How Hot Is Radiation?

A self-consistent approach to nonequilibrium radiation temperature is introduced using the distribution of the energy over states. We begin rigorously with ensembles of Hilbert spaces and end with practical examples based mainly on the far from equilibrium radiation of lasers. We show that very high, but not infinite, laser radiation temperatures depend on intensity and frequency. Heuristic "temperatures" derived from a misapplication of equilibrium arguments are shown to be incorrect. More general conditions for the validity of nonequilibrium temperatures are also established.Comment: 26 pages, revised, LaTeX, 3 encapsulated PostScript figure

GA tuning of pitch controller for small scale MAVs

The paper presents the application of intelligent tuning methods for the control of a prototype MAV in order to address problems associated with bandwidth limited actuators and gust alleviation. Specifically, as a proof of concept, the investigation is focused on the pitch control of a MAV. The work is supported by experimental results from wind tunnel testing that shows the merits of the use of Genetic Algorithm (GA) tuning techniques compared to classical, empirical tuning methodologies. To provide a measure of relative merit, the controller responses are evaluated using the ITAE performance index. In this way, the proposed method is shown to induce far superior dynamic performance compared to traditional approaches

Birthweight, HIV exposure and infant feeding as predictors of malnutrition in Botswanan infants

Background: A better understanding of the nutritional status of infants who are HIV-Exposed-Uninfected (HEU) and HIV-Unexposed-Uninfected (HUU) during their first 1000 days is key to improving population health, particularly in sub-Saharan Africa. Methods: A cross-sectional study compared the nutritional status, feeding practices and determinants of nutritional status of HEU and HUU infants residing in representative selected districts in Botswana during their first 1000 days of life. Four hundred and thirteen infants (37.3% HIV-exposed), aged 6–24 months, attending routine child health clinics, were recruited. Anthropometric, 24-h dietary intake and socio-demographic data was collected. Anthropometric Z-scores were calculated using 2006 World Health Organization growth standards. Modelling of the determinants of malnutrition was undertaken using logistic regression. Results: Overall, the prevalences of stunting, wasting and being underweight were 10.4%, 11.9% and 10.2%, respectively. HEU infants were more likely to be underweight (15.6% versus 6.9%), (P &lt; 0.01) and stunted (15.6% versus 7.3%), (P &lt; 0.05) but not wasted (P = 0.14) than HUU infants. HEU infants tended to be formula fed (82.5%), whereas HUU infants tended to breastfeed (94%) for the first 6 months (P &lt; 0.001). Significant predictors of nutritional status were HIV exposure, birthweight, birth length, APGAR (appearance, pulse, grimace, activity and respiration) score and mother/caregiver's education with little influence of socio-economic status. Conclusions: HEU infants aged 6–24 months had worse nutritional status compared to HUU infants. Low birthweight was the main predictor of undernutrition in this population. Optimisation of infant nutritional status should focus on improving birthweight. In addition, specific interventions should target HEU infants aiming to eliminate growth disparity between HEU and HUU infants.</p

Variational Principles for Stellar Structure

The four equations of stellar structure are reformulated as two alternate pairs of variational principles. Different thermodynamic representations lead to the same hydromechanical equations, but the thermal equations require, not the entropy, but the temperature as the thermal field variable. Our treatment emphasizes the hydrostatic energy and the entropy production rate of luminosity produced and transported. The conceptual and calculational advantages of integral over differential formulations of stellar structure are discussed along with the difficulties in describing stellar chemical evolution by variational principles.Comment: 28 pages, LaTeX, requires AASTeX, 1 PostScript figure, revisions: erratum; accepted by Astrophysical Journa

Nonequilibrium corrections in the pressure tensor due to an energy flux

The physical interpretation of the nonequilibrium corrections in the pressure tensor for radiation submitted to an energy flux obtained in some previous works is revisited. Such pressure tensor is shown to describe a moving equilibrium system but not a real nonequilibrium situation.Comment: 4 pages, REVTeX, Brief Report to appear in PRE Dec 9

How to state general qualitative facts in Psychology?

International audienceIn what form should qualitative psychological statements have to be in order to be general and falsifiable? I show how basic qualitative measurement systems can be defined that allow for the detection and testing of general relational facts of the if-then form in a well-defined range of potential qualitative, static or dynamic, multivariate observations. The formal framework permits the pointing out of general research problems falling under the scope of empirical investigation

Understanding the planning challenges of brownfield development in coastal urban areas of England

Available in Pearl https://pearl.plymouth.ac.uk/handle/10026.1/4528 deposited 20/4/1

Comparing multifocal pupillographic objective perimetry (mfPOP) and multifocal visual evoked potentials (mfVEP) in retinal diseases

Multifocal pupillographic objective perimetry (mfPOP) shows regions of slight hypersensitivity away from retinal regions damaged by diabetes or age-related macular degeneration (AMD). This study examines if such results also appear in multifocal visual evoked potentials (mfVEPs) recorded on the same day in the same patients. The pupil control system receives input from the extra-striate cortex, so we also examined evidence for such input. We recruited subjects with early type 2 diabetes (T2D) with no retinopathy, and patients with unilateral exudative AMD. Population average responses of the diabetes patients, and the normal fellow eyes of AMD patients, showed multiple regions of significant hypersensitivity (p < 0.05) on both mfPOP and mfVEPs. For mfVEPs the occipital electrodes showed fewer hypersensitive regions than the surrounding electrodes. More advanced AMD showed regions of suppression becoming centrally concentrated in the exudative AMD areas. Thus, mfVEP electrodes biased towards extra-striate cortical responses (surround electrodes) appeared to show similar hypersensitive visual field locations to mfPOP in early stage diabetic and AMD damage. Our findings suggest that hypersensitive regions may be a potential biomarker for future development of AMD or non-proliferative diabetic retinopathy, and may be more informative than visual acuity which remains largely undisturbed during early disease