The repeat FIT (RFIT) study:Does repeating faecal immunochemical tests provide reassurance and improve colorectal cancer detection?

AimFaecal immunochemical tests (FIT) are highly sensitive for colorectal cancer (CRC) detection. Little evidence exists regarding repeat FIT. The repeat FIT (RFIT) study aimed to determine whether second and third FIT provide reassurance and improve CRC or significant bowel disease (SBD) identification.MethodsThis was a prospective observational study. Patients recruited from urgent referrals returned three FIT and underwent colonoscopy. Chi-square tests compared categorical data. Diagnostic accuracy variables (sensitivity/specificity/positive predictive value [PPV]/negative predictive value [NPV]) were calculated for one, two and three FIT (95% CI). Three negative FIT (<10 μg Hb/g of faeces [μg/g]) groups (one, two, three) were compared with positive groups (one or more FIT ≥10 μg/g). CRC and SBD detection rates were compared by strategy.ResultsA total of 460 patients (mean age: 66.8 years, 233 males and 227 females, 23 CRC, 80 SBD) were included in the study. For one, two and three negative FIT, CRC sensitivity remained static (95.7%); specificity (44.6%, 40.7% and 38.4%) and NPV decreased (99.5%, 99.4% and 99.4%). For SBD, sensitivity increased (78.8%, 83.8% and 86.3%), specificity decreased (47.4%, 43.7% and 41.6%) and NPV increased (91.4%, 92.7% and 93.5%). In one, two and three positive FIT groups, CRC detection was 8.3%,16.1% and 20.9%. CRC mean FIT was 150 μg/g, <6 μg/g for benign pathology.ConclusionsOne or more negative FIT increases the sensitivity for CRC/SBD. Repeating FIT provides greater differentiation of patients with and without CRC/SBD compared to single FIT but is associated with decreased specificity and PPV. Multiple negative FIT may offer reassurance; however, application of repeating FIT may be restricted given the associated increase in investigations S1

Spider Optimization: Probing the Systematics of a Large Scale B-Mode Experiment

Spider is a long-duration, balloon-borne polarimeter designed to measure large scale Cosmic Microwave Background (CMB) polarization with very high sensitivity and control of systematics. The instrument will map over half the sky with degree angular resolution in I, Q and U Stokes parameters, in four frequency bands from 96 to 275 GHz. Spider's ultimate goal is to detect the primordial gravity wave signal imprinted on the CMB B-mode polarization. One of the challenges in achieving this goal is the minimization of the contamination of B-modes by systematic effects. This paper explores a number of instrument systematics and observing strategies in order to optimize B-mode sensitivity. This is done by injecting realistic-amplitude, time-varying systematics in a set of simulated time-streams. Tests of the impact of detector noise characteristics, pointing jitter, payload pendulations, polarization angle offsets, beam systematics and receiver gain drifts are shown. Spider's default observing strategy is to spin continuously in azimuth, with polarization modulation achieved by either a rapidly spinning half-wave plate or a rapidly spinning gondola and a slowly stepped half-wave plate. Although the latter is more susceptible to systematics, results shown here indicate that either mode of operation can be used by Spider.Comment: 15 pages, 12 figs, version with full resolution figs available here http://www.astro.caltech.edu/~lgg/spider_front.ht

Could Postnatal Women's Groups Be Used to Improve Outcomes for Mothers and Children in High-Income Countries? A Systematic Review

Introduction Participatory postnatal women's groups have been shown to have a significant impact on maternal and neonatal mortality in low-income countries. However, it is not clear whether this approach can be translated to high-income countries (HICs). We conducted a systematic review to answer the question: "Can postnatal women's groups improve health outcomes for mothers and children in high-income countries?" Methods MEDLINE, EMBASE and Cochrane databases were searched for randomised controlled trials testing any group-based intervention during the postnatal period, in HICs. No limitations were applied to stated outcomes. Results Nine trials, including 3029 women, fulfilled the criteria. Group-based interventions, facilitated by health professionals, ranged from didactic to participant-led. Three trials addressed postnatal depression, one addressed physical activity, whilst the remainder looked at multiple health or social outcomes. Three trials reported a significant association between their intervention and at least one outcome measure. Study limitations included poor and inequitable intervention uptake, low participant retention, small sample size and incomplete intervention description. Discussion This review found limited and incompletely described evidence testing the use of postnatal group-based interventions to improve health outcomes in HICs. Promising results were reported when the obstacles of sample size and group attendance were overcome. Studies reporting positive impacts on primary outcomes reported higher attendance rates and involved a psychoeducational or cognitive behavioural component in their group approaches. Further research should design and evaluate implementation strategies, assess the use of lay support workers in community settings to improve attendance and retention, and examine the effect of the group environment on outcomes

Mummified precocial bird wings in mid-Cretaceous Burmese amber

Our knowledge of Cretaceous plumage is limited by the fossil record itself: compression fossils surrounding skeletons lack the finest morphological details and seldom preserve visible traces of colour, while discoveries in amber have been disassociated from their source animals. Here we report the osteology, plumage and pterylosis of two exceptionally preserved theropod wings from Burmese amber, with vestiges of soft tissues. The extremely small size and osteological development of the wings, combined with their digit proportions, strongly suggests that the remains represent precocial hatchlings of enantiornithine birds. These specimens demonstrate that the plumage types associated with modern birds were present within single individuals of Enantiornithes by the Cenomanian (99 million years ago), providing insights into plumage arrangement and microstructure alongside immature skeletal remains. This finding brings new detail to our understanding of infrequently preserved juveniles, including the first concrete examples of follicles, feather tracts and apteria in Cretaceous avialans

Investigation of an optically induced superstrate plasma for tuning microstrip antennas

Optically induced electron-hole plasmas in silicon are used to perform radiation pattern tuning. The antenna is a slot loaded microstrip patch and the effect of illumination is shown to produce beam switching in the radiation patterns of certain modes while other modes are left unaffected. The structure is specifically designed to make the best use of currently available miniature laser sources to form a compact tunable package. Modelled and measured results for tuning of the radiation patterns and frequency response are presented. The effect of the losses incurred by the plasma along with the losses in the optically transparent ground plane are quantified in both simulation and measurement. This forms the basis for designing other types of optically tunable miniature antennas based on the structure presented

Concurrent codes:a holographic-type encoding robust against noise and loss

Concurrent coding is an encoding scheme with 'holographic' type properties that are shown here to be robust against a significant amount of noise and signal loss. This single encoding scheme is able to correct for random errors and burst errors simultaneously, but does not rely on cyclic codes. A simple and practical scheme has been tested that displays perfect decoding when the signal to noise ratio is of order -18dB. The same scheme also displays perfect reconstruction when a contiguous block of 40% of the transmission is missing. In addition this scheme is 50% more efficient in terms of transmitted power requirements than equivalent cyclic codes. A simple model is presented that describes the process of decoding and can determine the computational load that would be expected, as well as describing the critical levels of noise and missing data at which false messages begin to be generated

Predicting mental imagery based BCI performance from personality, cognitive profile and neurophysiological patterns

Mental-Imagery based Brain-Computer Interfaces (MI-BCIs) allow their users to send commands to a computer using their brain-activity alone (typically measured by ElectroEncephaloGraphy— EEG), which is processed while they perform specific mental tasks. While very promising, MI-BCIs remain barely used outside laboratories because of the difficulty encountered by users to control them. Indeed, although some users obtain good control performances after training, a substantial proportion remains unable to reliably control an MI-BCI. This huge variability in user-performance led the community to look for predictors of MI-BCI control ability. However, these predictors were only explored for motor-imagery based BCIs, and mostly for a single training session per subject. In this study, 18 participants were instructed to learn to control an EEG-based MI-BCI by performing 3 MI-tasks, 2 of which were non-motor tasks, across 6 training sessions, on 6 different days. Relationships between the participants’ BCI control performances and their personality, cognitive profile and neurophysiological markers were explored. While no relevant relationships with neurophysiological markers were found, strong correlations between MI-BCI performances and mental-rotation scores (reflecting spatial abilities) were revealed. Also, a predictive model of MI-BCI performance based on psychometric questionnaire scores was proposed. A leave-one-subject-out cross validation process revealed the stability and reliability of this model: it enabled to predict participants’ performance with a mean error of less than 3 points. This study determined how users’ profiles impact their MI-BCI control ability and thus clears the way for designing novel MI-BCI training protocols, adapted to the profile of each user

Systematic review of studies generating individual participant data on the efficacy of drugs for treating soil-transmitted helminthiases and the case for data-sharing

Preventive chemotherapy and transmission control (PCT) by mass drug administration is the cornerstone of the World Health Organization (WHO)’s policy to control soil-transmitted helminthiases (STHs) caused by Ascaris lumbricoides (roundworm), Trichuris trichiura (whipworm) and hookworm species (Necator americanus and Ancylostama duodenale) which affect over 1 billion people globally. Despite consensus that drug efficacies should be monitored for signs of decline that could jeopardise the effectiveness of PCT, systematic monitoring and evaluation is seldom implemented. Drug trials mostly report aggregate efficacies in groups of participants, but heterogeneities in design complicate classical meta-analyses of these data. Individual participant data (IPD) permit more detailed analysis of drug efficacies, offering increased sensitivity to identify atypical responses potentially caused by emerging drug resistance