Perceived energy compensation following various sports: an age and sex comparison. Preliminary observations.

Following periods of physical activity, it is not uncommon for exercisers to increase their energy intake as a reward deemed 'earned'. Consumers' awareness of the energy within food and expended from exercise has previously been found to be limited. Therefore, the aim was to investigate whether habitual exercisers (50 adults and 49 children from 5 sports clubs) were able to conceptualise the energy expenditure (EE), following 1 h of their regular sports training, into a quantifiable amount of perceived energy compensation (PEC) in the form of food (chocolate) or drink (sports drink). Mean percentage accuracy for the PEC against EE matched <30% (± 29%), a significant underestimation irrespective of sex or sport. Percentage accuracy failed to significantly correlate to age. These findings indicate a necessity to improve nutrition education surrounding the energy costs of exercise relative to the energy contained within foods/drinks for both adults and children.

The use of a gas chromatograph coupled to a metal oxide sensor for rapid assessment of stool samples from irritable bowel syndrome and inflammatory bowel disease patients.

There is much clinical interest in the development of a low-cost and reliable test for diagnosing inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS), two very distinct diseases that can present with similar symptoms. The assessment of stool samples for the diagnosis of gastro-intestinal diseases is in principle an ideal non-invasive testing method. This paper presents an approach to stool analysis using headspace gas chromatography and a single metal oxide sensor coupled to artificial neural network software. Currently, the system is able to distinguish samples from patients with IBS from patients with IBD with a sensitivity and specificity of 76% and 88% respectively, with an overall mean predictive accuracy of 76%.

Towards point of care testing for C. difficile infection by volatile profiling, using the combination of a short multi-capillary gas chromatography column with metal oxide sensor detection.

Rapid volatile profiling of stool sample headspace was achieved using a combination of short multi-capillary chromatography column (SMCC), highly sensitive heated metal oxide semiconductor (MOS) sensor and artificial neural network (ANN) software. For direct analysis of biological samples this prototype offers alternatives to conventional GC detectors and electronic nose technology. The performance was compared to an identical instrument incorporating a long single capillary column (LSCC). The ability of the prototypes to separate complex mixtures was assessed using gas standards and homogenised in house 'standard' stool samples, with both capable of detecting more than 24 peaks per sample. The elution time was considerably faster with the SMCC resulting in a run time of 10 minutes compared to 30 minutes for the LSCC. The diagnostic potential of the prototypes was assessed using 50 C. difficile positive and 50 negative samples. The prototypes demonstrated similar capability of discriminating between positive and negative samples with sensitivity and specificity of 85% and 80% respectively. C. difficile is an important cause of hospital acquired diarrhoea, with significant morbidity and mortality around the world. A device capable of rapidly diagnosing the disease at the point of care would reduce cases, deaths and financial burden.

Identifying and relating biological concepts in the Catalogue of Life.

BACKGROUND: In this paper we describe our experience of adding globally unique identifiers to the Species 2000 and ITIS Catalogue of Life, an on-line index of organisms which is intended, ultimately, to cover all the world's known species. The scientific species names held in the Catalogue are names that already play an extensive role as terms in the organisation of information about living organisms in bioinformatics and other domains, but the effectiveness of their use is hindered by variation in individuals' opinions and understanding of these terms; indeed, in some cases more than one name will have been used to refer to the same organism. This means that it is desirable to be able to give unique labels to each of these differing concepts within the catalogue and to be able to determine which concepts are being used in other systems, in order that they can be associated with the concepts in the catalogue. Not only is this needed, but it is also necessary to know the relationships between alternative concepts that scientists might have employed, as these determine what can be inferred when data associated with related concepts is being processed. A further complication is that the catalogue itself is evolving as scientific opinion changes due to an increasing understanding of life. RESULTS: We describe how we are using Life Science Identifiers (LSIDs) as globally unique identifiers in the Catalogue of Life, explaining how the mapping to species concepts is performed, how concepts are associated with specific editions of the catalogue, and how the Taxon Concept Schema has been adopted in order to express information about concepts and their relationships. We explore the implications of using globally unique identifiers in order to refer to abstract concepts such as species, which incorporate at least a measure of subjectivity in their definition, in contrast with the more traditional use of such identifiers to refer to more tangible entities, events, documents, observations, etc. CONCLUSIONS: A major reason for adopting identifiers such as LSIDs is to facilitate data integration. We have demonstrated the incorporation of LSIDs into the Catalogue of Life, in a manner consistent with the biodiversity informatics community's conventions for LSID use. The Catalogue of Life is therefore available as a taxonomy of organisms for use within various disciplines, including biomedical research, by software written with an awareness of these conventions.

A sensor system for monitoring the simple gases hydrogen, carbon monoxide, hydrogen sulfide, ammonia and ethanol in exhaled breath.

A sensor array system was constructed incorporating electrochemical sensors for hydrogen, carbon monoxide, hydrogen sulfide and ethanol, a ceramic sensor for total volatiles and a dye-based optical ammonia sensor. The system was calibrated using standard gases balanced with dry air. Limit of detection and % relative standard deviation values (n = 10) for the sensors in the array are hydrogen (0.1 ppm, 2.6%), carbon monoxide (0.4 ppm, 2.1%), ethanol (0.5 ppm, 1.5%), hydrogen sulfide (0.1 ppm, 1.5%) and ammonia (0.6 ppm, 10.7%). Humidity effects were assessed by calibrating with humidified standard gases (hydrogen, carbon monoxide) or spiked breath samples in Tedlar bags (hydrogen sulfide, ethanol and ammonia). The calibration data were used to establish a cross-sensitivity matrix. The concentration of breath volatiles was found to be dependent on exhalation rate and exhalation volume. A test protocol based on these data required volunteers to exhale 1 litre of breath at a rate between 7.5 and 17.5 l min(-1). Sensor responses were measured for 40 s then purged at 7 l min(-1) (150 s). A longitudinal study was undertaken of ten asymptomatic volunteers over a five-day period. Volunteers ate an ad hoc diet, but fasted prior to giving the first breath sample and then gave samples every hour for 8 h. Breath hydrogen levels for volunteers showed large variations within a day and also from day to day. Fasting levels ranged between 0.3 and 34.1 ppm (mean 9.1 ppm). The carbon monoxide levels for non-smokers were between 0.6 and 4.9 ppm (mean 2.1 ppm), whilst for smokers they were between 8.3 and 18.7 ppm (mean 12.8 ppm). The measured levels of other gases on breath were as follows: hydrogen sulfide (0-1.3 ppm, mean 0.33 ppm), ethanol (0-3.9 ppm, mean 0.62 ppm) and ammonia (0-1.3 ppm mean 0.42 ppm). The system was capable of direct quantitative measurements of low concentrations of a range of volatiles on exhaled breath. The measured values for compounds on the breath of asymptomatic volunteers were in broad agreement with quoted literature ranges. The system will now be assessed in a clinical setting.

The characteristics of novel low-cost sensors for volatile biomarker detection.

For breath analyses, volatile detectors capable of sensing extremely low concentrations in the sub-ppm range are required. Novel room temperature sensors were fabricated based on ultraviolet light activation of nanoparticulate metal oxide surfaces using light emitting diodes. These sensors gave reversible electrical resistance changes in the low ppm/ppb range to volatile organic compounds found in breath, including acetone, acetaldehyde, pentane and ethanol.

An analysis of volatiles in the headspace of the faeces of neonates.

A gas chromatography/mass spectrometry (GCMS) analysis of the headspace from the faeces of neonates was undertaken to record the volatiles associated with preterm babies on a neonatal unit. The compounds ethanol, acetone, 2-ethyl-1-hexanol, 3-methylbutanal, hexanal and 2,3-butanedione occurred with the highest frequency. The volatiles analysed were then compared to a previously published study of the volatiles from asymptomatic adult faeces. Fewer compounds were found in the neonatal faeces and virtually no sulfides were detected, in contrast to the adult samples where carbon disulfide, dimethyl disulfide and dimethyl sulfide were ubiquitous. In addition, 7 of the most abundant 15 volatile compounds were found to be aldehydes, while in contrast only 2, acetaldehyde and benzaldehyde, were present in the most abundant 15 compounds found in the headspace of adult faeces. 2-Ethyl-1-hexanol was considerably more abundant in the neonate stool compared to adult stool, and probably reflects high exposure to plastic materials containing plasticizers. The potential of disease diagnoses from the analysis of volatiles emitted from neonate faeces is discussed.