Optimal shield mass distribution for space radiation protection

Computational methods have been developed and successfully used for determining the optimum distribution of space radiation shielding on geometrically complex space vehicles. These methods have been incorporated in computer program SWORD for dose evaluation in complex geometry, and iteratively calculating the optimum distribution for (minimum) shield mass satisfying multiple acute and protected dose constraints associated with each of several body organs

Analysis of the geomagnetic activity of the D(st) index and self-affine fractals using wavelet transforms

The geomagnetic activity of the D(st) index is analyzed using wavelet transforms and it is shown that the D(st) index possesses properties associated with self-affine fractals. For example, the power spectral density obeys a power-law dependence on frequency, and therefore the D(st) index can be viewed as a self-affine fractal dynamic process. In fact, the behaviour of the D(st) index, with a Hurst exponent H≈0.5 (power-law exponent β≈2) at high frequency, is similar to that of Brownian motion. Therefore, the dynamical invariants of the D(st) index may be described by a potential Brownian motion model. Characterization of the geomagnetic activity has been studied by analysing the geomagnetic field using a wavelet covariance technique. The wavelet covariance exponent provides a direct effective measure of the strength of persistence of the D(st) index. One of the advantages of wavelet analysis is that many inherent problems encountered in Fourier transform methods, such as windowing and detrending, are not necessary

Impact of radiation dose on nuclear shuttle configuration

The impact of nuclear radiation (from the NERVA propulsion system) on the selection of a reference configuration for each of two classes of the reusable nuclear shuttle is considered. One class was characterized by a single propellant tank, the shape of whose bottom was found to have a pronounced effect on crew radiation levels and associated shield weight requirements. A trade study of shield weight versus structural weight indicated that the minimum-weight configuration for this class had a tank bottom in the shape of a frustum of a 10 deg-half-angle cone. A hybrid version of this configuration was found to affect crew radiation levels in substantially the same manner. The other class of RNS consisted of a propulsion module and eight propellant modules. Radiation analyses of various module arrangements led to a design configuration with no external shield requirements

Methods of space radiation dose analysis with applications to manned space systems

The full potential of state-of-the-art space radiation dose analysis for manned missions has not been exploited. Point doses have been overemphasized, and the critical dose to the bone marrow has been only crudely approximated, despite the existence of detailed man models and computer codes for dose integration in complex geometries. The method presented makes it practical to account for the geometrical detail of the astronaut as well as the vehicle. Discussed are the major assumptions involved and the concept of applying the results of detailed proton dose analysis to the real-time interpretation of on-board dosimetric measurements

Multiscale time series modelling with an application to the relativistic electron intensity at the geosynchronous orbit

In this paper, a Bayesian system identification approach to multiscale time series modelling is proposed, where multiscale means that the output of the system is observed at one(coarse) resolution while the input of the system is observed at another (One) resolution. The proposed method identifies linear models at different levels of resolution where the link between the two resolutions is realised via non-overlapping averaging process. This averaged time series at the coarse level of resolution is assumed to be a set of observations from an implied process so that the implied process and the output of the system result in an errors-in-variables ARMAX model at the coarse level of resolution. By using a Bayesian inference and Markov Chain Monte Carlo (MCMC) method, such a modelling framework results in different dynamical models at different levels of resolution at the same time. The new method is also shown to have the ability to combine information across different levels of resolution. An application to the analysis of the relativistic electron intensity at the geosynchronous orbit is used to illustrate the new method

Evaluation of the Outpatients consultation in East Kent

CHSS undertook to support Kent and Medway Commissioning Support (KMCS: acting on behalf of East Kent Hospitals University NHS Foundation Trust and NHS Canterbury and Coastal Clinical Commissioning Group) in undertaking an independent analysis of a consultation on Outpatient services in East Kent. The aim of the consultation was to gain opinions from the public of a proposed Outpatient Clinical Strategy that intends to improve local access to, and facilities for, Outpatient services, and to offer a wider range of services on each site. CHSS advised on the survey, evaluated the consultation process, ran focus groups and carried out quantitative and qualitative analysis of the responses gathered during the consultation period (9th December 2013 to 17th March, 2014 - originally 9th March but period was extended). Ethical approval was not required for a consultation process, but ethical principles have been adhered to regarding data confidentiality and informed consent for the focus groups

Agriculture and poverty in the Kentucky mountains: Beech Creek and Clay County, 1850-1910

The poverty of Appalachia is not the product of modernization. Nor is it a unique phenomenon. An examination of the history of farming in Beech Creek, Kentucky, reveals that this community, which was prosperous in 1860, owed its fall into poverty to a number of factors that had impoverished other regions: the high rate of population growth among the families living in the area, the division and re-division of the limited land to accommodate the new generations of families, the need to use woodland for agriculture before reforestation succeeded in restoring the old soil to its original productivity, and slow economic growth resulting from the emphasis on subsistence rather than commercial agriculture. The same pattern had occurred in New England in the eighteenth century. What was unique in Appalachia was that subsistence farming lasted so long, owing to growing isolation from the rest of the country as the area was bypassed in the construction of modern means of transportation.

Service Development Programme: Maximising Life Opportunities for Teenagers. Teenagers' Views and Experiences of Sex and Relationships Education, Sexual Health Services and Family Support Services in Kent - Survey findings for Year 2

This brief report provides findings from data collected in year 2 of a survey of teenagers' views and experiences of sex and relationships education and sexual health services in Kent. The data in year 2 was collected in Autumn 2005, a year after the data collected in year 1. The purpose of this report is to highlight the results in year 2 which differ from the year 1 survey data. It is to be used in conjunction with the report in year 1 entitled "Service Development Programme: Maximising Life Opportunies for Teenagers: Teenagers' Views and Experiences of Sex and Relationships Educatioon, Sexual Health Services and Family Suupport Services in Kent: Survey Findings July 2005". The final report on the survey will consist of findings from further analysis of the data from year 1 and year 2 merged together, available at the end of 2006

Biophysical modelling of a drosophila photoreceptor

It remains unclear how visual information is co-processed by different layers of neurons in the retina. In particular, relatively little is known how retina translates vast environmental light changes into neural responses of limited range. We began examining this question in a bottom-up way in a relatively simple °y eye. To gain understanding of how complex bio-molecular interactions govern the conversion of light input into voltage output (phototransduction), we are building a biophysical model of the Drosophila R1-R6 photoreceptor. Our model, which relates molecular dynamics of the underlying biochemical reactions to external light input, attempts to capture the molecular dynamics of phototransduction gain control in a quantitative way

Multicultural Face Recognition Memory And Own-Race-Bias Among Adults With Acquired Brain Injury

Own-race bias (ORB) is a well-documented phenomenon that may influence face memory, such that face memory is improved when the observed target matches the observer’s racial background. However, the clinical measures widely used in neuropsychological evaluations lack racial diversity that may disenfranchise and disadvantage minority patients. Further, these existing measures have been criticized for having inconsistent visual contrast and facial content, as well as too much variability of non-facial information which may confound its acceptability as a measure of face memory specifically. To address these limitations, standardized, multicultural images with validated facial expressions (Beaupré et al., 2000) were used to create the Multicultural Facial Recognition Test (MCFR) to evaluate face recognition memory and ORB in a clinically relevant sample of persons with acquired brain injuries. Method: One-hundred fifteen adults (63 Black, 52 White) with history of acquired brain injury participated. The participants ranged in age from 18 to 79 and were on average 12 years post injury. Participants completed a battery of cognitive tests, including the MCFR, the criterion Warrington Recognition Memory Test (RMT-F), and a post-test survey to provide consumer feedback on the MCFR. Results: Internal consistency reliability of the MCFR was low, but the MCFR showed evidence of convergent validity as expected by theory. The MCFR correlated with the RMT-F and a measure of visual memory. However, the patterns of correlations among the MCFR and the cognitive measures differed significantly for Black and White participants. Additionally, evidence for ORB was present; however, this finding was only significant among Black participants. Although both racial groups performed best on the RMT-F, both groups also endorsed preferring the MCFR over the RMT-F. Conclusions: The findings support evidence of ORB, but also suggest that ORB may be differently experienced by ABI patients of different racial groups. These findings highlight the need to include multicultural stimuli in the development of valid tests of face memory, as well as, the necessity to include multicultural participants in clinical research, as findings from the dominant culture may not generalized to minority populations. Further evaluation of the psychometric properties of the MCFR should be pursued