Loss on ignition as a method for estimating organic and carbonate content in sediments: reproducibility and comparability of results

Five test runs were performed to assess possible bias when performing the loss on ignition (LOI) method to estimate organic matter and carbonate content of lake sediments. An accurate and stable weight loss was achieved after 2 h of burning pure CaCO3 at 950 °C, whereas LOI of pure graphite at 530 °C showed a direct relation to sample size and exposure time, with only 40-70% of the possible weight loss reached after 2 h of exposure and smaller samples losing weight faster than larger ones. Experiments with a standardised lake sediment revealed a strong initial weight loss at 550 °C, but samples continued to lose weight at a slow rate at exposure of up to 64 h, which was likely the effect of loss of volatile salts, structural water of clay minerals or metal oxides, or of inorganic carbon after the initial burning of organic matter. A further test-run revealed that at 550 °C samples in the centre of the furnace lost more weight than marginal samples. At 950 °C this pattern was still apparent but the differences became negligible. Again, LOI was dependent on sample size. An analytical LOI quality control experiment including ten different laboratories was carried out using each laboratory's own LOI procedure as well as a standardised LOI procedure to analyse three different sediments. The range of LOI values between laboratories measured at 550 °C was generally larger when each laboratory used its own method than when using the standard method. This was similar for 950 °C, although the range of values tended to be smaller. The within-laboratory range of LOI measurements for a given sediment was generally small. Comparisons of the results of the individual and the standardised method suggest that there is a laboratory-specific pattern in the results, probably due to differences in laboratory equipment and/or handling that could not be eliminated by standardising the LOI procedure. Factors such as sample size, exposure time, position of samples in the furnace and the laboratory measuring affected LOI results, with LOI at 550 °C being more susceptible to these factors than LOI at 950 °C. We, therefore, recommend analysts to be consistent in the LOI method used in relation to the ignition temperatures, exposure times, and the sample size and to include information on these three parameters when referring to the method.

Comparability of Outcome Frameworks in Medical Education: Implications for framework development

Background: The demand for international harmonization in medical education increases with the growing mobility of students and health professionals. Many medical societies and governmental offices have issued outcome frameworks (OF), which describe aims and contents of medical education based on competencies. These national standards affect the development of curricula as well as assessment and licensing procedures. Comparing OF and identifying factors that limit their comparability may thus foster international harmonization of medical education. Summary of Work: We conducted a systematic search for national OF in MedLine, EmBase and the internet. We included all OF in German or English that resulted from a national consensus process and were published or endorsed by a national society or governmental body. We extracted information in five predetermined categories: history of origin, audience, formal structure, medical schooling system and key terms. Summary of Results: Out of 1816 results, 13 OF were included into further analyses. OF reference each other, often without addressing existing differences (e.g. in target audiences). The two most cited OF are “CanMEDs” and “Scottish Doctor”. OF differ especially in their level of detail as well as in the underlying educational system. Discussion and Conclusions: Based on our results we propose a two-step blueprint for OF, that may help to establish comparability for internationally aligned key features – so-called “core competencies” – while at the same time allowing for necessary regional adaptations in terms of “secondary competencies”. Take-home messages: Considerable differences in at least five categories of OF currently hinder the comparability of outcome frameworks.

THE USE OF MULTIVARIATE ANALYSIS OF COVARIANCE IN EVALUATING THE COMPARABILITY OF LABORATORY DETERMINATIONS IN COOPERATIVE STUDIES

The role of clinical chemistry has traditionally been to evaluate acutely ill or hospitalized patients. Traditional statistical methods have serious drawbacks in that they use univariate techniques. To demonstrate alternative methodology, a multivariate analysis of covariance model was developed and applied to the data from the Cooperative Study of Sickle Cell Disease.^ The purpose of developing the model for the laboratory data from the CSSCD was to evaluate the comparability of the results from the different clinics. Several variables were incorporated into the model in order to control for possible differences among the clinics that might confound any real laboratory differences.^ Differences for LDH, alkaline phosphatase and SGOT were identified which will necessitate adjustments by clinic whenever these data are used. In addition, aberrant clinic values for LDH, creatinine and BUN were also identified.^ The use of any statistical technique including multivariate analysis without thoughtful consideration may lead to spurious conclusions that may not be corrected for some time, if ever. However, the advantages of multivariate analysis far outweigh its potential problems. If its use increases as it should, the applicability to the analysis of laboratory data in prospective patient monitoring, quality control programs, and interpretation of data from cooperative studies could well have a major impact on the health and well being of a large number of individuals. ^

Comparability of perceptual analysis of speech characteristics in Australian and Swedish speakers with multiple sclerosis

The aims of the present study were to compare the perceptual assessments of deviant speech signs (dysarthria) exhibited by Australian and Swedish speakers with multiple sclerosis (MS) and to explore whether judgements of dysarthria differed depending on whether the speakers and the judges spoke the same or different languages. Ten Australian and 10 Swedish individuals with MS (matched as closely as possible for age, gender, progression type and severity of dysarthria) were assessed by 2 Australian and 2 Swedish clinically experienced judges using a protocol including 33 speech parameters. Results show that the following perceptual dimensions were identified by both pairs of judges in both groups of speakers to a just noticeable or moderate degree: imprecise consonants, inappropriate pitch level, reduced general rate, and glottal fry. The reliability (Spearman rank-order correlation) of the consensus ratings from the Australian and the Swedish judges was high, with a mean rho of 85.7 for the Australian speakers and mean rho of 84.3 for the Swedish speakers. The most difficult perceptual parameters to assess (i.e. to agree on) included harshness, level of pitch and loudness, precision of consonants and general stress pattern. The study indicated that perceptual assessments of speech characteristics in individuals with MS are informative and can be achieved with high inter-judge reliability irrespective of the judge's knowledge of the speaker's language. Copyright (C) 2003 S. Karger AG, Basel.

Comparability of skin screening histories obtained by telephone interviews and mailed questionnaires: A randomized crossover study

The comparability of information collected through telephone interviews and information collected through mailed questionnaires has not been well studied. As part of the first phase of a randomized controlled trial of population screening for melanoma in Queensland, Australia, the authors compared histories of skin examination reported in telephone interviews and self-administered mailed questionnaires. A total of 1,270 subjects each completed a telephone interview and a mailed questionnaire 1 month apart in 1999; 564 subjects received the interview first, and 706 received the mailed questionnaire first. Agreement between the two methods was 91.2% and 88.6% for whole-body skin examination by a physician in the last 12 months and the last 3 years, respectively, and 81.9% for whole-body skin self-examination in the last 12 months. Agreement was lower for any skin self-examination. Agreement between the two methods was similar regardless of whether the interview or the questionnaire was administered first. Missing data were less frequent for interviews (0.5%) than for mailed questionnaires (3.8%). Costs were estimated at A$9.55 (US$6.21) per completed interview and A$3.01 (US$1.96) per questionnaire. The similarity of results obtained using telephone interviews and mailed questionnaires, coupled with the substantially higher cost of telephone interviews, suggests that self-administered mailed questionnaires are an appropriate method of assessing this health behavior.

Polyethism and comparability of termite choice assays in a model system using Microcerotermes turneri (Termitidae : Termitinae): Implications for standardised testing techniques

Traditional measures of termite food preference assess consequences of foraging behavior such as wood consumption, aggregation and/or termite survivorship. Although studies have been done to investigate the specifics of foraging behavior this is not generally integrated into choice assay experiments. Here choice assays were conducted with small isolated (orphaned) groups of workers and compared with choice assays involving foragers from whole nests (non-orphaned) in the laboratory. Aggregation to two different wood types was used as a measure of preference. Specific worker caste and instars participating in initial exploration were compared between assay methods, with samples of termites taken from nest carton material and sites where termites were feeding. Aggregation results differ between choice assay techniques. Castes and instars responsible for initial exploration, as determined in whole nest trials, were not commonly found exploring in isolated group trials, nor were they numerous in termites taken from active feeding sites. Consequently the use of small groups of M. turneri worker termites extracted from active feeding sites may not be appropriate for use in choice assays.

Comprehensive human urine standards for comparability and standardization in clinical proteome analysis

Urine proteomics is emerging as a powerful tool for biomarker discovery. The purpose of this study is the development of a well-characterized "real life" sample that can be used as reference standard in urine clinical proteomics studies.

The problem posed by exam choice on the comparability of results in the Finnish matriculation examination

The article focuses on the upper secondary matriculation examination in Finland as a school leaving and university entrance examination. The presented research addresses the question of whether increased choice of the subject-specific examinations has the potential to undermine the comparability of examination results and to direct students’ choices not only in the examination but already beforehand at school. The authors refer to Finland’s tradition of more than 160 years of a national examination connecting the academic track of upper secondary schools with universities. The authors explain the Finnish system by describing the adoption of a course-based (vs. class- or year-based) curriculum for the three-year upper secondary education and the subsequent reforms in the matriculation examination. This increases students’ choices considerably with regard to the subject-specific exams included in the examination (a minimum of four). As a result, high-achieving students compete against each other in the more demanding subjects while the less able share the same normal distribution of grades in the less demanding subjects. As a consequence, students tend to strategic exam-planning, which in turn affects their study choices at school, often to the detriment of the more demanding subjects and, subsequently, of students’ career opportunities, endangering the traditional national objective of an all-round pre-academic upper secondary education. This contribution provides an overview of Finnish upper secondary education and of the matriculation examination (cf. Klein, 2013) while studying three separate but related issues by using data from several years of Finnish matriculation results: the relation of the matriculation examination and the curriculum; the problems of comparability vis-à-vis university entry due to the increased choice within the examination; the relations between students’ examination choices and their course selection and achievement during upper secondary school. (DIPF/Orig.)

Publishing and impact criteria, and their bearing on Translation Studies: In search of comparability

This paper questions the current concept of quality as used in research assessment rankings and peer review, with special reference to the link often established between impact and the way this impact is measured in the form of citation counting. Taking translation studies as a case study, we will offer a two-level approach to reveal both the macro- and micro-level biases that exist in this regard. We will first review three key aspects related to the idea of the quality of publications, namely peer review, journal indexing, and journal impact factor. We will then pinpoint some of the main macro-level problems regarding current practices and criteria as applied to translation studies, such as Thomson Reuters World of Science's journal coverage, citation patterns, and publication format. Next we will provide a micro-textual and practical perspective, focusing on citation counts and suggesting a series of corrective measures to increase comparability.

Informação em mortalidade: o uso das regras internacionais para a seleção da causa básica

A análise da mortalidade tem sido muito usada em saúde pública, e a causa básica da morte é uma variável bastante estudada. Na maioria dos países, há obrigatoriedade de o médico preencher a declaração de óbito (DO), informando às autoridades a ocorrência do evento, características do falecido e causas da morte. Quando há dois ou mais diagnósticos na declaração das causas da morte, surge a questão da seleção da causa básica. As normas para o preenchimento das causas de morte pelos médicos nas DO e as regras para a seleção da causa básica, quando mais de uma causa é declarada, estão definidas pela OMS, visando à comparabilidade internacional. O objetivo deste trabalho é avaliar se a aplicação das Regras Internacionais de Classificação da causa básica permite a seleção da real causa básica, mesmo se declarada incorretamente pelo médico. O material pertence ao "Estudo sobre a mortalidade de mulheres em idade fértil", sendo que 1.315 casos satisfizeram os requisitos de inclusão. Para cada morte foi realizada uma investigação através de entrevistas domiciliárias, consultas aos prontuários hospitalares e assemelhados. Médicos treinados e calibrados preenchiam uma DO nova, após a leitura de toda a informação, e selecionavam a "verdadeira" causa básica da morte. Esta era comparada com a causa básica da DO original, obtida por meio das Regras Internacionais. Entre as DO, em 1.192 (90,6%) houve concordância com a verdadeira causa básica obtida após a investigação. Concluiu-se que as Regras Internacionais permitem selecionar a real causa básica, mesmo quando o médico preenche inadequadamente a DO