The polynomial birth-death (PBD) distribution on non-negative integers introduced in Brown & Xia (2001) is the equilibrium distribution of the birth-death process with birth rates {αi} and death rates {βi}, where αi ≥ 0 and βi ≥ 0 are polynomial functions of i. The family unifies many well-known distributions such as Poisson, negative binomial and binomial. In this talk, I’ll explain how a nice...

BACKGROUND Anogenital distance (AGD) is sexually dimorphic in rodents and humans, being 2- to 2.5-fold greater in males. It is a reliable marker of androgen and antiandrogen effects in rodent reproductive toxicologic studies. Data on AGD in humans are sparse, with no longitudinal data collected during infancy. OBJECTIVE This study was designed to determine AGD from birth to 2 years in males a...

BACKGROUND Efforts to reduce neonatal mortality are essential if the Millennium Development Goal (MDG) 4 is to be met. The impact of spatial dimensions of neonatal survival has not been thoroughly investigated even though access to good quality delivery care is considered to be one of the main priorities when trying to reduce neonatal mortality. This study examined the association between dista...

Fine particulate matter (PM2.5) measured at a given location is a mix of pollution generated locally and pollution traveling long distances in the atmosphere. Therefore, the identification of spatial scales associated with health effects can inform on pollution sources responsible for these effects, resulting in more targeted regulatory policy. Recently, prediction methods that yield high-resol...

Dispersal is a key component of a species's ecology and will be under different selection pressures in different parts of the range. For example, a long-distance dispersal strategy suitable for continuous habitat at the range core might not be favoured at the margin, where the habitat is sparse. Using a spatially explicit, individual-based, evolutionary simulation model, the dispersal strategie...

IZA DP No. 10952 AUGUST 2017 Did Parental Involvement Laws Grow Teeth? The Effects of State Restrictions on Minors’ Access to Abortion* We compile data on the locations of abortion providers and enforcement of parental involvement laws to document dramatic increases in the distances minors must travel if they wish to obtain an abortion without involving a parent or judge. Between 1992 – the yea...

Individual-based models of chemical or biological dynamics usually consider individual entities diffusing in space and performing a birth-death type dynamics. In this work we study the properties of a model in this class where the birth dynamics is mediated by the local, within a given distance, density of particles. Groups of individuals are formed in the system and in this paper we concentrat...

BACKGROUND The effects of ambient air pollution on pregnancy outcomes are under debate. Previous studies have used different air pollution exposure assessment methods. The considerable traffic-related intra-urban spatial variation needs to be considered in exposure assessment. Residential proximity to traffic is a proxy for traffic-related exposures that takes into account within-city contrasts...