The shapes of sexually selected weapons differ widely among species, but the drivers of this diversity remain poorly understood. Existing explanations suggest weapon shapes reflect structural adaptations to different fighting styles, yet explicit tests of this hypothesis are lacking. We constructed finite element models of the horns of different rhinoceros beetle species to test whether functio...

PURPOSE We hypothesize that adolescents' exposure to violence and personal victimization will be associated with the frequency with which they engage in fighting behaviors. However, adolescents who are future-oriented and goal-directed and from more secure families are hypothesized to report less fighting behavior. METHODS A cross-sectional, anonymous survey was administered to 225 youths (ma...

Ten novel microsatellite markers were developed and characterized from Siamese fighting fish (Betta splendens). Nine of ten markers were polymorphic, exhibiting an allelic number (NA) from 2 to 6 alleles per locus. The effective number of alleles (NE) ranged from 1.60 to 3.08 (average of 2.30). The observed (HO) and expected (HE) heterozygosities ranged from 0.13 to 0.67 (average of 0.39) and 0...

BACKGROUND Physical fighting is an assaultive behaviour that can lead to injury. Family affluence is a health determinant that can influence injury. This study examines the relationship between family affluence and two outcomes: physical fighting and fighting-related injury in Canadian adolescents. Three measurements were used to represent family affluence and assess whether these measures demo...

Polychlorinated biphenyls (PCBs) are considered "persistent organic pollutants;" fat-soluble compounds that bioaccumulate in individuals and bio-magnify in the food chain. PCBs were the first industrial compounds to experience a worldwide ban on production because of their potent toxicity. These compounds are still present in our food supply (fish, dairy, hamburger, and poultry being the most c...

Adults, infants and non-human primates are thought to possess similar non-verbal numerical systems, but there is considerable debate regarding whether all vertebrates share the same numerical abilities. Despite an abundance of studies, cross-species comparison remains difficult because the methodology employed and the context of species examination vary considerably across studies. To fill this...

Despite documented benefits, the processes described in the new product development literature often prove difficult to follow in practice. A principal source of such difficulties is the phenomenon of fire fighting–the unplanned allocation of resources to fix problems discovered late in a product's development cycle. While it has been widely criticized, fire fighting is a common occurrence in m...