The role of peripheral vision in the flashed face distortion effect

The flashed face distortion effect is a phenomenon whereby images of faces, presented at 4–5 Hz in the visual periphery, appear distorted. It has been hypothesized that the effect is driven by cortical, rather than retinal, components. Here, we investigated the role of peripheral viewing on the effect. Normally sighted participants viewed the stimulus peripherally, centrally, and centrally with a blurring lens (to match visual acuity in the peripheral location). Participants rated the level of distortion using a Visual Analogue Scale. Although optical defocus did have a significant effect on distortion ratings, peripheral viewing had a much greater effect, despite matched visual acuity. We suggest three potential mechanisms for this finding: increased positional uncertainty in the periphery, reduced deployment of attention to the visual periphery, or the visual crowding effect

Costs and staffing resource requirements for adaptive clinical trials: quantitative and qualitative results from the Costing Adaptive Trials project.

BACKGROUND: Adaptive designs offer great promise in improving the efficiency and patient-benefit of clinical trials. An important barrier to further increased use is a lack of understanding about which additional resources are required to conduct a high-quality adaptive clinical trial, compared to a traditional fixed design. The Costing Adaptive Trials (CAT) project investigated which additional resources may be required to support adaptive trials. METHODS: We conducted a mock costing exercise amongst seven Clinical Trials Units (CTUs) in the UK. Five scenarios were developed, derived from funded clinical trials, where a non-adaptive version and an adaptive version were described. Each scenario represented a different type of adaptive design. CTU staff were asked to provide the costs and staff time they estimated would be needed to support the trial, categorised into specified areas (e.g. statistics, data management, trial management). This was calculated separately for the non-adaptive and adaptive version of the trial, allowing paired comparisons. Interviews with 10 CTU staff who had completed the costing exercise were conducted by qualitative researchers to explore reasons for similarities and differences. RESULTS: Estimated resources associated with conducting an adaptive trial were always (moderately) higher than for the non-adaptive equivalent. The median increase was between 2 and 4% for all scenarios, except for sample size re-estimation which was 26.5% (as the adaptive design could lead to a lengthened study period). The highest increase was for statistical staff, with lower increases for data management and trial management staff. The percentage increase in resources varied across different CTUs. The interviews identified possible explanations for differences, including (1) experience in adaptive trials, (2) the complexity of the non-adaptive and adaptive design, and (3) the extent of non-trial specific core infrastructure funding the CTU had. CONCLUSIONS: This work sheds light on additional resources required to adequately support a high-quality adaptive trial. The percentage increase in costs for supporting an adaptive trial was generally modest and should not be a barrier to adaptive designs being cost-effective to use in practice. Informed by the results of this research, guidance for investigators and funders will be developed on appropriately resourcing adaptive trials

Buffy coat specimens remain viable as a DNA source for highly multiplexed genome-wide genetic tests after long term storage

<p>Abstract</p> <p>Background</p> <p>Blood specimen collection at an early study visit is often included in observational studies or clinical trials for analysis of secondary outcome biomarkers. A common protocol is to store buffy coat specimens for future DNA isolation and these may remain in frozen storage for many years. It is uncertain if the DNA remains suitable for modern genome wide association (GWA) genotyping.</p> <p>Methods</p> <p>We isolated DNA from 120 Action to Control Cardiovascular Risk in Diabetes (ACCORD) clinical trial buffy coats sampling a range of storage times up to 9 years and other factors that could influence DNA yield. We performed TaqMan SNP and GWA genotyping to test whether the DNA retained integrity for high quality genetic analysis.</p> <p>Results</p> <p>We tested two QIAGEN automated protocols for DNA isolation, preferring the Compromised Blood Protocol despite similar yields. We isolated DNA from all 120 specimens (yield range 1.1-312 ug per 8.5 ml ACD tube of whole blood) with only 3/120 samples yielding < 10 ug DNA. Age of participant at blood draw was negatively associated with yield (mean change -2.1 ug/year). DNA quality was very good based on gel electrophoresis QC, TaqMan genotyping of 6 SNPs (genotyping no-call rate 1.1% in 702 genotypes), and excellent quality GWA genotyping data (maximum per sample genotype missing rate 0.64%).</p> <p>Conclusions</p> <p>When collected as a long term clinical trial or biobank specimen for DNA, buffy coats can be stored for up to 9 years in a -80degC frozen state and still produce high yields of DNA suitable for GWA analysis and other genetic testing.</p> <p>Trial Registration</p> <p>The Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial is registered with ClinicalTrials.gov, number <a href="http://www.clinicaltrials.gov/ct2/show/NCT00000620">NCT00000620</a>.</p

Overground walking speed changes when subjected to body weight support conditions for nonimpaired and post stroke individuals

<p>Abstract</p> <p>Background</p> <p>Previous research has shown that body weight support (BWS) has the potential to improve gait speed for individuals post-stroke. However, body weight support also reduces the optimal walking speed at which energy use is minimized over the gait cycle indicating that BWS should reduce walking speed capability.</p> <p>Methods</p> <p>Nonimpaired subjects and subjects post-stroke walked at a self-selected speed over a 15 m walkway. Body weight support (BWS) was provided to subjects at 0%, 10%, 20%, 30%, and 40% of the subject's weight while they walked overground using a robotic body weight support system. Gait speed, cadence, and average step length were calculated for each subject using recorded data on their time to walk 10 m and the number of steps taken.</p> <p>Results</p> <p>When subjected to greater levels of BWS, self-selected walking speed decreased for the nonimpaired subjects. However, subjects post-stroke showed an average increase of 17% in self-selected walking speed when subjected to some level of BWS compared to the 0% BWS condition. Most subjects showed this increase at the 10% BWS level. Gait speed increases corresponded to an increase in step length, but not cadence.</p> <p>Conclusions</p> <p>The BWS training environment results in decreased self-selected walking speed in nonimpaired individuals, however self-selected overground walking speed is facilitated when provided with a small percentage of body weight support for people post-stroke.</p

Increasing frailty is associated with higher prevalence and reduced recognition of delirium in older hospitalised inpatients: results of a multi-centre study

Purpose: Delirium is a neuropsychiatric disorder delineated by an acute change in cognition, attention, and consciousness. It is common, particularly in older adults, but poorly recognised. Frailty is the accumulation of deficits conferring an increased risk of adverse outcomes. We set out to determine how severity of frailty, as measured using the CFS, affected delirium rates, and recognition in hospitalised older people in the United Kingdom. Methods: Adults over 65 years were included in an observational multi-centre audit across UK hospitals, two prospective rounds, and one retrospective note review. Clinical Frailty Scale (CFS), delirium status, and 30-day outcomes were recorded. Results: The overall prevalence of delirium was 16.3% (483). Patients with delirium were more frail than patients without delirium (median CFS 6 vs 4). The risk of delirium was greater with increasing frailty [OR 2.9 (1.8–4.6) in CFS 4 vs 1–3; OR 12.4 (6.2–24.5) in CFS 8 vs 1–3]. Higher CFS was associated with reduced recognition of delirium (OR of 0.7 (0.3–1.9) in CFS 4 compared to 0.2 (0.1–0.7) in CFS 8). These risks were both independent of age and dementia. Conclusion: We have demonstrated an incremental increase in risk of delirium with increasing frailty. This has important clinical implications, suggesting that frailty may provide a more nuanced measure of vulnerability to delirium and poor outcomes. However, the most frail patients are least likely to have their delirium diagnosed and there is a significant lack of research into the underlying pathophysiology of both of these common geriatric syndromes

Capacity enhancement of aqueous borohydride fuels for hydrogen storage in liquids

In this work we demonstrate enhanced hydrogen storage capacities through increased solubility of sodium borate product species in aqueous media achieved by adjusting the sodium (NaOH) to boron (B(OH)3) ratio, i.e., M/B, to obtain a distribution of polyborate anions. For a 1:1mol ratio of NaOH to B(OH)3, M/B=1, the ratio of the hydrolysis product formed from NaBH4 hydrolysis, the sole borate species formed and observed by 11B NMR is sodium metaborate, NaB(OH)4. When the ratio is 1:3 NaOH to B(OH)3, M/B=0.33, a mixture of borate anions is formed and observed as a broad peak in the 11B NMR spectrum. The complex polyborate mixture yields a metastable solution that is difficult to crystallize. Given the enhanced solubility of the polyborate mixture formed when M/B=0.33 it should follow that the hydrolysis of sodium octahydrotriborate, NaB3H8, can provide a greater storage capacity of hydrogen for fuel cell applications compared to sodium borohydride while maintaining a single phase. Accordingly, the hydrolysis of a 23wt.% NaB3H8 solution in water yields a solution having the same complex polyborate mixture as formed by mixing a 1:3M ratio of NaOH and B(OH)3 and releases \u3e8eq of H2. By optimizing the M/B ratio a complex mixture of soluble products, including B3O3(OH)5 2-, B4O5(OH)4 2-, B3O3(OH)4 -, B5O6(OH)4 - and B(OH)3, can be maintained as a single liquid phase throughout the hydrogen release process. Consequently, hydrolysis of NaB3H8 can provide a 40% increase in H2 storage density compared to the hydrolysis of NaBH4 given the decreased solubility of sodium metaborate

The Effectiveness of a Multidisciplinary Electronic Discharge Readiness Tool: Prospective, Single-Center, Pre-Post Study

BackgroundIn the face of hospital capacity strain, hospitals have developed multifaceted plans to try to improve patient flow. Many of these initiatives have focused on the timing of discharges and on lowering lengths of stay, and they have met with variable success. We deployed a novel tool in the electronic health record to enhance discharge communication. ObjectiveThe aim of this study is to evaluate the effectiveness of a discharge communication tool. MethodsThis was a prospective, single-center, pre-post study. Hospitalist physicians and advanced practice providers (APPs) used the Discharge Today Tool to update patient discharge readiness every morning and at any time the patient status changed throughout the day. Primary outcomes were tool use, time of day the clinician entered the discharge order, time of day the patient left the hospital, and hospital length of stay. We used linear mixed modeling and generalized linear mixed modeling, with team and discharging provider included in all the models to account for patients cared for by the same team and the same provider. ResultsDuring the pilot implementation period from March 5, 2019, to July 31, 2019, a total of 4707 patients were discharged (compared with 4558 patients discharged during the preimplementation period). A total of 352 clinical staff had used the tool, and 84.85% (3994/4707) of the patients during the pilot period had a discharge status assigned at least once. In a survey, most respondents reported that the tool was helpful (32/34, 94% of clinical staff) and either saved time or did not add additional time to their workflow (21/24, 88% of providers, and 34/34, 100% of clinical staff). Although improvements were not observed in either unadjusted or adjusted analyses, after including starting morning census per team as an effect modifier, there was a reduction in the time of day the discharge order was entered into the electronic health record by the discharging physician and in the time of day the patient left the hospital (decrease of 2.9 minutes per additional patient, P=.07, and 3 minutes per additional patient, P=.07, respectively). As an effect modifier, for teams that included an APP, there was a significant reduction in the time of day the patient left the hospital beyond the reduction seen for teams without an APP (decrease of 19.1 minutes per patient, P=.04). Finally, in the adjusted analysis, hospital length of stay decreased by an average of 3.7% (P=.06). ConclusionsThe Discharge Today tool allows for real time documentation and sharing of discharge status. Our results suggest an overall positive response by care team members and that the tool may be useful for improving discharge time and length of stay if a team is staffed with an APP or in higher-census situations