53 research outputs found

    Investigating the effect of increasing cloth size and cloth number in a spinning mesh disc reactor (SMDR):A study on the reactor performance

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    The spinning mesh disc reactor (SMDR) is a rotating catalytic reactor with a potential to facilitate process intensification. In this study, the scale-up of a newly designed SMDR has been demonstrated by increasing (i) cloth size and (ii) cloth number for tributyrin hydrolysis and nitroaldol condensation reaction. The effect of spinning speed, cloth size and cloth number was investigated using design of experiments and the results show an increase in the cloth size or cloth number leads to a higher reaction rate. This is due to (i) an increased catalyst loading with increase in surface area and volume of the cloth stack and (ii) reduced film thickness with increasing shear forces and longer residence times improving the overall mass transfer. Addition of multiple cloths of increasing cloth sizes further improved the reaction rates at higher substrate concentration. A maximum reaction rate of 6.9 mM min−1 and 0.043 mmol min-1 was obtained for three 50 cm cloths for tributyrin hydrolysis and nitroaldol condensation reaction respectively. These results highlight the potential routes for the SMDR scale-up without a loss in the reaction efficiency for a range of catalytic reactions, thus allowing for a tuneable operation of the SMDR for industrial applications

    Investigating the effect of increasing cloth size and cloth number in a spinning mesh disc reactor (SMDR):A study on the reactor performance

    Get PDF
    The spinning mesh disc reactor (SMDR) is a rotating catalytic reactor with a potential to facilitate process intensification. In this study, the scale-up of a newly designed SMDR has been demonstrated by increasing (i) cloth size and (ii) cloth number for tributyrin hydrolysis and nitroaldol condensation reaction. The effect of spinning speed, cloth size and cloth number was investigated using design of experiments and the results show an increase in the cloth size or cloth number leads to a higher reaction rate. This is due to (i) an increased catalyst loading with increase in surface area and volume of the cloth stack and (ii) reduced film thickness with increasing shear forces and longer residence times improving the overall mass transfer. Addition of multiple cloths of increasing cloth sizes further improved the reaction rates at higher substrate concentration. A maximum reaction rate of 6.9 mM min−1 and 0.043 mmol min-1 was obtained for three 50 cm cloths for tributyrin hydrolysis and nitroaldol condensation reaction respectively. These results highlight the potential routes for the SMDR scale-up without a loss in the reaction efficiency for a range of catalytic reactions, thus allowing for a tuneable operation of the SMDR for industrial applications

    How instructions modify perception: An fMRI study investigating brain areas involved in attributing human agency

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    Behavioural studies suggest that the processing of movement stimuli is influenced by beliefs about the agency behind these actions. The current study examined how activity in social and action related brain areas differs when participants were instructed that identicalmovement stimuli were either human or computer generated.Participants viewed a series of point-light animation figures derived frommotion-capture recordings of amoving actor, while functional magnetic resonance imaging (fMRI) was used to monitor patterns of neural activity. The stimuli were scrambled to produce a range of stimulus realism categories; furthermore, before each trial participants were told that they were about to view either a recording of human movement or a computersimulated pattern of movement. Behavioural results suggested that agency instructions influenced participants' perceptions of the stimuli. The fMRI analysis indicated different functions within the paracingulate cortex: ventral paracingulate cortex was more active for human compared to computer agency instructed trials across all stimulus types, whereas dorsal paracingulate cortex was activated more highly in conflicting conditions (human instruction, lowrealismor vice versa). These findings support the hypothesis that ventral paracingulate encodes stimuli deemed to be of human origin,whereas dorsal paracingulate cortex is involvedmore in the ascertainment of human or intentional agency during the observation of ambiguous stimuli. Our results highlight the importance of prior instructions or beliefs on movement processing and the role of the paracingulate cortex in integrating prior knowledge with bottom-up stimuli

    Visible lesbians and invisible bisexuals: Appearance and visual identities among bisexual women

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    A number of feminist scholars have argued that dress and appearance can be used to critique the dominant culture and explore alternative subjectivities. Research on non-heterosexual visual identities has explored the role that appearance and clothing practices can play in the construction of individual identities and collective communities. However, bisexual women are largely invisible in these discussions. The minimal existing research suggests that bisexual women are unable to communicate their sexuality through their clothing and appearance. This study explored how bisexual women manage their bodies and appearance in relation to their bisexuality. Qualitative interviews were conducted with 20 self-identified bisexual women and the data were analysed using thematic analysis. The participants reported particular visual aesthetics associated with an embodied lesbian identity; however, they reported no visual image of bisexual women. Nonetheless, despite their lack of access to a distinct visual identity, the women negotiated ways in which to incorporate their bisexual identity into their dress and appearance, and considered their bisexuality an important aspect of their identity, which they would like to be recognised and acknowledged

    The development of metacognitive ability in adolescence

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    Introspection, or metacognition, is the capacity to reflect on our own thoughts and behaviours. Here, we investigated how one specific metacognitive ability (the relationship between task performance and confidence) develops in adolescence, a period of life associated with the emergence of self-concept and enhanced self-awareness. We employed a task that dissociates objective performance on a visual task from metacognitive ability in a group of 56 participants aged between 11 and 41 years. Metacognitive ability improved significantly with age during adolescence, was highest in late adolescence and plateaued going into adulthood. Our results suggest that awareness of one’s own perceptual decisions shows a prolonged developmental trajectory during adolescence

    Influence of COMT genotype and affective distractors on the processing of self-generated thought

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    The catechol-O-methyltransferase (COMT) enzyme is a major determinant of prefrontal dopamine levels. The Val158Met polymorphism affects COMT enzymatic activity and has been associated with variation in executive function and affective processing. This study investigated the effect of COMT genotype on the flexible modulation of the balance between processing self-generated and processing stimulus-oriented information, in the presence or absence of affective distractors. Analyses included 124 healthy adult participants, who were also assessed on standard working memory (WM) tasks. Relative to Val carriers, Met homozygotes made fewer errors when selecting and manipulating self-generated thoughts. This effect was partly accounted for by an association between COMT genotype and visuospatial WM performance. We also observed a complex interaction between the influence of affective distractors, genotype and sex on task accuracy: male, but not female, participants showed sensitivity to the affective distractors that was dependent on COMT genotype. This was not accounted for by WM performance. This study provides novel evidence of the role of dopaminergic genetic variation on the ability to select and manipulate self-generated thoughts. The results also suggest sexually dimorphic effects of COMT genotype on the influence of affective distractors on executive function

    The audience effect in adolescence depends on who's looking over your shoulder

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    Adolescents have been shown to be particularly sensitive to peer influence. However, the data supporting these findings have been mostly limited to the impact of peers on risk-taking behaviours. Here, we investigated the influence of peers on performance of a high-level cognitive task (relational reasoning) during adolescence. We further assessed whether this effect on performance was dependent on the identity of the audience, either a friend (peer) or the experimenter (non-peer). We tested 24 younger adolescent (10.6–14.2 years), 20 older adolescent (14.9–17.8 years) and 20 adult (21.8–34.9 years) female participants. The presence of an audience affected adolescent, but not adult, relational reasoning performance. This audience effect on adolescent performance was influenced by the participants' age, task difficulty and the identity of the audience. These findings may have implications for education, where adolescents often do classwork or homework in the presence of others

    Defining predictors of responsiveness to advanced therapies in Crohn’s disease and ulcerative colitis: protocol for the IBD-RESPONSE and nested CD-metaRESPONSE prospective, multicentre, observational cohort study in precision medicine

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    Introduction: Characterised by chronic inflammation of the gastrointestinal tract, inflammatory bowel disease (IBD) symptoms including diarrhoea, abdominal pain and fatigue can significantly impact patient’s quality of life. Therapeutic developments in the last 20 years have revolutionised treatment. However, clinical trials and real-world data show primary non-response rates up to 40%. A significant challenge is an inability to predict which treatment will benefit individual patients. Current understanding of IBD pathogenesis implicates complex interactions between host genetics and the gut microbiome. Most cohorts studying the gut microbiota to date have been underpowered, examined single treatments and produced heterogeneous results. Lack of cross-treatment comparisons and well-powered independent replication cohorts hampers the ability to infer real-world utility of predictive signatures. IBD-RESPONSE will use multi-omic data to create a predictive tool for treatment response. Future patient benefit may include development of biomarker-based treatment stratification or manipulation of intestinal microbial targets. IBD-RESPONSE and downstream studies have the potential to improve quality of life, reduce patient risk and reduce expenditure on ineffective treatments. Methods and analysis: This prospective, multicentre, observational study will identify and validate a predictive model for response to advanced IBD therapies, incorporating gut microbiome, metabolome, single-cell transcriptome, human genome, dietary and clinical data. 1325 participants commencing advanced therapies will be recruited from ~40 UK sites. Data will be collected at baseline, week 14 and week 54. The primary outcome is week 14 clinical response. Secondary outcomes include clinical remission, loss of response in week 14 responders, corticosteroid-free response/remission, time to treatment escalation and change in patient-reported outcome measures. Ethics and dissemination: Ethical approval was obtained from the Wales Research Ethics Committee 5 (ref: 21/WA/0228). Recruitment is ongoing. Following study completion, results will be submitted for publication in peer-reviewed journals and presented at scientific meetings. Publications will be summarised at www.ibd-response.co.uk. Trial registration number: ISRCTN96296121

    Genome-wide transcriptomic analysis of the response to nitrogen limitation in Streptomyces coelicolor A3(2)

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    <p>Abstract</p> <p>Background</p> <p>The present study represents a genome-wide transcriptomic analysis of the response of the model streptomycete <it>Streptomyces coelicolor </it>A3(2) M145 to fermentor culture in Modified Evans Media limited, respectively, for nitrogen, phosphate and carbon undertaken as part of the ActinoGEN consortium to provide a publicly available reference microarray dataset.</p> <p>Findings</p> <p>A microarray dataset using samples from two replicate cultures for each nutrient limitation was generated. In this report our analysis has focused on the genes which are significantly differentially expressed, as determined by Rank Products Analysis, between samples from matched time points correlated by growth phase for the three pairs of differently limited culture datasets. With a few exceptions, genes are only significantly differentially expressed between the N6/N7 time points and their corresponding time points in the C and P-limited cultures, with the vast majority of the differentially expressed genes being more highly expressed in the N-limited cultures. Our analysis of these genes indicated expression of several members of the GlnR regulon are induced upon nitrogen limitation, as assayed for by [NH<sub>4</sub><sup>+</sup>] measurements, and we are able to identify several additional genes not present in the GlnR regulon whose expression is induced in response to nitrogen limitation. We also note SCO3327 which encodes a small protein (32 amino acid residues) unusually rich in the basic amino acids lysine (31.25%) and arginine (25%) is significantly differentially expressed in the nitrogen limited cultures. Additionally, we investigate the expression of known members of the GlnR regulon and the relationship between gene organization and expression for the SCO2486-SCO2487 and SCO5583-SCO5585 operons.</p> <p>Conclusions</p> <p>We provide a list of genes whose expression is differentially expressed in low nitrogen culture conditions, including a putative nitrogen storage protein encoded by SCO3327. Our list includes several genes whose expression patterns are similar to up-regulated members of the GlnR regulon and are induced in response to nitrogen limitation. These genes represent likely targets for future studies into the nitrogen starvation response in <it>Streptomyces coelicolor</it>.</p

    Development of a UK core dataset for geriatric medicine research: : a position statement and results from a Delphi consensus process

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    Funding AS and MW are funded by the Newcastle National Institute for Health (NIHR) Biomedical Research Centre, which also funded the initial meeting of academic clinicians in geriatric medicine during the Delphi process. The views expressed in this article are those of the authors and not necessarily those of the NIHR, the NHS, or the Department of Health. Acknowledgements The authors acknowledge the contributions of members of the UK Geriatric Medicine Core Dataset Extended Working Group.Peer reviewedPublisher PD
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