Scattering from a large cylinder with an eccentrically embedded core: An orders-of-scattering approximation,”

a b s t r a c t We develop an orders-of-scattering approximation, termed the "screened cylindrical void/ core" (SCV) approximation, for a composite cylinder. The composite cylinder consists of a large host cylinder that contains a small, eccentrically embedded, core cylinder. The SCV approximation is developed via separation of variables in conjunction with addition theorems for cylindrical functions. We show that the SCV approximation is in good agreement with the numerically exact solution. A simple physical interpretation of the SCV approximation is also presented

Aggressive behavioural interactions between swans (Cygnus spp.) and other waterbirds during winter: A webcam-based study

This is the final version. Available on open access from BMC via the DOI in this recordAvailability of data and materials: The datasets generated and analysed during the current study are available from the corresponding author upon reasonable request.Background: Our understanding of any impacts of swans on other waterbirds (including other swans), and potential effects on waterbird community structure, remain limited by a paucity of fundamental behavioural and ecological data, including which species swans interact aggressively with and how frequently such interactions occur. Methods: Behavioural observations of aggression by swans and other waterbirds in winters 2018/2019 and 2019/2020, were carried out via live-streaming webcams at two wintering sites in the UK. All occurrence sampling was used to identify all aggressive interactions between conspecific or heterospecifics individuals, whilst focal observations were used to record the total time spent by swans on aggressive interactions with other swans. Binomial tests were then used to assess whether the proportion of intraspecific aggressive interactions of each species differed from 0.5 (which would indicate equal numbers of intraspecific and interspecific interactions). Zero-inflated generalized linear mixed effects models (ZIGLMMs) were used to assess between-individual variation in the total time spent by swans on aggressive interactions with other swans. Results: All three swan species were most frequently aggressive towards, and received most aggression from, their conspecifics. Our 10-min focal observations showed that Whooper (Cygnus cygnus) and Bewick's Swans (C. columbianus bewickii) spent 13.8 ± 4.7 s (means ± 95% CI) and 1.4 ± 0.3 s, respectively, on aggression with other swans. These durations were equivalent to 2.3% and 0.2% of the Whooper and Bewick's Swan time-activity budgets, respectively. Model selection indicated that the time spent in aggressive interactions with other swans was best-explained by the number of other swans present for Whooper Swans, and an interactive effect of time of day and winter of observation for Bewick's Swans. However, the relationship between swan numbers and Whooper Swan aggression times was not strong (R 2 = 19.3%). Conclusions: Whilst swans do exhibit some aggression towards smaller waterbirds, the majority of aggression by swans is directed towards other swans. Aggression focused on conspecifics likely reflects greater overlap in resource use, and hence higher potential for competition, between individuals of the same species. Our study provides an example of how questions relating to avian behaviour can be addressed using methods of remote data collection such as live-streaming webcams.Wildfowl & Wetlands TrustUniversity of Exete

Stimulated Brillouin scattering during electron gyro-harmonic heating at EISCAT

Observations of secondary radiation, stimulated electromagnetic emission (SEE), produced during ionospheric modification experiments using ground-based, highpower, high-frequency (HF) radio waves are considered. The High Frequency Active Auroral Research Program (HAARP) facility is capable of generating narrowband SEE in the form of stimulated Brillouin scatter (SBS) and stimulated ion Bernstein scatter (SIBS) in the SEE spectrum. Such narrowband SEE spectral lines have not been reported using the European Incoherent Scatter (EISCAT) heater facility before. This work reports the first EISCAT results of narrowband SEE spectra and compares them to SEE previously observed at HAARP during electron gyro-harmonic heating. An analysis of experimental SEE data shows observations of emission lines within 100 Hz of the pump frequency, interpreted as SBS, during the 2012 July EISCAT campaign. Experimental results indicate that SBS strengthens as the pump frequency approaches the third electron gyro-harmonic. Also, for different heater antenna beam angles, the CUTLASS radar backscatter induced by HF radio pumping is suppressed near electron gyro-harmonics, whereas electron temperature enhancement weakens as measured by EISCAT/UHF radar. The main features of these new narrowband EISCAT observations are generally consistent with previous SBS measurements at HAARP

Engaging Emergency Department Patients in the Creation of a Shared Decision-­Making Tool Regarding CT Scanning in Kidney Stones: Challenges to Traditional Stakeholder Engagement

Background: Every year approximately 2 million patients are seen in US EDs for suspected renal colic, and the majority receive CT scans. The objective of our study was to develop a stakeholder-informed conversation aid to help clinicians use SDM regarding CT scanning in patients with suspected renal colic. Methods: Using a published decision aid development framework, and under the direction of a multi-disciplinary Steering Committee, we engaged a diverse set of stakeholders via qualitative methods. EM clinicians, urologists, radiologists, researchers, and emergency department patients participated in focus groups and semi-structured interviews. All groups were recorded, transcribed, and analyzed in an iterative process by a four-person coding team. Emergent themes were identified and used to develop a decision aid which was iteratively refined. Results: A total of 8 interviews and 7 focus groups were conducted with 36 stakeholders (including local ED patients) The following three themes emerged: 1. Patient participants reported a desire to be involved in this decision and wanted more information regarding risks and benefits of CT scans. 2. Clinicians were comfortable diagnosing kidney stones without a CT scan, however, some felt that clinical uncertainty was a barrier to SDM. 3. All stakeholders identified strategies to facilitate this conversation such as check-lists and visual aids. Conclusion: Using stakeholder input, we developed a communication tool to facilitate an SDM conversation around the use of CT in suspected renal colic. Further testing will assess whether this tool can safely improve patient engagement and decrease low yield CT usage

Use of specific Green's functions for solving direct problems involving a heterogeneous rigid frame porous medium slab solicited by acoustic waves

A domain integral method employing a specific Green's function (i.e., incorporating some features of the global problem of wave propagation in an inhomogeneous medium) is developed for solving direct and inverse scattering problems relative to slab-like macroscopically inhomogeneous porous obstacles. It is shown how to numerically solve such problems, involving both spatially-varying density and compressibility, by means of an iterative scheme initialized with a Born approximation. A numerical solution is obtained for a canonical problem involving a two-layer slab.Comment: submitted to Math.Meth.Appl.Sc

Improving the thermal stability of Rubisco activase

The thermal sensitivity of the key photosynthetic enzyme Rubisco activase limits wheat photosynthesis at moderately high temperatures. Introduction of a more thermal tolerant form of Rubisco activase, such as that from cotton, into wheat is predicted to broaden the temperature range of optimal Rubisco activation and photosynthetic CO2 assimilation. Transgenic lines have been produced to express the cotton Rubisco activase in wheat and current efforts are characterizing the most promising lines for further studies of photosynthetic performance at moderately high temperatures. Joanna Scales, a BBSRC PhD student jointly supervised by Martin Parry, Christine Raines, and Mike Salvucci, generated the transformation constructs and will undertake the molecular and biochemical analysis of the transformant lines. It is predicted that the cotton Rubisco activase will confer superior thermal tolerance to wheat photosynthesis

Improving the thermal stability of Rubisco activase

The major objective is to produce wheat germplasm with improved tolerance to heat stress through the modification of the key photosynthetic enzyme Rubisco activase. Current funds have allowed transformation of “best bet” candidate gene constructs into wheat as part of SP1.5. Joanna Scales, a BBSRC PhD student jointly supervised by Martin Parry, Christine Raines, and Mike Salvucci, generated the transformation constructs and will undertake the molecular and biochemical analysis of transgenic lines

Positive youth development in swimming: clarification and consensus of key psychosocial assets

The purpose of this study was to gain a more cohesive understanding of the assets considered necessary to develop in young swimmers to ensure both individual and sport specific development. This two stage study involved (a) a content analysis of key papers to develop a list of both psychosocial skills for performance enhancement and assets associated with positive youth development, and (b) in-depth interviews involving ten expert swim coaches, practitioners and youth sport scholars. Five higher order categories containing seventeen individual assets emerged. These results are discussed in relation to both existing models of positive youth development and implications for coaches, practitioners and parents when considering the psychosocial development of young British swimmers