How Many Legs Does a Bear Have?

How Many Rational Points Does a Random Curve Have?

A large part of modern arithmetic geometry is dedicated to or motivated by the study of rational points on varieties. For an elliptic curve over Q, the set of rational points forms a finitely generated abelian group. The ranks of these groups, when ranging over all elliptic curves, are conjectured to be evenly distributed between rank 0 and rank 1, with higher ranks being negligible. We will de...

How Many Legs Do I Have? Non-Simple Roles in Number Restrictions Revisited

The Description Logics underpinning OWL impose a well-known syntactic restriction in order to preserve decidability: they do not allow to use nonsimple roles—that is, transitive roles or their super-roles—in number restrictions. When modeling composite objects, for example in bio-medical ontologies, this restriction can pose problems. Therefore, we take a closer look at the problem of counting ...

How many species have mass M?

Within large taxonomic assemblages, the number of species with adult body mass M is characterized by a broad but asymmetric distribution, with the largest mass being orders of magnitude larger than the typical mass. This canonical shape can be explained by cladogenetic diffusion that is bounded below by a hard limit on viable species mass and above by extinction risks that increase weakly with ...

Perspective. How many women have osteoporosis?

Osteoporosis is widely viewed as a major public health concern, but the exact magnitude of the problem is uncertain and likely to depend on how the condition is defined. Noninvasive bone mineral measurements can be used to define a state of heightened fracture risk (osteopenia), or the ultimate clinical manifestation of fracture can be assessed (established osteoporosis). If bone mineral measur...

How many doctors should Sri Lanka have?