Standard models of molecular evolution cannot estimate absolute speciation times alone, and require external calibrations to do so, such as fossils. Because fossil calibration methods rely on the incomplete fossil record, a great number of nodes in the tree of life cannot be dated precisely. However, many major paleogeographical events are dated, and since biogeographic processes depend on pale...

The aim of this paper is to assess the possible consequences of adolescent physical, emotional and sexual dating violence through a review of the literature on the topic. An electronic search of major biomedical bibliographic databases (Pubmed, ISI, PsycINFO) was used to retrieve articles providing information on the prevalence rates, risk factors, associated consequences and possible preventiv...

OBJECTIVE This multi-method, longitudinal study examines the negotiation of autonomy and relatedness between teens and their mothers as etiologic predictors of perpetration and victimization of dating aggression two years later. METHOD Observations of 88 mid-adolescents and their mothers discussing a topic of disagreement were coded for each individual's demonstrations of autonomy and related...

Media attention and the literature on lesbian, gay, and bisexual youth overwhelmingly focus on violence involving hate crimes and bullying, while ignoring the fact that vulnerable youth also may be at increased risk of violence in their dating relationships. In this study, we examine physical, psychological, sexual, and cyber dating violence experiences among lesbian, gay, and bisexual youth--a...

Although prior research has examined how individual difference factors are related to relationship initiation and formation over the Internet (e.g., online dating sites, social networking sites), little research has examined how dispositional factors are related to other aspects of online dating. The present research therefore sought to examine the relationship between several dispositional fac...

There are limited empirical investigations that directly compare men and women's motivations, or reasons, for perpetrating physical dating violence (DV). In an attempt to further understand whether men and women have similar or different motives for physical DV, the purpose of the current study was to conduct a gender comparison of motives in a sample of male (n = 163) and female (n = 319) coll...

The Doppler effect has well-established applications in astronomy, medicine, radar and metrology. Recently, a number of experimental demonstrations of the inverse Doppler effect have begun to appear. However, the inverse Doppler effect has never been observed on an electronically reconfigurable system with an external electromagnetic wave source at radio frequencies (RF) in experiment. Here we ...

W ithin a decade of the discovery of radioactivity in 1896, the chemical elements uranium, radium, polonium, and thorium were recognized as radioactive; the basic theory, mechanisms, and mathematics of radioactive decay were established; decay rates of some radioactive chemical elements were determined; and the ages of two mineral specimens were calculated for the first time from their uranium ...