Large herbivore consumption of forage is known to affect vegetation composition and thereby ecosystem functions. It is thus important to understand how diet composition arises as a mixture of individual variation in preferences and environmental drivers of availability, but few studies have quantified both. Based on 10 years of data on diet composition by aid of microhistological analysis for s...

In this article, we explore the effect of public policy on the extent to which genes influence smoking desistance. Using a sample of adult twins (n(mz) = 363, n(dz) = 233) from a large population registry, we estimate Cox proportional hazards models that describe similarity in the timing of smoking desistance among adult twin pairs. We show that identical twin pairs are significantly more likel...

The relative importance of mutation, selection, and biased gene conversion to patterns of base composition variation in Drosophila melanogaster, and to a lesser extent, D. simulans, has been investigated for many years. However, genomic data from sufficiently large samples to thoroughly characterize patterns of base composition polymorphism within species have been lacking. Here, we report a ge...

Contrasting hypotheses exist about the relationship between plant species diversity and genetic diversity. However, experimental data of species diversity effects on genetic differentiation among populations are lacking. To address this, Lolium perenne was sown with an equal number of seeds in 78 experimental grasslands (Jena Experiment) varying in species richness (1, 2, 4, 8 to 16) and functi...

We introduce a general class of rules for claims problems, called the difference rules, and demonstrate that a rule satisfies composition down and composition up if and only if it is a difference rule. We show that these rules take a special form when there are two agents. In a variable population framework, we introduce a family of rules satisfying consistency, composition down, and compositio...

tehran the capital city of iran, with a population of about 8 million and an area of over 700 km2 is one of the most polluted metropolises in the world. tehran is suffering from a tremendous reduction in its sink capacity for absorption and assimilation of pollution which is generally due to uncontrolled urban sprawl and failure in consideration of ecological aspects into regional land use plan...