Universality in escape from a modulated potential well

We show that the rate of activated escape $W$ from a periodically modulated potential displays scaling behavior versus modulation amplitude $A$. For adiabatic modulation of an optically trapped Brownian particle, measurements yield $\ln W\propto (A_{\rm c} - A)^{\mu}$ with $\mu = 1.5$. The theory gives $\mu=3/2$ in the adiabatic limit and predicts a crossover to $\mu=2$ scaling as $A$ approaches the bifurcation point where the metastable state disappears.Comment: 4 pages, 3 figure

Reliability of functional outcome measures in adults with neurofibromatosis 1

Objectives: To determine intra-rater and inter-rater reliability of functional outcome measures in adults with neurofibromatosis 1 (NF1) and to ascertain how closely objective and subjective measures align. Methods: Forty-nine ambulant adults with NF1 aged 16 years and over were included in this observational study. Median age 31 years (range 16-66), 29 females, 20 males. Participants were video-recorded or photographed performing four functional outcome measures. Four raters from the Neurofibromatosis centre multi-disciplinary team independently scored the measures to determine inter-rater reliability. One rater scored the measures a second time on a separate occasion to determine intra-rater reliability. The measures evaluated were the functional reach, timed up and go, ten metre walk and a modified nine-hole peg tests. Participants also completed a disease specific quality of life questionnaire (INF1-QOL). Results: Inter-rater reliability and intra-rater reliability scores (intra-class coefficient, ICC) were similar for each outcome measure. Excellent rater agreement (ICC r ≥ 0.9) was found for the functional reach, timed up and go and the 10 metre walk tests. Rater agreement was good for the modified 9-hole peg test; ICC r= 0.75 for intra-rater reliability and 0.76 for inter-rater reliability. The timed up and go and the 10 metre walk tests correlated highly with perceived mobility challenges in the quality of life questionnaire (INF1-QOL). Conclusions: The functional reach, timed up and go and 10 metre walk tests are potentially useful outcome measures for monitoring NF1 treatment and will be assessed for validity and reliability in future multi-centre studies

Development and application of rice starch based edible coating to improve the postharvest storage potential and quality of plum fruit (<i>Prunus salicina</i>)

The study investigated the possibility of enhancing the shelf life of plum fruit coated with rice starch-ι-carrageenan (RS-ι-car) composite coating blended with sucrose fatty acid esters (FAEs). Film solution (starch 3%, carrageenan 1.5% and FAEs 2%) was prepared by mixing the ingredients and properties of stand-alone films (physical, mechanical, barrier and surface morphology) were studied before applying the coating on fruit surface. Fruit were stored at 20 °C for 3 weeks and analyzed for weight loss, ethylene production, respiration rate, color change, firmness, and titratable acidity (TA) and soluble solid content (SSC). Surface morphology of stand-alone film and fruit surface (after applying on the plum fruit) was studied using scanning electron microscopy (SEM). Phytochemical analysis was performed during the storage period and total phenolic content (TPC), total antioxidant capacity (TAC), flavonoid content (FC) and free radical scavenging activity were determined. The rice starch composite coating was shown to be effective in reducing both weight loss (WL) and respiration rate and inhibiting the endogenous ethylene production when compared to the uncoated control fruit stored at room temperature (p &lt; 0.05). TPC, TAC, FC and free radical scavenging activity was unaffected in the coated fruit throughout the storage period (p &lt; 0.05). The findings reported in this study indicate that the RS-ι-car-FAEs coating prolongs the shelf life and maintains the overall quality of plum fruit during storage and could potentially be commercialized as a new edible coating for the plum fruit industry

Suppression of prion protein in livestock by RNA interference

Given the difficulty of applying gene knockout technology to species other than mice, we decided to explore the utility of RNA interference (RNAi) in silencing the expression of genes in livestock. Short hairpin RNAs (shRNAs) were designed and screened for their ability to suppress the expression of caprine and bovine prion protein (PrP). Lentiviral vectors were used to deliver a transgene expressing GFP and an shRNA targeting PrP into goat fibroblasts. These cells were then used for nuclear transplantation to produce a cloned goat fetus, which was surgically recovered at 81 days of gestation and compared with an age-matched control derived by natural mating. All tissues examined in the cloned fetus expressed GFP, and PCR analysis confirmed the presence of the transgene encoding the PrP shRNA. Most relevant, Western blot analysis performed on brain tissues comparing the transgenic fetus with control demonstrated a significant (>90%) decrease in PrP expression levels. To confirm that similar methodologies could be applied to the bovine, recombinant virus was injected into the perivitelline space of bovine ova. After in vitro fertilization and culture, 76% of the blastocysts exhibited GFP expression, indicative that they expressed shRNAs targeting PrP. Our results provide strong evidence that the approach described here will be useful in producing transgenic livestock conferring potential disease resistance and provide an effective strategy for suppressing gene expression in a variety of large-animal models

UK Large-scale Wind Power Programme from 1970 to 1990: the Carmarthen Bay experiments and the Musgrove Vertical-Axis Turbines

This article describes the development of the Musgrove Vertical Axis Wind Turbine (VAWT) concept, the UK ‘Carmarthen Bay’ wind turbine test programme, and UK government’s wind power programme to 1990. One of the most significant developments in the story of British wind power occurred during the 1970s, 1980s, and 1990s, with the development of the Musgrove vertical axis wind turbine and its inclusion within the UK Government’s wind turbine test programme. Evolving from a supervisor’s idea for an undergraduate project at Reading University, the Musgrove VAWT was once seen as an able competitor to the horizontal axis wind systems that were also being encouraged at the time by both the UK government and the Central Electricity Generating Board, the then nationalised electricity utility for England and Wales. During the 1980s and 1990s the most developed Musgrove VAWT system, along with three other commercial turbine designs was tested at Carmarthen Bay, South Wales as part of a national wind power test programme. From these developmental tests, operational data was collected and lessons learnt, which were incorporated into subsequent wind power operations.http://dx.doi.org/10.1260/03095240677860621

Scaling and crossovers in activated escape near a bifurcation point

Near a bifurcation point a system experiences critical slowing down. This leads to scaling behavior of fluctuations. We find that a periodically driven system may display three scaling regimes and scaling crossovers near a saddle-node bifurcation where a metastable state disappears. The rate of activated escape $W$ scales with the driving field amplitude $A$ as $\ln W \propto (A_c-A)^{\xi}$, where $A_c$ is the bifurcational value of $A$. With increasing field frequency the critical exponent $\xi$ changes from $\xi = 3/2$ for stationary systems to a dynamical value $\xi=2$ and then again to $\xi=3/2$. The analytical results are in agreement with the results of asymptotic calculations in the scaling region. Numerical calculations and simulations for a model system support the theory.Comment: 18 page

Community action projects: community-engaged quality improvement for medical students.

BACKGROUND: Healthcare Quality Improvement (QI) is an essential skill for medical students to acquire, although there is insufficient empirical research which suggests the best educational methods to do this. This study explored the experiences of medical students participating in two versions of a Community Action Project (CAP) which gave medical students the opportunity to learn QI skills in a community setting. The first version (GPCAP) was pre-pandemic where students identified and delivered QI projects on placement in general practice to improve local population health. The second version (Digi-CAP) ran remotely where students worked on QI projects identified by local voluntary sector organisations focused on local community priorities during COVID-19. METHODS: Semi-structured interviews were conducted with volunteers from the two cohorts of students who had taken part in quality improvement initiatives. Transcriptions were independently coded by two researchers and analysed through thematic analysis. RESULTS: Sixteen students were interviewed. Whilst students had mixed experiences of completing their CAP, engagement and successful learning was associated with the following themes from the two versions of QI CAP projects: finding a sense of purpose and meaning in QI projects; preparedness for responsibility and service-driven learning; the importance of having supportive partnerships throughout the project duration and making a sustainable difference. CONCLUSIONS AND IMPLICATIONS: The study provides valuable insights into the design and implementation of these community-based QI projects, which enabled students to learn new and often hard to teach skills, whilst working on projects which have a sustainable impact on local community outcomes