Handling uncertainties in background shapes: the discrete profiling method

A common problem in data analysis is that the functional form, as well as the parameter values, of the underlying model which should describe a dataset is not known a priori. In these cases some extra uncertainty must be assigned to the extracted parameters of interest due to lack of exact knowledge of the functional form of the model. A method for assigning an appropriate error is presented. The method is based on considering the choice of functional form as a discrete nuisance parameter which is profiled in an analogous way to continuous nuisance parameters. The bias and coverage of this method are shown to be good when applied to a realistic example.Comment: Accepted by J.Ins

Examining the relationship between pubertal stage, adolescent health behaviours and stress

Background. This paper examines the associations between puberty and three important health behavlours (smoking, food intake and exercise) and explores whether these associations are mediated by puberty's relationship to stress and psychological difficulties.Method. Data were taken from the first year of the ongoing, 5-year, Health and Behaviours in Teenagers Study (HABITS). This is a school-based study set in 36 schools in London. In the first year of the study, 4320 students (2578 boys, 1742 girls) in their first year of secondary education took part.Results. Among girls, being more pubertally advanced was associated with a greater likelihood of having tried smoking. Among boys, being more pubertally advanced was associated with a greater likelihood of having tried smoking, a higher intake of high-fat food and higher levels of exercise. More pubertally advanced girls experienced more stress but not more psychological difficulties. There were no associations between puberty and either stress or psychological difficulties in boys. Stress and psychological difficulties were associated with health behaviours in girls and boys, but neither of these factors mediated the relationship between pubertal stage and health behaviours found in girls.Conclusions. These results suggest that the onset of puberty has a marked effect on the development of health behaviours. Puberty was related to an acceleration of the development of unhealthy behaviours, except for exercise behaviour in boys, where advanced puberty was associated with more exercise. These changes were unrelated to adolescent issues of stress and a causal explanation for these associations must be sought elsewhere

Phospholipid derived mediators and glomerulonephritis

The contributions made by the various eicosanoids, PAF, the HETES and the lipoxins to the pathophysiology of glomerulonephritis is reviewed. A case can be made for clinical trials of PAF, leukotriene and thromboxane antagonists. Combined thromboxane synthetase and thromboxane receptor antagonism would seem to be the more efficacious approach for the various disease entities

Phantom Ocean, Real Impact: Natural Surf Sound Experiments Alter Foraging Activity and Habitat Use Across Taxa

A growing body of research focuses on how background sounds shape and alter critical elements of animals’ lives, such as foraging behavior, habitat use, and ecological interactions (Bradbury & Vehrencamp, 2011; Barber et al., 2010; Kight & Swaddle, 2011; Shannon et al., 2016). Much of this research has centered on the effects of anthropogenic noise (Dominoni et al., 2020; Francis & Barber, 2013; Ortega, 2012; Swaddle et al., 2015), but recent studies have also revealed that natural sound sources can influence animal behavior (Davidson et al., 2017; Le et al., 2019). Natural sounds, such as crashing surf, can create conditions where signaling and listening are difficult, but how this influences different species’ ecological interactions are unknown. To study the effects of crashing surf sound we experimentally introduced landscape-level acoustic playbacks where surf sound was not naturally present to create a “phantom ocean”. Phantom ocean treatment sites were employed alongside higher frequency “shifted” treatment sites to test for frequency-dependent effects, “real ocean” sites where surf sound was endemic, and ambient control sites. The phantom and shifted treatments were played continuously during the spring and summer of 2017-2019. Within this acoustic experimental landscape we conducted multiple studies to test the effects of crashing surf sound on animal behavior, habitat use, and ecological interactions. Through an artificial caterpillar predation experiment modeled after Roslin et al. (2017), we found that when exposed to natural sound treatments the foraging activity of rodents and arthropods increased, while that of birds declined. A potential explanation for this pattern includes taxon-specific responses reflecting different perceived risk-reward trade-offs in natural sound conditions. To follow this up we performed occupancy modeling on data collected by camera traps set within our system. We observed different responses among groups of species with different functional roles in the community for both detection (p) and occupancy (Ψ) probabilities. Our combined results indicate different species and functional groups have unique foraging behavior and patch use responses to natural sounds, likely based on their ecological interactions. Specifically, Cricetid rodents are likely more active in areas exposed to natural sounds, possibly due to lower perceived predation risk because mesocarnivores are less active. Insectivorous birds are also likely less active under natural sounds conditions, although the frequency of the sound, and the body size and diet of the bird appear influential. Together these findings suggest that natural sounds shape not only individual behavioral adjustments, but also multi-trophic, community level interactions. Our results show that natural sounds are an important driver of ecological interactions, but much remains to be uncovered. The mechanisms by which natural sounds influence individuals, populations, and many other aspects of ecology remain unexplored and provide fertile ground for future inquiry

Adjusting the frequency of mammography screening on the basis of genetic risk: Attitudes among women in the UK.

Purpose To explore public attitudes towards modifying frequency of mammography screening based on genetic risk. Methods Home-based interviews were carried out with a population-based sample of 942 women aged 18–74 years in the UK. Demographic characteristics and perceived breast cancer (BC) risk were examined as predictors of support for risk-stratified BC screening and of the acceptability of raised or lowered screening frequency based on genetic risk, using multivariate logistic regression. Results Over two-thirds of respondents (65.8%) supported the idea of varying screening frequency on the basis of genetic risk. The majority (85.4%) were willing to have more frequent breast screening if they were found to be at higher risk, but fewer (58.8%) were willing to have less frequent screening if at lower risk (t (956) = 15.6, p < 0.001). Ethnic minority status was associated with less acceptability of more frequent screening (OR = 0.40, 95% CI = 0.21–0.74), but there were no other significant demographic correlates. Higher perceived risk of BC was associated with greater acceptability of more frequent screening (OR = 1.71, 95%CI = 1.27–2.30). Conclusion Women were positive about adjusting the frequency of mammography screening in line with personal genetic risk, but it will be important to develop effective communication materials to minimise resistance to reducing screening frequency for those at lower genetic risk

Resistive jet simulations extending radially self-similar magnetohydrodynamic models

Numerical simulations with self-similar initial and boundary conditions provide a link between theoretical and numerical investigations of jet dynamics. We perform axisymmetric resistive magnetohydrodynamic (MHD) simulations for a generalised solution of the Blandford & Payne type, and compare them with the corresponding analytical and numerical ideal-MHD solutions. We disentangle the effects of the numerical and physical diffusivity. The latter could occur in outflows above an accretion disk, being transferred from the underlying disk into the disk corona by MHD turbulence (anomalous turbulent diffusivity), or as a result of ambipolar diffusion in partially ionized flows. We conclude that while the classical magnetic Reynolds number $R_{\rm m}$ measures the importance of resistive effects in the induction equation, a new introduced number, \rbeta=(\beta/2)R_{\rm m} with $\beta$ the plasma beta, measures the importance of the resistive effects in the energy equation. Thus, in magnetised jets with $\beta<2$, when \rbeta \la 1 resistive effects are non-negligible and affect mostly the energy equation. The presented simulations indeed show that for a range of magnetic diffusivities corresponding to \rbeta \ga 1 the flow remains close to the ideal-MHD self-similar solution.Comment: Accepted for publication in MNRA

Multi-Wavelength Study of Sgr A*: The Short Time Scale Variability

To understand the correlation and the radiation mechanism of flare emission in different wavelength bands, we have coordinated a number of telescopes to observe SgrA* simultaneously. We focus only on one aspect of the preliminary results of our multi-wavelength observing campaigns, namely, the short time scale variability of emission from SgrA* in near-IR, X-ray and radio wavelengths. The structure function analysis indicate most of the power spectral density is detected on hourly time scales in all wavelength bands. We also report minute time scale variability at 7 and 13mm placing a strong constraint on the nature of the variable emission. The hourly time scale variability can be explained in the context of a model in which the peak frequency of emission shifts toward lower frequencies as a self-absorbed synchrotron source expands adiabatically near the acceleration site. The short time scale variability, on the other hand, places a strong constraint on the size of the emitting region. Assuming that rapid minute time scale fluctuations of the emission is optically thick in radio wavelength, light travel arguments requires relativistic particle energy, thus suggesting the presence of outflow from SgrA*.Comment: 9 pages, 4 figures, The Galactic Center: A Window on the Nuclear Environment of Disk Galaxies ASP Conference Series, 2010 eds: M. Morris, D. Q. Wang and F. Yua

Human papillomavirus (HPV) information needs: a theoretical framework

Background With the introduction of human papillomavirus (HPV) testing and vaccination in the UK, health professionals will start to receive questions about the virus from their patients. This study aimed to identify the key questions about HPV that British women will ask when considering having an HPV test or vaccination.Methods Face-to-face interviews were carried out with 21 women to discover what they wanted to know about HPV. A thematic framework approach was used to analyse the data and identify key themes in women's HPV knowledge requirements.Results Women's questions about HPV fell into six areas: identity (e.g. What are the symptoms?), cause (e.g. How do you get HPV?), timeline (e.g. How long does it last?), consequences (e.g. Does it always cause cervical cancer?) and control-cure (e.g. Can you prevent infection?). In addition, they asked procedural questions about testing and vaccination (e.g. Where do I get an HPV test?). These mapped well onto the dimensions identified in Leventhal's description of Jay models of illness, called the 'Common Sense Model' (CSM).Discussion and conclusions These results indicated that the majority of the questions women asked about HPV fitted well into the CSM, which therefore provides a structure for women's information needs. The findings could help health professionals understand what questions they may be expected to answer. Framing educational materials using the CSM themes may also help health educators achieve a good fit with what the public want to know