice, an approach that can handle both random and fuzzy uncertainties in a risk assessment model is necessary. This article discusses the deficiencies of the available methods and proposes a Fuzzy Monte Carlo Simulation (FMCS) framework for risk analysis of construction projects. In this framework, we construct a fuzzy cumulative distribution function as a novel way to represent uncertainty. To verify the feasibility of the FMCS framework and demonstrate its main features, the authors have developed a special purpose simulation template for cost range estimating. This template is employed to estimate the cost of a highway overpass project. [source] Suppression of background gradients in (B0 gradient-based) NMR diffusion experimentsCONCEPTS IN MAGNETIC RESONANCE, Issue 5 2007Gang Zheng Abstract Artifacts arising from background gradients are very common in NMR diffusion (i.e., PGSE) experiments involving B0 gradients because of the unavoidable magnetic susceptibility differences and B0 inhomogeneity within and around the sample. This article presents the general methodology to develop PGSE sequences with background gradient suppression. Most of the available methods which can be used for the suppression of the effects of background gradients are discussed. And two newly developed methods are presented in detail: frequency analysis of spin-dephasing, which assumes the artifacts due to background gradients come from the resonance between the spin-dephasing caused by applied gradients and background gradients, and asymmetric bipolar stimulated-echo-based PGSE, which can suppress the effects of nonconstant background gradients. © 2007 Wiley Periodicals, Inc.Concepts Magn Reson Part A 30A: 261,277, 2007. [source] The changing world demography of type 2 diabetesDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 1 2003Anders Green Abstract In recent years it has been estimated that the current global prevalence of type 2 diabetes amounts to about 150 million patients. Projections suggest that by the year 2025 the number of prevalent patients in the world will reach approximately 300 million. It is assumed that the increase in the number of patients will be most pronounced in nations currently undergoing socio-economic development including increasing urbanization. The technique used to provide these estimates is based on results from available, contemporary survey results, combined with expected future trends in demographic indicators. We suggest that the currently available methods for the estimation of the future global burden of type 2 diabetes mellitus yield underestimates. Further modifications and validity tests of the modelling techniques are necessary in order to develop a reliable instrument to globally monitor the effects of the struggle against the diabetes problem. Copyright © 2002 John Wiley & Sons, Ltd. [source] The causes, consequences and detection of publication bias in psychiatryACTA PSYCHIATRICA SCANDINAVICA, Issue 4 2000Simon M. Gilbody Objective: Publication bias threatens the validity of published research, although this topic has received little attention in psychiatry. The purpose of this article is to produce a systematic overview of the causes and consequences of publication bias and to summarize the available methods with which it is detected and corrected. Method: Empirical evidence for the existence of publication bias is reviewed and the following methods are applied to an illustrative case example from psychiatry: funnel plot analysis; the ,file drawer method'; linear regression techniques; rank correlation; ,trim and fill'. Results: Small studies are particularly susceptible to publication and related bias. All methods to detect publication bias depend upon the availability of a number of individual studies with a range of sample sizes. Unfortunately, large numbers of studies of varying sample size are not always available in many areas of psychiatric research. Conclusion: Where possible researchers should always test for the presence of publication bias. The problem of publication bias will not be solved by anything other than a prospective trials register. [source] Combined treatment of achalasia , botulinum toxin injection followed by pneumatic dilatation: long-term resultsDISEASES OF THE ESOPHAGUS, Issue 2 2010R. Kroupa SUMMARY Injection of botulinum toxin (BT) and pneumatic dilatation are available methods in nonsurgical treatment of achalasia. Authors anticipate beneficial effect of prior BT injection on the success of pneumatic dilatation and duration of its effect. There are no long-term data available to assess efficacy of combined treatment. From 1998 to 2007, 51 consecutive patients (20 men and 31 women, age 24,83) with achalasia were included and prospectively followed up. Each patient received injection of 200 IU of BT into the lower esophageal sphincter (LES) during endoscopy and 8 days later pneumatic dilatation (PD) under X-ray control was performed. The follow-up was established every 3 months first year and then annually. The efficacy was evaluated by a questionnaire concerning patient's symptoms and manometry. Results were compared with 40 historical controls (16 men and 24 women, age 26,80) treated by PD alone using the same method and follow-up. Fifty-one patients underwent combined treatment. Four patients failed in follow-up and were not included for analysis. The mean duration of follow-up was 48 months with range 12,96 months. Thirty-four of forty-seven (72%) patients were satisfied with results with none or very rare and mild troubles at the time of the last visit. Forty-one patients were followed up more than 2 years. Effect of therapy lasted in 75% (31/41) of them. In 17 patients, more than 5 years after treatment, effect lasted in 12 (70%). Mean tonus of LES before therapy was 29 mm Hg (10,80), 3 months after therapy decreased to 14 mmHg (5,26). The cumulative 5 years remission rate (±95% CI) in combined treated patients 69% ± 8% was higher than in controls 50% ± 9%; however it, was not statistically significant (P= 0.07). In control group 1, case of perforation (2.5%) occurred. Eight patients (17%) with relapse of dysphagia were referred to laparoscopic Heller myotomy with no surgical complication. The main adverse effect was heartburn that appeared in 17 patients (36%). Initial injection of BT followed by PD seems to be effective for long-term results with fewer complications. But the combined therapy is not significantly superior to PD alone. [source] Documenting the heroin shortage in New South WalesDRUG AND ALCOHOL REVIEW, Issue 4 2006CAROLYN DAY Abstract Australian heroin markets have recently undergone dramatic change, sparking debate about the nature of such markets. This study aimed to determine the onset, peak and decline of the heroin shortage in New South Wales (NSW), using the most appropriate available methods to detect market level changes. The parameters of the heroin shortage were determined by reviewing: reports of heroin users about availability and price (derived from the existing literature and the Illicit Drug Reporting System); qualitative interviews with injecting drug users, and health and law enforcement professionals working in the illicit drug field; and examining data on heroin seizures over the past decade. There was a marked reduction in heroin supply in NSW in early 2001. An increase in the price of heroin occurred in 2001, whereas it had decreased steadily since 1996. A reduction in purity also occurred, as reported by drug users and heroin seizures. The peak period of the shortage appears to have been January to April 2001. The market appears to have stabilised since that time, although it has not returned to pre-2001 levels: heroin prices have decreased in NSW for street grams, but not to former levels, and the price of ,caps' (street deals) remain elevated. Heroin purity in NSW has remained low, with perhaps a 10% increase above the lowest recorded levels. These data support the notion that the heroin market in NSW underwent significant changes, which appear to have involved a lasting shift in the nature of the market. [source] Benchmark dose estimation based on epidemiologic cohort dataENVIRONMETRICS, Issue 5 2005Knashawn H. Morales Abstract Risk assessments based on epidemiologic studies are becoming increasingly common in evaluating environmental health risks and setting health standards. This article will discuss and compare some of the available methods for exposure,response modeling and risk estimation based on environmental epidemiologic studies with age-specific incidence and mortality data. Recommendations will be made regarding approaches that can be used in practice. Copyright © 2005 John Wiley & Sons, Ltd. [source] Quantitative Assessment of Seizure Severity for Clinical Trials: A Review of Approaches to Seizure ComponentsEPILEPSIA, Issue 1 2001Joyce A. Cramer Summary: Quantitative assessment of seizure severity has been approached using a variety of systems. This review describes currently available methods and possible new approaches to seizure assessment for clinical trials. A review of the literature on methods of seizure assessments resulted in tabulation of the seizure rating scales known as VA, Chalfont-National Hospital, Liverpool, Hague, and the Occupational Hazard Scale. Seizures have been evaluated by simply counting all events, counting events by type, by clinician ratings, patient ratings, and combinations. Each of the scales has advantages and disadvantages. Most scales share core components: seizure frequency, seizure type, seizure duration, postictal events, postictal duration, automatisms, seizure clusters, known patterns, warnings, tongue biting, incontinence, injuries, and functional impairment. This review revealed a partial consensus about aspects of seizures that are important markers for severity. However, usefulness of the existing scales is limited by lack of data on responsiveness. New approaches are needed to assess changes in seizure severity as a result of an intervention in a clinical trial. [source] Evaluations of maximization procedures for estimating linkage parameters under heterogeneityGENETIC EPIDEMIOLOGY, Issue 3 2004Swati Biswas Abstract Locus heterogeneity is a major problem plaguing the mapping of disease genes responsible for complex genetic traits via linkage analysis. A common feature of several available methods to account for heterogeneity is that they involve maximizing a multidimensional likelihood to obtain maximum likelihood estimates. The high dimensionality of the likelihood surface may be due to multiple heterogeneity (mixing) parameters, linkage parameters, and/or regression coefficients corresponding to multiple covariates. Here, we focus on this nontrivial computational aspect of incorporating heterogeneity by considering several likelihood maximization procedures, including the expectation maximization (EM) algorithm and the stochastic expectation maximization (SEM) algorithm. The wide applicability of these procedures is demonstrated first through a general formulation of accounting for heterogeneity, and then by applying them to two specific formulations. Furthermore, our simulation studies as well as an application to the Genetic Analysis Workshop 12 asthma datasets show that, among other observations, SEM performs better than EM. As an aside, we illustrate a limitation of the popular admixture approach for incorporating heterogeneity, proved elsewhere. We also show how to obtain standard errors (SEs) for EM and SEM estimates, using methods available in the literature. These SEs can then be combined with the corresponding estimates to provide confidence intervals of the parameters. © 2004 Wiley-Liss, Inc. [source] Rejection of periodic disturbances of unknown and time-varying frequencyINTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 2-3 2005Marc Bodson Abstract The paper reviews available methods for the rejection of periodic disturbances. Such disturbances are often encountered in active noise and vibration control, due to rotating machinery. The emphasis of the paper is on feedback control problems where reference sensors are not available. The case where the frequency of the disturbance is known is considered first. Two sets of algorithms are discussed: one based on the internal model principle of feedback control theory, and the second based on adaptive feedforward cancellation. An interesting observation is that algorithms originating from both approaches can be shown to be equivalent under certain conditions. When the frequency of the disturbance is unknown, an intuitive approach consists in combining a method for the rejection of disturbances of known frequency with a frequency estimator. Alternatively, one may seek to develop a stable adaptation mechanism so that the disturbance is cancelled asymptotically. While algorithms can be designed to adapt to plant and disturbance parameters, the most successful approaches use some limited plant information to adapt the magnitude, frequency, and phase parameters of the control signal. Applications are discussed throughout the paper. Copyright © 2004 John Wiley & Sons, Ltd. [source] Completed suicide among psychiatric in-patients with depression in an Australian mental hospitalINTERNATIONAL JOURNAL OF METHODS IN PSYCHIATRIC RESEARCH, Issue 1 2000Ajit Shah Abstract Up to 45% of completed psychiatric in-patient suicides have a diagnosis of depression. Twenty-two completed psychiatric in-patient suicides with depression, over a 21-year period, in a large psychiatric hospital in Melbourne, Australia, were examined. The characteristics, including demographic and clinical data, for the completed suicides with depression were compared with a comparison group of ,alive' in-patients with depression. Completed suicide among psychiatric in-patients with depression was associated with male sex, suicidal thoughts during admission, and fluctuating suicidal ideation or continuous absence of suicidal ideation. Over 40% of completed suicides occurred whilst on approved leave and over 20% after absconding from the hospital. Violent methods (including jumping in front of trains, trams and road traffic, jumping of buildings, hanging and drowning) were used in over 65% of completed suicides. Psychiatric units should be developed away from readily available methods of suicide. In-patients with suicidal thoughts during the admission and unstable suicidal ideation should be carefully observed to avoid absconding and suicide, and should be carefully assessed prior to granting of leave. Copyright © 2000 Whurr Publishers Ltd. [source] Administering local anaesthesia to paediatric dental patients , current status and prospects for the futureINTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 2 2002D. Ram Summary .,Fear-related behaviours have long been recognized as the most difficult aspect of patient management and can be a barrier to good care. Anxiety is one of the major issues in the dental treatment of children, and the injection is the most anxiety-provoking procedure for both children and adults. There is a constant search for ways to avoid the invasive, and often painful, nature of the injection, and to find more comfortable and pleasant means for anaesthesia before dental procedures. Objective. The purpose of the present review is to summarize relevant data on topics connected with the administration of local anaesthesia. Methods. The review will survey the current available methods, viz. electronic anaesthesia, lidocaine patch, computerized anaesthesia (the Wand), and the syrijet as well as the conventional injection, used for paediatric patients. Conclusions. Usually new techniques for locally anaesthetizing dental patients are tested on adults. However, despite recent research in the field, the injection remains the method of choice. It is necessary to continue to conduct studies using new techniques on adults and children, so that a more acceptable technique can be found. [source] The Enantioselective Addition of Alkyne Nucleophiles to Carbonyl GroupsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 7-8 2009Barry Abstract Over the past decade, large strides have been achieved in the invention of methods for the direct enantioselective addition of alkynes and metal alkynylide nucleophiles into prochiral aldehydes, ketones, and imines. This review highlights and compares the available methods for these transformations. [source] On-line monitoring of wastewater quality: a reviewJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 4 2001Wilfrid Bourgeois Abstract Real-time monitoring of wastewater quality remains an unresolved problem to the wastewater treatment industry. In order to comply with increasingly stringent environmental regulations, plant operators as well as instrument manufacturers have expressed the need for new standards and improved comparability and reliability of existing techniques. A review of currently available methods for monitoring global organic parameters (BOD, COD, TOC) is given. The study reviews both existing standard techniques and new innovative technologies with the focus on the sensors' potential for on-line and real-time monitoring and control. Current developments of biosensors, optical sensors and sensor arrays as well as virtual sensors for the monitoring of wastewater organic load are presented and the interests and limitations of these techniques with respect to their application to the wastewater monitoring are discussed. © 2001 Society of Chemical Industry [source] On searching in, sampling of, and dynamically moving through conformational space of biomolecular systems: A reviewJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 2 2008Markus Christen Abstract Methods to search for low-energy conformations, to generate a Boltzmann-weighted ensemble of configurations, or to generate classical-dynamical trajectories for molecular systems in the condensed liquid phase are briefly reviewed with an eye to application to biomolecular systems. After having chosen the degrees of freedom and method to generate molecular configurations, the efficiency of the search or sampling can be enhanced in various ways: (i) efficient calculation of the energy function and forces, (ii) application of a plethora of search enhancement techniques, (iii) use of a biasing potential energy term, and (iv) guiding the sampling using a reaction or transition pathway. The overview of the available methods should help the reader to choose the combination that is most suitable for the biomolecular system, degrees of freedom, interaction function, and molecular or thermodynamic properties of interest. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008 [source] Molecular dynamics simulation in the grand canonical ensembleJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 10 2007Hossein Eslami Abstract An extended system Hamiltonian is proposed to perform molecular dynamics (MD) simulation in the grand canonical ensemble. The Hamiltonian is similar to the one proposed by Lynch and Pettitt (Lynch and Pettitt, J Chem Phys 1997, 107, 8594), which consists of the kinetic and potential energies for real and fractional particles as well as the kinetic and potential energy terms for material and heat reservoirs interacting with the system. We perform a nonlinear scaling of the potential energy parameters of the fractional particle, as well as its mass to vary the number of particles dynamically. On the basis of the equations of motion derived from this Hamiltonian, an algorithm has been proposed for MD simulation at constant chemical potential. The algorithm has been tested for the ideal gas, for the Lennard,Jones fluid over a wide range of temperatures and densities, and for water. The results for the low-density Lennard,Jones fluid are compared with the predictions from a truncated virial equation of state. In the case of the dense Lennard,Jones fluid and water our predicted results are compared with the results reported using other available methods for the calculation of the chemical potential. The method is also applied to the case of vapor-liquid coexistence point predictions. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007 [source] Automatic appearance-based loop detection from three-dimensional laser data using the normal distributions transformJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 11-12 2009Martin Magnusson We propose a new approach to appearance-based loop detection for mobile robots, using three-dimensional (3D) laser scans. Loop detection is an important problem in the simultaneous localization and mapping (SLAM) domain, and, because it can be seen as the problem of recognizing previously visited places, it is an example of the data association problem. Without a flat-floor assumption, two-dimensional laser-based approaches are bound to fail in many cases. Two of the problems with 3D approaches that we address in this paper are how to handle the greatly increased amount of data and how to efficiently obtain invariance to 3D rotations. We present a compact representation of 3D point clouds that is still discriminative enough to detect loop closures without false positives (i.e., detecting loop closure where there is none). A low false-positive rate is very important because wrong data association could have disastrous consequences in a SLAM algorithm. Our approach uses only the appearance of 3D point clouds to detect loops and requires no pose information. We exploit the normal distributions transform surface representation to create feature histograms based on surface orientation and smoothness. The surface shape histograms compress the input data by two to three orders of magnitude. Because of the high compression rate, the histograms can be matched efficiently to compare the appearance of two scans. Rotation invariance is achieved by aligning scans with respect to dominant surface orientations. We also propose to use expectation maximization to fit a gamma mixture model to the output similarity measures in order to automatically determine the threshold that separates scans at loop closures from nonoverlapping ones. We discuss the problem of determining ground truth in the context of loop detection and the difficulties in comparing the results of the few available methods based on range information. Furthermore, we present quantitative performance evaluations using three real-world data sets, one of which is highly self-similar, showing that the proposed method achieves high recall rates (percentage of correctly identified loop closures) at low false-positive rates in environments with different characteristics. © 2009 Wiley Periodicals, Inc. [source] Accuracy, precision and quality control in age determination, including a review of the use and abuse of age validation methodsJOURNAL OF FISH BIOLOGY, Issue 2 2001S. E. Campana Many calcified structures produce periodic growth increments useful for age determination at the annual or daily scale. However, age determination is invariably accompanied by various sources of error, some of which can have a serious effect on age-structured calculations. This review highlights the best available methods for insuring ageing accuracy and quantifying ageing precision, whether in support of large-scale production ageing or a small-scale research project. Included in this review is a critical overview of methods used to initiate and pursue an accurate and controlled ageing program, including (but not limited to) validation of an ageing method. The distinction between validation of absolute age and increment periodicity is emphasized, as is the importance of determining the age of first increment formation. Based on an analysis of 372 papers reporting age validation since 1983, considerable progress has been made in age validation efforts in recent years. Nevertheless, several of the age validation methods which have been used routinely are of dubious value, particularly marginal increment analysis. The two major measures of precision, average percent error and coefficient of variation, are shown to be functionally equivalent, and a conversion factor relating the two is presented. Through use of quality control monitoring, ageing errors are readily detected and quantified; reference collections are the key to both quality control and reduction of costs. Although some level of random ageing error is unavoidable, such error can often be corrected after the fact using statistical (,digital sharpening)' methods. [source] Isotropic Component Trace AnalysisJOURNAL OF NEUROIMAGING, Issue 3 2005Hitoshi Matsuzawa MD ABSTRACT A new method for analyzing diffusion tensor imaging (DTI) of the brain, based on a recently introduced algorithm, lambda chart analysis (LCA), is presented. Pretreatment of a given DTI data set with LCA, which effectively segregates isotropic and aniso tropic components, allows for total removal of the anisotropic component from the DTI data set. The remaining pure isotropic component can therefore be subjected to further analysis simi lar to that applied in the trace histogram method. Deconvolution of the trace function yielded 3 Gaussian elements. Remapping of these 3 deconvoluted isotropic elements back onto the 2-dimensional image plane provided anatomical correlates of each element. The algorithm, referred to here as isotropic com ponent trace analysis, can be used as a pictorial analytic tool, as well as a numerical analytical tool, for the noninvasive assess ment of isotropic parenchymal components. The presented method provides quantitative indices of certain parenchymal parameters with better clarity than currently available methods. A ready-to-use program, EZ-LCA, for this powerful method is provided (available at http://coe.bri.niigata-u.ac.jp). [source] Simultaneous Raman micro,spectroscopy of optically trapped and stacked cellsJOURNAL OF RAMAN SPECTROSCOPY, Issue 9 2007P. R. T. Jess Abstract The combination of Raman spectroscopy and optical trapping holds great promise for single-cell studies and is an emergent theme in microfluidic environments. Here, the evolution of the Raman signal intensity with an axial increment of the mass of the substance of interest inside a specific Raman excitation volume is investigated. Whilst Raman spectroscopy may be applied to tissue samples, solutions and single cells, there are no easily available methods to rapidly acquire signals from small cell populations. We show a simple but powerful method to record the Raman intensity signal simultaneously from a small number of trapped cells or colloidal particles using the technique of optical stacking. The Raman spectra of stacks of red blood cells and yeast cells show that this method can be applied to biological systems. We demonstrate how we may reveal biochemical fingerprints that would otherwise require long integration times for each single cell or averaging over many sequentially acquired cell spectra. There is potential to apply this method to directly attain Raman spectra from sorted sub-populations of normal, abnormal and tumour cell lines. Copyright © 2007 John Wiley & Sons, Ltd. [source] Evaluation and optimisation of five different extraction methods for soy DNA in chocolate and biscuits.JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2004Extraction of DNA as a first step in GMO analysis Abstract A method is described to discriminate between genetically modified (GM) and non-modified foodstuffs by detecting the presence of newly introduced genes at the protein or DNA level. Currently available methods operate almost exclusively at the DNA level and are based on the polymerase chain reaction (PCR). The first and most crucial step in this process is the isolation of DNA. In this study, five different methods for the isolation of DNA from chocolate and biscuits were evaluated, using four commercially available extraction kits and a non-commercial method for amplification of the soybean-specific lectin gene. The latter method involves the use of hot-start Taq polymerase, to prevent the formation of non-specific amplification products, and an increase in the number of cycles from 35 to 41. The performance of the non-commercial cetyl trimethylammonium bromide (CTAB)-based method was the best, taking into consideration the adaptations of the extraction procedure, although this method was more time-consuming than the others. Chocolate (white, milk and dark) and several biscuits generated positive amplification results using this PCR approach. Copyright © 2004 Society of Chemical Industry [source] Monitoring adherence to beclomethasone in asthmatic children and adolescents through four different methodsALLERGY, Issue 10 2009N. S. Jentzsch Background:, Suboptimal adherence to inhaled steroids is a known problem in children and adolescents, even when medications are administered under parental supervision. This study aimed to verify the adherence rate to beclomethasone dipropionate (BDP) by four currently available methods. Methods:, In this concurrent cohort study, 102 randomly selected asthmatic children and adolescents aged 3,14 years were followed for 12 months. Adherence rate was assessed every 2 months by self and/or parent report, pharmacy dispensing data, electronic device (Doser®; Meditrack Products, Hudson, MA, USA) monitor, and canister weight. Results:, Mean adherence rates to BDP by self and/or parent report, pharmacy records, Doser, and canister weight were 97.9% (95% CI 88.0,98.6), 70.0% (95% CI 67.6,72.4), 51.5% (95% CI 48.3,54.6), and 46.3% (95% CI 44.1,48.4), respectively. Agreement analysis between (Doser) and canister weight revealed a weighted kappa equal to 0.76 (95% CI 0.65,0.87). Conclusions:, Adherence was a dynamic event and rates decreased progressively for all methods over the 12-month follow-up. Canister weight and electronic monitoring measures were more accurate than self/parent reports and pharmacy records. Rates obtained by these two methods were very close and statistical analysis also showed a substantial agreement between them. As measurements by canister weight are less costly compared with currently available electronic devices, it should be considered as an alternative method to assess adherence in both clinical research and practice. [source] In vitro susceptibility-testing in Aspergillus speciesMYCOSES, Issue 5 2008Cornelia Lass-Flörl Summary Aspergillus species are the most common causes of invasive mould infections in immunocompromised patients. The introduction of new antifungal agents and recent reports of resistance emerging during treatment of Aspergillus infections have highlighted the need for in vitro susceptibility-testing. Various testing procedures have been proposed, including macrodilution and microdilution, agar diffusion, disc diffusion and Etest. At present, one of the most widely used assays is the M38-A reference method for filamentous fungi, published by the Clinical Laboratory Standard Institute and the Etest. Recently, the European Committee on Antimicrobial Susceptibility-testing (EUCAST) has charged its Antifungal Susceptibility-testing Subcommittee (AFST-EUCAST) with the preparation of new guidelines for in vitro susceptibility-testing of antifungals against Aspergillus spp. (EUCAST-AFST-ASPERGILLUS) defining breakpoints. This paper reviews the available methods for antifungal susceptibility-testing in Aspergillus spp. as well as the scant data regarding the clinical implications of in vitro testing. [source] Measurement of exhaled nitric oxide in young children during tidal breathing through a facemaskPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 3 2005Peter Fleng Daniel Measurement of exhaled nitric oxide (eNO) offers a non-invasive means for assessment of airway inflammation. The currently available methods are difficult to apply in preschool children. We evaluated four methods potentially applicable for eNO measurement during tidal breathing in young children. eNO was assessed during tidal breathing in 24 children, 2,7 yr old, using a facemask which separated nasal and oral airflow. Facemasks with and without a one-way valve allowing exhalation through the nose were used. Expiratory flow control was not attempted. Measurements of eNO were performed both on-line and off-line. In 11 children, 8,12 yr old, measurements were compared with the standard single breath on-line method. eNO was significantly lower applying the one-way valve in on-line and off-line measurements in comparison with measurements without the valve [4.6 and 3.9 parts per billion (ppb) vs. 6.9 ppb and 6.5 ppb]. The mean within subject coefficient of variation (CV) was significantly lower in on-line measurements with the one-way valve (9.6%) compared with the other three methods (18.8, 27.7 and 29.3% respectively). Measurements with a facemask fitted with a one-way valve yielded similar eNO levels as the standard single breath method (7.0 ppb vs. 6.9 ppb) and reproducibility (9.8% vs. 7.1%). In conclusion, reproducible measurements of eNO can be obtained without control of expiration flow using a facemask fitted with a one-way valve on the nasal compartment. The likely explanation to this is that the one-way valve reduces the admixture of nasal NO, thereby improving the reliability of eNO measurements. [source] Is tile drainage water representative of root zone leaching of pesticides?PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 5 2007Ole H Jacobsen Abstract Given the methods presently available, determination of flux-averaged concentrations of pesticides in structured soils is always a compromise. Most of the available methods entail major uncertainties and limitations. Tile drainage monitoring has several advantages, but the extent to which it is representative of overall leaching has been questioned because it comprises a mixture of water of different origins. This literature review evaluates whether drainage water pesticide concentrations are representative of root zone leaching of pesticides. As there are no reports quantifying the extent to which the flux-averaged concentration of pesticides in drainage water differs from that found between the drains, evidence-based conclusions cannot be drawn. Nevertheless, the existing literature does suggest that the concentration in drainage water does not always correspond to the concentration at drain depth between the drains; depending on the conditions pertaining, the concentrations may be higher or lower. As to whether the flux-averaged concentration of pesticides in drainage water is representative of the interdrain concentration at drain depth it is concluded that (1) the representativeness of drainage water concentrations can be questioned on very well-drained soils and on poorly drained soils with little capacity for lateral transport beneath the plough layer, (2) the conditions provided by relatively porous soils and moderate climatic conditions are conducive to the drainage water concentration being representative and (3) drainage water will be more representative in the case of weakly sorbed pesticides than for strongly sorbed pesticides. Used critically, it is thus believed that drainage water concentrations can serve to characterize the flux-averaged concentration of pesticides at drain depth. However, the use of drainage water for determining average concentrations necessitates thorough investigation and interpretation of precipitation, percolation, drain outflow and concentration dynamics. Copyright © 2007 Society of Chemical Industry [source] Sunscreen protection in the ultraviolet A region: how to measure the effectivenessPHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 1 2001C. Cole Products containing ultraviolet (UV) radiation absorbing or scattering ingredients provide varying degrees of protection from sunlight (or other UV sources), thus minimizing the deleterious effects on the skin. The "sun protection factor" (SPF) of sunscreen products has become a well recognized indicator of protection against sunburn induced predominantly by ultraviolet B radiation (UVB: 290,320 nm). A similar system of denoting sunscreen protection from ultraviolet A (UVA: 320,400 nm) radiation has not been universally recognized. A variety of test methods have been proposed, both in vitro and in vivo, each with specific virtues and shortcomings. Regulatory agencies and industry have been reviewing the available methods over the past decade in an effort to develop consumer meaningful claims and appropriate substantiation methods. This article reviews these test methodologies, in vitro and in vivo, as well as the biological background that establishes the need for UVA protection, and the UVA content of solar radiation and its variability. [source] Application of immunoproteomics to leptospirosis: towards clinical diagnostics and vaccine discoveryPROTEOMICS - CLINICAL APPLICATIONS, Issue 4 2007Uraiwan Kositanont Abstract Each of the currently available methods for serodiagnosis of leptospirosis, including the microscopic agglutination test (MAT), has its own drawback(s) when used in clinical practice. A new diagnostic test is therefore required for an earlier and more accurate diagnosis of leptospirosis. We applied immunoproteomics to define potential immunogens from five serovars of Leptospira reference strains. A leptospiral whole cell lysate from each serovar was used as the antigen to react with IgG and IgM in the sera from four patients with a positive MAT. Sera from four non-leptospirosis patients with a negative MAT were pooled and used as the negative control. 2-D Western blot analysis showed that the degree of immunoreactivity corresponded with the MAT titers. No immunoreactive spots were detected when the pooled control sera were used. A total of 24 protein spots immunoreacted with IgM and/or IgG from patients with leptospirosis. These immunoreactive proteins were identified by MALDI-TOF MS and were classified into five groups, including flagellar proteins, chaperones/heat shock proteins, transport proteins, metabolic enzymes, and hypothetical proteins. More immunoreactive spots were detected with anti-human IgG in the sera of all patients and with all the serovars of leptospires used. Some of the identified proteins immunoreacted only with IgG, whereas the others were detectable with both IgM and IgG. Among the immunoreactive proteins identified, FlaB proteins (flagellin and flagellar core protein) have been shown to have a potential role in clinical diagnostics and vaccine development. These data underscore the significant impact of immunoproteomics in clinical applications. [source] The determination of N- nitrosamines in foodQUALITY ASSURANCE & SAFETY OF CROPS & FOOD, Issue 1 2010Colin Crews Abstract Introduction N -nitrosamines are formed in food as a result of natural chemical interactions, but mainly through food processing activity. Most are potent carcinogens and their determination is therefore of considerable importance. They exist in various chemical forms and have been measured by colorimetric and spectroscopic methods following gas or liquid chromatography or as a total N -nitroso group by measurement of chemically released nitric oxide. Objectives To provide an overview of the available methods for the analysis of N -nitrosamines in food that includes recently developments. Methods The literature was reviewed from the discovery of the N -nitrosamine problem and the introduction on the N -nitroso-specific detector. Results The evaluation shows that analytical detection methods for volatile N -nitrosamines in food have changed little since the introduction on the N -nitroso-specific detector and that research into the occurrence and formation of both non-volatile N -nitrosamines and the apparent total N -nitroso content (ATNC) have declined. Methods for measuring the apparent total N -nitroso content have not been improved significantly in recent years. Conclusion Modern sample extraction techniques and mass spectrometric methods for the volatile N -nitrosamines have been applied more extensively to water analysis and offer a good opportunity to improve the determination of these carcinogens in food and make the analysis more widely available. Developments in liquid chromatography-mass spectrometry should provide an avenue for renewed interest in non-volatile N -nitrosamines, and could help with the identification of novel compounds whose presence is suggested by the high apparent total N -nitroso content of some foods. [source] Estimation of genetic variability of the founder population in a conservation scheme using microsatellitesANIMAL GENETICS, Issue 3 2003M. A. Toro Summary In a conservation programme with genealogical records it is possible to estimate the amount of variability of the founder population from a measure of the similarity among the individuals in the current population based on microsatellite markers. Here we compare three available methods and we shown that the one based on the molecular coancestry coefficient should be preferred. [source] Assessment of JC virus DNA in blood and urine from natalizumab-treated patientsANNALS OF NEUROLOGY, Issue 3 2010Richard A. Rudick MD Objective Analyses were conducted to determine the clinical utility of measuring JC virus (JCV) DNA in blood or urine of natalizumab-treated multiple sclerosis (MS) patients to predict the risk of progressive multifocal leukoencephalopathy (PML). Methods A total of 12,850 blood and urine samples from nearly 1,400 patients participating in natalizumab clinical trials were tested for JCV DNA using a commercially available quantitative polymerase chain reaction (qPCR) assay. A subset of these samples was also tested using a more sensitive qPCR assay developed at the National Institutes of Health (NIH). Results At the time natalizumab dosing was suspended, JCV DNA was detected in plasma by the commercial assay in 4 of 1,397 (0.3%) patients; the NIH assay confirmed these positive samples and detected JCV DNA in an additional 2 of 205 (1%) patients who tested negative with the commercial assay. None of these 6 JCV DNA positive patients developed PML. In a 48-week study testing the safety of natalizumab redosing, JCV DNA was detected in plasma of 6 of 1,094 (0.3%) patients, none of whom developed PML. Urine at baseline and week 48 was assessed in 224 patients; 58 (26%) were positive at baseline, and 55 (25%) were positive after 48 weeks of natalizumab, treatment. JCV DNA was not detected in peripheral blood mononuclear cells from any of these 1,094 patients before or after natalizumab treatment. In 5 patients who developed PML, JCV DNA was not detected in blood at any time point before symptoms first occurred. Interpretation Measuring JCV DNA in blood or urine with currently available methods is unlikely to be useful for predicting PML risk in natalizumab-treated MS patients. Ann Neurol 2010 [source] | |||||||||||||||||||||||||||||||||||||||||||