Structure in the 3D Galaxy Distribution: I. Methods and Example Results

Three methods for detecting and characterizing structure in point data, such as that generated by redshift surveys, are described: classification using self-organizing maps, segmentation using Bayesian blocks, and density estimation using adaptive kernels. The first two methods are new, and allow detection and characterization of structures of arbitrary shape and at a wide range of spatial scales. These methods should elucidate not only clusters, but also the more distributed, wide-ranging filaments and sheets, and further allow the possibility of detecting and characterizing an even broader class of shapes. The methods are demonstrated and compared in application to three data sets: a carefully selected volume-limited sample from the Sloan Digital Sky Survey redshift data, a similarly selected sample from the Millennium Simulation, and a set of points independently drawn from a uniform probability distribution -- a so-called Poisson distribution. We demonstrate a few of the many ways in which these methods elucidate large scale structure in the distribution of galaxies in the nearby Universe.Comment: Re-posted after referee corrections along with partially re-written introduction. 80 pages, 31 figures, ApJ in Press. For full sized figures please download from: http://astrophysics.arc.nasa.gov/~mway/lss1.pd

The quest for the solar g modes

Solar gravity modes (or g modes) -- oscillations of the solar interior for which buoyancy acts as the restoring force -- have the potential to provide unprecedented inference on the structure and dynamics of the solar core, inference that is not possible with the well observed acoustic modes (or p modes). The high amplitude of the g-mode eigenfunctions in the core and the evanesence of the modes in the convection zone make the modes particularly sensitive to the physical and dynamical conditions in the core. Owing to the existence of the convection zone, the g modes have very low amplitudes at photospheric levels, which makes the modes extremely hard to detect. In this paper, we review the current state of play regarding attempts to detect g modes. We review the theory of g modes, including theoretical estimation of the g-mode frequencies, amplitudes and damping rates. Then we go on to discuss the techniques that have been used to try to detect g modes. We review results in the literature, and finish by looking to the future, and the potential advances that can be made -- from both data and data-analysis perspectives -- to give unambiguous detections of individual g modes. The review ends by concluding that, at the time of writing, there is indeed a consensus amongst the authors that there is currently no undisputed detection of solar g modes.Comment: 71 pages, 18 figures, accepted by Astronomy and Astrophysics Revie

Assessment of treatment-induced female sexual morbidity in oncology: is this a part of routine medical follow-up after radical pelvic radiotherapy?

Background:Oncology follow-up has traditionally prioritised disease surveillance and the assessment and management of symptoms associated with cancer and its treatment. Over the past decade, the focus on late effects of treatment has increased, particularly those that have an adverse effect on long-term function and quality of life. The aim of this research was to explore factors that influence the identification of treatment-induced female sexual difficulties in routine oncology follow-up after radical pelvic radiotherapy.Methods:A structured observation schedule was used to systematically record topics discussed in 69 radiotherapy follow-up consultations observed over a 5-month period.Results:Analysis suggests that physical toxicity assessment focused on bowel (81%) and bladder (70%) symptoms. Vaginal toxicity was discussed less frequently (42%) and sexual issues were explored in only 25% of consultations. Formal recording of radiation toxicity through assessment questionnaires was limited to patients participating in clinical trials. Surveillance activity and the management of active physical symptoms predominated and psychosocial issues were addressed in only 42% of consultations.Interpretation:Female sexual morbidity after pelvic radiotherapy remains a neglected aspect of routine follow-up and cancer survivorship. Developments in both individual practice and service provision are necessary if the identification and management of treatment-induced female sexual difficulties is to be improved