Cultural imagery and statistical models of the force of mortality: Addison, Gompertz and Pearson

We describe selected artistic and statistical depictions of the force of mortality (hazard or mortality rate), which is a concept that has long preoccupied actuaries, demographers and statisticians. We provide a more graphic form for the force-of-mortality function that makes the relationship between its constituents more explicit. The 'Bridge of human life' in Addison's allegorical essay of 1711 provides a particularly vivid image, with the forces depicted as external. The model that was used by Gompertz in 1825 appears to treat the forces as internal. In his 1897 essay Pearson mathematically modernized 'the medieval conception of the relation between Death and Chance' by decomposing the full mortality curve into five distributions along the age axis, the results of five 'marksmen' aiming at the human mass crossing this bridge. We describe Addison's imagery, comment briefly on Gompertz's law and the origin of the term 'force of mortality', describe the background for Pearson's essay, as well as his imagery and statistical model, and give the bridge of life a modern form, illustrating it via statistical animation

An extension to the Navier-Stokes equations to incorporate gas molecular collisions with boundaries

We investigate a model for micro-gas-flows consisting of the Navier-Stokes equations extended to include a description of molecular collisions with solid boundaries, together with first and second order velocity slip boundary conditions. By considering molecular collisions affected by boundaries in gas flows we capture some of the near-wall affects that the conventional Navier-Stokes equations with a linear stress/strain-rate relationship are unable to describe. Our model is expressed through a geometry-dependent mean-free-path yielding a new viscosity expression, which makes the stress/strain-rate constitutive relationship non-linear. Test cases consisting of Couette and Poiseuille flows are solved using these extended Navier-Stokes equations, and we compare the resulting velocity profiles with conventional Navier-Stokes solutions and those from the BGK kinetic model. The Poiseuille mass flow-rate results are compared with results from the BGK-model and experimental data, for various degrees of rarefaction. We assess the range of applicability of our model and show that it can extend the applicability of conventional fluid dynamic techniques into the early continuum-transition regime. We also discuss the limitations of our model due to its various physical assumptions, and we outline ideas for further development

Modulation of porcine β-defensins 1 and 2 upon individual and combined Fusarium toxin exposure in a swine jejunal epithelial cell line

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Physical and match performance of female soccer players

The English Football Association (FA) reported female soccer was the nation’s number one team sport for female sport participation (1.38 m). There is no research on physical- and match- performance of female soccer players in England at the elite level and no investigations in to the new re-structure that the English FA made in 2011 for both senior and youth levels. Therefore, the overarching aim of this research thesis was to develop physical performance and match performance profiles of female soccer players in England across senior and youth players at both elite and non-elite levels of play

Special Issue Call for Papers: Creativity in Mathematics

The Journal of Humanistic Mathematics is pleased to announce a call for papers for a special issue on Creativity in Mathematics. Please send your abstract submissions via email to the guest editors by March 1, 2019. Initial submission of complete manuscripts is due August 1, 2019. The issue is currently scheduled to appear in July 2020

Spectrophotofluorometric determination of estrogens in the urine and feces of cows during different stages of pregnancy

... the bulletin reports on Department of Dairy Husbandry Research project no. 28 'Hormone Enzyme'--P. [2].Digitized 2007 AES.Includes bibliographical references (pages 41-48)

The effects of short pulse laser surface cleaning on porosity formation and reduction in laser welding of aluminium alloy for automotive component manufacture

Laser welding of aluminium alloys typically results in porosity in the fusion zones, leading to poor mechanical and corrosion performances. Mechanical and chemical cleaning of surfaces has been used previously to remove contaminants for weld joint preparations. However, these methods are slow, ineffective (e.g. due to hydrogen trapping) or lead to environmental hazards. This paper reports the effects of short pulsed laser surface cleaning on porosity formation and reduction in laser welding of AC-170PX (AA6014) aluminium sheets (coated with Ti/Zr and lubricated using a dry lubricant AlO70) with two types of joints: fillet edge and flange couch, using an AA4043 filler wire for automotive component assembly. The effect of laser cleaning on porosity reduction during laser welding using a filler wire has not been reported before. In this work, porosity and weld fusion zone geometry were examined prior to and after laser cleaning. The nanosecond pulsed Nd:YAG laser cleaning was found to reduce porosity significantly in the weld fusion zones. For the fillet edge welds, porosity was reduced to less than 0.5% compared with 10–80% without laser cleaning. For flange couch welds, porosity was reduced to 0.23–0.8% with laser cleaning from 0.7% to 4.3% without laser cleaning. This has been found to be due to the elimination of contaminations and oxide layers that contribute to the porosity formation. The laser cleaning is based on thermal ablation

Multimodality imaging of Abernethy malformation

Abernethy malformation, or congenital extrahepatic portosystemic venous shunt, is a rare anomaly involving the portal venous system. Despite its rarity, it is increasingly being reported, and therefore, it is important to diagnose given the potential adverse clinical consequences if left untreated. It has a spectrum of presentations, ranging from complete lack of symptoms, to causing hepatic carcinoma, hepatic encephalopathy, severe pulmonary hypertension, and diffuse pulmonary arteriovenous malformation. We herein describe the case and echocardiographic, computed tomography, and magnetic resonance imaging findings of a transgender individual, with this anomaly detected incidentally during adulthood