Doing New Research? Don't Forget the Old

Nobody should do a new research study, says Clarke, without first systematically reviewing the literature. And journal editors should insist that all research papers are accompanied by an up-to-date systematic revie

The limits of spatial resolution achievable using a 30kHz multibeam sonar: model predictions and field results

A Simrad EM300 multibeam sonar was used to attempt to resolve small (-5m high) targets in 450m of water. The targets had previously been surveyed using a deeply towed 59 kHz sidescan sonar. Using multisector active yaw, pitch and roll compensation, together with dynamically altering angular sectors, the sonar is capable of maintaining sounding densities of as tight as 10m spacing in these water depths. This is significantly smaller than the largest dimension of the projected beam footprints (1 6-64m). The observed data suggest that the targets are intermittently resolved. The field results compare well to the output of a numerical model which reproduces the imaging geometry. Possible variations in the imaging geometry are implemented in the model, comparing equiangular and equidistant beam spacings, differing angular sectors and all the different combinations of transmit and receive beam widths that are available for this model of sonar. While amplitude detection is significantly aliased by targets smaller than the across track beam footprint, under conditions where the signal to noise ratio is favorable, phase detection can be used to reduce the minimum size of target observed to about the scale of the across track beam width. Thus having the beam spacing at the scale is justifiable. The phase distortion due to smaller targets, however, is generally averaged out

Core outcome sets and systematic reviews

Systematic reviews seek to bring together research evidence to answer the question for the review. The reviewers usually wish to compare, contrast and, if appropriate, combine the findings of the existing research studies. However, these intentions are often thwarted by inconsistencies in the outcomes that were measured and reported in the individual studies. This, in turn, makes it difficult for readers of the review to use it to make informed decisions and choices about health and social care. One solution is for trials in a particular topic area to measure and report a standardised set of outcomes, which would then be used in the review. Core outcome sets are a means of doing this, providing an agreed standardised collection of outcomes for measuring and reporting for a specific area of health. In this commentary, we argue for greater involvement of systematic reviewers in the development and implementation of core outcome sets. This might help with, for example, the selection of outcomes to include in the Summary of findings tables that provide users of the review with the key quantitative findings. Consideration of core outcome sets when reviewers register their topics with Cochrane Review Groups or in PROSPERO would also help reviewers to plan their reviews. A greater uptake of core outcome sets across research, including systematic reviews, would help towards the ultimate aim of improving health and well-being through improving health and social care

Effects on patients of their healthcare practitioner's or institution's participation in clinical trials: A systematic review

Background: Systematic reviews have shown uncertainty about the size or direction of any 'trial effect' for patients in trials compared to those treated outside trials. We are not aware of any systematic review of whether there is a 'trial effect' related to being treated by healthcare practitioners or institutions that take part in research.  Methods: We searched the Cochrane Methodology Register and MEDLINE (most recently in January 2009) for studies in which patients were allocated to treatment in one or other setting, and cohort studies reporting the outcomes of patients from different settings. We independently assessed study quality, including the control of bias in the generation of the comparison groups, and extracted data.  Results: We retrieved and checked more than 15,000 records. Thirteen articles were eligible: five practitioner studies and eight institution studies. Meta-analyses were not possible because of heterogeneity. Two practitioner studies were judged to be 'controlled' or better. A Canadian study among nurses found that use of research evidence was higher for those who took part in research working groups and a Danish study on general practitioners found that trial doctors were more likely to prescribe in accordance with research evidence and guidelines. Five institution studies were 'controlled' but provided mixed results. A study of North American patients at hospitals that had taken part in trials for myocardial infarction found no statistically significant difference in treatment for patients in trial and non-trial hospitals. A Canadian study of myocardial infarction patients found that trial participants had better survival than patients in the same hospitals who were not in trials or those in non-trial hospitals. A study of general practices in Denmark did not detect differences in guideline adherence between trial and non-trial practices but found that trial practices were more likely to prescribe the trial sponsor's drugs. The other two 'controlled' studies of institutions found lower mortality in trial than non-trial hospitals.  Conclusions: The available findings from existing research suggest that there might be a 'trial effect' of better outcomes, greater adherence to guidelines and more use of evidence by practitioners and institutions that take part in trials. However, the consequences for patient health are uncertain and the most robust conclusion may be that there is no apparent evidence that patients treated by practitioners or in institutions that take part in trials do worse than those treated elsewhere

Side Scan Versus Multibeam Echosounder Object Detection: A Comparative Analysis

The undisputed remote sensing tool for detailed sea floor object detection is the side scan sonar. From pipelines, to downed aircraft, to mines, a side scan sonar’s unique characteristics effectively ensonify and subsequently display these objects. For bathymetry, the Multibeam Echosounder (MBES) has quickly proven its superior capabilities. An MBES’s unique characteristics allow it to provide 100 per cent ensonification of the sea floor while meeting or even exceeding IHO specifications. During the 1997 Coastal Multibeam Sonar Training Course in Victoria, BC, inert mines were laid at different depths and then ensonified by a side scan sonar and an MBES. The aim of this exercise was to compare the detection characteristics of the two sonars using one of the inert mines. This paper is a discussion of that comparison and the lessons learned. Comparative imagery is used to illustrate the success of each sonar in illuminating the mines to the operator. Unaided visual detection is not always the most efficient method for finding objects in large quantities of MBES data; therefore, subtractive temporal analysis was implemented in order to enhance the MBES object detection process. As well, a simple automated detection algorithm was used successfully on the temporally differenced images. The background, implementation and results of the MBES subtractive analysis performed in the area of the inert mine will be compared to the detection achieved using the side scan sonar. Finally, conclusions will be drawn as to the efficacy of the MBES as an object detection sonar

Learning from Cochrane systematic reviews: what improvements do these suggest for the design of trials?

Grant information: The study was funded by the Health Research Board (grant ‘Capacity Building for Evidence Synthesis – Evidence Synthesis Ireland 2018’) as part of Trial Forge (http://trialforge.org), a non-commercial research initiative led by ST. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

RIVPACS database documentation. Final report

With the advent of the EU Water Framework Directive the concept of the 'reference condition' has become explicit within the legislative framework of the European Union. Reference condition has been established as a quality standard against which assessments of biological degradation must be compared. It is therefore essential that Member States can demonstrate that the biological datasets used to define their reference conditions meet the criteria of the WFD. The RIVPACS reference site dataset is therefore central to the definition of reference conditions for macroinvertebrates in streams and rivers in the United Kingdom. Objectives of research: • To establish the ownership of the RIVPACS reference site dataset • To liaise with all stakeholders of the dataset to establish unhindered access to the RIVPACS reference site dataset for the UK agencies (in perpetuity) • To deliver the RIVPACS reference site dataset to the UK agencies and to the public domain in a readily accessible database together will its accompanying physicochemical variables (both existing and newly collated as part of this project), historical and current anthropogenic stress data, and a range of calculated biotic indices. Key findings and recommendations: Ownership of the RIVPACS dataset resides with no single organization and several different organizations consider that they own different portions of the dataset. Formal permissions to release the dataset into the public domain have been obtained from all twelve extant organizations that have been identified as having funded various phases of RIVPACS research. In addition, CEH/NERC has also agreed to release the RIVPACS dataset to the public domain. Terms and conditions relating to the end use of the RIVPACS dataset have now been established. The RIVPACS database has been assembled in Microsoft® Access and can now be downloaded from the CEH web site. This report details the terms and conditions that apply to all end users of the database and it documents the tables given in the database, their structure and the origin of their data. A separate Pressure Data Analysis report describes the screening of the RIVPACS sites in terms of the current and emerging definitions of reference condition

Data handling methods and target detection results for multibeam and sidescan data collected as part of the search for SwissAir Flight 111

The crash of SwissAir Flight 111, off Nova Scotia in September 1998, triggered one of the largest seabed search surveys in Canadian history. The primary search tools used were sidescan sonars (both conventional and focussed types) and multibeam sonars. The processed search data needed to be distributed on a daily basis to other elements of the fleet for precise location of divers and other optical seabed search instruments (including laser linescan and ROV video). As a result of the glacial history of the region, many natural targets, similar in gross nature to aircraft debris were present. These included widespread linear bedrock outcrop patterns together with near ubiquitous glacial erratic boulders. Because of the severely broken-up nature of the remaining aircraft debris, sidescan imaging alone was often insufficient to unambiguously identify targets. The complementary attributes of higher resolution, but poorly located, sidescan imagery together with slightly lower resolution, but excellently navigated multibeam sonar proved to be one of critical factors in the success of the search. It proved necessary to rely heavily on the regional context of the seabed (provided by the multibeam sonar bathymetry and backscatter imagery) to separate natural geomorphic targets from anomalous anthropogenic debris. In order to confidently prove or disprove a potential target, the interpreter required simultaneous access to the full resolution sidescan data in the geographic context of the multibeam framework. Specific software tools had to be adapted or developed shipboard to provide this capability. Whilst developed specifically for this application, these survey tools can provide improved processing speed and confidence as part of more general mine hunting, hydrographic, engineering or scientific surveys

Predicting breastfeeding in women living in areas of economic hardship : explanatory role of the theory of planned behaviour

This study employed the theory of planned behaviour (TPB) and additional variables (descriptive norm, moral norm, self-identity) to investigate the factors underlying breastfeeding intention and subsequent breastfeeding at four time points (during hospital stay, at hospital discharge, 10 days postpartum and 6 weeks postpartum) in a sample of women selected from defined areas of economic hardship (N = 248). A model containing the TPB, additional variables and demographic factors provided a good prediction of both intention (R-2 = 0.72; attitude, perceived behavioural control, moral norm and self-identity significant predictors) and behaviour - breastfeeding at birth (88.6% correctly classified; household deprivation, intention, attitude significant), at discharge from hospital (87.3% correctly classified; intention, attitude significant), 10 days after discharge (83.1% correctly classified; education, intention, attitude, descriptive norm significant) and 6 weeks after discharge (78.0% correctly classified; age, household deprivation, ethnicity, moral norm significant). Implications for interventions are discussed, such as the potential usefulness of targeting descriptive norms, moral norms and perceived behavioural control (PBC) when attempting to increase breastfeeding uptake