An assessment of PenSim2

The Department for Work and Pensions (DWP)’s Pensim2 model is a dynamic microsimulation model. The principal purpose of this model is to estimate the future distribution of pensioner incomes, thus enabling analysis of the distributional effects of proposed changes to pension policy. This paper presents the results of an assessment of Pensim2 by researchers at the IFS. We start by looking at the overall structure of the model, and how it compares with other dynamic policy analysis models across the world. We make recommendations at this stage as to how the overall modelling strategy could be improved. We then go on to analyse the characteristics of most of the individual modules which make up Pensim2, examining the data used and the regression and predictions used in each step. The results from this examination are used to formulate a set of short and medium-term recommendations for developing and improving the model. Finally, we look at what might become possible for the model over a much longer time frame – looking towards developing a ‘Pensim3’ model over the next decade or so

Explorations into the rare earth chemistry of biphenolates and superbulky cyclopentadienyl ligands, and a study of C-F activation by rare earth metals

Angus Shephard studied a range of alternative synthetic methods for accessing valuable rare earth metal complexes. He explored new and previously unused methods of synthesising rare earth biphenolate complexes, superbulky lanthanoid metallocene complexes, and lanthanoid formamidinate and pyrazolate species. His work has provided fundamental insight into the reactivity of free rare earth metals

Des coloriages de pavages super et superbes

II existe une vaste littérature sur le sujet des groupes de couleurs et des coloriages des motifs dans le plan [2, chapitre 8], [6], [8]. II est toutefois étrange qu’aucun de ces travaux ne semble porter directement sur les problèmes du coloriage des pavages comme tel. Plus particulièrernent, bien que les groupes de couleurs soient souvent présentés comme des groupes de symétrie de couleurs des pavages, un examen approfondi révélera que ce ne sont que les motifs des pavés du pavage qui sont considérés; d’autres propriétés essentielles d’un pavage tel que son type topologique et I’adjacence de certaines paires de pavés sont ignorées. Si, par contre, on en tient compte, plusieurs problèmes intéressants (et complexes) se présentent. Le but de cet article est d’aborder quelques-uns de ces problèmes. On s’intéressera plus particulièrement à ce qu’on appelle les super coloriages de pavages isoédriques. (On expliquera ci-dessous les termes essentiels.) Au-delà de I’intérêt mathématique, les super coloriages sont très attrayants d’un point devue esthétique et, à ce titre, ils ont été utilisés par des artistes comme M.C. Escher. En fait dans I’ensemble des collections publiées d’oeuvres d’Escher, tous les coloriages de pavages isoédriques sont super. (On peut consulter, par exemple, [ 1 , Planches E2-E23, E32-E31, E36-E51, E55, E62-E66, E70, E73-E79, E86, E88-E92, E94-E98, E l 02-E109, E116-E119, E124, E127, E128].) Ce fait fut à I’origine du présent article, il est la suite d’une présentation de I’auteur au Escher Symposium de Rome en mars 1985 (un rapport en a été donné dans les Comptes-rendus de cette rencontre [7]). Toutefois, dans I’intérêt du lecteur, on répétera ici la terminologie jugée essentielle et cette présentation sera auto-suffisante. L’auteurtient à exprimer sa reconnaissance à Marjorie Senechal et à Tom Wieting pour hi avoir suggéré les corrections à [6], et, plus particulièrement a Branko Grünbaum pour nos discussions utiles et les commentaires qu’il porta sur les versions préliminaires de cet article, commentaires qui menèrent à plusieurs améliorations.There exists an extensive literature concerning colour groups and the related colourings of the motifs of a plane pattern [2, Chapter 81, [6], [8]. It is strange that none of this work seems to refer directly to the problems of colouring tilings as such. To be more specific, though colour groups are often displayed as the colour symmetry groups of tilings, careful examination will show that it is only the patterns of the tiles in the tilings which are under consideration; other essential properties of a tiling such as its topological type, and the adjacencies of certain pairs of tiles, are ignored. If the latter are taken into account, several interesting (and difficult) problems emerge. It is the purpose of the present paper to consider some of these. In particular, we shall be concerned with what are called super colourings of isohedral tilings. (These words and other essential terminology, will be explained shortly.) Besides being mathematically interesting, super colourings are very attractive from an aesthetic point of view, and have been used by artists such as M.C. Escher. In fact, in the published collections of Escher’s works, all his colourings of isohedral tilings are super. (See, for example, [ l , Plates E2-E23, E32-E31, E36-E51, E55, E62-E66, E70, E73-E79, E86, E88-E92, E94-E98, E102-E109, E l 16-El 19, E 124, E 127, E 1281.) This fact motivated the present paper, which isasequel to the talkgiven bythe authoratthe ExherSymposium in Rome in March 1985, and reported in the Proceedings of that meeting [7]. However, for the convenience of the reader, essential terminology will be repeated here and the presentation will be self-contained. The author wishes to express his gratitude to Marjorie Senechal and Tom Wieting for supplying him with corrections to [6], and, more especially to Branko Grunbaum for helpful discussions and for his comments on preliminary versions of this paper which led to many improvements.Peer Reviewe

Flexible delivery of Er:YAG radiation at 2.94 µm with negative curvature silica glass fibers:a new solution for minimally invasive surgical procedures

We present the delivery of high energy microsecond pulses through a hollow-core negative-curvature fiber at 2.94 µm. The energy densities delivered far exceed those required for biological tissue manipulation and are of the order of 2300 J/cm(2). Tissue ablation was demonstrated on hard and soft tissue in dry and aqueous conditions with no detrimental effects to the fiber or catastrophic damage to the end facets. The energy is guided in a well confined single mode allowing for a small and controllable focused spot delivered flexibly to the point of operation. Hence, a mechanically and chemically robust alternative to the existing Er:YAG delivery systems is proposed which paves the way for new routes for minimally invasive surgical laser procedures

Male Circumcision and Risky Sexual Behavior in Zimbabwe: Evidence from the 2010-11 Zimbabwe Demographic and Health Survey

In 2009, Zimbabwe adopted voluntary medical male circumcision (VMMC) as an additional method of HIV prevention. The promotion of VMMC has raised a major concern that it might lead to an increase in high-risk sexual behavior, a phenomenon known as risk compensation or behavioral disinhibition. This study sought to test whether circumcised men in Zimbabwe are more likely to have engaged in risky sexual behavior. The study used data collected from 7,480 men age 15-54 who were interviewed during the 2010-11 Zimbabwe Demographic and Health Survey (ZDHS). Logistic regression was used to assess the association between circumcision and risky sexual behaviors. The study found no statistically significant association between male circumcision and risky sexual behavior. These results suggest a need to continue monitoring the relationships between ongoing VMCC campaigns and men’s risky sexual behavior. Information dissemination on VMMC should emphasize caution in messages promoting medical male circumcision to avoid giving the impression that it provides immunity against HIV