How many bird extinctions have we prevented?

How many good antidepressant medications have we missed?

The current methodology used to assess the clinical efficacy of antidepressant candidate drugs has been plagued in recent years by the failure of over 50% of controlled trials to separate placebo from established antidepressants and experimental medications. In contrast, a “negative” trial is one in which the active comparator, but not the antidepressant candidate, is significantly better than ...

How Do We Have Feelings?

For centuries, the question of how a physical structure (the brain) generates the subjective feeling of consciousness has plagued neuroscientists, physiologists, psychologists, linguists, and philosophers. This has become known as the “hard problem of consciousness” and has been the subject of many publications. Although lots of answers have been proposed, none has been completely satisfactory....

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?