Optical scattering methods applicable to drops and bubbles

An overview of optical scattering properties of drops and bubbles is presented. The properties lead to unconventional methods for optically monitoring the size or shape of a scatterer and are applicable to acoustically levitated objects. Several of the methods are applicable to the detection and measurement of small amplitude oscillations. Relevant optical phenomena include: (1) rainbows; (2) diffraction catastrophes from spheroids; (3) critical angle scattering; (4) effects of coatings; (5) glory scattering; and (6) optical levitation

Glory in optical backscattering from air bubbles

Observations of light backscattered from air bubbles in a viscous liquid demonstrate an enhancement due to axial focusing. A physical-optics approximation for the cross-polarized scattering correctly describes the spacing of regular features observed. The non-cross polarized scattering is not adequately described by a single class of rays

Failures of the classical optical theorem under arbitrary-shaped beam incidence in electromagnetism, acoustics, and quantum mechanics: motivation and a review

The classical optical theorem states that for a wave propagating in a lossless medium and incident on a finite scatterer, the extinction cross section is proportional to the real part of the scattering amplitude in the forward direction. When developing a light scattering theory known as the generalized Lorenz–Mie theory, it has been a surprise to observe that in 1982, the optical theorem failed when the scatterer was illuminated by an arbitrary-shaped beam. The extremely simple reason for that failure has been understood only in 2014 and published in 2016. This represents a more than three-decade-long story, which is called a “wow” story for reasons that will be mentioned in this paper. The opportunity of this story which pertains to both the history and philosophy of sciences is considered to provide a review of the optical theorem under arbitrary-shaped beam incidence in electromagnetism, acoustics, and quantum mechanics

Nearest-neighbour Attraction Stabilizes Staggered Currents in the 2D Hubbard Model

Using a strong-coupling approach, we show that staggered current vorticity does not obtain in the repulsive 2D Hubbard model for large on-site Coulomb interactions, as in the case of the copper oxide superconductors. This trend also persists even when nearest-neighbour repulsions are present. However, staggered flux ordering emerges {\bf only} when attractive nearest-neighbour Coulomb interactions are included. Such ordering opens a gap along the $(\pi,0)-(0,\pi)$ direction and persists over a reasonable range of doping.Comment: 5 pages with 5 .eps files (Typos in text are corrected

Optical Glory of Small Freely Rising Gas Bubbles in Water: Observed and Computed Cross-Polarized Backscatter Patterns

Light scattered from spherical bubbles in water manifests an enhancement in the backward direction analogous to the well-known optical glory of a drop. Unlike the glory for water drops, in which the rays travel partially on the drop's surface, the glory for bubbles is due to rays that are refracted and multiply reflected within the scatterer and is an example of a transmitted wave glory. Photographs of glory scattering for freely rising air bubbles in water are displayed for bubbles having diameters of less than 300 ym. A physical-optics model for backscattering is developed for spherical bubbles. Computed glory patterns from both Mie-series calculations and the physicaloptics model agree with the observed patterns. The patterns of freely rising air bubbles having a diameter of S300 ,am are essentially those predicted for a spherical scatterer. The interference of different classes of glory rays is more clearly seen for bubbles in water than for the previously studied case of bubbles in oil

Older UK sheltered housing tenants’ perceptions of wellbeing and their usage of hospital services

The aim of this study was to examine sheltered housing tenants’ views of health and wellbeing, the strategies they adopted to support their wellbeing and their use of health and social care services through a Health Needs Assessment. Sheltered housing in the UK is a form of service-integrated housing for people, predominantly over 60. The study used a parallel, three-strand mixed method approach to encompass the tenants’ perceptions of health and wellbeing (n=96 participants), analysis of the service’s health and wellbeing database and analysis of emergency and elective hospital admissions (n= 978 tenant data sets for the period January to December 2012). Tenants’ perceptions of wellbeing were seen to reinforce much of the previous work on the subject with strategies required to sustain social, community, physical, economic, environmental, leisure, emotional and spiritual dimensions. Of the tenants’ self-reported chronic conditions, arthritis, heart conditions and breathing problems were identified as their most common health concerns. Hospital admission data indicated that 43% of the tenant population was admitted to hospital (886 admissions) with 53% emergency and 47% elective admissions. The potential cost of emergency as opposed to elective admissions was substantial. The mean length of stay for emergency admissions was 8.2 days (median 3.0 days). While elective hospital admission had a mean length of stay of 1.0 day (median 0.0 days). These results suggest the need for multi-professional health, social care and housing services interventions to facilitate sheltered housing tenants’ aspirations and support their strategies to live well and independently in their own homes. Equally there is a need to increase tenants’ awareness of health conditions and their management; the importance of services which offer facilitation, resources and support and the key role played by prevention and reablement

Approaches to integrated housing, health and social care services: case studies from North Tyneside Council and Northumbria Healthcare

The Care Act 2014 places a duty on local authorities to integrate services, including housing, where this could improve wellbeing by preventing, reducing and/or delaying care needs (LGA 2015). Despite calls for greater collaborative working between housing and health professionals, there are limited examples of live projects taking an integrated approach to service delivery. This case study report presents three case studies of innovative approaches to integrated working across housing, health and adult social care from North Tyneside Council and Northumbria Healthcare Foundation Trust. The case studies highlight the relevance of understanding access processes within different services, the role of workforce development in aligning referral and access pathways, targeted and more cost-effective health intervention delivery via housing services, and the potential for achieving health outcomes through housing improvement. Understanding of these issues informed the approach that was developed for the co-ordination of services and departments to work together across organization and sector boundaries

COMPare: Qualitative analysis of researchers' responses to critical correspondence on a cohort of 58 misreported trials.

BACKGROUND: Discrepancies between pre-specified and reported outcomes are an important and prevalent source of bias in clinical trials. COMPare (Centre for Evidence-Based Medicine Outcome Monitoring Project) monitored all trials in five leading journals for correct outcome reporting, submitted correction letters on all misreported trials in real time, and then monitored responses from editors and trialists. From the trialists' responses, we aimed to answer two related questions. First, what can trialists' responses to corrections on their own misreported trials tell us about trialists' knowledge of correct outcome reporting? Second, what can a cohort of responses to a standardised correction letter tell us about how researchers respond to systematic critical post-publication peer review? METHODS: All correspondence from trialists, published by journals in response to a correction letter from COMPare, was filed and indexed. We analysed the letters qualitatively and identified key themes in researchers' errors about correct outcome reporting, and approaches taken by researchers when their work was criticised. RESULTS: Trialists frequently expressed views that contradicted the CONSORT (Consolidated Standards of Reporting Trials) guidelines or made inaccurate statements about correct outcome reporting. Common themes were: stating that pre-specification after trial commencement is acceptable; incorrect statements about registries; incorrect statements around the handling of multiple time points; and failure to recognise the need to report changes to pre-specified outcomes in the trial report. We identified additional themes in the approaches taken by researchers when responding to critical correspondence, including the following: ad hominem criticism; arguing that trialists should be trusted, rather than follow guidelines for trial reporting; appealing to the existence of a novel category of outcomes whose results need not necessarily be reported; incorrect statements by researchers about their own paper; and statements undermining transparency infrastructure, such as trial registers. CONCLUSIONS: Researchers commonly make incorrect statements about correct trial reporting. There are recurring themes in researchers' responses when their work is criticised, some of which fall short of the scientific ideal. Research on methodological shortcomings is now common, typically in the form of retrospective cohort studies describing the overall prevalence of a problem. We argue that prospective cohort studies which additionally issue correction letters in real time on each individual flawed study-and then follow-up responses from trialists and journals-are more impactful, more informative for those consuming the studies critiqued, more informative on the causes of shortcomings in research, and a better use of research resources

The FNIP co-chaperones decelerate the Hsp90 chaperone cycle and enhance drug binding

The ability of Heat Shock Protein 90 (Hsp90) to hydrolyze ATP is essential for its chaperone function. The co-chaperone Aha1 stimulates Hsp90 ATPase activity, tailoring the chaperone function to specific "client" proteins. The intracellular signaling mechanisms directly regulating Aha1 association with Heat shock protein-90 (Hsp90) is an essential molecular chaperone in eukaryotes involved in maintaining the stability and activity of numerous signalling proteins, also known as clients. Hsp90 ATPase activity is essential for its chaperone function and it is regulated by co-chaperones. Here we show that the tumour suppressor FLCN is an Hsp90 client protein and its binding partners FNIP1/FNIP2 function as co-chaperones. FNIPs decelerate the chaperone cycle, facilitating FLCN interaction with Hsp90, consequently ensuring FLCN stability. FNIPs compete with the activating co-chaperone Aha1 for binding to Hsp90, thereby providing a reciprocal regulatory mechanism for chaperoning of client proteins. Lastly, downregulation of FNIPs desensitizes cancer cells to Hsp90 inhibitors, whereas FNIPs overexpression in renal tumours compared with adjacent normal tissues correlates with enhanced binding of Hsp90 to its inhibitors. Our findings suggest that FNIPs expression can potentially serve as a predictive indicator of tumour response to Hsp90 inhibitors