llc: a collection of R functions for fitting a class of Lee-Carter mortality models using iterative fitting algorithms

We implement a specialised iterative regression methodology in R for the analysis of age-period mortality data based on a class of generalised Lee-Carter (LC) type modelling structures. The LC-based modelling frameworks is viewed in the current literature as among the most efficient and transparent methods of modelling and projecting mortality improvements. Thus, we make use of the modelling approach discussed in Renshaw and Haberman (2006), which extends the basic LC model and proposes to make use of a tailored iterative process to generate parameter estimates based on Poisson likelihood. Furthermore, building on this methodology we develop and implement a stratified LC model for the measurement of the additive effect on the log scale of an explanatory factor (other than age and time). This modelling methodology is implemented in a publically available collection of programming functions that facilitate both the preparation of mortality data and the fitting and analysis of the given log-linear modelling structures. Also, the package incorporates methods to produce forecasts of future mortality rates and to compute the corresponding future life expectancy

A comparative study of parametric mortality projection models

The relative merits of different parametric models for making life expectancy and annuity value predictions at both pensioner and adult ages are investigated. This study builds on current published research and considers recent model enhancements and the extent to which these enhancements address the deficiencies that have been identified of some of the models. The England & Wales male mortality experience is used to conduct detailed comparisons at pensioner ages, having first established a common basis for comparison across all models. The model comparison is then extended to include the England & Wales female experience and both the male and female USA mortality experiences over a wider age range, encompassing also the working ages

2-Azido-1-(4-nitro­phen­yl)ethanone

In the title compound, C8H6N4O3, the ketone [C—C(=O)—C] and nitro groups are tilted with respect to the benzene ring by 18.92 (6) and 24.11 (15)°, respectively. In the crystal, mol­ecules are linked into inter­woven chains running parallel to the [100] direction by C—H⋯N hydrogen bonds and weak π–π stacking inter­actions, with centroid–centroid separations of 3.897 (3) Å

2-Azido-1-(4-methyl­phen­yl)ethanone

In the mol­ecule of the title compound, C9H9N3O, the angle formed by the least-squares line through the azide group with the normal to the plane of the benzene plane ring is 46.62 (16)°. The crystal structure features C—H⋯O hydrogen bonds, which link the mol­ecules into zigzag chains running parallel to [010]

Role of key players in paradigm shifts of prostate cancer bone metastasis

Prostate cancer is one of the most common human cancers and bone metastasis is a frequent finding in the natural history of several types of cancers. The molecular mechanisms that makes prostate cancer metastasize to bone have recently been identified, and provide new molecular targets for drug development, several biochemical by-products that provide insight into the tumorbone interaction, with potential to enhance the clinical management of patients with bone metastases, have been reported during the past decade, however, its anticipated risk, diagnosis and response to therapy are still challenging to assess in clinical practice. In this article, we will discuss these challenges with an emphasis on the communication pathways between each cell type involved and the roles of Wnts, sclerostin, RANKL, PTHrP and macrophages