326 research outputs found

    Quality data assessment and improvement in pre-processing pipeline to minimize impact of spurious signals in functional magnetic imaging (fMRI)

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    In the recent years, the field of quality data assessment and signal denoising in functional magnetic resonance imaging (fMRI) is rapidly evolving and the identification and reduction of spurious signal with pre-processing pipeline is one of the most discussed topic. In particular, subject motion or physiological signals, such as respiratory or/and cardiac pulsatility, were showed to introduce false-positive activations in subsequent statistical analyses. Different measures for the evaluation of the impact of motion related artefacts, such as frame-wise displacement and root mean square of movement parameters, and the reduction of these artefacts with different approaches, such as linear regression of nuisance signals and scrubbing or censoring procedure, were introduced. However, we identify two main drawbacks: i) the different measures used for the evaluation of motion artefacts were based on user-dependent thresholds, and ii) each study described and applied their own pre-processing pipeline. Few studies analysed the effect of these different pipelines on subsequent analyses methods in task-based fMRI.The first aim of the study is to obtain a tool for motion fMRI data assessment, based on auto-calibrated procedures, to detect outlier subjects and outliers volumes, targeted on each investigated sample to ensure homogeneity of data for motion. The second aim is to compare the impact of different pre-processing pipelines on task-based fMRI using GLM based on recent advances in resting state fMRI preprocessing pipelines. Different output measures based on signal variability and task strength were used for the assessment

    Exploiting novel automated analytical methodologies for the monitoring of environmental organic pollutants, and its potential incorporation to environmental monitoring regulations

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    Se han desarrollado métodos analíticos basados en cromatografía y detección por espectrometría de masas para la detección de múltiples compuestos orgánicos a niveles traza en muestras de interés ambiental. Se han determinado compuestos volátiles en aire atmosférico de Mallorca y varias plantas de tratamiento de residuos y vertederos, y fármacos de consumo humano en muestras del medioambiente acuático de Mallorca, plantas de tratamiento de aguas y lixiviados de vertederos. Con estos datos se ha evaluado la necesidad de modificar los planes de vigilancia ambiental para asegurar la calidad del medioambiente de Mallorca.We have developed analytical methodologies based on chromatography and mass spectrometry for the detection of multiple different organic compounds in the trace levels in samples of environmental interest. Volatile organic compounds have been determined in the atmospheric air of Mallorca as well as some waste treatment plants and landfills. Pharmaceuticals for human consumption have been investigated in several samples of the aquatic environment of Mallorca as well as some wastewater treatment plants and landfill leachates. Based on these data it has been evaluated the necessity to modify the environmental monitoring regulations to save the quality of the Mallorca’s environment

    Exploiting novel automated analytical methodologies for the monitoring of environmental organic pollutants, and its potential incorporation to environmental monitoring regulations

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    Se han desarrollado métodos analíticos basados en cromatografía y detección por espectrometría de masas para la detección de múltiples compuestos orgánicos a niveles traza en muestras de interés ambiental. Se han determinado compuestos volátiles en aire atmosférico de Mallorca y varias plantas de tratamiento de residuos y vertederos, y fármacos de consumo humano en muestras del medioambiente acuático de Mallorca, plantas de tratamiento de aguas y lixiviados de vertederos. Con estos datos se ha evaluado la necesidad de modificar los planes de vigilancia ambiental para asegurar la calidad del medioambiente de MallorcaWe have developed analytical methodologies based on chromatography and mass spectrometry for the detection of multiple different organic compounds in the trace levels in samples of environmental interest. Volatile organic compounds have been determined in the atmospheric air of Mallorca as well as some waste treatment plants and landfills. Pharmaceuticals for human consumption have been investigated in several samples of the aquatic environment of Mallorca as well as some wastewater treatment plants and landfill leachates. Based on these data it has been evaluated the necessity to modify the environmental monitoring regulations to save the quality of the Mallorca’s environment

    Guidelines for Drinking-Water Quality

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    The fourth edition of the World Health Organization's (WHO) Guidelines for drinking-water quality (GDWQ) builds on over 50 years of guidance by WHO on drinking-water quality, which has formed an authoritative basis for the setting of national regulations and standards for water safety in support of public health.It is the product of significant revisions to clarify and elaborate on ways of implementing its recommendations of contextual hazard identification and risk management, through the establishment of health-based targets, catchment-to-consumer water safety plans and independent surveillance.This first addendum updates the fourth edition. Updates reflect new evidence and further, provides additional explanations to support better understanding and application of the guidance

    Sensory experiences of individuals with Autism Spectrum Disorder and autistic traits: a mixed methods approach

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    There has been a recent increase in research into sensory sensitivity in Autism Spectrum Disorders (ASDs), which has prompted the inclusion of sensory issues as an explicit criterion in the impending revision of diagnostic guidelines (DSM-5: American Psychiatric Association, 2010). However, one of the most interesting aspects of research in this field is that a clear disparity exists between the results of self- or parent-report studies and behavioural studies. The former class of studies shows that those with ASD report clear, consistent differences in their sensory experiences (Baranek et al., 2006; Crane et al., 2009; Leekam et al., 2007), whereas the findings in the behavioural field are complex to interpret, with all but a few areas of sensory processing (e.g. visual search: Joliffe & Baron-Cohen, 1997; Shah & Frith, 1983, 1993) demonstrating consistent consensus (e.g. Dudova et al., 2011; Tavassoli et al., 2012a). The thesis presented here aims to explore the nature of sensory sensitivities in those with ASD and the broader autism phenotype (BAP) further using a combination of qualitative and quantitative research designs. In addition, an approach was developed (the Sensory Audit: Chapter 8) which can be used to objectively assess an environment for sensory stressors. Chapters 2 and 3 report the development of a sensory questionnaire (GSQ: Robertson & Simmons, 2012), which was administered to those with varying AQ scores, as measured by the Autism Spectrum Quotient (AQ: Baron-Cohen et al., 2001). There were both quantitative (Chapter 2) and qualitative (Chapter 3) features of the questionnaire. In the quantitative component, seven modalities were assessed (vision, audition, gustation, olfaction, touch, vestibular processing and proprioception), taking into account both hyper- and hypo-sensitivity to stimuli. We found that there was a strong, positive relationship between sensory sensitivity and AQ score, with medium scorers (who would be unlikely to be diagnosed with ASD) reporting significantly more difficulties with sensory stimuli than low scorers. For Chapter 3, we found that those with high levels of autistic traits (i.e. may be likely to have a diagnosis of ASD) tended to report using different coping techniques from medium and low scorers (e.g. avoiding situations and using sensory soothing rather than non-sensory soothing). The results from these studies suggest that sensory issues may be prevalent throughout the population and that the differences observed in Chapter 2 are mirrored in the themes extracted for each group in Chapter 3. The second set of studies (Chapters 4-6) report data from three focus groups (caregivers of those with autism, adults with ASD and an elderly control group), as well as from interactive group interviews with children who have autism. Although similar themes (e.g. control, consequences of problematic stimuli and positive effects of sensory stimuli) arose in all four studies, there were different types of information gathered from the groups. For those with ASD (Chapter 4 and Chapter 5), the discussion mainly centred around how sensory stimuli made them feel, and the implications of this for them. For the caregivers (Chapter 4) and the elderly group (who mainly discussed their relatives’ experiences) (Chapter 6), the themes reflected their own experiences, concentrating on the implications of adverse reactions to sensory stimuli (for both themselves and their loved ones). The data from these studies provide insight into living with someone who has sensory issues, for both those with a diagnosis of ASD and their caregivers, as well as the relatives of elderly individuals suffering from vision and hearing loss. Chapter 7 reports a study into the relationship between olfactory processing and the broader autism phenotype (as measured by the AQ). Participants completed the AQ as well as the Sniffin’ Sticks Extended Test. A subset of the sample (n=62) also completed the Glasgow Sensory Questionnaire (GSQ) that was developed as part of Chapter 2. As expected, there were no significant differences in the Threshold, Discrimination or Identification performance of those with high and low AQ scores. However, there was significantly greater intra-participant variability in the Threshold scores for the top 15% of scorers on the AQ. Furthermore, a similar relationship to that reported in Chapter 2 between sensory score and autistic traits was observed. These results indicate that there may be other differences in various aspects of performance in those with ASD that are not being targeted by current behavioural paradigms (which may explain the disparity between reported sensory differences and those observed using direct measurement). Finally, the last study reported is that of the development of a pilot Sensory Audit. This was an effort to apply the information gained from our previous research in a practical, useful way for individuals with ASD. Details of the development of the Sensory Audit, as well as the results of the pilot study are reported in Chapter 8. By making this freely available, we hope to help companies ensure that their working environments do not contain any undue stressors that could increase stress for those with sensory issues in their workforce. The results are discussed in light of three overarching themes of the thesis as a whole. Firstly, the potential mechanisms underlying sensory responsiveness in ASD, with the suggestion that emotional states may be an important avenue to consider in future research. Secondly, the impact of atypical sensory processing on caregivers, with particular attention paid to the compensation of these issues by caregivers, and the social implications of challenging behaviour instigated by unpleasant sensory stimuli. Thirdly, the data are discussed in light of the relationship between sensory processing and the broader autism phenotype (as measured using the AQ). The greater levels of intra-participant variability in the olfactory task (Chapter 7) are highlighted, as is the elevated sensory responsiveness of those with moderate levels of autistic traits reported in Chapters 2 and 3. The final section of the discussion deals with the limitations of the thesis, potential practical applications of the research and future directions

    Novel Analysis on Aroma Compounds of Wine, Vinegar and Derived Products

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    Aroma compounds are some of the main compounds responsible for the acceptance of oenological products such as wine, vinegar and derived products. These kinds of compounds are produced during the winemaking process and they can be affected by natural, geographical and human factors: raw material, alcoholic and acetic fermentation, ageing, distillation, technological processes, etc. Therefore, it is very important to study and to characterize the aromatic fraction of these oenological beverages in order to improve the quality of the final product. Therefore, this book is focused on some recent studies related to the study of the volatile composition of wine, vinegar and derived products, in many different fields of science: oenology, chemistry, food science and technology, biochemistry, microbiology, biotechnology, engineering, sensory analysis, etc., and it shows the great importance of both sensory and analytical study of oenological products aroma and how they are influenced by the different stages and conditions under which they are elaborated. In this book, you will find 12 valuable scientific contributions: 2 literature reviews and 10 original research works, which deal with the latest advances in both sensory and analytical tools in order to evaluate the effects of different techniques or winemaking stages on the oenological products’ aromas

    Environmental Research Newsletter February 1989 No. 3

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    The chemical and genetic basis of tomato flavour

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    Tomatoes often lack the characteristic good taste that consumers expect. In recent years, the fruit and vegetable industry has focused on traits such as yield, colour, and fruit size; however, flavour has been largely forgotten, at least for varieties that are grown in bulk and are cheap to purchase. Tomato volatiles are one of the most important flavour contributors along with sugars and organic acids. Over 400 volatiles are present in tomato, but only about 30 are considered critical to tomato flavour. The purpose of this study was to identify volatile Quantitative Trait Loci (vQTL) using publicly available Solanum pennellii and Solanum habrochaites introgression lines (ILs). Detection of vQTL is an essential milestone for identification of candidate genes involved in tomato flavour. Identification of vQTL was undertaken by screening the ILs using Atmospheric Pressure Chemical Ionisation Mass Spectrometry (APCI-MS) and Gas Chromatography Mass Spectrometry (GC-MS). Additionally key volatiles and their interactions were evaluated in a series of sensory experiments using tomato juice and tomato purée. The study revealed that, the S. pennellii population had several major effects including those on IL1-4, which had a vQTL for C6 volatile E-2-hexenal. It was possible to identify a sub-IL, 1-4-1 that also harboured this vQTL. In this IL1-4-1 region of chromosome 1, 122 genes were present including a possible, candidate gene likely to be involved in lipoxygenase pathway. The sensory experiments showed strong impact of methyl salicylate on other volatiles; E-2-hexenal and citral showed positive effects in purée studies. Determined taste detection thresholds for volatiles in tomato juice and purée were established. Keywords: volatile, genes, tomato juice, tomato purée, flavou
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