Estimating Quantile Families of Loss Distributions for Non-Life Insurance Modelling via L-moments

This paper discusses different classes of loss models in non-life insurance settings. It then overviews the class Tukey transform loss models that have not yet been widely considered in non-life insurance modelling, but offer opportunities to produce flexible skewness and kurtosis features often required in loss modelling. In addition, these loss models admit explicit quantile specifications which make them directly relevant for quantile based risk measure calculations. We detail various parameterizations and sub-families of the Tukey transform based models, such as the g-and-h, g-and-k and g-and-j models, including their properties of relevance to loss modelling. One of the challenges with such models is to perform robust estimation for the loss model parameters that will be amenable to practitioners when fitting such models. In this paper we develop a novel, efficient and robust estimation procedure for estimation of model parameters in this family Tukey transform models, based on L-moments. It is shown to be more robust and efficient than current state of the art methods of estimation for such families of loss models and is simple to implement for practical purposes.Comment: 42 page

New physics with the compact linear collider

Probing beyond the established picture of particle physics will require some radical rethinking of accelerator designs. If accelerators are to reach the ever-higher energies that theorists would dearly like to see explored, the technological spin-offs of this engineering feat could be as surprising as the new subatomic physics

Molecular Subtypes and Personalized Therapy in Metastatic Colorectal Cancer

Development of colorectal cancer occurs via a number of key pathways, with the clinicopathological features of specific subgroups being driven by underlying molecular changes. Mutations in key genes within the network of signalling pathways have been identified; however, therapeutic strategies to target these aberrations remain limited. As understanding of the biology of colorectal cancer has improved, this has led to a move toward broader genomic testing, collaborative research and innovative, adaptive clinical trial design. Recent developments in therapy include the routine adoption of wider mutational spectrum testing prior to use of targeted therapies and the first promise of effective immunotherapy for colorectal cancer patients. This review details current biomarkers in colorectal cancer for molecular stratification and for treatment allocation purposes, including open and planned precision medicine trials. Advances in our understanding, therapeutic strategy and technology will also be outlined

Evolutionary history of the ADRB2 gene in humans

No abstract available

Steroid hormone receptors in the developing brain

Sex differences exist in the behavioral patterns of adult vertebrate species. Many of these behavioral differences arise as a, result of the developmental imprinting of sex specific patterns in the anatomical, biochemical and molecular substrates of the brain. It is well established that steroid hormones play an important role during critical periods of development to organize the brain to a male or female specific pattern. In order to demonstrate that these hormones can act directly on brain tissue, ligand specific receptors for estrogen and androgen have been demonstrated in the developing brain, using a variety of techniques. Each class of steroid hormone receptor exhibits a unique distribution in the brain. Furthermore, each receptor undergoes a unique and tissue specific ontogenetic pattern of expression. A careful examination of the distribution and ontogeny of expression allows one to formulate specific hypotheses regarding the role of each of these receptors in the development and maturation of the brain.Biomedical Reviews 1997; 7: 51-66

Energies and wave functions for a soft-core Coulomb potential

For the family of model soft Coulomb potentials represented by V(r) = -\frac{Z}{(r^q+\beta^q)^{\frac{1}{q}}}, with the parameters Z>0, \beta>0, q \ge 1, it is shown analytically that the potentials and eigenvalues, E_{\nu\ell}, are monotonic in each parameter. The potential envelope method is applied to obtain approximate analytic estimates in terms of the known exact spectra for pure power potentials. For the case q =1, the Asymptotic Iteration Method is used to find exact analytic results for the eigenvalues E_{\nu\ell} and corresponding wave functions, expressed in terms of Z and \beta. A proof is presented establishing the general concavity of the scaled electron density near the nucleus resulting from the truncated potentials for all q. Based on an analysis of extensive numerical calculations, it is conjectured that the crossing between the pair of states [(\nu,\ell),(\nu',\ell')], is given by the condition \nu'\geq (\nu+1) and \ell' \geq (\ell+3). The significance of these results for the interaction of an intense laser field with an atom is pointed out. Differences in the observed level-crossing effects between the soft potentials and the hydrogen atom confined inside an impenetrable sphere are discussed.Comment: 13 pages, 5 figures, title change, minor revision