1,816 research outputs found

    Flanker interference at both stimulus and response levels decreases with age

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    When trying to identify the colour of a target, people's performance is impaired by nearby distractors of different colours. It is controversial whether these interference effects originate from competing stimuli, competing responses or from both simultaneously. These interference effects may also differ depending on a person's age. Comparisons between studies show mixed results, while differences in experimental design and data analysis complicate the interpretation. In our study, we manipulated the relative proportions of congruent and incongruent trials with respect to both stimuli and responses. Considering this aspect, we asked whether people resolve stimulus and response interference differently at different ages. 92 children (6-14 years), 25 young adults (20-43 years) and 33 older adults (60-84 years) performed a coloured version of the Eriksen flanker task. Since reaction times and errors were correlated, inverse efficiency scores were used to address speed-accuracy trade-offs between groups. Absolute interference effects were used to measure relationships with age. The results showed first, unexpectedly, that response interference was comparable between stimulus- and response-balanced conditions. Second, performance at all ages was significantly influenced both by competing stimuli and responses. Most importantly, the size of interference effects decreased with age. These findings cast some doubt on the conclusions of previous studies, and raise further questions about how cognitive control is best measured across the lifespan.</p

    Microbiologic follow-up study in adult bronchiectasis

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    SummaryThere is minimal published longitudinal data about pathogenic microorganisms in adults with bronchiectasis. Therefore a study was undertaken to assess the microbiologic profile over time in bronchiectasis.A prospective study of clinical and microbiologic outcomes was performed. Subjects were assessed by a respiratory physician and sputum sample were collected for analysis. Subjects were followed up and had repeat assessment performed.Eighty-nine subjects were followed up for a period of 5.7±3.6 years. On initial assessment the two most common pathogens isolated were Haemophilus influenzae (47%) and Pseudomonas aeruginosa (12%) whilst 21% had no pathogens isolated. On follow-up review results were similar (40% H. influenzae, 18% P. aeruginosa and 26% no pathogens). The prevalence of antibiotic resistance of isolates increased from 13% to 30%. Analysis of a series of H. influenzae isolates showed they were nearly all nontypeable and all were different subtypes. Subjects with no pathogens isolated from their sputum had the mildest disease, while subjects with P. aeruginosa had the most severe bronchiectasis.Many subjects with bronchiectasis are colonized with the same bacterium over an average follow-up of 5 years. Different pathogens are associated with different patterns of clinical disease

    Leapfrogging laboratories: the promise and pitfalls of high-tech solutions for antimicrobial resistance surveillance in low-income settings.

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    The scope and trajectory of today's escalating antimicrobial resistance (AMR) crisis is inadequately captured by existing surveillance systems, particularly those of lower income settings. AMR surveillance systems typically collate data from routine culture and susceptibility testing performed in diagnostic bacteriology laboratories to support healthcare. Limited access to high quality culture and susceptibility testing results in the dearth of AMR surveillance data, typical of many parts of the world where the infectious disease burden and antimicrobial need are high. Culture and susceptibility testing by traditional techniques is also slow, which limits its value in infection management. Here, we outline hurdles to effective resistance surveillance in many low-income settings and encourage an open attitude towards new and evolving technologies that, if adopted, could close resistance surveillance gaps. Emerging advancements in point-of-care testing, laboratory detection of resistance through or without culture, and in data handling, have the potential to generate resistance data from previously unrepresented locales while simultaneously supporting healthcare. Among them are microfluidic, nucleic acid amplification technology and next-generation sequencing approaches. Other low tech or as yet unidentified innovations could also rapidly accelerate AMR surveillance. Parallel advances in data handling further promise to significantly improve AMR surveillance, and new frameworks that can capture, collate and use alternate data formats may need to be developed. We outline the promise and limitations of such technologies, their potential to leapfrog surveillance over currently available, conventional technologies in use today and early steps that health systems could take towards preparing to adopt them

    Do sounds near the hand facilitate tactile reaction times? Four experiments and a meta-analysis provide mixed support and suggest a small effect-size

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    The brain represents the space immediately surrounding the body differently to more distant parts of space. Direct evidence for this ‘peripersonal space’ representation comes from neurophysiological studies in monkeys, which show distance-dependent responses to visual stimuli in neurons with spatially-coincident tactile responses. Most evidence for peripersonal space in humans is indirect: spatial- and distance-dependent modulations of reaction times and error rates in behavioural tasks. In one task often used to assess peripersonal space, sounds near the body have been argued to speed reactions to tactile stimuli. We conducted four experiments attempting to measure this distance-dependent audio-tactile interaction. We found no distance-dependent enhancement of tactile processing in error rates or task performance, but found some evidence for a general speeding of reaction times by 9.5ms when sounds were presented near the hand. Systematic review revealed an over-estimation of reported effect-sizes, lack of control conditions, a wide variety of methods, post-hoc removal of data, and flexible methods of data analysis. After correcting for the speed of sound, removing biased or inconclusive studies, correcting for temporal expectancy, and using the trim-and-fill method to correct for publication bias, meta-analysis revealed an overall benefit of 15.2ms when tactile stimuli are accompanied by near sounds compared to sounds further away. While this effect may be due to peripersonal space, response probability and the number of trials per condition explained significant proportions of variance in this near versus far benefit. These confounds need to be addressed, and alternative explanations ruled out by future, ideally pre-registered, studies

    Elevated levels of inflammatory cytokines predict survival in idiopathic and familial pulmonary arterial hypertension

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    BACKGROUND: Inflammation is a feature of pulmonary arterial hypertension (PAH), and increased circulating levels of cytokines are reported in patients with PAH. However, to date, no information exists on the significance of elevated cytokines or their potential as biomarkers. We sought to determine the levels of a range of cytokines in PAH and to examine their impact on survival and relationship to hemodynamic indexes. METHODS AND RESULTS: We measured levels of serum cytokines (tumor necrosis factor-alpha, interferon-gamma and interleukin-1beta, -2, -4, -5, -6, -8, -10, -12p70, and -13) using ELISAs in idiopathic and heritable PAH patients (n=60). Concurrent clinical data included hemodynamics, 6-minute walk distance, and survival time from sampling to death or transplantation. Healthy volunteers served as control subjects (n=21). PAH patients had significantly higher levels of interleukin-1beta, -2, -4, -6, -8, -10, and -12p70 and tumor necrosis factor-alpha compared with healthy control subjects. Kaplan-Meier analysis showed that levels of interleukin-6, 8, 10, and 12p70 predicted survival in patients. For example, 5-year survival with interleukin-6 levels of >9 pg/mL was 30% compared with 63% for patients with levels < or = 9 pg/mL (P=0.008). In this PAH cohort, cytokine levels were superior to traditional markers of prognosis such as 6-minute walk distance and hemodynamics. CONCLUSIONS: This study illustrates dysregulation of a broad range of inflammatory mediators in idiopathic and familial PAH and demonstrates that cytokine levels have a previously unrecognized impact on patient survival. They may prove to be useful biomarkers and provide insight into the contribution of inflammation in PAH

    Guidelines for Assessment and Instruction in Statistics Education (GAISE) College Report 2016

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    In 2005 the American Statistical Association (ASA) endorsed the Guidelines for Assessment and Instruction in Statistics Education (GAISE) College Report. This report has had a profound impact on the teaching of introductory statistics in two- and four-year institutions, and the six recommendations put forward in the report have stood the test of time. Much has happened within the statistics education community and beyond in the intervening 10 years, making it critical to re-evaluate and update this important report. For readers who are unfamiliar with the original GAISE College Report or who are new to the statistics education community, the full version of the 2005 report can be found at http://www.amstat.org/education/gaise/GaiseCollege_full.pdf and a brief history of statistics education can be found in Appendix A of this new report. The revised GAISE College Report takes into account the many changes in the world of statistics education and statistical practice since 2005 and suggests a direction for the future of introductory statistics courses. Our work has been informed by outreach to the statistics education community and by reference to the statistics education literature

    Drunk bugs: chronic vapour alcohol exposure induces marked changes in the gut microbiome in mice

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    The gut microbiota includes a community of bacteria that play an integral part in host health and biological processes. Pronounced and repeated findings have linked gut microbiome to stress, anxiety, and depression. Currently, however, there remains only a limited set of studies focusing on microbiota change in substance abuse, including alcohol use disorder. To date, no studies have investigated the impact of vapour alcohol administration on the gut microbiome. For research on gut microbiota and addiction to proceed, an understanding of how route of drug administration affects gut microbiota must first be established. Animal models of alcohol abuse have proven valuable for elucidating the biological processes involved in addiction and alcohol-related diseases. This is the first study to investigate the effect of vapour route of ethanol administration on gut microbiota in mice. Adult male C57BL/6J mice were exposed to 4 weeks of chronic intermittent vapourized ethanol (CIE, N = 10) or air (Control, N = 9). Faecal samples were collected at the end of exposure followed by 16S sequencing and bioinformatic analysis. Robust separation between CIE and Control was seen in the microbiome, as assessed by alpha (p < 0.05) and beta (p < 0.001) diversity, with a notable decrease in alpha diversity in CIE. These results demonstrate that CIE exposure markedly alters the gut microbiota in mice. Significant increases in genus Alistipes (p < 0.001) and significant reductions in genra Clostridium IV and XIVb (p < 0.001), Dorea (p < 0.01), and Coprococcus (p < 0.01) were seen between CIE mice and Control. These findings support the viability of the CIE method for studies investigating the microbiota-gut-brain axis and align with previous research showing similar microbiota alterations in inflammatory states during alcoholic hepatitis and psychological stress

    Locating primary somatosensory cortex in human brain stimulation studies: Experimental evidence

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    Transcranial magnetic stimulation (TMS) over human primary somatosensory cortex (S1) does not produce immediate outputs. Researchers must therefore rely on indirect methods for TMS coil positioning. The 'gold standard' is to use individual functional and structural magnetic resonance imaging (MRI) data, but the majority of studies don't do this. The most common method to locate the hand area of S1 (S1-hand) is to move the coil posteriorly from the hand area of primary motor cortex (M1-hand). Yet, S1-hand is not directly posterior to M1-hand. We localised the index finger area of S1-hand experimentally in four ways. First, we re-analysed functional MRI data from 20 participants who received vibrotactile stimulation to their 10 digits. Second, to assist the localisation of S1-hand without MRI data, we constructed a probabilistic atlas of the central sulcus from 100 healthy adult MRIs, and measured the likely scalp location of S1-index. Third, we conducted two experiments mapping the effects of TMS across the scalp on tactile discrimination performance. Fourth, we examined all available neuronavigation data from our laboratory on the scalp location of S1-index. Contrary to the prevailing method, and consistent with systematic review evidence, S1-index is close to the C3/C4 electroencephalography (EEG) electrode locations on the scalp, approximately 7-8 cm lateral to the vertex, and approximately 2 cm lateral and 0.5 cm posterior to the M1-FDI scalp location. These results suggest that an immediate revision to the most commonly-used heuristic to locate S1-hand is 45 required. The results of many TMS studies of S1-hand need reassessment

    A One Health Study of the Genetic Relatedness of Klebsiella pneumoniae and Their Mobile Elements in the East of England.

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    BACKGROUND: Klebsiella pneumoniae is a human, animal, and environmental commensal and a leading cause of nosocomial infections, which are often caused by multiresistant strains. We evaluate putative sources of K. pneumoniae that are carried by and infect hospital patients. METHODS: We conducted a 6-month survey on 2 hematology wards at Addenbrooke's Hospital, Cambridge, United Kingdom, in 2015 to isolate K. pneumoniae from stool, blood, and the environment. We conducted cross-sectional surveys of K. pneumoniae from 29 livestock farms, 97 meat products, the hospital sewer, and 20 municipal wastewater treatment plants in the East of England between 2014 and 2015. Isolates were sequenced and their genomes compared. RESULTS: Klebsiella pneumoniae was isolated from stool of 17/149 (11%) patients and 18/922 swabs of their environment, together with 1 bloodstream infection during the study and 4 others over a 24-month period. Each patient carried 1 or more lineages that was unique to them, but 2 broad environmental contamination events and patient-environment transmission were identified. Klebsiella pneumoniae was isolated from cattle, poultry, hospital sewage, and 12/20 wastewater treatment plants. There was low genetic relatedness between isolates from patients/their hospital environment vs isolates from elsewhere. Identical genes encoding cephalosporin resistance were carried by isolates from humans/environment and elsewhere but were carried on different plasmids. CONCLUSION: We identified no patient-to-patient transmission and no evidence for livestock as a source of K. pneumoniae infecting humans. However, our findings reaffirm the importance of the hospital environment as a source of K. pneumoniae associated with serious human infection
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