Cutaneous malignant melanoma incidence is strongly associated with European depigmented skin type regardless of ambient ultraviolet radiation levels: evidence from Worldwide population-based data

Current public health advice is that high ultraviolet radiation (UVR) exposure is the primary cause of Malignant Melanoma of skin (CMM), however, despite the use of sun-blocking products incidence of melanoma is increasing. To investigate the UVR influence on CMM incidence worldwide WHO, United Nations, World Bank databases and literature provided 182 country-specific melanoma incidence estimates, daily UVR levels, skin colour (EEL), socioeconomic status (GDP PPP), magnitude of reduced natural selection (Ibs), ageing, urbanization, percentage of European descendants (Eu%), and depigmentation (blonde hair colour), for parametric and non-parametric correlations, multivariate regressions and analyses of variance. Worldwide, UVR levels showed negative correlation with melanoma incidence ("rho" = -0.515, p < 0.001), remaining significant and negative in parametric partial correlation (r = -0.513, p < 0.001) with other variables kept constant. After standardising melanoma incidence for Eu%, melanoma correlation with UVR disappeared completely ("rho" = 0.004, p = 0.967, n = 127). The results question classical views that UVR causes melanoma. No correlation between UVR level and melanoma incidence was present when Eu% (depigmented or light skin type) was kept statistically constant, even after adjusting for other known variables. Countries with lower UVR levels and more Eu% (depigmented or light skin people) have higher melanoma incidence. Critically, this means that individual genetic low skin pigmentation factors predict melanoma risk regardless of UVR exposure levels, and even at low-UVR levels. Keywords: UV levels; adaptation; cutaneous malignant melanoma (CMM); depigmentation; incidence; world-wide data

Properties of a new quasi-axisymmetric configuration

A novel, compact, quasi-axisymmetric configuration is presented which exhibits low fast-particle losses and is stable to ideal MHD instabilities. The design has fast-particle loss rates below 8\% for flux surfaces within the half-radius, and is shown to have an MHD-stability limit of a normalised pressure of $\langle\beta\rangle=3\%$ where $\langle\beta\rangle$ is volume averaged. The flux surfaces at various plasma betas and currents as calculated using the SPEC equilibrium code are presented. Neoclassical transport coefficients are shown to be similar to an equivalent tokamak, with a distinct banana regime at half-radius. An initial coil design study is presented to assess the feasibility of this configuration as a fusion-relevant experiment

MODELLING AND PROGNOSIS OF COMPETITIVE PERFORMANCES IN ELITE SWIMMING

The study demonstrates that the performance of an elite female swimmer in the finals of the 200 m backstroke at the Olympic Games 2000 in Sydney can be predicted by means of the nonlinear mathematical method of a neural back-propagation network. The analysis included the performance output data of 19 competitions prior to the Olympics within a time period of 95 successive weeks and the training input data of the last four weeks prior to each competition. The training data were divided into two phases: (1) a two-week taper cycle, and (2) an earlier two-week high load cycle. The trained neural network was not only able to model the 19 competitive performances, but also to predict the performance in the semi final of the Olympic Games in Sydney on the basis of the two sets of training data during the preparation before that specific competition

Stress concentration factors in FRP-reinforced tubular DKT joints under axial loads

The stress concentration factors (SCFs) in uniplanar fibre-reinforced polymer (FRP) DKT joints are calculated under five axial loading conditions to determine the maximum SCFs. To this end, 108 finite element models of reinforced DKT joints with different FRPs and geometrical parameters are analysed. Available experimental data and formulas are used to validate the finite element models. The validated finite element models are utilized to investigate the effects of the FRP parameters along with different geometrical parameters on the stress concentration factors in uniplanar DKT joints. The simulations show a reduction of the maximum SCF by around 40% compared to unreinforced DKT joints. The reduction effect increases significantly with increasing the FRP thickness and the number of layers. Despite the notable efficacy of the FRP sheets on the drop of the SCFs in the X-connections, there is not any study or equation on the X-joints with FRP. Therefore, a precise equation is proposed for quantifying the SCFs in X-connections with FRP and is checked against the UK DoE acceptance standard

The rigidity of periodic body-bar frameworks on the three-dimensional fixed torus

We present necessary and sufficient conditions for the generic rigidity of body-bar frameworks on the three-dimensional fixed torus. These frameworks correspond to infinite periodic body-bar frameworks in $\mathbb{R}^3$ with a fixed periodic lattice.Comment: 31 pages, 12 figure

Quantifying asymmetry of anterior cerebral arteries as a predictor of anterior communicating artery complex aneurysm

ObjectivesThe aim of this study was to establish an anatomical index for early prediction of the risk of development of aneurysms in anterior communicating arterial complex (AcomAC). The asymmetric diameter of one anterior cerebral artery (ACA) to other could alter haemodynamics and may contribute to formation of aneurysms in AcomAC and be a reliable predictor of the risk of development of aneurysms.Design and settingThis is a retrospective, observational and quantitative study, which used cerebral computed tomography angiography (CCTA) scans in South Australia.ParticipantsCCTA scans of 166 adult patients of both sexes were studied.Main outcome measuresThe internal diameters of the proximal segments of ACAs (A1s) were measured. Position and presence or absence of aneurysms in AcomAC were determined. The ratio of A1 diameters was taken as a measure of A1 asymmetry.ResultsThe ratio of diameters of A1s correlated with the occurrence of AcomAC aneurysms. The risk of development of aneurysms in AcomAC was much greater (80%, OR=47.3) when one A1 segment’s radius was at least 50% larger (ie, 2.25 times cross-sectional area) than the other.ConclusionThe general information on asymmetric A1 has been published previously. The present findings have significant contribution since the A1s asymmetry ratios have been categorised in ascending order and matched with the presence of AcomAC aneurysms. The asymmetry ratio of the A1 is a good predictor for the development of AcomAC aneurysms. Reconstruction of the asymmetric A1 could be done if the technology gets advanced.</jats:sec

Obesity - a natural consequence of human evolution

Obesity is considered a major epidemic of the 21st century. In developed countries, about 1/3 of adults are obese and another 1/3 overweight according to the oversimplified measure - the Body Mass Index. More precise indicators of adiposity: waist circumference, skinfolds, underwater weighing and absorptiometry indicate similar levels of fatness. Obesity per se does not necessarily lead to pathological states, nor to premature mortality. Recent results of large sample studies indicate that more than 1/3 of people classified as obese by fatness indices are physiologically normal. Others, however, suffer from a number of pathological conditions, common among them being the metabolic syndrome and cardiovascular disease. The classical explanation for increasing obesity is the positive energy balance - too much food intake and too little exercise. It seems, however, that this explanation is too simplistic. In societies, and in families, exposed to overeating and lazy lifestyles, about 1/3 of individuals have normal body mass and low levels of fatness, while others become obese. There is, therefore, individual variation in propensity for obesity. We have identified two specific variables differentiating fatness. People who have large lean trunk frames - large volumes of abdominal cavities and thus large gastrointestinal tracts - put on more subcutaneous fat than those with smaller trunk frames (Henneberg and Ulijaszek 2010). This may be a result of larger volumes of food required for antral extension to release ghrelin, or larger surface area of small intestines for food absorption. The second variable is concentrations of Alanine Transaminase, an enzyme responsible for conversion of an amino acid to a carbon skeleton that can be used in fat synthesis. Our study of 46000 young Swiss males (Henneberg, Rühli, Gruber and Woitek 2011) found consistent correlation between levels of Alanine Transaminase and body weight in groups of normal body mass individuals, overweight individuals and moderately obese individuals. Coupling this finding with the fact that among vegetarians, even those living in North America with overabundance of food and low levels of exercise, obesity and overweight are much less common than among non-vegetarians, we have now hypothesized that the increased obesity of modern affluent societies is a result of consumption of animal protein when energy needs are already covered by carbohydrates and fat consumed concurrently. Until the advent of agriculture, humans relied on consumption of a variety of terrestrial and aquatic animals supplemented by relatively small amounts of plant foods. In this situation our bodies became adapted to use proteins as a source of energy, and became efficient at storing occasional surpluses of amino acids by their deamination and conversion to fats. In the modern diets carbohydrates are abundant and provide, together with fats, energy required by human bodies, proteins after deamination are efficiently converted to fats. When new types of crops are introduced to mass production of cheap foods our bodies may not be able to react correctly to all their contents and some of the ingredients may cause additional fatness. An example of widespread recent introduction of industrially processed soybean products that correlates with prevalence of obesity across countries of the world is discussed.Maciej Henneberg, James Grantha

Variation of human hairiness: a possible adaptation to solar radiation and melanin

Many theories have been advanced to explain human hairlessness, however, there is no consensus. This study of 76 males observed that skin reflectance measuring skin colouration and melanin pigmentation correlated with hair size and follicle density. Individuals with a greater concentration of melanin within the superficial layer of the skin had a lower follicle density and smaller sizes of hairs. In contrast, individuals with a lower melanin concentration and lighter skin colour had a full range of hairiness. This leads to the suggestion that over the course of human evolution, high concentrations of melanin in consistently exposed to ultraviolet radiation areas developed first and that hair loss was a consequence of competition in the skin between melanin production and hair growth. Darker pigmented skin and lower follicle density are significantly correlated (R2=0.283; p<0.05). Individuals with darker skin had a mean of 4.91 follicles per cm2 whereas those with lighter skin reflectance had 11.20 follicles per cm2. This suggests that increased concentrations of melanin in the basal layer of the epidermis may limit hairiness by negatively influencing the skin's ability to produce hair.Amrita Dhugga, Maciej Henneberg, Jaliya Kumaratilak

Circling in on convective organization

Cold pools (CPs) contribute to convective organization. However, it is unclear by which mechanisms organization occurs. By using a particle method to track CP gust fronts in large eddy simulations, we characterize the basic collision modes between CPs. Our results show that CP interactions, where three expanding gust fronts force an updraft, are key at triggering new convection. Using this, we conceptualize CP dynamics into a parameter‐free mathematical model: circles expand from initially random points in space. Where two expanding circles collide, a stationary front is formed. However, where three expanding circles enclose a single point, a new expanding circle is seeded. This simple model supports three fundamental features of CP dynamics: precipitation cells constitute a spatially interacting system; CPs come in generations; and scales steadily increase throughout the diurnal cycle. Finally, this model provides a framework for how CPs act to cause convective self‐organization, clustering, and extremes