Surveillance and laboratory detection for non-polio enteroviruses in the European Union/European Economic Area, 2016

PubMed Central

Harvala, Heli; Jasir, Aftab; Penttinen, Pasi; Pastore Celentano, Lucia; Greco, Donato; Broberg, Eeva

2017-01-01

Enteroviruses (EVs) cause severe outbreaks of respiratory and neurological disease as illustrated by EV-D68 and EV-A71 outbreaks, respectively. We have mapped European laboratory capacity for identification and characterisation of non-polio EVs to improve preparedness to respond to (re)-emerging EVs linked to severe disease. An online questionnaire on non-polio EV surveillance and laboratory detection was submitted to all 30 European Union (EU)/European Economic Area (EEA) countries. Twenty-nine countries responded; 26 conducted laboratory-based non-polio EV surveillance, and 24 included neurological infections in their surveillance. Eleven countries have established specific surveillance for EV-D68 via sentinel influenza surveillance (n = 7), typing EV-positive respiratory samples (n = 10) and/or acute flaccid paralysis surveillance (n = 5). Of 26 countries performing non-polio EV characterisation/typing, 10 further characterised culture-positive EV isolates, whereas the remainder typed PCR-positive but culture-negative samples. Although 19 countries have introduced sequence-based EV typing, seven still rely entirely on virus isolation. Based on 2015 data, six countries typed over 300 specimens mostly by sequencing, whereas 11 countries characterised under 50 EV-positive samples. EV surveillance activity varied between EU/EEA countries, and did not always specifically target patients with neurological and/or respiratory infections. Introduction of sequence-based typing methods is needed throughout the EU/EEA to enhance laboratory capacity for the detection of EVs. PMID:29162204

Surveillance and laboratory detection for non-polio enteroviruses in the European Union/European Economic Area, 2016.

PubMed

Harvala, Heli; Jasir, Aftab; Penttinen, Pasi; Pastore Celentano, Lucia; Greco, Donato; Broberg, Eeva

2017-11-01

Enteroviruses (EVs) cause severe outbreaks of respiratory and neurological disease as illustrated by EV-D68 and EV-A71 outbreaks, respectively. We have mapped European laboratory capacity for identification and characterisation of non-polio EVs to improve preparedness to respond to (re)-emerging EVs linked to severe disease. An online questionnaire on non-polio EV surveillance and laboratory detection was submitted to all 30 European Union (EU)/European Economic Area (EEA) countries. Twenty-nine countries responded; 26 conducted laboratory-based non-polio EV surveillance, and 24 included neurological infections in their surveillance. Eleven countries have established specific surveillance for EV-D68 via sentinel influenza surveillance (n = 7), typing EV-positive respiratory samples (n = 10) and/or acute flaccid paralysis surveillance (n = 5). Of 26 countries performing non-polio EV characterisation/typing, 10 further characterised culture-positive EV isolates, whereas the remainder typed PCR-positive but culture-negative samples. Although 19 countries have introduced sequence-based EV typing, seven still rely entirely on virus isolation. Based on 2015 data, six countries typed over 300 specimens mostly by sequencing, whereas 11 countries characterised under 50 EV-positive samples. EV surveillance activity varied between EU/EEA countries, and did not always specifically target patients with neurological and/or respiratory infections. Introduction of sequence-based typing methods is needed throughout the EU/EEA to enhance laboratory capacity for the detection of EVs.

Optimising a modified free-space permittivity characterisation method for civil engineering applications

NASA Astrophysics Data System (ADS)

Muller, Wayne; Scheuermann, Alexander

2016-04-01

Measuring the electrical permittivity of civil engineering materials is important for a range of ground penetrating radar (GPR) and pavement moisture measurement applications. Compacted unbound granular (UBG) pavement materials present a number of preparation and measurement challenges using conventional characterisation techniques. As an alternative to these methods, a modified free-space (MFS) characterisation approach has previously been investigated. This paper describes recent work to optimise and validate the MFS technique. The research included finite difference time domain (FDTD) modelling to better understand the nature of wave propagation within material samples and the test apparatus. This research led to improvements in the test approach and optimisation of sample sizes. The influence of antenna spacing and sample thickness on the permittivity results was investigated by a series of experiments separating antennas and measuring samples of nylon and water. Permittivity measurements of samples of nylon and water approximately 100 mm and 170 mm thick were also compared, showing consistent results. These measurements also agreed well with surface probe measurements of the nylon sample and literature values for water. The results indicate permittivity estimates of acceptable accuracy can be obtained using the proposed approach, apparatus and sample sizes.

Teaching method validation in the clinical laboratory science curriculum.

PubMed

Moon, Tara C; Legrys, Vicky A

2008-01-01

With the Clinical Laboratory Improvement Amendment's (CLIA) final rule, the ability of the Clinical Laboratory Scientist (CLS) to perform method validation has become increasingly important. Knowledge of the statistical methods and procedures used in method validation is imperative for clinical laboratory scientists. However, incorporating these concepts in a CLS curriculum can be challenging, especially at a time of limited resources. This paper provides an outline of one approach to addressing these topics in lecture courses and integrating them in the student laboratory and the clinical practicum for direct application.

Image analysis for material characterisation

NASA Astrophysics Data System (ADS)

Livens, Stefan

In this thesis, a number of image analysis methods are presented as solutions to two applications concerning the characterisation of materials. Firstly, we deal with the characterisation of corrosion images, which is handled using a multiscale texture analysis method based on wavelets. We propose a feature transformation that deals with the problem of rotation invariance. Classification is performed with a Learning Vector Quantisation neural network and with combination of outputs. In an experiment, 86,2% of the images showing either pit formation or cracking, are correctly classified. Secondly, we develop an automatic system for the characterisation of silver halide microcrystals. These are flat crystals with a triangular or hexagonal base and a thickness in the 100 to 200 nm range. A light microscope is used to image them. A novel segmentation method is proposed, which allows to separate agglomerated crystals. For the measurement of shape, the ratio between the largest and the smallest radius yields the best results. The thickness measurement is based on the interference colours that appear for light reflected at the crystals. The mean colour of different thickness populations is determined, from which a calibration curve is derived. With this, the thickness of new populations can be determined accurately.

Characterising invasive non-native Rhododendron ponticum spectra signatures with spectroradiometry in the laboratory and field: Potential for remote mapping

NASA Astrophysics Data System (ADS)

Taylor, Sarah L.; Hill, Ross A.; Edwards, Colin

2013-07-01

Compared with traditional ground surveys, remote sensing has the potential to map the spatial extent of non-native invasive species rapidly and reliably. This paper assesses the potential of spectroradiometry to distinguish and characterise the status of invasive non-native rhododendron (Rhododendron ponticum). Absolute reflectance of target plant material was measured with an ASD Fieldspec Pro System under standardised laboratory conditions and in the field to characterise spectral signatures in the winter, during leaf-off conditions for woodland overstory, and in the summer when mature rhododendrons are flowering. A logistic regression model of absolute reflectance at key wavelengths (490, 550, 610, 1040 and 1490 nm) was used to determine the success of discriminating rhododendron from three other shrubby species likely to be encountered in woodlands during the winter. The logistic regression model was highly significant (p < 0.001), with 93.5% of 246 leaf sets correctly identified as rhododendron or non-rhododendron (i.e. cherry laurel (Prunus laurocerasus), holly (Ilex aquifolium), and beech (Fagus sylvatica)). Rescaling the data to emulate the spectral resolution of airborne and satellite acquired data decreased the total success rate of correctly identifying rhododendron by only 0.4%; although this error rate will likely increase for airborne or satellite data as a result of atmospheric attenuation and reduced spatial resolution. This demonstrates the potential to map bush presence using hyperspectral data and indicates the optimum spectral wavelengths required. Such information is critical to the development of successful strategic management plans to eradicate rhododendron (and the associated Phytophthora ramorum pathogen) effectively from a site.

Implications for current regulatory waste toxicity characterisation methods from analysing metal and metalloid leaching from photovoltaic modules

NASA Astrophysics Data System (ADS)

Collins, Mary Kayla; Anctil, Annick

2017-07-01

The appropriateness of regulatory methods to characterise the toxicity of photovoltaic (PV) modules was investigated to quantify potential environmental impacts for modules disposed of in landfills. Because solar energy is perceived as a green technology, it is important to ensure that end-of-life issues will not be detrimental to solar energy's success. United States Environmental Protection Agency Method 1311, California waste extraction test, and modified versions of both were performed on a multi-crystalline silicon module and cells and a copper indium gallium diselenide (CIGS) module. Variations in metal leachate concentrations were found with changes in testing parameters. Lead concentrations from the multi-crystalline module ranged from 16.2 to 50.2 mg/L. Cadmium concentrations from the CIGS module ranged from 0.1 to 3.52 mg/L. This raises doubt that regulatory methods can adequately characterise PV modules. The results are useful for developing end-of-life procedures, which is a positive step towards avoiding an e-waste problem and continuing trends of increasing installation and cost reduction in the PV market.

Comparability of river suspended-sediment sampling and laboratory analysis methods

USGS Publications Warehouse

Groten, Joel T.; Johnson, Gregory D.

2018-03-06

Accurate measurements of suspended sediment, a leading water-quality impairment in many Minnesota rivers, are important for managing and protecting water resources; however, water-quality standards for suspended sediment in Minnesota are based on grab field sampling and total suspended solids (TSS) laboratory analysis methods that have underrepresented concentrations of suspended sediment in rivers compared to U.S. Geological Survey equal-width-increment or equal-discharge-increment (EWDI) field sampling and suspended sediment concentration (SSC) laboratory analysis methods. Because of this underrepresentation, the U.S. Geological Survey, in collaboration with the Minnesota Pollution Control Agency, collected concurrent grab and EWDI samples at eight sites to compare results obtained using different combinations of field sampling and laboratory analysis methods.Study results determined that grab field sampling and TSS laboratory analysis results were biased substantially low compared to EWDI sampling and SSC laboratory analysis results, respectively. Differences in both field sampling and laboratory analysis methods caused grab and TSS methods to be biased substantially low. The difference in laboratory analysis methods was slightly greater than field sampling methods.Sand-sized particles had a strong effect on the comparability of the field sampling and laboratory analysis methods. These results indicated that grab field sampling and TSS laboratory analysis methods fail to capture most of the sand being transported by the stream. The results indicate there is less of a difference among samples collected with grab field sampling and analyzed for TSS and concentration of fines in SSC. Even though differences are present, the presence of strong correlations between SSC and TSS concentrations provides the opportunity to develop site specific relations to address transport processes not captured by grab field sampling and TSS laboratory analysis methods.

[Bacterial identification methods in the microbiology laboratory].

PubMed

Bou, Germán; Fernández-Olmos, Ana; García, Celia; Sáez-Nieto, Juan Antonio; Valdezate, Sylvia

2011-10-01

In order to identify the agent responsible of the infectious process and understanding the pathogenic/pathological implications, clinical course, and to implement an effective antimicrobial therapy, a mainstay in the practice of clinical microbiology is the allocation of species to a microbial isolation. In daily routine practice microbiology laboratory phenotypic techniques are applied to achieve this goal. However, they have some limitations that are seen more clearly for some kinds of microorganism. Molecular methods can circumvent some of these limitations, although its implementation is not universal. This is due to higher costs and the level of expertise required for thei implementation, so molecular methods are often centralized in reference laboratories and centers. Recently, proteomics-based methods made an important breakthrough in the field of diagnostic microbiology and will undoubtedly have a major impact on the future organization of the microbiology services. This paper is a short review of the most noteworthy aspects of the three bacterial identification methods described above used in microbiology laboratories. Copyright © 2011 Elsevier España, S.L. All rights reserved.

Implementation of 5S Method for Ergonomic Laboratory

NASA Astrophysics Data System (ADS)

Dila Sari, Amarria; Ilma Rahmillah, Fety; Prabowo Aji, Bagus

2017-06-01

This article discusses 5S implementation in Work System Design and Ergonomic Laboratory, Department of Industrial Engineering, Islamic University of Indonesia. There are some problems related to equipment settings for activity involving students such as files which is accumulated over the previous year practicum, as well as the movement of waste in the form of time due to the placement of goods that do not fit. Therefore, this study aims to apply the 5S method in DSK & E laboratory to facilitate the work processes and reduce waste. The project is performed by laboratory management using 5S methods in response to continuous improvement (Kaizen). Moreover, some strategy and suggestions are promoted to impose 5S system within the laboratory. As a result, the tidiness and cleanliness can be achieved that lead to the great performance of laboratory users. Score assessment before implementing 5S DSKE laboratory is at 64 (2.56) while the score after implementation is 32 (1.28) and shows an improvement of 50%. This has implications for better use in the laboratory area, save time when looking for tools and materials due to its location and good visual control, as well as improving the culture and spirit of ‘5S’ on staff regarding better working environment

Standardization of Laboratory Methods for the PERCH Study

PubMed Central

Karron, Ruth A.; Morpeth, Susan C.; Bhat, Niranjan; Levine, Orin S.; Baggett, Henry C.; Brooks, W. Abdullah; Feikin, Daniel R.; Hammitt, Laura L.; Howie, Stephen R. C.; Knoll, Maria Deloria; Kotloff, Karen L.; Madhi, Shabir A.; Scott, J. Anthony G.; Thea, Donald M.; Adrian, Peter V.; Ahmed, Dilruba; Alam, Muntasir; Anderson, Trevor P.; Antonio, Martin; Baillie, Vicky L.; Dione, Michel; Endtz, Hubert P.; Gitahi, Caroline; Karani, Angela; Kwenda, Geoffrey; Maiga, Abdoul Aziz; McClellan, Jessica; Mitchell, Joanne L.; Morailane, Palesa; Mugo, Daisy; Mwaba, John; Mwansa, James; Mwarumba, Salim; Nyongesa, Sammy; Panchalingam, Sandra; Rahman, Mustafizur; Sawatwong, Pongpun; Tamboura, Boubou; Toure, Aliou; Whistler, Toni; O’Brien, Katherine L.; Murdoch, David R.

2017-01-01

Abstract The Pneumonia Etiology Research for Child Health study was conducted across 7 diverse research sites and relied on standardized clinical and laboratory methods for the accurate and meaningful interpretation of pneumonia etiology data. Blood, respiratory specimens, and urine were collected from children aged 1–59 months hospitalized with severe or very severe pneumonia and community controls of the same age without severe pneumonia and were tested with an extensive array of laboratory diagnostic tests. A standardized testing algorithm and standard operating procedures were applied across all study sites. Site laboratories received uniform training, equipment, and reagents for core testing methods. Standardization was further assured by routine teleconferences, in-person meetings, site monitoring visits, and internal and external quality assurance testing. Targeted confirmatory testing and testing by specialized assays were done at a central reference laboratory. PMID:28575358

Characterisation of nanomaterial hydrophobicity using engineered surfaces

NASA Astrophysics Data System (ADS)

Desmet, Cloé; Valsesia, Andrea; Oddo, Arianna; Ceccone, Giacomo; Spampinato, Valentina; Rossi, François; Colpo, Pascal

2017-03-01

Characterisation of engineered nanomaterials (NMs) is of outmost importance for the assessment of the potential risks arising from their extensive use. NMs display indeed a large variety of physico-chemical properties that drastically affect their interaction with biological systems. Among them, hydrophobicity is an important property that is nevertheless only slightly covered by the current physico-chemical characterisation techniques. In this work, we developed a method for the direct characterisation of NM hydrophobicity. The determination of the nanomaterial hydrophobic character is carried out by the direct measurement of the affinity of the NMs for different collectors. Each collector is an engineered surface designed in order to present specific surface charge and hydrophobicity degrees. Being thus characterised by a combination of surface energy components, the collectors enable the NM immobilisation with surface coverage in relation to their hydrophobicity. The experimental results are explained by using the extended DLVO theory, which takes into account the hydrophobic forces acting between NMs and collectors.

Intra-laboratory validation of chronic bee paralysis virus quantitation using an accredited standardised real-time quantitative RT-PCR method.

PubMed

Blanchard, Philippe; Regnault, Julie; Schurr, Frank; Dubois, Eric; Ribière, Magali

2012-03-01

Chronic bee paralysis virus (CBPV) is responsible for chronic bee paralysis, an infectious and contagious disease in adult honey bees (Apis mellifera L.). A real-time RT-PCR assay to quantitate the CBPV load is now available. To propose this assay as a reference method, it was characterised further in an intra-laboratory study during which the reliability and the repeatability of results and the performance of the assay were confirmed. The qPCR assay alone and the whole quantitation method (from sample RNA extraction to analysis) were both assessed following the ISO/IEC 17025 standard and the recent XP U47-600 standard issued by the French Standards Institute. The performance of the qPCR assay and of the overall CBPV quantitation method were validated over a 6 log range from 10(2) to 10(8) with a detection limit of 50 and 100 CBPV RNA copies, respectively, and the protocol of the real-time RT-qPCR assay for CBPV quantitation was approved by the French Accreditation Committee. Copyright © 2011 Elsevier B.V. All rights reserved.

The behaviour change wheel: A new method for characterising and designing behaviour change interventions

PubMed Central

2011-01-01

Background Improving the design and implementation of evidence-based practice depends on successful behaviour change interventions. This requires an appropriate method for characterising interventions and linking them to an analysis of the targeted behaviour. There exists a plethora of frameworks of behaviour change interventions, but it is not clear how well they serve this purpose. This paper evaluates these frameworks, and develops and evaluates a new framework aimed at overcoming their limitations. Methods A systematic search of electronic databases and consultation with behaviour change experts were used to identify frameworks of behaviour change interventions. These were evaluated according to three criteria: comprehensiveness, coherence, and a clear link to an overarching model of behaviour. A new framework was developed to meet these criteria. The reliability with which it could be applied was examined in two domains of behaviour change: tobacco control and obesity. Results Nineteen frameworks were identified covering nine intervention functions and seven policy categories that could enable those interventions. None of the frameworks reviewed covered the full range of intervention functions or policies, and only a minority met the criteria of coherence or linkage to a model of behaviour. At the centre of a proposed new framework is a 'behaviour system' involving three essential conditions: capability, opportunity, and motivation (what we term the 'COM-B system'). This forms the hub of a 'behaviour change wheel' (BCW) around which are positioned the nine intervention functions aimed at addressing deficits in one or more of these conditions; around this are placed seven categories of policy that could enable those interventions to occur. The BCW was used reliably to characterise interventions within the English Department of Health's 2010 tobacco control strategy and the National Institute of Health and Clinical Excellence's guidance on reducing obesity

Laboratory theory and methods for sediment analysis

USGS Publications Warehouse

Guy, Harold P.

1969-01-01

The diverse character of fluvial sediments makes the choice of laboratory analysis somewhat arbitrary and the pressing of sediment samples difficult. This report presents some theories and methods used by the Water Resources Division for analysis of fluvial sediments to determine the concentration of suspended-sediment samples and the particle-size distribution of both suspended-sediment and bed-material samples. Other analyses related to these determinations may include particle shape, mineral content, and specific gravity, the organic matter and dissolved solids of samples, and the specific weight of soils. The merits and techniques of both the evaporation and filtration methods for concentration analysis are discussed. Methods used for particle-size analysis of suspended-sediment samples may include the sieve pipet, the VA tube-pipet, or the BW tube-VA tube depending on the equipment available, the concentration and approximate size of sediment in the sample, and the settling medium used. The choice of method for most bed-material samples is usually limited to procedures suitable for sand or to some type of visual analysis for large sizes. Several tested forms are presented to help insure a well-ordered system in the laboratory to handle the samples, to help determine the kind of analysis required for each, to conduct the required processes, and to assist in the required computations. Use of the manual should further 'standardize' methods of fluvial sediment analysis among the many laboratories and thereby help to achieve uniformity and precision of the data.

Current Application of Capillary Electrophoresis in Nanomaterial Characterisation and Its Potential to Characterise the Protein and Small Molecule Corona

PubMed Central

Guggenheim, Emily J.; Briffa, Sophie M.; Thorn, James A.; Lynch, Iseult; Valsami-Jones, Eugenia

2018-01-01

Due to the increasing use and production of nanomaterials (NMs), the ability to characterise their physical/chemical properties quickly and reliably has never been so important. Proper characterisation allows a thorough understanding of the material and its stability, and is critical to establishing dose-response curves to ascertain risks to human and environmental health. Traditionally, methods such as Transmission Electron Microscopy (TEM), Field Flow Fractionation (FFF) and Dynamic Light Scattering (DLS) have been favoured for size characterisation, due to their wide-availability and well-established protocols. Capillary Electrophoresis (CE) offers a faster and more cost-effective solution for complex dispersions including polydisperse or non-spherical NMs. CE has been used to rapidly separate NMs of varying sizes, shapes, surface modifications and compositions. This review will discuss the literature surrounding the CE separation techniques, detection and NM characteristics used for the analysis of a wide range of NMs. The potential of combining CE with mass spectrometry (CE-MS) will also be explored to further expand the characterisation of NMs, including the layer of biomolecules adsorbed to the surface of NMs in biological or environmental compartments, termed the acquired biomolecule corona. CE offers the opportunity to uncover new/poorly characterised low abundance and polar protein classes due to the high ionisation efficiency of CE-MS. Furthermore, the possibility of using CE-MS to characterise the poorly researched small molecule interactions within the NM corona is discussed. PMID:29439415

Inflamed juvenile conjunctival naevus: clinicopathological characterisation

PubMed Central

Zamir, Ehud; Mechoulam, Hadas; Micera, Alessandra; Levi-Schaffer, Francesca; Pe'er, Jacob

2002-01-01

Aim: Inflamed juvenile conjunctival naevi (IJCN) are often erroneously suspected to be malignant because of rapid growth. Their clinical and histopathological features have not been characterised in series of patients. The aim of the study is to characterise IJCN clinically and histopathologically. Methods: This is a retrospective non-randomised clinicopathological study. All patients younger than 20 years with conjunctival naevi which were excised between 1990 and 2000 were included. The clinical signs of the affected patients and the histopathological findings of the excised lesions were characterised. Results: A total of 63 conjunctival naevi were resected. 25% of the patients had simple compound conjunctival naevi and 75% had compound naevi with prominent inflammatory histological features (discrete lymphocyte aggregates, plasma cells, and eosinophils). Epithelial cysts and solid epithelial islands were common in the IJCN. The IJCN were all located at or near the limbus, and characterised by recurrent periods of congestion and growth. 75% of the IJCN patients with complete medical records had a history of allergic disease. Marked conjunctival papillary reaction was present in all of the patients, indicating a possible conjunctival allergy. Conclusions: IJCN is a unique entity, different from simple compound conjunctival naevus. Its association with allergic conjunctivitis is suggestive, and despite periods of alarmingly rapid growth, is histologically benign. PMID:11801498

Analytical difficulties facing today's regulatory laboratories: issues in method validation.

PubMed

MacNeil, James D

2012-08-01

The challenges facing analytical laboratories today are not unlike those faced in the past, although both the degree of complexity and the rate of change have increased. Challenges such as development and maintenance of expertise, maintenance and up-dating of equipment, and the introduction of new test methods have always been familiar themes for analytical laboratories, but international guidelines for laboratories involved in the import and export testing of food require management of such changes in a context which includes quality assurance, accreditation, and method validation considerations. Decisions as to when a change in a method requires re-validation of the method or on the design of a validation scheme for a complex multi-residue method require a well-considered strategy, based on a current knowledge of international guidance documents and regulatory requirements, as well the laboratory's quality system requirements. Validation demonstrates that a method is 'fit for purpose', so the requirement for validation should be assessed in terms of the intended use of a method and, in the case of change or modification of a method, whether that change or modification may affect a previously validated performance characteristic. In general, method validation involves method scope, calibration-related parameters, method precision, and recovery. Any method change which may affect method scope or any performance parameters will require re-validation. Some typical situations involving change in methods are discussed and a decision process proposed for selection of appropriate validation measures. © 2012 John Wiley & Sons, Ltd.

Bootstrapping Methods Applied for Simulating Laboratory Works

ERIC Educational Resources Information Center

Prodan, Augustin; Campean, Remus

2005-01-01

Purpose: The aim of this work is to implement bootstrapping methods into software tools, based on Java. Design/methodology/approach: This paper presents a category of software e-tools aimed at simulating laboratory works and experiments. Findings: Both students and teaching staff use traditional statistical methods to infer the truth from sample…

Implementation of a chemical background method (OH-CHEM) for measurements of OH using the Leeds FAGE instrument: Characterisation and observations from a coastal location

NASA Astrophysics Data System (ADS)

Woodward-Massey, R.; Cryer, D. R.; Whalley, L. K.; Ingham, T.; Seakins, P. W.; Heard, D. E.; Stimpson, L. M.

2015-12-01

The removal of pollutants and greenhouse gases in the troposphere is dominated by reactions with the hydroxyl radical (OH), which is closely coupled to the hydroperoxy radical (HO2). Comparisons of the levels of OH and HO2 observed during field campaigns to the results of detailed chemical box models serve as a vital tool to assess our understanding of the underlying chemical mechanisms involved in tropospheric oxidation. Recent measurements of OH and HO2 radicals are significantly higher than those predicted by models for some instruments measuring in certain environments, especially those influenced by high emissions of biogenic compounds such as isoprene, prompting intense laboratory research to account for such discrepancies. While current chemical mechanisms are likely incomplete, it is also possible that, at least in part, these elevated radical observations have been influenced by instrumental biases from interfering species. Recent studies have suggested that fluorescence assay by gas expansion (FAGE) instruments may be susceptible to an unknown interference in the measurement of OH. This hypothesis can be tested through the implementation of an alternative method to determine the OH background signal, whereby OH is removed by the addition of a chemical scavenger prior to sampling by FAGE. The Leeds FAGE instrument was modified to facilitate this method by the construction of an inlet pre-injector (IPI), where OH is removed through reaction with propane. The modified Leeds FAGE instrument was deployed at a coastal location in southeast England during summer 2015 as part of the ICOZA (Integrated Chemistry of OZone in the Atmosphere) project. Measurements of OH made using both background methods will be presented, alongside results from laboratory characterisation experiments and details of the IPI design.

Overview of EPA Pesticide Laboratories and Methods

EPA Pesticide Factsheets

EPA operates two pesticide laboratories that provide a variety of technical services to the Agency, other federal and state agencies, tribal groups and other organizations.The labs develop methods and procedures.

New characterisation method of electrical and electronic equipment wastes (WEEE).

PubMed

Menad, N; Guignot, S; van Houwelingen, J A

2013-03-01

Innovative separation and beneficiation techniques of various materials encountered in electrical and electronic equipment wastes (WEEE) is a major improvement for its recycling. Mechanical separation-oriented characterisation of WEEE was conducted in an attempt to evaluate the amenability of mechanical separation processes. Properties such as liberation degree of fractions (plastics, metals ferrous and non-ferrous), which are essential for mechanical separation, are analysed by means of a grain counting approach. Two different samples from different recycling industries were characterised in this work. The first sample is a heterogeneous material containing different types of plastics, metals (ferrous and non-ferrous), printed circuit board (PCB), rubber and wood. The second sample contains a mixture of mainly plastics. It is found for the first sample that all aluminium particles are free (100%) in all investigated size fractions. Between 92% and 95% of plastics are present as free particles; however, 67% in average of ferromagnetic particles are liberated. It can be observed that only 42% of ferromagnetic particles are free in the size fraction larger than 20mm. Particle shapes were also quantified manually particle by particle. The results show that the particle shapes as a result of shredding, turn out to be heterogeneous, thereby complicating mechanical separation processes. In addition, the separability of various materials was ascertained by a sink-float analysis and eddy current separation. The second sample was separated by automatic sensor sorting in four different products: ABS, PC-ABS, PS and rest product. The fractions were characterised by using the methodology described in this paper. The results show that the grade and liberation degree of the plastic products ABS, PC-ABS and PS are close to 100%. Sink-float separation and infrared plastic identification equipment confirms the high plastic quality. On the basis of these findings, a global

The behaviour change wheel: a new method for characterising and designing behaviour change interventions.

PubMed

Michie, Susan; van Stralen, Maartje M; West, Robert

2011-04-23

Improving the design and implementation of evidence-based practice depends on successful behaviour change interventions. This requires an appropriate method for characterising interventions and linking them to an analysis of the targeted behaviour. There exists a plethora of frameworks of behaviour change interventions, but it is not clear how well they serve this purpose. This paper evaluates these frameworks, and develops and evaluates a new framework aimed at overcoming their limitations. A systematic search of electronic databases and consultation with behaviour change experts were used to identify frameworks of behaviour change interventions. These were evaluated according to three criteria: comprehensiveness, coherence, and a clear link to an overarching model of behaviour. A new framework was developed to meet these criteria. The reliability with which it could be applied was examined in two domains of behaviour change: tobacco control and obesity. Nineteen frameworks were identified covering nine intervention functions and seven policy categories that could enable those interventions. None of the frameworks reviewed covered the full range of intervention functions or policies, and only a minority met the criteria of coherence or linkage to a model of behaviour. At the centre of a proposed new framework is a 'behaviour system' involving three essential conditions: capability, opportunity, and motivation (what we term the 'COM-B system'). This forms the hub of a 'behaviour change wheel' (BCW) around which are positioned the nine intervention functions aimed at addressing deficits in one or more of these conditions; around this are placed seven categories of policy that could enable those interventions to occur. The BCW was used reliably to characterise interventions within the English Department of Health's 2010 tobacco control strategy and the National Institute of Health and Clinical Excellence's guidance on reducing obesity. Interventions and policies to

Application of computational methods to the design and characterisation of porous molecular materials.

PubMed

Evans, Jack D; Jelfs, Kim E; Day, Graeme M; Doonan, Christian J

2017-06-06

Composed from discrete units, porous molecular materials (PMMs) possess unique properties not observed for conventional, extended, solids, such as solution processibility and permanent porosity in the liquid phase. However, identifying the origin of porosity is not a trivial process, especially for amorphous or liquid phases. Furthermore, the assembly of molecular components is typically governed by a subtle balance of weak intermolecular forces that makes structure prediction challenging. Accordingly, in this review we canvass the crucial role of molecular simulations in the characterisation and design of PMMs. We will outline strategies for modelling porosity in crystalline, amorphous and liquid phases and also describe the state-of-the-art methods used for high-throughput screening of large datasets to identify materials that exhibit novel performance characteristics.

An observational assessment method for aging laboratory rats

EPA Science Inventory

The growth of the aging population highlights the need for laboratory animal models to study the basic biological processes ofaging and susceptibility to toxic chemicals and disease. Methods to evaluate health ofaging animals over time are needed, especially efficient methods for...

Preparation and characterisation of isotopically enriched Ta2O5 targets for nuclear astrophysics studies

NASA Astrophysics Data System (ADS)

Caciolli, A.; Scott, D. A.; Di Leva, A.; Formicola, A.; Aliotta, M.; Anders, M.; Bellini, A.; Bemmerer, D.; Broggini, C.; Campeggio, M.; Corvisiero, P.; Depalo, R.; Elekes, Z.; Fülöp, Zs.; Gervino, G.; Guglielmetti, A.; Gustavino, C.; Gyürky, Gy.; Imbriani, G.; Junker, M.; Marta, M.; Menegazzo, R.; Napolitani, E.; Prati, P.; Rigato, V.; Roca, V.; Rolfs, C.; Rossi Alvarez, C.; Somorjai, E.; Salvo, C.; Straniero, O.; Strieder, F.; Szücs, T.; Terrasi, F.; Trautvetter, H. P.; Trezzi, D.

2012-10-01

The direct measurement of reaction cross-sections at astrophysical energies often requires the use of solid targets of known thickness, isotopic composition, and stoichiometry that are able to withstand high beam currents for extended periods of time. Here, we report on the production and characterisation of isotopically enriched Ta2O5 targets for the study of proton-induced reactions at the Laboratory for Underground Nuclear Astrophysics facility of the Laboratori Nazionali del Gran Sasso. The targets were prepared by anodisation of tantalum backings in enriched water (up to 66% in 17O and up to 96% in 18O. Special care was devoted to minimising the presence of any contaminants that could induce unwanted background reactions with the beam in the energy region of astrophysical interest. Results from target characterisation measurements are reported, and the conclusions for proton capture measurements with these targets are drawn.

DNA-Based Methods in the Immunohematology Reference Laboratory

PubMed Central

Denomme, Gregory A

2010-01-01

Although hemagglutination serves the immunohematology reference laboratory well, when used alone, it has limited capability to resolve complex problems. This overview discusses how molecular approaches can be used in the immunohematology reference laboratory. In order to apply molecular approaches to immunohematology, knowledge of genes, DNA-based methods, and the molecular bases of blood groups are required. When applied correctly, DNA-based methods can predict blood groups to resolve ABO/Rh discrepancies, identify variant alleles, and screen donors for antigen-negative units. DNA-based testing in immunohematology is a valuable tool used to resolve blood group incompatibilities and to support patients in their transfusion needs. PMID:21257350

Laboratory evaluation of polychlorinated biphenyls encapsulation methods

EPA Science Inventory

Effectiveness and limitations of the encapsulation method for reducing polychlorinated biphenyls (PCBs) concentrations in indoor air and contaminated surface have been evaluated in the laboratory study. Ten coating materials such as epoxy and polyurethane coatings, latex paint, a...

Laboratory Characterization of Cemented Rock Fill for Underhand Cut and Fill Method of Mining

NASA Astrophysics Data System (ADS)

Kumar, Dinesh; Singh, Upendra Kumar; Singh, Gauri Shankar Prasad

2016-10-01

Backfilling with controlled specifications is employed for improved ground support and pillar recovery in underground metalliferous mine workings. This paper reports the results of a laboratory study to characterise various mechanical properties of cemented rock fill (CRF) formulations for different compaction levels and cement content percentage for use in underhand cut and fill method of mining. Laboratory test set ups and procedures have been described for conducting compressive and bending tests of CRF block samples. A three dimensional numerical modelling study has also been carried out to overcome the limitations arising due to non-standard dimension of test blocks used in flexural loading test and the test setup devised for this purpose. Based on these studies, specific relations have been established between the compressive and the flexural properties of the CRF. The flexural strength of the wire mesh reinforced CRF is also correlated with its residual strength and the Young's modulus of elasticity under flexural loading condition. The test results of flexural strength, residual flexural strength and modulus show almost linear relations with cement content in CRF. The compressive strength of the CRF block samples is estimated as seven times the flexural strength whereas the compressive modulus is four times the flexural modulus. It has been found that the strengths of CRF of low compaction and no compaction are 75 and 60 % respectively to that of the medium compaction CRF. The relation between the strength and the unit weight of CRF as obtained in this study is significantly important for design and quality control of CRF during its large scale application in underhand cut and fill stopes.

Laboratory assessment of novel oral anticoagulants: method suitability and variability between coagulation laboratories.

PubMed

Helin, Tuukka A; Pakkanen, Anja; Lassila, Riitta; Joutsi-Korhonen, Lotta

2013-05-01

Laboratory tests to assess novel oral anticoagulants (NOACs) are under evaluation. Routine monitoring is unnecessary, but under special circumstances bioactivity assessment becomes crucial. We analyzed the effects of NOACs on coagulation tests and the availability of specific assays at different laboratories. Plasma samples spiked with dabigatran (Dabi; 120 and 300 μg/L) or rivaroxaban (Riva; 60, 146, and 305 μg/L) were sent to 115 and 38 European laboratories, respectively. International normalized ratio (INR) and activated partial thromboplastin time (APTT) were analyzed for all samples; thrombin time (TT) was analyzed specifically for Dabi and calibrated anti-activated factor X (anti-Xa) activity for Riva. We compared the results with patient samples. Results of Dabi samples were reported by 73 laboratories (13 INR and 9 APTT reagents) and Riva samples by 22 laboratories (5 INR and 4 APTT reagents). Both NOACs increased INR values; the increase was modest, albeit larger, for Dabi, with higher CV, especially with Quick (vs Owren) methods. Both NOACs dose-dependently prolonged the APTT. Again, the prolongation and CVs were larger for Dabi. The INR and APTT results varied reagent-dependently (P < 0.005), with less prolongation in patient samples. TT results (Dabi) and calibrated anti-Xa results (Riva) were reported by only 11 and 8 laboratories, respectively. The screening tests INR and APTT are suboptimal in assessing NOACs, having high reagent dependence and low sensitivity and specificity. They may provide information, if laboratories recognize their limitations. The variation will likely increase and the sensitivity differ in clinical samples. Specific assays measure NOACs accurately; however, few laboratories applied them. © 2013 American Association for Clinical Chemistry.

Sensitive fluorescent in situ hybridisation method for the characterisation of breast cancer cells in bone marrow aspirates.

PubMed Central

Forus, A; Høifødt, H K; Overli, G E; Myklebost, O; Fodstad, O

1999-01-01

AIM: The presence of malignant cells in the blood and bone marrow of patients with cancer at the time of surgery may be indicative of early relapse. In addition to their numbers, the phenotypes of the micrometastatic cells might be essential in determining whether overt metastases will develop. This study aimed to establish a sensitive method for the detection and characterisation of malignant cells present in bone marrow. METHODS: In spiking experiments, SKBR3 cells were mixed with mononuclear cells in known proportions to mimic bone marrow samples with micrometastatic cells. Tumour cells were extracted using SAM-M450 Dynabeads coupled to the MOC-31 anti-epithelial antibody, and were further analysed for amplification of erbB2 and int2 by fluorescent in situ hybridisation (FISH). erbB2 and int2 copy numbers were also determined in 15 primary breast cancers, and bone marrow samples from patients with amplification were analysed for micrometastatic cells by immunomagnetic enrichment and FISH. RESULTS: In model experiments, cells with amplification could be detected in bead selected fractions when ratios of tumour cells (SKBR3) to mononuclear cells were as low as 10:10(7). Among the tumour samples, eight showed increased copy numbers of erbB2 and/or int2, and three of these patients had detectable numbers of tumour cells in their bone marrow: 4000, 540, and 26 tumour cells/10(7) mononuclear cells, respectively. The patient with 540 tumour cells/10(7) mononuclear cells showed high level amplification of erbB2 and suffered from a particularly aggressive disease, whereas the patient with 4000 tumour cells/10(7) mononuclear cells had favourable disease progression. CONCLUSION: These results demonstrate the feasibility and advantage of combining immunomagnetic selection and FISH characterisation of cancer cells in bone marrow samples. It is possible that molecular characterisation of such cells could provide prognostically valuable information. PMID:10474684

Hydroxyapatite, fluor-hydroxyapatite and fluorapatite produced via the sol-gel method. Optimisation, characterisation and rheology.

PubMed

Tredwin, Christopher J; Young, Anne M; Georgiou, George; Shin, Song-Hee; Kim, Hae-Won; Knowles, Jonathan C

2013-02-01

Currently, most titanium implant coatings are made using hydroxyapatite and a plasma spraying technique. There are however limitations associated with plasma spraying processes including poor adherence, high porosity and cost. An alternative method utilising the sol-gel technique offers many potential advantages but is currently lacking research data for this application. It was the objective of this study to characterise and optimise the production of Hydroxyapatite (HA), fluorhydroxyapatite (FHA) and fluorapatite (FA) using a sol-gel technique and assess the rheological properties of these materials. HA, FHA and FA were synthesised by a sol-gel method. Calcium nitrate and triethylphosphite were used as precursors under an ethanol-water based solution. Different amounts of ammonium fluoride (NH4F) were incorporated for the preparation of the sol-gel derived FHA and FA. Optimisation of the chemistry and subsequent characterisation of the sol-gel derived materials was carried out using X-ray Diffraction (XRD) and Differential Thermal Analysis (DTA). Rheology of the sol-gels was investigated using a viscometer and contact angle measurement. A protocol was established that allowed synthesis of HA, FHA and FA that were at least 99% phase pure. The more fluoride incorporated into the apatite structure; the lower the crystallisation temperature, the smaller the unit cell size (changes in the a-axis), the higher the viscosity and contact angle of the sol-gel derived apatite. A technique has been developed for the production of HA, FHA and FA by the sol-gel technique. Increasing fluoride substitution in the apatite structure alters the potential coating properties. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Manual of analytical methods for the Environmental Health Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gray, C. E.

1975-06-01

This manual was compiled from techniques used In the Environmental Health Laboratory of Sandia Laboratories at Albuquerque. New Mexico, and is a revision of an earlier publication (SC-M-07-3044) edited by Lial W. Brewer. The procedures arc similar to those used in other laboratories devoted to Environmental Health practices. Some of the methods are standard and others are modified to suit our needs; others were developed at Sandia. The author has attempted to present all methods in a simple and concise manner, but in sufficient detail to make them readily usable. It is not inferred that the methods are universal formore » any type of sample, but they have been found very reliable for the types of samples mentioned. The author will welcome inquiry for clarification of any part of this manual. It is the desire of the author that this manual will be of use and service to others. New and revised procedures will be issued as supplements to this document.« less

Environmental characterisation of coal mine waste rock in the field: an example from New Zealand

NASA Astrophysics Data System (ADS)

Hughes, J.; Craw, D.; Peake, B.; Lindsay, P.; Weber, P.

2007-08-01

Characterisation of mine waste rock with respect to acid generation potential is a necessary part of routine mine operations, so that environmentally benign waste rock stacks can be constructed for permanent storage. Standard static characterisation techniques, such as acid neutralisation capacity (ANC), maximum potential acidity, and associated acid-base accounting, require laboratory tests that can be difficult to obtain rapidly at remote mine sites. We show that a combination of paste pH and a simple portable carbonate dissolution test, both techniques that can be done in the field in a 15 min time-frame, is useful for distinguishing rocks that are potentially acid-forming from those that are acid-neutralising. Use of these techniques could allow characterisation of mine wastes at the metre scale during mine excavation operations. Our application of these techniques to pyrite-bearing (total S = 1-4 wt%) but variably calcareous coal mine overburden shows that there is a strong correlation between the portable carbonate dissolution technique and laboratory-determined ANC measurements (range of 0-10 wt% calcite equivalent). Paste pH measurements on the same rocks are bimodal, with high-sulphur, low-calcite rocks yielding pH near 3 after 10 min, whereas high-ANC rocks yield paste pH of 7-8. In our coal mine example, the field tests were most effective when used in conjunction with stratigraphy. However, the same field tests have potential for routine use in any mine in which distinction of acid-generating rocks from acid-neutralising rocks is required. Calibration of field-based acid-base accounting characteristics of the rocks with laboratory-based static and/or kinetic tests is still necessary.

Laboratory based instruction in Pakistan: Comparative evaluation of three laboratory instruction methods in biological science at higher secondary school level

NASA Astrophysics Data System (ADS)

Cheema, Tabinda Shahid

This study of laboratory based instruction at higher secondary school level was an attempt to gain some insight into the effectiveness of three laboratory instruction methods: cooperative group instruction method, individualised instruction method and lecture demonstration method on biology achievement and retention. A Randomised subjects, Pre-test Post-test Comparative Methods Design was applied. Three groups of students from a year 11 class in Pakistan conducted experiments using the different laboratory instruction methods. Pre-tests, achievement tests after the experiments and retention tests one month later were administered. Results showed no significant difference between the groups on total achievement and retention, nor was there any significant difference on knowledge and comprehension test scores or skills performance. Future research investigating a similar problem is suggested.

Valid methods: the quality assurance of test method development, validation, approval, and transfer for veterinary testing laboratories.

PubMed

Wiegers, Ann L

2003-07-01

Third-party accreditation is a valuable tool to demonstrate a laboratory's competence to conduct testing. Accreditation, internationally and in the United States, has been discussed previously. However, accreditation is only I part of establishing data credibility. A validated test method is the first component of a valid measurement system. Validation is defined as confirmation by examination and the provision of objective evidence that the particular requirements for a specific intended use are fulfilled. The international and national standard ISO/IEC 17025 recognizes the importance of validated methods and requires that laboratory-developed methods or methods adopted by the laboratory be appropriate for the intended use. Validated methods are therefore required and their use agreed to by the client (i.e., end users of the test results such as veterinarians, animal health programs, and owners). ISO/IEC 17025 also requires that the introduction of methods developed by the laboratory for its own use be a planned activity conducted by qualified personnel with adequate resources. This article discusses considerations and recommendations for the conduct of veterinary diagnostic test method development, validation, evaluation, approval, and transfer to the user laboratory in the ISO/IEC 17025 environment. These recommendations are based on those of nationally and internationally accepted standards and guidelines, as well as those of reputable and experienced technical bodies. They are also based on the author's experience in the evaluation of method development and transfer projects, validation data, and the implementation of quality management systems in the area of method development.

Sediment laboratory quality-assurance project: studies of methods and materials

USGS Publications Warehouse

Gordon, J.D.; Newland, C.A.; Gray, J.R.

2001-01-01

In August 1996 the U.S. Geological Survey initiated the Sediment Laboratory Quality-Assurance project. The Sediment Laboratory Quality Assurance project is part of the National Sediment Laboratory Quality-Assurance program. This paper addresses the fmdings of the sand/fme separation analysis completed for the single-blind reference sediment-sample project and differences in reported results between two different analytical procedures. From the results it is evident that an incomplete separation of fme- and sand-size material commonly occurs resulting in the classification of some of the fme-size material as sand-size material. Electron microscopy analysis supported the hypothesis that the negative bias for fme-size material and the positive bias for sand-size material is largely due to aggregation of some of the fine-size material into sand-size particles and adherence of fine-size material to the sand-size grains. Electron microscopy analysis showed that preserved river water, which was low in dissolved solids, specific conductance, and neutral pH, showed less aggregation and adhesion than preserved river water that was higher in dissolved solids and specific conductance with a basic pH. Bacteria were also found growing in the matrix, which may enhance fme-size material aggregation through their adhesive properties. Differences between sediment-analysis methods were also investigated as pan of this study. Suspended-sediment concentration results obtained from one participating laboratory that used a total-suspended solids (TSS) method had greater variability and larger negative biases than results obtained when this laboratory used a suspended-sediment concentration method. When TSS methods were used to analyze the reference samples, the median suspended sediment concentration percent difference was -18.04 percent. When the laboratory used a suspended-sediment concentration method, the median suspended-sediment concentration percent difference was -2

DO TIE LABORATORY BASED METHODS REALLY REFLECT FIELD CONDITIONS

EPA Science Inventory

Sediment Toxicity Identification and Evaluation (TIE) methods have been developed for both interstitial waters and whole sediments. These relatively simple laboratory methods are designed to identify specific toxicants or classes of toxicants in sediments; however, the question ...

Laboratory-based versus non-laboratory-based method for assessment of cardiovascular disease risk: the NHANES I Follow-up Study cohort

PubMed Central

Gaziano, Thomas A; Young, Cynthia R; Fitzmaurice, Garrett; Atwood, Sidney; Gaziano, J Michael

2008-01-01

Summary Background Around 80% of all cardiovascular deaths occur in developing countries. Assessment of those patients at high risk is an important strategy for prevention. Since developing countries have limited resources for prevention strategies that require laboratory testing, we assessed if a risk prediction method that did not require any laboratory tests could be as accurate as one requiring laboratory information. Methods The National Health and Nutrition Examination Survey (NHANES) was a prospective cohort study of 14 407 US participants aged between 25–74 years at the time they were first examined (between 1971 and 1975). Our follow-up study population included participants with complete information on these surveys who did not report a history of cardiovascular disease (myocardial infarction, heart failure, stroke, angina) or cancer, yielding an analysis dataset N=6186. We compared how well either method could predict first-time fatal and non-fatal cardiovascular disease events in this cohort. For the laboratory-based model, which required blood testing, we used standard risk factors to assess risk of cardiovascular disease: age, systolic blood pressure, smoking status, total cholesterol, reported diabetes status, and current treatment for hypertension. For the non-laboratory-based model, we substituted body-mass index for cholesterol. Findings In the cohort of 6186, there were 1529 first-time cardiovascular events and 578 (38%) deaths due to cardiovascular disease over 21 years. In women, the laboratory-based model was useful for predicting events, with a c statistic of 0·829. The c statistic of the non-laboratory-based model was 0·831. In men, the results were similar (0·784 for the laboratory-based model and 0·783 for the non-laboratory-based model). Results were similar between the laboratory-based and non-laboratory-based models in both men and women when restricted to fatal events only. Interpretation A method that uses non-laboratory

Analysis of laboratory compaction methods of roller compacted concrete

NASA Astrophysics Data System (ADS)

Trtík, Tomáš; Chylík, Roman; Bílý, Petr; Fládr, Josef

2017-09-01

Roller-Compacted Concrete (RCC) is an ordinary concrete poured and compacted with machines typically used for laying of asphalt road layers. One of the problems connected with this technology is preparation of representative samples in the laboratory. The aim of this work was to analyse two methods of preparation of RCC laboratory samples with bulk density as the comparative parameter. The first method used dynamic compaction by pneumatic hammer. The second method of compaction had a static character. The specimens were loaded by precisely defined force in laboratory loading machine to create the same conditions as during static rolling (in the Czech Republic, only static rolling is commonly used). Bulk densities obtained by the two compaction methods were compared with core drills extracted from real RCC structure. The results have shown that the samples produced by pneumatic hammer tend to overestimate the bulk density of the material. For both compaction methods, immediate bearing index test was performed to verify the quality of compaction. A fundamental difference between static and dynamic compaction was identified. In static compaction, initial resistance to penetration of the mandrel was higher, after exceeding certain limit the resistance was constant. This means that the samples were well compacted just on the surface. Specimens made by pneumatic hammer actively resisted throughout the test, the whole volume was uniformly compacted.

Quantification and characterisation of fatty acid methyl esters in microalgae: Comparison of pretreatment and purification methods.

PubMed

Lage, Sandra; Gentili, Francesco G

2018-06-01

A systematic qualitative and quantitative analysis of fatty acid methyl esters (FAMEs) is crucial for microalgae species selection for biodiesel production. The aim of this study is to identify the best method to assess microalgae FAMEs composition and content. A single-step method, was tested with and without purification steps-that is, separation of lipid classes by thin-layer chromatography (TLC) or solid-phase extraction (SPE). The efficiency of a direct transesterification method was also evaluated. Additionally, the yield of the FAMEs and the profiles of the microalgae samples with different pretreatments (boiled in isopropanol, freezing, oven-dried and freeze-dried) were compared. The application of a purification step after lipid extraction proved to be essential for an accurate FAMEs characterisation. The purification methods, which included TLC and SPE, provided superior results compared to not purifying the samples. Freeze-dried microalgae produced the lowest FAMEs yield. However, FAMEs profiles were generally equivalent among the pretreatments. Copyright © 2018 Elsevier Ltd. All rights reserved.

A comparison of two microscale laboratory reporting methods in a secondary chemistry classroom

NASA Astrophysics Data System (ADS)

Martinez, Lance Michael

This study attempted to determine if there was a difference between the laboratory achievement of students who used a modified reporting method and those who used traditional laboratory reporting. The study also determined the relationships between laboratory performance scores and the independent variables score on the Group Assessment of Logical Thinking (GALT) test, chronological age in months, gender, and ethnicity for each of the treatment groups. The study was conducted using 113 high school students who were enrolled in first-year general chemistry classes at Pueblo South High School in Colorado. The research design used was the quasi-experimental Nonequivalent Control Group Design. The statistical treatment consisted of the Multiple Regression Analysis and the Analysis of Covariance. Based on the GALT, students in the two groups were generally in the concrete and transitional stages of the Piagetian cognitive levels. The findings of the study revealed that the traditional and the modified methods of laboratory reporting did not have any effect on the laboratory performance outcome of the subjects. However, the students who used the traditional method of reporting showed a higher laboratory performance score when evaluation was conducted using the New Standards rubric recommended by the state. Multiple Regression Analysis revealed that there was a significant relationship between the criterion variable student laboratory performance outcome of individuals who employed traditional laboratory reporting methods and the composite set of predictor variables. On the contrary, there was no significant relationship between the criterion variable student laboratory performance outcome of individuals who employed modified laboratory reporting methods and the composite set of predictor variables.

Performance evaluation of elemental analysis/isotope ratio mass spectrometry methods for the determination of the D/H ratio in tetramethylurea and other compounds--results of a laboratory inter-comparison.

PubMed

Bréas, Olivier; Thomas, Freddy; Zeleny, Reinhard; Calderone, Giovanni; Jamin, Eric; Guillou, Claude

2007-01-01

Tetramethylurea (TMU) with a certified D/H ratio is the internal standard for Site-specific Natural Isotope Fractionation measured by Nuclear Magnetic Resonance (SNIF-NMR) analysis of wine ethanol for detection of possible adulterations (Commission Regulation 2676/90). A new batch of a TMU certified reference material (CRM) is currently being prepared. Whereas SNIF-NMR has been employed up to now, Elemental Analysis/Isotope Ratio Mass Spectrometry ((2)H-EA-IRMS) was envisaged as the method of choice for value assignment of the new CRM, as more precise (better repeatable) data might be obtained, resulting in lower uncertainty of the certified value. In order to evaluate the accuracy and intra- and inter-laboratory reproducibility of (2)H-EA-IRMS methods, a laboratory inter-comparison was carried out by analysing TMU and other organic compounds, as well as some waters. The results revealed that experienced laboratories are capable of generating robust and well comparable data, which highlights the emerging potential of IRMS in food authenticity testing. However, a systematic bias between IRMS and SNIF-NMR reference data was observed for TMU; this lack of data consistency rules out the (2)H-IRMS technique for the characterisation measurement of the new TMU CRM.

Stand-alone error characterisation of microwave satellite soil moisture using a Fourier method

USDA-ARS?s Scientific Manuscript database

Error characterisation of satellite-retrieved soil moisture (SM) is crucial for maximizing their utility in research and applications in hydro-meteorology and climatology. Error characteristics can provide insights for retrieval development and validation, and inform suitable strategies for data fus...

Analytical Characterisation of Nanoscale Zero-Valent Iron: A ...

EPA Pesticide Factsheets

Zero-valent iron nanoparticles (nZVI) have been widely tested as they are showing significant promise for environmental remediation. However, many recent studies have demonstrated that their mobility and reactivity in subsurface environments are significantly affected by their tendency to aggregate. Both the mobility and reactivity of nZVI mainly depends on properties such as particle size, surface chemistry and bulk composition. In order to ensure efficient remediation, it is crucial to accurately assess and understand the implications of these properties before deploying these materials into contaminated environments. Many analytical techniques are now available to determine these parameters and this paper provides a critical review of their usefulness and limitations for nZVI characterisation. These analytical techniques include microscopy and light scattering techniques for the determination of particle size, size distribution and aggregation state, and X-ray techniques for the characterisation of surface chemistry and bulk composition. Example characterisation data derived from commercial nZVI materials is used to further illustrate method strengths and limitations. Finally, some important challenges with respect to the characterisation of nZVI in groundwater samples are discussed. In recent years, manufactured nanoparticles (MNPs) have attracted increasing interest for their potential applications in the treatment of contaminated soil and water. In compar

Comparison of Instream and Laboratory Methods of Measuring Sediment Oxygen Demand

USGS Publications Warehouse

Hall, Dennis C.; Berkas, Wayne R.

1988-01-01

Sediment oxygen demand (SOD) was determined at three sites in a gravel-bottomed central Missouri stream by: (1) two variations of an instream method, and (2) a laboratory method. SOD generally was greatest by the instream methods, which are considered more accurate, and least by the laboratory method. Disturbing stream sediment did not significantly decrease SOD by the instream method. Temperature ranges of up to 12 degree Celsius had no significant effect on the SOD. In the gravel-bottomed stream, the placement of chambers was critical to obtain reliable measurements. SOD rates were dependent on the method; therefore, care should be taken in comparing SOD data obtained by different methods. There is a need for a carefully researched standardized method for SOD determinations.

Safety in the Chemical Laboratory: Tested Disposal Methods for Chemical Wastes from Academic Laboratories.

ERIC Educational Resources Information Center

Armour, M. A.; And Others

1985-01-01

Describes procedures for disposing of dichromate cleaning solution, picric acid, organic azides, oxalic acid, chemical spills, and hydroperoxides in ethers and alkenes. These methods have been tested under laboratory conditions and are specific for individual chemicals rather than for groups of chemicals. (JN)

[How to Interpret and Use Routine Laboratory Data--Our Methods to Interpret Routine Laboratory Data--Chairmen's Introductory Remarks].

PubMed

Honda, Takayuki; Tozuka, Minoru

2015-09-01

In the reversed clinicopathological conference (R-CPC), three specialists in laboratory medicine interpreted routine laboratory data independently in order to understand the detailed state of a patient. R-CPC is an educational method to use laboratory data appropriately, and it is also important to select differential diagnoses in a process of clinical reasoning in addition to the present illness and physical examination. Routine laboratory tests can be performed repeatedly at a relatively low cost, and their time-series analysis can be performed. Interpretation of routine laboratory data is almost the same as taking physical findings. General findings are initially checked and then the state of each organ is examined. Although routine laboratory tests cost little, we can gain much more information from them about the patient than physical examinations.

Comparison of a New Cobinamide-Based Method to a Standard Laboratory Method for Measuring Cyanide in Human Blood

PubMed Central

Swezey, Robert; Shinn, Walter; Green, Carol; Drover, David R.; Hammer, Gregory B.; Schulman, Scott R.; Zajicek, Anne; Jett, David A.; Boss, Gerry R.

2013-01-01

Most hospital laboratories do not measure blood cyanide concentrations, and samples must be sent to reference laboratories. A simple method is needed for measuring cyanide in hospitals. The authors previously developed a method to quantify cyanide based on the high binding affinity of the vitamin B12 analog, cobinamide, for cyanide and a major spectral change observed for cyanide-bound cobinamide. This method is now validated in human blood, and the findings include a mean inter-assay accuracy of 99.1%, precision of 8.75% and a lower limit of quantification of 3.27 µM cyanide. The method was applied to blood samples from children treated with sodium nitroprusside and it yielded measurable results in 88 of 172 samples (51%), whereas the reference laboratory yielded results in only 19 samples (11%). In all 19 samples, the cobinamide-based method also yielded measurable results. The two methods showed reasonable agreement when analyzed by linear regression, but not when analyzed by a standard error of the estimate or paired t-test. Differences in results between the two methods may be because samples were assayed at different times on different sample types. The cobinamide-based method is applicable to human blood, and can be used in hospital laboratories and emergency rooms. PMID:23653045

Systematic approach to characterisation of NORM in Thailand.

PubMed

Chanyotha, S; Kranrod, C; Pengvanich, P

2015-11-01

The aim of this article is to provide information on the systematic approach that has been developed for the measurement of natural radiation exposure and the characterisation of naturally occurring radioactive materials (NORM) in terms of occurrence and distribution in various industrial processes, including the produced waste from the mineral industries in Thailand. The approach can be adapted for various types of study areas. The importance of collaboration among research institutions is discussed. Some developments include 25 documents; the redesign of the field equipment, such as the gamma survey meter, for convenient access to conduct measurement in various study areas; the method to collect and analyse radon gas from a natural gas pipeline and the manganese dioxide fibre to adsorb radium on-site for laboratory analysis. The NORM project in Thailand has been carried out for more than 10 y to support the development of NORM regulation in Thailand. In the previous studies as well as current, international standards for action levels have been adopted for safety purpose. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

[Research of Odo Bujwid (1857-1942) concerning the vaccine against rabies-historical characterisation].

PubMed

Wasiewicz, Barbara

2016-01-01

The present article refers to the historical characterisation of Odo Bujwid's (1857-1942) research concerning the vaccine against rabies. The introduction refers to the treatment methods applied before Ludwik Pasteur's discovery. The following part refers to Odo Bujwid's own research including diagnostics, characterisation of the symptoms of disease, modification of the original Ludwik Pasteur's method and statistical information. The resume emphasizes that Odo Bujwid's scientific research was the introduction and generalisation the worldwide microbiology knowledge at the polish lands.

Orbitrap mass analyser for in situ characterisation of planetary environments: Performance evaluation of a laboratory prototype

NASA Astrophysics Data System (ADS)

Briois, Christelle; Thissen, Roland; Thirkell, Laurent; Aradj, Kenzi; Bouabdellah, Abdel; Boukrara, Amirouche; Carrasco, Nathalie; Chalumeau, Gilles; Chapelon, Olivier; Colin, Fabrice; Coll, Patrice; Cottin, Hervé; Engrand, Cécile; Grand, Noel; Lebreton, Jean-Pierre; Orthous-Daunay, François-Régis; Pennanech, Cyril; Szopa, Cyril; Vuitton, Véronique; Zapf, Pascal; Makarov, Alexander

2016-10-01

For decades of space exploration, mass spectrometry has proven to be a reliable instrumentation for the characterisation of the nature and energy of ionic and neutral, atomic and molecular species in the interplanetary medium and upper planetary atmospheres. It has been used as well to analyse the chemical composition of planetary and small bodies environments. The chemical complexity of these environments calls for the need to develop a new generation of mass spectrometers with significantly increased mass resolving power. The recently developed OrbitrapTM mass analyser at ultra-high resolution shows promising adaptability to space instrumentation, offering improved performances for in situ measurements. In this article, we report on our project named ;Cosmorbitrap; aiming at demonstrating the adaptability of the Orbitrap technology for in situ space exploration. We present the prototype that was developed in the laboratory for demonstration of both technical feasibility and analytical capabilities. A set of samples containing elements with masses ranging from 9 to 208 u has been used to evaluate the performance of the analyser, in terms of mass resolving power (reaching 474,000 at m/z 9) and ability to discriminate between isobaric interferences, accuracy of mass measurement (below 15 ppm) and determination of relative isotopic abundances (below 5%) of various samples. We observe a good agreement between the results obtained with the prototype and those of a commercial instrument. As the background pressure is a key parameter for in situ exploration of atmosphere planetary bodies, we study the effect of background gas on the performance of the Cosmorbitrap prototype, showing an upper limit for N2 in our set-up at 10-8 mbar. The results demonstrate the strong potential to adapt this technology to space exploration.

Surface geophysical methods for characterising frozen ground in transitional permafrost landscapes

USGS Publications Warehouse

Briggs, Martin A.; Campbell, Seth; Nolan, Jay; Walvoord, Michelle Ann; Ntarlagiannis, Dimitrios; Day-Lewis, Frederick D.; Lane, John W.

2017-01-01

The distribution of shallow frozen ground is paramount to research in cold regions, and is subject to temporal and spatial changes influenced by climate, landscape disturbance and ecosystem succession. Remote sensing from airborne and satellite platforms is increasing our understanding of landscape-scale permafrost distribution, but typically lacks the resolution to characterise finer-scale processes and phenomena, which are better captured by integrated surface geophysical methods. Here, we demonstrate the use of electrical resistivity imaging (ERI), electromagnetic induction (EMI), ground penetrating radar (GPR) and infrared imaging over multiple summer field seasons around the highly dynamic Twelvemile Lake, Yukon Flats, central Alaska, USA. Twelvemile Lake has generally receded in the past 30 yr, allowing permafrost aggradation in the receded margins, resulting in a mosaic of transient frozen ground adjacent to thick, older permafrost outside the original lakebed. ERI and EMI best evaluated the thickness of shallow, thin permafrost aggradation, which was not clear from frost probing or GPR surveys. GPR most precisely estimated the depth of the active layer, which forward electrical resistivity modelling indicated to be a difficult target for electrical methods, but could be more tractable in time-lapse mode. Infrared imaging of freshly dug soil pit walls captured active-layer thermal gradients at unprecedented resolution, which may be useful in calibrating emerging numerical models. GPR and EMI were able to cover landscape scales (several kilometres) efficiently, and new analysis software showcased here yields calibrated EMI data that reveal the complicated distribution of shallow permafrost in a transitional landscape.

DNA decontamination methods for internal quality management in clinical PCR laboratories.

PubMed

Wu, Yingping; Wu, Jianyong; Zhang, Zhihui; Cheng, Chen

2018-03-01

The polymerase chain reaction (PCR) technique, one of the most commonly applied methods in diagnostic and molecular biology, has a frustrating downside: the occurrence of false-positive signals due to contamination. In previous research, various DNA decontamination methods have been developed to overcome this limitation. Unfortunately, the use of random or poorly focused sampling methods for monitoring air and/or object surfaces leads to the incomplete elimination during decontamination procedures. We herein attempted to develop a novel DNA decontamination method (environmental surveillance, including surface and air sampling) and quality management program for clinical molecular diagnostic laboratories (or clinical PCR laboratories). Here, we performed a step-by-step evaluation of current DNA decontamination methods and developed an effective procedure for assessing the presence of decontaminating DNA via PCR analysis. Performing targeted environmental surveillance by sampling, which reached optimal performance over 2 weeks, and the decontamination process had been verified as reliable. Additionally, the process was validated to not affect PCR amplification efficiency based on a comparative study. In this study, effective guidelines for DNA decontamination were developed. The method employed ensured that surface DNA contamination could be effectively identified and eliminated. Furthermore, our study highlighted the importance of overall quality assurance and good clinical laboratory practices for preventing contamination, which are key factors for compliance with regulatory or accreditation requirements. Taken together, we provided the evidence that the presented scheme ranged from troubleshooting to the elimination of surface contamination, could serve as critical foundation for developing regular environmental surveillance guidelines for PCR laboratories. © 2017 Wiley Periodicals, Inc.

DO TIE LABORATORY BASED ASSESSMENT METHODS REALLY PREDICT FIELD EFFECTS?

EPA Science Inventory

Sediment Toxicity Identification and Evaluation (TIE) methods have been developed for both porewaters and whole sediments. These relatively simple laboratory methods are designed to identify specific toxicants or classes of toxicants in sediments; however, the question of whethe...

Seroepidemiology and phylogenetic characterisation of measles virus in Ireland, 2004-2013.

PubMed

O' Riordan, Bernadette; Carr, Michael J; Connell, Jeff; Dunford, Linda; Hall, William W; Hassan, Jaythoon

2014-08-01

Ireland is classified as an area of high measles incidence. A World Health Organisation-European Region strategic plan exists for measles elimination by 2015. To retrospectively investigate measles outbreaks using all patient samples (sera and oral fluid) received for measles laboratory diagnosis and characterise the genetic diversity of circulating measles genotypes in Ireland. 704 cases of acute measles infection as determined by the presence of measles specific IgM in sera and oral fluids were confirmed at the National Virus Reference Laboratory. Measles positive samples (n=116) were examined by genotyping, sequence analysis and phylogenetic characterisation. Three measles outbreaks occurred over the study period: 2004, 2009/2010 and 2011. Measles IgM positivity ranged from 22-29% in outbreak years to 5-10% in the intervening years. Age profile analysis revealed that whereas individuals >10 years accounted for only 8% of cases in the 2004 outbreak, this increased to 33% and 29% in the 2009/2010 and 2011 outbreaks, respectively. The <1 year cohort accounted for 18-20% of cases in all outbreaks. Phylogenetic analysis demonstrated both indigenous transmission and also importation events. Clade D viruses were exclusively found circulating in Ireland, with autochthonous transmission of diverse genotype D4 strains associated with large outbreaks across Europe. More recently, genotype D8 was identified and these were associated with importation events. This study provides a comprehensive genetic analysis of circulating measles genotypes in Ireland and discriminated between indigenous and imported viral strains. Notably, an increase in laboratory-confirmed measles cases in the greater than 10 years of age group was seen over the study period. This information is valuable to inform vaccination strategies with a focus on those populations who remain susceptible to measles infection. Copyright © 2014 Elsevier B.V. All rights reserved.

Electrochemical synthesis, characterisation and phytogenic properties of silver nanoparticles

NASA Astrophysics Data System (ADS)

Singaravelan, R.; Bangaru Sudarsan Alwar, S.

2015-12-01

This work exemplifies a simple and rapid method for the synthesis of silver nanodendrite with a novel electrochemical technique. The antibacterial activity of these silver nanoparticles (Ag NPs) against pathogenic bacteria was investigated along with the routine study of optical and spectral characterisation. The optical properties of the silver nanoparticles were characterised by diffuse reflectance spectroscopy. The optical band gap energy of the electrodeposited Ag NPs was determined from the diffuse reflectance using Kubelka-Munk formula. X-ray diffraction (XRD) studies were carried out to determine the crystalline nature of the silver nanoparticles which confirmed the formation of silver nanocrystals. The XRD pattern revealed that the electrodeposited Ag NPs were in the cubic geometry with dendrite preponderance. The average particle size and the peak broadening were deliberated using Debye-Scherrer equation and lattice strain due to the peak broadening was studied using Williamson-Hall method. Surface morphology of the Ag NPs was characterised by high-resolution scanning electron microscope and the results showed the high degree of aggregation in the particles. The antibacterial activity of the Ag NPs was evaluated and showed unprecedented level antibacterial activity against multidrug resistant strains such as Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumonia and Escherichia coli in combination with Streptomycin.

Laboratory and Self-Report Methods to Assess Reappraisal and Distraction in Youth.

PubMed

Bettis, Alexandra H; Henry, Lauren; Prussien, Kemar V; Vreeland, Allison; Smith, Michele; Adery, Laura H; Compas, Bruce E

2018-06-07

Coping and emotion regulation are central features of risk and resilience in childhood and adolescence, but research on these constructs has relied on different methods of assessment. The current study aimed to bridge the gap between questionnaire and experimental methods of measuring secondary control coping strategies, specifically distraction and cognitive reappraisal, and examine associations with symptoms of anxiety and depression in youth. A community sample of 70 youth (ages 9-15) completed a novel experimental coping and emotion regulation paradigm and self-report measures of coping and emotion regulation and symptoms. Findings indicate that use of distraction and reappraisal during the laboratory paradigm was associated with lower levels of negative emotion during the task. Youth emotion ratings while implementing distraction, but not reappraisal, during the laboratory task were associated with youth self-reported use of secondary control coping in response to family stress. Youth symptoms of anxiety and depression were also significantly positively associated with negative emotion ratings during the laboratory task, and both laboratory task and self-reported coping and emotion regulation accounted for significant variance in symptoms in youth. Both questionnaire and laboratory methods to assess coping and emotion regulation in youth are important for understanding these processes as possible mechanisms of risk and resilience and continued integration of these methods is a priority for future research.

Project-Based Learning in Undergraduate Environmental Chemistry Laboratory: Using EPA Methods to Guide Student Method Development for Pesticide Quantitation

ERIC Educational Resources Information Center

Davis, Eric J.; Pauls, Steve; Dick, Jonathan

2017-01-01

Presented is a project-based learning (PBL) laboratory approach for an upper-division environmental chemistry or quantitative analysis course. In this work, a combined laboratory class of 11 environmental chemistry students developed a method based on published EPA methods for the extraction of dichlorodiphenyltrichloroethane (DDT) and its…

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; arsenic speciation in natural-water samples using laboratory and field methods

USGS Publications Warehouse

Garbarino, John R.; Bednar, Anthony J.; Burkhardt, Mark R.

2002-01-01

Analytical methods for the determination of arsenite [As(III)], arsenate [As(V)], dimethylarsinate (DMA), monomethylarsonate (MMA), and roxarsone in filtered natural-water samples are described. Various analytical methods can be used for the determination, depending on the arsenic species being determined. Arsenic concentration is determined by using inductively coupled plasma-mass spectrometry (ICP-MS) as an arsenic-specific detector for all methods. Laboratory-speciation methods are described that use an ion chromatographic column to separate the arsenic species; the column length, column packing, and mobile phase are dependent on the species of interest. Regardless of the separation technique, the arsenic species are introduced into plasma by eithe rpneumatic nebulization or arsine generation. Analysis times range from 2 to 8 minutes and method detection limits range from 0.1 to 0.6 microgram-arsenic per liter (ug-As/L), 10 to 60 picograms absolute (for a 100-microliter injection), depending on the arsenic species determined and the analytical method used. A field-generation specciation method also is described that uses a strong anion exchange cartridge to separate As(III) from As(V) in the field. As(III) in the eluate and the As(V) in the cartridge extract are determined by direct nebulization ICP-MS. Methylated arsenic species that also are retained on the cartridge will positively bias As(V) results without further laboratory separations. The method detection limit for field speciation is 0.3 ug-As/L. The distribution of arsenic species must be preserved in the field to eliminate changes caused by photochemical oxidation or metal oxyhydroxide precipitation. Preservation techniques, such as refrigeration, the addition of acides, or the additoin of ethylene-diaminetetraacetic acid (EDTA) and the effects of ambient light were tested. Of the preservatives evaluated, EDTA was found to work best with the laboratory- and field-speciation methods for all sample

INTER LABORATORY COMBAT HELMET BLUNT IMPACT TEST METHOD COMPARISON

DTIC Science & Technology

2018-03-26

HELMET BLUNT IMPACT TEST METHOD COMPARISON by Tony J. Kayhart Charles A. Hewitt and Jonathan Cyganik March 2018 Final...Report March 2016 – August 2017 Approved for public release; distribution is unlimited U.S. Army Natick Soldier Research ...INTER-LABORATORY COMBAT HELMET BLUNT IMPACT TEST METHOD COMPARISON 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR

LC-UV assay method and UPLC/Q-TOF-MS characterisation of saponins from Ilex paraguariensis A. St. Hil. (mate) unripe fruits.

PubMed

Peixoto, Maria Paula Garofo; Kaiser, Samuel; Verza, Simone Gasparin; de Resende, Pedro Ernesto; Treter, Janine; Pavei, Cabral; Borré, Gustavo Luís; Ortega, George González

2012-01-01

Ilex paraguariensis A. St. Hil. (mate) is known in several South American countries because of the use of its leaves in stimulant herbal beverages. High saponin contents were reported in mate leaves and unripe fruits that possess a dissimilar composition. Two LC-UV methods previously reported for mate saponins assay focused on mate leaves and the quantification of the less polar saponin fraction in mate fruits. To develop and validate a LC-UV method to assay the total content of saponins in unripe mate fruits and characterise the chemical structure of triterpenic saponins by UPLC/Q-TOF-MS. From unripe fruits of mate a crude ethanolic extract was prepared (EX40) and the mate saponin fraction (MSF) purified by solid phase extraction. The LC-UV method was validated using ilexoside II as external standard. UPLC/Q-TOF-MS was adjusted from the LC-UV method to obtain the fragmentation patterns of the main saponins present in unripe fruits. Both LC-UV and UPLC/Q-TOF-MS methods indicate a wide range of Ilex saponins polarity. The ilexoside II and total saponin content of EX40 were 8.20% (w/w) and 47.60% (w/w), respectively. The total saponin content in unripe fruits was 7.28% (w/w). The saponins present in MSF characterised by UPLC/Q-TOF-MS are derived mainly from ursolic/oleanolic, acetyl ursolic or pomolic acid. The validated LC-UV method was shown to be linear, precise, accurate and to cover several saponins previously isolated from Ilex species and could be applied for the quality control of unripe fruit saponins. Copyright © 2011 John Wiley & Sons, Ltd.

Characterising the disintegration properties of tablets in opaque media using texture analysis.

PubMed

Scheuerle, Rebekah L; Gerrard, Stephen E; Kendall, Richard A; Tuleu, Catherine; Slater, Nigel K H; Mahbubani, Krishnaa T

2015-01-01

Tablet disintegration characterisation is used in pharmaceutical research, development, and quality control. Standard methods used to characterise tablet disintegration are often dependent on visual observation in measurement of disintegration times. This presents a challenge for disintegration studies of tablets in opaque, physiologically relevant media that could be useful for tablet formulation optimisation. This study has explored an application of texture analysis disintegration testing, a non-visual, quantitative means of determining tablet disintegration end point, by analysing the disintegration behaviour of two tablet formulations in opaque media. In this study, the disintegration behaviour of one tablet formulation manufactured in-house, and Sybedia Flashtab placebo tablets in water, bovine, and human milk were characterised. A novel method is presented to characterise the disintegration process and to quantify the disintegration end points of the tablets in various media using load data generated by a texture analyser probe. The disintegration times in the different media were found to be statistically different (P<0.0001) from one another for both tablet formulations using one-way ANOVA. Using the Tukey post-hoc test, the Sybedia Flashtab placebo tablets were found not to have statistically significant disintegration times from each other in human versus bovine milk (adjusted P value 0.1685). Copyright © 2015 Elsevier B.V. All rights reserved.

CESAR: A Code for Nuclear Fuel and Waste Characterisation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vidal, J.M.; Grouiller, J.P.; Launay, A.

2006-07-01

CESAR (Simplified Evolution Code Applied to Reprocessing) is a depletion code developed through a joint program between CEA and COGEMA. In the late 1980's, the first use of this code dealt with nuclear measurement at the Laboratories of the La Hague reprocessing plant. The use of CESAR was then extended to characterizations of all entrance materials and for characterisation, via tracer, of all produced waste. The code can distinguish more than 100 heavy nuclides, 200 fission products and 100 activation products, and it can characterise both the fuel and the structural material of the fuel. CESAR can also make depletionmore » calculations from 3 months to 1 million years of cooling time. Between 2003-2005, the 5. version of the code was developed. The modifications were related to the harmonisation of the code's nuclear data with the JEF2.2 nuclear data file. This paper describes the code and explains the extensive use of this code at the La Hague reprocessing plant and also for prospective studies. The second part focuses on the modifications of the latest version, and describes the application field and the qualification of the code. Many companies and the IAEA use CESAR today. CESAR offers a Graphical User Interface, which is very user-friendly. (authors)« less

Production and physico-chemical characterisation of nanoparticles.

PubMed

Schulze Isfort, C; Rochnia, M

2009-05-08

Synthetic nanoscaled metal oxides are mainly produced by pyrogenic decomposition of precursors in the gas phase using a hot-wall or plasma reactor. Due to their low production rate and limited scalability, these processes are of minor technical relevance in manufacturing commercial quantities of nanoparticles. The most common and by far the most important industrial process is flame hydrolysis. In this process, a gaseous mixture of a metal chloride precursor, hydrogen and air is introduced in a closed and continuously operated flame reactor. The general mechanism of formation and growth of particles (e.g. silica) occurring in the flame is dominated by nucleation, coalescence (sintering) and coagulation (collision) of primary particles forming aggregated structures. The term 'aggregate' describes clusters of particles held together by strong chemical bonds. Agglomerates, however, are defined as loose accumulations of particles held together by hydrogen bonds for example. Although, a variety of physico-chemical methods exist to characterise pyrogenic oxides, the most important ones are analysis of the specific surface area by the so-called BET method, determination of the aggregate size by transmission electron microscopy (TEM) and characterisation of the phase composition by means of X-ray analysis.

New Methods May Reduce Needs, Can't Replace Laboratory Animals

ERIC Educational Resources Information Center

Leeper, E. M.

1976-01-01

Discusses the symposium between the scientific community and the animal welfare community in which the consensus was absolute: new laboratory methods can complement but not replace intact animals. (LS)

Characterisation

DTIC Science & Technology

2007-03-01

Characterisation. In Nanotechnology Aerospace Applications – 2006 (pp. 4-1 – 4-8). Educational Notes RTO-EN-AVT-129bis, Paper 4. Neuilly-sur-Seine, France: RTO...the Commercialisation Processes Concept IDEA Proof-of- Principle Trial Samples Engineering Verification Samples Design Verification Samples...SEIC Systems Engineering for commercialisation Design Houses, Engineering & R&D USERS & Integrators SE S U R Integrators Fabs & Wafer Processing Die

Hot Salsa: A Laboratory Exercise Exploring the Scientific Method.

ERIC Educational Resources Information Center

Levri, Edward P.; Levri, Maureen A.

2003-01-01

Presents a laboratory exercise on spicy food and body temperature that introduces the scientific method to introductory biology students. Suggests that when students perform their own experiments which they have developed, it helps with their understanding of and confidence in doing science. (Author/SOE)

Laboratory Sequence in Computational Methods for Introductory Chemistry

NASA Astrophysics Data System (ADS)

Cody, Jason A.; Wiser, Dawn C.

2003-07-01

A four-exercise laboratory sequence for introductory chemistry integrating hands-on, student-centered experience with computer modeling has been designed and implemented. The progression builds from exploration of molecular shapes to intermolecular forces and the impact of those forces on chemical separations made with gas chromatography and distillation. The sequence ends with an exploration of molecular orbitals. The students use the computers as a tool; they build the molecules, submit the calculations, and interpret the results. Because of the construction of the sequence and its placement spanning the semester break, good laboratory notebook practices are reinforced and the continuity of course content and methods between semesters is emphasized. The inclusion of these techniques in the first year of chemistry has had a positive impact on student perceptions and student learning.

Sensory analysis of characterising flavours: evaluating tobacco product odours using an expert panel.

PubMed

Krüsemann, Erna J Z; Lasschuijt, Marlou P; de Graaf, C; de Wijk, René A; Punter, Pieter H; van Tiel, Loes; Cremers, Johannes W J M; van de Nobelen, Suzanne; Boesveldt, Sanne; Talhout, Reinskje

2018-05-23

Tobacco flavours are an important regulatory concept in several jurisdictions, for example in the USA, Canada and Europe. The European Tobacco Products Directive 2014/40/EU prohibits cigarettes and roll-your-own tobacco having a characterising flavour. This directive defines characterising flavour as 'a clearly noticeable smell or taste other than one of tobacco […]'. To distinguish between products with and without a characterising flavour, we trained an expert panel to identify characterising flavours by smelling. An expert panel (n=18) evaluated the smell of 20 tobacco products using self-defined odour attributes, following Quantitative Descriptive Analysis. The panel was trained during 14 attribute training, consensus training and performance monitoring sessions. Products were assessed during six test sessions. Principal component analysis, hierarchical clustering (four and six clusters) and Hotelling's T-tests (95% and 99% CIs) were used to determine differences and similarities between tobacco products based on odour attributes. The final attribute list contained 13 odour descriptors. Panel performance was sufficient after 14 training sessions. Products marketed as unflavoured that formed a cluster were considered reference products. A four-cluster method distinguished cherry-flavoured, vanilla-flavoured and menthol-flavoured products from reference products. Six clusters subdivided reference products into tobacco leaves, roll-your-own and commercial products. An expert panel was successfully trained to assess characterising odours in cigarettes and roll-your-own tobacco. This method could be applied to other product types such as e-cigarettes. Regulatory decisions on the choice of reference products and significance level are needed which directly influences the products being assessed as having a characterising odour. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use

Microfluidic free-flow electrophoresis for the discovery and characterisation of calmodulin binding partners

NASA Astrophysics Data System (ADS)

Herling, Therese; Linse, Sara; Knowles, Tuomas

2015-03-01

Non-covalent and transient protein-ligand interactions are integral to cellular function and malfunction. Key steps in signalling and regulatory pathways rely on reversible non-covalent protein-protein binding or ion chelation. Here we present a microfluidic free-flow electrophoresis method for detecting and characterising protein-ligand interactions in solution. We apply this method to probe the binding equilibria of calmodulin, a central protein to calcium signalling pathways. In this study we characterise the specific binding of calmodulin to phosphorylase kinase, a known target, and creatine kinase, which we identify as a putative binding partner through a protein array screen and surface plasmon resonance experiments. We verify the interaction between calmodulin and creatine kinase in solution using free-flow electrophoresis and investigate the effect of calcium and sodium chloride on the calmodulin-ligand binding affinity in free solution without the presence of a potentially interfering surface. Our results demonstrate the general applicability of quantitative microfluidic electrophoresis to characterise binding equilibria between biomolecules in solution.

An outbreak of penicillin resistant Streptococcus pneumoniae investigated by a polymerase chain reaction based genotyping method.

PubMed Central

Gillespie, S H; McHugh, T D; Hughes, J E; Dickens, A; Kyi, M S; Kelsey, M

1997-01-01

AIMS: To characterise the genotypes of penicillin resistant Streptococcus pneumoniae infecting patients in a care of the elderly ward and to study its transmission in a hospital environment. METHODS: Isolates of S pneumoniae were cultured from specimens obtained from patients who had been admitted to a care of the elderly ward where an outbreak had occurred. Penicillin resistant S pneumoniae were also obtained from a series of surveillance throat swabs taken from patients in the same ward. In addition, all penicillin resistant S pneumoniae isolated from specimens submitted for culture at the time of the outbreak were included. Four sensitive strains isolated from a routine microbiology laboratory were included as controls. A simple polymerase chain reaction (PCR) based genotyping method for the penicillin binding protein (PBP) genes 1a, 2x, and 2b was used to characterise the genotypes. RESULTS: Nine patients were infected with serotype 9 S pneumoniae. Four of these patients died; two deaths were directly attributable to the infection. Tested against a battery of haemolytic streptococci and other organisms found in the respiratory tract, only two false positive reactions for PBP 2x were found among S mitis. The method demonstrated that the outbreak strain had altered PBP 1a, 2b, and 2x genes, a pattern clearly distinguishable from other penicillin resistant strains isolated at the same time. CONCLUSIONS: This method is simple to perform and would enable many laboratories to characterise the genotype of penicillin resistant S pneumoniae and investigate transmission in their hospitals. Images PMID:9462268

Characterisation of the ecotoxicity of hospital effluents: a review.

PubMed

Orias, Frédéric; Perrodin, Yves

2013-06-01

The multiple activities that take place in hospitals (surgery, drug treatments, radiology, cleaning of premises and linen, chemical and biological analysis laboratories, etc.), are a major source of pollutant emissions into the environment (disinfectants, detergents, drug residues, etc.). Most of these pollutants can be found in hospital effluents (HWW), then in urban sewer networks and WWTP (weakly adapted for their treatment) and finally in aquatic environments. In view to evaluating the impact of these pollutants on aquatic ecosystems, it is necessary to characterise their ecotoxicity. Several reviews have focused on the quantitative and qualitative characterisation of pollutants present in HWW. However, none have focused specifically on the characterisation of their experimental ecotoxicity. We have evaluated this according to two complementary approaches: (i) a "substance" approach based on the identification of the experimental data in the literature for different substances found in hospital effluents, and on the calculation of their PNEC (Predicted Non Effect Concentration), (ii) a "matrix" approach for which we have synthesised ecotoxicity data obtained from the hospital effluents directly. This work first highlights the diversity of the substances present within hospital effluents, and the very high ecotoxicity of some of them (minimum PNEC observed close to 0,01 pg/L). We also observed that the consumption of drugs in hospitals was a predominant factor chosen by authors to prioritise the compounds to be sought. Other criteria such as biodegradability, excretion rate and the bioaccumulability of pollutants are considered, though more rarely. Studies of the ecotoxicity of the particulate phase of effluents must also be taken into account. It is also necessary to monitor the effluents of each of the specialised departments of the hospital studied. These steps is necessary to define realistic environmental management policies for hospitals (replacement of

An Overview of the Computational Physics and Methods Group at Los Alamos National Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, Randal Scott

CCS Division was formed to strengthen the visibility and impact of computer science and computational physics research on strategic directions for the Laboratory. Both computer science and computational science are now central to scientific discovery and innovation. They have become indispensable tools for all other scientific missions at the Laboratory. CCS Division forms a bridge between external partners and Laboratory programs, bringing new ideas and technologies to bear on today’s important problems and attracting high-quality technical staff members to the Laboratory. The Computational Physics and Methods Group CCS-2 conducts methods research and develops scientific software aimed at the latest andmore » emerging HPC systems.« less

Modular workcells: modern methods for laboratory automation.

PubMed

Felder, R A

1998-12-01

Laboratory automation is beginning to become an indispensable survival tool for laboratories facing difficult market competition. However, estimates suggest that only 8% of laboratories will be able to afford total laboratory automation systems. Therefore, automation vendors have developed alternative hardware configurations called 'modular automation', to fit the smaller laboratory. Modular automation consists of consolidated analyzers, integrated analyzers, modular workcells, and pre- and post-analytical automation. These terms will be defined in this paper. Using a modular automation model, the automated core laboratory will become a site where laboratory data is evaluated by trained professionals to provide diagnostic information to practising physicians. Modem software information management and process control tools will complement modular hardware. Proper standardization that will allow vendor-independent modular configurations will assure success of this revolutionary new technology.

Laboratory Validation and Field Assessment of Petroleum Laboratory Technicians' Dermal Exposure to Crude Oil Using a Wipe Sampling Method.

PubMed

Galea, Karen S; Mueller, Will; Arfaj, Ayman M; Llamas, Jose L; Buick, Jennifer; Todd, David; McGonagle, Carolyn

2018-05-21

Crude oil may cause adverse dermal effects therefore dermal exposure is an exposure route of concern. Galea et al. (2014b) reported on a study comparing recovery (wipe) and interception (cotton glove) dermal sampling methods. The authors concluded that both methods were suitable for assessing dermal exposure to oil-based drilling fluids and crude oil but that glove samplers may overestimate the amount of fluid transferred to the skin. We describe a study which aimed to further evaluate the wipe sampling method to assess dermal exposure to crude oil, with this assessment including extended sample storage periods and sampling efficiency tests being undertaken at environmental conditions to mimic those typical of outdoor conditions in Saudi Arabia. The wipe sampling method was then used to assess the laboratory technicians' actual exposure to crude oil during typical petroleum laboratory tasks. Overall, acceptable storage efficiencies up to 54 days were reported with results suggesting storage stability over time. Sampling efficiencies were also reported to be satisfactory at both ambient and elevated temperature and relative humidity environmental conditions for surrogate skin spiked with known masses of crude oil and left up to 4 h prior to wiping, though there was an indication of reduced sampling efficiency over time. Nineteen petroleum laboratory technicians provided a total of 35 pre- and 35 post-activity paired hand wipe samples. Ninety-three percent of the pre-exposure paired hand wipes were less than the analytical limit of detection (LOD), whereas 46% of the post-activity paired hand wipes were less than the LOD. The geometric mean paired post-activity wipe sample measurement was 3.09 µg cm-2 (range 1.76-35.4 µg cm-2). It was considered that dermal exposure most frequently occurred through direct contact with the crude oil (emission) or via deposition. The findings of this study suggest that the wipe sampling method is satisfactory in quantifying

Assessment of electrochemical properties of a biogalvanic system for tissue characterisation

PubMed Central

Chandler, J.H.; Culmer, P.R.; Jayne, D.G.; Neville, A.

2015-01-01

Biogalvanic characterisation is a promising method for obtaining health-specific tissue information. However, there is a dearth of understanding in the literature regarding the underlying galvanic cell, electrode reactions and their controlling factors which limits the application of the technique. This work presents a parametric electrochemical investigation into a zinc–copper galvanic system using salt (NaCl) solution analogues at physiologically-relevant concentrations (1.71, 17.1 & 154 mM). The potential difference at open cell, closed cell maximum current and the internal resistance (based on published characterisation methods) were measured. Additionally, independent and relative polarisation scans of the electrodes were performed to improve understanding of the system. Our findings suggest that the prominent reaction at the cathode is that of oxygen-reduction, not hydrogen-evolution. Results indicate that cell potentials are influenced by the concentration of dissolved oxygen at low currents and maximum closed cell currents are limited by the rate of oxygen diffusion to the cathode. Characterised internal resistance values for the salt solutions did not correspond to theoretical values at the extremes of concentration (1.71 and 154 mM) due to electrode resistance and current limitation. Existing biogalvanic models do not consider these phenomena and should be improved to advance the technique and its practical application. PMID:25460609

[Laboratory diagnosis of genital herpes--direct immunofluorescence method].

PubMed

Majewska, Anna; Romejko-Wolniewicz, Ewa; Zareba-Szczudlik, Julia; Kilijańczyk, Marek; Gajewska, Małgorzata; Młynarczyk, Grazyna

2013-07-01

Aim of the study was to determine clinical usefulness of direct immunofluorescence method in the laboratory diagnosis of genital herpes in women. Overall 187 anogenital swabs were collected from 120 women. Using a dacron-tipped applicator 83 swabs were collected from women suspected of genital herpes and 104 from patients with no signs of genital infection. All samples were tested using cell culture (Vero cell line) and then direct immunofluorescence method (DIF) for the identification of antigens of herpes simplex viruses: HSV-1 and HSV-2. Characteristic cytopathic effect (CPE), indicative of alphaherpesvirus infection, was observed in 43.4% of cultures with clinical specimens collected from women with suspected genital herpes and in 29.8% of cultures of clinical specimens taken from patients with no clinical symptoms of genital herpes. Herpes simplex viruses were determined in 73 samples by direct immunofluorescence method after amplification of the virus in cell culture. The DIF test confirmed the diagnosis based on the microscopic CPE observation in 85%. In 15% of samples (taken from pregnant women without clinical signs of infection) we reported positive immunofluorescence in the absence of CPE. The frequency of antigen detection was statistically significantly higher in samples that were positive by culture study (chi-square test with Yates's correction, p < 0.01). This method proved to be highly sensitive (97%) in women with clinically suspected infection. High negative predictive value (99%) proves the clinical utility of the DIF in these group of patients. In asymptomatic infections, viral antigens were detected most frequently in the swabs from the cervical canal, and in cases of suspected genital herpes in swabs taken from the vestibule of the vagina and the vulva. However, there was no statistically significant difference in the frequency of detection of Herpes Simplex Virus antigens in specimens from different parts of the genital tract in both groups

Use of the Raman spectrometer in gemmological laboratories: Review

NASA Astrophysics Data System (ADS)

Kiefert, Lore; Karampelas, Stefanos

2011-10-01

The current paper gives an overview of the development of Raman spectrometry in gemmological laboratories. While before 1990s, no commercial gemmological laboratory possessed such an instrument, all larger international labs have acquired these instruments by now. The Raman spectrometer is routinely used for the detection of emerald fillers, HPHT treatment of diamonds, analysis of the nature of a gemstone, analysis of gemstone inclusions and treatments, and the characterisation of natural or colour enhanced pearls and corals. Future developments in gemstone research lie in the closer analysis of the features of Raman and PL spectra and in the combination of several instruments.

The nano-epsilon dot method for strain rate viscoelastic characterisation of soft biomaterials by spherical nano-indentation.

PubMed

Mattei, G; Gruca, G; Rijnveld, N; Ahluwalia, A

2015-10-01

Nano-indentation is widely used for probing the micromechanical properties of materials. Based on the indentation of surfaces using probes with a well-defined geometry, the elastic and viscoelastic constants of materials can be determined by relating indenter geometry and measured load and displacement to parameters which represent stress and deformation. Here we describe a method to derive the viscoelastic properties of soft hydrated materials at the micro-scale using constant strain rates and stress-free initial conditions. Using a new self-consistent definition of indentation stress and strain and corresponding unique depth-independent expression for indentation strain rate, the epsilon dot method, which is suitable for bulk compression testing, is transformed to nano-indentation. We demonstrate how two materials can be tested with a displacement controlled commercial nano-indentor using the nano-espilon dot method (nano-ε̇M) to give values of instantaneous and equilibrium elastic moduli and time constants with high precision. As samples are tested in stress-free initial conditions, the nano-ε̇M could be useful for characterising the micro-mechanical behaviour of soft materials such as hydrogels and biological tissues at cell length scales. Copyright © 2015 Elsevier Ltd. All rights reserved.

A RP-HPLC-DAD-APCI/MSD method for the characterisation of medicinal Ericaceae used by the Eeyou Istchee Cree First Nations.

PubMed

Saleem, Ammar; Harris, Cory S; Asim, Muhammad; Cuerrier, Alain; Martineau, Louis; Haddad, Pierre S; Arnason, John T

2010-01-01

Ericaceae medicinal plants are traditionally used by the Eeyou Istchee Cree and other northern peoples of North America to treat type 2 diabetic symptoms. Because of the importance of phenolics as potential cures for degenerative diseases including type 2 diabetes, an analytical method was developed to detect them in the leaf extracts of 14 Ericaceae plants. To develop an optimised method which is applicable to a relatively large number of Ericaceae plants using their leaf extracts. For this purpose phenolics with a wide range of polarity, including a glucosylated benzoquinone, two phenolic acids, three flavanols, a flavanone, a flavone and five flavonols, were included in this study. Characterisation of phytochemicals in extracts was undertaken by automated matching to the UV spectra to those of an in house library of plant secondary metabolites and the authentication of their identity was achieved by reversed phase-high-performance chromatography-diode array detection-atmospheric pressure chemical ionisation/mass selective detection. Twenty-six phenolics were characterised within 26 min of chromatographic separation in 80% ethanol extracts of 14 Ericaceae plants. The calibration curves were linear within 0.5-880 microg/g dry mass of the plant with regression values better than 0.995. The limits of detection ranged from 0.3 for microg/mL for (+)-catechin to 2.6 microg/mL for chlorogenic acid. This is a first study dealing with relatively large number of Ericaceae extracts and is applicable to other plants of same family.

Characterising switching behaviour in perceptual multi-stability.

PubMed

Denham, Susan; Bendixen, Alexandra; Mill, Robert; Tóth, Dénes; Wennekers, Thomas; Coath, Martin; Bőhm, Tamás; Szalardy, Orsolya; Winkler, István

2012-09-15

When people experience an unchanging sensory input for a long period of time, their perception tends to switch stochastically and unavoidably between alternative interpretations of the sensation; a phenomenon known as perceptual bi-stability or multi-stability. The huge variability in the experimental data obtained in such paradigms makes it difficult to distinguish typical patterns of behaviour, or to identify differences between switching patterns. Here we propose a new approach to characterising switching behaviour based upon the extraction of transition matrices from the data, which provide a compact representation that is well-understood mathematically. On the basis of this representation we can characterise patterns of perceptual switching, visualise and simulate typical switching patterns, and calculate the likelihood of observing a particular switching pattern. The proposed method can support comparisons between different observers, experimental conditions and even experiments. We demonstrate the insights offered by this approach using examples from our experiments investigating multi-stability in auditory streaming. However, the methodology is generic and thus widely applicable in studies of multi-stability in any domain. Copyright © 2012 Elsevier B.V. All rights reserved.

Mechanical characterisation of agarose-based chromatography resins for biopharmaceutical manufacture.

PubMed

Nweke, Mauryn C; McCartney, R Graham; Bracewell, Daniel G

2017-12-29

Mechanical characterisation of agarose-based resins is an important factor in ensuring robust chromatographic performance in the manufacture of biopharmaceuticals. Pressure-flow profiles are most commonly used to characterise these properties. There are a number of drawbacks with this method, including the potential need for several re-packs to achieve the desired packing quality, the impact of wall effects on experimental set up and the quantities of chromatography media and buffers required. To address these issues, we have developed a dynamic mechanical analysis (DMA) technique that characterises the mechanical properties of resins based on the viscoelasticity of a 1ml sample of slurry. This technique was conducted on seven resins with varying degrees of mechanical robustness and the results were compared to pressure-flow test results on the same resins. Results show a strong correlation between the two techniques. The most mechanically robust resin (Capto Q) had a critical velocity 3.3 times higher than the weakest (Sepharose CL-4B), whilst the DMA technique showed Capto Q to have a slurry deformation rate 8.3 times lower than Sepharose CL-4B. To ascertain whether polymer structure is indicative of mechanical strength, scanning electron microscopy images were also used to study the structural properties of each resin. Results indicate that DMA can be used as a small volume, complementary technique for the mechanical characterisation of chromatography media. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Evaluating Point of Sale Tobacco Marketing Using Behavioral Laboratory Methods

PubMed Central

Robinson, Jason D.; Drobes, David J.; Brandon, Thomas H.; Wetter, David W.; Cinciripini, Paul M.

2018-01-01

With passage of the 2009 Family Smoking Prevention and Tobacco Control Act, the FDA has authority to regulate tobacco advertising. As bans on traditional advertising venues and promotion of tobacco products have grown, a greater emphasis has been placed on brand exposure and price promotion in displays of products at the point-of-sale (POS). POS marketing seeks to influence attitudes and behavior towards tobacco products using a variety of explicit and implicit messaging approaches. Behavioral laboratory methods have the potential to provide the FDA with a strong scientific base for regulatory actions and a model for testing future manipulations of POS advertisements. We review aspects of POS marketing that potentially influence smoking behavior, including branding, price promotions, health claims, the marketing of emerging tobacco products, and tobacco counter-advertising. We conceptualize how POS marketing potentially influence individual attention, memory, implicit attitudes, and smoking behavior. Finally, we describe specific behavioral laboratory methods that can be adapted to measure the impact of POS marketing on these domains.

Comparison of on-site field measured inorganic arsenic in rice with laboratory measurements using a field deployable method: Method validation.

PubMed

Mlangeni, Angstone Thembachako; Vecchi, Valeria; Norton, Gareth J; Raab, Andrea; Krupp, Eva M; Feldmann, Joerg

2018-10-15

A commercial arsenic field kit designed to measure inorganic arsenic (iAs) in water was modified into a field deployable method (FDM) to measure iAs in rice. While the method has been validated to give precise and accurate results in the laboratory, its on-site field performance has not been evaluated. This study was designed to test the method on-site in Malawi in order to evaluate its accuracy and precision in determination of iAs on-site by comparing with a validated reference method and giving original data on inorganic arsenic in Malawian rice and rice-based products. The method was validated by using the established laboratory-based HPLC-ICPMS. Statistical tests indicated there were no significant differences between on-site and laboratory iAs measurements determined using the FDM (p = 0.263, ά = 0.05) and between on-site measurements and measurements determined using HPLC-ICP-MS (p = 0.299, ά = 0.05). This method allows quick (within 1 h) and efficient screening of rice containing iAs concentrations on-site. Copyright © 2018 Elsevier Ltd. All rights reserved.

New Laboratory Methods for Characterizing the Immersion Factors for Irradiance

NASA Technical Reports Server (NTRS)

Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Zibordi, Giuseppe; DAlimonte, Davide; vaderLinde, Dirk; Brown, James W.

2003-01-01

The experimental determination of the immersion factor, I(sub f)(lambda), of irradiance collectors is a requirement of any in-water radiometer. The eighth SeaWiFS Intercalibration Round-Robin Experiment (SIRREX-8) showed different implementations, at different laboratories, of the same I(sub f)(lambda) measurement protocol. The different implementations make use of different setups, volumes, and water types. Consequently, they exhibit different accuracies and require different execution times for characterizing an irradiance sensor. In view of standardizing the characterization of I(sub f)(lambda) values for in-water radiometers, together with an increase in the accuracy of methods and a decrease in the execution time, alternative methods are presented, and assessed versus the traditional method. The proposed new laboratory methods include: a) the continuous method, in which optical measurements taken with discrete water depths are substituted by continuous profiles created by removing the water from the water vessel at a constant flow rate (which significantly reduces the time required for the characterization of a single radiometer); and b) the Compact Portable Advanced Characterization Tank (ComPACT) method, in which the commonly used large tanks are replaced by a small water vessel, thereby allowing the determination of I(sub f)(lambda) values with a small water volume, and more importantly, permitting I(sub f)(lambda) characterizations with pure water. Intercomparisons between the continuous and the traditional method showed results within the variance of I(sub f) (lambda) determinations. The use of the continuous method, however, showed a much shorter realization time. Intercomparisons between the ComPACT and the traditional method showed generally higher I(sub f)(lambda) values for the former. This is in agreement with the generalized expectations of a reduction in scattering effects, because of the use of pure water with the ComPACT method versus the use of

Validation of a Laboratory Method for Evaluating Dynamic Properties of Reconstructed Equine Racetrack Surfaces

PubMed Central

Setterbo, Jacob J.; Chau, Anh; Fyhrie, Patricia B.; Hubbard, Mont; Upadhyaya, Shrini K.; Symons, Jennifer E.; Stover, Susan M.

2012-01-01

Background Racetrack surface is a risk factor for racehorse injuries and fatalities. Current research indicates that race surface mechanical properties may be influenced by material composition, moisture content, temperature, and maintenance. Race surface mechanical testing in a controlled laboratory setting would allow for objective evaluation of dynamic properties of surface and factors that affect surface behavior. Objective To develop a method for reconstruction of race surfaces in the laboratory and validate the method by comparison with racetrack measurements of dynamic surface properties. Methods Track-testing device (TTD) impact tests were conducted to simulate equine hoof impact on dirt and synthetic race surfaces; tests were performed both in situ (racetrack) and using laboratory reconstructions of harvested surface materials. Clegg Hammer in situ measurements were used to guide surface reconstruction in the laboratory. Dynamic surface properties were compared between in situ and laboratory settings. Relationships between racetrack TTD and Clegg Hammer measurements were analyzed using stepwise multiple linear regression. Results Most dynamic surface property setting differences (racetrack-laboratory) were small relative to surface material type differences (dirt-synthetic). Clegg Hammer measurements were more strongly correlated with TTD measurements on the synthetic surface than the dirt surface. On the dirt surface, Clegg Hammer decelerations were negatively correlated with TTD forces. Conclusions Laboratory reconstruction of racetrack surfaces guided by Clegg Hammer measurements yielded TTD impact measurements similar to in situ values. The negative correlation between TTD and Clegg Hammer measurements confirms the importance of instrument mass when drawing conclusions from testing results. Lighter impact devices may be less appropriate for assessing dynamic surface properties compared to testing equipment designed to simulate hoof impact (TTD

A method for addressing differences in concentrations of fipronil and three degradates obtained by two different laboratory methods

USGS Publications Warehouse

Crawford, Charles G.; Martin, Jeffrey D.

2017-07-21

In October 2012, the U.S. Geological Survey (USGS) began measuring the concentration of the pesticide fipronil and three of its degradates (desulfinylfipronil, fipronil sulfide, and fipronil sulfone) by a new laboratory method using direct aqueous-injection liquid chromatography tandem mass spectrometry (DAI LC–MS/MS). This method replaced the previous method—in use since 2002—that used gas chromatography/mass spectrometry (GC/MS). The performance of the two methods is not comparable for fipronil and the three degradates. Concentrations of these four chemical compounds determined by the DAI LC–MS/MS method are substantially lower than the GC/MS method. A method was developed to correct for the difference in concentrations obtained by the two laboratory methods based on a methods comparison field study done in 2012. Environmental and field matrix spike samples to be analyzed by both methods from 48 stream sites from across the United States were sampled approximately three times each for this study. These data were used to develop a relation between the two laboratory methods for each compound using regression analysis. The relations were used to calibrate data obtained by the older method to the new method in order to remove any biases attributable to differences in the methods. The coefficients of the equations obtained from the regressions were used to calibrate over 16,600 observations of fipronil, as well as the three degradates determined by the GC/MS method retrieved from the USGS National Water Information System. The calibrated values were then compared to over 7,800 observations of fipronil and to the three degradates determined by the DAI LC–MS/MS method also retrieved from the National Water Information System. The original and calibrated values from the GC/MS method, along with measures of uncertainty in the calibrated values and the original values from the DAI LC–MS/MS method, are provided in an accompanying data release.

Geophysical characterisation of the groundwater-surface water interface

NASA Astrophysics Data System (ADS)

McLachlan, P. J.; Chambers, J. E.; Uhlemann, S. S.; Binley, A.

2017-11-01

Interactions between groundwater (GW) and surface water (SW) have important implications for water quantity, water quality, and ecological health. The subsurface region proximal to SW bodies, the GW-SW interface, is crucial as it actively regulates the transfer of nutrients, contaminants, and water between GW systems and SW environments. However, geological, hydrological, and biogeochemical heterogeneity in the GW-SW interface makes it difficult to characterise with direct observations. Over the past two decades geophysics has been increasingly used to characterise spatial and temporal variability throughout the GW-SW interface. Geophysics is a powerful tool in evaluating structural heterogeneity, revealing zones of GW discharge, and monitoring hydrological processes. Geophysics should be used alongside traditional hydrological and biogeochemical methods to provide additional information about the subsurface. Further integration of commonly used geophysical techniques, and adoption of emerging techniques, has the potential to improve understanding of the properties and processes of the GW-SW interface, and ultimately the implications for water quality and environmental health.

Characterising human atherosclerotic carotid plaque tissue composition and morphology using combined spectroscopic and imaging modalities.

PubMed

Barrett, Hilary E; Mulvihill, John J; Cunnane, Eoghan M; Walsh, Michael T

2015-01-01

Calcification is a marked pathological component in carotid artery plaque. Studies have suggested that calcification may induce regions of high stress concentrations therefore increasing the potential for rupture. However, the mechanical behaviour of the plaque under the influence of calcification is not fully understood. A method of accurately characterising the calcification coupled with the associated mechanical plaque properties is needed to better understand the impact of calcification on the mechanical behaviour of the plaque during minimally invasive treatments. This study proposes a comparison of biochemical and structural characterisation methods of the calcification in carotid plaque specimens to identify plaque mechanical behaviour. Biochemical analysis, by Fourier Transform Infrared (FTIR) spectroscopy, was used to identify the key components, including calcification, in each plaque sample. However, FTIR has a finite penetration depth which may limit the accuracy of the calcification measurement. Therefore, this FTIR analysis was coupled with the identification of the calcification inclusions located internally in the plaque specimen using micro x-ray computed tomography (μX-CT) which measures the calcification volume fraction (CVF) to total tissue content. The tissue characterisation processes were then applied to the mechanical material plaque properties acquired from experimental circumferential loading of human carotid plaque specimen for comparison of the methods. FTIR characterised the degree of plaque progression by identifying the functional groups associated with lipid, collagen and calcification in each specimen. This identified a negative relationship between stiffness and 'lipid to collagen' and 'calcification to collagen' ratios. However, μX-CT results suggest that CVF measurements relate to overall mechanical stiffness, while peak circumferential strength values may be dependent on specific calcification geometries. This study

Physico-chemical properties of manufactured nanomaterials - Characterisation and relevant methods. An outlook based on the OECD Testing Programme.

PubMed

Rasmussen, Kirsten; Rauscher, Hubert; Mech, Agnieszka; Riego Sintes, Juan; Gilliland, Douglas; González, Mar; Kearns, Peter; Moss, Kenneth; Visser, Maaike; Groenewold, Monique; Bleeker, Eric A J

2018-02-01

Identifying and characterising nanomaterials require additional information on physico-chemical properties and test methods, compared to chemicals in general. Furthermore, regulatory decisions for chemicals are usually based upon certain toxicological properties, and these effects may not be equivalent to those for nanomaterials. However, regulatory agencies lack an authoritative decision framework for nanomaterials that links the relevance of certain physico-chemical endpoints to toxicological effects. This paper investigates various physico-chemical endpoints and available test methods that could be used to produce such a decision framework for nanomaterials. It presents an overview of regulatory relevance and methods used for testing fifteen proposed physico-chemical properties of eleven nanomaterials in the OECD Working Party on Manufactured Nanomaterials' Testing Programme, complemented with methods from literature, and assesses the methods' adequacy and applications limits. Most endpoints are of regulatory relevance, though the specific parameters depend on the nanomaterial and type of assessment. Size (distribution) is the common characteristic of all nanomaterials and is decisive information for classifying a material as a nanomaterial. Shape is an important particle descriptor. The octanol-water partitioning coefficient is undefined for particulate nanomaterials. Methods, including sample preparation, need to be further standardised, and some new methods are needed. The current work of OECD's Test Guidelines Programme regarding physico-chemical properties is highlighted. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Validation of laboratory-scale recycling test method of paper PSA label products

Treesearch

Carl Houtman; Karen Scallon; Richard Oldack

2008-01-01

Starting with test methods and a specification developed by the U.S. Postal Service (USPS) Environmentally Benign Pressure Sensitive Adhesive Postage Stamp Program, a laboratory-scale test method and a specification were developed and validated for pressure-sensitive adhesive labels, By comparing results from this new test method and pilot-scale tests, which have been...

Student Reciprocal Peer Teaching as a Method for Active Learning: An Experience in an Electrotechnical Laboratory

NASA Astrophysics Data System (ADS)

Muñoz-García, Miguel A.; Moreda, Guillermo P.; Hernández-Sánchez, Natalia; Valiño, Vanesa

2013-10-01

Active learning is one of the most efficient mechanisms for learning, according to the psychology of learning. When students act as teachers for other students, the communication is more fluent and knowledge is transferred easier than in a traditional classroom. This teaching method is referred to in the literature as reciprocal peer teaching. In this study, the method is applied to laboratory sessions of a higher education institution course, and the students who act as teachers are referred to as "laboratory monitors." A particular way to select the monitors and its impact in the final marks is proposed. A total of 181 students participated in the experiment, experiences with laboratory monitors are discussed, and methods for motivating and training laboratory monitors and regular students are proposed. The types of laboratory sessions that can be led by classmates are discussed. This work is related to the changes in teaching methods in the Spanish higher education system, prompted by the Bologna Process for the construction of the European Higher Education Area

PRN 96-1: Tolerance Enforcement Methods - Independent Laboratory Validation by Petitioner

EPA Pesticide Factsheets

This notice is intended to clarify the requirements for submission of an Independent Laboratory Validation to accompany new pesticide analytical methods and does not contain additional data requirements.This notice supersedes PR Notice 88-5.

Tissue signature characterisation of diffusion tensor abnormalities in cerebral gliomas.

PubMed

Price, Stephen J; Peña, Alonso; Burnet, Neil G; Jena, Raj; Green, Hadrian A L; Carpenter, T Adrian; Pickard, John D; Gillard, Jonathan H

2004-10-01

The inherent invasiveness of malignant cells is a major determinant of the poor prognosis of cerebral gliomas. Diffusion tensor MRI (DTI) can identify white matter abnormalities in gliomas that are not seen on conventional imaging. By breaking down DTI into its isotropic (p) and anisotropic (q) components, we can determine tissue diffusion "signatures". In this study we have characterised these abnormalities in peritumoural white matter tracts. Thirty-five patients with cerebral gliomas and seven normal volunteers were imaged with DTI and T2-weighted sequences at 3 T. Displaced, infiltrated and disrupted white matter tracts were identified using fractional anisotropy (FA) maps and directionally encoded colour maps and characterised using tissue signatures. The diffusion tissue signatures were normal in ROIs where the white matter was displaced. Infiltrated white matter was characterised by an increase in the isotropic component of the tensor (p) and a less marked reduction of the anisotropic component (q). In disrupted white matter tracts, there was a marked reduction in q and increase in p. The direction of water diffusion was grossly abnormal in these cases. Diffusion tissue signatures may be a useful method of assessing occult white matter infiltration. Copyright 2004 Springer-Verlag

LABORATORY EVALUATION OF METHODS TO SEPARATE FINE GRAINED SEDIMENT FROM STORM WATER

EPA Science Inventory

A literature survey had been conducted by the St. Anthony Falls Hydraulic laboratory to assess various methods for separation of sediment from storm water at construction sites. Two methods have shown some promise in this application, and a research program was initiated with the...

SMART characterisation of New Zealand's aquifers using fast and passive methods

NASA Astrophysics Data System (ADS)

Klug, H.; Daughney, C.; Verhagen, F.; Westerhoff, R.; Ward, N. Dudley

2012-04-01

Groundwater resources account for about half of New Zealand's abstractive water needs and supplies about eighty per cent of all water used in the agricultural sector. Despite the importance of New Zealand's groundwater resources, we still lack essential information related to their basic properties such as volume, hydraulic properties, interaction with surface water, and water age. These measures are required to ensure sustainable management in order to avoid overexploitation of water resources and to circumvent water scarcity situations where humans and the economy will be stressed due to insufficient water supply. A newly established research collaboration between New Zealand and Europe aims to provide a methodological framework to characterise New Zealand's groundwater aquifers. The SMART project (www.smart-project.info) will rely on existing data sources of regional councils and research institutes and will develop novel measurement techniques that can be applied to large areas with little effort, little acquisition time, and minimal cost. The project aims to synthesise in situ measurements from sensor observation services, ambient noise seismic tomography, real-time fibre optic temperature sensing, novel age tracers, airborne geophysical surveying and satellite remote sensing techniques. Validation of direct and indirect groundwater information will be achieved through use of multiple methods in case study areas and by "ground-truthing" the new methods against existing data obtained from traditional methods (e.g. drilling, aquifer pump testing, river gauging). An important overarching part of the project is the quantification of uncertainty associated with all techniques to be employed. An online Sensor WebGIS prototype will provide the project results and other case study observations (e.g. temperature, precipitation, soil moisture) in as near real-time as possible. These datasets serve as a validation source for the satellite monitoring results and present

Design and Characterisation of Metallic Glassy Alloys of High Neutron Shielding Capability

NASA Astrophysics Data System (ADS)

Khong, J. C.; Daisenberger, D.; Burca, G.; Kockelmann, W.; Tremsin, A. S.; Mi, J.

2016-11-01

This paper reports the design, making and characterisation of a series of Fe-based bulk metallic glass alloys with the aim of achieving the combined properties of high neutron absorption capability and sufficient glass forming ability. Synchrotron X-ray diffraction and pair distribution function methods were used to characterise the crystalline or amorphous states of the samples. Neutron transmission and macroscopic attenuation coefficients of the designed alloys were measured using energy resolved neutron imaging method and the very recently developed microchannel plate detector. The study found that the newly designed alloy (Fe48Cr15Mo14C15B6Gd2 with a glass forming ability of Ø5.8 mm) has the highest neutron absorption capability among all Fe-based bulk metallic glasses so far reported. It is a promising material for neutron shielding applications.

Design and Characterisation of Metallic Glassy Alloys of High Neutron Shielding Capability.

PubMed

Khong, J C; Daisenberger, D; Burca, G; Kockelmann, W; Tremsin, A S; Mi, J

2016-11-16

This paper reports the design, making and characterisation of a series of Fe-based bulk metallic glass alloys with the aim of achieving the combined properties of high neutron absorption capability and sufficient glass forming ability. Synchrotron X-ray diffraction and pair distribution function methods were used to characterise the crystalline or amorphous states of the samples. Neutron transmission and macroscopic attenuation coefficients of the designed alloys were measured using energy resolved neutron imaging method and the very recently developed microchannel plate detector. The study found that the newly designed alloy (Fe 48 Cr 15 Mo 14 C 15 B 6 Gd 2 with a glass forming ability of Ø5.8 mm) has the highest neutron absorption capability among all Fe-based bulk metallic glasses so far reported. It is a promising material for neutron shielding applications.

Design and Characterisation of Metallic Glassy Alloys of High Neutron Shielding Capability

PubMed Central

Khong, J. C.; Daisenberger, D.; Burca, G.; Kockelmann, W.; Tremsin, A. S.; Mi, J.

2016-01-01

This paper reports the design, making and characterisation of a series of Fe-based bulk metallic glass alloys with the aim of achieving the combined properties of high neutron absorption capability and sufficient glass forming ability. Synchrotron X-ray diffraction and pair distribution function methods were used to characterise the crystalline or amorphous states of the samples. Neutron transmission and macroscopic attenuation coefficients of the designed alloys were measured using energy resolved neutron imaging method and the very recently developed microchannel plate detector. The study found that the newly designed alloy (Fe48Cr15Mo14C15B6Gd2 with a glass forming ability of Ø5.8 mm) has the highest neutron absorption capability among all Fe-based bulk metallic glasses so far reported. It is a promising material for neutron shielding applications. PMID:27848991

Characterisation of longitudinal variation in photonic crystal fibre

NASA Astrophysics Data System (ADS)

Francis-Jones, Robert J. A.; Mosley, Peter J.

2016-10-01

We present a method by which the degree of longitudinal variation in photonic crystal fibre (PCF) may be characterised through seeded four-wave mixing (FWM). Using an iterative numerical reconstruction, we created a model PCF that displays similar FWM phasematching properties across all measured length scales. Our results demonstrate that the structure of our PCF varies by less than 1% and that the characteristic length of the variations is approximately 15 cm.

Attribution and Characterisation of Sclerophyll Forested Landscapes Over Large Areas

NASA Astrophysics Data System (ADS)

Jones, Simon; Soto-Berelov, Mariela; Suarez, Lola; Wilkes, Phil; Woodgate, Will; Haywood, Andrew

2016-06-01

conducted a total of 67 ground-based method-to-method pairwise comparisons across 11 plots in five sites, incorporating the previously mentioned LAI methods. Out of the 67 comparisons, 29 had an RMSE ≥ 0.5 LAIe. This has important implications for the validation of remotely sensed products since ground based techniques themselves exhibit LAI variations greater than internationally recommended guidelines for satellite product accuracies. 2. Two methods of canopy height derivation are proposed and tested over a large area (4 Million Ha). 99th percentile maximum height achieved a RMSE of 6.6%, whilst 95th percentile dominant height a RMSE = 10.3%. Vertical canopy complexity (i.e. the number of forest layers of strata) was calculated as the local maxima of vegetation density within the LiDAR canopy profile and determined using a cubic spline smoothing of Pgap. This was then validated against in-situ and LiDAR observations of canopy strata with an RMSE 0.39 canopy layers. 3. Preliminary results are presented of landcover characterisation using LandTrendr analysis of Landsat LEDAPS data. kNN is then used to link these features to a dense network of 800 field plots sites.

Mechanical DT and NDT: characterisation of building stones and research of correlation for in situ analysis of ancient masonries

NASA Astrophysics Data System (ADS)

Vasanelli, E.; Calia, A.; Aiello, M. A.; Sileo, M.; Leucci, G.

2012-04-01

Restoration works of the historical-architectural built heritage move from the typological and mechanical qualification of the buildings. Minimum destructive impact is required in preliminary diagnostic studies for the interventions, as it is possible. The use of the undestructive and non-invasive diagnostic techniques has always advantages in the activities on pre-existing buildings, in terms of sustainability; moreover, it is a need with respect to the conservation constraints when we act on the historical-architectural heritage. This work deals with destructive and non-destructive tests for the mechanical characterisation of some traditional soft stones, used as building materials in the Southern Italy; it is a part of a larger activity devoted to set up non-invasive diagnostic procedures for the mechanical analysis and qualification of ancient masonries. The laboratory experimental activity is based on the use of mechanical compressive tests, ultrasonic and Schmidt-Hammer tests, and the research of correlation between the results obtained by these crossed tests. It is aimed to verify the effectiveness and/or to point out critical aspects and limits of the above mentioned non-destructive tests - already applied in the field of the concrete and compact stones - with reference to the characterisation of the soft stones. The research of correlations between the results of destructive and non destructive tests has the final aim to reduce the use of destructive analyses on the masonries, by acquiring substitutive information derivable from performing NDT in laboratory, as well as in situ conditions. Finally, data gathered by the mechanical characterisation give reference values for the evaluation and control of the effectiveness of restoration interventions and their monitoring. This activity is carried out in an interdisciplinary way within the AITECH network (Applied Innovation Technologies for Diagnosis and Conservation of Built Heritage), a regional research

Instantaneous frequency based newborn EEG seizure characterisation

NASA Astrophysics Data System (ADS)

Mesbah, Mostefa; O'Toole, John M.; Colditz, Paul B.; Boashash, Boualem

2012-12-01

The electroencephalogram (EEG), used to noninvasively monitor brain activity, remains the most reliable tool in the diagnosis of neonatal seizures. Due to their nonstationary and multi-component nature, newborn EEG seizures are better represented in the joint time-frequency domain than in either the time domain or the frequency domain. Characterising newborn EEG seizure nonstationarities helps to better understand their time-varying nature and, therefore, allow developing efficient signal processing methods for both modelling and seizure detection and classification. In this article, we used the instantaneous frequency (IF) extracted from a time-frequency distribution to characterise newborn EEG seizures. We fitted four frequency modulated (FM) models to the extracted IFs, namely a linear FM, a piecewise-linear FM, a sinusoidal FM, and a hyperbolic FM. Using a database of 30-s EEG seizure epochs acquired from 35 newborns, we were able to show that, depending on EEG channel, the sinusoidal and piecewise-linear FM models best fitted 80-98% of seizure epochs. To further characterise the EEG seizures, we calculated the mean frequency and frequency span of the extracted IFs. We showed that in the majority of the cases (>95%), the mean frequency resides in the 0.6-3 Hz band with a frequency span of 0.2-1 Hz. In terms of the frequency of occurrence of the four seizure models, the statistical analysis showed that there is no significant difference( p = 0.332) between the two hemispheres. The results also indicate that there is no significant differences between the two hemispheres in terms of the mean frequency ( p = 0.186) and the frequency span ( p = 0.302).

Do Toxicity Identification and Evaluation Laboratory-Based Methods Reflect Causes of Field Impairment?

EPA Science Inventory

Sediment Toxicity Identification and Evaluation (TIE) methods have been developed for both interstitial waters and whole sediments. These relatively simple laboratory methods are designed to identify specific toxicants or classes of toxicants in sediments; however, the question ...

Time-frequency characterisation of paediatric heart sounds

NASA Astrophysics Data System (ADS)

Leung, Terence Sze-Tat

1998-08-01

The operation of the heart can be monitored by the sounds it emits. Structural defects or malfunction of the heart valves will cause additional abnormal sounds such as murmurs and ejection clicks. This thesis aims to characterise the heart sounds of three groups of children who either have an Atrial Septal Defect (ASD), a Ventricular Septal Defect (VSD), or are normal. Two aspects of heart sounds have been specifically investigated; the time-frequency analysis of systolic murmurs and the identification of splitting patterns in the second heart sound. The analysis is based on 42 paediatric heart sound recordings. Murmurs are sounds generated by turbulent flow of blood in the heart. They can be found in patients with both pathological and non-pathological conditions. The acoustic quality of the murmurs generated in each heart condition are different. The first aspect of this work is to characterise the three types of murmurs in the time- frequency domain. Modern time-frequency methods including, the Wigner-Ville Distribution, Smoothed Pseudo Wigner-Ville Distribution, Choi-Williams Distribution and spectrogram have been applied to characterise the murmurs. It was found that the three classes of murmurs exhibited different signatures in their time-frequency representations. By performing Discriminant Analysis, it was shown that spectral features extracted from the time- frequency representations can be used to distinguish between the three classes. The second aspect of the research is to identify splitting patterns in the second heart sound, which consists of two acoustic components due to the closure of the aortic valve and pulmonary valve. The aortic valve usually closes before the pulmonary valve, introducing a time delay known as 'split'. The split normally varies in duration over the respiratory cycle. In certain pathologies such as the ASD, the split becomes fixed over the respiration cycle. A technique based on adaptive signal decomposition is developed to

SRC-I demonstration plant analytical laboratory methods manual. Final technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klusaritz, M.L.; Tewari, K.C.; Tiedge, W.F.

1983-03-01

This manual is a compilation of analytical procedures required for operation of a Solvent-Refined Coal (SRC-I) demonstration or commercial plant. Each method reproduced in full includes a detailed procedure, a list of equipment and reagents, safety precautions, and, where possible, a precision statement. Procedures for the laboratory's environmental and industrial hygiene modules are not included. Required American Society for Testing and Materials (ASTM) methods are cited, and ICRC's suggested modifications to these methods for handling coal-derived products are provided.

Characterisation of well-adhered ZrO2 layers produced on structured reactors using the sonochemical sol-gel method

NASA Astrophysics Data System (ADS)

Jodłowski, Przemysław J.; Chlebda, Damian K.; Jędrzejczyk, Roman J.; Dziedzicka, Anna; Kuterasiński, Łukasz; Sitarz, Maciej

2018-01-01

The aim of this study was to obtain thin zirconium dioxide coatings on structured reactors using the sonochemical sol-gel method. The preparation method of metal oxide layers on metallic structures was based on the synergistic combination of three approaches: the application of ultrasonic irradiation during the synthesis of Zr sol-gel based on a precursor solution containing zirconium(IV) n-propoxide, the addition of stabilszing agents, and the deposition of ZrO2 on the metallic structures using the dip-coating method. As a result, dense, uniform zirconium dioxide films were obtained on the FeCrAlloy supports. The structured reactors were characterised by various physicochemical methods, such as BET, AFM, EDX, XRF, XRD, XPS and in situ Raman spectroscopy. The results of the structural analysis by Raman and XPS spectroscopy confirmed that the metallic surface was covered by a ZrO2 layer without any impurities. SEM/EDX mapping revealed that the deposited ZrO2 covered the metallic support uniformly. The mechanical and high temperature tests showed that the developed ultrasound assisted sol-gel method is an efficient way to obtain thin, well-adhered zirconium dioxide layers on the structured reactors. The prepared metallic supports covered with thin ZrO2 layers may be a good alternative to layered structured reactors in several dynamics flow processes, for example for gas exhaust abatement.

An easy, rapid and inexpensive method to monitor tributyltin (TBT) toxicity in the laboratory.

PubMed

Cruz, Andreia; Moreira, Rafael; Mendo, Sónia

2014-05-01

Tributyltin (TBT) contamination remains a major problem worldwide. Many laboratories are committed to the development of remediation methodologies that could help reduce the negative impact of this compound in the environment. Furthermore, it is important to have at hand simple methodologies for evaluating TBT toxicity in the laboratory, besides the use of complex and costly analytical instrumentation. With that purpose, a method was adapted that is based on the inhibition of growth of an indicator strain, Micrococcus luteus ATCC 9341, under TBT. Different types of matrices, of TBT concentrations and sample treatments were tested. The results herein reported show that the bioassay method can be applied for both aqueous and soil samples and also for a high range of TBT concentrations (at least up to 500 μmol/L). Besides being cheap and easy to perform, it can be performed in any laboratory. Additionally, one possible application of the method to monitor TBT degradation is presented as an example.

Molecular characterisation of enteroinvasive Escherichia coli O136:K78 isolates from patients of a diarrhoea outbreak in China.

PubMed

Zhou, X; Xia, W; Tu, J; Xue, L; Ni, X

2015-01-01

A diarrhoea outbreak occurred in a kindergarten, which caused 21 relevant infected cases. Our object was to confirm the pathogens and their molecular characterisation. Faecal samples from 21 patients were collected on the 3rd day after their symptom onset, and a regular epidemiological investigation was conducted. Bacterial isolation was performed in accordance with standard laboratory protocol, serological and molecular characterisations were determined by serum agglutination test and real-time polymerase chain reaction (PCR) method, respectively. The pulsed field gel electrophoresis (PFGE) and 16S rRNAs were conducted to determine the homology. Eleven enteroinvasive Escherichia coli (EIEC) O136:K78 strains were isolated. The serum agglutination test showed that all strains' serotypes were E. coli (EIEC) O136:K78. Real-time PCR showed that 10 (91%) strains carried the invasion plasmid antigen H gene (ipaH), carried by all four Shigella species and EIEC. The strain that didn't carry the ipaH gene had different biochemical reactions of L-lizyna and L-rhamnose with the other strains. The complete 16S rRNA sequences showed 98.4% identity between ipaH-negative isolate and the others, and the PFGE indicated that the ipaH-negative isolate was not homological with other isolates in this diarrhoea outbreak. The diarrhoea outbreak was caused by E. coli (EIEC) O136:K78.

A Manual of Simplified Laboratory Methods for Operators of Wastewater Treatment Facilities.

ERIC Educational Resources Information Center

Westerhold, Arnold F., Ed.; Bennett, Ernest C., Ed.

This manual is designed to provide the small wastewater treatment plant operator, as well as the new or inexperienced operator, with simplified methods for laboratory analysis of water and wastewater. It is emphasized that this manual is not a replacement for standard methods but a guide for plants with insufficient equipment to perform analyses…

Multi-Laboratory Study of Five Methods for the Determination of Brevetoxins in Shellfish Tissue Extracts.

PubMed

Dickey, Robert W; Plakas, Steven M; Jester, Edward L E; El Said, Kathleen R; Johannessen, Jan N; Flewelling, Leanne J; Scott, Paula; Hammond, Dan G; Van Dolah, Frances M; Leighfield, Tod A; Bottein Dachraoui, Marie-Yasmine; Ramsdell, John S; Pierce, Richard H; Henry, Mike S; Poli, Mark A; Walker, Calvin; Kurtz, Jan; Naar, Jerome; Baden, Daniel G; Musser, Steve M; White, Kevin D; Truman, Penelope; Miller, Aaron; Hawryluk, Timothy P; Wekell, Marleen M; Stirling, David; Quilliam, Michael A; Lee, Jung K

A thirteen-laboratory comparative study tested the performance of four methods as alternatives to mouse bioassay for the determination of brevetoxins in shellfish. The methods were N2a neuroblastoma cell assay, two variations of the sodium channel receptor binding assay, competitive ELISA, and LC/MS. Three to five laboratories independently performed each method using centrally prepared spiked and naturally incurred test samples. Competitive ELISA and receptor binding (96-well format) compared most favorably with mouse bioassay. Between-laboratory relative standard deviations (RSDR) ranged from 10 to 20% for ELISA and 14 to 31% for receptor binding. Within-laboratory (RSDr) ranged from 6 to 15% for ELISA, and 5 to 31% for receptor binding. Cell assay was extremely sensitive but data variation rendered it unsuitable for statistical treatment. LC/MS performed as well as ELISA on spiked test samples but was inordinately affected by lack of toxin-metabolite standards, uniform instrumental parameters, or both, on incurred test samples. The ELISA and receptor binding assay are good alternatives to mouse bioassay for the determination of brevetoxins in shellfish.

On-ground and in-orbit characterisation plan for the PLATO CCD normal cameras

NASA Astrophysics Data System (ADS)

Gow, J. P. D.; Walton, D.; Smith, A.; Hailey, M.; Curry, P.; Kennedy, T.

2017-11-01

PLAnetary Transits and Ocillations (PLATO) is the third European Space Agency (ESA) medium class mission in ESA's cosmic vision programme due for launch in 2026. PLATO will carry out high precision un-interrupted photometric monitoring in the visible band of large samples of bright solar-type stars. The primary mission goal is to detect and characterise terrestrial exoplanets and their systems with emphasis on planets orbiting in the habitable zone, this will be achieved using light curves to detect planetary transits. PLATO uses a novel multi- instrument concept consisting of 26 small wide field cameras The 26 cameras are made up of a telescope optical unit, four Teledyne e2v CCD270s mounted on a focal plane array and connected to a set of Front End Electronics (FEE) which provide CCD control and readout. There are 2 fast cameras with high read-out cadence (2.5 s) for magnitude ~ 4-8 stars, being developed by the German Aerospace Centre and 24 normal (N) cameras with a cadence of 25 s to monitor stars with a magnitude greater than 8. The N-FEEs are being developed at University College London's Mullard Space Science Laboratory (MSSL) and will be characterised along with the associated CCDs. The CCDs and N-FEEs will undergo rigorous on-ground characterisation and the performance of the CCDs will continue to be monitored in-orbit. This paper discusses the initial development of the experimental arrangement, test procedures and current status of the N-FEE. The parameters explored will include gain, quantum efficiency, pixel response non-uniformity, dark current and Charge Transfer Inefficiency (CTI). The current in-orbit characterisation plan is also discussed which will enable the performance of the CCDs and their associated N-FEE to be monitored during the mission, this will include measurements of CTI giving an indication of the impact of radiation damage in the CCDs.

High resolution melting analysis: rapid and precise characterisation of recombinant influenza A genomes

PubMed Central

2013-01-01

Background High resolution melting analysis (HRM) is a rapid and cost-effective technique for the characterisation of PCR amplicons. Because the reverse genetics of segmented influenza A viruses allows the generation of numerous influenza A virus reassortants within a short time, methods for the rapid selection of the correct recombinants are very useful. Methods PCR primer pairs covering the single nucleotide polymorphism (SNP) positions of two different influenza A H5N1 strains were designed. Reassortants of the two different H5N1 isolates were used as a model to prove the suitability of HRM for the selection of the correct recombinants. Furthermore, two different cycler instruments were compared. Results Both cycler instruments generated comparable average melting peaks, which allowed the easy identification and selection of the correct cloned segments or reassorted viruses. Conclusions HRM is a highly suitable method for the rapid and precise characterisation of cloned influenza A genomes. PMID:24028349

The continued value of disk diffusion for assessing antimicrobial susceptibility in clinical laboratories: report from the Clinical and Laboratory Standards Institute Methods Development and Standardization Working Group.

PubMed

Humphries, Romney M; Kircher, Susan; Ferrell, Andrea; Krause, Kevin M; Malherbe, Rianna; Hsiung, Andre; Burnham, C A

2018-05-09

Expedited pathways to antimicrobial agent approval by the United States Food and Drug Administration (FDA) have led to increased delays between drug approval and the availability of FDA-cleared antimicrobial susceptibility testing (AST) devices. Antimicrobial disks for use with disk diffusion testing are among the first AST devices available to clinical laboratories. However, many laboratories are reluctant to implement a disk diffusion method for a variety of reasons, including dwindling proficiency with this method, interruptions to laboratory workflow, uncertainty surrounding the quality and reliability of a disk diffusion test, and perceived need to report an MIC to clinicians. This mini-review provides a report from the Clinical and Laboratory Standards Institute Working Group on Methods Development and Standardization on the current standards and clinical utility of disk diffusion testing. Copyright © 2018 American Society for Microbiology.

Comparability between various field and laboratory wood-stove emission-measurement methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCrillis, R.C.; Jaasma, D.R.

1991-01-01

The paper compares various field and laboratory woodstove emission measurement methods. In 1988, the U.S. EPA promulgated performance standards for residential wood heaters (woodstoves). Over the past several years, a number of field studies have been undertaken to determine the actual level of emission reduction achieved by new technology woodstoves in everyday use. The studies have required the development and use of particulate and gaseous emission sampling equipment compatible with operation in private homes. Since woodstoves are tested for certification in the laboratory using EPA Methods 5G and 5H, it is of interest to determine the correlation between these regulatorymore » methods and the inhouse equipment. Two inhouse sampling systems have been used most widely: one is an intermittent, pump-driven particulate sampler that collects particulate and condensible organics on a filter and organic adsorbent resin; and the other uses an evacuated cylinder as the motive force and particulate and condensible organics are collected in a condenser and dual filter. Both samplers can operate unattended for 1-week periods. A large number of tests have been run comparing Methods 5G and 5H to both samplers. The paper presents these comparison data and determines the relationships between regulations and field samplers.« less

Method for evaluation of laboratory craters using crater detection algorithm for digital topography data

NASA Astrophysics Data System (ADS)

Salamunićcar, Goran; Vinković, Dejan; Lončarić, Sven; Vučina, Damir; Pehnec, Igor; Vojković, Marin; Gomerčić, Mladen; Hercigonja, Tomislav

In our previous work the following has been done: (1) the crater detection algorithm (CDA) based on digital elevation model (DEM) has been developed and the GT-115225 catalog has been assembled [GRS, 48 (5), in press, doi:10.1109/TGRS.2009.2037750]; and (2) the results of comparison between explosion-induced laboratory craters in stone powder surfaces and GT-115225 have been presented using depth/diameter measurements [41stLPSC, Abstract #1428]. The next step achievable using the available technology is to create 3D scans of such labo-ratory craters, in order to compare different properties with simple Martian craters. In this work, we propose a formal method for evaluation of laboratory craters, in order to provide objective, measurable and reproducible estimation of the level of achieved similarity between these laboratory and real impact craters. In the first step, the section of MOLA data for Mars (or SELENE LALT for Moon) is replaced with one or several 3D-scans of laboratory craters. Once embedment was done, the CDA can be used to find out whether this laboratory crater is similar enough to real craters, as to be recognized as a crater by the CDA. The CDA evaluation using ROC' curve represents how true detection rate (TDR=TP/(TP+FN)=TP/GT) depends on the false detection rate (FDR=FP/(TP+FP)). Using this curve, it is now possible to define the measure of similarity between laboratory and real impact craters, as TDR or FDR value, or as a distance from the bottom-right origin of the ROC' curve. With such an approach, the reproducible (formally described) method for evaluation of laboratory craters is provided.

Laboratory Evaluation of Acoustic Backscatter and LISST Methods for Measurements of Suspended Sediments

PubMed Central

Meral, Ramazan

2008-01-01

The limitation of traditional sampling method to provide detailed spatial and temporal profiles of suspended sediment concentration has led to an interest in alternative devices and methods based on scattering of underwater sound and light. In the present work, acoustic backscatter and LISST (the Laser In Situ Scattering Transmissometry) devices, and methodologies were given. Besides a laboratory study was conducted to compare pumping methods for different sediment radiuses at the same concentration. The glass spheres (ballotini) of three different radiuses of 115, 137 and 163 μm were used to obtain suspension in the sediment tower at laboratory. A quite good agreement was obtained between these methods and pumping results with the range at 60.6-94.2% for sediment concentration and 91.3-100% for radius measurements. These results and the other studies show that these methods have potential for research tools for sediment studies. In addition further studies are needed to determine the ability of these methods for sediment measurement under different water and sediment material conditions. PMID:27879747

A method for developing outcome measures in the clinical laboratory.

PubMed

Jones, J

1996-01-01

Measuring and reporting outcomes in health care is becoming more important for quality assessment, utilization assessment, accreditation standards, and negotiating contracts in managed care. How does one develop an outcome measure for the laboratory to assess the value of the services? A method is described which outlines seven steps in developing outcome measures for a laboratory service or process. These steps include the following: 1. Identify the process or service to be monitored for performance and outcome assessment. 2. If necessary, form an multidisciplinary team of laboratory staff, other department staff, physicians, and pathologists. 3. State the purpose of the test or service including a review of published data for the clinical pathological correlation. 4. Prepare a process cause and effect diagram including steps critical to the outcome. 5. Identify key process variables that contribute to positive or negative outcomes. 6. Identify outcome measures that are not process measures. 7. Develop an operational definition, identify data sources, and collect data. Examples, including a process cause and effect diagram, process variables, and outcome measures, are given using the Therapeutic Drug Monitoring service (TDM). A summary of conclusions and precautions for outcome measurement is then provided.

Inter-laboratory validation of an inexpensive streamlined method to measure inorganic arsenic in rice grain.

PubMed

Chaney, Rufus L; Green, Carrie E; Lehotay, Steven J

2018-05-04

With the establishment by CODEX of a 200 ng/g limit of inorganic arsenic (iAs) in polished rice grain, more analyses of iAs will be necessary to ensure compliance in regulatory and trade applications, to assess quality control in commercial rice production, and to conduct research involving iAs in rice crops. Although analytical methods using high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) have been demonstrated for full speciation of As, this expensive and time-consuming approach is excessive when regulations are based only on iAs. We report a streamlined sample preparation and analysis of iAs in powdered rice based on heated extraction with 0.28 M HNO 3 followed by hydride generation (HG) under control of acidity and other simple conditions. Analysis of iAs is then conducted using flow-injection HG and inexpensive ICP-atomic emission spectroscopy (AES) or other detection means. A key innovation compared with previous methods was to increase the acidity of the reagent solution with 4 M HCl (prior to reduction of As 5+ to As 3+ ), which minimized interferences from dimethylarsinic acid. An inter-laboratory method validation was conducted among 12 laboratories worldwide in the analysis of six shared blind duplicates and a NIST Standard Reference Material involving different types of rice and iAs levels. Also, four laboratories used the standard HPLC-ICP-MS method to analyze the samples. The results between the methods were not significantly different, and the Horwitz ratio averaged 0.52 for the new method, which meets official method validation criteria. Thus, the simpler, more versatile, and less expensive method may be used by laboratories for several purposes to accurately determine iAs in rice grain. Graphical abstract Comparison of iAs results from new and FDA methods.

Novel laboratory methods for determining the fine scale electrical resistivity structure of core

NASA Astrophysics Data System (ADS)

Haslam, E. P.; Gunn, D. A.; Jackson, P. D.; Lovell, M. A.; Aydin, A.; Prance, R. J.; Watson, P.

2014-12-01

High-resolution electrical resistivity measurements are made on saturated rocks using novel laboratory instrumentation and multiple electrical voltage measurements involving in principle a four-point electrode measurement but with a single, moving electrode. Flat, rectangular core samples are scanned by varying the electrode position over a range of hundreds of millimetres with an accuracy of a tenth of a millimetre. Two approaches are tested involving a contact electrode and a non-contact electrode arrangement. The first galvanic method uses balanced cycle switching of a floating direct current (DC) source to minimise charge polarisation effects masking the resistivity distribution related to fine scale structure. These contacting electrode measurements are made with high common mode noise rejection via differential amplification with respect to a reference point within the current flow path. A computer based multifunction data acquisition system logs the current through the sample and voltages along equipotentials from which the resistivity measurements are derived. Multiple measurements are combined to create images of the surface resistivity structure, with variable spatial resolution controlled by the electrode spacing. Fine scale sedimentary features and open fractures in saturated rocks are interpreted from the measurements with reference to established relationships between electrical resistivity and porosity. Our results successfully characterise grainfall lamination and sandflow cross-stratification in a brine saturated, dune bedded core sample representative of a southern North Sea reservoir sandstone, studied using the system in constant current, variable voltage mode. In contrast, in a low porosity marble, identification of open fracture porosity against a background very low matrix porosity is achieved using the constant voltage, variable current mode. This new system is limited by the diameter of the electrode that for practical reasons can only be

Characterisation of Pomegranate-Husk Polyphenols and Semi-Preparative Fractionation of Punicalagin.

PubMed

Aguilar-Zárate, Pedro; Wong-Paz, Jorge E; Michel, Mariela; Buenrostro-Figueroa, Juan; Díaz, Hugo R; Ascacio, Juan A; Contreras-Esquivel, Juan C; Gutiérrez-Sánchez, Gerardo; Aguilar, Cristóbal N

2017-09-01

Pomegranate-husk is the main by-product generated from the pomegranate industry. It is a potential source of compounds highly appreciated by different costumers. Punicalagin is the main compound present in pomegranate-husk. To characterise the pomegranate-husk total polyphenols by HPLC-ESI-MS and to establish a method for the recovery of punicalagin using a medium pressure liquid chromatography (MPLC) system. The characterisation of total pomegranate-husk polyphenols was carried out using liquid chromatography coupled to mass spectrometry. Thus, 200 mg of pomegranate-husk polyphenols were fractionated by MPLC. The isolated punicalagin was characterised by HPLC-MS and was tested as standard reagent for the measurement of its scavenging capacity reducing DPPH and ABTS radicals. Twenty peaks were identified by analytical HPLC-MS analysis from the pomegranate-husk polyphenols. The main compounds were the punicalagin anomers, punicalin and ellagic acid. The MPLC method allowed three fractions to be obtained. In fraction three 39.40 ± 8.06 mg of punicalagin anomers (purity > 97.9%) were recovered. The scavenging capacity of punicalagin showed an IC 50 of 109.53 and 151.50 μg/mL for DPPH and ABTS radicals, respectively. The MPLC system was an excellent tool for the separation of the main ellagitannins from pomegranate husk and for the isolation of punicalagin anomers. Fraction three was rich in high purity punicalagin anomers. The IC 50 was obtained for DPPH and ABTS radicals. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Quantitative characterisation of audio data by ordinal symbolic dynamics

NASA Astrophysics Data System (ADS)

Aschenbrenner, T.; Monetti, R.; Amigó, J. M.; Bunk, W.

2013-06-01

Ordinal symbolic dynamics has developed into a valuable method to describe complex systems. Recently, using the concept of transcripts, the coupling behaviour of systems was assessed, combining the properties of the symmetric group with information theoretic ideas. In this contribution, methods from the field of ordinal symbolic dynamics are applied to the characterisation of audio data. Coupling complexity between frequency bands of solo violin music, as a fingerprint of the instrument, is used for classification purposes within a support vector machine scheme. Our results suggest that coupling complexity is able to capture essential characteristics, sufficient to distinguish among different violins.

Safety in the Chemical Laboratory--Chemical Management: A Method for Waste Reduction.

ERIC Educational Resources Information Center

Pine, Stanley H.

1984-01-01

Discusses methods for reducing or eliminating waste disposal problems in the chemistry laboratory, considering both economic and environmental aspects of the problems. Proposes inventory control, shared use, solvent recycling, zero effluent, and various means of disposing of chemicals. (JM)

The Writing Laboratory: Organization, Management, and Methods.

ERIC Educational Resources Information Center

Steward, Joyce S.; Croft, Mary K.

The four chapters of this book move from the history, philosophy, and approaches that writing laboratories encompass to a look at the many facets of their organization before treating in detail the actual teaching process and the practical elements of writing laboratory management. Chapter one notes the growth of writing labs and discusses…

Feature-based characterisation of signature topography in laser powder bed fusion of metals

NASA Astrophysics Data System (ADS)

Senin, Nicola; Thompson, Adam; Leach, Richard

2018-04-01

The use of state-of-the-art areal topography measurement instrumentation allows for a high level of detail in the acquisition of topographic information at micrometric scales. The 3D geometric models of surface topography obtained from measured data create new opportunities for the investigation of manufacturing processes through characterisation of the surfaces of manufactured parts. Conventional methods for quantitative assessment of topography usually only involve the computation of texture parameters, summary indicators of topography-related characteristics that are computed over the investigated area. However, further useful information may be obtained through characterisation of signature topographic formations, as more direct indicators of manufacturing process behaviour and performance. In this work, laser powder bed fusion of metals is considered. An original algorithmic method is proposed to isolate relevant topographic formations and to quantify their dimensional and geometric properties, using areal topography data acquired by state-of-the-art areal topography measurement instrumentation.

Characterisation of the hydrology of an estuarine wetland

NASA Astrophysics Data System (ADS)

Hughes, Catherine E.; Binning, Philip; Willgoose, Garry R.

1998-11-01

The intertidal zone of estuarine wetlands is characterised by a transition from a saline marine environment to a freshwater environment with increasing distance from tidal streams. An experimental site has been established in an area of mangrove and salt marsh wetland in the Hunter River estuary, Australia, to characterise and provide data for a model of intertidal zone hydrology. The experimental site is designed to monitor water fluxes at a small scale (36 m). A weather station and groundwater monitoring wells have been installed and hydraulic head and tidal levels are monitored over a 10-week period along a short one-dimensional transect covering the transition between the tidal and freshwater systems. Soil properties have been determined in the laboratory and the field. A two-dimensional finite element model of the site was developed using SEEP/W to analyse saturated and unsaturated pore water movement. Modification of the water retention function to model crab hole macropores was found necessary to reproduce the observed aquifer response. Groundwater response to tidal fluctuations was observed to be almost uniform beyond the intertidal zone, due to the presence of highly permeable subsurface sediments below the less permeable surface sediments. Over the 36 m transect, tidal forcing was found to generate incoming fluxes in the order of 0.22 m 3/day per metre width of creek bank during dry periods, partially balanced by evaporative fluxes of about 0.13 m 3/day per metre width. During heavy rainfall periods, rainfall fluxes were about 0.61 m 3/day per metre width, dominating the water balance. Evapotranspiration rates were greater for the salt marsh dominated intertidal zone than the non-tidal zone. Hypersalinity and salt encrustation observed show that evapotranspiration fluxes are very important during non-rainfall periods and are believed to significantly influence salt concentration both in the surface soil matrix and the underlying aquifer.

Mathematical modelling and quantitative methods.

PubMed

Edler, L; Poirier, K; Dourson, M; Kleiner, J; Mileson, B; Nordmann, H; Renwick, A; Slob, W; Walton, K; Würtzen, G

2002-01-01

The present review reports on the mathematical methods and statistical techniques presently available for hazard characterisation. The state of the art of mathematical modelling and quantitative methods used currently for regulatory decision-making in Europe and additional potential methods for risk assessment of chemicals in food and diet are described. Existing practices of JECFA, FDA, EPA, etc., are examined for their similarities and differences. A framework is established for the development of new and improved quantitative methodologies. Areas for refinement, improvement and increase of efficiency of each method are identified in a gap analysis. Based on this critical evaluation, needs for future research are defined. It is concluded from our work that mathematical modelling of the dose-response relationship would improve the risk assessment process. An adequate characterisation of the dose-response relationship by mathematical modelling clearly requires the use of a sufficient number of dose groups to achieve a range of different response levels. This need not necessarily lead to an increase in the total number of animals in the study if an appropriate design is used. Chemical-specific data relating to the mode or mechanism of action and/or the toxicokinetics of the chemical should be used for dose-response characterisation whenever possible. It is concluded that a single method of hazard characterisation would not be suitable for all kinds of risk assessments, and that a range of different approaches is necessary so that the method used is the most appropriate for the data available and for the risk characterisation issue. Future refinements to dose-response characterisation should incorporate more clearly the extent of uncertainty and variability in the resulting output.

Percent body fat estimations in college men using field and laboratory methods: a three-compartment model approach.

PubMed

Moon, Jordan R; Tobkin, Sarah E; Smith, Abbie E; Roberts, Michael D; Ryan, Eric D; Dalbo, Vincent J; Lockwood, Chris M; Walter, Ashley A; Cramer, Joel T; Beck, Travis W; Stout, Jeffrey R

2008-04-21

Methods used to estimate percent body fat can be classified as a laboratory or field technique. However, the validity of these methods compared to multiple-compartment models has not been fully established. The purpose of this study was to determine the validity of field and laboratory methods for estimating percent fat (%fat) in healthy college-age men compared to the Siri three-compartment model (3C). Thirty-one Caucasian men (22.5 +/- 2.7 yrs; 175.6 +/- 6.3 cm; 76.4 +/- 10.3 kg) had their %fat estimated by bioelectrical impedance analysis (BIA) using the BodyGram computer program (BIA-AK) and population-specific equation (BIA-Lohman), near-infrared interactance (NIR) (Futrex(R) 6100/XL), four circumference-based military equations [Marine Corps (MC), Navy and Air Force (NAF), Army (A), and Friedl], air-displacement plethysmography (BP), and hydrostatic weighing (HW). All circumference-based military equations (MC = 4.7% fat, NAF = 5.2% fat, A = 4.7% fat, Friedl = 4.7% fat) along with NIR (NIR = 5.1% fat) produced an unacceptable total error (TE). Both laboratory methods produced acceptable TE values (HW = 2.5% fat; BP = 2.7% fat). The BIA-AK, and BIA-Lohman field methods produced acceptable TE values (2.1% fat). A significant difference was observed for the MC and NAF equations compared to both the 3C model and HW (p < 0.006). Results indicate that the BP and HW are valid laboratory methods when compared to the 3C model to estimate %fat in college-age Caucasian men. When the use of a laboratory method is not feasible, BIA-AK, and BIA-Lohman are acceptable field methods to estimate %fat in this population.

Adaptation of LASCA method for diagnostics of malignant tumours in laboratory animals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ul'yanov, S S; Laskavyi, V N; Glova, Alina B

The LASCA method is adapted for diagnostics of malignant neoplasms in laboratory animals. Tumours are studied in mice of Balb/c inbred line after inoculation of cells of syngeneic myeloma cell line Sp.2/0 Ag.8. The appropriateness of using the tLASCA method in tumour investigations is substantiated; its advantages in comparison with the sLASCA method are demonstrated. It is found that the most informative characteristic, indicating the presence of a tumour, is the fractal dimension of LASCA images.

Laboratory test methods for evaluating the fire response of aerospace materials

NASA Technical Reports Server (NTRS)

Hilado, C. J.

1979-01-01

The test methods which were developed or evaluated were intended to serve as means of comparing materials on the basis of specific responses under specific sets of test conditions, using apparatus, facilities, and personnel that would be within the capabilities of perhaps the majority of laboratories. Priority was given to test methods which showed promise of addressing the pre-ignition state of a potential fire. These test methods were intended to indicate which materials may present more hazard than others under specific test conditions. These test methods are discussed and arranged according to the stage of a fire to which they are most relevant. Some observations of material performance which resulted from this work are also discussed.

Percent body fat estimations in college men using field and laboratory methods: A three-compartment model approach

PubMed Central

Moon, Jordan R; Tobkin, Sarah E; Smith, Abbie E; Roberts, Michael D; Ryan, Eric D; Dalbo, Vincent J; Lockwood, Chris M; Walter, Ashley A; Cramer, Joel T; Beck, Travis W; Stout, Jeffrey R

2008-01-01

Background Methods used to estimate percent body fat can be classified as a laboratory or field technique. However, the validity of these methods compared to multiple-compartment models has not been fully established. The purpose of this study was to determine the validity of field and laboratory methods for estimating percent fat (%fat) in healthy college-age men compared to the Siri three-compartment model (3C). Methods Thirty-one Caucasian men (22.5 ± 2.7 yrs; 175.6 ± 6.3 cm; 76.4 ± 10.3 kg) had their %fat estimated by bioelectrical impedance analysis (BIA) using the BodyGram™ computer program (BIA-AK) and population-specific equation (BIA-Lohman), near-infrared interactance (NIR) (Futrex® 6100/XL), four circumference-based military equations [Marine Corps (MC), Navy and Air Force (NAF), Army (A), and Friedl], air-displacement plethysmography (BP), and hydrostatic weighing (HW). Results All circumference-based military equations (MC = 4.7% fat, NAF = 5.2% fat, A = 4.7% fat, Friedl = 4.7% fat) along with NIR (NIR = 5.1% fat) produced an unacceptable total error (TE). Both laboratory methods produced acceptable TE values (HW = 2.5% fat; BP = 2.7% fat). The BIA-AK, and BIA-Lohman field methods produced acceptable TE values (2.1% fat). A significant difference was observed for the MC and NAF equations compared to both the 3C model and HW (p < 0.006). Conclusion Results indicate that the BP and HW are valid laboratory methods when compared to the 3C model to estimate %fat in college-age Caucasian men. When the use of a laboratory method is not feasible, BIA-AK, and BIA-Lohman are acceptable field methods to estimate %fat in this population. PMID:18426582

The Effects of Using Jigsaw Method Based on Cooperative Learning Model in the Undergraduate Science Laboratory Practices

ERIC Educational Resources Information Center

Karacop, Ataman

2017-01-01

The main aim of the present study is to determine the influence of a Jigsaw method based on cooperative learning and a confirmatory laboratory method on prospective science teachers' achievements of physics in science teaching laboratory practice courses. The sample of this study consisted of 33 female and 15 male third-grade prospective science…

The communication of laboratory investigations by university entrants

NASA Astrophysics Data System (ADS)

Campbell, Bob; Kaunda, Loveness; Allie, Saalih; Buffler, Andy; Lubben, Fred

2000-10-01

The purpose of the study reported here was to analyse the ways in which unversity entrant science students carry out and communicate experimental activities and to identify a model to explain characteristic communication practices. The study was prompted by a need to inform the development of an introductory laboratory course. The students studied shared an educational background characterised by a lack of experience with laboratory work and scientific writing. Seven groups of three students were studied. The investigative strategies of these groups were observed. Laboratory reports were used to identify the ways in which students communicated these strategies. Data are presented that show a discrepancy between the strategies used and those reported. The results suggest that: (i) students' perceptions of the purpose of a laboratory task influence their decisions on what to report; (ii) understandings of laboratory procedures greatly influence their decision on what to report and on how much detail to include in a report and; (iii) knowledge of discourse rules contributes to effective reporting. It is concluded that students' communication of an investigation results from the differential operation of various perceptual filters that determine both the procedural and discourse elements of their reports. It is recommended that the communication of science should be taught explicitly and alongside the procedures and concepts of science.

A chemometric approach to the characterisation of historical mortars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rampazzi, L.; Pozzi, A.; Sansonetti, A.

2006-06-15

The compositional knowledge of historical mortars is of great concern in case of provenance and dating investigations and of conservation works since the nature of the raw materials suggests the most compatible conservation products. The classic characterisation usually goes through various analytical determinations, while conservation laboratories call for simple and quick analyses able to enlighten the nature of mortars, usually in terms of the binder fraction. A chemometric approach to the matter is here undertaken. Specimens of mortars were prepared with calcitic and dolomitic binders and analysed by Atomic Spectroscopy. Principal Components Analysis (PCA) was used to investigate the featuresmore » of specimens and samples. A Partial Least Square (PLS1) regression was done in order to predict the binder/aggregate ratio. The model was applied to historical mortars from the churches of St. Lorenzo (Milan) and St. Abbondio (Como). The accordance between the predictive model and the real samples is discussed.« less

Children's colour choices for completing drawings of affectively characterised topics.

PubMed

Burkitt, Esther; Barrett, Martyn; Davis, Alyson

2003-03-01

This study was designed to explore whether or not children systematically use particular colours when completing drawings of affectively characterised topics. Three hundred and thirty 4-11-year-old children were subdivided into three conditions, colouring in a drawing of a man, a dog, or a tree, respectively. The children completed two test sessions in counterbalanced order. In one session, children rated and ranked ten colours in order of preference. In the other session, children completed three colouring tasks in which they had to colour in three identical figures but which had been given different affective characterisations: a neutrally characterised figure, a figure characterised as nasty, and a figure characterised as nice. It was found that, in all age groups and for all topics, the children used their more preferred colours for the nice figures, their least preferred colours for the nasty figures, and colours rated intermediately for the neutral figures. It was also found that, in all age groups and for all topics, black tended to be the most frequently chosen colour for colouring in the drawings of the negatively characterised figures. By contrast, primary colours were predominantly selected for the neutral figure, while a wide range of mainly primary and secondary colours were chosen for colouring in the nice figure. These results suggest that children are able to alter systematically their use of colour during picture completion tasks in response to differential affective topic characterisations, and that even very young children are able to use colours symbolically.

49 CFR 40.185 - Through what methods and to whom must a laboratory report split specimen results?

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false Through what methods and to whom must a laboratory... § 40.185 Through what methods and to whom must a laboratory report split specimen results? (a) As the... copy of the fully-completed Copy 1 of the CCF, which has been signed by the certifying scientist. (c...

Characterisation of serpin polymers in vitro and in vivo.

PubMed

Belorgey, Didier; Irving, James A; Ekeowa, Ugo I; Freeke, Joanna; Roussel, Benoit D; Miranda, Elena; Pérez, Juan; Robinson, Carol V; Marciniak, Stefan J; Crowther, Damian C; Michel, Claire H; Lomas, David A

2011-03-01

Neuroserpin is a member of the serine protease inhibitor or serpin superfamily of proteins. It is secreted by neurones and plays an important role in the regulation of tissue plasminogen activator at the synapse. Point mutations in the neuroserpin gene cause the autosomal dominant dementia familial encephalopathy with neuroserpin inclusion bodies or FENIB. This is one of a group of disorders caused by mutations in the serpins that are collectively known as the serpinopathies. Others include α(1)-antitrypsin deficiency and deficiency of C1 inhibitor, antithrombin and α(1)-antichymotrypsin. The serpinopathies are characterised by delays in protein folding and the retention of ordered polymers of the mutant serpin within the cell of synthesis. The clinical phenotype results from either a toxic gain of function from the inclusions or a loss of function, as there is insufficient protease inhibitor to regulate important proteolytic cascades. We describe here the methods required to characterise the polymerisation of neuroserpin and draw parallels with the polymerisation of α(1)-antitrypsin. It is important to recognise that the conditions in which experiments are performed will have a major effect on the findings. For example, incubation of monomeric serpins with guanidine or urea will produce polymers that are not found in vivo. The characterisation of the pathological polymers requires heating of the folded protein or alternatively the assessment of ordered polymers from cell and animal models of disease or from the tissues of humans who carry the mutation. Copyright © 2010 Elsevier Inc. All rights reserved.

FragIdent--automatic identification and characterisation of cDNA-fragments.

PubMed

Seelow, Dominik; Goehler, Heike; Hoffmann, Katrin

2009-03-02

Many genetic studies and functional assays are based on cDNA fragments. After the generation of cDNA fragments from an mRNA sample, their content is at first unknown and must be assigned by sequencing reactions or hybridisation experiments. Even in characterised libraries, a considerable number of clones are wrongly annotated. Furthermore, mix-ups can happen in the laboratory. It is therefore essential to the relevance of experimental results to confirm or determine the identity of the employed cDNA fragments. However, the manual approach for the characterisation of these fragments using BLAST web interfaces is not suited for larger number of sequences and so far, no user-friendly software is publicly available. Here we present the development of FragIdent, an application for the automatic identification of open reading frames (ORFs) within cDNA-fragments. The software performs BLAST analyses to identify the genes represented by the sequences and suggests primers to complete the sequencing of the whole insert. Gene-specific information as well as the protein domains encoded by the cDNA fragment are retrieved from Internet-based databases and included in the output. The application features an intuitive graphical interface and is designed for researchers without any bioinformatics skills. It is suited for projects comprising up to several hundred different clones. We used FragIdent to identify 84 cDNA clones from a yeast two-hybrid experiment. Furthermore, we identified 131 protein domains within our analysed clones. The source code is freely available from our homepage at http://compbio.charite.de/genetik/FragIdent/.

De novo design, synthesis and characterisation of MP3, a new catalytic four-helix bundle hemeprotein.

PubMed

Faiella, Marina; Maglio, Ornella; Nastri, Flavia; Lombardi, Angela; Lista, Liliana; Hagen, Wilfred R; Pavone, Vincenzo

2012-12-07

A new artificial metalloenzyme, MP3 (MiniPeroxidase 3), designed by combining the excellent structural properties of four-helix bundle protein scaffolds with the activity of natural peroxidases, was synthesised and characterised. This new hemeprotein model was developed by covalently linking the deuteroporphyrin to two peptide chains of different compositions to obtain an asymmetric helix-loop-helix/heme/helix-loop-helix sandwich arrangement, characterised by 1) a His residue on one chain that acts as an axial ligand to the iron ion; 2) a vacant distal site that is able to accommodate exogenous ligands or substrates; and 3) an Arg residue in the distal site that should assist in hydrogen peroxide activation to give an HRP-like catalytic process. MP3 was synthesised and characterised as its iron complex. CD measurements revealed the high helix-forming propensity of the peptide, confirming the appropriateness of the model procedure; UV/Vis, MCD and EPR experiments gave insights into the coordination geometry and the spin state of the metal. Kinetic experiments showed that Fe(III)-MP3 possesses peroxidase-like activity comparable to R38A-hHRP, highlighting the possibility of mimicking the functional features of natural enzymes. The synergistic application of de novo design methods, synthetic procedures, and spectroscopic characterisation, described herein, demonstrates a method by which to implement and optimise catalytic activity for an enzyme mimetic. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Percent body fat estimations in college women using field and laboratory methods: a three-compartment model approach

PubMed Central

Moon, Jordan R; Hull, Holly R; Tobkin, Sarah E; Teramoto, Masaru; Karabulut, Murat; Roberts, Michael D; Ryan, Eric D; Kim, So Jung; Dalbo, Vincent J; Walter, Ashley A; Smith, Abbie T; Cramer, Joel T; Stout, Jeffrey R

2007-01-01

Background Methods used to estimate percent body fat can be classified as a laboratory or field technique. However, the validity of these methods compared to multiple-compartment models has not been fully established. This investigation sought to determine the validity of field and laboratory methods for estimating percent fat (%fat) in healthy college-age women compared to the Siri three-compartment model (3C). Methods Thirty Caucasian women (21.1 ± 1.5 yrs; 164.8 ± 4.7 cm; 61.2 ± 6.8 kg) had their %fat estimated by BIA using the BodyGram™ computer program (BIA-AK) and population-specific equation (BIA-Lohman), NIR (Futrex® 6100/XL), a quadratic (SF3JPW) and linear (SF3WB) skinfold equation, air-displacement plethysmography (BP), and hydrostatic weighing (HW). Results All methods produced acceptable total error (TE) values compared to the 3C model. Both laboratory methods produced similar TE values (HW, TE = 2.4%fat; BP, TE = 2.3%fat) when compared to the 3C model, though a significant constant error (CE) was detected for HW (1.5%fat, p ≤ 0.006). The field methods produced acceptable TE values ranging from 1.8 – 3.8 %fat. BIA-AK (TE = 1.8%fat) yielded the lowest TE among the field methods, while BIA-Lohman (TE = 2.1%fat) and NIR (TE = 2.7%fat) produced lower TE values than both skinfold equations (TE > 2.7%fat) compared to the 3C model. Additionally, the SF3JPW %fat estimation equation resulted in a significant CE (2.6%fat, p ≤ 0.007). Conclusion Data suggest that the BP and HW are valid laboratory methods when compared to the 3C model to estimate %fat in college-age Caucasian women. When the use of a laboratory method is not feasible, NIR, BIA-AK, BIA-Lohman, SF3JPW, and SF3WB are acceptable field methods to estimate %fat in this population. PMID:17988393

Flotation of Mineral and Dyes: A Laboratory Experiment for Separation Method Molecular Hitchhikers

ERIC Educational Resources Information Center

Rappon, Tim; Sylvestre, Jarrett A.; Rappon, Manit

2016-01-01

Flotation as a method of separation is widely researched and is applied in many industries. It has been used to address a wide range of environmental issues including treatment of wastewater, recovery of heavy metals for recycling, extraction of minerals in mining, and so forth. This laboratory attempts to show how such a simple method can be used…

The high-throughput synthesis and phase characterisation of amphiphiles: a sweet case study.

PubMed

Feast, George C; Hutt, Oliver E; Mulet, Xavier; Conn, Charlotte E; Drummond, Calum J; Savage, G Paul

2014-03-03

A new method for the discovery of amphiphiles by using high-throughput (HT) methods to synthesise and characterise a library of galactose- and glucose-containing amphiphilic compounds is presented. The copper-catalysed azide–alkyne cycloaddition (CuAAC) “click” reaction between azide-tethered simple sugars and alkyne-substituted hydrophobic tails was employed to synthesise a library of compounds with systematic variations in chain length and unsaturation in a 24-vial array format. The liquid–crystalline phase behaviour was characterised in a HT manner by using synchrotron small-angle X-ray scattering (SSAXS). The observed structural variation with respect to chain parameters, including chain length and degree of unsaturation, is discussed, as well as hydration effects and degree of hydrogen bonding between head groups. The validity of our HT screening approach was verified by resynthesising a short-chain glucose amphiphile. A separate phase analysis of this compound confirmed the presence of numerous lyotropic liquid–crystalline phases.

The Application of Modern Powder Characterisation Methods in Product and Process Development of Solid Dosage Forms.

PubMed

Freeman, Tim; Brockbank, Katrina; Armstrong, Brian

2015-01-01

The pharmaceutical industry still produces the vast majority of their products, from powdered ingredients, in the form of solid doses. Despite their ubiquity, powders are difficult materials to characterise and understand, as evidenced by the frequent problems encountered during manufacture. The reason for this is their complex rheological behaviour coupled with numerous environmental variations, such as humidity. Equally, the range of processes used to manipulate powders subject them to extremes of stress from high compaction loads seen in compactors to the dispersed state seen in fluidised bed dryers. Thus, it is evident that ensuring that the powders characteristics are compatible with the way they are to be processed is a clear prerequisite for today's Quality by Design driven manufacturing. Modern, computer controlled instrumental techniques, including the dynamic, bulk and shear property measurements have enabled direct measurements of a powders response to aeration, consolidation and flow rate - all at low stresses - as well as quantifying shear and bulk properties (such as density, compressibility and permeability). In order to demonstrate how fully characterising a powder can be used in the design, operation and troubleshooting of processes, this paper will present examples of common pharmaceutical unit operations and the different powder characteristics that most influence the performance of each.

A new method for eliciting three speaking styles in the laboratory

PubMed Central

Harnsberger, James D.; Wright, Richard; Pisoni, David B.

2009-01-01

In this study, a method was developed to elicit three different speaking styles, reduced, citation, and hyperarticulated, using controlled sentence materials in a laboratory setting. In the first set of experiments, the reduced style was elicited by having twelve talkers read a sentence while carrying out a distractor task that involved recalling from short-term memory an individually-calibrated number of digits. The citation style corresponded to read speech in the laboratory. The hyperarticulated style was elicited by prompting talkers (twice) to reread the sentences more carefully. The results of perceptual tests with naïve listeners and an acoustic analysis showed that six of the twelve talkers produced a reduced style of speech for the test sentences in the distractor task relative to the same sentences in the citation style condition. In addition, all talkers consistently produced sentences in the citation and hyperarticulated styles. In the second set of experiments, the reduced style was elicited by increasing the number of digits in the distractor task by one (a heavier cognitive load). The procedures for eliciting citation and hyperarticulated sentences remained unchanged. Ten talkers were recorded in the second experiment. The results showed that six out of ten talkers differentiated all three styles as predicted (70% of all sentences recorded). In addition, all talkers consistently produced sentences in the citation and hyperarticulated styles. Overall, the results demonstrate that it is possible to elicit controlled sentence stimulus materials varying in speaking style in a laboratory setting, although the method requires further refinement to elicit these styles more consistently from individual participants. PMID:19562041

A new method for eliciting three speaking styles in the laboratory.

PubMed

Harnsberger, James D; Wright, Richard; Pisoni, David B

2008-04-01

In this study, a method was developed to elicit three different speaking styles, reduced, citation, and hyperarticulated, using controlled sentence materials in a laboratory setting. In the first set of experiments, the reduced style was elicited by having twelve talkers read a sentence while carrying out a distractor task that involved recalling from short-term memory an individually-calibrated number of digits. The citation style corresponded to read speech in the laboratory. The hyperarticulated style was elicited by prompting talkers (twice) to reread the sentences more carefully. The results of perceptual tests with naïve listeners and an acoustic analysis showed that six of the twelve talkers produced a reduced style of speech for the test sentences in the distractor task relative to the same sentences in the citation style condition. In addition, all talkers consistently produced sentences in the citation and hyperarticulated styles. In the second set of experiments, the reduced style was elicited by increasing the number of digits in the distractor task by one (a heavier cognitive load). The procedures for eliciting citation and hyperarticulated sentences remained unchanged. Ten talkers were recorded in the second experiment. The results showed that six out of ten talkers differentiated all three styles as predicted (70% of all sentences recorded). In addition, all talkers consistently produced sentences in the citation and hyperarticulated styles. Overall, the results demonstrate that it is possible to elicit controlled sentence stimulus materials varying in speaking style in a laboratory setting, although the method requires further refinement to elicit these styles more consistently from individual participants.

Free-living and laboratory gait characteristics in patients with multiple sclerosis

PubMed Central

Nair, K. P. S.; Clarke, Alison J.; Van der Meulen, Jill M.; Mazzà, Claudia

2018-01-01

Background Wearable sensors offer the potential to bring new knowledge to inform interventions in patients affected by multiple sclerosis (MS) by thoroughly quantifying gait characteristics and gait deficits from prolonged daily living measurements. The aim of this study was to characterise gait in both laboratory and daily life conditions for a group of patients with moderate to severe ambulatory impairment due to MS. To this purpose, algorithms to detect and characterise gait from wearable inertial sensors data were also validated. Methods Fourteen patients with MS were divided into two groups according to their disability level (EDSS 6.5–6.0 and EDSS 5.5–5.0, respectively). They performed both intermittent and continuous walking bouts (WBs) in a gait laboratory wearing waist and shank mounted inertial sensors. An algorithm (W-CWT) to estimate gait events and temporal parameters (mean and variability values) using data recorded from the waist mounted sensor (Dynaport, Mc Roberts) was tested against a reference algorithm (S-REF) based on the shank-worn sensors (OPAL, APDM). Subsequently, the accuracy of another algorithm (W-PAM) to detect and classify WBs was also tested. The validated algorithms were then used to quantify gait characteristics during short (sWB, 5–50 steps), intermediate (iWB, 51–100 steps) and long (lWB, >100 steps) daily living WBs and laboratory walking. Group means were compared using a two-way ANOVA. Results W-CWT compared to S-REF showed good gait event accuracy (0.05–0.10 s absolute error) and was not influenced by disability level. It slightly overestimated stride time in intermittent walking (0.012 s) and overestimated highly variability of temporal parameters in both intermittent (17.5%–58.2%) and continuous walking (11.2%–76.7%). The accuracy of W-PAM was speed-dependent and decreased with increasing disability. The ANOVA analysis showed that patients walked at a slower pace in daily living than in the laboratory. In daily

Using a Laboratory Simulator in the Teaching and Study of Chemical Processes in Estuarine Systems

ERIC Educational Resources Information Center

Garcia-Luque, E.; Ortega, T.; Forja, J. M.; Gomez-Parra, A.

2004-01-01

The teaching of Chemical Oceanography in the Faculty of Marine and Environmental Sciences of the University of Cadiz (Spain) has been improved since 1994 by the employment of a device for the laboratory simulation of estuarine mixing processes and the characterisation of the chemical behaviour of many substances that pass through an estuary. The…

An Enzymatic Clinical Chemistry Laboratory Experiment Incorporating an Introduction to Mathematical Method Comparison Techniques

ERIC Educational Resources Information Center

Duxbury, Mark

2004-01-01

An enzymatic laboratory experiment based on the analysis of serum is described that is suitable for students of clinical chemistry. The experiment incorporates an introduction to mathematical method-comparison techniques in which three different clinical glucose analysis methods are compared using linear regression and Bland-Altman difference…

Development of a perfusion reversed-phase high performance liquid chromatography method for the characterisation of maize products using multivariate analysis.

PubMed

Rodriguez-Nogales, J M; Garcia, M C; Marina, M L

2006-02-03

A perfusion reversed-phase high performance liquid chromatography (RP-HPLC) method has been designed to allow rapid (3.4 min) separations of maize proteins with high resolution. Several factors, such as extraction conditions, temperature, detection wavelength and type and concentration of ion-pairing agent were optimised. A fine optimisation of the gradient elution was also performed by applying experimental design. Commercial maize products for human consumption (flours, precocked flours, fried snacks and extruded snacks) were characterised for the first time by perfusion RP-HPLC and their chromatographic profiles allowed a differentiation among products relating the different technological process used for their preparation. Furthermore, applying discriminant analysis makes it possible to group the samples according with the technological process suffered by maize products, obtaining a good prediction in 92% of the samples.

Doing laboratory ethnography: reflections on method in scientific workplaces.

PubMed

Stephens, Neil; Lewis, Jamie

2017-04-01

Laboratory ethnography extended the social scientist's gaze into the day-to-day accomplishment of scientific practice. Here we reflect upon our own ethnographies of biomedical scientific workspaces to provoke methodological discussion on the doing of laboratory ethnography. What we provide is less a 'how to' guide and more a commentary on what to look for and what to look at. We draw upon our empirical research with stem cell laboratories and animal houses, teams producing robotic surgical tools, musicians sonifying data science, a psychiatric genetics laboratory, and scientists developing laboratory grown meat. We use these cases to example a set of potential ethnographic themes worthy of pursuit: science epistemics and the extended laboratory, the interaction order of scientific work, sensory realms and the rending of science as sensible, conferences as performative sites, and the spaces, places and temporalities of scientific work.

The Significance of A Neglected Romanian Book - "The Methods of the Clinical Laboratory", by Ioan Manta and Alexandru Ciplea.

PubMed

Barsu, Cristian

2017-04-06

"The Methods of Clinical Laboratory" was the first comprehensive Romanian book in the medical laboratory field, having utility in clinical practice. It was written by Prof. Ioan Manta (1900-1979) and Alexandru Ciplea (1912-1988), both from the Cluj Faculty of Medicine. The volume was published for the first time in 1944, during the refuge of this Faculty in Sibiu, and for the second time in 1947, in Cluj. Our aim is to make a brief analysis of its structure and to put into evidence the importance of this book for the Romanian laboratory medicine, some techniques (e.g. microscopic techniques) keeping their validity until today. The authors made over 800 detailed presentations about: laboratory sampling and preservation techniques, different types of tests and methods for qualitative and quantitative determinations, techniques to prepare various solutions, microbiological culture media, laboratory stains and reagents, as well as maneuvering of some laboratory equipments. For each method, Manta and Ciplea presented: the principle of working method, reagents required, the working technique, mode of calculation, the result and its interpretation. It also includes some laboratory apparatus descriptions, as well as their mode of working. With regard to the scientific value and to the practical utility of this book, it remains a very important milestone in the Romanian medical literature of the XX-th century.

Current methods of laboratory diagnosis of Chlamydia trachomatis infections.

PubMed Central

Black, C M

1997-01-01

Infections caused by Chlamydia trachomatis are probably the most common sexually transmitted diseases in the United States. Commonly unrecognized and often inadequately treated, chlamydial infections can ascend the reproductive tract and cause pelvic inflammatory disease, which often results in the devastating consequences of infertility, ectopic pregnancy, or chronic pelvic pain. C. trachomatis infections are also known to increase the risk for human immunodeficiency virus infection. The obligate intracellular life cycle of C. trachomatis has traditionally required laboratory diagnostic tests that are technically demanding, labor-intensive, expensive, and difficult to access. In spite of these historical challenges, however, laboratory diagnosis of C. trachomatis has been a rapidly advancing area in which there is presently a wide array of commercial diagnostic technologies, costs, manufacturers. This review describes and compares the diagnostic methods for C. trachomatis infection that are currently approved for use in the United States, including the newest DNA amplification technologies which are yet to be licensed for commercial use. Issues to consider in selecting a test for purposes of screening versus diagnosis based on prevalence, performance, legal, social, and cost issues are also discussed. PMID:8993862

Doing laboratory ethnography: reflections on method in scientific workplaces

PubMed Central

Stephens, Neil; Lewis, Jamie

2017-01-01

Laboratory ethnography extended the social scientist’s gaze into the day-to-day accomplishment of scientific practice. Here we reflect upon our own ethnographies of biomedical scientific workspaces to provoke methodological discussion on the doing of laboratory ethnography. What we provide is less a ‘how to’ guide and more a commentary on what to look for and what to look at. We draw upon our empirical research with stem cell laboratories and animal houses, teams producing robotic surgical tools, musicians sonifying data science, a psychiatric genetics laboratory, and scientists developing laboratory grown meat. We use these cases to example a set of potential ethnographic themes worthy of pursuit: science epistemics and the extended laboratory, the interaction order of scientific work, sensory realms and the rending of science as sensible, conferences as performative sites, and the spaces, places and temporalities of scientific work. PMID:28546784

Characterisation of adhesional properties of lactose carriers using atomic force microscopy.

PubMed

Louey, M D; Mulvaney, P; Stewart, P J

2001-06-01

The atomic force microscopy (AFM) colloid probe technique was investigated as a method for the characterisation of adhesional properties of pharmaceutical powder surfaces. Lactose carriers used in dry powder inhaler (DPI) formulations were chosen for investigation since adhesion between the carrier surface and drug particles has been proposed to affect the dispersion of drug particles. Individual adhesion forces were determined by measuring the detachment forces in air between the colloid probe and the lactose particle surface. The colloid probe consisted of a silica sphere (10 microm diameter) attached to a V-shaped silicon nitride cantilever (spring constant, k=0.42 N/m). Adhesion forces were calculated from individual force-distance curves using Hooke's Law. Individual forces measured at various adhesion sites were observed to be reproducible and stable over 10 min (coefficient of variation, CV below 5%). The adhesion force distribution determined from measurements at multiple sites (n>50) on each sample followed a log-normal relationship (regression coefficient, r(2) ranged between 0.95 and 0.99). This enabled characterisation in terms of the geometric mean adhesion force and a geometric standard deviation (GSD). Significant differences (P<0.001) in adhesion force were observed between samples, ranging from 37.47+/-1.95 to 117.48+/-2.20 nN. This study demonstrates the suitability of AFM as sensitive technique for the characterisation of adhesional properties of pharmaceutical particles.

Characterisation and optimisation of a method for the detection and quantification of atmospherically relevant carbonyl compounds in aqueous medium

NASA Astrophysics Data System (ADS)

Rodigast, M.; Mutzel, A.; Iinuma, Y.; Haferkorn, S.; Herrmann, H.

2015-01-01

Carbonyl compounds are ubiquitous in the atmosphere and either emitted primarily from anthropogenic and biogenic sources or they are produced secondarily from the oxidation of volatile organic compounds (VOC). Despite a number of studies about the quantification of carbonyl compounds a comprehensive description of optimised methods is scarce for the quantification of atmospherically relevant carbonyl compounds. Thus a method was systematically characterised and improved to quantify carbonyl compounds. Quantification with the present method can be carried out for each carbonyl compound sampled in the aqueous phase regardless of their source. The method optimisation was conducted for seven atmospherically relevant carbonyl compounds including acrolein, benzaldehyde, glyoxal, methyl glyoxal, methacrolein, methyl vinyl ketone and 2,3-butanedione. O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) was used as derivatisation reagent and the formed oximes were detected by gas chromatography/mass spectrometry (GC/MS). The main advantage of the improved method presented in this study is the low detection limit in the range of 0.01 and 0.17 μmol L-1 depending on carbonyl compounds. Furthermore best results were found for extraction with dichloromethane for 30 min followed by derivatisation with PFBHA for 24 h with 0.43 mg mL-1 PFBHA at a pH value of 3. The optimised method was evaluated in the present study by the OH radical initiated oxidation of 3-methylbutanone in the aqueous phase. Methyl glyoxal and 2,3-butanedione were found to be oxidation products in the samples with a yield of 2% for methyl glyoxal and 14% for 2,3-butanedione.

Superficially located enlarged lymphoid follicles characterise nodular gastritis.

PubMed

Okamura, Takuma; Sakai, Yasuhiro; Hoshino, Hitomi; Iwaya, Yugo; Tanaka, Eiji; Kobayashi, Motohiro

2015-01-01

Nodular gastritis is a form of chronic Helicobacter pylori gastritis affecting the gastric antrum and characterised endoscopically by the presence of small nodular lesions resembling gooseflesh. It is generally accepted that hyperplasia of lymphoid follicles histologically characterises nodular gastritis; however, quantitative analysis in support of this hypothesis has not been reported. Our goal was to determine whether nodular gastritis is characterised by lymphoid follicle hyperplasia.The number, size, and location of lymphoid follicles in nodular gastritis were determined and those properties compared to samples of atrophic gastritis. The percentages of high endothelial venule (HEV)-like vessels were also evaluated.The number of lymphoid follicles was comparable between nodular and atrophic gastritis; however, follicle size in nodular gastritis was significantly greater than that seen in atrophic gastritis. Moreover, lymphoid follicles in nodular gastritis were positioned more superficially than were those in atrophic gastritis. The percentage of MECA-79 HEV-like vessels was greater in areas with gooseflesh-like lesions in nodular versus atrophic gastritis.Superficially located hyperplastic lymphoid follicles characterise nodular gastritis, and these follicles correspond to gooseflesh-like nodular lesions observed endoscopically. These observations suggest that MECA-79 HEV-like vessels could play at least a partial role in the pathogenesis of nodular gastritis.

Low altitude unmanned aerial vehicle for characterising remediation effectiveness following the FDNPP accident.

PubMed

Martin, P G; Payton, O D; Fardoulis, J S; Richards, D A; Yamashiki, Y; Scott, T B

2016-01-01

On the 12th of March 2011, The Great Tōhoku Earthquake occurred 70 km off the eastern coast of Japan, generating a large 14 m high tsunami. The ensuing catalogue of events over the succeeding 12 d resulted in the release of considerable quantities of radioactive material into the environment. Important to the large-scale remediation of the affected areas is the accurate and high spatial resolution characterisation of contamination, including the verification of decontaminated areas. To enable this, a low altitude unmanned aerial vehicle equipped with a lightweight gamma-spectrometer and height normalisation system was used to produce sub-meter resolution maps of contamination. This system provided a valuable method to examine both contaminated and remediated areas rapidly, whilst greatly reducing the dose received by the operator, typically in localities formerly inaccessible to ground-based survey methods. The characterisation of three sites within Fukushima Prefecture is presented; one remediated (and a site of much previous attention), one un-remediated and a third having been subjected to an alternative method to reduce emitted radiation dose. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

EPA Contract Laboratory Program Statement of Work for Inorganic Superfund Methods Multi-Media, Multi-Concentration ISM02.3

EPA Pesticide Factsheets

This document contains analytical methods for the analysis of metals and cyanide in environmental samples. It also contains contractual requirements for laboratories participating in Superfund's Contract Laboratory Program.

EPA Contract Laboratory Program Statement of Work for Inorganic Superfund Methods Multi-Media, Multi-Concentration ISM02.4

EPA Pesticide Factsheets

This document contains analytical methods for the analysis of metals and cyanide in environmental samples. It also contains contractual requirements for laboratories participating in Superfund's Contract Laboratory Program.

Quantifying bioalbedo: a new physically based model and discussion of empirical methods for characterising biological influence on ice and snow albedo

NASA Astrophysics Data System (ADS)

Cook, Joseph M.; Hodson, Andrew J.; Gardner, Alex S.; Flanner, Mark; Tedstone, Andrew J.; Williamson, Christopher; Irvine-Fynn, Tristram D. L.; Nilsson, Johan; Bryant, Robert; Tranter, Martyn

2017-11-01

The darkening effects of biological impurities on ice and snow have been recognised as a control on the surface energy balance of terrestrial snow, sea ice, glaciers and ice sheets. With a heightened interest in understanding the impacts of a changing climate on snow and ice processes, quantifying the impact of biological impurities on ice and snow albedo (bioalbedo) and its evolution through time is a rapidly growing field of research. However, rigorous quantification of bioalbedo has remained elusive because of difficulties in isolating the biological contribution to ice albedo from that of inorganic impurities and the variable optical properties of the ice itself. For this reason, isolation of the biological signature in reflectance data obtained from aerial/orbital platforms has not been achieved, even when ground-based biological measurements have been available. This paper provides the cell-specific optical properties that are required to model the spectral signatures and broadband darkening of ice. Applying radiative transfer theory, these properties provide the physical basis needed to link biological and glaciological ground measurements with remotely sensed reflectance data. Using these new capabilities we confirm that biological impurities can influence ice albedo, then we identify 10 challenges to the measurement of bioalbedo in the field with the aim of improving future experimental designs to better quantify bioalbedo feedbacks. These challenges are (1) ambiguity in terminology, (2) characterising snow or ice optical properties, (3) characterising solar irradiance, (4) determining optical properties of cells, (5) measuring biomass, (6) characterising vertical distribution of cells, (7) characterising abiotic impurities, (8) surface anisotropy, (9) measuring indirect albedo feedbacks, and (10) measurement and instrument configurations. This paper aims to provide a broad audience of glaciologists and biologists with an overview of radiative

Development and characterisation of hybrid polysaccharide membranes for dehydration processes.

PubMed

Meireles, Inês T; Huertas, Rosa M; Torres, Cristiana A V; Coelhoso, Isabel M; Crespo, João G

2018-07-01

The purpose of this work is the development and characterisation of new hybrid polysaccharide (FucoPol) membranes. These membranes were prepared by incorporation of a SiO 2 network homogeneously dispersed by using a sol-gel method with GPTMS as a crosslinker silica precursor. They were further crosslinked with CaCl 2 for reinforcement of mechanical properties and improvement of their permeation performance. They were characterised in terms of their structural, mechanical and thermal properties. They presented a dense and homogeneous structure, resistant to deformation, with a Tg of 43 °C and a thermal decomposition between 240 and 251 °C. The hybrid FucoPol membranes were tested for ethanol dehydration by pervaporation and also for nitrogen dehydration. They exhibited high water selectivity values, similar to PERVAP ® 4101, however they lost their stability when exposed to solutions of 10.0 wt.% water in ethanol. In contrast, these membranes were stable when applied in N 2 dehydration, leading to reproducible performance and very high water selectivities. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Language Laboratory.

ERIC Educational Resources Information Center

Hughes, John P.

Concepts pertaining to the language laboratory are clarified for the layman unfamiliar with recent educational developments in foreign language instruction. These include discussion of: (1) language laboratory components and functions, (2) techniques used in the laboratory, (3) new linguistic methods, (4) laboratory exercises, (5) traditional…

Characterisation of the n-colour printing process using the spot colour overprint model.

PubMed

Deshpande, Kiran; Green, Phil; Pointer, Michael R

2014-12-29

This paper is aimed at reproducing the solid spot colours using the n-colour separation. A simplified numerical method, called as the spot colour overprint (SCOP) model, was used for characterising the n-colour printing process. This model was originally developed for estimating the spot colour overprints. It was extended to be used as a generic forward characterisation model for the n-colour printing process. The inverse printer model based on the look-up table was implemented to obtain the colour separation for n-colour printing process. Finally the real-world spot colours were reproduced using 7-colour separation on lithographic offset printing process. The colours printed with 7 inks were compared against the original spot colours to evaluate the accuracy. The results show good accuracy with the mean CIEDE2000 value between the target colours and the printed colours of 2.06. The proposed method can be used successfully to reproduce the spot colours, which can potentially save significant time and cost in the printing and packaging industry.

Culture-independent genomic characterisation of Candidatus Chlamydia sanzinia, a novel uncultivated bacterium infecting snakes.

PubMed

Taylor-Brown, Alyce; Bachmann, Nathan L; Borel, Nicole; Polkinghorne, Adam

2016-09-05

Recent molecular studies have revealed considerably more diversity in the phylum Chlamydiae than was previously thought. Evidence is growing that many of these novel chlamydiae may be important pathogens in humans and animals. A significant barrier to characterising these novel chlamydiae is the requirement for culturing. We recently identified a range of novel uncultured chlamydiae in captive snakes in Switzerland, however, nothing is known about their biology. Using a metagenomics approach, the aim of this study was to characterise the genome of a novel chlamydial taxon from the choana of a captive snake. In doing so, we propose a new candidate species in the genus Chlamydia (Candidatus Chlamydia sanzinia) and reveal new information about the biological diversity of this important group of pathogens. We identified two chlamydial genomic contigs: a 1,113,073 bp contig, and a 7,504 bp contig, representing the chromosome and plasmid of Ca. Chlamydia sanzinia strain 2742-308, respectively. The 998 predicted coding regions include an expanded repertoire of outer membrane proteins (Pmps and Omps), some of which exhibited frameshift mutations, as well as several chlamydial virulence factors such as the translocating actin-recruitment phosphoprotein (Tarp) and macrophage inhibition potentiator (Mip). A suite of putative inclusion membrane proteins were also predicted. Notably, no evidence of a traditional chlamydial plasticity zone was identified. Phylogenetically, Ca. Chlamydia sanzinia forms a clade with C. pneumoniae and C. pecorum, distinct from former "Chlamydophila" species. Genomic characterisation of a novel uncultured chlamydiae from the first reptilian host has expanded our understanding of the diversity and biology of a genus that was thought to be the most well-characterised in this unique phylum. It is anticipated that this method will be suitable for characterisation of other novel chlamydiae.

Materials Characterisation and Analysis for Flow Simulation of Liquid Resin Infusion

NASA Astrophysics Data System (ADS)

Sirtautas, J.; Pickett, A. K.; George, A.

2015-06-01

Liquid Resin Infusion (LRI) processes including VARI and VARTM have received increasing attention in recent years, particularly for infusion of large parts, or for low volume production. This method avoids the need for costly matched metal tooling as used in Resin Transfer Moulding (RTM) and can provide fast infusion if used in combination with flow media. Full material characterisation for LRI analysis requires models for three dimensional fabric permeability as a function of fibre volume content, fabric through-thickness compliance as a function of resin pressure, flow media permeability and resin viscosity. The characterisation of fabric relaxation during infusion is usually determined from cyclic compaction tests on saturated fabrics. This work presents an alternative method to determine the compressibility by using LRI flow simulation and fitting a model to experimental thickness measurements during LRI. The flow media is usually assumed to have isotropic permeability, but this work shows greater simulation accuracy from combining the flow media with separation plies as a combined orthotropic material. The permeability of this combined media can also be determined by fitting the model with simulation to LRI flow measurements. The constitutive models and the finite element solution were validated by simulation of the infusion of a complex aerospace demonstrator part.

Accuracy of p53 Codon 72 Polymorphism Status Determined by Multiple Laboratory Methods: A Latent Class Model Analysis

PubMed Central

Walter, Stephen D.; Riddell, Corinne A.; Rabachini, Tatiana; Villa, Luisa L.; Franco, Eduardo L.

2013-01-01

Introduction Studies on the association of a polymorphism in codon 72 of the p53 tumour suppressor gene (rs1042522) with cervical neoplasia have inconsistent results. While several methods for genotyping p53 exist, they vary in accuracy and are often discrepant. Methods We used latent class models (LCM) to examine the accuracy of six methods for p53 determination, all conducted by the same laboratory. We also examined the association of p53 with cytological cervical abnormalities, recognising potential test inaccuracy. Results Pairwise disagreement between laboratory methods occurred approximately 10% of the time. Given the estimated true p53 status of each woman, we found that each laboratory method is most likely to classify a woman to her correct status. Arg/Arg women had the highest risk of squamous intraepithelial lesions (SIL). Test accuracy was independent of cytology. There was no strong evidence for correlations of test errors. Discussion Empirical analyses ignore possible laboratory errors, and so are inherently biased, but test accuracy estimated by the LCM approach is unbiased when model assumptions are met. LCM analysis avoids ambiguities arising from empirical test discrepancies, obviating the need to regard any of the methods as a “gold” standard measurement. The methods we presented here to analyse the p53 data can be applied in many other situations where multiple tests exist, but where none of them is a gold standard. PMID:23441193

A Profilometry-Based Dentifrice Abrasion Method for V8 Brushing Machines Part III: Multi-Laboratory Validation Testing of RDA-PE.

PubMed

Schneiderman, Eva; Colón, Ellen L; White, Donald J; Schemehorn, Bruce; Ganovsky, Tara; Haider, Amir; Garcia-Godoy, Franklin; Morrow, Brian R; Srimaneepong, Viritpon; Chumprasert, Sujin

2017-09-01

We have previously reported on progress toward the refinement of profilometry-based abrasivity testing of dentifrices using a V8 brushing machine and tactile or optical measurement of dentin wear. The general application of this technique may be advanced by demonstration of successful inter-laboratory confirmation of the method. The objective of this study was to explore the capability of different laboratories in the assessment of dentifrice abrasivity using a profilometry-based evaluation technique developed in our Mason laboratories. In addition, we wanted to assess the interchangeability of human and bovine specimens. Participating laboratories were instructed in methods associated with Radioactive Dentin Abrasivity-Profilometry Equivalent (RDA-PE) evaluation, including site visits to discuss critical elements of specimen preparation, masking, profilometry scanning, and procedures. Laboratories were likewise instructed on the requirement for demonstration of proportional linearity as a key condition for validation of the technique. Laboratories were provided with four test dentifrices, blinded for testing, with a broad range of abrasivity. In each laboratory, a calibration curve was developed for varying V8 brushing strokes (0, 4,000, and 10,000 strokes) with the ISO abrasive standard. Proportional linearity was determined as the ratio of standard abrasion mean depths created with 4,000 and 10,000 strokes (2.5 fold differences). Criteria for successful calibration within the method (established in our Mason laboratory) was set at proportional linearity = 2.5 ± 0.3. RDA-PE was compared to Radiotracer RDA for the four test dentifrices, with the latter obtained by averages from three independent Radiotracer RDA sites. Individual laboratories and their results were compared by 1) proportional linearity and 2) acquired RDA-PE values for test pastes. Five sites participated in the study. One site did not pass proportional linearity objectives. Data for this site are

Multi-laboratory survey of qPCR enterococci analysis method performance

EPA Pesticide Factsheets

Quantitative polymerase chain reaction (qPCR) has become a frequently used technique for quantifying enterococci in recreational surface waters, but there are several methodological options. Here we evaluated how three method permutations, type of mastermix, sample extract dilution and use of controls in results calculation, affect method reliability among multiple laboratories with respect to sample interference. Multiple samples from each of 22 sites representing an array of habitat types were analyzed using EPA Method 1611 and 1609 reagents with full strength and five-fold diluted extracts. The presence of interference was assessed three ways: using sample processing and PCR amplifications controls; consistency of results across extract dilutions; and relative recovery of target genes from spiked enterococci in water sample compared to control matrices with acceptable recovery defined as 50 to 200%. Method 1609, which is based on an environmental mastermix, was found to be superior to Method 1611, which is based on a universal mastermix. Method 1611 had over a 40% control assay failure rate with undiluted extracts and a 6% failure rate with diluted extracts. Method 1609 failed in only 11% and 3% of undiluted and diluted extracts analyses. Use of sample processing control assay results in the delta-delta Ct method for calculating relative target gene recoveries increased the number of acceptable recovery results. Delta-delta tended to bias recoveries fr

Fabrication and characterisation of nanocrystalline graphite MEMS resonators using a geometric design to control buckling

NASA Astrophysics Data System (ADS)

Fishlock, S. J.; O'Shea, S. J.; McBride, J. W.; Chong, H. M. H.; Pu, S. H.

2017-09-01

The simulation, fabrication and characterisation of nanographite MEMS resonators is reported in this paper. The deposition of nanographite is achieved using plasma-enhanced chemical vapour deposition directly onto numerous substrates such as commercial silicon wafers. As a result, many of the reliability issues of devices based on transferred graphene are avoided. The fabrication of the resonators is presented along with a simple undercutting method to overcome buckling, by changing the effective stress of the structure from ~436 MPa compressive, to ~13 MPa tensile. The characterisation of the resonators using electrostatic actuation and laser Doppler vibrometry is reported, demonstrating resonator frequencies from 5-640 kHz and quality factor above 1819 in vacuum obtained.

Materials and Methods for Streamlined Laboratory Analysis of Environmental Samples, FY 2016 Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Addleman, Raymond S.; Naes, Benjamin E.; McNamara, Bruce K.

The International Atomic Energy Agency (IAEA) relies upon laboratory analysis of environmental samples (typically referred to as “swipes”) collected during on-site inspections of safeguarded facilities to support the detection and deterrence of undeclared activities. Unfortunately, chemical processing and assay of the samples is slow and expensive. A rapid, effective, and simple extraction process and analysis method is needed to provide certified results with improved timeliness at reduced costs (principally in the form of reduced labor), while maintaining or improving sensitivity and efficacy. To address these safeguard needs the Pacific Northwest National Laboratory (PNNL) explored and demonstrated improved methods for environmentalmore » sample (ES) analysis. Improvements for both bulk and particle analysis were explored. To facilitate continuity and adoption, the new sampling materials and processing methods will be compatible with existing IAEA protocols for ES analysis. PNNL collaborated with Oak Ridge National Laboratory (ORNL), which performed independent validation of the new bulk analysis methods and compared performance to traditional IAEA’s Network of Analytical Laboratories (NWAL) protocol. ORNL efforts are reported separately. This report describes PNNL’s FY 2016 progress, which was focused on analytical application supporting environmental monitoring of uranium enrichment plants and nuclear fuel processing. In the future the technology could be applied to other safeguard applications and analytes related to fuel manufacturing, reprocessing, etc. PNNL’s FY 2016 efforts were broken into two tasks and a summary of progress, accomplishments and highlights are provided below. Principal progress and accomplishments on Task 1, Optimize Materials and Methods for ICP-MS Environmental Sample Analysis, are listed below. • Completed initial procedure for rapid uranium extraction from ES swipes based upon carbonate-peroxide chemistry (delivered to

An empirical review of antimalarial quality field surveys: the importance of characterising outcomes.

PubMed

Grech, James; Robertson, James; Thomas, Jackson; Cooper, Gabrielle; Naunton, Mark; Kelly, Tamsin

2018-01-05

For decades, thousands of people have been dying from malaria infections because of poor-quality medicines (PQMs). While numerous efforts have been initiated to reduce their presence, PQMs are still risking the lives of those seeking treatment. This review addresses the importance of characterising results of antimalarial medicine field surveys based upon the agreement of clearly defined definitions. Medicines found to be of poor quality can be falsified or counterfeit, substandard or degraded. The distinction between these categories is important as each category requires a different countermeasure. To observe the current trends in the reporting of field surveys, a systematic literature search of six academic databases resulted in the quantitative analysis of 61 full-text journal articles. Information including sample size, sampling method, geographical regions, analytical techniques, and characterisation conclusions was observed for each. The lack of an accepted uniform reporting system has resulted in varying, incomplete reports, which may not include important information that helps form effective countermeasures. The programmes influencing medicine quality such as prequalification, procurement services, awareness and education can be supported with the information derived from characterised results. The implementation of checklists such as the Medicine Quality Assessment Reporting Guidelines will further strengthen the battle against poor-quality antimalarials. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparative Study in Laboratory Rats to Validate Sperm Quality Methods and Endpoints

NASA Technical Reports Server (NTRS)

Price, W. A.; Briggs, G. B.; Alexander, W. K.; Still, K. R.; Grasman, K. A.

2000-01-01

Abstract The Naval Health Research Center, Detachment (Toxicology) performs toxicity studies in laboratory animals to characterize the risk of exposure to chemicals of Navy interest. Research was conducted at the Toxicology Detachment at WPAFB, OH in collaboration with Wright State University, Department of Biological Sciences for the validation of new bioassay methods for evaluating reproductive toxicity. The Hamilton Thorne sperm analyzer was used to evaluate sperm damage produced by exposure to a known testicular toxic agent, methoxyacetic acid and by inhalation exposure to JP-8 and JP-5 in laboratory rats. Sperm quality parameters were evaluated (sperm concentration, motility, and morphology) to provide evidence of sperm damage. The Hamilton Thorne sperm analyzer utilizes a DNA specific fluorescent stain (similar to flow cytometry) and digitized optical computer analysis to detect sperm cell damage. The computer assisted sperm analysis (CASA) is a more rapid, robust, predictive and sensitive method for characterizing reproductive toxicity. The results presented in this poster report validation information showing exposure to methoxyacetic acid causes reproductive toxicity and inhalation exposure to JP-8 and JP-5 had no significant effects. The CASA method detects early changes that result in reproductive deficits and these data will be used in a continuing program to characterize the toxicity of chemicals, and combinations of chemicals, of military interest to formulate permissible exposure limits.

Educational area for learning of optics and technologies: union of open laboratories of ideas, methods and practices (OLIMP)

NASA Astrophysics Data System (ADS)

Ivashchenko, Maksim; Bodrov, Kirill; Tolstoba, Nadezhda

2016-09-01

The paper deals with the concept of creating the union of Open Laboratories of Ideas, Methods and Practices (OLIMP). It describes the structure designed to simplify the relationship, such as business incubators, start-up accelerators, small innovative enterprises, fabrication laboratories and student centers. We consider their advantages and disadvantages for the specific audience of students and enthusiasts who do not have funding for their own projects. The experience of interaction between the Open Laboratories of Ideas, Methods and Practices and the Student Research Laboratory for Optical Engineering shows the relative impact of structures on each other and the value of using such interaction in the learning process. The paper also addresses issues such as: the motivation of students, enthusiasm for the direction the lab participants identify and maintain the initiatives, profiling in the design, scientific, commercial, social sphere.

Revising laboratory work: sociological perspectives on the science classroom

NASA Astrophysics Data System (ADS)

Jobér, Anna

2017-09-01

This study uses sociological perspectives to analyse one of the core practices in science education: schoolchildren's and students' laboratory work. Applying an ethnographic approach to the laboratory work done by pupils at a Swedish compulsory school, data were generated through observations, field notes, interviews, and a questionnaire. The pupils, ages 14 and 15, were observed as they took a 5-week physics unit (specifically, mechanics). The analysis shows that the episodes of laboratory work could be filled with curiosity and exciting challenges; however, another picture emerged when sociological concepts and notions were applied to what is a very common way of working in the classroom. Laboratory work is characterised as a social activity that is expected to be organised as a group activity. This entails groups becoming, to some extent, `safe havens' for the pupils. On the other hand, this way of working in groups required pupils to subject to the groups and the peer effect, sometimes undermining their chances to learn and perform better. In addition, the practice of working in groups when doing laboratory work left some pupils and the teacher blaming themselves, even though the outcome of the learning situation was a result of a complex interplay of social processes. This article suggests a stronger emphasis on the contradictions and consequences of the science subjects, which are strongly influenced by their socio-historical legacy.

Characterisation and detection of spoilage mould responsible for black spot in dry-cured fermented sausages.

PubMed

Lozano-Ojalvo, Daniel; Rodríguez, Alicia; Cordero, Mirian; Bernáldez, Victoria; Reyes-Prieto, Mariana; Córdoba, Juan J

2015-02-01

Moulds responsible for black spot spoilage of dry-cured fermented sausages were characterised. For this purpose, samples were taken from those dry-cured fermented sausages which showed black spot alteration. Most of the mould strains were first tentatively identified as Penicillium spp. due to their morphological characteristics in different culture conditions, with one strain as Cladosporium sp. The Cladosporium strain was the only one which provoked blackening in culture media. This strain was further characterised by sequencing of ITS1-5.8S-ITS2 rRNA and β-tubulin genes. This mould strain was able to reproduce black spot formation in dry-cured fermented sausage 'salchichón' throughout the ripening process. In addition, a specific and sensitive real-time PCR method was also developed to detect Cladosporium oxysporum responsible for the black spot formation in sausages. This method could be of great interest for the meat industry to detect samples contaminated with this mould before spoilage of product avoiding economic losses for this sector.

A method to evaluate performance reliability of individual subjects in laboratory research applied to work settings.

DOT National Transportation Integrated Search

1978-10-01

This report presents a method that may be used to evaluate the reliability of performance of individual subjects, particularly in applied laboratory research. The method is based on analysis of variance of a tasks-by-subjects data matrix, with all sc...

Electro-Optic Characterisation of Extremely Wide Bandwidth Electrical Signals

DTIC Science & Technology

1993-02-01

In this report an ultrafast electro - optic sampling system suitable for applications such as device characterisation is described. The aperture time of the sampler is calculated to be about 290 fs, implying an attainable device bandwidth in excess of 300 GHz. The sampler was characterised using a test pulse with approximately 12 GHz of frequency content, and the results compared to those obtained from an 18 GHz digital sampling oscilloscope. Signal Processing, Bandwidth, Frequencies, Oscilloscopes.

3-Dimensional and Interactive Istanbul University Virtual Laboratory Based on Active Learning Methods

ERIC Educational Resources Information Center

Ince, Elif; Kirbaslar, Fatma Gulay; Yolcu, Ergun; Aslan, Ayse Esra; Kayacan, Zeynep Cigdem; Alkan Olsson, Johanna; Akbasli, Ayse Ceylan; Aytekin, Mesut; Bauer, Thomas; Charalambis, Dimitris; Gunes, Zeliha Ozsoy; Kandemir, Ceyhan; Sari, Umit; Turkoglu, Suleyman; Yaman, Yavuz; Yolcu, Ozgu

2014-01-01

The purpose of this study is to develop a 3-dimensional interactive multi-user and multi-admin IUVIRLAB featuring active learning methods and techniques for university students and to introduce the Virtual Laboratory of Istanbul University and to show effects of IUVIRLAB on students' attitudes on communication skills and IUVIRLAB. Although there…

Smart Aquifer Characterisation validated using Information Theory and Cost benefit analysis

NASA Astrophysics Data System (ADS)

Moore, Catherine

2016-04-01

The field data acquisition required to characterise aquifer systems are time consuming and expensive. Decisions regarding field testing, the type of field measurements to make and the spatial and temporal resolution of measurements have significant cost repercussions and impact the accuracy of various predictive simulations. The Smart Aquifer Characterisation (SAC) research programme (New Zealand (NZ)) addresses this issue by assembling and validating a suite of innovative methods for characterising groundwater systems at the large, regional and national scales. The primary outcome is a suite of cost effective tools and procedures provided to resource managers to advance the understanding and management of groundwater systems and thereby assist decision makers and communities in the management of their groundwater resources, including the setting of land use limits that protect fresh water flows and quality and the ecosystems dependent on that fresh water. The programme has focused novel investigation approaches including the use of geophysics, satellite remote sensing, temperature sensing and age dating. The SMART (Save Money And Reduce Time) aspect of the programme emphasises techniques that use these passive cost effective data sources to characterise groundwater systems at both the aquifer and the national scale by: • Determination of aquifer hydraulic properties • Determination of aquifer dimensions • Quantification of fluxes between ground waters and surface water • Groundwater age dating These methods allow either a lower cost method for estimating these properties and fluxes, or a greater spatial and temporal coverage for the same cost. To demonstrate the cost effectiveness of the methods a 'data worth' analysis is undertaken. The data worth method involves quantification of the utility of observation data in terms of how much it reduces the uncertainty of model parameters and decision focussed predictions which depend on these parameters. Such

Iterative outlier removal: A method for identifying outliers in laboratory recalibration studies

PubMed Central

Parrinello, Christina M.; Grams, Morgan E.; Sang, Yingying; Couper, David; Wruck, Lisa M.; Li, Danni; Eckfeldt, John H.; Selvin, Elizabeth; Coresh, Josef

2016-01-01

Background Extreme values that arise for any reason, including through non-laboratory measurement procedure-related processes (inadequate mixing, evaporation, mislabeling), lead to outliers and inflate errors in recalibration studies. We present an approach termed iterative outlier removal (IOR) for identifying such outliers. Methods We previously identified substantial laboratory drift in uric acid measurements in the Atherosclerosis Risk in Communities (ARIC) Study over time. Serum uric acid was originally measured in 1990–92 on a Coulter DACOS instrument using an uricase-based measurement procedure. To recalibrate previous measured concentrations to a newer enzymatic colorimetric measurement procedure, uric acid was re-measured in 200 participants from stored plasma in 2011–13 on a Beckman Olympus 480 autoanalyzer. To conduct IOR, we excluded data points >3 standard deviations (SDs) from the mean difference. We continued this process using the resulting data until no outliers remained. Results IOR detected more outliers and yielded greater precision in simulation. The original mean difference (SD) in uric acid was 1.25 (0.62) mg/dL. After four iterations, 9 outliers were excluded, and the mean difference (SD) was 1.23 (0.45) mg/dL. Conducting only one round of outlier removal (standard approach) would have excluded 4 outliers (mean difference [SD] = 1.22 [0.51] mg/dL). Applying the recalibration (derived from Deming regression) from each approach to the original measurements, the prevalence of hyperuricemia (>7 mg/dL) was 28.5% before IOR and 8.5% after IOR. Conclusion IOR is a useful method for removal of extreme outliers irrelevant to recalibrating laboratory measurements, and identifies more extraneous outliers than the standard approach. PMID:27197675

Optimized star sensors laboratory calibration method using a regularization neural network.

PubMed

Zhang, Chengfen; Niu, Yanxiong; Zhang, Hao; Lu, Jiazhen

2018-02-10

High-precision ground calibration is essential to ensure the performance of star sensors. However, the complex distortion and multi-error coupling have brought great difficulties to traditional calibration methods, especially for large field of view (FOV) star sensors. Although increasing the complexity of models is an effective way to improve the calibration accuracy, it significantly increases the demand for calibration data. In order to achieve high-precision calibration of star sensors with large FOV, a novel laboratory calibration method based on a regularization neural network is proposed. A multi-layer structure neural network is designed to represent the mapping of the star vector and the corresponding star point coordinate directly. To ensure the generalization performance of the network, regularization strategies are incorporated into the net structure and the training algorithm. Simulation and experiment results demonstrate that the proposed method can achieve high precision with less calibration data and without any other priori information. Compared with traditional methods, the calibration error of the star sensor decreased by about 30%. The proposed method can satisfy the precision requirement for large FOV star sensors.

Designing a ruggedisation lab to characterise materials for harsh environments.

PubMed

Frazzette, Nicholas; Jethva, Janak; Mehta, Khanjan; Stapleton, Joshua J; Randall, Clive

Designing products for use in developing countries presents a unique set of challenges including harsh operating environments, costly repairs and maintenance, and users with varying degrees of education and device familiarity. For products to be robust, adaptable and durable, they need to be ruggedised for environmental factors such as high temperature and humidity as well as different operational conditions such as shock and chemical exposure. The product characterisation and ruggedisation processes require specific expertise and resources that are seldom available outside of large corporations and elite national research labs. There is no standardised process since product needs strongly depend on the context and user base, making it particularly onerous for underfunded start-ups and academic groups. Standardised protocols that identify essential lab testing regimens for specific contexts and user groups can complement field-testing and accelerate the product development process while reducing costs. This article synthesises current methods and strategies for product testing employed by large corporations as well as defence-related entities. A technological and organisational framework for a service-for-fee product characterisation and ruggedisation lab that reduces costs and shortens the timespan from product invention to commercial launch in harsh settings is presented.

Economic Education Laboratory: Initiating a Meaningful Economic Learning through Laboratory

ERIC Educational Resources Information Center

Noviani, Leny; Soetjipto, Budi Eko; Sabandi, Muhammad

2015-01-01

Laboratory is considered as one of the resources in supporting the learning process. The laboratory can be used as facilities to deepen the concepts, learning methods and enriching students' knowledge and skills. Learning process by utilizing the laboratory facilities can help lecturers and students in grasping the concept easily, constructing the…

Impact of cultivation on characterisation of species composition of soil bacterial communities.

PubMed

McCaig, A E.; Grayston, S J.; Prosser, J I.; Glover, L A.

2001-03-01

The species composition of culturable bacteria in Scottish grassland soils was investigated using a combination of Biolog and 16S rDNA analysis for characterisation of isolates. The inclusion of a molecular approach allowed direct comparison of sequences from culturable bacteria with sequences obtained during analysis of DNA extracted directly from the same soil samples. Bacterial strains were isolated on Pseudomonas isolation agar (PIA), a selective medium, and on tryptone soya agar (TSA), a general laboratory medium. In total, 12 and 21 morphologically different bacterial cultures were isolated on PIA and TSA, respectively. Biolog and sequencing placed PIA isolates in the same taxonomic groups, the majority of cultures belonging to the Pseudomonas (sensu stricto) group. However, analysis of 16S rDNA sequences proved more efficient than Biolog for characterising TSA isolates due to limitations of the Microlog database for identifying environmental bacteria. In general, 16S rDNA sequences from TSA isolates showed high similarities to cultured species represented in sequence databases, although TSA-8 showed only 92.5% similarity to the nearest relative, Bacillus insolitus. In general, there was very little overlap between the culturable and uncultured bacterial communities, although two sequences, PIA-2 and TSA-13, showed >99% similarity to soil clones. A cloning step was included prior to sequence analysis of two isolates, TSA-5 and TSA-14, and analysis of several clones confirmed that these cultures comprised at least four and three sequence types, respectively. All isolate clones were most closely related to uncultured bacteria, with clone TSA-5.1 showing 99.8% similarity to a sequence amplified directly from the same soil sample. Interestingly, one clone, TSA-5.4, clustered within a novel group comprising only uncultured sequences. This group, which is associated with the novel, deep-branching Acidobacterium capsulatum lineage, also included clones isolated

The growth and perfection of β-cyclotetramethylene-tetranitramine (HMX) studied by laboratory and synchrotron X-ray topography

NASA Astrophysics Data System (ADS)

Gallagher, H. G.; Sherwood, J. N.; Vrcelj, R. M.

2017-10-01

An examination has been made of the defect structure of crystals of the energetic material β-cyclotetramethylene-tetranitramine (HMX) using both Laboratory (Lang method) and Synchrotron (Bragg Reflection and Laue method) techniques. The results of the three methods are compared with particular attention to the influence of potential radiation damage caused to the samples by the latter, more energetic, technique. The comparison shows that both techniques can be confidently used to evaluate the defect structures yielding closely similar results. The results show that, even under the relatively casual preparative methods used (slow evaporation of unstirred solutions at constant temperature), HMX crystals of high perfection can be produced. The crystals show well defined bulk defect structures characteristic of organic materials in general: growth dislocations, twins, growth sector boundaries, growth banding and solvent inclusions. The distribution of the defects in specific samples is correlated with the morphological variation of the grown crystals. The results show promise for the further evaluation and characterisation of the structure and properties of dislocations and other defects and their involvement in mechanical and energetic processes in this material.

cp-R, an interface the R programming language for clinical laboratory method comparisons.

PubMed

Holmes, Daniel T

2015-02-01

Clinical scientists frequently need to compare two different bioanalytical methods as part of assay validation/monitoring. As a matter necessity, regression methods for quantitative comparison in clinical chemistry, hematology and other clinical laboratory disciplines must allow for error in both the x and y variables. Traditionally the methods popularized by 1) Deming and 2) Passing and Bablok have been recommended. While commercial tools exist, no simple open source tool is available. The purpose of this work was to develop and entirely open-source GUI-driven program for bioanalytical method comparisons capable of performing these regression methods and able to produce highly customized graphical output. The GUI is written in python and PyQt4 with R scripts performing regression and graphical functions. The program can be run from source code or as a pre-compiled binary executable. The software performs three forms of regression and offers weighting where applicable. Confidence bands of the regression are calculated using bootstrapping for Deming and Passing Bablok methods. Users can customize regression plots according to the tools available in R and can produced output in any of: jpg, png, tiff, bmp at any desired resolution or ps and pdf vector formats. Bland Altman plots and some regression diagnostic plots are also generated. Correctness of regression parameter estimates was confirmed against existing R packages. The program allows for rapid and highly customizable graphical output capable of conforming to the publication requirements of any clinical chemistry journal. Quick method comparisons can also be performed and cut and paste into spreadsheet or word processing applications. We present a simple and intuitive open source tool for quantitative method comparison in a clinical laboratory environment. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Exploiting Continuous Scanning Laser Doppler Vibrometry in timing belt dynamic characterisation

NASA Astrophysics Data System (ADS)

Chiariotti, P.; Martarelli, M.; Castellini, P.

2017-03-01

Dynamic behaviour of timing belts has always interested the engineering community over the years. Nowadays, there are several numerical methods to predict the dynamics of these systems. However, the tuning of such models by experimental approaches still represents an issue: an accurate characterisation does require a measurement in operating conditions since the belt mounting condition might severely affect its dynamic behaviour. Moreover, since the belt is constantly moving during running conditions, non-contact measurement methods are needed. Laser Doppler Vibrometry (LDV) and imaging techniques do represent valid candidates for this purpose. This paper aims at describing the use of Continuous Scanning LDV (CSLDV) as a tool for the dynamic characterisation of timing belts in IC (Internal Combustion) engines (cylinder head). The high-spatial resolution data that can be collected in short testing time makes CSLDV highly suitable for such application. The measurement on a moving surface, however, represents a challenge for CSLDV. The paper discusses how the belt in-plane speed influences CSLDV signal and how an order-based multi-harmonic excitation might affect the recovery of Operational Deflection Shapes in a CSLDV test. A comparison with a standard Discrete Scanning LDV measurement is also given in order to show that a CSLDV test, if well designed, can indeed provide the same amount of information in a drastically reduced amount of time.

Searching for and characterising extrasolar Earth-like planets and moons

NASA Astrophysics Data System (ADS)

Schneider, Jean

2002-10-01

The physical bases of the detection and characterisation of extrasolar Earth-like planets and moons in the reflected light and thermal emission regimes are reviewed. They both have their advantages and disadvantages, including artefacts, in the determination of planet physical parameters (mass, size, albedo, surface and atmospheric conditions etc.). After a short panorama of detection methods and the first findings, new perspectives for these different aspects are also presented. Finally brief account of the ground based programmes and space-based projects and their potentialities for Earth-like planets is made and discussed.

Preparation of a sewage sludge laboratory quality control material for butyltin compounds and their determination by isotope-dilution mass spectrometry.

PubMed

Zuliani, Tea; Milačič, Radmila; Ščančar, Janez

2012-05-01

The characterisation of a laboratory quality control material (QCM) for dibutyltin (DBT) and tributyltin (TBT) in sewage sludge is described. The reference values were determined by the use of two different types of isotope-dilution mass spectrometry: gas chromatography-mass spectrometry and gas chromatography-inductively coupled plasma mass spectrometry. To avoid possible analytical errors such as non-quantitative extraction and species degradation during sample preparation, different extraction methods were tested (microwave- and ultrasound-assisted extraction and mechanical stirring). The reference values were based on the unweighted means of results from the homogenisation and characterisation studies. The reference values obtained were 1,553 ± 87 and 534 ± 38 ng Sn g(-1) for DBT and TBT, respectively. In the uncertainty budget estimation, the sample inhomogeneity and between-method imprecision were taken into account. The concentrations of DBT and TBT in QCM are similar to those in the harbour sediment certified reference material PACS-2. Likewise, the levels of DBT and TBT are in the range of these compounds normally present in sewage sludge worldwide. In the future, the QCM will be used for an intercomparison study on DBT and TBT in sewage sludge, and as a day-to-day QCM during studies concerning the application of sewage sludge as an additive to artificial soil or as a raw material in civil engineering construction.

Expanding Clinical Laboratory Tobacco Product Evaluation Methods to Loose-leaf Tobacco Vaporizers

PubMed Central

Lopez, Alexa A.; Hiler, Marzena; Maloney, Sarah; Eissenberg, Thomas; Breland, Alison

2016-01-01

Background Novel tobacco products entering the US market include electronic cigarettes (ECIGs) and products advertised to “heat, not burn” tobacco. There is a growing literature regarding the acute effects of ECIGs. Less is known about “heat, not burn” products. This study’s purpose was to expand existing clinical laboratory methods to examine, in cigarette smokers, the acute effects of a “heat, not burn” “loose-leaf tobacco vaporizer” (LLTV). Methods Plasma nicotine and breath carbon monoxide (CO) concentration and tobacco abstinence symptom severity were measured before and after two 10-puff (30-sec interpuff interval) product use bouts separated by 60 minutes. LLTV effects were compared to participants’ own brand (OB) cigarettes and an ECIG (3.3 V; 1.5 Ohm; 18 mg/ml nicotine). Results Relative to OB, LLTV increased plasma nicotine concentration to a lesser degree, did not increase CO, and appeared to not reduce abstinence symptoms as effectively. Relative to ECIG, LLTV nicotine and CO delivery and abstinence symptom suppression did not differ. Participants reported that both the LLTV and ECIG were significantly less satisfying than OB. Conclusions Results demonstrate that LLTVs are capable of delivering nicotine and suppressing tobacco abstinence symptoms partially; acute effects of these products can be evaluated using existing clinical laboratory methods. Results can inform tobacco product regulation and may be predictive of the extent that these products have the potential to benefit or harm overall public health. PMID:27768968

Short communication: Development of a rapid laboratory method to polymerize lactose to nondigestible carbohydrates.

PubMed

Kuechel, A F; Schoenfuss, T C

2018-04-01

Nondigestible carbohydrates with a degree of polymerization between 3 and 10 (oligosaccharides) are commonly used as dietary fiber ingredients in the food industry, once they have been confirmed to have positive effects on human health by regulatory authorities. These carbohydrates are produced through chemical or enzymatic synthesis. Polylactose, a polymerization product of lactose and glucose, has been produced by reactive extrusion using a twin-screw extruder, with citric acid as the catalyst. Trials using powdered cheese whey permeate as the lactose source for this reaction were unsuccessful. The development of a laboratory method was necessary to investigate the effect of ingredients present in permeate powder that could be inhibiting polymerization. A Mars 6 Microwave Digestion System (CEM Corp., Matthews, NC) was used to heat and polymerize the sugars. The temperatures had to be lowered from extrusion conditions to produce a caramel-like product and not decompose the sugars. Small amounts of water had to be added to the reaction vessels to allow consistent heating of sugars between vessels. Elevated levels of water (22.86 and 28.57%, vol/wt) and calcium phosphate (0.928 and 1.856%, wt/wt) reduced the oligosaccharide yield in the laboratory method. Increasing the citric acid (catalyst) concentration increased the oligosaccharide yield for the pure sugar blend and when permeate powder was used. The utility of the laboratory method to predict oligosaccharide yields was confirmed during extrusion trials of permeate when this increased acid catalyst concentration resulted in similar oligosaccharide concentrations. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Advances for the Topographic Characterisation of SMC Materials

PubMed Central

Calvimontes, Alfredo; Grundke, Karina; Müller, Anett; Stamm, Manfred

2009-01-01

For a comprehensive study of Sheet Moulding Compound (SMC) surfaces, topographical data obtained by a contact-free optical method (chromatic aberration confocal imaging) were systematically acquired to characterise these surfaces with regard to their statistical, functional and volumetrical properties. Optimal sampling conditions (cut-off length and resolution) were obtained by a topographical-statistical procedure proposed in the present work. By using different length scales specific morphologies due to the influence of moulding conditions, metallic mould topography, glass fibre content and glass fibre orientation can be characterized. The aim of this study is to suggest a systematic topographical characterization procedure for composite materials in order to study and recognize the influence of production conditions on their surface quality.

Validation of a sensitive DNA walking strategy to characterise unauthorised GMOs using model food matrices mimicking common rice products.

PubMed

Fraiture, Marie-Alice; Herman, Philippe; Taverniers, Isabel; De Loose, Marc; Van Nieuwerburgh, Filip; Deforce, Dieter; Roosens, Nancy H

2015-04-15

To identify unauthorised GMOs in food and feed matrices, an integrated approach has recently been developed targeting pCAMBIA family vectors, highly present in transgenic plants. Their presence is first assessed by qPCR screening and is subsequently confirmed by characterising the transgene flanking regions, using DNA walking. Here, the DNA walking performance has been thoroughly tested for the first time, regarding the targeted DNA quality and quantity. Several assays, on model food matrices mimicking common rice products, have allowed to determine the limit of detection as well as the potential effects of food mixture and processing. This detection system allows the identification of transgenic insertions as low as 10 HGEs and was not affected by the presence of untargeted DNA. Moreover, despite the clear impact of food processing on DNA quality, this method was able to cope with degraded DNA. Given its specificity, sensitivity, reliability, applicability and practicability, the proposed approach is a key detection tool, easily implementable in enforcement laboratories. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Recent advances in characterisation of subsonic axisymmetric nozzles

NASA Astrophysics Data System (ADS)

Tesař, Václav

2018-06-01

Nozzles are devices generating jets. They are widely used in fluidics and also in active control of flows past bodies. Being practically always a component of larger system, design and optimisation of the system needs characterisation of nozzle properties by an invariant quantity. Perhaps surprisingly, no suitable invariant has been so far introduced. This article surveys approaches to characterisation quantities and presents several examples of their typical use in systems such as parallel operation of two nozzles, matching a nozzle to its fluid supply source, apparent resistance increase in flows with pulsation, and the secondary invariants of a family of quasi-similar nozzles.

THE QUANTIFICATION OF AQUEOUS TRACERS IN LABORATORY AQUIFER MODELS USING LIGHT TRANSMISSION VISUALIZATION METHOD

EPA Science Inventory

The quantification of solute concentrations in laboratory aquifer models has been largely limited to the use of sampling ports, from which samples are collected for external analysis. One of the drawbacks to this method is that the act of sampling may disturb plume dynamics and ...

Nanostructure characterisation of flow-formed Cr-Mo-V steel using transmission Kikuchi diffraction technique.

PubMed

Birosca, S; Ding, R; Ooi, S; Buckingham, R; Coleman, C; Dicks, K

2015-06-01

Nowadays flow-forming has become a desired near net shape manufacturing method as it provides excellent mechanical properties with improved surface finish and significant manufacturing cost reduction. However, the material is subjected to excessive plastic deformation during flow-forming process, generating a very fine and complex microstructure. In addition, the intense dislocation density and residual stress that is generated in the component during processing makes the microstructure characterisation using conventional micro-analytical tools challenging. Thus, the microstructure/property relationship study in such a material is rather difficult. In the present study a flow-formed Cr-Mo-V steel nanostructure and crystallographic texture were characterised by means of Transmission Kikuchi Diffraction (TKD). Here, TKD is shown to be a powerful technique in revealing very fine martensite laths within an austenite matrix. Moreover, fine precipitates in the order of 20-70 nm on the martensite lath boundaries were clearly imaged and characterised. This greatly assisted in understanding the preferable site formation of the carbides in such a complex microstructure. The results showed that the actual TKD spatial resolution was in the range of 5-10 nm using 25 kV for flow-formed Cr-Mo-V steel. Copyright © 2015 Elsevier B.V. All rights reserved.

Using Self-Explanations in the Laboratory to Connect Theory and Practice: The Decision/ Explanation/Observation/Inference Writing Method

ERIC Educational Resources Information Center

Van Duzor, Andrea Gay

2016-01-01

While many faculty seek to use student-centered, inquiry-based approaches in teaching laboratories, transitioning from traditional to inquiry instruction can be logistically challenging. This paper outlines use of a laboratory notebook and report writing-to-learn method that emphasizes student self-explanations of procedures and outcomes,…

Laboratory medicine in Ontario: its downsizing and the consequences on quality.

PubMed

Richardson, H

1999-12-01

Health care in Ontario consumes 35% of provincial government annual revenues. Fiscal constraint mandates restructuring of health services to maintain a fully, publicly-funded universally-accessible health system that is patient-focussed and health-outcome driven. Acute-care hospital restructuring under the authority of the Health Services Restructuring Commission and primary health-care reform characterise present government initiatives. Laboratory medicine services at about Can $1 billion annually account for about 5% of health expenditure. A Laboratory Services Restructuring Secretariat created by the Ministry of Health in 1995 has planned regionally-based integrated laboratory services systems bringing together public and private providers, designed a province-wide laboratory information system, developed a quality management program, reviewed the human resource needs for laboratory physicians, scientists and technologists, and recommended that the legislation be rewritten so as to be enabling - not controlling. Meanwhile both hospital and private laboratories have closed, leaving 296 in 1998 compared to 394 in 1991. Laboratory physician numbers at 39 per million population falls far short of the recommended target of 52 and many are within 10 years of retirement. Renewal of laboratory physicians and scientists to meet the shortfall is not occurring. The numbers of registered laboratory technologists has fallen by 6. 8% over 2 years. Consolidation and downsizing of laboratories with the formation of core laboratories has resulted in multi-discipline and cross discipline tasking of specialist technologists. Senior and middle level management technologists have been declared redundant. As a consequence, quality control practices have been hard hit. Plans to address these deficiencies through regional integration and sharing of resources remain to be implemented.

A new method of measuring gravitational acceleration in an undergraduate laboratory program

NASA Astrophysics Data System (ADS)

Wang, Qiaochu; Wang, Chang; Xiao, Yunhuan; Schulte, Jurgen; Shi, Qingfan

2018-01-01

This paper presents a high accuracy method to measure gravitational acceleration in an undergraduate laboratory program. The experiment is based on water in a cylindrical vessel rotating about its vertical axis at a constant speed. The water surface forms a paraboloid whose focal length is related to rotational period and gravitational acceleration. This experimental setup avoids classical source errors in determining the local value of gravitational acceleration, so prevalent in the common simple pendulum and inclined plane experiments. The presented method combines multiple physics concepts such as kinematics, classical mechanics and geometric optics, offering the opportunity for lateral as well as project-based learning.

Generation and characterisation of human umbilical cord derived mesenchymal stem cells by explant method.

PubMed

Yusoff, Z; Maqbool, M; George, E; Hassan, R; Ramasamy, R

2016-06-01

Mesenchymal stem cells (MSCs) derived from human umbilical cord (UC) have been considered as an important tool for treating various malignancies, tissue repair and organ regeneration. Umbilical cord-derived mesenchymal stem cells (UC-MSCs) are better alternative to MSCs that derived from bone marrow (BM-MSCs) as they are regarded as medical waste with little ethical concern for research and easily culture-expanded. In this present study, the foetal distal end of human UC was utilised to generate MSC by explant method. Upon in vitro culture, adherent cells with fibroblastic morphology were generated with rapid growth kinetics. Under the respective inductive conditions, these cells were capable of differentiating into adipocytes and osteocytes; express an array of standard MSC's surface markers CD29, CD73, CD90, CD106 and MHC-class I. Further assessment of immunosuppression activity revealed that MSCs generated from UC had profoundly inhibited the proliferation of mitogen-activated T lymphocytes in a dosedependent manner. The current laboratory findings have reinforced the application of explant method to generate UCMSCs thus, exploring an ideal platform to fulfil the increasing demand of MSCs for research and potential clinical use.

Do targeted written comments and the rubric method of delivery affect performance on future human physiology laboratory reports?

PubMed

Clayton, Zachary S; Wilds, Gabriel P; Mangum, Joshua E; Hocker, Austin D; Dawson, Sierra M

2016-09-01

We investigated how students performed on weekly two-page laboratory reports based on whether the grading rubric was provided to the student electronically or in paper form and the inclusion of one- to two-sentence targeted comments. Subjects were registered for a 289-student, third-year human physiology class with laboratory and were randomized into four groups related to rubric delivery and targeted comments. All students received feedback via the same detailed grading rubric. At the end of the term, subjects provided consent and a self-assessment of their rubric viewing rate and preferences. There were no differences in laboratory report scores between groups (P = 0.86), although scores did improve over time (P < 0.01). Students receiving targeted comments self-reported viewing their rubric more often than students that received no comments (P = 0.02), but the viewing rate was independent of the rubric delivery method (P = 0.15). Subjects with high rubric viewing rates did not have higher laboratory report grades than subjects with low viewing rates (P = 0.64). When asked about their preference for the future, 43% of respondents preferred the same method again (electronic or paper rubric) and 25% had no preference. We conclude that although student laboratory report grades improved over time, the rate and degree of improvement were not related to rubric delivery method or to the inclusion of targeted comments. Copyright © 2016 The American Physiological Society.

Accuracy of different bioinformatics methods in detecting antibiotic resistance and virulence factors from Staphylococcus aureus whole genome sequences.

PubMed

Mason, Amy; Foster, Dona; Bradley, Phelim; Golubchik, Tanya; Doumith, Michel; Gordon, N Claire; Pichon, Bruno; Iqbal, Zamin; Staves, Peter; Crook, Derrick; Walker, A Sarah; Kearns, Angela; Peto, Tim

2018-06-20

Background : In principle, whole genome sequencing (WGS) can predict phenotypic resistance directly from genotype, replacing laboratory-based tests. However, the contribution of different bioinformatics methods to genotype-phenotype discrepancies has not been systematically explored to date. Methods : We compared three WGS-based bioinformatics methods (Genefinder (read-based), Mykrobe (de Bruijn graph-based) and Typewriter (BLAST-based)) for predicting presence/absence of 83 different resistance determinants and virulence genes, and overall antimicrobial susceptibility, in 1379 Staphylococcus aureus isolates previously characterised by standard laboratory methods (disc diffusion, broth and/or agar dilution and PCR). Results : 99.5% (113830/114457) of individual resistance-determinant/virulence gene predictions were identical between all three methods, with only 627 (0.5%) discordant predictions, demonstrating high overall agreement (Fliess-Kappa=0.98, p<0.0001). Discrepancies when identified were in only one of the three methods for all genes except the cassette recombinase, ccrC(b ). Genotypic antimicrobial susceptibility prediction matched laboratory phenotype in 98.3% (14224/14464) cases (2720 (18.8%) resistant, 11504 (79.5%) susceptible). There was greater disagreement between the laboratory phenotypes and the combined genotypic predictions (97 (0.7%) phenotypically-susceptible but all bioinformatic methods reported resistance; 89 (0.6%) phenotypically-resistant, but all bioinformatics methods reported susceptible) than within the three bioinformatics methods (54 (0.4%) cases, 16 phenotypically-resistant, 38 phenotypically-susceptible). However, in 36/54 (67%), the consensus genotype matched the laboratory phenotype. Conclusions : In this study, the choice between these three specific bioinformatic methods to identify resistance-determinants or other genes in S. aureus did not prove critical, with all demonstrating high concordance with each other and

Physico-chemical characterisation, cytotoxic activity, and biocompatibility studies of tamoxifen-loaded solid lipid nanoparticles prepared via a temperature-modulated solidification method.

PubMed

Lakkadwala, Sushant; Nguyen, Sanko; Lawrence, Joseph; Nauli, Surya M; Nesamony, Jerry

2014-01-01

Solid lipid nanoparticles (SLNs) can efficiently and efficaciously incorporate anti-cancer agents. To prepare and characterise tamoxifen (TAM)-loaded SLNs. Glyceryl monostearate, Tween-80, and trehalose were used in SLNs. SLNs were tested via dynamic light scattering (DLS), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Characterisation studies revealed SLNs of about 540 nm with a negative surface charge and confirmed the entrapment of TAM in the SLNs. The entrapment efficiency was estimated to be 60%. The in vitro drug release profile demonstrated a gradual increase followed by a release plateau for several days. A drug concentration-dependent increase in cytotoxic activity was observed when the SLNs were evaluated in cell cultures. Biocompatible and stable lyophilised SLNs were successfully prepared and found to possess properties that may be utilised in an anti-cancer drug delivery system.

Characterisation of carbon nanotubes in the context of toxicity studies

USGS Publications Warehouse

Berhanu, D.; Dybowska, A.; Misra, S.K.; Stanley, C.J.; Ruenraroengsak, P.; Boccaccini, A.R.; Tetley, T.D.; Luoma, S.N.; Plant, J.A.; Valsami-Jones, E.

2009-01-01

Nanotechnology has the potential to revolutionise our futures, but has also prompted concerns about the possibility that nanomaterials may harm humans or the biosphere. The unique properties of nanoparticles, that give them novel size dependent functionalities, may also have the potential to cause harm. Discrepancies in existing human health and environmental studies have shown the importance of good quality, well-characterized reference nanomaterials for toxicological studies. Here we make a case for the importance of the detailed characterization of nanoparticles, using several methods, particularly to allow the recognition of impurities and the presence of chemically identical but structurally distinct phases. Methods to characterise fully, commercially available multi-wall carbon nanotubes at different scales, are presented. ?? 2009 Berhanu et al; licensee BioMed Central Ltd.

Numerical modeling of zero-offset laboratory data in a strong topographic environment: results for a spectral-element method and a discretized Kirchhoff integral method

NASA Astrophysics Data System (ADS)

Favretto-Cristini, Nathalie; Tantsereva, Anastasiya; Cristini, Paul; Ursin, Bjørn; Komatitsch, Dimitri; Aizenberg, Arkady M.

2014-08-01

Accurate simulation of seismic wave propagation in complex geological structures is of particular interest nowadays. However conventional methods may fail to simulate realistic wavefields in environments with great and rapid structural changes, due for instance to the presence of shadow zones, diffractions and/or edge effects. Different methods, developed to improve seismic modeling, are typically tested on synthetic configurations against analytical solutions for simple canonical problems or reference methods, or via direct comparison with real data acquired in situ. Such approaches have limitations, especially if the propagation occurs in a complex environment with strong-contrast reflectors and surface irregularities, as it can be difficult to determine the method which gives the best approximation of the "real" solution, or to interpret the results obtained without an a priori knowledge of the geologic environment. An alternative approach for seismics consists in comparing the synthetic data with high-quality data collected in laboratory experiments under controlled conditions for a known configuration. In contrast with numerical experiments, laboratory data possess many of the characteristics of field data, as real waves propagate through models with no numerical approximations. We thus present a comparison of laboratory-scaled measurements of 3D zero-offset wave reflection of broadband pulses from a strong topographic environment immersed in a water tank with numerical data simulated by means of a spectral-element method and a discretized Kirchhoff integral method. The results indicate a good quantitative fit in terms of time arrivals and acceptable fit in amplitudes for all datasets.

A STUDY OF THE APPLICATION OF LABORATORY TRAINING METHODS TO PROGRAMS AT AIR UNIVERSITY (OCTOBER 1964-JULY 1965).

ERIC Educational Resources Information Center

BOYER, RONALD K.; AND OTHERS

THIS 1964-65 STUDY SOUGHT TO EXPLORE APPLICATIONS OF LABORATORY TRAINING TO AIR UNIVERSITY PROGRAMS, TO PREDICT PROBLEMS IN ADAPTING THE LABORATORY METHOD TO SUCH PROGRAMS, AND TO DETERMINE USEFUL MODIFICATIONS THAT MIGHT BE MADE IN TRAINING DESIGNS. A GROUP OF 25 AIR UNIVERSITY PERSONNEL REPRESENTING VARIOUS RANKS AND SCHOOLS ATTENDED AN…

Field investigation with real-time virus genetic characterisation support of a cluster of Ebola virus disease cases in Dubréka, Guinea, April to June 2015.

PubMed

Pini, Alessandro; Zomahoun, Delayo; Duraffour, Sophie; Derrough, Tarik; Charles, Myrna; Quick, Joshua; Loman, Nick; Cowley, Lauren; Leno, Mamadou; Ouedraogo, Nobila; Thiam, Oumou; Hernández-Romieu, Alfonso; Iko, Annie; Keita, Halimatou; Konate, Djiba; Soumah, Aboubacar Aboubak; Bouchouar, Etran; Ileka-Priouzeau, Samuel; Keita, Sakoba; Diallo, Boubacar; Cisse, Fode; Jansa, Josep; Carroll, Miles; Günther, Stephan; Severi, Ettore; Formenty, Pierre

2018-03-01

On 11 May 2015, the Dubréka prefecture, Guinea, reported nine laboratory-confirmed cases of Ebola virus disease (EVD). None could be epidemiologically linked to cases previously reported in the prefecture. We describe the epidemiological and molecular investigations of this event. We used the Dubréka EVD registers and the Ebola treatment centre's (ETC) records to characterise chains of transmission. Real-time field Ebola virus sequencing was employed to support epidemiological results. An epidemiological cluster of 32 cases was found, of which 27 were laboratory confirmed, 24 were isolated and 20 died. Real-time viral sequencing on 12 cases demonstrated SL3 lineage viruses with sequences differing by one to three nt inside a single phylogenetic cluster. For isolated cases, the average time between symptom onset and ETC referral was 2.8 days (interquartile range (IQR): 1-4). The average time between sample collection and molecular results' availability was 3 days (IQR: 2-5). In an area with scarce resources, the genetic characterisation supported the outbreak investigations in real time, linking cases where epidemiological investigation was limited and reassuring that the responsible strain was already circulating in Guinea. We recommend coupling thorough epidemiological and genomic investigations to control EVD clusters.

Performance of human fecal anaerobe-associated PCR-based assays in a multi-laboratory method evaluation study

USGS Publications Warehouse

Layton, Blythe A.; Cao, Yiping; Ebentier, Darcy L.; Hanley, Kaitlyn; Ballesté, Elisenda; Brandão, João; Byappanahalli, Muruleedhara N.; Converse, Reagan; Farnleitner, Andreas H.; Gentry-Shields, Jennifer; Gourmelon, Michèle; Lee, Chang Soo; Lee, Jiyoung; Lozach, Solen; Madi, Tania; Meijer, Wim G.; Noble, Rachel; Peed, Lindsay; Reischer, Georg H.; Rodrigues, Raquel; Rose, Joan B.; Schriewer, Alexander; Sinigalliano, Chris; Srinivasan, Sangeetha; Stewart, Jill; ,; Laurie, C.; Wang, Dan; Whitman, Richard; Wuertz, Stefan; Jay, Jenny; Holden, Patricia A.; Boehm, Alexandria B.; Shanks, Orin; Griffith, John F.

2013-01-01

A number of PCR-based methods for detecting human fecal material in environmental waters have been developed over the past decade, but these methods have rarely received independent comparative testing in large multi-laboratory studies. Here, we evaluated ten of these methods (BacH, BacHum-UCD, Bacteroides thetaiotaomicron (BtH), BsteriF1, gyrB, HF183 endpoint, HF183 SYBR, HF183 Taqman®, HumM2, and Methanobrevibacter smithii nifH (Mnif)) using 64 blind samples prepared in one laboratory. The blind samples contained either one or two fecal sources from human, wastewater or non-human sources. The assay results were assessed for presence/absence of the human markers and also quantitatively while varying the following: 1) classification of samples that were detected but not quantifiable (DNQ) as positive or negative; 2) reference fecal sample concentration unit of measure (such as culturable indicator bacteria, wet mass, total DNA, etc); and 3) human fecal source type (stool, sewage or septage). Assay performance using presence/absence metrics was found to depend on the classification of DNQ samples. The assays that performed best quantitatively varied based on the fecal concentration unit of measure and laboratory protocol. All methods were consistently more sensitive to human stools compared to sewage or septage in both the presence/absence and quantitative analysis. Overall, HF183 Taqman® was found to be the most effective marker of human fecal contamination in this California-based study.

Inter-laboratory comparisons of hexenuronic acid measurements in kraft eucalyptus pulps using a UV-Vis spectroscopic method

Treesearch

J.Y. Zhu; H.F Zhou; Chai X.S.; Donna Johannes; Richard Pope; Cristina Valls; M. Blanca Roncero

2014-01-01

An inter-laboratory comparison of a UV-Vis spectroscopic method (TAPPI T 282 om-13 “Hexeneuronic acid content of chemical pulp”) for hexeneuronic acid measurements was conducted using three eucalyptus kraft pulps. The pulp samples were produced in a laboratory at kappa numbers of approximately 14, 20, and 35. The hexeneuronic acid contents of the three pulps were...

Comprehensive characterisation of sewage sludge for thermochemical conversion processes - Based on Singapore survey.

PubMed

Chan, Wei Ping; Wang, Jing-Yuan

2016-08-01

Recently, sludge attracted great interest as a potential feedstock in thermochemical conversion processes. However, compositions and thermal degradation behaviours of sludge were highly complex and distinctive compared to other traditional feedstock led to a need of fundamental research on sludge. Comprehensive characterisation of sludge specifically for thermochemical conversion was carried out for all existing Water Reclamation Plants in Singapore. In total, 14 sludge samples collected based on the type, plant, and batch categorisation. Existing characterisation methods for physical and chemical properties were analysed and reviewed using the collected samples. Qualitative similarities and quantitative variations of different sludge samples were identified and discussed. Oxidation of inorganic in sludge during ash forming analysis found to be causing significant deviations on proximate and ultimate analysis. Therefore, alternative parameters and comparison basis including Fixed Residues (FR), Inorganic Matters (IM) and Total Inorganics (TI) were proposed for better understanding on the thermochemical characteristics of sludge. Copyright © 2016 Elsevier Ltd. All rights reserved.

Incidence and serotype characterisation of Streptococcus agalactiae in a Portuguese hospital.

PubMed

Pinto, Ana Mafalda; Pereira, Tamegão Aires; Alves, Valquíria; Araújo, António; Lage, Olga Maria

2018-06-01

Streptococcus agalactiae, commonly known as group B Streptococcus (GBS), has been recognised as a worldwide causative pathogenic agent of neonatal sepsis, meningitis and pneumonia. To better understand the behaviour of S. agalactiae in pregnant women from a hospital from the North of Portugal, retrospective analyses were performed to describe epidemiological, clinical and microbiological characteristics of the isolates obtained. Based on laboratorial records and the hospital's patient files, a 6-year retrospective study was performed to analyse S. agalactiae isolates from screened pregnant women between 35 and 37 weeks of gestation and hospitalised neonates from pregnant women between 24 and 41 weeks of gestation admitted in Hospital Pedro Hispano. Serotype characterisation was also performed in 67 GBS strains. In 6692 pregnant women between 35 and 37 weeks of gestation screened between 2011 and 2016, a total of 1377 S. agalactiae isolates (21%) were found. A high percentage (40%) of unknown colonisation status among hospitalised neonates from pregnant women between 24 and 41 weeks of gestations was also found. The incidence of neonatal sepsis was 8.7 (95% CI 7.0 to 10.8) cases per 1000 live births. Regarding serotype characterisation, serotype III (22.4%) was the most frequent, followed by serotype Ia (19.4%) and serotypes Ib and V (both with 17.9%). High epidemiological values of GBS colonisation and incidence were found in this study. In Portugal studies on the epidemiology and behaviour of S. agalactiae remain limited, reinforcing the importance and need for S. agalactiae screening across the country. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Determination of Calcium in Dietary Supplements: Statistical Comparison of Methods in the Analytical Laboratory

ERIC Educational Resources Information Center

Garvey, Sarah L.; Shahmohammadi, Golbon; McLain, Derek R.; Dietz, Mark L.

2015-01-01

A laboratory experiment is described in which students compare two methods for the determination of the calcium content of commercial dietary supplement tablets. In a two-week sequence, the sample tablets are first analyzed via complexometric titration with ethylenediaminetetraacetic acid and then, following ion exchange of the calcium ion present…

Collaborative Testing in Practical Laboratories: An Effective Teaching-Learning Method in Histology.

PubMed

Guo, Yuping; Li, Enzhong

2016-01-01

This article presents an experimental teaching and learning program used in histology with first-year students in the second term in the Faculty of Biology at Huanghuai University, China. Eighty-six students were divided randomly into two groups (n=43 per group). Tests were conducted at the end of each practical laboratory (10 laboratories in total) in which collaborative testing was used in the experimental group and traditional testing in the control group. To assess achievement, a final examination in histology was carried out at the end of the course. To determine students' attitude to the teaching styles, a questionnaire survey was conducted at the end of the term. Results showed that students preferred the collaborative testing format. In the experimental group, students' scores were significantly higher than those of students in the control group in final examinations. These findings indicate that collaborative testing enhances student learning and understanding of the material taught, and suggest that collaborative testing is an effective teaching-learning method in histology.

Effect of image scaling and segmentation in digital rock characterisation

NASA Astrophysics Data System (ADS)

Jones, B. D.; Feng, Y. T.

2016-04-01

Digital material characterisation from microstructural geometry is an emerging field in computer simulation. For permeability characterisation, a variety of studies exist where the lattice Boltzmann method (LBM) has been used in conjunction with computed tomography (CT) imaging to simulate fluid flow through microscopic rock pores. While these previous works show that the technique is applicable, the use of binary image segmentation and the bounceback boundary condition results in a loss of grain surface definition when the modelled geometry is compared to the original CT image. We apply the immersed moving boundary (IMB) condition of Noble and Torczynski as a partial bounceback boundary condition which may be used to better represent the geometric definition provided by a CT image. The IMB condition is validated against published work on idealised porous geometries in both 2D and 3D. Following this, greyscale image segmentation is applied to a CT image of Diemelstadt sandstone. By varying the mapping of CT voxel densities to lattice sites, it is shown that binary image segmentation may underestimate the true permeability of the sample. A CUDA-C-based code, LBM-C, was developed specifically for this work and leverages GPU hardware in order to carry out computations.

Characterising soil surface roughness with a frequency modulated polarimetric radar

NASA Astrophysics Data System (ADS)

Seeger, Manuel; Gronz, Oliver; Beiske, Joshua; Klein, Tobias

2014-05-01

Soil surface roughness is considered crucial for soil erosion as it determines the effective surface exposed to the raindrop impact. It regulates surface runoff velocity and it causes runoff concentration. But a comprehensive characterisation of the shape of the soils' surface is still difficult to achieve. Photographic systems and terrestrial laser-scanning are nowadays able to generate high resolution DEMs, but the derivation of roughness parameters is still not clear. Spaceborne radar systems are used for about 3 decades for earth survey. Spatial soil moisture distribution, ice sheet monitoring and earth-wide topographic survey are the main objectives of these radar systems, working generally with frequencies <10 GHz. Contrasting with this, technologies emitting frequencies up to 77 GHz are generally used for object tracking purposes. But it is known, that the reflection characteristics, such as intensity and polarisation, strongly depend on the properties of the target object. A new design of a frequency modulated continuous wave radar, emitting a right hand shaped circular polarization and receiving both polarization directions, right and left-hand shaped, is tested here for its ability to detect and quantify different surface roughness. The reflection characteristics of 4 different materials 1) steel, 2) sand (0,5-1 mm), 3) fine (2-4 mm) and 4) coarse (15-30 mm) rock-fragments and different roughness as well as moisture content are analysed. In addition, the signals are taken at 2 different angles to the soil's surface (90° and 70°). For quantification of the roughness, a photographic method (Structure-from-Motion) is applied to generate a detailed DEM and random roughness (RR) is calculated. To characterise the radar signal, different ratios of the reflected channels and polarisations are calculated. The signals show differences for all substrates, also clearly visible between sand and fine rock fragments, despite a wavelength of 1 cm of the

Organic Phosphorus Characterisation in Agricultural Soils by Enzyme Addition Assays

NASA Astrophysics Data System (ADS)

Jarosch, Klaus; Frossard, Emmanuel; Bünemann, Else K.

2013-04-01

by various soil specific variables. Thus, the characterisation of soil organic P by enzyme addition assays was further developed and shown to be applicable on a very wide range of soil types. The method also bears the potential for describing translocation processes of dissolved organic P species in soil - aquifer systems. Key words: soil organic phosphorus characterisation, enzyme additions, dissolved organic P

Thermal comfort of aeroplane seats: influence of different seat materials and the use of laboratory test methods.

PubMed

Bartels, Volkmar T

2003-07-01

This study determined the influence of different cover and cushion materials on the thermal comfort of aeroplane seats. Different materials as well as ready made seats were investigated by the physiological laboratory test methods Skin Model and seat comfort tester. Additionally, seat trials with human test subjects were performed in a climatic chamber. Results show that a fabric cover produces a considerably higher sweat transport than leather. A three-dimensional knitted spacer fabric turns out to be the better cushion alternative in comparison to a moulded foam pad. Results from the physiological laboratory test methods nicely correspond to the seat trials with human test subjects.

ICRH antenna S-matrix measurements and plasma coupling characterisation at JET

NASA Astrophysics Data System (ADS)

Monakhov, I.; Jacquet, P.; Blackman, T.; Bobkov, V.; Dumortier, P.; Helou, W.; Lerche, E.; Kirov, K.; Milanesio, D.; Maggiora, R.; Noble, C.; Contributors, JET

2018-04-01

The paper is dedicated to the characterisation of multi-strap ICRH antenna coupling to plasma. Relevance of traditional concept of coupling resistance to antennas with mutually coupled straps is revised and the importance of antenna port excitation consistency for application of the concept is highlighted. A method of antenna S-matrix measurement in presence of plasma is discussed allowing deeper insight into the problem of antenna-plasma coupling. The method is based entirely on the RF plant hardware and control facilities available at JET and it involves application of variable phasing between the antenna straps during the RF plant operations at  >100 kW. Unlike traditional techniques relying on low-power (~10 mW) network analysers, the applied antenna voltage amplitudes are relevant to practical conditions of ICRH operations; crucially, they are high enough to minimise possible effects of antenna loading non-linearity due to the RF sheath effects and other phenomena which could affect low-power measurements. The method has been successfully applied at JET to conventional 4-port ICRH antennas energised at frequencies of 33 MHz, 42 MHz and 51 MHz during L-mode plasma discharges while different gas injection modules (GIMs) were used to maintain comparable plasma densities during the pulses. The S-matrix assessment and its subsequent processing yielding ‘global’ antenna coupling resistances in conditions of equalised port maximum voltages allowed consistent description of antenna coupling to plasma at different strap phasing, operational frequencies and applied GIMs. Comprehensive experimental characterisation of mutually coupled antenna straps in presence of plasma also provided a unique opportunity for in-depth verification of TOPICA computer simulations.

Spectroscopy applied to feed additives of the European Union Reference Laboratory: a valuable tool for traceability.

PubMed

Omar, Jone; Slowikowski, Boleslaw; Boix, Ana; von Holst, Christoph

2017-08-01

Feed additives need to be authorised to be placed on the market according to Regulation (EU) No. 1831/2003. Next to laying down the procedural requirements, the regulation creates the European Union Reference Laboratory for Feed Additives (EURL-FA) and requires that applicants send samples to the EURL-FA. Once authorised, the characteristics of the marketed feed additives should correspond to those deposited in the sample bank of the EURL-FA. For this purpose, the submitted samples were subjected to near-infrared (NIR) and Raman spectroscopy for spectral characterisation. These techniques have the valuable potential of characterising the feed additives in a non-destructive manner without any complicated sample preparation. This paper describes the capability of spectroscopy for a rapid characterisation of products to establish whether specific authorisation criteria are met. This study is based on the analysis of feed additive samples from different categories and functional groups, namely products containing (1) selenium, (2) zinc and manganese, (3) vitamins and (4) essential oils such as oregano and thyme oil. The use of chemometrics turned out to be crucial, especially in cases where the differentiation of spectra by visual inspection was very difficult.

Next generation microbiological risk assessment-Potential of omics data for hazard characterisation.

PubMed

Haddad, Nabila; Johnson, Nick; Kathariou, Sophia; Métris, Aline; Phister, Trevor; Pielaat, Annemarie; Tassou, Chrysoula; Wells-Bennik, Marjon H J; Zwietering, Marcel H

2018-04-12

According to the World Health Organization estimates in 2015, 600 million people fall ill every year from contaminated food and 420,000 die. Microbial risk assessment (MRA) was developed as a tool to reduce and prevent risks presented by pathogens and/or their toxins. MRA is organized in four steps to analyse information and assist in both designing appropriate control options and implementation of regulatory decisions and programs. Among the four steps, hazard characterisation is performed to establish the probability and severity of a disease outcome, which is determined as function of the dose of toxin and/or pathogen ingested. This dose-response relationship is subject to both variability and uncertainty. The purpose of this review/opinion article is to discuss how Next Generation Omics can impact hazard characterisation and, more precisely, how it can improve our understanding of variability and limit the uncertainty in the dose-response relation. The expansion of omics tools (e.g. genomics, transcriptomics, proteomics and metabolomics) allows for a better understanding of pathogenicity mechanisms and virulence levels of bacterial strains. Detection and identification of virulence genes, comparative genomics, analyses of mRNA and protein levels and the development of biomarkers can help in building a mechanistic dose-response model to predict disease severity. In this respect, systems biology can help to identify critical system characteristics that confer virulence and explain variability between strains. Despite challenges in the integration of omics into risk assessment, some omics methods have already been used by regulatory agencies for hazard identification. Standardized methods, reproducibility and datasets obtained from realistic conditions remain a challenge, and are needed to improve accuracy of hazard characterisation. When these improvements are realized, they will allow the health authorities and government policy makers to prioritize hazards more

Characterisation of large area THGEMs and experimental measurement of the Townsend coefficients for CF4

NASA Astrophysics Data System (ADS)

Burns, J.; Crane, T.; Ezeribe, A. C.; Grove, C. L.; Lynch, W.; Scarff, A.; Spooner, N. J. C.; Steer, C.

2017-10-01

Whilst the performance of small THGEMs is well known, here we consider the challenges in scaling these up to large area charge readouts. We first verify the expected gain of larger THGEMs by reporting experimental Townsend coefficients for a 10 cm diameter THGEM in low-pressure CF4. Large area 50 cm by 50 cm THGEMs were sourced from a commercial PCB supplier and geometrical imperfections were observed which we quantified using an optical camera setup. The large area THGEMs were experimentally characterised at Boulby Underground Laboratory through a series of gain calibrations and alpha spectrum measurements. ANSYS, Magboltz and Garfield++ simulations of the design of a TPC based on the large area THGEMs are presented. We also consider their implications for directional dark matter research and potential applications within nuclear security.

Non-destructive mapping of grain orientations in 3D by laboratory X-ray microscopy

NASA Astrophysics Data System (ADS)

McDonald, S. A.; Reischig, P.; Holzner, C.; Lauridsen, E. M.; Withers, P. J.; Merkle, A. P.; Feser, M.

2015-10-01

The ability to characterise crystallographic microstructure, non-destructively and in three-dimensions, is a powerful tool for understanding many aspects related to damage and deformation mechanisms in polycrystalline materials. To this end, the technique of X-ray diffraction contrast tomography (DCT) using monochromatic synchrotron and polychromatic laboratory X-ray sources has been shown to be capable of mapping crystal grains and their orientations non-destructively in 3D. Here we describe a novel laboratory-based X-ray DCT modality (LabDCT), enabling the wider accessibility of the DCT technique for routine use and in-depth studies of, for example, temporal changes in crystallographic grain structure non-destructively over time through ‘4D’ in situ time-lapse studies. The capability of the technique is demonstrated by studying a titanium alloy (Ti-β21S) sample. In the current implementation the smallest grains that can be reliably detected are around 40 μm. The individual grain locations and orientations are reconstructed using the LabDCT method and the results are validated against independent measurements from phase contrast tomography and electron backscatter diffraction respectively. Application of the technique promises to provide important insights related to the roles of recrystallization and grain growth on materials properties as well as supporting 3D polycrystalline modelling of materials performance.

Non-destructive mapping of grain orientations in 3D by laboratory X-ray microscopy.

PubMed

McDonald, S A; Reischig, P; Holzner, C; Lauridsen, E M; Withers, P J; Merkle, A P; Feser, M

2015-10-23

The ability to characterise crystallographic microstructure, non-destructively and in three-dimensions, is a powerful tool for understanding many aspects related to damage and deformation mechanisms in polycrystalline materials. To this end, the technique of X-ray diffraction contrast tomography (DCT) using monochromatic synchrotron and polychromatic laboratory X-ray sources has been shown to be capable of mapping crystal grains and their orientations non-destructively in 3D. Here we describe a novel laboratory-based X-ray DCT modality (LabDCT), enabling the wider accessibility of the DCT technique for routine use and in-depth studies of, for example, temporal changes in crystallographic grain structure non-destructively over time through '4D' in situ time-lapse studies. The capability of the technique is demonstrated by studying a titanium alloy (Ti-β21S) sample. In the current implementation the smallest grains that can be reliably detected are around 40 μm. The individual grain locations and orientations are reconstructed using the LabDCT method and the results are validated against independent measurements from phase contrast tomography and electron backscatter diffraction respectively. Application of the technique promises to provide important insights related to the roles of recrystallization and grain growth on materials properties as well as supporting 3D polycrystalline modelling of materials performance.

An improved method for field extraction and laboratory analysis of large, intact soil cores

USGS Publications Warehouse

Tindall, J.A.; Hemmen, K.; Dowd, J.F.

1992-01-01

Various methods have been proposed for the extraction of large, undisturbed soil cores and for subsequent analysis of fluid movement within the cores. The major problems associated with these methods are expense, cumbersome field extraction, and inadequate simulation of unsaturated flow conditions. A field and laboratory procedure is presented that is economical, convenient, and simulates unsaturated and saturated flow without interface flow problems and can be used on a variety of soil types. In the field, a stainless steel core barrel is hydraulically pressed into the soil (30-cm diam. and 38 cm high), the barrel and core are extracted from the soil, and after the barrel is removed from the core, the core is then wrapped securely with flexible sheet metal and a stainless mesh screen is attached to the bottom of the core for support. In the laboratory the soil core is set atop a porous ceramic plate over which a soil-diatomaceous earth slurry has been poured to assure good contact between plate and core. A cardboard cylinder (mold) is fastened around the core and the empty space filled with paraffin wax. Soil cores were tested under saturated and unsaturated conditions using a hanging water column for potentials ???0. Breakthrough curves indicated that no interface flow occurred along the edge of the core. This procedure proved to be reliable for field extraction of large, intact soil cores and for laboratory analysis of solute transport.

Visual texture for automated characterisation of geological features in borehole televiewer imagery

NASA Astrophysics Data System (ADS)

Al-Sit, Waleed; Al-Nuaimy, Waleed; Marelli, Matteo; Al-Ataby, Ali

2015-08-01

Detailed characterisation of the structure of subsurface fractures is greatly facilitated by digital borehole logging instruments, the interpretation of which is typically time-consuming and labour-intensive. Despite recent advances towards autonomy and automation, the final interpretation remains heavily dependent on the skill, experience, alertness and consistency of a human operator. Existing computational tools fail to detect layers between rocks that do not exhibit distinct fracture boundaries, and often struggle characterising cross-cutting layers and partial fractures. This paper presents a novel approach to the characterisation of planar rock discontinuities from digital images of borehole logs. Multi-resolution texture segmentation and pattern recognition techniques utilising Gabor filters are combined with an iterative adaptation of the Hough transform to enable non-distinct, partial, distorted and steep fractures and layers to be accurately identified and characterised in a fully automated fashion. This approach has successfully detected fractures and layers with high detection accuracy and at a relatively low computational cost.

Characterisation of aerosol combustible mixtures generated using condensation process

NASA Astrophysics Data System (ADS)

Saat, Aminuddin; Dutta, Nilabza; Wahid, Mazlan A.

2012-06-01

An accidental release of a liquid flammable substance might be formed as an aerosol (droplet and vapour mixture). This phenomenon might be due to high pressure sprays, pressurised liquid leaks and through condensation when hot vapour is rapidly cooled. Such phenomena require a fundamental investigation of mixture characterisation prior to any subsequent process such as evaporation and combustion. This paper describes characterisation study of droplet and vapour mixtures generated in a fan stirred vessel using condensation technique. Aerosol of isooctane mixtures were generated by expansion from initially a premixed gaseous fuel-air mixture. The distribution of droplets within the mixture was characterised using laser diagnostics. Nearly monosized droplet clouds were generated and the droplet diameter was defined as a function of expansion time. The effect of changes in pressure, temperature, fuel-air fraction and expansion ratio on droplet diameter was evaluated. It is shown that aerosol generation by expansion was influenced by the initial pressure and temperature, equivalence ratio and expansion rates. All these parameters affected the onset of condensation which in turn affected the variation in droplet diameter.

Mechanical, thermal and morphological characterisation of 3D porous Pennisetum purpureum/PLA biocomposites scaffold.

PubMed

Revati, R; Abdul Majid, M S; Ridzuan, M J M; Normahira, M; Mohd Nasir, N F; Rahman Y, M N; Gibson, A G

2017-06-01

The mechanical, thermal, and morphological properties of a 3D porous Pennisetum purpureum (PP)/polylactic acid (PLA) based scaffold were investigated. In this study, a scaffold containing P. purpureum and PLA was produced using the solvent casting and particulate leaching method. P. purpureum fibre, also locally known as Napier grass, is composed of 46% cellulose, 34% hemicellulose, and 20% lignin. PLA composites with various P. purpureum contents (10%, 20%, and 30%) were prepared and subsequently characterised. The morphologies, structures and thermal behaviours of the prepared composite scaffolds were characterised using field-emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The morphology was studied using FESEM; the scaffold possessed 70-200μm-sized pores with a high level of interconnectivity. The moisture content and mechanical properties of the developed porous scaffolds were further characterised. The P. purpureum/PLA scaffold had a greater porosity factor (99%) and compression modulus (5.25MPa) than those of the pure PLA scaffold (1.73MPa). From the results, it can be concluded that the properties of the highly porous P. purpureum/PLA scaffold developed in this study can be controlled and optimised. This can be used to facilitate the construction of implantable tissue-engineered cartilage. Copyright © 2017 Elsevier B.V. All rights reserved.

Micro-Physical characterisation of Convective & Stratiform Rainfall at Tropics

NASA Astrophysics Data System (ADS)

Sreekanth, T. S.

Large Micro-Physical characterisation of Convective & Stratiform Rainfall at Tropics begin{center} begin{center} Sreekanth T S*, Suby Symon*, G. Mohan Kumar (1) , and V Sasi Kumar (2) *Centre for Earth Science Studies, Akkulam, Thiruvananthapuram (1) D-330, Swathi Nagar, West Fort, Thiruvananthapuram 695023 (2) 32. NCC Nagar, Peroorkada, Thiruvananthapuram ABSTRACT Micro-physical parameters of rainfall such as rain drop size & fall speed distribution, mass weighted mean diameter, Total no. of rain drops, Normalisation parameters for rain intensity, maximum & minimum drop diameter from different rain intensity ranges, from both stratiform and convective rain events were analysed. Convective -Stratiform classification was done by the method followed by Testud et al (2001) and as an additional information electrical behaviour of clouds from Atmospheric Electric Field Mill was also used. Events which cannot be included in both types are termed as 'mixed precipitation' and identified separately. For the three years 2011, 2012 & 2013, rain events from both convective & stratiform origin are identified from three seasons viz Pre-Monsoon (March-May), Monsoon (June-September) and Post-Monsoon (October-December). Micro-physical characterisation was done for each rain events and analysed. Ground based and radar observations were made and classification of stratiform and convective rainfall was done by the method followed by Testud et al (2001). Radar bright band and non bright band analysis was done for confimation of stratifom and convective rain respectievely. Atmospheric electric field data from electric field mill is also used for confirmation of convection during convective events. Statistical analyses revealed that the standard deviation of rain drop size in higher rain rates are higher than in lower rain rates. Normalised drop size distribution is ploted for selected events from both forms. Inter relations between various precipitation parameters were analysed in three

A Static Method as an Alternative to Gel Chromatography: An Experiment for the Undergraduate Biochemistry Laboratory

ERIC Educational Resources Information Center

Burum, Alex D.; Splittgerber, Allan G.

2008-01-01

This article describes a static method as an alternative to gel chromatography, which may be used as an undergraduate laboratory experiment. In this method, a constant mass of Sephadex gel is swollen in a series of protein solutions. UV-vis spectrophotometry is used to find a partition coefficient, KD, that indicates the fraction of the interior…

Laboratory analytical methods for the determination of the hydrocarbon status of soils (a review)

NASA Astrophysics Data System (ADS)

Pikovskii, Yu. I.; Korotkov, L. A.; Smirnova, M. A.; Kovach, R. G.

2017-10-01

Laboratory analytical methods suitable for the determination of the hydrocarbon status of soils (a specific soil characteristic involving information on the total content and qualitative features of soluble (bitumoid) carbonaceous substances and individual hydrocarbons (polycyclic aromatic hydrocarbons, alkanes, etc.) in bitumoid, as well as the composition and content of hydrocarbon gases) have been considered. Among different physicochemical methods of study, attention is focused on the methods suitable for the wide use. Luminescence-bituminological analysis, low-temperature spectrofluorimetry (Shpolskii spectroscopy), infrared (IR) spectroscopy, gas chromatography, chromatography-mass spectrometry, and some other methods have been characterized, as well as sample preparation features. Advantages and limitations of each of these methods are described; their efficiency, instrumental complexity, analysis duration, and accuracy are assessed.

Field and laboratory arsenic speciation methods and their application to natural-water analysis

USGS Publications Warehouse

Bednar, A.J.; Garbarino, J.R.; Burkhardt, M.R.; Ranville, J.F.; Wildeman, T.R.

2004-01-01

The toxic and carcinogenic properties of inorganic and organic arsenic species make their determination in natural water vitally important. Determination of individual inorganic and organic arsenic species is critical because the toxicology, mobility, and adsorptivity vary substantially. Several methods for the speciation of arsenic in groundwater, surface-water, and acid mine drainage sample matrices using field and laboratory techniques are presented. The methods provide quantitative determination of arsenite [As(III)], arsenate [As(V)], monomethylarsonate (MMA), dimethylarsinate (DMA), and roxarsone in 2-8min at detection limits of less than 1??g arsenic per liter (??g AsL-1). All the methods use anion exchange chromatography to separate the arsenic species and inductively coupled plasma-mass spectrometry as an arsenic-specific detector. Different methods were needed because some sample matrices did not have all arsenic species present or were incompatible with particular high-performance liquid chromatography (HPLC) mobile phases. The bias and variability of the methods were evaluated using total arsenic, As(III), As(V), DMA, and MMA results from more than 100 surface-water, groundwater, and acid mine drainage samples, and reference materials. Concentrations in test samples were as much as 13,000??g AsL-1 for As(III) and 3700??g AsL-1 for As(V). Methylated arsenic species were less than 100??g AsL-1 and were found only in certain surface-water samples, and roxarsone was not detected in any of the water samples tested. The distribution of inorganic arsenic species in the test samples ranged from 0% to 90% As(III). Laboratory-speciation method variability for As(III), As(V), MMA, and DMA in reagent water at 0.5??g AsL-1 was 8-13% (n=7). Field-speciation method variability for As(III) and As(V) at 1??g AsL-1 in reagent water was 3-4% (n=3). ?? 2003 Elsevier Ltd. All rights reserved.

Characterisation of cold plasma treated beef and dairy lipids using spectroscopic and chromatographic methods.

PubMed

Sarangapani, Chaitanya; Ryan Keogh, David; Dunne, Julie; Bourke, Paula; Cullen, P J

2017-11-15

The efficacy of cold plasma for inactivation of food-borne pathogens in foods is established. However, insights on cold plasma-food interactions in terms of quality effects, particularly for oils and fats, are sparse. This study evaluated plasma-induced lipid oxidation of model matrices, namely dairy and meat fats. Product characterisation was performed using FTIR, 1 H NMR and chromatographic techniques. The oxidation of lipids by cold plasma followed the Criegee mechanism and typical oxidation products identified included ozonides, aldehydes (hexanal, pentenal, nonanal and nonenal) and carboxylic acids (9-oxononanoic acid, octanoic acid, nonanoic acid), along with hydroperoxides (9- and 13-hydroperoxy-octadecadienoylglycerol species). However, these oxidation products were only identified following extended treatment times of 30min and were also a function of applied voltage level. Understanding cold plasma interactions with food lipids and the critical parameters governing lipid oxidation is required prior to the industrial adoption of this technology for food products with high fat contents. Copyright © 2017 Elsevier Ltd. All rights reserved.

Studying relationships between environment and malaria incidence in Camopi (French Guiana) through the objective selection of buffer-based landscape characterisations

PubMed Central

2011-01-01

Background Malaria remains a major health problem in French Guiana, with a mean of 3800 cases each year. A previous study in Camopi, an Amerindian village on the Oyapock River, highlighted the major contribution of environmental features to the incidence of malaria attacks. We propose a method for the objective selection of the best multivariate peridomestic landscape characterisation that maximises the chances of identifying relationships between environmental features and malaria incidence, statistically significant and meaningful from an epidemiological point of view. Methods A land-cover map, the hydrological network and the geolocalised inhabited houses were used to characterise the peridomestic landscape in eleven discoid buffers with radii of 50, 100, 200, 300, 400, 500, 600, 700, 800, 900 and 1000 metres. Buffer-based landscape characterisations were first compared in terms of their capacity to discriminate between sites within the geographic space and of their effective multidimensionality in variable space. The Akaike information criterion (AIC) was then used to select the landscape model best explaining the incidences of P. vivax and P. falciparum malaria. Finally, we calculated Pearson correlation coefficients for the relationships between environmental variables and malaria incidence, by species, for the more relevant buffers. Results The optimal buffers for environmental characterisation had radii of 100 m around houses for P. vivax and 400 m around houses for P. falciparum. The incidence of P. falciparum malaria seemed to be more strongly linked to environmental features than that of P. vivax malaria, within these buffers. The incidence of P. falciparum malaria in children was strongly correlated with proportions of bare soil (r = -0.69), land under high vegetation (r = 0.68) and primary forest (r = 0.54), landscape division (r = 0.48) and the number of inhabited houses (r = -0.60). The incidence of P. vivax malaria was associated only with landscape

Standardization of glycohemoglobin results and reference values in whole blood studied in 103 laboratories using 20 methods.

PubMed

Weykamp, C W; Penders, T J; Miedema, K; Muskiet, F A; van der Slik, W

1995-01-01

We investigated the effect of calibration with lyophilized calibrators on whole-blood glycohemoglobin (glyHb) results. One hundred three laboratories, using 20 different methods, determined glyHb in two lyophilized calibrators and two whole-blood samples. For whole-blood samples with low (5%) and high (9%) glyHb percentages, respectively, calibration decreased overall interlaboratory variation (CV) from 16% to 9% and from 11% to 6% and decreased intermethod variation from 14% to 6% and from 12% to 5%. Forty-seven laboratories, using 14 different methods, determined mean glyHb percentages in self-selected groups of 10 nondiabetic volunteers each. With calibration their overall mean (2SD) was 5.0% (0.5%), very close to the 5.0% (0.3%) derived from the reference method used in the Diabetes Control and Complications Trial. In both experiments the Abbott IMx and Vision showed deviating results. We conclude that, irrespective of the analytical method used, calibration enables standardization of glyHb results, reference values, and interpretation criteria.

Usefulness of laboratory methods in diagnosis of pertussis in adult with paroxysmal cough.

PubMed

Piekarska, Katarzyna; Rzeczkowska, Magdalena; Rastawicki, Waldemar; Dąbrowska-Iwanicka, Anna; Paradowska-Stankiewicz, Iwona

2014-01-01

Pertussis is an acute, highly contagious bacterial infection of respiratory system caused by Bordetella pertussis. Principally, disease affects young children, however, recently it is also reported in adolescents and adults. Symptoms of pertussis in adults are non-specific, i.e. dry, paroxysmal and protracted cough. Thus, it is rarely diagnosed in this group. This paper aimed at evaluating the usefulness of the laboratory methods in diagnosis of pertussis in adults based on a case presenting with dry, paroxysmal and chronic cough. Sputum (collected on 25th January 2013) and paired serum samples (collected on 13th February and 19 April 2013) were tested. Pertussis diagnostics involved culture, in-house PCR, real-time PCR and ELISA. Sputum culture, using commercial medium Bordetella Selective Medium by Oxoid did not reveal the presence of B. pertussis. Real-time PCR and PCR, however, confirmed the presence of insertion sequence IS481 and pertussis toxin promoter sequence ptx-Pr, markers indicative of B. pertussis infection. Serological testing revealed the high titres of IgA, IgG and IgM antibodies to B. pertussis in the first sample. In the second sample, collected 2 months following the first one, a significant decrease in IgA antibodies was reported. These data suggest a high usefulness of the laboratory methods in the diagnosis of pertussis in adults with chronic cough. Application of such methods ensures adequate diagnosis of disease, quick introduction of proper treatment and implementation of procedures preventing the spread of infection.

Research and Development Project Selection Methods at the Air Force Wright Aeronautical Laboratories.

DTIC Science & Technology

1985-09-01

personal and telephone interviews. Ten individuals from each of the four AFWAL Laboratories were interrviewed. The results illustrated that few of the...680). Aaker and Tyebee. 1978. The authors constructed a model that dealt with the selection of interdependent R&D projects. The model covers three...of this research effort. Scope * The data collection method used in this study consisted of a combination of personal and telephone interviews. The

Potential of Sr isotopic analysis in ceramic provenance studies: Characterisation of Chinese stonewares

NASA Astrophysics Data System (ADS)

Li, Bao-Ping; Zhao, Jian-Xin; Greig, Alan; Collerson, Kenneth D.; Zhuo, Zhen-Xi; Feng, Yue-Xin

2005-11-01

We compare the trace element and Sr isotopic compositions of stoneware bodies made in Yaozhou and Jizhou to characterise these Chinese archaeological ceramics and examine the potential of Sr isotopes in provenance studies. Element concentrations determined by ICP-MS achieve distinct characterisation for Jizhou samples due to their restricted variation, yet had limited success with Yaozhou wares because of their large variability. In contrast, 87Sr/86Sr ratios in Yaozhou samples have a very small variation and are all significantly lower than those of Jizhou samples, which show a large variation and cannot be well characterised with Sr isotopes. Geochemical interpretation reveals that 87Sr/86Sr ratios will have greater potential to characterise ceramics made of low Rb/Sr materials such as kaolin clay, yet will show larger variations in ceramics made of high Rb/Sr materials such as porcelain stone.

Cost analysis in the toxicology laboratory.

PubMed

Travers, E M

1990-09-01

The process of determining laboratory sectional and departmental costs and test costs for instrument-generated and manually generated reportable results for toxicology laboratories has been outlined in this article. It is hoped that the basic principles outlined in the preceding text will clarify and elucidate one of the most important areas needed for laboratory fiscal integrity and its survival in these difficult times for health care providers. The following general principles derived from this article are helpful aids for managers of toxicology laboratories. 1. To manage a cost-effective, efficient toxicology laboratory, several factors must be considered: the laboratory's instrument configuration, test turnaround time needs, the test menu offered, the analytic methods used, the cost of labor based on time expended and the experience and educational level of the staff, and logistics that determine specimen delivery time and costs. 2. There is a wide variation in costs for toxicologic methods, which requires that an analysis of capital (equipment) purchase and operational (test performance) costs be performed to avoid waste, purchase wisely, and determine which tests consume the majority of the laboratory's resources. 3. Toxicologic analysis is composed of many complex steps. Each step must be individually cost-accounted. Screening test results must be confirmed, and the cost for both steps must be included in the cost per reportable result. 4. Total costs will vary in the same laboratory and between laboratories based on differences in salaries paid to technical staff, differences in reagent/supply costs, the number of technical staff needed to operate the analyzer or perform the method, and the inefficient use of highly paid staff to operate the analyzer or perform the method. 5. Since direct test costs vary directly with the type and number of analyzers or methods and are dependent on the operational mode designed by the manufacturer, laboratory managers

Preservice laboratory education strengthening enhances sustainable laboratory workforce in Ethiopia

PubMed Central

2013-01-01

Background There is a severe healthcare workforce shortage in sub Saharan Africa, which threatens achieving the Millennium Development Goals and attaining an AIDS-free generation. The strength of a healthcare system depends on the skills, competencies, values and availability of its workforce. A well-trained and competent laboratory technologist ensures accurate and reliable results for use in prevention, diagnosis, care and treatment of diseases. Methods An assessment of existing preservice education of five medical laboratory schools, followed by remedial intervention and monitoring was conducted. The remedial interventions included 1) standardizing curriculum and implementation; 2) training faculty staff on pedagogical methods and quality management systems; 3) providing teaching materials; and 4) procuring equipment for teaching laboratories to provide practical skills to complement didactic education. Results A total of 2,230 undergraduate students from the five universities benefitted from the standardized curriculum. University of Gondar accounted for 252 of 2,230 (11.3%) of the students, Addis Ababa University for 663 (29.7%), Jimma University for 649 (29.1%), Haramaya University for 429 (19.2%) and Hawassa University for 237 (10.6%) of the students. Together the universities graduated 388 and 312 laboratory technologists in 2010/2011 and 2011/2012 academic year, respectively. Practical hands-on training and experience with well-equipped laboratories enhanced and ensured skilled, confident and competent laboratory technologists upon graduation. Conclusions Strengthening preservice laboratory education is feasible in resource-limited settings, and emphasizing its merits (ample local capacity, country ownership and sustainability) provides a valuable source of competent laboratory technologists to relieve an overstretched healthcare system. PMID:24164781

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; in-bottle acid digestion of whole-water samples

USGS Publications Warehouse

Hoffman, G.L.; Fishman, M. J.; Garbarino, J.R.

1996-01-01

Water samples for trace-metal determinations routinely have been prepared in open laboratories. For example, the U.S. Geological Survey method I-3485-85 (Extraction Procedure, for Water- Suspended Sediment) is performed in a laboratory hood on a laboratory bench without any special precautions to control airborne contamination. This method tends to be contamination prone for several trace metals primarily because the samples are transferred, acidified, digested, and filtered in an open laboratory environment. To reduce trace-metal contamination of digested water samples, procedures were established that rely on minimizing sample-transfer steps and using a class-100 clean bench during sample filtration. This new procedure involves the following steps: 1. The sample is acidified with HCl directly in the original water-sample bottle. 2. The water-sample bottle with the cap secured is heated in a laboratory oven. 3. The digestate is filtered in a class-100 laminar-flow clean bench. The exact conditions used (that is, oven temperature, time of heating, and filtration methods) for this digestion procedure are described. Comparisons between the previous U.S Geological Survey open-beaker method I-3485-85 and the new in-bottle procedure for synthetic and field-collected water samples are given. When the new procedure is used, blank concentrations for most trace metals determined are reduced significantly.

Characterising Wildlife Trade Market Supply-Demand Dynamics

PubMed Central

Rowcliffe, M.; Cowlishaw, G.; Alexander, J. S.; Ntiamoa-Baidu, Y.; Brenya, A.; Milner-Gulland, E. J.

2016-01-01

The trade in wildlife products can represent an important source of income for poor people, but also threaten wildlife locally, regionally and internationally. Bushmeat provides livelihoods for hunters, traders and sellers, protein to rural and urban consumers, and has depleted the populations of many tropical forest species. Management interventions can be targeted towards the consumers or suppliers of wildlife products. There has been a general assumption in the bushmeat literature that the urban trade is driven by consumer demand with hunters simply fulfilling this demand. Using the urban bushmeat trade in the city of Kumasi, Ghana, as a case study, we use a range of datasets to explore the processes driving the urban bushmeat trade. We characterise the nature of supply and demand by explicitly considering three market attributes: resource condition, hunter behaviour, and consumer behaviour. Our results suggest that bushmeat resources around Kumasi are becoming increasingly depleted and are unable to meet demand, that hunters move in and out of the trade independently of price signals generated by the market, and that, for the Kumasi bushmeat system, consumption levels are driven not by consumer choice but by shortfalls in supply and consequent price responses. Together, these results indicate that supply-side processes dominate the urban bushmeat trade in Kumasi. This suggests that future management interventions should focus on changing hunter behaviour, although complementary interventions targeting consumer demand are also likely to be necessary in the long term. Our approach represents a structured and repeatable method to assessing market dynamics in information-poor systems. The findings serve as a caution against assuming that wildlife markets are demand driven, and highlight the value of characterising market dynamics to inform appropriate management. PMID:27632169

Characterising Wildlife Trade Market Supply-Demand Dynamics.

PubMed

McNamara, J; Rowcliffe, M; Cowlishaw, G; Alexander, J S; Ntiamoa-Baidu, Y; Brenya, A; Milner-Gulland, E J

2016-01-01

The trade in wildlife products can represent an important source of income for poor people, but also threaten wildlife locally, regionally and internationally. Bushmeat provides livelihoods for hunters, traders and sellers, protein to rural and urban consumers, and has depleted the populations of many tropical forest species. Management interventions can be targeted towards the consumers or suppliers of wildlife products. There has been a general assumption in the bushmeat literature that the urban trade is driven by consumer demand with hunters simply fulfilling this demand. Using the urban bushmeat trade in the city of Kumasi, Ghana, as a case study, we use a range of datasets to explore the processes driving the urban bushmeat trade. We characterise the nature of supply and demand by explicitly considering three market attributes: resource condition, hunter behaviour, and consumer behaviour. Our results suggest that bushmeat resources around Kumasi are becoming increasingly depleted and are unable to meet demand, that hunters move in and out of the trade independently of price signals generated by the market, and that, for the Kumasi bushmeat system, consumption levels are driven not by consumer choice but by shortfalls in supply and consequent price responses. Together, these results indicate that supply-side processes dominate the urban bushmeat trade in Kumasi. This suggests that future management interventions should focus on changing hunter behaviour, although complementary interventions targeting consumer demand are also likely to be necessary in the long term. Our approach represents a structured and repeatable method to assessing market dynamics in information-poor systems. The findings serve as a caution against assuming that wildlife markets are demand driven, and highlight the value of characterising market dynamics to inform appropriate management.

Japanese Society for Laboratory Hematology flow cytometric reference method of determining the differential leukocyte count: external quality assurance using fresh blood samples.

PubMed

Kawai, Y; Nagai, Y; Ogawa, E; Kondo, H

2017-04-01

To provide target values for the manufacturers' survey of the Japanese Society for Laboratory Hematology (JSLH), accurate standard data from healthy volunteers were needed for the five-part differential leukocyte count. To obtain such data, JSLH required an antibody panel that achieved high specificity (particularly for mononuclear cells) using simple gating procedures. We developed a flow cytometric method for determining the differential leukocyte count (JSLH-Diff) and validated it by comparison with the flow cytometric differential leukocyte count of the International Council for Standardization in Haematology (ICSH-Diff) and the manual differential count obtained by microscopy (Manual-Diff). First, the reference laboratory performed an imprecision study of JSLH-Diff and ICSH-Diff, as well as performing comparison among JSLH-Diff, Manual-Diff, and ICSH-Diff. Then two reference laboratories and seven participating laboratories performed imprecision and accuracy studies of JSLH-Diff, Manual-Diff, and ICSH-Diff. Simultaneously, six manufacturers' laboratories provided their own representative values by using automated hematology analyzers. The precision of both JSLH-Diff and ICSH-Diff methods was adequate. Comparison by the reference laboratory showed that all correlation coefficients, slopes and intercepts obtained by the JSLH-Diff, ICSH-Diff, and Manual-Diff methods conformed to the criteria. When the imprecision and accuracy of JSLH-Diff were assessed at seven laboratories, the CV% for lymphocytes, neutrophils, monocytes, eosinophils, and basophils was 0.5~0.9%, 0.3~0.7%, 1.7~2.6%, 3.0~7.9%, and 3.8~10.4%, respectively. More than 99% of CD45 positive leukocytes were identified as normal leukocytes by JSLH-Diff. When JSLH-Diff method were validated by comparison with Manual-Diff and ICSH-Diff, JSLH-Diff showed good performance as a reference method. © 2016 John Wiley & Sons Ltd.

Changes in Ultrasonic Velocity from Fluid Substitution, Calculated with Laboratory Methods, Digital Rock Physics, and Biot Theory

NASA Astrophysics Data System (ADS)

Goldfarb, E. J.; Ikeda, K.; Tisato, N.

2017-12-01

Seismic and ultrasonic velocities of rocks are function of several variables including fluid saturation and type. Understanding the effect of each variable on elastic waves can be valuable when using seismic methods for subsurface modeling. Fluid type and saturation are of specific interest to volcanology, water, and hydrocarbon exploration. Laboratory testing is often employed to understand the effects of fluids on elastic waves. However, laboratory testing is expensive and time consuming. It normally requires cutting rare samples into regular shapes. Fluid injection can also destroy specimens as removing the fluid after testing can prove difficult. Another option is theoretical modeling, which can be used to predict the effect of fluids on elastic properties, but it is often inaccurate. Alternatively, digital rock physics (DRP) can be used to investigate the effect of fluid substitution. DRP has the benefit of being non invasive, as it does not require regular sample shapes or fluid injection. Here, we compare the three methods for dry and saturated Berea sandstone to test the reliability of DRP. First, ultrasonic velocities were obtained from laboratory testing. Second, for comparison, we used a purely theoretical approach - i.e., Hashin-Shtrikman and Biot theory - to estimate the wave speeds at dry and wet conditions. Third, we used DRP. The dry sample was scanned with micro Computed Tomography (µCT), and a three dimensional (3D) array was recorded. We employed a segmentation-less method to convert each 3D array value to density, porosity, elastic moduli, and wave speeds. Wave propagation was simulated numerically at similar frequency as the laboratory. To simulate fluid substitution, we numerically substituted air values for water and repeated the simulation. The results from DRP yielded similar velocities to the laboratory, and accurately predicted the velocity change from fluid substitution. Theoretical modeling could not accurately predict velocity, and

A simple method for plasma total vitamin C analysis suitable for routine clinical laboratory use.

PubMed

Robitaille, Line; Hoffer, L John

2016-04-21

In-hospital hypovitaminosis C is highly prevalent but almost completely unrecognized. Medical awareness of this potentially important disorder is hindered by the inability of most hospital laboratories to determine plasma vitamin C concentrations. The availability of a simple, reliable method for analyzing plasma vitamin C could increase opportunities for routine plasma vitamin C analysis in clinical medicine. Plasma vitamin C can be analyzed by high performance liquid chromatography (HPLC) with electrochemical (EC) or ultraviolet (UV) light detection. We modified existing UV-HPLC methods for plasma total vitamin C analysis (the sum of ascorbic and dehydroascorbic acid) to develop a simple, constant-low-pH sample reduction procedure followed by isocratic reverse-phase HPLC separation using a purely aqueous low-pH non-buffered mobile phase. Although EC-HPLC is widely recommended over UV-HPLC for plasma total vitamin C analysis, the two methods have never been directly compared. We formally compared the simplified UV-HPLC method with EC-HPLC in 80 consecutive clinical samples. The simplified UV-HPLC method was less expensive, easier to set up, required fewer reagents and no pH adjustments, and demonstrated greater sample stability than many existing methods for plasma vitamin C analysis. When compared with the gold-standard EC-HPLC method in 80 consecutive clinical samples exhibiting a wide range of plasma vitamin C concentrations, it performed equivalently. The easy set up, simplicity and sensitivity of the plasma vitamin C analysis method described here could make it practical in a normally equipped hospital laboratory. Unlike any prior UV-HPLC method for plasma total vitamin C analysis, it was rigorously compared with the gold-standard EC-HPLC method and performed equivalently. Adoption of this method could increase the availability of plasma vitamin C analysis in clinical medicine.

Clinical characterisation of pneumonia caused by atypical pathogens combining classic and novel predictors.

PubMed

Masiá, M; Gutiérrez, F; Padilla, S; Soldán, B; Mirete, C; Shum, C; Hernández, I; Royo, G; Martin-Hidalgo, A

2007-02-01

The aim of this study was to characterise community-acquired pneumonia (CAP) caused by atypical pathogens by combining distinctive clinical and epidemiological features and novel biological markers. A population-based prospective study of consecutive patients with CAP included investigation of biomarkers of bacterial infection, e.g., procalcitonin, C-reactive protein and lipopolysaccharide-binding protein (LBP) levels. Clinical, radiological and laboratory data for patients with CAP caused by atypical pathogens were compared by univariate and multivariate analysis with data for patients with typical pathogens and patients from whom no organisms were identified. Two predictive scoring models were developed with the most discriminatory variables from multivariate analysis. Of 493 patients, 94 had CAP caused by atypical pathogens. According to multivariate analysis, patients with atypical pneumonia were more likely to have normal white blood cell counts, have repetitive air-conditioning exposure, be aged <65 years, have elevated aspartate aminotransferase levels, have been exposed to birds, and have lower serum levels of LBP. Two different scoring systems were developed that predicted atypical pathogens with sensitivities of 35.2% and 48.8%, and specificities of 93% and 91%, respectively. The combination of selected patient characteristics and laboratory data identified up to half of the cases of atypical pneumonia with high specificity, which should help clinicians to optimise initial empirical therapy for CAP.

A new order-theoretic characterisation of the polytime computable functions☆

PubMed Central

Avanzini, Martin; Eguchi, Naohi; Moser, Georg

2015-01-01

We propose a new order-theoretic characterisation of the class of polytime computable functions. To this avail we define the small polynomial path order (sPOP⁎ for short). This termination order entails a new syntactic method to analyse the innermost runtime complexity of term rewrite systems fully automatically: for any rewrite system compatible with sPOP⁎ that employs recursion up to depth d, the (innermost) runtime complexity is polynomially bounded of degree d. This bound is tight. Thus we obtain a direct correspondence between a syntactic (and easily verifiable) condition of a program and the asymptotic worst-case complexity of the program. PMID:26412933

Advances in Behavioral Laboratory Methods that Inform Tobacco Regulatory Science: A TCORS Working Group Special Issue

PubMed Central

Wright, M. Jerry; Valentine, Gerald

2017-01-01

Objective The 2009 Family Smoking Prevention and Tobacco Control Act (TCA) created unprecented enabling conditions for establishing national regulatory policy that reduces the burden of public health and societal problems associated with tobacco product use. The Center for Tobacco Products (CTP), created by the FDA to implement the TCA, developed a first-of-its-kind FDA/National Institutes of Health (NIH) collaborative program to fund Tobacco Centers of Regulatory Science (TCORS). Methods To assist the TCORS with addressing research priorites, working groups (WGs) comprised of FDA-CTP liasions and TCORS investigators were formed. Under the direction of the Center for Evaluation and Coordination of Trainin and Research (CECTR), the TCORS WGs seek to develop tangible work products in their respective areas of focus. Results The focus of the behavioral pharmacology WG evolved from publishing a narrow paper on behavioral methods in electronic cigarette research to a collection of papers on advances in behavioral laboratory methods that may inform tobacco regulatory science. Conclusion This Special Issue contains articles that address all of the CTP research priorities and demonstrates how advances in behavioral laboratory methods made by TCORS investigators can inform FDA efforst to regulate tobacco products. PMID:29152546

Skylab mobile laboratory

NASA Technical Reports Server (NTRS)

Primeaux, G. R.; Larue, M. A.

1975-01-01

The Skylab mobile laboratory was designed to provide the capability to obtain necessary data on the Skylab crewmen 30 days before lift-off, within 1 hour after recovery, and until preflight physiological baselines were reattained. The mobile laboratory complex consisted of six laboratories that supported cardiovascular, metabolic, nutrition and endocrinology, operational medicine, blood, and microbiology experiments; a utility package; and two shipping containers. The objectives and equipment requirements of the Skylab mobile laboratory and the data acquisition systems are discussed along with processes such as permanently mounting equipment in the individual laboratories and methods of testing and transporting the units. The operational performance, in terms of amounts of data collected, and the concept of mobile laboratories for medical and scientific experiments are evaluated. The Skylab mobile laboratory succeeded in facilitating the data collection and sample preservation associated with the three Skylab manned flights.

Characterisation of a major phytoplankton bloom in the River Thames (UK) using flow cytometry and high performance liquid chromatography.

PubMed

Moorhouse, H L; Read, D S; McGowan, S; Wagner, M; Roberts, C; Armstrong, L K; Nicholls, D J E; Wickham, H D; Hutchins, M G; Bowes, M J

2018-05-15

Recent river studies have observed rapid phytoplankton dynamics, driven by diurnal cycling and short-term responses to storm events, highlighting the need to adopt new high-frequency characterisation methods to understand these complex ecological systems. This study utilised two such analytical methods; pigment analysis by high performance liquid chromatography (HPLC) and cell counting by flow cytometry (FCM), alongside traditional chlorophyll spectrophotometry and light microscopy screening, to characterise the major phytoplankton bloom of 2015 in the River Thames, UK. All analytical techniques observed a rapid increase in chlorophyll a concentration and cell abundances from March to early June, caused primarily by a diatom bloom. Light microscopy identified a shift from pennate to centric diatoms during this period. The initial diatom bloom coincided with increased HPLC peridinin concentrations, indicating the presence of dinoflagellates which were likely to be consuming the diatom population. The diatom bloom declined rapidly in early June, coinciding with a storm event. There were low chlorophyll a concentrations (by both HPLC and spectrophotometric methods) throughout July and August, implying low biomass and phytoplankton activity. However, FCM revealed high abundances of pico-chlorophytes and cyanobacteria through July and August, showing that phytoplankton communities remain active and abundant throughout the summer period. In combination, these techniques are able to simultaneously characterise a wider range of phytoplankton groups, with greater certainty, and provide improved understanding of phytoplankton functioning (e.g. production of UV inhibiting pigments by cyanobacteria in response to high light levels) and ecological status (through examination of pigment degradation products). Combined HPLC and FCM analyses offer rapid and cost-effective characterisation of phytoplankton communities at appropriate timescales. This will allow a more-targeted use

Characterisation of methicillin-resistant Staphylococcus aureus clinical isolates from animals in New Zealand, 2012-2013, and subclinical colonisation in dogs and cats in Auckland.

PubMed

Karkaba, A; Benschop, J; Hill, K E; Grinberg, A

2017-03-01

To characterise methicillin-resistant Staphylococcus aureus (MRSA) isolates from infection sites in animals in New Zealand and assess the prevalence of subclinical MRSA colonisation in dogs and cats attending veterinary clinics in Auckland. MRSA isolates from clinical specimens obtained by the main New Zealand veterinary diagnostic laboratories between June 2012 and June 2013, were genotypically characterised by DNA microarray hybridisation analysis and spa typing. In addition, nasal or perineal skin swabs collected from a cross-sectional sample of dogs (n=361) and cats (n=225) attending 29 veterinary clinics in Auckland during the same period were analysed for MRSA by culture. Eight MRSA clinical isolates were submitted for characterisation by the participating laboratories. The isolates originated from five dogs, including two isolates from the same dog, one foal, and one isolate had no identification of the source. The strain-types identified were AK3 (ST-5 SCCmecIV t045; n=1), USA500 (ST8 SCCmecIV t064; n=1), WSPP (ST30 SCCmecIV t019; n=1), Rhine Hesse (ST5 SCCmecII t002; n=2), and EMRSA-15 (ST22 SCCmecIV t032; n=3). No MRSA were isolated from 586 cultured swabs. Methicillin-susceptible S. aureus were detected in 9/257 (3.5%) swabs and non-aureus staphylococci in 22/257 (8.5%) swabs. The estimated true MRSA subclinical colonisation prevalence was 0%, with an upper 95% CI boundary of 1.9% for cats and 1.4% for dogs. The modest number of MRSA isolates submitted for this study by the participating laboratories suggests clinical MRSA infection in animals in New Zealand continues to be sporadic. The wide variety of strain-types found mirrored the evolving strain-type diversity observed in humans. We cannot rule out bias due to the non-random sampling of dogs and cats, but the apparent colonisation prevalence of 0% was consistent with the low prevalence of subclinical colonisation in humans in New Zealand. These similarities indicate the epidemiology of animal and

Cloning, expression, purification, and characterisation of the HEAT-repeat domain of TOR from the thermophilic eukaryote Chaetomium thermophilum.

PubMed

Robinson, Graham C; Vegunta, Yogesh; Gabus, Caroline; Gaubitz, Christl; Thore, Stéphane

2017-05-01

The Target of Rapamycin Complex is a central controller of cell growth and differentiation in eukaryotes. Its global architecture has been described by cryoelectron microscopy, and regions of its central TOR protein have been described by X-ray crystallography. However, the N-terminal region of this protein, which consists of a series of HEAT repeats, remains uncharacterised at high resolution, most likely due to the absence of a suitable purification procedure. Here, we present a robust method for the preparation of the HEAT-repeat domain, utilizing the thermophilic fungus Chaetomium thermophilum as a source organism. We describe construct design and stable expression in insect cells. An efficient two-step purification procedure is presented, and the purified product is characterised by SEC and MALDI-TOF MS. The methods described pave the way for a complete high-resolution characterisation of this elusive region of the TOR protein. Copyright © 2017 Elsevier Inc. All rights reserved.

Asymmetrical flow field-flow fractionation for human serum albumin based nanoparticle characterisation and a deeper insight into particle formation processes.

PubMed

John, C; Langer, K

2014-06-13

Nanoparticles used as drug delivery systems are of growing interest in the pharmaceutical field. Understanding the behaviour and effects of nanosystems in the human body is dependent on comprehensive characterisation of the systems especially with regard to size and size distribution. Asymmetrical flow field-flow fractionation (AF4) is a promising method for this challenge as this technique enables chromatographic separation of particles and solute molecules according to their respective size. Within this study AF4 was used for the characterisation of human serum albumin (HSA) based nanoparticles. In a first part, the most important aspects of method development like the choice of cross flow rate, focusing and the increase of sample concentration via outlet stream splitting on the sample separation were evaluated. Sample fractionation was controlled by inline-coupling of a dynamic light scattering detector (DLS, Zetasizer) and was confirmed by DLS batch mode measurements. In a second part the applicability of field-flow fractionation for characterisation of the HSA particle formation process by a desolvation method was evaluated. A time dependent particle formation was observed which was controlled by the amount of desolvating agent. Furthermore, field-flow fractionation in combination with in-line dynamic light scattering was used to monitor the increase of particle diameter during PEGylation of the resulting HSA nanoparticles. The separation of nanoparticles from dissolved polyethylene glycol (PEG) could successfully be used for determination of the particles' PEGylation degree. Copyright © 2014 Elsevier B.V. All rights reserved.

[An evaluation of the effectiveness of laboratory diagnostic methods for brucellosis].

PubMed

Gandara, B; Zheludkov, M M; Chernysheva, M I

1994-01-01

The diagnostic value of bacteriological and serological methods for the laboratory diagnosis of brucellosis was studied. In the analysis of milk and cheese specimens Brucella cultures were isolated and differentiated as B.melitensis, biovar I, and B.abortus, biovar 4. In 25.6% of cases B.melitensis culture, biovar 1, was isolated from the blood of persons suspected for brucellosis. The isolation of B.melitensis culture from milk showed that this infective agent migrated from small animals to cattle, which was indicative of a high risk of human infection in the state of Zacatecas, Mexico. The comparative evaluation of serological diagnostic methods (the agglutination test in test tubes, Huddleson's slide test, the acidic rose bengal test and the 2-mercaptoethanol test) showed high sensitivity of rapid tests (Huddleson's test and the rose bengal test in 93.7% and 87.9% of cases respectively). The 2-mercaptoethanol test which gave positive results in 63.8% of cases provided additional information characterizing the course of infections process.

Towards the development of laboratory methods for studying drinking games: Initial findings, methodological considerations, and future directions

PubMed Central

Silvestri, Mark M.; Lewis, Jennifer M.; Borsari, Brian; Correia, Christopher J.

2014-01-01

Background Drinking games are prevalent among college students and are associated with increased alcohol use and negative alcohol-related consequences. There has been substantial growth in research on drinking games. However, the majority of published studies rely on retrospective self-reports of behavior and very few studies have made use of laboratory procedures to systematically observe drinking game behavior. Objectives The current paper draws on the authors’ experiences designing and implementing methods for the study of drinking games in the laboratory. Results The paper addressed the following key design features: (a) drinking game selection; (b) beverage selection; (c) standardizing game play; (d) selection of dependent and independent variables; and (e) creating a realistic drinking game environment. Conclusions The goal of this methodological review paper is to encourage other researchers to pursue laboratory research on drinking game behavior. Use of laboratory-based methodologies will facilitate a better understanding of the dynamics of risky drinking and inform prevention and intervention efforts. PMID:25192209

Using nuclear magnetic resonance and transient electromagnetics to characterise water distribution beneath an ice covered volcanic crater: the case of Sherman Crater Mt. Baker Washington.

USGS Publications Warehouse

Irons, Trevor P.; Martin, Kathryn; Finn, Carol A.; Bloss, Benjamin; Horton, Robert J.

2014-01-01

Surface and laboratory Nuclear Magnetic Resonance (NMR) measurements combined with transient electromagnetic (TEM) data are powerful tools for subsurface water detection. Surface NMR (sNMR) and TEM soundings, laboratory NMR, complex resistivity, and X-Ray Diffraction (XRD) analysis were all conducted to characterise the distribution of water within Sherman Crater on Mt. Baker, WA. Clay rich rocks, particularly if water saturated, can weaken volcanoes, thereby increasing the potential for catastrophic sector collapses that can lead to far-travelled, destructive debris flows. Detecting the presence and volume of shallow groundwater is critical for evaluating these landslide hazards. The TEM data identified a low resistivity layer (<10 ohm-m), under 60 m of glacial ice related to water saturated clays. The TEM struggles to resolve the presence or absence of a plausible thin layer of bulk liquid water on top of the clay. The sNMR measurements did not produce any observable signal, indicating the lack of substantial accumulated bulk water below the ice. Laboratory analysis on a sample from the crater wall that likely represented the clays beneath the ice confirmed that the controlling factor for the lack of sNMR signal was the fine-grained nature of the media. The laboratory measurements further indicated that small pores in clays detected by the XRD contain as much as 50% water, establishing an upper bound on the water content in the clay layer. Forward modelling of geologic scenarios revealed that bulk water layers as thin as ½ m between the ice and clay layer would have been detectable using sNMR. The instrumentation conditions which would allow for sNMR detection of the clay layer are investigated. Using current instrumentation the combined analysis of the TEM and sNMR data allow for valuable characterisation of the groundwater system in the crater. The sNMR is able to reduce the uncertainty of the TEM in regards to the presence of a bulk water layer, a valuable

Testing new methodologies and assessing their potential for reservoir characterisation: Geoelectrical studies in the Northwest Carboniferous Basin (Ireland).

NASA Astrophysics Data System (ADS)

Ogaya, Xènia; Campanyà, Joan; Rath, Volker; Jones, Alan G.; Reay, Derek; Raine, Rob; McConnell, Brian; Ledo, Juanjo

2016-04-01

The overarching objective of this study is to improve our methods of characterising saline aquifers by integrating newly acquired electromagnetic data with existing geophysical and geological data. The work presented here is part of an ongoing project to evaluate Ireland's potential for onshore carbon sequestration (IRECCSEM; funded by Science Foundation Ireland). The methodology presented in this characterisation work is not only relevant for studying the potential for onshore carbon sequestration, but is generally applicable for aquifer characterisation, particularly for the evaluation of geothermal resources in appropriate geological settings. We present first results of the three-dimensional (3D) modelling and inversion of the magnetotelluric (MT) data acquired in the Northwest Carboniferous Basin (Ireland) in summer 2015. The electrical resistivity distribution beneath the survey area is constrained using a joint inversion of three different types of electromagnetic data: MT impedance tensor responses (Z), geomagnetic transfer functions (GTF) and inter-station horizontal magnetic transfer-functions (HMT). The preliminary 3D resistivity model obtained reveals the geoelectrical structure of the subsurface, which is translated into parameters relevant to fluid flow. The electromagnetic data were acquired along profiles linking four wells drilled in the area and the available well log data from those wells are used to evaluate some of the existing petrophysical relationships and calibrate them for the study area. This allows us to interpolate the rock physical properties from one well to another well, using the computed geoelectrical model as a reference. The obtained results are compared to available independent geological and geophysical data in order to analyse the validity of this technique, to characterise the uncertainties inherent to our approach, and to assess the potential of this methodology for reservoir characterisation.

Procedures of Exercise Physiology Laboratories

NASA Technical Reports Server (NTRS)

Bishop, Phillip A.; Fortney, Suzanne; Greenisen, Michael; Siconolfi, Steven F.; Bamman, Marcas M.; Moore, Alan D., Jr.; Squires, William

1998-01-01

This manual describes the laboratory methods used to collect flight crew physiological performance data at the Johnson Space Center. The Exercise Countermeasures Project Laboratory is a standard physiology laboratory; only the application to the study of human physiological adaptations to spaceflight is unique. In the absence of any other recently published laboratory manual, this manual should be a useful document staffs and students of other laboratories.

Soil characterisation by bacterial community analysis for forensic applications: A quantitative comparison of environmental technologies.

PubMed

Habtom, Habteab; Demanèche, Sandrine; Dawson, Lorna; Azulay, Chen; Matan, Ofra; Robe, Patrick; Gafny, Ron; Simonet, Pascal; Jurkevitch, Edouard; Pasternak, Zohar

2017-01-01

The ubiquity and transferability of soil makes it a resource for the forensic investigator, as it can provide a link between agents and scenes. However, the information contained in soils, such as chemical compounds, physical particles or biological entities, is seldom used in forensic investigations; due mainly to the associated costs, lack of available expertise, and the lack of soil databases. The microbial DNA in soil is relatively easy to access and analyse, having thus the potential to provide a powerful means for discriminating soil samples or linking them to a common origin. We compared the effectiveness and reliability of multiple methods and genes for bacterial characterisation in the differentiation of soil samples: ribosomal intergenic spacer analysis (RISA), terminal restriction fragment length polymorphism (TRFLP) of the rpoB gene, and five methods using the 16S rRNA gene: phylogenetic microarrays, TRFLP, and high throughput sequencing with Roche 454, Illumina MiSeq and IonTorrent PGM platforms. All these methods were also compared to long-chain hydrocarbons (n-alkanes) and fatty alcohol profiling of the same soil samples. RISA, 16S TRFLP and MiSeq performed best, reliably and significantly discriminating between adjacent, similar soil types. As TRFLP employs the same capillary electrophoresis equipment and procedures used to analyse human DNA, it is readily available for use in most forensic laboratories. TRFLP was optimized for forensic usage in five parameters: choice of primer pair, fluorescent tagging, concentrating DNA after digestion, number of PCR amplifications per sample and number of capillary electrophoresis runs per PCR amplification. This study shows that molecular microbial ecology methodologies are robust in discriminating between soil samples, illustrating their potential usage as an evaluative forensic tool. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

49 CFR 40.185 - Through what methods and to whom must a laboratory report split specimen results?

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 1 2011-10-01 2011-10-01 false Through what methods and to whom must a laboratory report split specimen results? 40.185 Section 40.185 Transportation Office of the Secretary of Transportation PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Split Specimen Tests § 40.185 Through what methods and to whom...

Characterising the material properties at the interface between skin and a skin vaccination microprojection device.

PubMed

Crichton, Michael L; Archer-Jones, Cameron; Meliga, Stefano; Edwards, Grant; Martin, Darren; Huang, Han; Kendall, Mark A F

2016-05-01

The rapid emergence of micro-devices for biomedical applications over the past two decades has introduced new challenges for the materials used in the devices. Devices like microneedles and the Nanopatch, require sufficient strength to puncture skin often with sharp-slender micro-scale profiles, while maintaining mechanical integrity. For these technologies we sought to address two important questions: 1) On the scale at which the device operates, what forces are required to puncture the skin? And 2) What loads can the projections/microneedles withstand prior to failure. First, we used custom fabricated nanoindentation micro-probes to puncture skin at the micrometre scale, and show that puncture forces are ∼0.25-1.75mN for fresh mouse skin, in agreement with finite element simulations for our device. Then, we used two methods to perform strength tests of Nanopatch projections with varied aspect ratios. The first method used a nanoindenter to apply a force directly on the top or on the side of individual silicon projections (110μm in length, 10μm base radius), to measure the force of fracture. Our second method used an Instron to fracture full rows of projections and characterise a range of projection designs (with the method verified against previous nanoindentation experiments). Finally, we used Cryo-Scanning Electron Microscopy to visualise projections in situ in the skin to confirm the behaviour we quantified, qualitatively. Micro-device development has proliferated in the past decade, including devices that interact with tissues for biomedical outcomes. The field of microneedles for vaccine delivery to skin has opened new material challenges both in understanding tissue material properties and device material. In this work we characterise both the biomaterial properties of skin and the material properties of our microprojection vaccine delivery device. This study directly measures the micro-scale puncture properties of skin, whilst demonstrating clearly how

In-depth glycoproteomic characterisation of grape berry vacuolar invertase using a combination of mass spectrometry-based approaches.

PubMed

Hovasse, Agnès; Alayi, Tchilabalo Dilezitoko; Van Dorsselaer, Alain; Marchal, Richard; Jégou, Sandrine; Schaeffer-Reiss, Christine

2016-06-01

Vacuolar invertase is a key enzyme of sugar metabolism in grape berries. A full characterisation of this highly N-glycosylated protein is required to help understand its biological and biochemical significance in grapes. We have developed a mass spectrometry (MS)-based glycoproteomic approach wherein deglycosylated peptides are analysed by LC-MS/MS, while intact glycopeptides are characterised using a dedicated MS method to determine the attachment sites and micro-heterogeneity. For grape invertase, in parallel with deglycosylated peptides analysis, different enzymatic digestions were performed and glycopeptide detection was improved by enrichment method, nanoLC-MS and oxonium glycan ions. This MS-based glycoproteomic approach demonstrates that vacuolar invertase is glycosylated at all twelve potential N-glycosylation sites. Glycosylation is heterogeneous, with twelve glycoforms identified at six of the sites. The identification of several types of N-glycans is a major result to correlate with the surface and foaming properties of wine, the solubility, allergenicity, and protease resistance of wine proteins. Copyright © 2016 Elsevier Ltd. All rights reserved.

ADM1-based methodology for the characterisation of the influent sludge in anaerobic reactors.

PubMed

Huete, E; de Gracia, M; Ayesa, E; Garcia-Heras, J L

2006-01-01

This paper presents a systematic methodology to characterise the influent sludge in terms of the ADM1 components from the experimental measurements traditionally used in wastewater engineering. For this purpose, a complete characterisation of the model components in their elemental mass fractions and charge has been used, making a rigorous mass balance for all the process transformations and enabling the future connection with other unit-process models. It also makes possible the application of mathematical algorithms for the optimal characterisation of several components poorly defined in the ADM1 report. Additionally, decay and disintegration have been necessarily uncoupled so that the decay proceeds directly to hydrolysis instead of producing intermediate composites. The proposed methodology has been applied to the particular experimental work of a pilot-scale CSTR treating real sewage sludge, a mixture of primary and secondary sludge. The results obtained have shown a good characterisation of the influent reflected in good model predictions. However, its limitations for an appropriate prediction of alkalinity and carbon percentages in biogas suggest the convenience of including the elemental characterisation of the process in terms of carbon in the analytical program.

Comparison of laboratory and field remote sensing methods to measure forage quality.

PubMed

Guo, Xulin; Wilmshurst, John F; Li, Zhaoqin

2010-09-01

Recent research in range ecology has emphasized the importance of forage quality as a key indicator of rangeland condition. However, we lack tools to evaluate forage quality at scales appropriate for management. Using canopy reflectance data to measure forage quality has been conducted at both laboratory and field levels separately, but little work has been conducted to evaluate these methods simultaneously. The objective of this study is to find a reliable way of assessing grassland quality through measuring forage chemistry with reflectance. We studied a mixed grass ecosystem in Grasslands National Park of Canada and surrounding pastures, located in southern Saskatchewan. Spectral reflectance was collected at both in-situ field level and in the laboratory. Vegetation samples were collected at each site, sorted into the green grass portion, and then sent to a chemical company for measuring forage quality variables, including protein, lignin, ash, moisture at 135 °C, Neutral Detergent Fiber (NDF), Acid Detergent Fiber (ADF), Total Digestible, Digestible Energy, Net Energy for Lactation, Net Energy for Maintenance, and Net Energy for Gain. Reflectance data were processed with the first derivative transformation and continuum removal method. Correlation analysis was conducted on spectral and forage quality variables. A regression model was further built to investigate the possibility of using canopy spectral measurements to predict the grassland quality. Results indicated that field level prediction of protein of mixed grass species was possible (r² = 0.63). However, the relationship between canopy reflectance and the other forage quality variables was not strong.

THE QUANTIFICATION OF AQUEOUS TRACERS IN LABORATORY AQUIFER MODELS USING A LIGHT TRANSMISSION VISUALIZATION METHOD - 3

EPA Science Inventory

The quantification of solute concentrations in laboratory aquifer models has been largely limited to the use of sampling ports, from which samples are collected for external analysis. One of the drawbacks to this method is that the act of sampling may disturb plume dynamics and ...

THE QUANTIFICATION OF AQUEOUS TRACERS IN LABORATORY AQUIFER MODELS USING A LIGHT TRANSMISSION VISUALIZATION METHOD - 2

EPA Science Inventory

The quantification of solute concentrations in laboratory aquifer models has been largely limited to the use of sampling ports, from which samples are collected for external analysis. One of the drawbacks to this method is that the act of sampling may disturb plume dynamics and ...

THE QUANTIFICATION OF AQUEOUS TRACERS IN LABORATORY AQUIFER MODELS USING A LIGHT TRANSMISSION VISUALIZATION METHOD - 1

EPA Science Inventory

The quantification of solute concentrations in laboratory aquifer models has been largely limited to the use of sampling ports, from which samples are collected for external analysis. One of the drawbacks to this method is that the act of sampling may disturb plume dynamics and ...

Laboratory validation of four black carbon measurement methods for the determination of non-volatile particulate matter (PM) mass emissions . . .

EPA Science Inventory

A laboratory-scale experimental program was designed to standardize each of four black carbon measurement methods, provide appropriate quality assurance/control procedures for these techniques, and compare measurements made by these methods to a NIST traceable standard (filter gr...

Laboratory Methods for the Measurement of Pollutants in Water and Waste Effluents

NASA Technical Reports Server (NTRS)

Ballinger, Dwight G.

1971-01-01

The requirement for accurate, precise, and rapid analytical procedures for the examination of water and waste samples requires the use of a variety of instruments. The instrumentation in water laboratories includes atomic absorption, UV-visible. and infrared spectrophotometers, automatic colorimetric analyzers, gas chromatographs and mass spectrometers. Because of the emphasis on regulatory action, attention is being directed toward quality control of analytical results. Among the challenging problems are the differentiation of metallic species in water at nanogram concentrations, rapid measurement of free cyanide and free ammonia, more sensitive methods for arsenic and selenium and improved characterization of organic contaminants.

Plasma creatinine in dogs: intra- and inter-laboratory variation in 10 European veterinary laboratories

PubMed Central

2011-01-01

Background There is substantial variation in reported reference intervals for canine plasma creatinine among veterinary laboratories, thereby influencing the clinical assessment of analytical results. The aims of the study was to determine the inter- and intra-laboratory variation in plasma creatinine among 10 veterinary laboratories, and to compare results from each laboratory with the upper limit of its reference interval. Methods Samples were collected from 10 healthy dogs, 10 dogs with expected intermediate plasma creatinine concentrations, and 10 dogs with azotemia. Overlap was observed for the first two groups. The 30 samples were divided into 3 batches and shipped in random order by postal delivery for plasma creatinine determination. Statistical testing was performed in accordance with ISO standard methodology. Results Inter- and intra-laboratory variation was clinically acceptable as plasma creatinine values for most samples were usually of the same magnitude. A few extreme outliers caused three laboratories to fail statistical testing for consistency. Laboratory sample means above or below the overall sample mean, did not unequivocally reflect high or low reference intervals in that laboratory. Conclusions In spite of close analytical results, further standardization among laboratories is warranted. The discrepant reference intervals seem to largely reflect different populations used in establishing the reference intervals, rather than analytical variation due to different laboratory methods. PMID:21477356

Mixed methods student evaluation of an online systemic human anatomy course with laboratory.

PubMed

Attardi, Stefanie M; Choi, Suwhan; Barnett, John; Rogers, Kem A

2016-05-06

A fully online section of an existing face-to-face (F2F) systemic human anatomy course with a prosection laboratory was offered for the first time in 2012-2013. Lectures for F2F students (N = 365) were broadcast in both live and archived format to online students (N = 40) using virtual classroom software. Laboratories were delivered online by a teaching assistant who manipulated 3D computer models in the virtual classroom environment. An exploratory sequential mixed methods approach was undertaken to determine the most important deciding factors that drive students' preferences for a given format and then to generate theory on the strengths and weaknesses of the online format. Students (20 online; 310 F2F) volunteered to participate in a crossover period of one week to expose them to the course section in which they were not originally registered. Open ended interviews (20 online; 20 F2F) and quantitative surveys (270 F2F) were conducted following a crossover. Students valued pace control, schedule, and location flexibility of learning from archived materials and being assessed online. In the online laboratory they had difficulty using the 3D models and preferred the unique and hands-on experiences of cadaveric specimens. The F2F environment was conducive to learning in both lecture and laboratory because students felt more engaged by instructors in person and were less distracted by their surroundings. These results suggest the need to improve the online experience by increasing the quality of student-instructor communication and in turn student-content interaction with the 3D models. Anat Sci Educ 9: 272-285. © 2015 American Association of Anatomists. © 2015 American Association of Anatomists.

Characterisation and quantification of phenolic compounds of extra-virgin olive oils according to their geographical origin by a rapid and resolutive LC-ESI-TOF MS method.

PubMed

Ouni, Youssef; Taamalli, Ameni; Gómez-Caravaca, Ana Maria; Segura-Carretero, Antonio; Fernández-Gutiérrez, Alberto; Zarrouk, Mokhtar

2011-08-01

The phenolic compounds present in seven samples of olive fruits were analysed by a rapid and resolutive LC-ESI-TOF MS method. All samples were collected during the normal picking period for olive oil production, in central and south Tunisia, and were obtained from the Oueslati variety cultivated in different olive growing areas. In the Tunisian samples, 22 compounds have been characterised by LC-ESI-TOF MS analysis. Results showed no qualitative differences in the phenolic fractions between virgin olive oils from different geographical region. However, significant quantitative differences were observed in a wide number of phenolic compounds. These results permit to use the phenolic fractions as an indicator of each region. Copyright © 2011 Elsevier Ltd. All rights reserved.

Non-destructive mapping of grain orientations in 3D by laboratory X-ray microscopy

PubMed Central

McDonald, S. A.; Reischig, P.; Holzner, C.; Lauridsen, E. M.; Withers, P. J.; Merkle, A. P.; Feser, M.

2015-01-01

The ability to characterise crystallographic microstructure, non-destructively and in three-dimensions, is a powerful tool for understanding many aspects related to damage and deformation mechanisms in polycrystalline materials. To this end, the technique of X-ray diffraction contrast tomography (DCT) using monochromatic synchrotron and polychromatic laboratory X-ray sources has been shown to be capable of mapping crystal grains and their orientations non-destructively in 3D. Here we describe a novel laboratory-based X-ray DCT modality (LabDCT), enabling the wider accessibility of the DCT technique for routine use and in-depth studies of, for example, temporal changes in crystallographic grain structure non-destructively over time through ‘4D’ in situ time-lapse studies. The capability of the technique is demonstrated by studying a titanium alloy (Ti-β21S) sample. In the current implementation the smallest grains that can be reliably detected are around 40 μm. The individual grain locations and orientations are reconstructed using the LabDCT method and the results are validated against independent measurements from phase contrast tomography and electron backscatter diffraction respectively. Application of the technique promises to provide important insights related to the roles of recrystallization and grain growth on materials properties as well as supporting 3D polycrystalline modelling of materials performance. PMID:26494523

Flow zone characterisation in a fractured aquifer using spring and open-well T and EC monitoring.

NASA Astrophysics Data System (ADS)

Agbotui, Prodeo; West, Landis; Bottrell, Simon

2017-04-01

The Cretaceous Chalk is a very important aquifer in England, and its relatively high transmissivity derives essentially from a well-developed network of solutionally-enhanced fractures and conduits. Like other fractured aquifers, characterisation and delineation of flow pathways and hence catchment boundaries is important. Determination of flow pathways for source catchment delineation (e.g. identification of safeguarding zones around wells) is critical for the effective management and protection of the groundwater resource. It also determines the areal extent of contamination from known sources, and enables the targeted sampling of flow zones e.g. for monitored natural attenuation (MNA). A rather simplistic conceptualisation of the unconfined chalk aquifer of East Yorkshire is currently used as a basis for numerical simulations: linearly reducing hydraulic conductivity (K) with depth below the maximum groundwater elevation, reducing to a minimum value below the zone of groundwater table fluctuation. This study represents an attempt to improve this conceptualisation via improved characterisation of permeable zones within the aquifer. The methods used are: pumping test drawdown analyses for transmissivity, ambient open-well dilution testing; rainfall, groundwater head, and spring / open-well specific electrical conductance (SEC) and temperature monitoring. Pumping test analyses yield overall well transmissivity; the open-well dilution/monitoring approach identifies inflow, outflow, crossflow zones and direction and rate of flow in wells; seasonal changes in flows in wells and springs reflect the annual recharge and recession cycle and the impact of seasonal hydraulic head variation on the activation/deactivation of permeable pathways. Variations in spring and well-water electrical conductivity / temperature provide insight into groundwater residence times and the degree of isolation of groundwater from atmospheric and soil zone sources of CO2. The results of the

Characterising and modelling regolith stratigraphy using multiple geophysical techniques

NASA Astrophysics Data System (ADS)

Thomas, M.; Cremasco, D.; Fotheringham, T.; Hatch, M. A.; Triantifillis, J.; Wilford, J.

2013-12-01

Regolith is the weathered, typically mineral-rich layer from fresh bedrock to land surface. It encompasses soil (A, E and B horizons) that has undergone pedogenesis. Below is the weathered C horizon that retains at least some of the original rocky fabric and structure. At the base of this is the lower regolith boundary of continuous hard bedrock (the R horizon). Regolith may be absent, e.g. at rocky outcrops, or may be many 10's of metres deep. Comparatively little is known about regolith, and critical questions remain regarding composition and characteristics - especially deeper where the challenge of collecting reliable data increases with depth. In Australia research is underway to characterise and map regolith using consistent methods at scales ranging from local (e.g. hillslope) to continental scales. These efforts are driven by many research needs, including Critical Zone modelling and simulation. Pilot research in South Australia using digitally-based environmental correlation techniques modelled the depth to bedrock to 9 m for an upland area of 128 000 ha. One finding was the inability to reliably model local scale depth variations over horizontal distances of 2 - 3 m and vertical distances of 1 - 2 m. The need to better characterise variations in regolith to strengthen models at these fine scales was discussed. Addressing this need, we describe high intensity, ground-based multi-sensor geophysical profiling of three hillslope transects in different regolith-landscape settings to characterise fine resolution (i.e. < 1 m) regolith stratigraphy. The geophysics included: ground penetrating radar collected at a number of frequencies; multiple frequency, multiple coil electromagnetic induction; and high resolution resistivity. These were accompanied by georeferenced, closely spaced deep cores to 9 m - or to core refusal. The intact cores were sub-sampled to standard depths and analysed for regolith properties to compile core datasets consisting of: water content

The instruments in the first psychological laboratory in Mexico: antecedents, influence, and methods.

PubMed

Escobar, Rogelio

2014-11-01

Enrique O. Aragón established the first psychological laboratory in Mexico in 1916. This laboratory was inspired by Wundt's laboratory and by those created afterward in Germany and the United States. It was equipped with state-of-the art instruments imported from Germany in 1902 from Ernst Zimmermann who supplied instruments for Wundt's laboratory. Although previous authors have described the social events leading to the creation of the laboratory, there are limited descriptions of the instruments, their use, and their influence. With the aid of archival resources, the initial location of the laboratory was determined. The analysis of instruments revealed a previously overlooked relation with a previous laboratory of experimental physiology. The influence of the laboratory was traced by describing the careers of 4 students, 3 of them women, who worked with the instruments during the first 2 decades of the 20th century, each becoming accomplished scholars. In addition, this article, by identifying and analyzing the instruments shown in photographs of the psychological laboratory and in 1 motion film, provides information of the class demonstrations and the experiments conducted in this laboratory.

Non-Noble Metal Oxide Catalysts for Methane Catalytic Combustion: Sonochemical Synthesis and Characterisation

PubMed Central

Jędrzejczyk, Roman J.; Dziedzicka, Anna; Kuterasiński, Łukasz; Sitarz, Maciej

2017-01-01

The aim of this study was to obtain nanocrystalline mixed metal-oxide–ZrO2 catalysts via a sonochemically-induced preparation method. The effect of a stabiliser’s addition on the catalyst parameters was investigated by several characterisation methods including X-ray Diffraction (XRD), nitrogen adsorption, X-ray fluorescence (XRF), scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectrometer (EDS), transmission electron microscopy (TEM) and µRaman. The sonochemical preparation method allowed us to manufacture the catalysts with uniformly dispersed metal-oxide nanoparticles at the support surface. The catalytic activity was tested in a methane combustion reaction. The activity of the catalysts prepared by the sonochemical method was higher than that of the reference catalysts prepared by the incipient wetness method without ultrasonic irradiation. The cobalt and chromium mixed zirconia catalysts revealed their high activities, which are comparable with those presented in the literature. PMID:28686190

The application of terahertz pulsed imaging in characterising density distribution of roll-compacted ribbons.

PubMed

Zhang, Jianyi; Pei, Chunlei; Schiano, Serena; Heaps, David; Wu, Chuan-Yu

2016-09-01

Roll compaction is a commonly used dry granulation process in pharmaceutical, fine chemical and agrochemical industries for materials sensitive to heat or moisture. The ribbon density distribution plays an important role in controlling properties of granules (e.g. granule size distribution, porosity and strength). Accurate characterisation of ribbon density distribution is critical in process control and quality assurance. The terahertz imaging system has a great application potential in achieving this as the terahertz radiation has the ability to penetrate most of the pharmaceutical excipients and the refractive index reflects variations in density and chemical compositions. The aim of this study is to explore whether terahertz pulse imaging is a feasible technique for quantifying ribbon density distribution. Ribbons were made of two grades of microcrystalline cellulose (MCC), Avicel PH102 and DG, using a roll compactor at various process conditions and the ribbon density variation was investigated using terahertz imaging and section methods. The density variations obtained from both methods were compared to explore the reliability and accuracy of the terahertz imaging system. An average refractive index is calculated from the refractive index values in the frequency range between 0.5 and 1.5THz. It is shown that the refractive index gradually decreases from the middle of the ribbon towards to the edges. Variations of density distribution across the width of the ribbons are also obtained using both the section method and the terahertz imaging system. It is found that the terahertz imaging results are in excellent agreement with that obtained using the section method, demonstrating that terahertz imaging is a feasible and rapid tool to characterise ribbon density distributions. Copyright © 2016 Elsevier B.V. All rights reserved.

Comparison and Characterisation of Regenerated Chitosan from 1-Butyl-3-methylimidazolium Chloride and Chitosan from Crab Shells

PubMed Central

Arnold, Lyndon

2015-01-01

Chitosan is a biopolymer derived from chitin which is naturally occurring in the exoskeleton of crustaceans. This paper reports dissolution and regeneration of chitosan by directly dissolving in an ionic liquid solvent, 1-butyl-3-methylimidazolium chloride (BMIMCl). This will provide an ideal platform to solubilise these kinds of polymers to achieve the dissolution. The current study dissolved chitosan from crab shell utilising BMIMCl as a solvent and characterised the resultant regenerated polymer. The regenerated chitosan showed increased hydrogen bonding when characterised by Fourier transform infrared (FTIR) spectral analysis. In addition, the study also compared the characteristics of regenerated and generic chitosan. The regenerated chitosan was also evaluated for antimicrobial properties and showed to possess antibacterial features similar to the commercial grade. This method can be utilised in future for blending of polymers with chitosan in a dissolved phase. PMID:26090452

Characterising Extrinsic Challenges Linked to the Design and Implementation of Inquiry-Based Practical Work

NASA Astrophysics Data System (ADS)

Akuma, Fru Vitalis; Callaghan, Ronel

2017-11-01

Inquiry-based science education has been incorporated in science curricula internationally. In this regard, however, many teachers encounter challenges. The challenges have been characterised into those linked to the personal characteristics of these teachers (intrinsic challenges) and others associated with contextual factors (extrinsic challenges). However, this level of characterisation is inadequate in terms of appreciating the complexity of the challenges, tracking of their development, and discovering knowledge within specific categories. Against this background, the purpose of the research presented here was to characterise extrinsic challenges linked to the design and implementation of inquiry-based practical work. In order to do so, we used a conceptual framework of teaching challenges based on Bronfenbrenner's ecological theory of human development. The data gathered using a multi-method case study of practical work in two South African high schools, was analysed by combining the data-driven inductive approach and the deductive a priori template of codes approach in thematic analysis. On this basis, the extrinsic challenges linked to the design and implementation of inquiry-based practical work that participants are confronted with, were found to consist of macrosystem challenges (such as a restrictive curriculum) and microsystem challenges. At the latter level, the challenges are material-related (e.g., lack of science education equipment and materials) or non-material-related (such as time constraints and the lack of access to interactive computer simulations). We have discussed the theory-, practice- and research-based implications of these results in relation to the design and implementation of inquiry-based practical work in South Africa and internationally.

Characterisation of myofibroblasts in fibrovascular tissues of primary and recurrent pterygia

PubMed Central

Touhami, A; Di Pascuale, M A; Kawatika, T; Valle, M Del; Rosa, R H; Dubovy, S; Tseng, S C G

2005-01-01

Aims: To determine the presence and origin of myofibroblasts in pterygia. Methods: 86 specimens including head, body, and fibrovascular tissue from 52 primary and 34 recurrent pterygia and five exenterated eyes without pterygia were searched for the origin of myofibroblasts. All tissues were subjected to haematoxylin and eosin staining, immunohistochemistry using antibodies against alpha smooth muscle actin (α-SMA), desmin, vimentin, and caldesmon, and transmission electron microscopy (TEM). The phenotype of fibroblasts subcultured in a serum free medium from pterygium fibrovascular tissues was characterised by the above antibodies. Bundles of dense fibrous tissues were noted in 86% of the fibrovascular tissue specimens evaluated. Cells within these bundles were characterised as myofibroblasts based on positive staining to α-SMA, but negative to desmin and caldesmon, markers for smooth muscle cells. Interestingly, positive α-SMA staining was also found in the periorbital fibroadipose tissue posterior to Tenon’s capsule near the nasal conjunctiva in all exenterated specimens. All first passage fibroblasts expressed vimentin, some were positive to α-SMA, but all were negative to desmin or caldesmon. Cells in pterygium fibrovascular tissues showed ultrastructural features of intracytoplasmic bundles of microfilaments, consistent with myofibroblastic differentiation. Conclusion: These studies collectively demonstrate the presence of contractile myofibroblasts bundle in pterygia and in the periorbital fibroadipose tissue posterior to Tenon’s capsule of exenterated eyes without pterygium. PMID:15722301

Characterising RNA secondary structure space using information entropy

PubMed Central

2013-01-01

Comparative methods for RNA secondary structure prediction use evolutionary information from RNA alignments to increase prediction accuracy. The model is often described in terms of stochastic context-free grammars (SCFGs), which generate a probability distribution over secondary structures. It is, however, unclear how this probability distribution changes as a function of the input alignment. As prediction programs typically only return a single secondary structure, better characterisation of the underlying probability space of RNA secondary structures is of great interest. In this work, we show how to efficiently compute the information entropy of the probability distribution over RNA secondary structures produced for RNA alignments by a phylo-SCFG, and implement it for the PPfold model. We also discuss interpretations and applications of this quantity, including how it can clarify reasons for low prediction reliability scores. PPfold and its source code are available from http://birc.au.dk/software/ppfold/. PMID:23368905

Studying relationships between environment and malaria incidence in Camopi (French Guiana) through the objective selection of buffer-based landscape characterisations.

PubMed

Stefani, Aurélia; Roux, Emmanuel; Fotsing, Jean-Marie; Carme, Bernard

2011-12-13

Malaria remains a major health problem in French Guiana, with a mean of 3800 cases each year. A previous study in Camopi, an Amerindian village on the Oyapock River, highlighted the major contribution of environmental features to the incidence of malaria attacks. We propose a method for the objective selection of the best multivariate peridomestic landscape characterisation that maximises the chances of identifying relationships between environmental features and malaria incidence, statistically significant and meaningful from an epidemiological point of view. A land-cover map, the hydrological network and the geolocalised inhabited houses were used to characterise the peridomestic landscape in eleven discoid buffers with radii of 50, 100, 200, 300, 400, 500, 600, 700, 800, 900 and 1000 metres. Buffer-based landscape characterisations were first compared in terms of their capacity to discriminate between sites within the geographic space and of their effective multidimensionality in variable space. The Akaike information criterion (AIC) was then used to select the landscape model best explaining the incidences of P. vivax and P. falciparum malaria. Finally, we calculated Pearson correlation coefficients for the relationships between environmental variables and malaria incidence, by species, for the more relevant buffers. The optimal buffers for environmental characterisation had radii of 100 m around houses for P. vivax and 400 m around houses for P. falciparum. The incidence of P. falciparum malaria seemed to be more strongly linked to environmental features than that of P. vivax malaria, within these buffers. The incidence of P. falciparum malaria in children was strongly correlated with proportions of bare soil (r = -0.69), land under high vegetation (r = 0.68) and primary forest (r = 0.54), landscape division (r = 0.48) and the number of inhabited houses (r = -0.60). The incidence of P. vivax malaria was associated only with landscape division (r = 0.49). The

Analytical capabilities and services of Lawrence Livermore Laboratory's General Chemistry Division. [Methods available at Lawrence Livermore

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gutmacher, R.; Crawford, R.

This comprehensive guide to the analytical capabilities of Lawrence Livermore Laboratory's General Chemistry Division describes each analytical method in terms of its principle, field of application, and qualitative and quantitative uses. Also described are the state and quantity of sample required for analysis, processing time, available instrumentation, and responsible personnel.

Characterisation of Dissolved Organic Carbon by Thermal Desorption - Proton Transfer Reaction - Mass Spectrometry

NASA Astrophysics Data System (ADS)

Materić, Dušan; Peacock, Mike; Kent, Matthew; Cook, Sarah; Gauci, Vincent; Röckmann, Thomas; Holzinger, Rupert

2017-04-01

Dissolved organic carbon (DOC) is an integral component of the global carbon cycle. DOC represents an important terrestrial carbon loss as it is broken down both biologically and photochemically, resulting in the release of carbon dioxide (CO2) to the atmosphere. The magnitude of this carbon loss can be affected by land management (e.g. drainage). Furthermore, DOC affects autotrophic and heterotrophic processes in aquatic ecosystems, and, when chlorinated during water treatment, can lead to the release of harmful trihalomethanes. Numerous methods have been used to characterise DOC. The most accessible of these use absorbance and fluorescence properties to make inferences about chemical composition, whilst high-performance size exclusion chromatography can be used to determine apparent molecular weight. XAD fractionation has been extensively used to separate out hydrophilic and hydrophobic components. Thermochemolysis or pyrolysis Gas Chromatography - Mass Spectrometry (GC-MS) give information on molecular properties of DOC, and 13C NMR spectroscopy can provide an insight into the degree of aromaticity. Proton Transfer Reaction - Mass Spectrometry (PTR-MS) is a sensitive, soft ionisation method suitable for qualitative and quantitative analysis of volatile and semi-volatile organic vapours. So far, PTR-MS has been used in various environmental applications such as real-time monitoring of volatile organic compounds (VOCs) emitted from natural and anthropogenic sources, chemical composition measurements of aerosols etc. However, as the method is not compatible with water, it has not been used for analysis of organic traces present in natural water samples. The aim of this work was to develop a method based on thermal desorption PTR-MS to analyse water samples in order to characterise chemical composition of dissolved organic carbon. We developed a clean low-pressure evaporation/sublimation system to remove water from samples and thermal desorption system to introduce

Reference method for detection of Pgp mediated multidrug resistance in human hematological malignancies: a method validated by the laboratories of the French Drug Resistance Network.

PubMed

Huet, S; Marie, J P; Gualde, N; Robert, J

1998-12-15

Multidrug resistance (MDR) associated with overexpression of the MDR1 gene and of its product, P-glycoprotein (Pgp), plays an important role in limiting cancer treatment efficacy. Many studies have investigated Pgp expression in clinical samples of hematological malignancies but failed to give definitive conclusion on its usefulness. One convenient method for fluorescent detection of Pgp in malignant cells is flow cytometry which however gives variable results from a laboratory to another one, partly due to the lack of a reference method rigorously tested. The purpose of this technical note is to describe each step of a reference flow cytometric method. The guidelines for sample handling, staining and analysis have been established both for Pgp detection with monoclonal antibodies directed against extracellular epitopes (MRK16, UIC2 and 4E3), and for Pgp functional activity measurement with Rhodamine 123 as a fluorescent probe. Both methods have been validated on cultured cell lines and clinical samples by 12 laboratories of the French Drug Resistance Network. This cross-validated multicentric study points out crucial steps for the accuracy and reproducibility of the results, like cell viability, data analysis and expression.

Organic Laboratory Experiments.

ERIC Educational Resources Information Center

Smith, Sherrel

1990-01-01

Detailed is a method in which short pieces of teflon tubing may be used for collection tubes for collecting preparative fractions from gas chromatographs. Material preparation, laboratory procedures, and results of this method are discussed. (CW)

The effect of handling method on the mouse grimace scale in two strains of laboratory mice

PubMed Central

Leach, Matthew C

2015-01-01

Pain assessment in laboratory animals is an ethical and legal requirement. The mouse grimace scale (MGS) is a new method of pain assessment deemed to be both accurate and reliable, and observers can be rapidly trained to use it. In order for a new pain assessment technique to be effective, we must ensure that the score awarded by the technique is only influenced by pain and not by other husbandry or non-painful but integral aspects of research protocols. Here, we studied 16 male mice, housed under standard laboratory conditions. Eight mice were randomly assigned to tail handling and eight to tube handling on arrival at the unit. On each occasion the mice were removed from their cage for routine husbandry, they were picked up using their assigned handling method. Photographs of the mouse faces were then scored by treatment-blind observers as per the MGS manual (see Nature Methods 2010, Vol. 7, pp 447–449), and scores from the two groups were compared. There was no significant difference in MGS scores between the mice that had been handled using a tube compared with the tail. Consequently, these methods of handling did not influence the baseline grimace score given, suggesting that these handling techniques are not confounding factors when establishing baseline MGS scores, further validating this technique. PMID:26657061

The effect of handling method on the mouse grimace scale in two strains of laboratory mice.

PubMed

Miller, Amy L; Leach, Matthew C

2016-08-01

Pain assessment in laboratory animals is an ethical and legal requirement. The mouse grimace scale (MGS) is a new method of pain assessment deemed to be both accurate and reliable, and observers can be rapidly trained to use it. In order for a new pain assessment technique to be effective, we must ensure that the score awarded by the technique is only influenced by pain and not by other husbandry or non-painful but integral aspects of research protocols. Here, we studied 16 male mice, housed under standard laboratory conditions. Eight mice were randomly assigned to tail handling and eight to tube handling on arrival at the unit. On each occasion the mice were removed from their cage for routine husbandry, they were picked up using their assigned handling method. Photographs of the mouse faces were then scored by treatment-blind observers as per the MGS manual (see Nature Methods 2010, Vol. 7, pp 447-449), and scores from the two groups were compared. There was no significant difference in MGS scores between the mice that had been handled using a tube compared with the tail. Consequently, these methods of handling did not influence the baseline grimace score given, suggesting that these handling techniques are not confounding factors when establishing baseline MGS scores, further validating this technique. © The Author(s) 2015.

Characterisation of North American Brucella isolates from marine mammals.

PubMed

Whatmore, Adrian M; Dawson, Claire; Muchowski, Jakub; Perrett, Lorraine L; Stubberfield, Emma; Koylass, Mark; Foster, Geoffrey; Davison, Nicholas J; Quance, Christine; Sidor, Inga F; Field, Cara L; St Leger, Judy

2017-01-01

Extension of known ecological niches of Brucella has included the description of two novel species from marine mammals. Brucella pinnipedialis is associated predominantly with seals, while two major Brucella ceti clades, most commonly associated with porpoises or dolphins respectively, have been identified. To date there has been limited characterisation of Brucella isolates obtained from marine mammals outside Northern European waters, including North American waters. To address this gap, and extend knowledge of the global population structure and host associations of these Brucella species, 61 isolates from marine mammals inhabiting North American waters were subject to molecular and phenotypic characterisation enabling comparison with existing European isolates. The majority of isolates represent genotypes previously described in Europe although novel genotypes were identified in both B. ceti clades. Harp seals were found to carry B. pinnipedialis genotypes previously confined to hooded seals among a diverse repertoire of sequence types (STs) associated with this species. For the first time Brucella isolates were characterised from beluga whales and found to represent a number of distinct B. pinnipedialis genotypes. In addition the known host range of ST27 was extended with the identification of this ST from California sea lion samples. Finally the performance of the frequently used diagnostic tool Bruce-ladder, in differentiating B. ceti and B. pinnipedialis, was critically assessed based on improved knowledge of the global population structure of Brucella associated with marine mammals.

Development of solid-state NMR techniques for the characterisation of pharmaceutical compounds

NASA Astrophysics Data System (ADS)

Tatton, Andrew S.

Structural characterisation in the solid state is an important step in understanding the physical and chemical properties of a material. Solid-state NMR techniques applied to solid delivery forms are presented as an alternative to more established structural characterisation methods. The effect of homonuclear decoupling upon heteronuclear couplings is investigated using a combination of experimental and density-matrix simulation results acquired from a 13C-1H spinecho pulse sequence, modulated by scalar couplings. It is found that third-order cross terms under MAS and homonuclear decoupling contribute to strong dephasing effects in the NMR signal. Density-matrix simulations allow access to parameters currently unattainable in experiment, and demonstrate that higher homonuclear decoupling rf nutation frequencies reduce the magnitude of third-order cross terms. 15N-1H spinecho experiments were applied to pharmaceutically relevant samples to differentiate between the number of directly attached protons. Using this method, proton transfer in an acid-base reaction is proven in pharmaceutical salts. The indirect detection of 14N lineshapes via protons obtained using 2D 14N-1H HMQC experiments is presented, where coherence transfer is achieved via heteronuclear through-space dipolar couplings. The importance of fast MAS frequencies is demonstrated, and it is found that increasing the recoupling duration reveals longer range NH proximities. The 2D 14N-1H HMQC method is used to demonstrate the presence of specific hydrogen bonding interactions, and thus aid in identifying molecular association in a cocrystal and an amorphous dispersion. In addition, hydrogen bonding motifs were identified by observing the changes in the 14N quadrupolar parameters between individual molecular components relative to the respective solid delivery form. First-principles calculations of NMR chemical shifts and quadrupolar parameters using the GIPAW method were combined with 14N-1H experimental

The use of digital PCR to improve the application of quantitative molecular diagnostic methods for tuberculosis.

PubMed

Devonshire, Alison S; O'Sullivan, Denise M; Honeyborne, Isobella; Jones, Gerwyn; Karczmarczyk, Maria; Pavšič, Jernej; Gutteridge, Alice; Milavec, Mojca; Mendoza, Pablo; Schimmel, Heinz; Van Heuverswyn, Fran; Gorton, Rebecca; Cirillo, Daniela Maria; Borroni, Emanuele; Harris, Kathryn; Barnard, Marinus; Heydenrych, Anthenette; Ndusilo, Norah; Wallis, Carole L; Pillay, Keshree; Barry, Thomas; Reddington, Kate; Richter, Elvira; Mozioğlu, Erkan; Akyürek, Sema; Yalçınkaya, Burhanettin; Akgoz, Muslum; Žel, Jana; Foy, Carole A; McHugh, Timothy D; Huggett, Jim F

2016-08-03

Real-time PCR (qPCR) based methods, such as the Xpert MTB/RIF, are increasingly being used to diagnose tuberculosis (TB). While qualitative methods are adequate for diagnosis, the therapeutic monitoring of TB patients requires quantitative methods currently performed using smear microscopy. The potential use of quantitative molecular measurements for therapeutic monitoring has been investigated but findings have been variable and inconclusive. The lack of an adequate reference method and reference materials is a barrier to understanding the source of such disagreement. Digital PCR (dPCR) offers the potential for an accurate method for quantification of specific DNA sequences in reference materials which can be used to evaluate quantitative molecular methods for TB treatment monitoring. To assess a novel approach for the development of quality assurance materials we used dPCR to quantify specific DNA sequences in a range of prototype reference materials and evaluated accuracy between different laboratories and instruments. The materials were then also used to evaluate the quantitative performance of qPCR and Xpert MTB/RIF in eight clinical testing laboratories. dPCR was found to provide results in good agreement with the other methods tested and to be highly reproducible between laboratories without calibration even when using different instruments. When the reference materials were analysed with qPCR and Xpert MTB/RIF by clinical laboratories, all laboratories were able to correctly rank the reference materials according to concentration, however there was a marked difference in the measured magnitude. TB is a disease where the quantification of the pathogen could lead to better patient management and qPCR methods offer the potential to rapidly perform such analysis. However, our findings suggest that when precisely characterised materials are used to evaluate qPCR methods, the measurement result variation is too high to determine whether molecular quantification

Digital report in an anatomy laboratory: a new method for team-based dissection, reporting, and evaluation.

PubMed

Oh, Chang-Seok; Kim, Kyong-Jee; Chung, Eilho; Choi, Hong-Joo

2015-04-01

Digital report (DR), a new method for students' dissection report, has been introduced to replace the traditional method in the anatomy laboratory. Laboratory tasks were assigned to groups of five students, and each group was asked to make a DR of their dissection tasks and upload it on the website for the anatomy course developed by the authors' institution. For creating the DR, students were instructed to take photographs of their findings with digital cameras, to mark the orientation and label the structures on the photograph. Students were assessed as a group by evaluating the DR. All the photographs of the DR were saved to construct a database that can be used by the students who will take the anatomy course in the following years. A questionnaire consisting of 14 questions was administered at the end of the anatomy course to evaluate the effectiveness of the DR. The results of the student survey showed that the DR was useful for making the students participate more actively in the teamwork for dissection, and for making dissection reports by referring to the DR made by the students from previous years. The DR was also more helpful for the anatomy teacher to assess student learning in the anatomy laboratory than conventional practical examinations and paper-based dissection reports. DR, a paperless report of team-based dissection, is concurrent with the 'digital' age and is in line with the need for a more systematic and objective evaluation of students' dissection.

Modelling, analysis and validation of microwave techniques for the characterisation of metallic nanoparticles

NASA Astrophysics Data System (ADS)

Sulaimalebbe, Aslam

High Frequency Structure Simulator (HFSS), followed by the electrical characterisation of synthesised Pt NP films using the novel miniature fabricated OCP technique. The results obtained from this technique provided the inspiration to synthesise and evaluate the microwave properties of Au NPs. The findings from this technique provided the motivation to characterise both the Pt and Au NP films using the DR technique. Unlike the OCP technique, the DR method is highly sensitive but the achievable measurement accuracy is limited since this technique does not have broadband frequency capability like the OCP method. The results obtained from the DR technique show a good agreement with the theoretical prediction. In the last phase of this research, a further validation of the aperture admittance models on different types OCP (i.e. RG-405 and RG-402 cables and SMA connector) have been carried out on the developed 3D full wave models using HFSS software, followed by the development of universal models for the aforementioned OCPs based on the same 3D full wave models.

Cosmetics Europe multi-laboratory pre-validation of the SkinEthic™ reconstituted human corneal epithelium test method for the prediction of eye irritation.

PubMed

Alépée, N; Bessou-Touya, S; Cotovio, J; de Smedt, A; de Wever, B; Faller, C; Jones, P; Le Varlet, B; Marrec-Fairley, M; Pfannenbecker, U; Tailhardat, M; van Goethem, F; McNamee, P

2013-08-01

Cosmetics Europe, The Personal Care Association, known as Colipa before 2012, conducted a program of technology transfer and assessment of Within/Between Laboratory (WLV/BLV) reproducibility of the SkinEthic™ Reconstituted Human Corneal Epithelium (HCE) as one of two human reconstructed tissue eye irritation test methods. The SkinEthic™ HCE test method involves two exposure time treatment procedures - one for short time exposure (10 min - SE) and the other for long time exposure (60 min - LE) of tissues to test substance. This paper describes pre-validation studies of the SkinEthic™ HCE test method (SE and LE protocols) as well as the Eye Peptide Reactivity Assay (EPRA). In the SE WLV study, 30 substances were evaluated. A consistent outcome with respect to viability measurement across all runs was observed with all substances showing an SD of less than 18%. In the LE WLV study, 44 out of 45 substances were consistently classified. These data demonstrated a high level of reproducibility within laboratory for both the SE and LE treatment procedures. For the LE BLV, 19 out of 20 substances were consistently classified between the three laboratories, again demonstrating a high level of reproducibility between laboratories. The results for EPRA WLV and BLV studies demonstrated that all substances analysed were categorised similarly and that the method is reproducible. The SkinEthic™ HCE test method entered into the experimental phase of a formal ECVAM validation program in 2010. Copyright © 2013. Published by Elsevier Ltd.

Safety in the Chemical Laboratory: Laboratory Air Quality: Part I. A Concentration Model.

ERIC Educational Resources Information Center

Butcher, Samuel S.; And Others

1985-01-01

Offers a simple model for estimating vapor concentrations in instructional laboratories. Three methods are described for measuring ventilation rates, and the results of measurements in six laboratories are presented. The model should provide a simple screening tool for evaluating worst-case personal exposures. (JN)

[Applying the clustering technique for characterising maintenance outsourcing].

PubMed

Cruz, Antonio M; Usaquén-Perilla, Sandra P; Vanegas-Pabón, Nidia N; Lopera, Carolina

2010-06-01

Using clustering techniques for characterising companies providing health institutions with maintenance services. The study analysed seven pilot areas' equipment inventory (264 medical devices). Clustering techniques were applied using 26 variables. Response time (RT), operation duration (OD), availability and turnaround time (TAT) were amongst the most significant ones. Average biomedical equipment obsolescence value was 0.78. Four service provider clusters were identified: clusters 1 and 3 had better performance, lower TAT, RT and DR values (56 % of the providers coded O, L, C, B, I, S, H, F and G, had 1 to 4 day TAT values: characterised. The cluster technique was effective in identifying the most competitive suppliers.

Extensive characterisation of bioactive phenolic constituents from globe artichoke (Cynara scolymus L.) by HPLC-DAD-ESI-QTOF-MS.

PubMed

Abu-Reidah, Ibrahim M; Arráez-Román, David; Segura-Carretero, Antonio; Fernández-Gutiérrez, Alberto

2013-12-01

The aim of this work was to characterise the phenolic compounds in artichoke (hearts) by using HPLC coupled to DAD-ESI-QTOF-MS, which proved useful in characterising 61 phenolic and other polar compounds. Notably, of the 61 compounds characterised, 34 new phenolic compounds with their isomers have been tentatively characterised in artichoke for the first time, namely: 3 hydroxybenzoic acids, 17 hydroxycinnamic acids, 4 lignans, 7 flavones, 2 flavonols, and 1 phenol derivative. Moreover, a total of 28 isomers of previously described phenolics have also been detected. The data compiled from the qualitative polyphenol characterisation indicate that the artichoke extract analysed (Blanca de Tudela variety) could be regarded as a bioactive functional food and also as a promising source of antioxidant phenolic compounds. Copyright © 2013 Elsevier Ltd. All rights reserved.

Detection and characterisation of Complement protein activity in bovine milk by bactericidal sequestration assay.

PubMed

Maye, Susan; Stanton, Catherine; Fitzgerald, Gerald F; Kelly, Philip M

2015-08-01

While the Complement protein system in human milk is well characterised, there is little information on its presence and activity in bovine milk. Complement forms part of the innate immune system, hence the importance of its contribution during milk ingestion to the overall defences of the neonate. A bactericidal sequestration assay, featuring a Complement sensitive strain, Escherichia coli 0111, originally used to characterise Complement activity in human milk was successfully applied to freshly drawn bovine milk samples, thus, providing an opportunity to compare Complement activities in both human and bovine milks. Although not identical in response, the levels of Complement activity in bovine milk were found to be closely comparable with that of human milk. Differential counts of Esch. coli 0111 after 2 h incubation were 6.20 and 6.06 log CFU/ml, for raw bovine and human milks, respectively - the lower value representing a stronger Complement response. Exposing bovine milk to a range of thermal treatments e.g. 42, 45, 65, 72, 85 or 95 °C for 10 min, progressively inhibited Complement activity by increasing temperature, thus confirming the heat labile nature of this immune protein system. Low level Complement activity was found, however, in 65 and 72 °C heat treated samples and in retailed pasteurised milk which highlights the outer limit to which high temperature, short time (HTST) industrial thermal processes should be applied if retention of activity is a priority. Concentration of Complement in the fat phase was evident following cream separation, and this was also reflected in the further loss of activity recorded in low fat variants of retailed pasteurised milk. Laboratory-based churning of the cream during simulated buttermaking generated an aqueous (buttermilk) phase with higher levels of Complement activity than the fat phase, thus pointing to a likely association with the milk fat globule membrane (MFGM) layer.

Basin Characterisation by Means of Joint Inversion of Electromagnetic Geophysical Data, Borehole Data and Multivariate Statistical Methods: The Loop Head Peninsula, Western Ireland, Case Study

NASA Astrophysics Data System (ADS)

Campanya, J. L.; Ogaya, X.; Jones, A. G.; Rath, V.; McConnell, B.; Haughton, P.; Prada, M.

2016-12-01

The Science Foundation Ireland funded project IRECCSEM project (www.ireccsem.ie) aims to evaluate Ireland's potential for onshore carbon sequestration in saline aquifers by integrating new electromagnetic geophysical data with existing geophysical and geological data. One of the objectives of this component of IRECCSEM is to characterise the subsurface beneath the Loop Head Peninsula (part of Clare Basin, Co. Clare, Ireland), and identify major electrical resistivity structures that can guide an interpretation of the carbon sequestration potential of this area. During the summer of 2014, a magnetotelluric (MT) survey was carried out on the Loop Head Peninsula, and data from a total of 140 sites were acquired, including audio-magnetotelluric (AMT), and broadband magnetotelluric (BBMT). The dataset was used to generate shallow three-dimensional (3-D) electrical resistivity models constraining the subsurface to depths of up to 3.5 km. The three-dimensional (3-D) joint inversions were performed using three different types of electromagnetic data: MT impedance tensor (Z), geomagnetic transfer functions (T), and inter-station horizontal magnetic transfer-functions (H). The interpretation of the results was complemented with second-derivative models of the resulting electrical resistivity models, and a quantitative comparison with borehole data using multivariate statistical methods. Second-derivative models were used to define the main interfaces between the geoelectrical structures, facilitating superior comparison with geological and seismic results, and also reducing the influence of the colour scale when interpreting the results. Specific analysis was performed to compare the extant borehole data with the electrical resistivity model, identifying those structures that are better characterised by the resistivity model. Finally, the electrical resistivity model was also used to propagate some of the physical properties measured in the borehole, when a good relation was

Characterisation of North American Brucella isolates from marine mammals

PubMed Central

Dawson, Claire; Muchowski, Jakub; Perrett, Lorraine L.; Stubberfield, Emma; Koylass, Mark; Foster, Geoffrey; Davison, Nicholas J.; Quance, Christine; Sidor, Inga F.; Field, Cara L.; St. Leger, Judy

2017-01-01

Extension of known ecological niches of Brucella has included the description of two novel species from marine mammals. Brucella pinnipedialis is associated predominantly with seals, while two major Brucella ceti clades, most commonly associated with porpoises or dolphins respectively, have been identified. To date there has been limited characterisation of Brucella isolates obtained from marine mammals outside Northern European waters, including North American waters. To address this gap, and extend knowledge of the global population structure and host associations of these Brucella species, 61 isolates from marine mammals inhabiting North American waters were subject to molecular and phenotypic characterisation enabling comparison with existing European isolates. The majority of isolates represent genotypes previously described in Europe although novel genotypes were identified in both B. ceti clades. Harp seals were found to carry B. pinnipedialis genotypes previously confined to hooded seals among a diverse repertoire of sequence types (STs) associated with this species. For the first time Brucella isolates were characterised from beluga whales and found to represent a number of distinct B. pinnipedialis genotypes. In addition the known host range of ST27 was extended with the identification of this ST from California sea lion samples. Finally the performance of the frequently used diagnostic tool Bruce-ladder, in differentiating B. ceti and B. pinnipedialis, was critically assessed based on improved knowledge of the global population structure of Brucella associated with marine mammals. PMID:28934239

Characterisation of the biochemical methane potential (BMP) of individual material fractions in Danish source-separated organic household waste.

PubMed

Naroznova, Irina; Møller, Jacob; Scheutz, Charlotte

2016-04-01

This study is dedicated to characterising the chemical composition and biochemical methane potential (BMP) of individual material fractions in untreated Danish source-separated organic household waste (SSOHW). First, data on SSOHW in different countries, available in the literature, were evaluated and then, secondly, laboratory analyses for eight organic material fractions comprising Danish SSOHW were conducted. No data were found in the literature that fully covered the objectives of the present study. Based on laboratory analyses, all fractions were assigned according to their specific properties in relation to BMP, protein content, lipids, lignocellulose biofibres and easily degradable carbohydrates (carbohydrates other than lignocellulose biofibres). The three components in lignocellulose biofibres, i.e. lignin, cellulose and hemicellulose, were differentiated, and theoretical BMP (TBMP) and material degradability (BMP from laboratory incubation tests divided by TBMP) were expressed. Moreover, the degradability of lignocellulose biofibres (the share of volatile lignocellulose biofibre solids degraded in laboratory incubation tests) was calculated. Finally, BMP for average SSOHW composition in Denmark (untreated) was calculated, and the BMP contribution of the individual material fractions was then evaluated. Material fractions of the two general waste types, defined as "food waste" and "fibre-rich waste," were found to be anaerobically degradable with considerable BMP. Material degradability of material fractions such as vegetation waste, moulded fibres, animal straw, dirty paper and dirty cardboard, however, was constrained by lignin content. BMP for overall SSOHW (untreated) was 404 mL CH4 per g VS, which might increase if the relative content of material fractions, such as animal and vegetable food waste, kitchen tissue and dirty paper in the waste, becomes larger. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characterising Super Earths With The EChO Spacemission Concept

NASA Astrophysics Data System (ADS)

Tessenyi, Marcell; Ollivier, M.; Tinetti, G.; Beaulieu, J. P.; Coudé du Foresto, V.; Encrenaz, T.; Micela, G.; Swinyard, B.; Ribas, I.; Aylward, A.; Tennyson, J.; Swain, M. R.; Sozzetti, A.; Vasisht, G.; Deroo, P.

2011-09-01

Transiting Super Earths orbiting M dwarfs are excellent targets for the prospect of studying potentially habitable extrasolar planets. While most of the currently known Exoplanets are of the Hot Jupiter and Neptune type, attention is now turning to these Super Earths. Two recent examples are GJ 1214b, found by Charbonneau et al. in 2009, and Cancri 55 e, found by Winn et al. in 2011. These candidates offer the opportunity of obtaining spectral signatures of their atmospheres in transiting scenarios, via data obtained by ground based and space observatories, compared to simulated climate scenarios. With the recent selection of the Exoplanet Characterisation Observatory (EChO) mission by ESA for further studies, I present observational strategies and time requirements for a range of targets characterisable by EChO, with a view to Super Earths orbiting M dwarfs.

[Study of quality of a branch laboratory--an opinion of a laboratory manager].

PubMed

Yazawa, Naoyuki

2006-11-01

At the stage of establishing a branch laboratory, quality evaluation is extremely difficult. Even the results of a control survey by the headquarters of the branch laboratory are unhelpful. For a clinical laboratory, the most important function is to provide reliable data all the time, and to maintain the reliability of clinical doctors with informed responses. We mostly refer to control surveys and daily quality control data to evaluate a clinical laboratory, but we rarely check its fundamental abilities, such as planning events, preserving statistical data about the standard range, using the right method for quality control and others. This is generally disregarded and it is taken for granted that they will be correct the first time. From my six years of experience working with X's branch laboratory, I realized that there might be some relation between the quality of a branch laboratory and the fundamental abilities of the company itself. I would never argue that all branch laboratories are ineffective, but they should be conscious of fundamental activities. The referring laboratory, not the referral laboratory, should be responsible for ensuring that the referral laboratory's examination results and findings are correct.

Errors in clinical laboratories or errors in laboratory medicine?

PubMed

Plebani, Mario

2006-01-01

Laboratory testing is a highly complex process and, although laboratory services are relatively safe, they are not as safe as they could or should be. Clinical laboratories have long focused their attention on quality control methods and quality assessment programs dealing with analytical aspects of testing. However, a growing body of evidence accumulated in recent decades demonstrates that quality in clinical laboratories cannot be assured by merely focusing on purely analytical aspects. The more recent surveys on errors in laboratory medicine conclude that in the delivery of laboratory testing, mistakes occur more frequently before (pre-analytical) and after (post-analytical) the test has been performed. Most errors are due to pre-analytical factors (46-68.2% of total errors), while a high error rate (18.5-47% of total errors) has also been found in the post-analytical phase. Errors due to analytical problems have been significantly reduced over time, but there is evidence that, particularly for immunoassays, interference may have a serious impact on patients. A description of the most frequent and risky pre-, intra- and post-analytical errors and advice on practical steps for measuring and reducing the risk of errors is therefore given in the present paper. Many mistakes in the Total Testing Process are called "laboratory errors", although these may be due to poor communication, action taken by others involved in the testing process (e.g., physicians, nurses and phlebotomists), or poorly designed processes, all of which are beyond the laboratory's control. Likewise, there is evidence that laboratory information is only partially utilized. A recent document from the International Organization for Standardization (ISO) recommends a new, broader definition of the term "laboratory error" and a classification of errors according to different criteria. In a modern approach to total quality, centered on patients' needs and satisfaction, the risk of errors and mistakes

Indomethacin nanocrystals prepared by different laboratory scale methods: effect on crystalline form and dissolution behavior

NASA Astrophysics Data System (ADS)

Martena, Valentina; Censi, Roberta; Hoti, Ela; Malaj, Ledjan; Di Martino, Piera

2012-12-01

The objective of this study is to select very simple and well-known laboratory scale methods able to reduce particle size of indomethacin until the nanometric scale. The effect on the crystalline form and the dissolution behavior of the different samples was deliberately evaluated in absence of any surfactants as stabilizers. Nanocrystals of indomethacin (native crystals are in the γ form) (IDM) were obtained by three laboratory scale methods: A (Batch A: crystallization by solvent evaporation in a nano-spray dryer), B (Batch B-15 and B-30: wet milling and lyophilization), and C (Batch C-20-N and C-40-N: Cryo-milling in the presence of liquid nitrogen). Nanocrystals obtained by the method A (Batch A) crystallized into a mixture of α and γ polymorphic forms. IDM obtained by the two other methods remained in the γ form and a different attitude to the crystallinity decrease were observed, with a more considerable decrease in crystalline degree for IDM milled for 40 min in the presence of liquid nitrogen. The intrinsic dissolution rate (IDR) revealed a higher dissolution rate for Batches A and C-40-N, due to the higher IDR of α form than γ form for the Batch A, and the lower crystallinity degree for both the Batches A and C-40-N. These factors, as well as the decrease in particle size, influenced the IDM dissolution rate from the particle samples. Modifications in the solid physical state that may occur using different particle size reduction treatments have to be taken into consideration during the scale up and industrial development of new solid dosage forms.

Spectral Characteristics of Continuous Acoustic Emission (AE) Data from Laboratory Rock Deformation Experiments

NASA Astrophysics Data System (ADS)

Flynn, J. William; Goodfellow, Sebastian; Reyes-Montes, Juan; Nasseri, Farzine; Young, R. Paul

2016-04-01

Continuous acoustic emission (AE) data recorded during rock deformation tests facilitates the monitoring of fracture initiation and propagation due to applied stress changes. Changes in the frequency and energy content of AE waveforms have been previously observed and were associated with microcrack coalescence and the induction or mobilisation of large fractures which are naturally associated with larger amplitude AE events and lower-frequency components. The shift from high to low dominant frequency components during the late stages of the deformation experiment, as the rate of AE events increases and the sample approaches failure, indicates a transition from the micro-cracking to macro-cracking regime, where large cracks generated result in material failure. The objective of this study is to extract information on the fracturing process from the acoustic records around sample failure, where the fast occurrence of AE events does not allow for identification of individual AE events and phase arrivals. Standard AE event processing techniques are not suitable for extracting this information at these stages. Instead the observed changes in the frequency content of the continuous record can be used to characterise and investigate the fracture process at the stage of microcrack coalescence and sample failure. To analyse and characterise these changes, a detailed non-linear and non-stationary time-frequency analysis of the continuous waveform data is required. Empirical Mode Decomposition (EMD) and Hilbert Spectral Analysis (HSA) are two of the techniques used in this paper to analyse the acoustic records which provide a high-resolution temporal frequency distribution of the data. In this paper we present the results from our analysis of continuous AE data recorded during a laboratory triaxial deformation experiment using the combined EMD and HSA method.

Thoracic organ transplantation: laboratory methods.

PubMed

Patel, Jignesh K; Kobashigawa, Jon A

2013-01-01

Although great progress has been achieved in thoracic organ transplantation through the development of effective immunosuppression, there is still significant risk of rejection during the early post-transplant period, creating a need for routine monitoring for both acute antibody and cellular mediated rejection. The currently available multiplexed, microbead assays utilizing solubilized HLA antigens afford the capability of sensitive detection and identification of HLA and non-HLA specific antibodies. These assays are being used to assess the relative strength of donor specific antibodies; to permit performance of virtual crossmatches which can reduce the waiting time to transplantation; to monitor antibody levels during desensitization; and for heart transplants to monitor antibodies post-transplant. For cell mediated immune responses, the recent development of gene expression profiling has allowed noninvasive monitoring of heart transplant recipients yielding predictive values for acute cellular rejection. T cell immune monitoring in heart and lung transplant recipients has allowed individual tailoring of immunosuppression, particularly to minimize risk of infection. While the current antibody and cellular laboratory techniques have enhanced the ability to manage thoracic organ transplant recipients, future developments from improved understanding of microchimerism and graft tolerance may allow more refined allograft monitoring techniques.

An Inexpensive, Relatively Green, and Rapid Method to Purify Genomic DNA from "Escherichia Coli": An Experiment for the Undergraduate Biochemistry Laboratory

ERIC Educational Resources Information Center

Sims, Paul A.; Branscum, Katie M.; Kao, Lydia; Keaveny, Virginia R.

2010-01-01

A method to purify genomic DNA from "Escherichia coli" is presented. The method is an amalgam of published methods but has been modified and optimized for use in the undergraduate biochemistry laboratory. Specifically, the method uses Tide Free 2x Ultra laundry detergent, which contains unspecified proteases and lipases, "n"-butanol, 2-propanol,…

Identification and characterisation of eight novel SERPINA1 Null mutations.

PubMed

Ferrarotti, Ilaria; Carroll, Tomás P; Ottaviani, Stefania; Fra, Anna M; O'Brien, Geraldine; Molloy, Kevin; Corda, Luciano; Medicina, Daniela; Curran, David R; McElvaney, Noel G; Luisetti, Maurizio

2014-11-26

Alpha-1 antitrypsin (AAT) is the most abundant circulating antiprotease and is a member of the serine protease inhibitor (SERPIN) superfamily. The gene encoding AAT is the highly polymorphic SERPINA1 gene, found at 14q32.1. Mutations in the SERPINA1 gene can lead to AAT deficiency (AATD) which is associated with a substantially increased risk of lung and liver disease. The most common pathogenic AAT variant is Z (Glu342Lys) which causes AAT to misfold and polymerise within hepatocytes and other AAT-producing cells. A group of rare mutations causing AATD, termed Null or Q0, are characterised by a complete absence of AAT in the plasma. While ultra rare, these mutations confer a particularly high risk of emphysema. We performed the determination of AAT serum levels by a rate immune nephelometric method or by immune turbidimetry. The phenotype was determined by isoelectric focusing analysis on agarose gel with specific immunological detection. DNA was isolated from whole peripheral blood or dried blood spot (DBS) samples using a commercial extraction kit. The new mutations were identified by sequencing all coding exons (II-V) of the SERPINA1 gene. We have found eight previously unidentified SERPINA1 Null mutations, named: Q0cork, Q0perugia, Q0brescia, Q0torino, Q0cosenza, Q0pordenone, Q0lampedusa, and Q0dublin . Analysis of clinical characteristics revealed evidence of the recurrence of lung symptoms (dyspnoea, cough) and lung diseases (emphysema, asthma, chronic bronchitis) in M/Null subjects, over 45 years-old, irrespective of smoking. We have added eight more mutations to the list of SERPINA1 Null alleles. This study underlines that the laboratory diagnosis of AATD is not just a matter of degree, because the precise determination of the deficiency and Null alleles carried by an AATD individual may help to evaluate the risk for the lung disease.

Development of a Methodology for the Characterisation of Air-coupled Ultrasound Probes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pietroni, Paolo; Marco Revel, Gian

2010-05-28

This study is aimed at developing a technique for the characterisation of air-coupled ultrasound probes, starting from the analysis of the mechanical behaviour of the probe membrane. The vibratory behaviour of the emission membrane is studied using laser-Doppler vibrometry techniques with high frequency demodulation system (20 MHz). The determination of the vibration provides information which are useful for the assessment of the performance of the probe, in particular concerning the Quality factor and the portion of the membrane which really contributes to the emission. During the second step the results of the vibration measurements are used to calculate, by meansmore » of numerical boundary element method, the ultrasound beam emitted in terms of intensity in space. The obtained field is compared with the direct measurements carried out by scanning with the receiver probe and a pinhole plate. This comparison allows the potential and the problems of the two different characterisation techniques to be determined, even if the pinhole technique (which is currently considered the state of the art) cannot be used as an absolute reference. This study appears to be useful for paving the way for a new methodology for the calibration of air-coupled ultrasound probes, which potentially could be used not only to improve the probe manufacturing process, but also to control conformity to specifications.« less

Development of a Methodology for the Characterisation of Air-coupled Ultrasound Probes

NASA Astrophysics Data System (ADS)

Pietroni, Paolo; Marco Revel, Gian

2010-05-01

This study is aimed at developing a technique for the characterisation of air-coupled ultrasound probes, starting from the analysis of the mechanical behaviour of the probe membrane. The vibratory behaviour of the emission membrane is studied using laser-Doppler vibrometry techniques with high frequency demodulation system (20 MHz). The determination of the vibration provides information which are useful for the assessment of the performance of the probe, in particular concerning the Quality factor and the portion of the membrane which really contributes to the emission. During the second step the results of the vibration measurements are used to calculate, by means of numerical boundary element method, the ultrasound beam emitted in terms of intensity in space. The obtained field is compared with the direct measurements carried out by scanning with the receiver probe and a pinhole plate. This comparison allows the potential and the problems of the two different characterisation techniques to be determined, even if the pinhole technique (which is currently considered the state of the art) cannot be used as an absolute reference. This study appears to be useful for paving the way for a new methodology for the calibration of air-coupled ultrasound probes, which potentially could be used not only to improve the probe manufacturing process, but also to control conformity to specifications.

Solutions for characterising natural landscapes in New Zealand using geographical information systems.

PubMed

Brabyn, Lars

2005-07-01

This paper explores solutions for characterising naturalness in relation to visual landscapes using Geographical Information System (GIS). It is argued that planners need to identify natural landscapes and monitor changes in their extent. Just like the indices that have been developed to describe the state of the economy, indices need to be developed that monitor the state of natural landscapes. The complications in characterising natural landscapes are outlined but it is argued that there is a need to develop definitions of natural landscapes that can be operationalised with a GIS. This will have the advantages of the efficiency of the technology and that the definition will be explicit and the implementation will be independent of the operator. Several GIS solutions are provided and these are an analysis of landcover, a density analysis of roads and utilities, and an analysis of property sizes. The analysis of property sizes is sensitive to many human modifications of the landscape because many developments begin with the subdivision of properties. However, it is argued in this paper that no one definition will suffice and that all three methods provide different, yet important, insights into natural landscape character. An aggregate classification of naturalness based on the majority value of the indices is demonstrated as well as a range of techniques for expressing the uncertainty of the aggregate classification.

MICROBIAL LABORATORY GUIDANCE MANUAL FOR THE ...

EPA Pesticide Factsheets

The Long-Term 2 Enhanced Surface Water Treatment Rule Laboratory Instruction Manual will be a compilation of all information needed by laboratories and field personnel to collect, analyze, and report the microbiological data required under the rule. The manual will provide laboratories with a single source of information that currently is available from various sources including the latest versions of Methods 1622 and 1623, including all approved, equivalent modifications; the procedures for E.coli methods approved for use under the LT2ESWTR; lists of vendor sources; data recording forms; data reporting requirements; information on the Laboratory Quality Assurance Evaluation Program for the Analysis of Cryptosporidium in Water; and sample collection procedures. Although most of this information is available elsewhere, a single, comprehensive compendium containing this information is needed to aid utilities and laboratories performing the sampling and analysis activities required under the LT2 rule. This manual will serve as an instruction manual for laboratories to use when collecting data for Crypto, E. coli and turbidity.

Manufacturing Laboratory | Energy Systems Integration Facility | NREL

Science.gov Websites

Manufacturing Laboratory Manufacturing Laboratory Researchers in the Energy Systems Integration Facility's Manufacturing Laboratory develop methods and technologies to scale up renewable energy technology manufacturing capabilities. Photo of researchers and equipment in the Manufacturing Laboratory. Capability Hubs

Characterisation of a new, highly effective method for detecting nematode eggs (Ascaris spp., Toxocara spp., Trichuris spp.) in sewage sludge containing flocculants.

PubMed

Zdybel, Jolanta; Karamon, Jacek; Różycki, Mirosław; Bilska-Zając, Ewa; Kłapeć, Teresa; Cencek, Tomasz

2016-11-01

Because traditional methods used for sewage sludge parasitological examinations have low sensitivity, a new, highly effective method (own method - OM) was devised. The principle of this method is to eliminate the flocculent effect on the structure of sewage sludge by mechanically damaging floccules in the presence of surfactants and to increase the effectiveness of egg isolation processes in large volumes of liquids. The objective of this study was to estimate the effectiveness of the OM in detecting nematode eggs in sewage sludge samples containing flocculants. In the first stage, the effectiveness of the OM was compared to 4 other methods routinely used in parasitological examinations of dehydrated sewage sludge. Next, method standardisation was performed using sewage sludge samples supplemented with eggs from 3 parasite species (Ascaris suum, Toxocara canis and Trichuris vulpis). The study demonstrated that OM efficiency was 6-65 times greater than other methods, depending on the method and type of detected eggs. Limit of detection (LOD) calculations for the OM were performed on samples supplemented with a known number of parasite eggs resulting in 10, 5 and 3 eggs/50 g of sample for A. suum, T. vulpis and T. canis eggs, respectively. The limits of quantification (LOQ) of the OM were established as 200 eggs/50 g of sample for A. suum and T. vulpis eggs and 50 eggs/50 g of sample for T. canis eggs. The rectilinear regression functions, which determined the relationship between the number of eggs detected in OM measurements and the number of eggs contained in the samples, were characterised by high and statistically significant coefficients of determination (r 2 ). The slopes of the trend lines were 0.3188, 0.3821 and 0.3276, and the intercepts were -11.223, -9.0261 and -23.15 for A. suum, T. canis and T. vulpis eggs, respectively. Method sensitivity, calculated as the slope coefficient of the regression function and expressed as a percentage, ranged

New reporting procedures based on long-term method detection levels and some considerations for interpretations of water-quality data provided by the U.S. Geological Survey National Water Quality Laboratory

USGS Publications Warehouse

Childress, Carolyn J. Oblinger; Foreman, William T.; Connor, Brooke F.; Maloney, Thomas J.

1999-01-01

This report describes the U.S. Geological Survey National Water Quality Laboratory?s approach for determining long-term method detection levels and establishing reporting levels, details relevant new reporting conventions, and provides preliminary guidance on interpreting data reported with the new conventions. At the long-term method detection level concentration, the risk of a false positive detection (analyte reported present at the long-term method detection level when not in sample) is no more than 1 percent. However, at the long-term method detection level, the risk of a false negative occurrence (analyte reported not present when present at the long-term method detection level concentration) is up to 50 percent. Because this false negative rate is too high for use as a default 'less than' reporting level, a more reliable laboratory reporting level is set at twice the determined long-term method detection level. For all methods, concentrations measured between the laboratory reporting level and the long-term method detection level will be reported as estimated concentrations. Non-detections will be censored to the laboratory reporting level. Adoption of the new reporting conventions requires a full understanding of how low-concentration data can be used and interpreted and places responsibility for using and presenting final data with the user rather than with the laboratory. Users must consider that (1) new laboratory reporting levels may differ from previously established minimum reporting levels, (2) long-term method detection levels and laboratory reporting levels may change over time, and (3) estimated concentrations are less certain than concentrations reported above the laboratory reporting level. The availability of uncensored but qualified low-concentration data for interpretation and statistical analysis is a substantial benefit to the user. A decision to censor data after they are reported from the laboratory may still be made by the user, if

[Laboratory diagnosis of toxoplasmosis].

PubMed

Strhársky, J; Mad'arová, L; Klement, C

2009-04-01

Under Central European climatic conditions, toxoplasmosis is one of the most common human parasitic diseases. A wide range of methods for both direct and indirect detection of the causative agent are currently available for the laboratory diagnosis of toxoplasmosis. The purpose of the article is to review the history of the discovery of the causative agent of toxoplasmosis and how laboratory diagnostic methods were developed and improved. The main emphasis is placed on current options in the diagnosis of Toxoplasma gondii, more precisely on the serodiagnosis and new trends in molecular biology-based techniques.

Combining Nordtest method and bootstrap resampling for measurement uncertainty estimation of hematology analytes in a medical laboratory.

PubMed

Cui, Ming; Xu, Lili; Wang, Huimin; Ju, Shaoqing; Xu, Shuizhu; Jing, Rongrong

2017-12-01

Measurement uncertainty (MU) is a metrological concept, which can be used for objectively estimating the quality of test results in medical laboratories. The Nordtest guide recommends an approach that uses both internal quality control (IQC) and external quality assessment (EQA) data to evaluate the MU. Bootstrap resampling is employed to simulate the unknown distribution based on the mathematical statistics method using an existing small sample of data, where the aim is to transform the small sample into a large sample. However, there have been no reports of the utilization of this method in medical laboratories. Thus, this study applied the Nordtest guide approach based on bootstrap resampling for estimating the MU. We estimated the MU for the white blood cell (WBC) count, red blood cell (RBC) count, hemoglobin (Hb), and platelets (Plt). First, we used 6months of IQC data and 12months of EQA data to calculate the MU according to the Nordtest method. Second, we combined the Nordtest method and bootstrap resampling with the quality control data and calculated the MU using MATLAB software. We then compared the MU results obtained using the two approaches. The expanded uncertainty results determined for WBC, RBC, Hb, and Plt using the bootstrap resampling method were 4.39%, 2.43%, 3.04%, and 5.92%, respectively, and 4.38%, 2.42%, 3.02%, and 6.00% with the existing quality control data (U [k=2]). For WBC, RBC, Hb, and Plt, the differences between the results obtained using the two methods were lower than 1.33%. The expanded uncertainty values were all less than the target uncertainties. The bootstrap resampling method allows the statistical analysis of the MU. Combining the Nordtest method and bootstrap resampling is considered a suitable alternative method for estimating the MU. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

An interlaboratory comparison of nanosilver characterisation and hazard identification: Harmonising techniques for high quality data.

PubMed

Jemec, Anita; Kahru, Anne; Potthoff, Annegret; Drobne, Damjana; Heinlaan, Margit; Böhme, Steffi; Geppert, Mark; Novak, Sara; Schirmer, Kristin; Rekulapally, Rohit; Singh, Shashi; Aruoja, Villem; Sihtmäe, Mariliis; Juganson, Katre; Käkinen, Aleksandr; Kühnel, Dana

2016-02-01

Within the FP7 EU project NanoValid a consortium of six partners jointly investigated the hazard of silver nanoparticles (AgNPs) paying special attention to methodical aspects that are important for providing high-quality ecotoxicity data. Laboratories were supplied with the same original stock dispersion of AgNPs. All partners applied a harmonised procedure for storage and preparation of toxicity test suspensions. Altogether ten different toxicity assays with a range of environmentally relevant test species from different trophic levels were conducted in parallel to AgNP characterisation in the respective test media. The paper presents a comprehensive dataset of toxicity values and AgNP characteristics like hydrodynamic sizes of AgNP agglomerates and the share (%) of Ag(+)-species (the concentration of Ag(+)-species in relation to the total measured concentration of Ag). The studied AgNP preparation (20.4±6.8 nm primary size, mean total Ag concentration 41.14 mg/L, 46-68% of soluble Ag(+)-species in stock, 123.8±12.2 nm mean z-average value in dH2O) showed extreme toxicity to crustaceans Daphnia magna, algae Pseudokirchneriella subcapitata and zebrafish Danio rerio embryos (EC50<0.01 mg total Ag/L), was very toxic in the in vitro assay with rainbow trout Oncorhynchus mykiss gut cells (EC50: 0.01-1 mg total Ag/L); toxic to bacteria Vibrio fischeri, protozoa Tetrahymena thermophila (EC50: 1-10 mg total Ag/L) and harmful to marine crustaceans Artemia franciscana (EC50: 10-100 mg total Ag/L). Along with AgNPs, also the toxicity of AgNO3 was analyzed. The toxicity data revealed the same hazard ranking for AgNPs and AgNO3 (i.e. the EC50 values were in the same order of magnitude) proving the importance of soluble Ag(+)-species analysis for predicting the hazard of AgNPs. The study clearly points to the need for harmonised procedures for the characterisation of NMs. Harmonised procedures should consider: (i) measuring the AgNP properties like hydrodynamic size and

Rabies in Iraq: trends in human cases 2001-2010 and characterisation of animal rabies strains from Baghdad.

PubMed

Horton, Daniel L; Ismail, Mashair Z; Siryan, Eman S; Wali, Abdul Raheem A; Ab-dulla, Husam E; Wise, Emma; Voller, Katja; Harkess, Graeme; Marston, Denise A; McElhinney, Lorraine M; Abbas, Salah F; Fooks, Anthony R

2013-01-01

Control of rabies requires a consistent supply of dependable resources, constructive cooperation between veterinary and public health authorities, and systematic surveillance. These are challenging in any circumstances, but particularly during conflict. Here we describe available human rabies surveillance data from Iraq, results of renewed sampling for rabies in animals, and the first genetic characterisation of circulating rabies strains from Iraq. Human rabies is notifiable, with reported cases increasing since 2003, and a marked increase in Baghdad between 2009 and 2010. These changes coincide with increasing numbers of reported dog bites. There is no laboratory confirmation of disease or virus characterisation and no systematic surveillance for rabies in animals. To address these issues, brain samples were collected from domestic animals in the greater Baghdad region and tested for rabies. Three of 40 brain samples were positive using the fluorescent antibody test and hemi-nested RT-PCR for rabies virus (RABV). Bayesian phylogenetic analysis using partial nucleoprotein gene sequences derived from the samples demonstrated the viruses belong to a single virus variant and share a common ancestor with viruses from neighbouring countries, 22 (95% HPD 14-32) years ago. These include countries lying to the west, north and east of Iraq, some of which also have other virus variants circulating concurrently. These results suggest possible multiple introductions of rabies into the Middle East, and regular trans-boundary movement of disease. Although 4000 years have passed since the original description of disease consistent with rabies, animals and humans are still dying of this preventable and neglected zoonosis.

Fabrication, characterisation and voltammetric studies of gold amalgam nanoparticle modified electrodes.

PubMed

Welch, Christine M; Nekrassova, Olga; Dai, Xuan; Hyde, Michael E; Compton, Richard G

2004-09-20

The tabrication, characterisation, and electroanalytical application of gold and gold amalgam nanoparticles on glassy carbon electrodes is examined. Once the deposition parameters for gold nanoparticle electrodes were optimised, the analytical utility of the electrodes was examined in CrIII electroanalysis. It was found that gold nanoparticle modified (Au-NM) electrodes possess higher sensitivity than gold macroelectrodes. In addition, gold amalgam nanoparticle modified (AuHg-NM) electrodes were fabricated and characterised. The response of those electrodes was recorded in the presence of important environmental analytes (heavy metal cations). It was found AuHg-NM electrodes demonstrate a unique voltammetric behaviour and can be applied for electroanalysis when enhanced sensitivity is crucial.

[The reproductive correlates of social hierarchy in laboratory male mice].

PubMed

Osadchuk, L B; Salomacheva, I N; Bragin, A V; Osadchuk, A V

2007-01-01

In laboratory male mice the effects of social hierarchy on hormonal and spermatogenic testicular function, accessory organs and testicular weights, sexual behaviour have been investigated using an experimental model of social hierarchy, which is characterised by a minimal size (two male mice) and 5 days period of social interactions. The social rank of the partners was detected by asymmetry in aggressive behaviour. Using the experimental condition, when the both partners have no preferences for exclusive use of area we demonstrated that there were no rank differences in the number of mounts and testicular testosterone content. Nevertheless a rank asymmetry in the male sniffing behaviour towards a receptive female, weights of the testes, seminal vesicles, epididymes and the number of epididymal sperm was kept up in a stable social group. Social dominance was found to affect negatively on testicular testosterone increase in response to introduction of a receptive female and sexual attractiveness of male to a receptive female in both dominant and subordinate males. The results obtained demonstrate the impact of social hierarchy on reproduction in laboratory male mice, particular in respect of spermatogenesis and the testicular testosterone in response to a receptive female.

a Study of Radial Vibrations of a Rolling Tyre for TYRE-ROAD Noise Characterisation

NASA Astrophysics Data System (ADS)

Périsse, J.

2002-11-01

Because tyre-road noise represents the main noise source for light vehicles with driving speed above 60 km/h, comprehension of generation mechanism of tyre-road noise has become a subject of major importance. In this paper, tyre-road interaction and radial tyre vibrations are investigated for tyre-road noise characterisation. Experimental measurements are performed on a rolling smooth tyre with test laboratory facilities. Both tread band and sidewall responses of the tyre are measured and compared to each other. High concentration of vibrations is observed in the vicinity of the contact area. Stationary radial deformation and non-stationary vibrations due to road rugosity are studied. Frequency analyses have been performed on the acceleration time signals showing the influence of the rotating speed on the vibrations level and frequency content. Finally, by integrating acceleration signal of the tyre tread over one revolution, stationary radial displacement can be calculated and the true contact length can be estimated. This study provides us with new measurement data for comparison with mathematical modelling. It also gives a physical insight on generation mechanism of tyre radial vibrations.

An anthropometric approach to characterising neonatal morbidity and body composition, using air displacement plethysmography as a criterion method

PubMed Central

Carberry, Angela E.; Turner, Robin M.; Bek, Emily J.; Raynes-Greenow, Camille H.; McEwan, Alistair L.; Jeffery, Heather E.

2018-01-01

Background With the greatest burden of infant undernutrition and morbidity in low and middle income countries (LMICs), there is a need for suitable approaches to monitor infants in a simple, low-cost and effective manner. Anthropometry continues to play a major role in characterising growth and nutritional status. Methods We developed a range of models to aid in identifying neonates at risk of malnutrition. We first adopted a logistic regression approach to screen for a composite neonatal morbidity, low and high body fat (BF%) infants. We then developed linear regression models for the estimation of neonatal fat mass as an assessment of body composition and nutritional status. Results We fitted logistic regression models combining up to four anthropometric variables to predict composite morbidity and low and high BF% neonates. The greatest area under receiver-operator characteristic curves (AUC with 95% confidence intervals (CI)) for identifying composite morbidity was 0.740 (0.63, 0.85), resulting from the combination of birthweight, length, chest and mid-thigh circumferences. The AUCs (95% CI) for identifying low and high BF% were 0.827 (0.78, 0.88) and 0.834 (0.79, 0.88), respectively. For identifying composite morbidity, BF% as measured via air displacement plethysmography showed strong predictive ability (AUC 0.786 (0.70, 0.88)), while birthweight percentiles had a lower AUC (0.695 (0.57, 0.82)). Birthweight percentiles could also identify low and high BF% neonates with AUCs of 0.792 (0.74, 0.85) and 0.834 (0.79, 0.88). We applied a sex-specific approach to anthropometric estimation of neonatal fat mass, demonstrating the influence of the testing sample size on the final model performance. Conclusions These models display potential for further development and evaluation in LMICs to detect infants in need of further nutritional management, especially where traditional methods of risk management such as birthweight for gestational age percentiles may be variable

Characterising encapsulated nuclear waste using cosmic-ray muon tomography

NASA Astrophysics Data System (ADS)

Clarkson, A.; Hamilton, D. J.; Hoek, M.; Ireland, D. G.; Johnstone, J. R.; Kaiser, R.; Keri, T.; Lumsden, S.; Mahon, D. F.; McKinnon, B.; Murray, M.; Nutbeam-Tuffs, S.; Shearer, C.; Yang, G.; Zimmerman, C.

2015-03-01

Tomographic imaging techniques using the Coulomb scattering of cosmic-ray muons have been shown previously to successfully identify and characterise low- and high-Z materials within an air matrix using a prototype scintillating-fibre tracker system. Those studies were performed as the first in a series to assess the feasibility of this technology and image reconstruction techniques in characterising the potential high-Z contents of legacy nuclear waste containers for the U.K. Nuclear Industry. The present work continues the feasibility study and presents the first images reconstructed from experimental data collected using this small-scale prototype system of low- and high-Z materials encapsulated within a concrete-filled stainless-steel container. Clear discrimination is observed between the thick steel casing, the concrete matrix and the sample materials assayed. These reconstructed objects are presented and discussed in detail alongside the implications for future industrial scenarios.

7 CFR 160.17 - Laboratory analysis.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 3 2011-01-01 2011-01-01 false Laboratory analysis. 160.17 Section 160.17 Agriculture... STANDARDS FOR NAVAL STORES Methods of Analysis, Inspection, Sampling and Grading § 160.17 Laboratory analysis. The analysis and laboratory testing of naval stores shall be conducted, so far as is practicable...

7 CFR 160.17 - Laboratory analysis.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Laboratory analysis. 160.17 Section 160.17 Agriculture... STANDARDS FOR NAVAL STORES Methods of Analysis, Inspection, Sampling and Grading § 160.17 Laboratory analysis. The analysis and laboratory testing of naval stores shall be conducted, so far as is practicable...

Suitability of the echo-time-shift method as laboratory standard for thermal ultrasound dosimetry

NASA Astrophysics Data System (ADS)

Fuhrmann, Tina; Georg, Olga; Haller, Julian; Jenderka, Klaus-Vitold

2017-03-01

Ultrasound therapy is a promising, non-invasive application with potential to significantly improve cancer therapies like surgery, viro- or immunotherapy. This therapy needs faster, cheaper and more easy-to-handle quality assurance tools for therapy devices as well as possibilities to verify treatment plans and for dosimetry. This limits comparability and safety of treatments. Accurate spatial and temporal temperature maps could be used to overcome these shortcomings. In this contribution first results of suitability and accuracy investigations of the echo-time-shift method for two-dimensional temperature mapping during and after sonication are presented. The analysis methods used to calculate time-shifts were a discrete frame-to-frame and a discrete frame-to-base-frame algorithm as well as a sigmoid fit for temperature calculation. In the future accuracy could be significantly enhanced by using continuous methods for time-shift calculation. Further improvements can be achieved by improving filtering algorithms and interpolation of sampled diagnostic ultrasound data. It might be a comparatively accurate, fast and affordable method for laboratory and clinical quality control.

Characterisation of a novel reverse-biased PPD CMOS image sensor

NASA Astrophysics Data System (ADS)

Stefanov, K. D.; Clarke, A. S.; Ivory, J.; Holland, A. D.

2017-11-01

A new pinned photodiode (PPD) CMOS image sensor (CIS) has been developed and characterised. The sensor can be fully depleted by means of reverse bias applied to the substrate, and the principle of operation is applicable to very thick sensitive volumes. Additional n-type implants under the pixel p-wells, called Deep Depletion Extension (DDE), have been added in order to eliminate the large parasitic substrate current that would otherwise be present in a normal device. The first prototype has been manufactured on a 18 μm thick, 1000 Ω .cm epitaxial silicon wafers using 180 nm PPD image sensor process at TowerJazz Semiconductor. The chip contains arrays of 10 μm and 5.4 μm pixels, with variations of the shape, size and the depth of the DDE implant. Back-side illuminated (BSI) devices were manufactured in collaboration with Teledyne e2v, and characterised together with the front-side illuminated (FSI) variants. The presented results show that the devices could be reverse-biased without parasitic leakage currents, in good agreement with simulations. The new 10 μm pixels in both BSI and FSI variants exhibit nearly identical photo response to the reference non-modified pixels, as characterised with the photon transfer curve. Different techniques were used to measure the depletion depth in FSI and BSI chips, and the results are consistent with the expected full depletion.

Rapid characterisation and identification of compounds in Saposhnikoviae Radix by high-performance liquid chromatography coupled with electrospray ionisation quadrupole time-of-flight mass spectrometry.

PubMed

Chen, Luxiao; Chen, Xiangyang; Su, Lei; Jiang, Yanyan; Liu, Bin

2018-04-01

Saposhnikoviae Radix (SR), the dried root of Saposhnikovia divaricata (Turcz.) Schischk. (Umbelliferae), is commonly used as a traditional Chinese medicine. In this study, a rapid and accurate method was firstly, developed for the qualitative analysis of SR by high-performance liquid chromatography coupled with electrospray ionisation quadrupole time-of-flight mass spectrometry (HPLC-ESI-Q-TOF-MS/MS). A total of 45 compounds were identified or tentatively characterised, including 13 chromones, 28 coumarins and four others. Among them, 16 compounds were identified from SR for the first time. In addition, six chromones reference standards, including two isolated compounds of 3'-O-angeloylhamaudol and norcimifugin from the extraction of SR, were used to study the fragmentation pathways of chromones. The developed method was effective for characterising the compounds of SR, and the results of the study enriched the understanding of the chemical connotation.

Case Studies in Sustainability Used in an Introductory Laboratory Course to Enhance Laboratory Instruction

ERIC Educational Resources Information Center

Luster-Teasley, Stephanie; Hargrove-Leak, Sirena; Gibson, Willietta; Leak, Roland

2017-01-01

This educational research seeks to develop novel laboratory modules by using Case Studies in the Science Teaching method to introduce sustainability and environmental engineering laboratory concepts to 21st century learners. The increased interest in "going green" has led to a surge in the number of engineering students studying…

Characterisation of a natural quartz crystal as a reference material for microanalytical determination of Ti, Al, Li, Fe, Mn, Ga and Ge

USGS Publications Warehouse

Audetat, Andreas; Garbe-Schonberg, Dieter; Kronz, Andreas; Pettke, Thomas; Rusk, Brian G.; Donovan, John J.; Lowers, Heather

2015-01-01

A natural smoky quartz crystal from Shandong province, China, was characterised by laser ablation ICP-MS, electron probe microanalysis (EPMA) and solution ICP-MS to determine the concentration of twenty-four trace and ultra trace elements. Our main focus was on Ti quantification because of the increased use of this element for titanium-in-quartz (TitaniQ) thermobarometry. Pieces of a uniform growth zone of 9 mm thickness within the quartz crystal were analysed in four different LA-ICP-MS laboratories, three EPMA laboratories and one solution-ICP-MS laboratory. The results reveal reproducible concentrations of Ti (57 ± 4 μg g-1), Al (154 ± 15 μg g-1), Li (30 ± 2 μg g-1), Fe (2.2 ± 0.3 μg g-1), Mn (0.34 ± 0.04 μg g-1), Ge (1.7 ± 0.2 μg g-1) and Ga (0.020 ± 0.002 μg g-1) and detectable, but less reproducible, concentrations of Be, B, Na, Cu, Zr, Sn and Pb. Concentrations of K, Ca, Sr, Mo, Ag, Sb, Ba and Au were below the limits of detection of all three techniques. The uncertainties on the average concentration determinations by multiple techniques and laboratories for Ti, Al, Li, Fe, Mn, Ga and Ge are low; hence, this quartz can serve as a reference material or a secondary reference material for microanalytical applications involving the quantification of trace elements in quartz.

Laboratory Detection and Analysis of Organic Compounds in Rocks Using HPLC and XRD Methods

NASA Technical Reports Server (NTRS)

Dragoi, D.; Kanik, I.; Bar-Cohen, Y.; Sherrit, S.; Tsapin, A.; Kulleck, J.

2004-01-01

In this work we describe an analytical method for determining the presence of organic compounds in rocks, limestone, and other composite materials. Our preliminary laboratory experiments on different rocks/limestone show that the organic component in mineralogical matrices is a minor phase on order of hundreds of ppm and can be better detected using high precision liquid chromatography (HPLC). The matrix, which is the major phase, plays an important role in embedding and protecting the organic molecules from the harsh Martian environment. Some rocks bear significant amounts of amino acids therefore, it is possible to identify these phases using powder x-ray diffraction (XRD) by crystallizing the organic. The method of detection/analysis of organics, in particular amino acids, that have been associated with life will be shown in the next section.

Characterisation of Balance Capacity in Prader-Willi Patients

ERIC Educational Resources Information Center

Capodaglio, Paolo; Menegoni, Francesco; Vismara, Luca; Cimolin, Veronica; Grugni, Graziano; Galli, Manuela

2011-01-01

Being severely overweight is a distinctive clinical feature of Prader-Willi Syndrome (PWS). This explorative study aims to characterise balance capacity in PWS as compared to non-genetically obese patients (O) and to a group of normal-weight individuals (CG). We enrolled 14 PWS patients: 8 females and 6 males (BMI = 41.3 [plus or minus] 7.3…

Quantifying Human Response: Linking metrological and psychometric characterisations of Man as a Measurement Instrument

NASA Astrophysics Data System (ADS)

Pendrill, L. R.; Fisher, William P., Jr.

2013-09-01

A better understanding of how to characterise human response is essential to improved person-centred care and other situations where human factors are crucial. Challenges to introducing classical metrological concepts such as measurement uncertainty and traceability when characterising Man as a Measurement Instrument include the failure of many statistical tools when applied to ordinal measurement scales and a lack of metrological references in, for instance, healthcare. The present work attempts to link metrological and psychometric (Rasch) characterisation of Man as a Measurement Instrument in a study of elementary tasks, such as counting dots, where one knows independently the expected value because the measurement object (collection of dots) is prepared in advance. The analysis is compared and contrasted with recent approaches to this problem by others, for instance using signal error fidelity.

Agreement between clinical and laboratory methods assessing tonic and cross-link components of accommodation and vergence.

PubMed

Neveu, Pascaline; Priot, Anne-Emmanuelle; Philippe, Matthieu; Fuchs, Philippe; Roumes, Corinne

2015-09-01

Several tests are available to optometrists for investigating accommodation and vergence. This study sought to investigate the agreement between clinical and laboratory methods and to clarify which components are actually measured when tonic and cross-link of accommodation and vergence are assessed. Tonic vergence, tonic accommodation, accommodative vergence (AC/A) and vergence accommodation (CA/C) were measured using several tests. Clinical tests were compared to the laboratory assessment, the latter being regarded as an absolute reference. The repeatability of each test and the degree of agreement between the tests were quantified using Bland-Altman analysis. The values obtained for each test were found to be stable across repetitions; however, in most cases, significant differences were observed between tests supposed to measure the same oculomotor component. Tonic and cross-link components cannot be easily assessed because proximal and instrumental responses interfere with the assessment. Other components interfere with oculomotor assessment. Specifically, accommodative divergence interferes with tonic vergence estimation and the type of accommodation considered in the AC/A ratio affects its magnitude. Results on clinical tonic accommodation and clinical CA/C show that further investigation is needed to clarify the limitations associated with the use of difference of Gaussian as visual targets to open the accommodative loop. Although different optometric tests of accommodation and vergence rely on the same basic principles, the results of this study indicate that clinical and laboratory methods actually involve distinct components. These differences, which are induced by methodological choices, must be taken into account, when comparing studies or when selecting a test to investigate a particular oculomotor component. © 2015 The Authors. Clinical and Experimental Optometry © 2015 Optometry Australia.

Highlights from the SoilCAM project: Soil Contamination, Advanced integrated characterisation and time-lapse Monitoring

NASA Astrophysics Data System (ADS)

French, H. K.; van der Zee, S. E. A. T. M.; Wehrer, M.; Godio, A.; Pedersen, L. B.; Toscano, G.

2012-04-01

The SoilCAM project (Soil Contamination, Advanced integrated characterisation and time-lapse Monitoring 2008-2012, EU-FP7-212663) is aimed at improving current methods for monitoring contaminant distribution and biodegradation in the subsurface. At two test sites, Oslo airport Gardermoen in Norway and the Trecate site in Italy, a number of geophysical techniques, lysimeter and other soil and water sampling techniques as well as numerical flow and transport modelling have been combined at different scales in order to characterise flow transport processes in the unsaturated and saturated zones. Laboratory experiments have provided data on physical and bio-geo-chemical parameters for use in models and to select remediation methods. The geophysical techniques were used to map geological heterogeneities and also conduct time-lapse measurements of processes in the unsaturated zone. Both cross borehole and surface electrodes were used for electrical resistivity and induced polarisation surveys. The geophysical surveys showed clear indications of areas highly affected by de-icing chemicals along the runway at Oslo airport. The time lapse measurements along the runway at the airport show infiltration patterns during snowmelt and are used to validate 2D unsaturated flow and transport simulations using SUTRA. The Orchestra model is used to describe the complex interaction between bio-geo-chemical processes in a 1D profile along the runway. The presence of installations such as a membrane along the runway highly affects the flow pattern and challenges the capacity of the numerical code. Smaller scale field site measurements have revealed the increase of iron and manganese during degradation of de-icing chemicals. The use of Nitrate to increase red-ox potential was tested, but results have not been analysed yet. So far it cannot be concluded that degradation process can be quantified indirectly by geophysical monitoring. At the Trecate site a combination of georadar, electrical

Isolation and characterisation of cancer stem cells from canine osteosarcoma.

PubMed

Wilson, H; Huelsmeyer, M; Chun, R; Young, K M; Friedrichs, K; Argyle, D J

2008-01-01

There is increasing evidence that cancer is a stem cell disease. This study sought to isolate and characterise cancer stem cells from canine osteosarcoma. One human and three canine cell lines were cultured in non-adherent culture conditions using serum-starved, semi-solid media. Primitive sarcosphere colonies from all cell lines were identified under these conditions and were characterised using molecular and cytochemical techniques for embryonic stem cell markers. Expression of the embryonic stem cell-associated genes Nanog, Oct4 and STAT3 indicated a primitive phenotype. Sarcospheres could be reproduced consistently when passaged multiple times and produced adherent cell cultures when returned to normal growth conditions. Similarities between human and canine osteosarcoma cell lines add credence to the potential of the dog as a model for human disease.

Laboratory-associated infections and biosafety.

PubMed Central

Sewell, D L

1995-01-01

An estimated 500,000 laboratory workers in the United States are at risk of exposure to infectious agents that cause disease ranging from inapparent to life-threatening infections, but the precise risk to a given worker unknown. The emergence of human immunodeficiency virus and hantavirus, the continuing problem of hepatitis B virus, and the reemergence of Mycobacterium tuberculosis have renewed interest in biosafety for the employees of laboratories and health care facilities. This review examines the history, the causes, and the methods for prevention of laboratory-associated infections. The initial step in a biosafety program is the assessment of risk to the employee. Risk assessment guidelines include the pathogenicity of the infectious agent, the method of transmission, worker-related risk factors, the source and route of infection, and the design of the laboratory facility. Strategies for the prevention and management of laboratory-associated infections are based on the containment of the infectious agent by physical separation from the laboratory worker and the environment, employee education about the occupational risks, and availability of an employee health program. Adherence to the biosafety guidelines mandated or proposed by various governmental and accrediting agencies reduces the risk of an occupational exposure to infectious agents handled in the workplace. PMID:7553572

Characterisation of exposure to non-ionising electromagnetic fields in the Spanish INMA birth cohort: study protocol.

PubMed

Gallastegi, Mara; Guxens, Mònica; Jiménez-Zabala, Ana; Calvente, Irene; Fernández, Marta; Birks, Laura; Struchen, Benjamin; Vrijheid, Martine; Estarlich, Marisa; Fernández, Mariana F; Torrent, Maties; Ballester, Ferrán; Aurrekoetxea, Juan J; Ibarluzea, Jesús; Guerra, David; González, Julián; Röösli, Martin; Santa-Marina, Loreto

2016-02-18

Analysis of the association between exposure to electromagnetic fields of non-ionising radiation (EMF-NIR) and health in children and adolescents is hindered by the limited availability of data, mainly due to the difficulties on the exposure assessment. This study protocol describes the methodologies used for characterising exposure of children to EMF-NIR in the INMA (INfancia y Medio Ambiente- Environment and Childhood) Project, a prospective cohort study. Indirect (proximity to emission sources, questionnaires on sources use and geospatial propagation models) and direct methods (spot and fixed longer-term measurements and personal measurements) were conducted in order to assess exposure levels of study participants aged between 7 and 18 years old. The methodology used varies depending on the frequency of the EMF-NIR and the environment (homes, schools and parks). Questionnaires assessed the use of sources contributing both to Extremely Low Frequency (ELF) and Radiofrequency (RF) exposure levels. Geospatial propagation models (NISMap) are implemented and validated for environmental outdoor sources of RFs using spot measurements. Spot and fixed longer-term ELF and RF measurements were done in the environments where children spend most of the time. Moreover, personal measurements were taken in order to assess individual exposure to RF. The exposure data are used to explore their relationships with proximity and/or use of EMF-NIR sources. Characterisation of the EMF-NIR exposure by this combination of methods is intended to overcome problems encountered in other research. The assessment of exposure of INMA cohort children and adolescents living in different regions of Spain to the full frequency range of EMF-NIR extends the characterisation of environmental exposures in this cohort. Together with other data obtained in the project, on socioeconomic and family characteristics and development of the children and adolescents, this will enable to evaluate the complex

Conventional laboratory methods for cyanotoxins.

PubMed

Lawton, Linda A; Edwards, C

2008-01-01

It is clear from the literature that numerous methods are available for most cyanotoxins, although many publications on monitoring data indicate that the favored approach is the use proven, robust methods for individual toxins. The most effective approach is the utilization of a robust rapid screen, where positive samples are followed up by qualitative and quantitative analysis to provide the essential decision making data needed for successful management strategies (Fig. 2). Currently, rapid screens are available for microcystins, saxitoxins and anatoxin-a(s), whilst optimisation and validation is needed, many publications report good correlation with the mouse bioassay and HPLC. There is an urgent need for rapid, simple, and inexpensive assays for cylindrospermopsins, anatoxin-a and BMAA. Although methods exist for analysis of BMAA, the fact that a recent study showed 95% of cyanobacteria producing this, some at levels > 6,000 microg g(-1) dry wt, is of concern and rapid screening followed by robust analysis needed. An ideal approach would be a single method capable of extracting and detecting all cyanotoxins. Several publications describe such approaches using LC-MS, but as expected from a group of compounds with diverse chemistry, there are obvious limitations in recoveries during sample processing, chromatographic performance and sensitivity (Dahlmann et al. 2003, Dell'Aversano et al. 2004, Pietsch et al. 2001). Selection of methods must be based on the application requirements, equipment available and cost. For many organisations it may be more cost effective to out-source the occasional analysis. However, as the incidence of blooms appears to be increasing, the need for more rigorous monitoring is needed, sensible investment is needed to meet recommended guidelines. Most of the methods discussed in this paper are suitable for achieving this goal, although clean-up and concentration is usually necessary for physicochemical methods.

Internal audit in a microbiology laboratory.

PubMed Central

Mifsud, A J; Shafi, M S

1995-01-01

AIM--To set up a programme of internal laboratory audit in a medical microbiology laboratory. METHODS--A model of laboratory based process audit is described. Laboratory activities were examined in turn by specimen type. Standards were set using laboratory standard operating procedures; practice was observed using a purpose designed questionnaire and the data were analysed by computer; performance was assessed at laboratory audit meetings; and the audit circle was closed by re-auditing topics after an interval. RESULTS--Improvements in performance scores (objective measures) and in staff morale (subjective impression) were observed. CONCLUSIONS--This model of process audit could be applied, with amendments to take local practice into account, in any microbiology laboratory. PMID:7665701

Pterodon pubescens oil: characterisation, certification of origin and quality control via mass spectrometry fingerprinting analysis.

PubMed

Cabral, E C; Sevart, L; Spindola, H M; Coelho, M B; Sousa, I M O; Queiroz, N C A; Foglio, M A; Eberlin, M N; Riveros, J M

2013-02-01

The oil obtained from Pterodon pubescens (Leguminosae) seeds are known to display anti-cancer, anti-dermatogenic and anti-nociceptive activitiy. Phytochemical studies have demonstrated that its main constituents are diterpenoids with voucapan skeletons. Considering the potential biological activities of the oil, rapid and efficient methods for assessing its quality would facilitate certification and quality control. To develop a direct mass spectrometric fingerprinting method for the P. pubescens seed oil that would focus on the major diterpenoids constituents, enabling quality control, origin certification and recognition of marker species in commercially available products. Two techniques were used: (i) direct infusion electrospray ionisation (ESI) mass spectrometry after solvent extraction and dilution and (ii) ambient desorption/ionisation via easy ambient sonic-spray ionisation, EASI(+)-MS, performed directly on the seed surface or at a paper surface imprinted with the oil. From a combination of ESI-MS, HRESI-MS and ESI-MS/MS data, 12 diterpenes were characterised, and typical profiles were obtained for the oil extract or the crude oil via both ESI-MS and EASI-MS. These techniques require no or very simple sample preparation protocols and the whole analytical processes with spectra acquisition take just a few minutes. Both techniques, but particularly EASI-MS, provide simple, fast and efficient MS fingerprinting methodologies to characterise the P. pubescens oil with typical (di)terpene profiles being applicable to quality control and certification of authenticity and origin. Copyright © 2012 John Wiley & Sons, Ltd.

Geoelectrical characterisation of basement aquifers: the case of Iberekodo, southwestern Nigeria

NASA Astrophysics Data System (ADS)

Aizebeokhai, Ahzegbobor P.; Oyeyemi, Kehinde D.

2018-03-01

Basement aquifers, which occur within the weathered and fractured zones of crystalline bedrocks, are important groundwater resources in tropical and subtropical regions. The development of basement aquifers is complex owing to their high spatial variability. Geophysical techniques are used to obtain information about the hydrologic characteristics of the weathered and fractured zones of the crystalline basement rocks, which relates to the occurrence of groundwater in the zones. The spatial distributions of these hydrologic characteristics are then used to map the spatial variability of the basement aquifers. Thus, knowledge of the spatial variability of basement aquifers is useful in siting wells and boreholes for optimal and perennial yield. Geoelectrical resistivity is one of the most widely used geophysical methods for assessing the spatial variability of the weathered and fractured zones in groundwater exploration efforts in basement complex terrains. The presented study focuses on combining vertical electrical sounding with two-dimensional (2D) geoelectrical resistivity imaging to characterise the weathered and fractured zones in a crystalline basement complex terrain in southwestern Nigeria. The basement aquifer was delineated, and the nature, extent and spatial variability of the delineated basement aquifer were assessed based on the spatial variability of the weathered and fractured zones. The study shows that a multiple-gradient array for 2D resistivity imaging is sensitive to vertical and near-surface stratigraphic features, which have hydrological implications. The integration of resistivity sounding with 2D geoelectrical resistivity imaging is efficient and enhances near-surface characterisation in basement complex terrain.

Patients with primary insomnia in the sleep laboratory: do they present with typical nights of sleep?

PubMed

Hirscher, Verena; Unbehaun, Thomas; Feige, Bernd; Nissen, Christoph; Riemann, Dieter; Spiegelhalder, Kai

2015-08-01

The validity of sleep laboratory investigations in patients with insomnia is important for researchers and clinicians. The objective of this study was to examine the first-night effect and the reverse first-night effect in patients with chronic primary insomnia compared with good sleeper controls. A retrospective comparison of a well-characterised sample of 50 patients with primary insomnia and 50 good sleeper controls was conducted with respect to 2 nights of polysomnography, and subjective sleep parameters in the sleep laboratory and the home setting. When comparing the first and second sleep laboratory night, a significant first-night effect was observed across both groups in the great majority of the investigated polysomnographic and subjective variables. However, patients with primary insomnia and good sleeper controls did not differ with respect to this effect. Regarding the comparison between the sleep laboratory nights and the home setting, unlike good sleeper controls, patients with primary insomnia reported an increased subjective sleep efficiency on both nights (in part due to a reduced bed time) and an increased subjective total sleep time on the second night. These results suggest that even the second sleep laboratory night does not necessarily provide clinicians and researchers with a representative insight into the sleep perception of patients with primary insomnia. Future studies should investigate whether these findings also hold for other patient populations. © 2015 European Sleep Research Society.

Functional characterisation of metal(loid) processes in planta through the integration of synchrotron techniques and plant molecular biology

PubMed Central

Donner, Erica; Punshon, Tracy; Guerinot, Mary Lou; Lombi, Enzo

2013-01-01

Functional characterisation of the genes regulating metal(loid) homeostasis in plants is a major focus of crop biofortification, phytoremediation, and food security research. This paper focuses on the potential for advancing plant metal(loid) research by combining molecular biology and synchrotron-based techniques. Recent advances in x-ray focussing optics and fluorescence detection have greatly improved the potential of synchrotron techniques for plant science research, allowing metal(loids) to be imaged in vivo in hydrated plant tissues at sub-micron resolution. Laterally resolved metal(loid) speciation can also be determined. By using molecular techniques to probe the location of gene expression and protein localisation and combining it with this synchrotron-derived data, functional information can be effectively and efficiently assigned to specific genes. This paper provides a review of the state of the art in this field, and provides examples as to how synchrotron-based methods can be combined with molecular techniques to facilitate functional characterisation of genes in planta. PMID:22200921

Creating and Evaluating a Hypertext System of Documenting Analytical Test Methods in a Chemical Plant Quality Assurance Laboratory.

ERIC Educational Resources Information Center

White, Charles E., Jr.

The purpose of this study was to develop and implement a hypertext documentation system in an industrial laboratory and to evaluate its usefulness by participative observation and a questionnaire. Existing word-processing test method documentation was converted directly into a hypertext format or "hyperdocument." The hyperdocument was designed and…

Brillouin characterisation of optical microfibers

NASA Astrophysics Data System (ADS)

Farhan, Kazi Tasneem

The sleek shape of microfiber helps it to confine the light tightly and generate high nonlinear effect, which is 1000 times higher than the standard fiber. This project focuses on fabricating microfiber samples with different taper lengths and different waist diameter from three different kinds of fiber, single mode fiber (SMF), Gedoped and Ga-doped. All the samples were characterised in terms of Brillouin scattering and Brillouin gain and Brillouin lasing, and compared to each other and to the SMF fiber. Stimulated Brillouin scattering (SBS) has been demonstrated for short microfibers of length less than 10cm. The nonlinear effects of long tapers have not been reported yet. The theoretical perspective related to microfibers indicate the possibility of generation of stronger signals and newer frequencies. Among the many nonlinear effects Brillouin scattering is the easiest to observe and has not been studied using long microfibers until now. In this project microfibers of different lengths and waist diameter are fabricated. The microfibers were made from three different kinds of fiber: SMF, Germanium doped (Ge-doped) and Gallium doped (Ga-doped). The shapes of the fabricated samples are profiled to match the shape with the numerically simulated shape. The power performances are studied so that samples with minimum losses are used for Brillouin characterisation. The first experiment uses the microfiber samples for testing and recording the changes in Stokes generation for the different dimensions of each sample in a Brillouin scattering setup. These microfibers are tested in s second experiment of Brillouin laser setup to explore their possibilities of lasing. In the third experiment the microfibers are used in a pump probe technique setup to spatially measure the Brillouin gain along the length of each sample.

Development and Single-Laboratory Validation of a Liquid Chromatography Tandem Mass Spectrometry Method for Quantitation of Tetrodotoxin in Mussels and Oysters.

PubMed

Turner, Andrew D; Boundy, Michael J; Rapkova, Monika Dhanji

2017-09-01

In recent years, evidence has grown for the presence of tetrodotoxin (TTX) in bivalve mollusks, leading to the potential for consumers of contaminated products to be affected by Tetrodotoxin Shellfish Poisoning (TSP). A single-laboratory validation was conducted for the hydrophilic interaction LC (HILIC) tandem MS (MS/MS) analysis of TTX in common mussels and Pacific oysters-the bivalve species that have been found to contain TTXs in the United Kingdom in recent years. The method consists of a single-step dispersive extraction in 1% acetic acid, followed by a carbon SPE cleanup step before dilution and instrumental analysis. The full method was developed as a rapid tool for the quantitation of TTX, as well as for the associated analogs 4-epi-TTX; 5,6,11-trideoxy TTX; 11-nor TTX-6-ol; 5-deoxy TTX; and 4,9-anhydro TTX. The method can also be run as the acquisition of TTX together with paralytic shellfish toxins. Results demonstrated acceptable method performance characteristics for specificity, linearity, recovery, ruggedness, repeatability, matrix variability, and within-laboratory reproducibility for the analysis of TTX. The LOD and LOQ were fit-for-purpose in comparison to the current action limit for TTX enforced in The Netherlands. In addition, aspects of method performance (LOD, LOQ, and within-laboratory reproducibility) were found to be satisfactory for three other TTX analogs (11-nor TTX-6-ol, 5-deoxy TTX, and 4,9-anhydro TTX). The method was found to be practical and suitable for use in regulatory testing, providing rapid turnaround of sample analysis. Plans currently underway on a full collaborative study to validate a HILIC-MS/MS method for paralytic shellfish poisoning toxins will be extended to include TTX in order to generate international acceptance, ultimately for use as an alternative official control testing method should regulatory controls be adopted.

Biosynthesis of silver and platinum nanoparticles using orange peel extract: characterisation and applications.

PubMed

Castro, Laura; Blázquez, María Luisa; González, Felisa; Muñoz, Jesús Ángel; Ballester, Antonio

2015-10-01

This study focuses on the green synthesis of noble metal nanoparticles (silver (Ag) and platinum (Pt)) and how the size and shape of the nanoparticles produced can be controlled through changes in the initial pH value of the precursor solution. The nanoparticles were characterised by ultra-violet-visible spectroscopy, transmission electron microscopy and X-ray diffraction. This simple and environmentally friendly method allows the synthesis of diverse nanostructures in the absence of a surfactant or polymer to direct nanoparticle growth, and without externally adding seed crystallites. The antibacterial effects of Ag nanoparticles and catalytic properties of Pt nanoparticles were explored for future promising biotechnological approaches in different fields.

Determining the Transference Number of H[superscript +](aq) by a Modified Moving Boundary Method: A Directed Study for the Undergraduate Physical Chemistry Laboratory

ERIC Educational Resources Information Center

Dabke, Rajeev B.; Gebeyehu, Zewdu; Padelford, Jonathan

2012-01-01

A directed study for the undergraduate physical chemistry laboratory for determining the transference number of H[superscript +](aq) using a modified moving boundary method is presented. The laboratory study combines Faraday's laws of electrolysis with mole ratios and the perfect gas equation. The volume of hydrogen gas produced at the cathode is…

Characterising Passive Dosemeters for Dosimetry of Biological Experiments in Space (dobies)

NASA Astrophysics Data System (ADS)

Vanhavere, Filip; Spurny, Frantisek; Yukihara, Eduardo; Genicot, Jean-Louis

Introduction: The DOBIES (Dosimetry of biological experi-ments in space) project focusses on the use of a stan-dard dosimetric method (as a combination of differ-ent passive techniques) to measure accurately the absorbed doses and equivalent doses in biological samples. Dose measurements on biological samples are of high interest in the fields of radiobiology and exobiology. Radiation doses absorbed by biological samples must be quantified to be able to determine the relationship between observed biological effects and the radiation dose. The radiation field in space is very complex, con-sisting of protons, neutrons, electrons and high-energy heavy charged particles. It is not straightfor-ward to measure doses in this radiation field, cer-tainly not with only small and light passive doseme-ters. The properties of the passive detectors must be tested in radiation fields that are representative of the space radiation. We will report on the characterisation of different type of passive detectors at high energy fields. The results from such characterisation measurements will be applied to recent exposures of detectors on the International Space Station. Material and methods: Following passive detectors are used: • thermoluminescent detectors (TLD) • optically stimulated luminescence detectors (OSLD) • track etch detectors (TED) The different groups have participated in the past to the ICCHIBAN series of irradiations. Here protons and other particles of high energy were used to de-termine the LET-dependency of the passive detec-tors. The last few months, new irradiations have been done at the iThemba labs (100-200 MeV protons), Dubna (145 MeV protons) and the JRC-IRMM (quasi mono energetic neutrons up to 19 MeV). All these detectors were also exposed to a simulated space radiation field at CERN (CERF-field). Discussion: The interpretation of the TLD and OSLD results is done using the measured LET spectrum (TED) and the LET-dependency curves of ths TLD and OSLDs

Physico-chemical characterisation of material fractions in household waste: Overview of data in literature.

PubMed

Götze, Ramona; Boldrin, Alessio; Scheutz, Charlotte; Astrup, Thomas Fruergaard

2016-03-01

State-of-the-art environmental assessment of waste management systems rely on data for the physico-chemical composition of individual material fractions comprising the waste in question. To derive the necessary inventory data for different scopes and systems, literature data from different sources and backgrounds are consulted and combined. This study provides an overview of physico-chemical waste characterisation data for individual waste material fractions available in literature and thereby aims to support the selection of data fitting to a specific scope and the selection of uncertainty ranges related to the data selection from literature. Overall, 97 publications were reviewed with respect to employed characterisation method, regional origin of the waste, number of investigated parameters and material fractions and other qualitative aspects. Descriptive statistical analysis of the reported physico-chemical waste composition data was performed to derive value ranges and data distributions for element concentrations (e.g. Cd content) and physical parameters (e.g. heating value). Based on 11,886 individual data entries, median values and percentiles for 47 parameters in 11 individual waste fractions are presented. Exceptional values and publications are identified and discussed. Detailed datasets are attached to this study, allowing further analysis and new applications of the data. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rabies in Iraq: Trends in Human Cases 2001–2010 and Characterisation of Animal Rabies Strains from Baghdad

PubMed Central

Horton, Daniel L.; Ismail, Mashair Z.; Siryan, Eman S.; Wali, Abdul Raheem A.; Ab-dulla, Husam E.; Wise, Emma; Voller, Katja; Harkess, Graeme; Marston, Denise A.; McElhinney, Lorraine M.; Abbas, Salah F.; Fooks, Anthony R.

2013-01-01

Control of rabies requires a consistent supply of dependable resources, constructive cooperation between veterinary and public health authorities, and systematic surveillance. These are challenging in any circumstances, but particularly during conflict. Here we describe available human rabies surveillance data from Iraq, results of renewed sampling for rabies in animals, and the first genetic characterisation of circulating rabies strains from Iraq. Human rabies is notifiable, with reported cases increasing since 2003, and a marked increase in Baghdad between 2009 and 2010. These changes coincide with increasing numbers of reported dog bites. There is no laboratory confirmation of disease or virus characterisation and no systematic surveillance for rabies in animals. To address these issues, brain samples were collected from domestic animals in the greater Baghdad region and tested for rabies. Three of 40 brain samples were positive using the fluorescent antibody test and hemi-nested RT-PCR for rabies virus (RABV). Bayesian phylogenetic analysis using partial nucleoprotein gene sequences derived from the samples demonstrated the viruses belong to a single virus variant and share a common ancestor with viruses from neighbouring countries, 22 (95% HPD 14–32) years ago. These include countries lying to the west, north and east of Iraq, some of which also have other virus variants circulating concurrently. These results suggest possible multiple introductions of rabies into the Middle East, and regular trans-boundary movement of disease. Although 4000 years have passed since the original description of disease consistent with rabies, animals and humans are still dying of this preventable and neglected zoonosis. PMID:23469303

Production, characterisation, and in vitro nebulisation performance of budesonide-loaded PLA nanoparticles.

PubMed

Amini, Mohammad Ali; Faramarzi, Mohammad Ali; Gilani, Kambiz; Moazeni, Esmaeil; Esmaeilzadeh-Gharehdaghi, Elina; Amani, Amir

2014-01-01

The aim of this study is to prepare a nanosuspension of budesonide for respiratory delivery using nebuliser by optimising its particle size and characterising its in vitro deposition behaviour. PLA (poly lactic acid)-budesonide nanosuspension (BNS) was prepared using high-pressure emulsification/solvent evaporation method. To optimise particle size, different parameters such as PLA concentration, sonication time, and amplitude were investigated. Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and scanning electron microscope (SEM) analyses were performed to characterise the prepared PLA-budesonide nanoparticles. The in vitro aerodynamic characteristics of the PLA-BNS using a jet nebuliser were estimated and compared with that of commercially available suspension formulation of budesonide. Budesonide-loaded PLA nanoparticles with fine particle size (an average size of 224-360 nm), narrow size distribution, and spherical and smooth surface were prepared. The optimum condition for preparation of fine particle size for aerosolisation was found to be at PLA concentration of 1.2 mg/ml and amplitude of 70 for 75 s sonication time. The in vitro aerosolisation performance of PLA-BNS compared to that of commercial budesonide indicated that it has significantly (p < 0.05) smaller mass median aerodynamic diameter (MMAD) value with an enhancement in fine particle fraction (FPF) value. Improving the in vitro deposition of budesonide, PLA-BNS could be considered as a promising alternative suspension formulation for deep lung delivery of the drug using nebuliser.

Diagnostic accuracy of ultrasonography, MRI and MR arthrography in the characterisation of rotator cuff disorders: a systematic review and meta-analysis

PubMed Central

Roy, Jean-Sébastien; Braën, Caroline; Leblond, Jean; Desmeules, François; Dionne, Clermont E; MacDermid, Joy C; Bureau, Nathalie J; Frémont, Pierre

2015-01-01

Background Different diagnostic imaging modalities, such as ultrasonography (US), MRI, MR arthrography (MRA) are commonly used for the characterisation of rotator cuff (RC) disorders. Since the most recent systematic reviews on medical imaging, multiple diagnostic studies have been published, most using more advanced technological characteristics. The first objective was to perform a meta-analysis on the diagnostic accuracy of medical imaging for characterisation of RC disorders. Since US is used at the point of care in environments such as sports medicine, a secondary analysis assessed accuracy by radiologists and non-radiologists. Methods A systematic search in three databases was conducted. Two raters performed data extraction and evaluation of risk of bias independently, and agreement was achieved by consensus. Hierarchical summary receiver-operating characteristic package was used to calculate pooled estimates of included diagnostic studies. Results Diagnostic accuracy of US, MRI and MRA in the characterisation of full-thickness RC tears was high with overall estimates of sensitivity and specificity over 0.90. As for partial RC tears and tendinopathy, overall estimates of specificity were also high (>0.90), while sensitivity was lower (0.67–0.83). Diagnostic accuracy of US was similar whether a trained radiologist, sonographer or orthopaedist performed it. Conclusions Our results show the diagnostic accuracy of US, MRI and MRA in the characterisation of full-thickness RC tears. Since full thickness tear constitutes a key consideration for surgical repair, this is an important characteristic when selecting an imaging modality for RC disorder. When considering accuracy, cost, and safety, US is the best option. PMID:25677796

A framework for assessment and characterisation of municipal solid waste landfill leachate: an application to the Turbhe landfill, Navi Mumbai, India.

PubMed

Mishra, Harshit; Rathod, Merwan; Karmakar, Subhankar; Kumar, Rakesh

2016-06-01

Rapid industrialisation, growing population and changing lifestyles are the root causes for the generation of huge amounts of solid waste in developing countries. In India, disposal of municipal solid waste (MSW) through open dumping is the most common waste disposal method. Unfortunately, leachate generation from landfill is high due to the prolonged and prominent monsoon season in India. As leachate generation rate is high in most of the tropical countries, long-term and extensive monitoring efforts are expected to evaluate actual environmental pollution potential due to leachate contamination. However, the leachate characterisation involves a comprehensive process, which has numerous shortcomings and uncertainties possibly due to the complex nature of landfilling process, heterogeneous waste characteristics, widely varying hydrologic conditions and selection of analytes. In order to develop a sustainable MSW management strategy for protecting the surface and ground water resources, particularly from MSW landfill leachate contamination, assessment and characterisation of leachate are necessary. Numerous studies have been conducted in the past to characterise leachate quality from various municipal landfills; unfortunately, none of these propose a framework or protocol. The present study proposes a generic framework for municipal landfill leachate assessment and characterisation. The proposed framework can be applied to design any type of landfill leachate quality monitoring programme and also to facilitate improved leachate treatment activities. A landfill site located at Turbhe, Navi Mumbai, India, which had not been investigated earlier, has been selected as a case study. The proposed framework has been demonstrated on the Turbhe landfill site which is a comparatively new and the only sanitary landfill in Navi Mumbai.

A novel textile characterisation approach using an embedded sensor system and segmented textile manipulation

NASA Astrophysics Data System (ADS)

Fial, Julian; Carosella, Stefan; Langheinz, Mario; Wiest, Patrick; Middendorf, Peter

2018-05-01

This paper investigates the application of sensors on carbon fibre textiles for the purpose of textile characterisation and draping process optimisation. The objective is to analyse a textile's condition during the draping operation and actively manipulate boundary conditions in order to create better preform qualities. Various realisations of textile integrated sensors are presented, focusing on the measurement of textile strain. Furthermore, a complex textile characterisation approach is presented where these sensors shall be implemented in.

Fabrication and characterisation of a novel biomimetic anisotropic ceramic/polymer-infiltrated composite material.

PubMed

Al-Jawoosh, Sara; Ireland, Anthony; Su, Bo

2018-04-10

To fabricate and characterise a novel biomimetic composite material consisting of aligned porous ceramic preforms infiltrated with polymer. Freeze-casting was used to fabricate and control the microstructure and porosity of ceramic preforms, which were subsequently infiltrated with 40-50% by volume UDMA-TEGDMA polymer. The composite materials were then subjected to characterisation, namely density, compression, three-point bend, hardness and fracture toughness testing. Samples were also subjected to scanning electron microscopy and computerised tomography (Micro-CT). Three-dimensional aligned honeycomb-like ceramic structures were produced and full interpenetration of the polymer phase was observed using micro-CT. Depending on the volume fraction of the ceramic preform, the density of the final composite ranged from 2.92 to 3.36g/cm 3 , compressive strength ranged from 206.26 to 253.97MPa, flexural strength from 97.73 to 145.65MPa, hardness ranged from 1.46 to 1.62GPa, and fracture toughness from 3.91 to 4.86MPam 1/2 . Freeze-casting provides a novel method to engineer composite materials with a unique aligned honeycomb-like interpenetrating structure, consisting of two continuous phases, inorganic and organic. There was a correlation between the ceramic fraction and the subsequent, density, strength, hardness and fracture toughness of the composite material. Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

Synthesis, X-ray characterisation and reactions of a trigonal planar palladium(0) carbonyl complex, (tbpx)PdCO.

PubMed

Bellabarba, Ronan M; Tooze, Robert P; Slawin, Alexandra M Z

2003-08-07

The novel complex (tbpx)PdCO (1), the first example of a structurally characterised sixteen electron, trigonal planar palladium(0) carbonyl complex, was prepared, characterised by NMR spectroscopy and X-ray crystallography, and some unusual aspects of its reactivity were studied.

Evaluation of a bioluminescence method, contact angle measurements and topography for testing the cleanability of plastic surfaces under laboratory conditions

NASA Astrophysics Data System (ADS)

Redsven, I.; Kymäläinen, H.-R.; Pesonen-Leinonen, E.; Kuisma, R.; Ojala-Paloposki, T.; Hautala, M.; Sjöberg, A.-M.

2007-04-01

Detection of adenosine triphosphate (ATP) by bioluminescence is used, for instance, in the food industry and in hospitals to assess the hygiene status of surfaces. The aim of this laboratory study was to investigate the feasibility of the ATP method for estimating the cleanability of resilient floor coverings from biological soil. The surfaces were worn using a Soiling and Wearing Drum Tester, and soiled and cleaned with an Erichsen Washability and Scrubbing Resistance Tester. In the laboratory test carried out with the bioluminescence method, most of the new and worn floor coverings that were biologically soiled were cleaned efficiently. According to this study, the semiquantitative ATP screening method can be used for hygiene monitoring of flooring materials. No correlation was found between cleanability and contact angles or surface topography measured using a profilometer. However, by revealing local irregularities and damage on surfaces, scanning electron micrographs appeared useful in explaining differences in cleanability.

Quality in the molecular microbiology laboratory.

PubMed

Wallace, Paul S; MacKay, William G

2013-01-01

In the clinical microbiology laboratory advances in nucleic acid detection, quantification, and sequence analysis have led to considerable improvements in the diagnosis, management, and monitoring of infectious diseases. Molecular diagnostic methods are routinely used to make clinical decisions based on when and how to treat a patient as well as monitor the effectiveness of a therapeutic regime and identify any potential drug resistant strains that may impact on the long term patient treatment program. Therefore, confidence in the reliability of the result provided by the laboratory service to the clinician is essential for patient treatment. Hence, suitable quality assurance and quality control measures are important to ensure that the laboratory methods and service meet the necessary regulatory requirements both at the national and international level. In essence, the modern clinical microbiology laboratory ensures the appropriateness of its services through a quality management system that monitors all aspects of the laboratory service pre- and post-analytical-from patient sample receipt to reporting of results, from checking and upholding staff competency within the laboratory to identifying areas for quality improvements within the service offered. For most European based clinical microbiology laboratories this means following the common International Standard Organization (ISO9001) framework and ISO15189 which sets out the quality management requirements for the medical laboratory (BS EN ISO 15189 (2003) Medical laboratories-particular requirements for quality and competence. British Standards Institute, Bristol, UK). In the United States clinical laboratories performing human diagnostic tests are regulated by the Centers for Medicare and Medicaid Services (CMS) following the requirements within the Clinical Laboratory Improvement Amendments document 1988 (CLIA-88). This chapter focuses on the key quality assurance and quality control requirements within the

Analytical methods of the U.S. Geological Survey's New York District Water-Analysis Laboratory

USGS Publications Warehouse

Lawrence, Gregory B.; Lincoln, Tricia A.; Horan-Ross, Debra A.; Olson, Mark L.; Waldron, Laura A.

1995-01-01

The New York District of the U.S. Geological Survey (USGS) in Troy, N.Y., operates a water-analysis laboratory for USGS watershed-research projects in the Northeast that require analyses of precipitation and of dilute surface water and soil water for major ions; it also provides analyses of certain chemical constituents in soils and soil gas samples.This report presents the methods for chemical analyses of water samples, soil-water samples, and soil-gas samples collected in wateshed-research projects. The introduction describes the general materials and technicques for each method and explains the USGS quality-assurance program and data-management procedures; it also explains the use of cross reference to the three most commonly used methods manuals for analysis of dilute waters. The body of the report describes the analytical procedures for (1) solution analysis, (2) soil analysis, and (3) soil-gas analysis. The methods are presented in alphabetical order by constituent. The method for each constituent is preceded by (1) reference codes for pertinent sections of the three manuals mentioned above, (2) a list of the method's applications, and (3) a summary of the procedure. The methods section for each constitutent contains the following categories: instrumentation and equipment, sample preservation and storage, reagents and standards, analytical procedures, quality control, maintenance, interferences, safety considerations, and references. Sufficient information is presented for each method to allow the resulting data to be appropriately used in environmental investigations.

The ideal laboratory information system.

PubMed

Sepulveda, Jorge L; Young, Donald S

2013-08-01

Laboratory information systems (LIS) are critical components of the operation of clinical laboratories. However, the functionalities of LIS have lagged significantly behind the capacities of current hardware and software technologies, while the complexity of the information produced by clinical laboratories has been increasing over time and will soon undergo rapid expansion with the use of new, high-throughput and high-dimensionality laboratory tests. In the broadest sense, LIS are essential to manage the flow of information between health care providers, patients, and laboratories and should be designed to optimize not only laboratory operations but also personalized clinical care. To list suggestions for designing LIS with the goal of optimizing the operation of clinical laboratories while improving clinical care by intelligent management of laboratory information. Literature review, interviews with laboratory users, and personal experience and opinion. Laboratory information systems can improve laboratory operations and improve patient care. Specific suggestions for improving the function of LIS are listed under the following sections: (1) Information Security, (2) Test Ordering, (3) Specimen Collection, Accessioning, and Processing, (4) Analytic Phase, (5) Result Entry and Validation, (6) Result Reporting, (7) Notification Management, (8) Data Mining and Cross-sectional Reports, (9) Method Validation, (10) Quality Management, (11) Administrative and Financial Issues, and (12) Other Operational Issues.

Comparison between active (pumped) and passive (diffusive) sampling methods for formaldehyde in pathology and histology laboratories.

PubMed

Lee, Eun Gyung; Magrm, Rana; Kusti, Mohannad; Kashon, Michael L; Guffey, Steven; Costas, Michelle M; Boykin, Carie J; Harper, Martin

2017-01-01

This study was to determine occupational exposures to formaldehyde and to compare concentrations of formaldehyde obtained by active and passive sampling methods. In one pathology and one histology laboratories, exposure measurements were collected with sets of active air samplers (Supelco LpDNPH tubes) and passive badges (ChemDisk Aldehyde Monitor 571). Sixty-six sample pairs (49 personal and 17 area) were collected and analyzed by NIOSH NMAM 2016 for active samples and OSHA Method 1007 (using the manufacturer's updated uptake rate) for passive samples. All active and passive 8-hr time-weighted average (TWA) measurements showed compliance with the OSHA permissible exposure limit (PEL-0.75 ppm) except for one passive measurement, whereas 78% for the active and 88% for the passive samples exceeded the NIOSH recommended exposure limit (REL-0.016 ppm). Overall, 73% of the passive samples showed higher concentrations than the active samples and a statistical test indicated disagreement between two methods for all data and for data without outliers. The OSHA Method cautions that passive samplers should not be used for sampling situations involving formalin solutions because of low concentration estimates in the presence of reaction products of formaldehyde and methanol (a formalin additive). However, this situation was not observed, perhaps because the formalin solutions used in these laboratories included much less methanol (3%) than those tested in the OSHA Method (up to 15%). The passive samplers in general overestimated concentrations compared to the active method, which is prudent for demonstrating compliance with an occupational exposure limit, but occasional large differences may be a result of collecting aerosolized droplets or splashes on the face of the samplers. In the situations examined in this study the passive sampler generally produces higher results than the active sampler so that a body of results from passive samplers demonstrating compliance with the

Noise Emission from Laboratory Air Blowers

ERIC Educational Resources Information Center

Rossing, Thomas D.; Windham, Betty

1978-01-01

Product noise ratings for a number of laboratory air blowers are reported and several recommendations for reducing laboratory noise from air blowers are given. Relevant noise ratings and methods for measuring noise emission of appliances are discussed. (BB)

Predictive performance and inter-laboratory reproducibility in assessing eye irritation potential of water- and oil-soluble mixtures using the Short Time Exposure test method.

PubMed

Abo, Takayuki; Hilberer, Allison; Behle-Wagner, Christine; Watanabe, Mika; Cameron, David; Kirst, Annette; Nukada, Yuko; Yuki, Takuo; Araki, Daisuke; Sakaguchi, Hitoshi; Itagaki, Hiroshi

2018-04-01

The Short Time Exposure (STE) test method is an alternative method for assessing eye irritation potential using Statens Seruminstitut Rabbit Cornea cells and has been adopted as test guideline 491 by the Organisation for Economic Co-operation and Development. Its good predictive performance in identifying the Globally Harmonized System (GHS) No Category (NC) or Irritant Category has been demonstrated in evaluations of water-soluble substances, oil-soluble substances, and water-soluble mixtures. However, the predictive performance for oil-soluble mixtures was not evaluated. Twenty-four oil-soluble mixtures were evaluated using the STE test method. The GHS NC or Irritant Category of 22 oil-soluble mixtures were consistent with that of a Reconstructed human Cornea-like Epithelium (RhCE) test method. Inter-laboratory reproducibility was then confirmed using 20 water- and oil-soluble mixtures blind-coded. The concordance in GHS NC or Irritant Category among four laboratories was 90%-100%. In conclusion, the concordance in comparison with the results of RhCE test method using 24 oil-soluble mixtures and inter-laboratory reproducibility using 20 water- and oil-soluble mixtures blind-coded were good, indicating that the STE test method is a suitable alternative for predicting the eye irritation potential of both substances and mixtures. Copyright © 2018 Elsevier Ltd. All rights reserved.

Characterisation of the Interaction between Toroidal Vortex Structures and Flame Front Propagation

NASA Astrophysics Data System (ADS)

Long, E. J.; Hargrave, G. K.; Jarvis, S.; Justham, T.; Halliwell, N.

2006-07-01

Experimental laser diagnostic data is presented for flame characterisation during interactions with toroidal vortices generated in the wake of an annular obstacle. A novel twin section combustion chamber has been utilised to allow the controlled formation of stable eddy structures into which a flame front can propagate. High speed laser sheet visualisation was employed to record the flow field and flame front temporal development and high-speed digital particle image velocimetry was used to quantify the velocity field of the unburnt mixture ahead of the flame front. Results provide characterisation of the toroidal vortex/flame front interaction for a range of vortex scales of and recirculation strengths.

Laboratory method used for bioremediation

DOEpatents

Carman, M. Leslie; Taylor, Robert T.

2000-01-01

An improved method for in situ microbial filter bioremediation having increasingly operational longevity of an in situ microbial filter emplaced into an aquifer. A method for generating a microbial filter of sufficient catalytic density and thickness, which has increased replenishment interval, improved bacteria attachment and detachment characteristics and the endogenous stability under in situ conditions. A system for in situ field water remediation.

Operational impact of using a vanadate oxidase method for direct bilirubin measurements at an academic medical center clinical laboratory.

PubMed

Dhungana, Neha; Morris, Cory; Krasowski, Matthew D

2017-08-01

The aim of this study was to compare the operational impact of using vanadate oxidase versus diazo direct bilirubin assays for an academic medical center patient population. Retrospective study was done over an approximately 3.5 year period. The main automated chemistry instrumentation was a Roche Diagnostics cobas 8000 line. The Roche Direct Bilirubin assay was compared to Diazyme Laboratories Direct Bilirubin Assay and Randox Laboratories Direct Bilirubin assay using manufacturer's guidelines for hemolysis index, lipemia index, and analytical measurement range (AMR). Retrospective data was analyzed for 47,333 serum/plasma specimens that had clinical orders for direct bilirubin. A total of 5943 specimens (12.6%) exceeded the hemolysis index limit for the Roche method compared to only 0.2% and 0.05% of specimens for the Diazyme and Randox methods, respectively. The impact was particularly large on patients less than 2 years old, for which 51.3% of specimens exceeded the hemolysis index for the Roche method. A total of 1671 specimens (3.5%) exceeded the lipemia index limit for the Roche method compared to less than 0.1% for the Randox method. Lastly, 988 (2.1%) of specimens had direct bilirubin concentrations exceeding the upper AMR limit of 10 mg/dL [171 µmol/L] for the Roche assay compared to less than 1% of specimens for the vanadate oxidase methods. Vanadate oxidase direct bilirubin methods offer advantages over diazo methods in terms of less interference by hemolysis and lipemia, as well as wider AMR. The advantages are particularly evident for neonatal and infant populations.

A blueprint for the synthesis and characterisation of thin graphene oxide with controlled lateral dimensions for biomedicine

NASA Astrophysics Data System (ADS)

Filipe Rodrigues, Artur; Newman, Leon; Lozano, Neus; Mukherjee, Sourav P.; Fadeel, Bengt; Bussy, Cyrill; Kostarelos, Kostas

2018-07-01

Graphene-based materials (GBMs) have ignited a revolution in material science and technology, with electronic, optical and mechanical properties that are of relevant interest for a wide range of applications. To support the development of these enabling technologies, a global research effort has been invested to assess their hazard and biocompatibility. Different production methods have however generated a diverse collection of GBMs with different physicochemical properties, leading to a variety of biological outcomes that are still not fully understood. To better understand the biological interactions of GBMs with biological systems and allow the design of safer materials, a thorough physicochemical characterisation is therefore highly recommended. The aim of the present work was to produce a blueprint for the synthesis and characterisation of non-pyrogenic graphene oxide (GO) flakes with three different controlled lateral dimensions, which could be further used for either hazard assessment or biomedical proof-of-concept studies. A battery of techniques used to characterise the physicochemical properties of the GO samples included atomic force microscopy, transmission electron microscopy, Fourier-transformed infra-red spectroscopy, x-ray photoelectron spectroscopy and Raman spectroscopy. The combination of these different techniques confirmed that only the lateral dimension varied among the GO materials produced, without significant change in any other of their fundamental physicochemical properties, such as the thickness or surface chemistry. The proposed systematic approach in GO batch production for biology will hopefully contribute to a better understanding of the material properties that govern their interactions with biological systems and offer a blueprint towards standardisation of biologically relevant 2D materials.

Tetrahymena in the laboratory: strain resources, methods for culture, maintenance, and storage.

PubMed

Cassidy-Hanley, Donna M

2012-01-01

The ciliated protozoan Tetrahymena thermophila has been an important model system for biological research for many years. During that time, a variety of useful strains, including highly inbred stocks, a collection of diverse mutant strains, and wild cultivars from a variety of geographical locations have been identified. In addition, thanks to the efforts of many different laboratories, optimal conditions for growth, maintenance, and storage of Tetrahymena have been worked out. To facilitate the efficient use of Tetrahymena, especially by those new to the system, this chapter presents a brief description of many available Tetrahymena strains and lists possible resources for obtaining viable cultures of T. thermophila and other Tetrahymena species. Descriptions of commonly used media, methods for cell culture and maintenance, and protocols for short- and long-term storage are also presented. Copyright © 2012 Elsevier Inc. All rights reserved.

Archimedes' principle for characterisation of recombinant whole cell biocatalysts.

PubMed

Schmitt, Steven; Walser, Marcel; Rehmann, Michael; Oesterle, Sabine; Panke, Sven; Held, Martin

2018-02-14

The ability of whole cells to catalyse multistep reactions, often yielding synthetically demanding compounds later used by industrial biotech or pharma, makes them an indispensable tool of synthetic chemistry. The complex reaction network employed by cellular catalysts and the still only moderate predictive power of modelling approaches leaves this tool challenging to engineer. Frequently, large libraries of semi-rationally generated variants are sampled in high-throughput mode in order to then identify improved catalysts. We present a method for space- and time-efficient processing of very large libraries (10 7 ) of recombinant cellular catalysts, in which the phenotypic characterisation and the isolation of positive variants for the entire library is done within one minute in a single, highly parallelized operation. Specifically, product formation in nanolitre-sized cultivation vessels is sensed and translated into the formation of catalase as a reporter protein. Exposure to hydrogen peroxide leads to oxygen gas formation and thus to a density shift of the cultivation vessel. Exploiting Archimedes' principle, this density shift and the resulting upward buoyancy force can be used for batch-wise library sampling. We demonstrate the potential of the method for both, screening and selection protocols, and envision a wide applicability of the system for biosensor-based assays.

Simple optical method of qualitative assessment of sperm motility: preliminary results

NASA Astrophysics Data System (ADS)

Sozanska, Agnieszka; Kolwas, Krystyna; Galas, Jacek; Blocki, Narcyz; Czyzewski, Adam

2005-09-01

The examination of quality of the sperm ejaculate is one of the most important steps in artificial fertilization procedure. The main aim of semen storage centres is to characterise the best semen quality for fertilization. Reliable information about sperm motility is also one the most important parameters for in vitro laboratory procedures. There exist very expensive automated methods for semen analysis but they are unachievable for most of laboratories and semen storage centres. Motivation for this study is to elaborate a simple, cheap, objective and repeatable method for semen motility assessment. The method enables to detect even small changes in motility introduced by medical, physical or chemical factors. To test the reliability of the method we used cryopreserved bull semen from Lowicz Semen Storage Centre. The examined sperm specimen was warmed in water bath and then centrifuged. The best semen was collected by the swim-up technique and diluted to a proper concentration. Several semen concentrations and dilutions were tested in order to find the best probe parameters giving repeatable results. For semen visualization we used the phase-contrast microscope with a CCD camera. A PC computer was used to acquire and to analyse the data. The microscope table equipped with a microscope glass pool 0.7mm deep instead of some conventional plane microscope slides was stabilised at the temperature of 37°C. The main idea of our method is based on a numerical processing of the optical contrast of the sperm images which illustrates the dynamics of the sperm cells movement and on appropriate analysis of a grey scale level of the superimposed images. An elaborated numerical algorithm allows us to find the relative amount of motile sperm cells. The proposed method of sperm motility assessment seems to be objective and repeatable.

Non-structural carbohydrates in woody plants compared among laboratories.

PubMed

Quentin, Audrey G; Pinkard, Elizabeth A; Ryan, Michael G; Tissue, David T; Baggett, L Scott; Adams, Henry D; Maillard, Pascale; Marchand, Jacqueline; Landhäusser, Simon M; Lacointe, André; Gibon, Yves; Anderegg, William R L; Asao, Shinichi; Atkin, Owen K; Bonhomme, Marc; Claye, Caroline; Chow, Pak S; Clément-Vidal, Anne; Davies, Noel W; Dickman, L Turin; Dumbur, Rita; Ellsworth, David S; Falk, Kristen; Galiano, Lucía; Grünzweig, José M; Hartmann, Henrik; Hoch, Günter; Hood, Sharon; Jones, Joanna E; Koike, Takayoshi; Kuhlmann, Iris; Lloret, Francisco; Maestro, Melchor; Mansfield, Shawn D; Martínez-Vilalta, Jordi; Maucourt, Mickael; McDowell, Nathan G; Moing, Annick; Muller, Bertrand; Nebauer, Sergio G; Niinemets, Ülo; Palacio, Sara; Piper, Frida; Raveh, Eran; Richter, Andreas; Rolland, Gaëlle; Rosas, Teresa; Saint Joanis, Brigitte; Sala, Anna; Smith, Renee A; Sterck, Frank; Stinziano, Joseph R; Tobias, Mari; Unda, Faride; Watanabe, Makoto; Way, Danielle A; Weerasinghe, Lasantha K; Wild, Birgit; Wiley, Erin; Woodruff, David R

2015-11-01

Non-structural carbohydrates (NSC) in plant tissue are frequently quantified to make inferences about plant responses to environmental conditions. Laboratories publishing estimates of NSC of woody plants use many different methods to evaluate NSC. We asked whether NSC estimates in the recent literature could be quantitatively compared among studies. We also asked whether any differences among laboratories were related to the extraction and quantification methods used to determine starch and sugar concentrations. These questions were addressed by sending sub-samples collected from five woody plant tissues, which varied in NSC content and chemical composition, to 29 laboratories. Each laboratory analyzed the samples with their laboratory-specific protocols, based on recent publications, to determine concentrations of soluble sugars, starch and their sum, total NSC. Laboratory estimates differed substantially for all samples. For example, estimates for Eucalyptus globulus leaves (EGL) varied from 23 to 116 (mean = 56) mg g(-1) for soluble sugars, 6-533 (mean = 94) mg g(-1) for starch and 53-649 (mean = 153) mg g(-1) for total NSC. Mixed model analysis of variance showed that much of the variability among laboratories was unrelated to the categories we used for extraction and quantification methods (method category R(2) = 0.05-0.12 for soluble sugars, 0.10-0.33 for starch and 0.01-0.09 for total NSC). For EGL, the difference between the highest and lowest least squares means for categories in the mixed model analysis was 33 mg g(-1) for total NSC, compared with the range of laboratory estimates of 596 mg g(-1). Laboratories were reasonably consistent in their ranks of estimates among tissues for starch (r = 0.41-0.91), but less so for total NSC (r = 0.45-0.84) and soluble sugars (r = 0.11-0.83). Our results show that NSC estimates for woody plant tissues cannot be compared among laboratories. The relative changes in NSC between treatments measured within a laboratory

Intra-laboratory validation of microplate methods for total phenolic content and antioxidant activity on polyphenolic extracts, and comparison with conventional spectrophotometric methods.

PubMed

Bobo-García, Gloria; Davidov-Pardo, Gabriel; Arroqui, Cristina; Vírseda, Paloma; Marín-Arroyo, María R; Navarro, Montserrat

2015-01-01

Total phenolic content (TPC) and antioxidant activity (AA) assays in microplates save resources and time, therefore they can be useful to overcome the fact that the conventional methods are time-consuming, labour intensive and use large amounts of reagents. An intra-laboratory validation of the Folin-Ciocalteu microplate method to measure TPC and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) microplate method to measure AA was performed and compared with conventional spectrophotometric methods. To compare the TPC methods, the confidence intervals of a linear regression were used. In the range of 10-70 mg L(-1) of gallic acid equivalents (GAE), both methods were equivalent. To compare the AA methodologies, the F-test and t-test were used in a range from 220 to 320 µmol L(-1) of Trolox equivalents. Both methods had homogeneous variances, and the means were not significantively different. The limits of detection and quantification for the TPC microplate method were 0.74 and 2.24 mg L(-1) GAE and for the DPPH 12.07 and 36.58 µmol L(-1) of Trolox equivalents. The relative standard deviation of the repeatability and reproducibility for both microplate methods were ≤ 6.1%. The accuracy ranged from 88% to 100%. The microplate and the conventional methods are equals in a 95% confidence level. © 2014 Society of Chemical Industry.

Characterisation and monitoring of the Excavation Disturbed Zone (EDZ) in fractured gneisses of the Roselend underground laboratory: permeability measurements, transport property changes and related radon bursts

NASA Astrophysics Data System (ADS)

Wassermann, Jérôme; Sabroux, Jean-Christophe; Richon, Patrick; Pontreau, Sébastien; Guillon, Sophie; Pili, Eric

2010-05-01

The Roselend tunnel was drilled in the fifties by blasting in the micashists, granites and gneisses of the Méraillet massif (French Alps). It is situated on the shore of the Roselend reservoir Lake near its dam. Several tectonic shear fractures related to the Alpine orogeny intersect the dead end tunnel (with length of 128 m and section about 2 m), indeed the fracture density varies from 0.45 to 1 fracture per meter along the tunnel (Dezayes and Villemin 2002). Some fractures are partially or totally filled with secondary minerals. The flow rates of percolating water through the fractured medium are seasonal dependent. Large fractures drain a large fluid volume unlike small ones that drain limited fluid volume (Patriarche et al. 2007). The Roselend underground laboratory allows the study of the geochemical and geophysical responses of a fractured rock mass to periodic sollicitations due to water level variations of the nearby Roselend reservoir Lake. The tunnel was instrumented in the nineties to understand the relationship between radon (Rn-222) concentration and water level variations of the Roselend reservoir Lake (Trique et al. 1999). In order to characterize the geometry and the extent of the EDZ, core drilling and permeability measurements through pneumatic testing are performed along the Roselend tunnel. Drilled core analysis consists of direct observations at a macroscopic scale of fractures (density of fractures from EDZ) and also at a microscopic scale via thin sections. Method of pressure build-up in wells (Jakubick and Franz 1993, Bossart et al. 2002) is used to determine permeability profile along each borehole and hence to precise the extent and geometry of the EDZ. A strong correlation is observed between permeability profiles and the density of fractures estimated from core analysis. The extent of the EDZ appears to be about one tunnel radius i.e. one meter around the tunnel corridor. Another experiment consisting of continuous differential

Characterisation of titanium-titanium boride composites processed by powder metallurgy techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Selva Kumar, M., E-mail: sel_mcet@yahoo.co.in; Chandrasekar, P.; Chandramohan, P.

2012-11-15

In this work, a detailed characterisation of titanium-titanium boride composites processed by three powder metallurgy techniques, namely, hot isostatic pressing, spark plasma sintering and vacuum sintering, was conducted. Two composites with different volume percents of titanium boride reinforcement were used for the investigation. One was titanium with 20% titanium boride, and the other was titanium with 40% titanium boride (by volume). Characterisation was performed using X-ray diffraction, electron probe micro analysis - energy dispersive spectroscopy and wavelength dispersive spectroscopy, image analysis and scanning electron microscopy. The characterisation results confirm the completion of the titanium boride reaction. The results reveal themore » presence of titanium boride reinforcement in different morphologies such as needle-shaped whiskers, short agglomerated whiskers and fine plates. The paper also discusses how mechanical properties such as microhardness, elastic modulus and Poisson's ratio are influenced by the processing techniques as well as the volume fraction of the titanium boride reinforcement. - Highlights: Black-Right-Pointing-Pointer Ti-TiB composites were processed by HIP, SPS and vacuum sintering. Black-Right-Pointing-Pointer The completion of Ti-TiB{sub 2} reaction was confirmed by XRD, SEM and EPMA studies. Black-Right-Pointing-Pointer Hardness and elastic properties of Ti-TiB composites were discussed. Black-Right-Pointing-Pointer Processing techniques were compared with respect to their microstructure.« less

Identification and characterisation of isoprene-degrading bacteria in an estuarine environment.

PubMed

Johnston, Antonia; Crombie, Andrew T; El Khawand, Myriam; Sims, Leanne; Whited, Gregg M; McGenity, Terry J; Colin Murrell, J

2017-09-01

Approximately one-third of volatile organic compounds (VOCs) emitted to the atmosphere consists of isoprene, originating from the terrestrial and marine biosphere, with a profound effect on atmospheric chemistry. However, isoprene provides an abundant and largely unexplored source of carbon and energy for microbes. The potential for isoprene degradation in marine and estuarine samples from the Colne Estuary, UK, was investigated using DNA-Stable Isotope Probing (DNA-SIP). Analysis at two timepoints showed the development of communities dominated by Actinobacteria including members of the genera Mycobacterium, Rhodococcus, Microbacterium and Gordonia. Representative isolates, capable of growth on isoprene as sole carbon and energy source, were obtained from marine and estuarine locations, and isoprene-degrading strains of Gordonia and Mycobacterium were characterised physiologically and their genomes were sequenced. Genes predicted to be required for isoprene metabolism, including four-component isoprene monooxygenases (IsoMO), were identified and compared with previously characterised examples. Transcriptional and activity assays of strains growing on isoprene or alternative carbon sources showed that growth on isoprene is an inducible trait requiring a specific IsoMO. This study is the first to identify active isoprene degraders in estuarine and marine environments using DNA-SIP and to characterise marine isoprene-degrading bacteria at the physiological and molecular level. © 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

What do physicians tell laboratories when requesting tests? A multi-method examination of information supplied to the microbiology laboratory before and after the introduction of electronic ordering.

PubMed

Georgiou, Andrew; Prgomet, Mirela; Toouli, George; Callen, Joanne; Westbrook, Johanna

2011-09-01

The provision of relevant clinical information on pathology requests is an important part of facilitating appropriate laboratory utilization and accurate results interpretation and reporting. (1) To determine the quantity and importance of handwritten clinical information provided by physicians to the Microbiology Department of a hospital pathology service; and (2) to examine the impact of a Computerized Provider Order Entry (CPOE) system on the nature of clinical information communication to the laboratory. A multi-method and multi-stage investigation which included: (a) a retrospective audit of all handwritten Microbiology requests received over a 1-month period in the Microbiology Department of a large metropolitan teaching hospital; (b) the administration of a survey to laboratory professionals to investigate the impact of different clinical information on the processing and/or interpretation of tests; (c) an expert panel consisting of medical staff and senior scientists to assess the survey findings and their impact on pathology practice and patient care; and (d) a comparison of the provision and value of clinical information before CPOE, and across 3 years after its implementation. The audit of handwritten requests found that 43% (n=4215) contained patient-related clinical information. The laboratory survey showed that 97% (84/86) of the different types of clinical information provided for wound specimens and 86% (43/50) for stool specimens were shown to have an effect on the processing or interpretation of the specimens by one or more laboratory professionals. The evaluation of the impact of CPOE revealed a significant improvement in the provision of useful clinical information from 2005 to 2008, rising from 90.1% (n=749) to 99.8% (n=915) (p<.0001) for wound specimens and 34% (n=129) to 86% (n=422) (p<.0001) for stool specimens. This study showed that the CPOE system provided an integrated platform to access and exchange valuable patient-related information

Green synthesis and characterisation of platinum nanoparticles using quail egg yolk

NASA Astrophysics Data System (ADS)

Nadaroglu, Hayrunnisa; Gungor, Azize Alayli; Ince, Selvi; Babagil, Aynur

2017-02-01

Nanotechnology is extensively used in all parts today. Therefore, nano synthesis is also significant in all explored areas. The results of studies conducted have revealed that nanoparticle synthesis is performed by using both chemical and physical methods. It is well known that these syntheses are carried out at high charge, pressure and temperature in harsh environments. Therefore, this study investigated green synthesis method that sustains more mild conditions. In this study, quail egg yolk having high vitamin and protein content was prepared for green synthesis reaction and used for the synthesis of platinum nanoparticles in the reaction medium. Reaction situations were optimised as a function of pH, temperature, time and concentration by using quail egg yolk. The results showed that the highest platinum nanoparticles were synthesised at 20 °C and pH 6.0 for 4 h. Also, optimal concentration of metal ions was established as 0.5 mM. The synthesised platinum nanoparticles were characterised by using UV spectrum, X-ray diffraction and scanning electron microscope.

The contribution of the Florence Laboratory to the foundation of "scientific" psychology in Italy.

PubMed

Sava, Gabriella

2006-01-01

Studies of the history of Italian psychology have thoroughly and somewhat systematically analysed the particular characteristics and principal themes that distinguished this discipline in the period between the nineteenth and twentieth centuries. With regard to the affirmation of a "scientific" psychology in Italy, these studies have emphasized the importance of the research conducted at the University of Florence in the Laboratory of Experimental Psychology, founded in 1903 by Francesco De Sarlo. The results of the activity carried out in this laboratory are collected in the two volumes of Ricerche di Psicologia, published in 1905 and 1907. An analysis of these works clarifies the way in which De Sarlo and his collaborators intervened directly in the experimental activity. Various types of experimentation were conducted in the laboratory, such as those on the measurement of sensations and perceptions. The psychologists made use of adequate instruments, which they themselves often prepared or modified, without however neglecting an attentive survey of the states of consciousness. On the basis of a methodological approach that reconciles the accuracy of the measurements with the verification of the internal dimensions of the mental processes of the subjects undergoing the experimentation, the research carried out in the Florence Laboratory contributes to characterising, in an original way, the foundation of "scientific" psychology in Italy. In particular, by means of the publication of the results of this laboratory's research activity, Italian psychology acquired a new impulse to assert itself as an autonomous science and to promote its accreditation on an institutional level.

Prevention of infections in an ART laboratory: a reflection on simplistic methods.

PubMed

Huyser, C

2014-01-01

Preventative measures combined with reactive remedial actions are generic management tools to optimize and protect an entity's core businesses. Differences between assisted reproduction technology (ART) laboratories in developing versus developed countries include restricted access to, or availability of resources, and the prevalence of pathological conditions that are endemic or common in non-industrialized regions. The aim of this paper is to discuss the prevention of infections in an ART laboratory in a low to middle-income country, with reference to simplistic risk reduction applications to avoid the introduction and transmission of pathogens. Diagnostic and procedural phases will be examined, i.e. (i) screening for microbes during patient evaluation, and (ii-iii) prevention of environmental and procedural contamination. Preventative action is enabled by knowledge of threats and the degree of risk involved. Awareness and understanding of the vulnerabilities in an ART system, wherein laboratory personnel operate, are invaluable assets when unforeseen equipment failure occurs or instant decisions have to be made to safeguard procedures. An inter-connective team approach to patient treatment, biosafety training and utilization of practical procedures such as semen decontamination, are fundamental tools in a laboratory's risk-reduction armoury to prevent and eliminate infectious elements.

Characterising exoplanet atmospheres with SPHERE: the HR 8799 system with Exo-REM and NEMESIS

NASA Astrophysics Data System (ADS)

Baudino, J.-L.; Bonnefoy, M.; Vigan, A.; Irwin, P. J.

2017-12-01

The characterisation of the exoplanets evolved recently thanks to the beginning of the second generation of direct imaging instruments, especially with SPHERE. The resolution and wavelength range available currently give access to an increase of accuracy and on the number of physical parameters that can be constrain. One of the first target of SPHERE was the HR 8799 system. The four planets was characterised using four different forward models including Exo-REM. We complete this paper buy using NEMESIS, a retrieval code.

Sources, isolation, characterisation and evaluation of probiotics.

PubMed

Fontana, Luis; Bermudez-Brito, Miriam; Plaza-Diaz, Julio; Muñoz-Quezada, Sergio; Gil, Angel

2013-01-01

According to the FAO and the WHO, probiotics are 'live microorganisms which, when administered in adequate amounts, confer a health benefit on the host'. The strains most frequently used as probiotics include lactic acid bacteria and bifidobacteria, which are isolated from traditional fermented products and the gut, faeces and breast milk of human subjects. The identification of microorganisms is the first step in the selection of potential probiotics. The present techniques, including genetic fingerprinting, gene sequencing, oligonucleotide probes and specific primer selection, discriminate closely related bacteria with varying degrees of success. Additional molecular methods, such as denaturing gradient gel electrophoresis/temperature gradient gel electrophoresis and fluorescence in situ hybridisation, are employed to identify and characterise probiotics. The ability to examine fully sequenced genomes has accelerated the application of genetic approaches to the elucidation of the functional roles of probiotics. One of the best-demonstrated clinical benefits of probiotics is the prevention and treatment of acute and antibiotic-associated diarrhoea;however, there is mounting evidence for a potential role for probiotics in the treatment of allergies and intestinal, liver and metabolic diseases. There are various mechanisms by which probiotics exert their beneficial effects: regulation of intestinal permeability, normalisation of host intestinal microbiota, improvement of gut immune barrier function, and adjustment between pro- and anti-inflammatory cytokines. The number of studies carried out to test the effects of probiotics in vitro and in animals is enormous. However, the most reliable method of assessing the therapeutic benefits of any probiotic strain is the use of randomised, placebo-controlled trials, which are reviewed in this article [corrected].

Application of nanoparticle tracking analysis for characterising the fate of engineered nanoparticles in sediment-water systems.

PubMed

Luo, Ping; Roca, Alejandro; Tiede, Karen; Privett, Katie; Jiang, Jiachao; Pinkstone, John; Ma, Guibin; Veinot, Jonathan; Boxall, Alisatair

2018-02-01

Novel applications of nanotechnology may lead to the release of engineered nanoparticles (ENPs), which result in concerns over their potential environmental hazardous impact. It is essential for the research workers to be able to quantitatively characterise ENPs in the environment and subsequently to assist the risk assessment of the ENPs. This study hence explored the application of nanoparticle tracking system (NTA) to quantitatively describe the behaviour of the ENPs in natural sediment-water systems. The NTA allows the measurement of both particle number concentration (PNC) and particle size distribution (PSD) of the ENPs. The developed NTA method was applied to a range of gold and magnetite ENPs with a selection of surface properties. The results showed that the positively-charged ENPs interacted more strongly with the sediment than neutral and negatively-charged ENPs. It was also found that the citrate coated Au ENPs had a higher distribution percentage (53%) than 11-mercaptoundecanoic acid coated Au ENPs (20%) and citrate coated magnetite ENPs (21%). The principles of the electrostatic interactions between hard (and soft) acids and bases (HSAB) are used to explain such behaviours; the hard base coating (i.e. citrate ions) will interact more strongly with hard acid (i.e. magnetite) than soft acid (i.e. gold). The results indicate that NTA is a complementary method to existing approaches to characterise the fate and behaviour of ENPs in natural sediment. Copyright © 2017. Published by Elsevier B.V.

The Italian external quality assessment for RAS testing in colorectal carcinoma identifies methods-related inter-laboratory differences.

PubMed

Normanno, Nicola; Pinto, Carmine; Castiglione, Francesca; Fenizia, Francesca; Barberis, Massimo; Marchetti, Antonio; Fontanini, Gabriella; De Rosa, Gaetano; Taddei, Gian Luigi

2015-09-03

In 2014 the European Medicines Agency included exon 2, 3 and 4 KRAS and NRAS testing for the selection of metastatic colorectal cancer (mCRC) patients eligible for the therapy with anti-EGFR monoclonal antibodies. The Italian Association of Medical Oncology (AIOM) and the Italian Society of Pathology and Cytology (SIAPEC) organized an external quality assessment (EQA) scheme for CRC to evaluate inter-laboratory consistency and to ensure standardization of the results in the transition from KRAS to all-RAS testing. Ten formalin fixed paraffin embedded specimens including KRAS/NRAS (exons 2, 3, 4) and BRAF (codon 600) mutations were validated by three referral laboratories and sent to 88 participant centers. Molecular pathology sample reports were also requested to each laboratory. A board of assessors from AIOM and SIAPEC evaluated the results according to a predefined scoring system. The scheme was composed of two rounds. In the first round 36% of the 88 participants failed, with 23 centers having at least one false positive or false negative while 9 centers did not meet the deadline. The genotyping error rate was higher when Sanger sequencing was employed for testing as compared with pyrosequencing (3 vs 1.3%; p = 0.01; Pearson Chi Square test). In the second round, the laboratories improved their performance, with 23/32 laboratories passing the round. Overall, 79/88 participants passed the RAS EQA scheme. Standardized Human Genome Variation Society nomenclature was incorrectly used to describe the mutations identified and relevant variations were noticed in the genotype specification. The results of the Italian RAS EQA scheme indicate that the mutational analyses are performed with good quality in many Italian centers, although significant differences in the methods used were highlighted. The relatively high number of centers failing the first round underlines the fundamental role in continued education covered by EQA schemes.

Using 15N-Ammonium to Characterise and Map Potassium Binding Sites in Proteins by NMR Spectroscopy

PubMed Central

Werbeck, Nicolas D; Kirkpatrick, John; Reinstein, Jochen; Hansen, D Flemming

2014-01-01

A variety of enzymes are activated by the binding of potassium ions. The potassium binding sites of these enzymes are very specific, but ammonium ions can often replace potassium ions in vitro because of their similar ionic radii. In these cases, ammonium can be used as a proxy for potassium to characterise potassium binding sites in enzymes: the 1H,15N spin-pair of enzyme-bound 15NH4+ can be probed by 15N-edited heteronuclear NMR experiments. Here, we demonstrate the use of NMR spectroscopy to characterise binding of ammonium ions to two different enzymes: human histone deacetylase 8 (HDAC8), which is activated allosterically by potassium, and the bacterial Hsp70 homologue DnaK, for which potassium is an integral part of the active site. Ammonium activates both enzymes in a similar way to potassium, thus supporting this non-invasive approach. Furthermore, we present an approach to map the observed binding site onto the structure of HDAC8. Our method for mapping the binding site is general and does not require chemical shift assignment of the enzyme resonances. PMID:24520048

Drought characterisation based on an agriculture-oriented standardised precipitation index

NASA Astrophysics Data System (ADS)

Tigkas, Dimitris; Vangelis, Harris; Tsakiris, George

2018-03-01

Drought is a major natural hazard with significant effects in the agricultural sector, especially in arid and semi-arid regions. The accurate and timely characterisation of agricultural drought is crucial for devising contingency plans, including the necessary mitigation measures. Many drought indices have been developed during the last decades for drought characterisation and analysis. One of the most widely used indices worldwide is the Standardised Precipitation Index (SPI). Although other comprehensive indices have been introduced over the years, SPI remains the most broadly accepted index due to a number of reasons, the most important of which are its simple structure and the fact that it uses only precipitation data. In this paper, a modified version of SPI is proposed, namely the Agricultural Standardised Precipitation Index (aSPI), based on the substitution of the total precipitation by the effective precipitation, which describes more accurately the amount of water that can be used productively by the plants. Further, the selection of the most suitable reference periods and time steps for agricultural drought identification using aSPI is discussed. This conceptual enhancement of SPI aims at improving the suitability of the index for agricultural drought characterisation, while retaining the advantages of the original index, including its dependence only on precipitation data. The evaluation of the performance of both SPI and aSPI in terms of correlating drought magnitude with crop yield response in four regions of Greece under Mediterranean conditions indicated that aSPI is more robust than the original index in identifying agricultural drought.

10 CFR 431.18 - Testing laboratories.

Code of Federal Regulations, 2010 CFR

2010-01-01

... EQUIPMENT Electric Motors Test Procedures, Materials Incorporated and Methods of Determining Efficiency... Technology/National Voluntary Laboratory Accreditation Program (NIST/NVLAP); or (2) A laboratory... of the National Institute of Standards and Technology (NIST) which is part of the U.S. Department of...

Characterisation of ATM mutations in Slavic Ataxia telangiectasia patients.

PubMed

Soukupova, Jana; Pohlreich, Petr; Seemanova, Eva

2011-09-01

Ataxia telangiectasia (AT) is a genomic instability syndrome characterised, among others, by progressive cerebellar degeneration, oculocutaneous telangiectases, immunodeficiency, elevated serum alpha-phetoprotein level, chromosomal breakage, hypersensitivity to ionising radiation and increased cancer risk. This autosomal recessive disorder is caused by mutations in the ataxia telangiectasia mutated (ATM) gene coding for serine/threonine protein kinase with a crucial role in response to DNA double-strand breaks. We characterised genotype and phenotype of 12 Slavic AT patients from 11 families. Mutation analysis included sequencing of the entire coding sequence, adjacent intron regions, 3'UTR and 5'UTR of the ATM gene and multiplex ligation-dependent probe amplification (MLPA) for the detection of large deletions/duplications at the ATM locus. The high incidence of new and individual mutations demonstrates a marked mutational heterogeneity of AT in the Czech Republic. Our data indicate that sequence analysis of the entire coding region of ATM is sufficient for a high detection rate of mutations in ATM and that MLPA analysis for the detection of deletions/duplications seems to be redundant in the Slavic population.

Characterisation and modelling of defect formation in direct-chill cast AZ80 alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mackie, D.; Robson, J.D.; Withers, P.J.

2015-06-15

Wrought magnesium alloys for demanding structural applications require high quality defect free cast feedstock. The aim of this study was to first identify and characterise typical defects in direct chill cast magnesium–aluminium–zinc (AZ) alloy billet and then use modelling to understand the origins of these defects so they can be prevented. Defects were first located using ultrasonic inspection and were then characterised using X-ray computed tomography (XCT) and serial sectioning, establishing the presence of oxide films and intermetallic particles Al{sub 8}Mn{sub 5} in all defects. A model was developed to predict the flow patterns and growth kinetics of the intermetallicmore » phases during casting, which influence the formation of defects. Simulation of the growth of the intermetallic particles demonstrated that precipitation from the liquid occurs in the mould. The combination of the entrained oxide films and intermetallic particles recirculates in the liquid metal and continues to grow, until large enough to settle, which is predicted to occur at the centre of the mould where the flow is the slowest. Based on these predictions, strategies to reduce the susceptibility to defect formation are suggested. - Highlights: • Casting defects in magnesium direct chill casting have been imaged and characterised in 3-dimensions. • The occurrences of co-located clusters of particles and oxide films have been characterised and explained. • A coupled model has been developed to help interpret the observed trend for defects located towards the centre of billets.« less

Laboratory 3.0: Manufacturing Technologies Laboratory Virtualization with a Student-Centred Methodology

ERIC Educational Resources Information Center

Fabregat-Sanjuan, Albert; Pàmies-Vilà, Rosa; Ferrando Piera, Francesc; De la Flor López, Silvia

2017-01-01

This paper presents a blended-learning strategy for improving the teaching method applied in the laboratory subject Manufacturing Technologies. The teaching method has been changed from a predominantly teacher-centred to an active learning system with a student-centred focus and e-learning activities. In face-to-face classes, a game-based learning…

[ISO 15189 medical laboratory accreditation].

PubMed

Aoyagi, Tsutomu

2004-10-01

This International Standard, based upon ISO/IEC 17025 and ISO 9001, provides requirements for competence and quality that are particular to medical laboratories. While this International Standard is intended for use throughout the currently recognized disciplines of medical laboratory services, those working in other services and disciplines will also find it useful and appropriate. In addition, bodies engaged in the recognition of the competence of medical laboratories will be able to use this International Standard as the basis for their activities. The Japan Accreditation Board for Conformity Assessment (AB) and the Japanese Committee for Clinical Laboratory Standards (CCLS) are jointly developing the program of accreditation of medical laboratories. ISO 15189 requirements consist of two parts, one is management requirements and the other is technical requirements. The former includes the requirements of all parts of ISO 9001, moreover it includes the requirement of conformity assessment body, for example, impartiality and independence from any other party. The latter includes the requirements of laboratory competence (e.g. personnel, facility, instrument, and examination methods), moreover it requires that laboratories shall participate proficiency testing(s) and laboratories' examination results shall have traceability of measurements and implement uncertainty of measurement. Implementation of ISO 15189 will result in a significant improvement in medical laboratories management system and their technical competence. The accreditation of medical laboratory will improve medical laboratory service and be useful for patients.

Methods for using clinical laboratory test results as baseline confounders in multi-site observational database studies when missing data are expected.

PubMed

Raebel, Marsha A; Shetterly, Susan; Lu, Christine Y; Flory, James; Gagne, Joshua J; Harrell, Frank E; Haynes, Kevin; Herrinton, Lisa J; Patorno, Elisabetta; Popovic, Jennifer; Selvan, Mano; Shoaibi, Azadeh; Wang, Xingmei; Roy, Jason

2016-07-01

Our purpose was to quantify missing baseline laboratory results, assess predictors of missingness, and examine performance of missing data methods. Using the Mini-Sentinel Distributed Database from three sites, we selected three exposure-outcome scenarios with laboratory results as baseline confounders. We compared hazard ratios (HRs) or risk differences (RDs) and 95% confidence intervals (CIs) from models that omitted laboratory results, included only available results (complete cases), and included results after applying missing data methods (multiple imputation [MI] regression, MI predictive mean matching [PMM] indicator). Scenario 1 considered glucose among second-generation antipsychotic users and diabetes. Across sites, glucose was available for 27.7-58.9%. Results differed between complete case and missing data models (e.g., olanzapine: HR 0.92 [CI 0.73, 1.12] vs 1.02 [0.90, 1.16]). Across-site models employing different MI approaches provided similar HR and CI; site-specific models provided differing estimates. Scenario 2 evaluated creatinine among individuals starting high versus low dose lisinopril and hyperkalemia. Creatinine availability: 44.5-79.0%. Results differed between complete case and missing data models (e.g., HR 0.84 [CI 0.77, 0.92] vs. 0.88 [0.83, 0.94]). HR and CI were identical across MI methods. Scenario 3 examined international normalized ratio (INR) among warfarin users starting interacting versus noninteracting antimicrobials and bleeding. INR availability: 20.0-92.9%. Results differed between ignoring INR versus including INR using missing data methods (e.g., RD 0.05 [CI -0.03, 0.13] vs 0.09 [0.00, 0.18]). Indicator and PMM methods gave similar estimates. Multi-site studies must consider site variability in missing data. Different missing data methods performed similarly. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Quantification of histochemical stains using whole slide imaging: development of a method and demonstration of its usefulness in laboratory quality control.

PubMed

Gray, Allan; Wright, Alex; Jackson, Pete; Hale, Mike; Treanor, Darren

2015-03-01

Histochemical staining of tissue is a fundamental technique in tissue diagnosis and research, but it suffers from significant variability. Efforts to address this include laboratory quality controls and quality assurance schemes, but these rely on subjective interpretation of stain quality, are laborious and have low reproducibility. We aimed (1) to develop a method for histochemical stain quantification using whole slide imaging and image analysis and (2) to demonstrate its usefulness in measuring staining variation. A method to quantify the individual stain components of histochemical stains on virtual slides was developed. It was evaluated for repeatability and reproducibility, then applied to control sections of an appendix to quantify H&E staining (H/E intensities and H:E ratio) between automated staining machines and to measure differences between six regional diagnostic laboratories. The method was validated with <0.5% variation in H:E ratio measurement when using the same scanner for a batch of slides (ie, it was repeatable) but was not highly reproducible between scanners or over time, where variation of 7% was found. Application of the method showed H:E ratios between three staining machines varied from 0.69 to 0.93, H:E ratio variation over time was observed. Interlaboratory comparison demonstrated differences in H:E ratio between regional laboratories from 0.57 to 0.89. A simple method using whole slide imaging can be used to quantify and compare histochemical staining. This method could be deployed in routine quality assurance and quality control. Work is needed on whole slide imaging devices to improve reproducibility. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Health Behaviour Change Through Computer Games: Characterising Interventions.

PubMed

Poultney, Nathan; Maeder, Anthony; Ginige, Jeewani Anupama

2016-01-01

Recently games in the form of video, computer, or mobile apps have been utilised as an effective component of interventions for health behaviour change. This paper provides an overview of related projects reported in peer-review literature in the period 2006 to 2016. Nine highly relevant references were considered for analysis. The findings are presented according to 3 dimensions of characterisation: health intention, behaviour change principle, and health purpose.

National survey on intra-laboratory turnaround time for some most common routine and stat laboratory analyses in 479 laboratories in China

PubMed Central

Fei, Yang; Zeng, Rong; Wang, Wei; He, Falin; Zhong, Kun

2015-01-01

Introduction To investigate the state of the art of intra-laboratory turnaround time (intra-TAT), provide suggestions and find out whether laboratories accredited by International Organization for Standardization (ISO) 15189 or College of American Pathologists (CAP) will show better performance on intra-TAT than non-accredited ones. Materials and methods 479 Chinese clinical laboratories participating in the external quality assessment programs of chemistry, blood gas, and haematology tests organized by the National Centre for Clinical Laboratories in China were included in our study. General information and the median of intra-TAT of routine and stat tests in last one week were asked in the questionnaires. Results The response rate of clinical biochemistry, blood gas, and haematology testing were 36% (479 / 1307), 38% (228 / 598), and 36% (449 / 1250), respectively. More than 50% of laboratories indicated that they had set up intra-TAT median goals and almost 60% of laboratories declared they had monitored intra-TAT generally for every analyte they performed. Among all analytes we investigated, the intra-TAT of haematology analytes was shorter than biochemistry while the intra-TAT of blood gas analytes was the shortest. There were significant differences between median intra-TAT on different days of the week for routine tests. However, there were no significant differences in median intra-TAT reported by accredited laboratories and non-accredited laboratories. Conclusions Many laboratories in China are aware of intra-TAT control and are making effort to reach the target. There is still space for improvement. Accredited laboratories have better status on intra-TAT monitoring and target setting than the non-accredited, but there are no significant differences in median intra-TAT reported by them. PMID:26110033

A professional development model for medical laboratory scientists working in the immunohematology laboratory.

PubMed

Garza, Melinda N; Pulido, Lila A; Amerson, Megan; Ali, Faheem A; Greenhill, Brandy A; Griffin, Gary; Alvarez, Enrique; Whatley, Marsha; Hu, Peter C

2012-01-01

Transfusion medicine, a section of the Department of Laboratory Medicine at The University of Texas MD Anderson Cancer Center is committed to the education and advancement of its health care professionals. It is our belief that giving medical laboratory professionals a path for advancement leads to excellence and increases overall professionalism in the Immunohematology Laboratory. As a result of this strong commitment to excellence and professionalism, the Immunohematology laboratory has instituted a Professional Development Model (PDM) that aims to create Medical Laboratory Scientists (MLS) that are not only more knowledgeable, but are continually striving for excellence. In addition, these MLS are poised for advancement in their careers. The professional development model consists of four levels: Discovery, Application, Maturation, and Expert. The model was formulated to serve as a detailed path to the mastery of all process and methods in the Immunohematology Laboratory. Each level in the professional development model consists of tasks that optimize the laboratory workflow and allow for concurrent training. Completion of a level in the PDM is rewarded with financial incentive and further advancement in the field. The PDM for Medical Laboratory Scientists in the Immunohematology Laboratory fosters personal development, rewards growth and competency, and sets high standards for all services and skills provided. This model is a vital component of the Immunohematology Laboratory and aims to ensure the highest quality of care and standards in their testing. It is because of the success of this model and the robustness of its content that we hope other medical laboratories aim to reach the same level of excellence and professionalism, and adapt this model into their own environment.

Characterisation and quantification of groundwater-surface water interactions along an alluvial stream using geophysical, hydraulic and tracer methods

NASA Astrophysics Data System (ADS)

Rumph Frederiksen, R.; Rasmussen, K. R.; Christensen, S.

2015-12-01

Qualifying and quantifying water, nutrient and contaminant exchange at the groundwater-surface water interface are becoming increasingly important for water resources management. The objectives of this study are to characterise an alluvial stream using geophysics in addition to traditional geological and geomorphological data and quantify the groundwater seepage to the stream on point-to-reach scale using both hydraulic and tracer methods. We mapped the very shallow subsurface along an alluvial stream using a GCM system (DUALEM421S, an electromagnetic system that can be operated behind a boat or towed behind a motorized vehicle) as well as using geological logs from a large number of old wells. Furthermore we made geomorphological observations through digital maps (old topographical maps and aerial photos) and field observations. We measured stream discharge (quasi-) simultaneously at several positions along the stream using both an Ott-C31 propeller instrument and an Acoustic Doppler Current Profiler instrument. The measurements were made during dry summer periods when baseflow is expected to be the dominating contribution to streamflow. Preliminary findings show that the GCM system reveals small-scale structures not seen with other data types. Furthermore, based on the GCM results and stream discharge results we have identified gaining, losing and zero exchange sections of the stream. During late summer 2015 we will collect additional hydrological data in order to support or modify our preliminary findings. To further investigate the spatial and temporal variations of the groundwater-surface water interactions along the stream we will measure groundwater seepage to the stream using: seepage meter (point-scale) DTS (reach-scale) temperature stick measurements (point-in-space-and-time-scale) temperature loggers installed in the streambed (month-scale) The measurement sites are chosen based on our geophysical, geological, and geomorphological mapping as well as our

Pervasive randomness in physics: an introduction to its modelling and spectral characterisation

NASA Astrophysics Data System (ADS)

Howard, Roy

2017-10-01

An introduction to the modelling and spectral characterisation of random phenomena is detailed at a level consistent with a first exposure to the subject at an undergraduate level. A signal framework for defining a random process is provided and this underpins an introduction to common random processes including the Poisson point process, the random walk, the random telegraph signal, shot noise, information signalling random processes, jittered pulse trains, birth-death random processes and Markov chains. An introduction to the spectral characterisation of signals and random processes, via either an energy spectral density or a power spectral density, is detailed. The important case of defining a white noise random process concludes the paper.

Characterisation and Antioxidant Activity of Crude Extract and Polyphenolic Rich Fractions from C. incanus Leaves

PubMed Central

Gori, Antonella; Ferrini, Francesco; Marzano, Maria Cristina; Tattini, Massimiliano; Centritto, Mauro; Baratto, Maria Camilla; Pogni, Rebecca; Brunetti, Cecilia

2016-01-01

Cistus incanus (Cistaceae) is a Mediterranean evergreen shrub. Cistus incanus herbal teas have been used as a general remedy in traditional medicine since ancient times. Recent studies on the antioxidant properties of its aqueous extracts have indicated polyphenols to be the most active compounds. However, a whole chemical characterisation of polyphenolic compounds in leaves of Cistus incanus (C. incanus) is still lacking. Moreover, limited data is available on the contribution of different polyphenolic compounds towards the total antioxidant capacity of its extracts. The purpose of this study was to characterise the major polyphenolic compounds present in a crude ethanolic leaf extract (CEE) of C. incanus and develop a method for their fractionation. Superoxide anion, hydroxyl and DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging assays were also performed to evaluate the antioxidant properties of the obtained fractions. Three different polyphenolic enriched extracts, namely EAC (Ethyl Acetate Fraction), AF1 and AF2 (Aqueos Fractions), were obtained from CEE. Our results indicated that the EAC, enriched in flavonols, exhibited a higher antiradical activity compared to the tannin enriched fractions (AF1 and AF2). These findings provide new perspectives for the use of the EAC as a source of antioxidant compounds with potential uses in pharmaceutical preparations. PMID:27548139

Characterisation of electrical resistance for CMC Materials up to 1200 °C

NASA Astrophysics Data System (ADS)

Stäbler, T.; Böhrk, H.; Voggenreiter, H.

2017-12-01

Damage to thermal protection systems (TPS) during atmospheric re-entry is a severe safety issue, especially when considering re-usability of space transportation systems. There is a need for structural health monitoring systems and non-destructive inspection methods. However, damages are hard to detect. When ceramic matrix composites, in this case carbon fibre reinforced silicon carbide (C/C-SiC), are used as a TPS, the electrical properties of the present semiconductor material can be used for health monitoring, since the resistivity changes with damage, strain and temperature. In this work the electrical resistivity as a function of the material temperature is analysed eliminating effects of thermal electricity and the thermal coefficient of electrical resistance is determined. A sensor network is applied for locally and time resolved monitoring of the 300 mm x 120 mm x 3 mm panel shaped samples. Since the material is used for atmospheric re-entry it needs to be characterised for a wide range of temperatures, in this case as high as 1200 °C. Therefore, experiments in an inductively heated test bench were conducted. Firstly, a reference sample was used with thermocouples for characterising the temperature distribution across the sample surface. Secondly, electrical resistance under heat load was measured, time and spatially resolved. Results will be shown and discussed in terms of resistance dependence on temperature, thermal coefficient of electrical resistance, thermal electricity and electrical path orientation including an analysis on effective conducting cross section. Conversely, the thermal coefficient can also be used to determine the material temperature as a function of electrical resistance.

The Effect of Jigsaw Technique on the Students' Laboratory Material Recognition and Usage Skills in General Physics Laboratory-I Course

ERIC Educational Resources Information Center

Aydin, Abdullah; Biyikli, Filiz

2017-01-01

This research aims to compare the effects of Jigsaw technique from the cooperative learning methods and traditional learning method on laboratory material recognition and usage skills of students in General Physics Lab-I Course. This study was conducted with 63 students who took general physics laboratory-I course in the department of science…

Mass spectrometric characterisation of a condensation product between porphobilinogen and indolyl-3-acryloylglycine in urine of patients with acute intermittent porphyria.

PubMed

Marcos, Josep; Ibañez, Maria; Ventura, Rosa; Segura, Jordi; To-Figueras, Jordi; Pozo, Oscar J

2015-07-01

We document the presence of a previously unknown species in the urine of patients with acute intermittent porphyria (AIP). The compound was fully characterised by liquid chromatography tandem mass spectrometry. Interpretation of both full spectrum acquisition and product ion spectra acquired in positive and negative ionisation modes by quadrupole time of flight MS allowed for the identification of a condensation product arising from porphobilinogen (PBG, increased in the urine of AIP patients) and indolyl-3-acryloylglycine (IAG, derived from indolylacrylic acid and present in human urine). The structure was unequivocally confirmed through comparison between the selected reaction monitoring chromatograms obtained from the urinary species and the condensation product qualitatively synthesised in the laboratory. Owing to the large amounts of both PBG and IAG in urine of AIP patients, the possible ex vivo formation of PBG-IAG in urine samples was evaluated. The product was spontaneously formed at room temperature, at 4 °C and even during storage at -20 °C when spiking a control sample with PBG. A positive correlation was found between PBG and PBG-IAG in samples collected from AIP patients. However, no correlation was found between PBG-IAG and IAG. Purified PBG-IAG did not form the characteristic chromogen after application of p-dimethylaminobenzaldehyde in HCl, thus suggesting that the current techniques used to measure PBG in urine of AIP patients based on Ehlrich's reaction do not detect this newly characterised PBG-IAG fraction. Copyright © 2015 John Wiley & Sons, Ltd.

Ground Penetrating Radar as a Contextual Sensor for Multi-Sensor Radiological Characterisation

PubMed Central

Ukaegbu, Ikechukwu K.; Gamage, Kelum A. A.

2017-01-01

Radioactive sources exist in environments or contexts that influence how they are detected and localised. For instance, the context of a moving source is different from a stationary source because of the effects of motion. The need to incorporate this contextual information in the radiation detection and localisation process has necessitated the integration of radiological and contextual sensors. The benefits of the successful integration of both types of sensors is well known and widely reported in fields such as medical imaging. However, the integration of both types of sensors has also led to innovative solutions to challenges in characterising radioactive sources in non-medical applications. This paper presents a review of such recent applications. It also identifies that these applications mostly use visual sensors as contextual sensors for characterising radiation sources. However, visual sensors cannot retrieve contextual information about radioactive wastes located in opaque environments encountered at nuclear sites, e.g., underground contamination. Consequently, this paper also examines ground-penetrating radar (GPR) as a contextual sensor for characterising this category of wastes and proposes several ways of integrating data from GPR and radiological sensors. Finally, it demonstrates combined GPR and radiation imaging for three-dimensional localisation of contamination in underground pipes using radiation transport and GPR simulations. PMID:28387706

Sheet metals characterization using the virtual fields method

NASA Astrophysics Data System (ADS)

Marek, Aleksander; Davis, Frances M.; Pierron, Fabrice

2018-05-01

In this work, a characterisation method involving a deep-notched specimen subjected to a tensile loading is introduced. This specimen leads to heterogeneous states of stress and strain, the latter being measured using a stereo DIC system (MatchID). This heterogeneity enables the identification of multiple material parameters in a single test. In order to identify material parameters from the DIC data, an inverse method called the Virtual Fields Method is employed. The method combined with recently developed sensitivity-based virtual fields allows to optimally locate areas in the test where information about each material parameter is encoded, improving accuracy of the identification over the traditional user-defined virtual fields. It is shown that a single test performed at 45° to the rolling direction is sufficient to obtain all anisotropic plastic parameters, thus reducing experimental effort involved in characterisation. The paper presents the methodology and some numerical validation.

Laboratory issues: use of nutritional biomarkers.

PubMed

Blanck, Heidi Michels; Bowman, Barbara A; Cooper, Gerald R; Myers, Gary L; Miller, Dayton T

2003-03-01

Biomarkers of nutritional status provide alternative measures of dietary intake. Like the error and variation associated with dietary intake measures, the magnitude and impact of both biological (preanalytical) and laboratory (analytical) variability need to be considered when one is using biomarkers. When choosing a biomarker, it is important to understand how it relates to nutritional intake and the specific time frame of exposure it reflects as well as how it is affected by sampling and laboratory procedures. Biological sources of variation that arise from genetic and disease states of an individual affect biomarkers, but they are also affected by nonbiological sources of variation arising from specimen collection and storage, seasonality, time of day, contamination, stability and laboratory quality assurance. When choosing a laboratory for biomarker assessment, researchers should try to make sure random and systematic error is minimized by inclusion of certain techniques such as blinding of laboratory staff to disease status and including external pooled standards to which laboratory staff are blinded. In addition analytic quality control should be ensured by use of internal standards or certified materials over the entire range of possible values to control method accuracy. One must consider the effect of random laboratory error on measurement precision and also understand the method's limit of detection and the laboratory cutpoints. Choosing appropriate cutpoints and reducing error is extremely important in nutritional epidemiology where weak associations are frequent. As part of this review, serum lipids are included as an example of a biomarker whereby collaborative efforts have been put forth to both understand biological sources of variation and standardize laboratory results.

Valorisation of chicken feathers: Characterisation of chemical properties.

PubMed

Tesfaye, Tamrat; Sithole, Bruce; Ramjugernath, Deresh; Chunilall, Viren

2017-10-01

The characterisation of the chemical properties of the whole chicken feather and its fractions (barb and rachis), was undertaken to identify opportunities for valorizing this waste product. The authors have described the physical, morphological, mechanical, electrical and thermal properties of the chicken feathers and related them to potential valorisation routes of the waste. However, identification of their chemical properties is necessary to complete a comprehensive description of chicken feather fractions. Hence, the chicken feathers were thoroughly characterised by proximate and ultimate analyses, elemental composition, spectroscopic analyses, durability in different solvents, burning test, and hydrophobicity. The proximate analysis of chicken feathers revealed the following compositions: crude lipid (0.83%), crude fibre (2.15%), crude protein (82.36%), ash (1.49%), NFE (1.02%) and moisture content (12.33%) whereas the ultimate analyses showed: carbon (64.47%), nitrogen (10.41%), oxygen (22.34%), and sulphur (2.64%). FTIR analysis revealed that the chicken feather fractions contain amide and carboxylic groups indicative of proteinious functional groups; XRD showed a crystallinity index of 22. Durability and burning tests confirmed that feathers behaved similarly to animal fibre. This reveals that chicken feather can be a valuable raw material in textile, plastic, cosmetics, pharmaceuticals, biomedical and bioenergy industries. Copyright © 2017 Elsevier Ltd. All rights reserved.

A transient laboratory method for determining the hydraulic properties of 'tight' rocks-I. Theory

USGS Publications Warehouse

Hsieh, P.A.; Tracy, J.V.; Neuzil, C.E.; Bredehoeft, J.D.; Silliman, Stephen E.

1981-01-01

Transient pulse testing has been employed increasingly in the laboratory to measure the hydraulic properties of rock samples with low permeability. Several investigators have proposed a mathematical model in terms of an initial-boundary value problem to describe fluid flow in a transient pulse test. However, the solution of this problem has not been available. In analyzing data from the transient pulse test, previous investigators have either employed analytical solutions that are derived with the use of additional, restrictive assumptions, or have resorted to numerical methods. In Part I of this paper, a general, analytical solution for the transient pulse test is presented. This solution is graphically illustrated by plots of dimensionless variables for several cases of interest. The solution is shown to contain, as limiting cases, the more restrictive analytical solutions that the previous investigators have derived. A method of computing both the permeability and specific storage of the test sample from experimental data will be presented in Part II. ?? 1981.

Rapid Methods for the Laboratory Identification of Pathogenic Microorganisms.

DTIC Science & Technology

1982-09-01

for the use of plant proteins, called lectins, in diagnostic microbiology. We studied lectin interactions with Staphylococcus, Legionella, Streptococcus ...commercial sources (BBL and Difco). Thethree Brucella species: suis abortus, and melitensis were also purchased from BBL and Difco. Lectins were obtained...that are killed by antibiotic treatment rather than formalin. Lee Laboratories in Georgia has offered to prepare these antigens for us according to our

Toxicological methods for tracing drug abuse: chromatographic, spectroscopic and biological characterisation of ecstasy derivatives.

PubMed

Belhadj-Tahar, Hafid; Payoux, Pierre; Tafani, Mathieu; Coulais, Yvon; Calet, Serge; Bousseksou, Azzedine

2010-03-01

Analysis often reveals variability in the composition of ecstasy pills from pure 3,4-methylenedioxymethamphetamine (MDMA) to mixtures of MDMA derivatives, amphetamine, and other unidentified substances. For a comprehensive toxicological analysis one needs to know all steps to MDMA synthesis which may originate impurities. The aim of this study was to synthesise and determine the chemical-physical and in vitro biological properties of a series of MDMA derivatives.3,4-methylendioxyphenyl-2-nitropropene (MDNP) was obtained by condensation of piperonal with an excess of nitroethane in the presence of ammonium acetate. MDNP was then reduced to methylenedioxyamphetamine (MDA) by LiAlH3. All compounds were analysed using HPLC and spectroscopic technique [Raman, nuclear magnetic resonance (NMR), or infrared (IR)] at all the steps of synthesis. In addition, we assessed the biological potentials of these compounds by measuring in vitro their (i) blood cell/whole blood partition coefficient, (ii) binding to plasmatic proteins (Fbp), and (iii) membrane adsorption. Chemical structure was determined with antibody fluorescence polarisation immunoassay (FPIA). This study showed the presence of solid impurities, particularly of a neurotoxic compound of Al3+ in the final products. FPIA identified the aminoethane group close to the substituted benzene ring, but did not detect the two major precursors of MDMA: MDNP and piperonal. Raman spectroscopy is an attractive alternative technique to characterise ecstasy pills and it can identify stereoisomeric forms such as cis-MDNP and trans-MDNP, which exhibit signals at 1650 cm-1 and 1300 cm-1, respectively.

Characterisation of Fine Ash Fractions from the AD 1314 Kaharoa Eruption

NASA Astrophysics Data System (ADS)

Weaver, S. J.; Rust, A.; Carey, R. J.; Houghton, B. F.

2012-12-01

The AD 1314±12 yr Kaharoa eruption of Tarawera volcano, New Zealand, produced deposits exhibiting both plinian and subplinian characteristics (Nairn et al., 2001; 2004, Leonard et al., 2002, Hogg et al., 2003). Their widespread dispersal yielded volumes, column heights, and mass discharge rates of plinian magnitude and intensity (Sahetapy-Engel, 2002); however, vertical shifts in grain size suggest waxing and waning within single phases and time-breaks on the order of hours between phases. These grain size shifts were quantified using sieve, laser diffraction, and image analysis of the fine ash fractions (<1 mm in diameter) of some of the most explosive phases of the eruption. These analyses served two purposes: 1) to characterise the change in eruption intensity over time, and 2) to compare the three methods of grain size analysis. Additional analyses of the proportions of components and particle shape were also conducted to aid in the interpretation of the eruption and transport dynamics. 110 samples from a single location about 6 km from source were sieved at half phi intervals between -4φ to 4φ (16 mm - 63 μm). A single sample was then chosen to test the range of grain sizes to run through the Mastersizer 2000. Three aliquots were tested; the first consisted of each sieve size fraction ranging between 0φ (1000 μm) and <4φ (<63 μm, i.e. the pan). For example, 0, 0.5, 1, …, 4φ, and the pan were ran through the Mastersizer and then their results, weighted according to their sieve weight percents, were summed together to produce a total distribution. The second aliquot included 3 samples ranging between 0-2φ (1000-250 μm), 2.5-4φ (249-63 μm), and the pan. A single sample consisting of the total range of grain sizes between 0φ and the pan was used for the final aliquot. Their results were compared and it was determined that the single sample consisting of the broadest range of grain sizes yielded an accurate grain size distribution. This data was

Indoor Air Quality in Chemistry Laboratories.

ERIC Educational Resources Information Center

Hays, Steve M.

This paper presents air quality and ventilation data from an existing chemical laboratory facility and discusses the work practice changes implemented in response to deficiencies in ventilation. General methods for improving air quality in existing laboratories are presented and investigation techniques for characterizing air quality are…

Multi-pelvis characterisation of articular cartilage geometry.

PubMed

Gillard, Faye C; Dickinson, Alexander S; Schneider, Urs; Taylor, Andrew C; Browne, Martin

2013-12-01

The shape of the acetabular cartilage follows the contact stress distribution across the joint. Accurate characterisation of this geometry may be useful for the development of acetabular cup devices that are more biomechanically compliant. In this study, the geometry of the acetabular cartilage was characterised by taking plaster moulds of the acetabulum from 24 dry bone human pelvises and digitising the mould shapes using a three-dimensional laser scanner. The articular bone surface geometry was analysed, and the shape of the acetabulum was approximated by fitting a best-fit sphere. To test the hypothesis that the acetabulum is non-spherical, a best-fit ellipsoid was also fitted to the geometry. In each case, points around the acetabular notch edge that disclosed the articular surface geometry were identified, and vectors were drawn between these and the best-fit sphere or ellipsoid centre. The significantly larger z radii (into the pole) of the ellipsoids indicated that the acetabulum was non-spherical and could imply that the kinematics of the hip joint is more complex than purely rotational motion, and the traditional ball-and-socket replacement may need to be updated to reflect this motion. The acetabular notch edges were observed to be curved, with males exhibiting deeper, wider and shorter notches than females, although the difference was not statistically significant (mean: p = 0.30) and supports the use of non-gender-specific models in anatomical studies.

A normalization method for combination of laboratory test results from different electronic healthcare databases in a distributed research network.

PubMed

Yoon, Dukyong; Schuemie, Martijn J; Kim, Ju Han; Kim, Dong Ki; Park, Man Young; Ahn, Eun Kyoung; Jung, Eun-Young; Park, Dong Kyun; Cho, Soo Yeon; Shin, Dahye; Hwang, Yeonsoo; Park, Rae Woong

2016-03-01

Distributed research networks (DRNs) afford statistical power by integrating observational data from multiple partners for retrospective studies. However, laboratory test results across care sites are derived using different assays from varying patient populations, making it difficult to simply combine data for analysis. Additionally, existing normalization methods are not suitable for retrospective studies. We normalized laboratory results from different data sources by adjusting for heterogeneous clinico-epidemiologic characteristics of the data and called this the subgroup-adjusted normalization (SAN) method. Subgroup-adjusted normalization renders the means and standard deviations of distributions identical under population structure-adjusted conditions. To evaluate its performance, we compared SAN with existing methods for simulated and real datasets consisting of blood urea nitrogen, serum creatinine, hematocrit, hemoglobin, serum potassium, and total bilirubin. Various clinico-epidemiologic characteristics can be applied together in SAN. For simplicity of comparison, age and gender were used to adjust population heterogeneity in this study. In simulations, SAN had the lowest standardized difference in means (SDM) and Kolmogorov-Smirnov values for all tests (p < 0.05). In a real dataset, SAN had the lowest SDM and Kolmogorov-Smirnov values for blood urea nitrogen, hematocrit, hemoglobin, and serum potassium, and the lowest SDM for serum creatinine (p < 0.05). Subgroup-adjusted normalization performed better than normalization using other methods. The SAN method is applicable in a DRN environment and should facilitate analysis of data integrated across DRN partners for retrospective observational studies. Copyright © 2015 John Wiley & Sons, Ltd.

Copper resinate: preparation, characterisation and study of degradation.

PubMed

Colombini, M P; Lanterna, G; Mairani, A; Matteini, M; Modugno, F; Rizzi, M

2001-01-01

This paper describes a method for the synthesis of Copper Resinate, which disappeared from artists' palettes in the eighteenth century. This was carried out by interpreting ancient recipes following a scientific approach. Its characterisation using Fourier Transform-Infrared Spectrometry and Gas Chromatography-Mass Spectrometry demonstrated that it is a mixture containing copper and oxidised abietic acids, mainly dehydroabietic and 7-oxo-dehydroabietic acids, formed during the preparation of the pigment and the curing of the paint layer. The composition of copper resinate paint layers, artificially aged by U.V. irradiation at 365 nm (UV), heating (T), and exposed to atmospheric pollutants (NOX) in a climatic chamber, was investigated. The combination of irradiation and temperature produced a change in colour along with a significant increase in the recovered amount of 7-oxo-dehydroabietic acid. The identification of copper resinate in a sample from an old painting should be related to the presence of the following resin compounds which are stable in the ageing process: dehydroabietic and 7-oxo-dehydroabietic acid pimaradienic acids. Photo-oxidation of the resin acids co-ordinated with copper seem to be the most probable decay mechanism responsible for the colour change in the pigment.

Diagnostic and laboratory test ordering in Northern Portuguese Primary Health Care: a cross-sectional study

PubMed Central

Sá, Luísa; Teixeira, Andreia Sofia Costa; Tavares, Fernando; Costa-Santos, Cristina; Couto, Luciana; Costa-Pereira, Altamiro; Hespanhol, Alberto Pinto; Santos, Paulo

2017-01-01

Objectives To characterise the test ordering pattern in Northern Portugal and to investigate the influence of context-related factors, analysing the test ordered at the level of geographical groups of family physicians and at the level of different healthcare organisations. Design Cross-sectional study. Setting Northern Primary Health Care, Portugal. Participants Records about diagnostic and laboratory tests ordered from 2035 family physicians working at the Northern Regional Health Administration, who served approximately 3.5 million Portuguese patients, in 2014. Outcomes To determine the 20 most ordered diagnostic and laboratory tests in the Northern Regional Health Administration; to identify the presence and extent of variations in the 20 most ordered diagnostic and laboratory tests between the Groups of Primary Care Centres and between health units; and to study factors that may explain these variations. Results The 20 most ordered diagnostic and laboratory tests almost entirely comprise laboratory tests and account for 70.9% of the total tests requested. We can trace a major pattern of test ordering for haemogram, glucose, lipid profile, creatinine and urinalysis. There was a significant difference (P<0.001) in test orders for all tests between Groups of Primary Care Centres and for all tests, except glycated haemoglobin (P=0.06), between health units. Generally, the Personalised Healthcare Units ordered more than Family Health Units. Conclusions The results from this study show that the most commonly ordered tests in Portugal are laboratory tests, that there is a tendency for overtesting and that there is a large variability in diagnostic and laboratory test ordering in different geographical and organisational Portuguese primary care practices, suggesting that there may be considerable potential for the rationalisation of test ordering. The existence of Family Health Units seems to be a strong determinant in decreasing test ordering by Portuguese family

Identification and characterisation of local aerosol sources using high temporal resolution measurements.

PubMed

Contini, D; Donateo, A; Cesari, D; Belosi, F; Francioso, S

2010-09-01

Aerosol and gaseous pollution measurements were carried out at an urban background site in the south of Italy located near an industrial complex. Collection of 24 h samples of PM10 and PM2.5 and successive chemical quantification of metals were performed. Data were compared with measurements taken at a suburban background site, located at 25 km distance. The comparison showed the presence of an industrial contribution with a well defined chemical emission profile, similar, in terms of metals content, to urban emissions. As this made difficult the quantitative characterisation of the contribution of the two sources to atmospheric PM, a statistical method based on the treatment of data arising from high temporal resolution measurements was developed. Data were taken with a micrometeorological station based on an integrating nephelometer (Mie pDR-1200) for optical detection of PM2.5 concentration, with successive evaluation of vertical turbulent fluxes using the eddy-correlation method. Results show that the contribution from the two sources (urban emissions and industrial releases) have a very different behaviour, with the industrial contribution being present at high wind velocity with short concentration peaks (average duration 4 min) associated to strong positive and negative vertical fluxes. The estimated contribution to PM2.5 is 2.3% over long-term averages. The urban emissions are mainly present at low wind velocity, with longer concentration peaks in the morning and late evening hours, generally associated to small positive vertical fluxes. The characterisation of the contribution was performed using deposition velocity V(d) that is on average -3.5 mm s(-1) and has a diurnal pattern, with negligible values during the night and a minimum value of around -9 mm s(-1) late in the afternoon. Results show a correlation between V(d), friction velocity and wind velocity that could be the basis for a parameterisation of V(d) to be used in dispersion codes.

Laboratory space physics: Investigating the physics of space plasmas in the laboratory

NASA Astrophysics Data System (ADS)

Howes, Gregory G.

2018-05-01

Laboratory experiments provide a valuable complement to explore the fundamental physics of space plasmas without the limitations inherent to spacecraft measurements. Specifically, experiments overcome the restriction that spacecraft measurements are made at only one (or a few) points in space, enable greater control of the plasma conditions and applied perturbations, can be reproducible, and are orders of magnitude less expensive than launching spacecraft. Here, I highlight key open questions about the physics of space plasmas and identify the aspects of these problems that can potentially be tackled in laboratory experiments. Several past successes in laboratory space physics provide concrete examples of how complementary experiments can contribute to our understanding of physical processes at play in the solar corona, solar wind, planetary magnetospheres, and the outer boundary of the heliosphere. I present developments on the horizon of laboratory space physics, identifying velocity space as a key new frontier, highlighting new and enhanced experimental facilities, and showcasing anticipated developments to produce improved diagnostics and innovative analysis methods. A strategy for future laboratory space physics investigations will be outlined, with explicit connections to specific fundamental plasma phenomena of interest.

Reliability on intra-laboratory and inter-laboratory data of hair mineral analysis comparing with blood analysis.

PubMed

Namkoong, Sun; Hong, Seung Phil; Kim, Myung Hwa; Park, Byung Cheol

2013-02-01

Nowadays, although its clinical value remains controversial institutions utilize hair mineral analysis. Arguments about the reliability of hair mineral analysis persist, and there have been evaluations of commercial laboratories performing hair mineral analysis. The objective of this study was to assess the reliability of intra-laboratory and inter-laboratory data at three commercial laboratories conducting hair mineral analysis, compared to serum mineral analysis. Two divided hair samples taken from near the scalp were submitted for analysis at the same time, to all laboratories, from one healthy volunteer. Each laboratory sent a report consisting of quantitative results and their interpretation of health implications. Differences among intra-laboratory and interlaboratory data were analyzed using SPSS version 12.0 (SPSS Inc., USA). All the laboratories used identical methods for quantitative analysis, and they generated consistent numerical results according to Friedman analysis of variance. However, the normal reference ranges of each laboratory varied. As such, each laboratory interpreted the patient's health differently. On intra-laboratory data, Wilcoxon analysis suggested they generated relatively coherent data, but laboratory B could not in one element, so its reliability was doubtful. In comparison with the blood test, laboratory C generated identical results, but not laboratory A and B. Hair mineral analysis has its limitations, considering the reliability of inter and intra laboratory analysis comparing with blood analysis. As such, clinicians should be cautious when applying hair mineral analysis as an ancillary tool. Each laboratory included in this study requires continuous refinement from now on for inducing standardized normal reference levels.

In vitro susceptibility of filamentous fungi to itraconazole, voriconazole and posaconazole by Clinical and Laboratory Standards Institute reference method and E-test.

PubMed

Kondori, N; Svensson, E; Mattsby-Baltzer, I

2011-09-01

The use of anti-fungal agents has increased dramatically in recent years and new drugs have been developed. Several methods are available for determinations of their specific biological activities, i.e. the standard method for minimum inhibitory concentration-determination is described in M-38 [Clinical and Laboratory Standards Institute document M-38 (CLSI M-38)]. However, alternative methods, such as the E-test, are currently available in Mycology laboratories. The susceptibilities of clinical isolates of Aspergillus spp. (n = 29), Fusarium spp. (n = 5), zygomycetes (n = 21) and Schizophyllum (n = 1) were determined for itraconazole, voriconazole and posaconazole, using the CLSI M-38-A broth dilution method and also by the E-test. A good overall agreement (83.7%) between the two methods for all drugs and organisms was observed. Analyses of voriconazole showed a better agreement (93%) between the methods than posaconazole and itraconazole (85% and 74% respectively). Aspergillus spp. were the most susceptible fungi to the anti-fungal agents tested in this study. Posaconazole was the most active drug against filamentous fungi in vitro, followed by itraconazole and voriconazole. The latter (voriconazole) demonstrated no significant in vitro activity against zygomycetes. © 2010 Blackwell Verlag GmbH.

Quality Assurance Program for Molecular Medicine Laboratories

PubMed Central

Hajia, M; Safadel, N; Samiee, S Mirab; Dahim, P; Anjarani, S; Nafisi, N; Sohrabi, A; Rafiee, M; Sabzavi, F; Entekhabi, B

2013-01-01

Background: Molecular diagnostic methods have played and continuing to have a critical role in clinical laboratories in recent years. Therefore, standardization is an evolutionary process that needs to be upgrade with increasing scientific knowledge, improvement of the instruments and techniques. The aim of this study was to design a quality assurance program in order to have similar conditions for all medical laboratories engaging with molecular tests. Methods: We had to design a plan for all four elements; required space conditions, equipments, training, and basic guidelines. Necessary guidelines was prepared and confirmed by the launched specific committee at the Health Reference Laboratory. Results: Several workshops were also held for medical laboratories directors and staffs, quality control manager of molecular companies, directors and nominees from universities. Accreditation of equipments and molecular material was followed parallel with rest of program. Now we are going to accredit medical laboratories and to evaluate the success of the program. Conclusion: Accreditation of medical laboratory will be succeeding if its basic elements are provided in advance. Professional practice guidelines, holding training and performing accreditation the molecular materials and equipments ensured us that laboratories are aware of best practices, proper interpretation, limitations of techniques, and technical issues. Now, active external auditing can improve the applied laboratory conditions toward the defined standard level. PMID:23865028

Characterising the Atmospheres of Transiting Planets with a Dedicated Space Telescope

NASA Astrophysics Data System (ADS)

Tessenyi, M.; Ollivier, M.; Tinetti, G.; Beaulieu, J. P.; Coudé du Foresto, V.; Encrenaz, T.; Micela, G.; Swinyard, B.; Ribas, I.; Aylward, A.; Tennyson, J.; Swain, M. R.; Sozzetti, A.; Vasisht, G.; Deroo, P.

2011-10-01

Transiting super-Earths orbiting M dwarfs are excellent targets for the prospect of studying potentially habitable extrasolar planets. While most of the currently known Exoplanets are of the Hot Jupiter and Neptune type, attention is now turning to these super- Earths. Two recent examples are GJ 1214b, found by Charbonneau et al. in 2009, and Cancri 55 e, found by Winn et al. in 2011. These candidates offer the opportunity of obtaining spectral signatures of their atmospheres in transiting scenarios, via data obtained by ground based and space observatories, compared to simulated climate scenarios. With the recent selection of the Exoplanet Characterisation Observatory (EChO) mission by ESA for further studies, I present observational strategies and time requirements for a range of targets characterisable by EChO, with a view to super-Earths orbiting M dwarfs.

Characterisation of a novel enterobacteria phage, CAjan, isolated from rat faeces.

PubMed

Carstens, Alexander B; Kot, Witold; Lametsch, Rene; Neve, Horst; Hansen, Lars H

2016-08-01

In this study, we describe the isolation and characterisation of the novel enterobacteria phage CAjan. This phage belongs to the order Caudovirales and the family Siphoviridae. The phage possesses a linear, double-stranded DNA genome consisting of 59,670 bp with a G+C content of 44.7 % and 91 predicted open reading frames (ORFs). Putative functions were assigned to 39 of the ORFs (37.4 %). The phage structural genes were furthermore functionally characterised by LC MS/MS. CAjan, together with Escherichia phage Seurat and Escherichia phage slur01, represent a novel and genetically distinct clade of Siphoviridae phages that could be considered to constitute a new phage genus. Despite limited sequence similarity, the phages in this group share a number of other common features, including genome structure and the presence of queuosine biosynthesis genes.

Geostatistical characterisation of geothermal parameters for a thermal aquifer storage site in Germany

NASA Astrophysics Data System (ADS)

Rodrigo-Ilarri, J.; Li, T.; Grathwohl, P.; Blum, P.; Bayer, P.

2009-04-01

The design of geothermal systems such as aquifer thermal energy storage systems (ATES) must account for a comprehensive characterisation of all relevant parameters considered for the numerical design model. Hydraulic and thermal conductivities are the most relevant parameters and its distribution determines not only the technical design but also the economic viability of such systems. Hence, the knowledge of the spatial distribution of these parameters is essential for a successful design and operation of such systems. This work shows the first results obtained when applying geostatistical techniques to the characterisation of the Esseling Site in Germany. In this site a long-term thermal tracer test (> 1 year) was performed. On this open system the spatial temperature distribution inside the aquifer was observed over time in order to obtain as much information as possible that yield to a detailed characterisation both of the hydraulic and thermal relevant parameters. This poster shows the preliminary results obtained for the Esseling Site. It has been observed that the common homogeneous approach is not sufficient to explain the observations obtained from the TRT and that parameter heterogeneity must be taken into account.

Comparison of three methods for the detection of Trichinella spiralis infections in pigs by five European laboratories*

PubMed Central

Kohler, G.; Ruitenberg, E. J.

1974-01-01

Three methods employed in the diagnosis of trichinosis (trichinoscopy, digestion method, and immunofluorescence technique) were compared by laboratories in 5 countries of the European economic community. For this purpose, material from 32 pigs infected with 50, 150, 500, and 1 500 T. spiralis larvae was examined. With none of the three methods was it possible to detect with sufficient reliability a T. spiralis infection in pigs infected with 50 larvae. The digestion method and the immunofluorescence technique yielded more reliable results when the infection dose was 150 larvae or more. With trichinoscopy, reliable results were obtained in pigs infected with 500 and 1 500 larvae. With the digestion method and trichinoscopy, the onset of infections was detectable from 3 weeks post infection, the digestion method being more reliable; the immunofluorescence technique yielded positive results from approximately 4-6 weeks post infection. The immunofluorescence technique is applicable for epidemiological surveys. As a routine diagnostic procedure in the slaughterhouse, trichinoscopy and the digestion method are possible alternatives, the latter being more sensitive. PMID:4616776

Design, simulation and characterisation of integrated optics for a microfabricated flow cytometer

NASA Astrophysics Data System (ADS)

Barat, David; Benazzi, Giuseppe; Mowlem, Matthew Charles; Ruano, Jesus Miguel; Morgan, Hywel