Do nations' mental health policies, programs and legislation influence their suicide rates? An ecological study of 100 countries

Objective: To test the hypothesis that the presence of national mental health policies, programs and legislation would be associated with lower national suicide rates. Method: Suicide rates from 100 countries were regressed on mental health policy, program and legislation indicators. Results: Contrary to the hypothesized relationship, the study found that after introducing mental health initiatives (with the exception of substance abuse policies), countries' suicide rates rose. Conclusion: It is of concern that most mental health initiatives are associated with an increase in suicide rates. However, there may be acceptable reasons for the observed findings, for example initiatives may have been introduced in areas of increasing need, or a case-finding effect may be operating. Data limitations must also be considered.

Dual-symmetric Lagrangians in quantum electrodynamics: I. Conservation laws and multi-polar coupling

By using a complex field with a symmetric combination of electric and magnetic fields, a first-order covariant Lagrangian for Maxwell's equations is obtained, similar to the Lagrangian for the Dirac equation. This leads to a dual-symmetric quantum electrodynamic theory with an infinite set of local conservation laws. The dual symmetry is shown to correspond to a helical phase, conjugate to the conserved helicity. There is also a scaling symmetry, conjugate to the conserved entanglement. The results include a novel form of the photonic wavefunction, with a well-defined helicity number operator conjugate to the chiral phase, related to the fundamental dual symmetry. Interactions with charged particles can also be included. Transformations from minimal coupling to multi-polar or more general forms of coupling are particularly straightforward using this technique. The dual-symmetric version of quantum electrodynamics derived here has potential applications to nonlinear quantum optics and cavity quantum electrodynamics.

Sociodemographic backgrounds and career decisions of Australian and New Zealand dental students

This article describes the sociodemographic and career selection characteristics of dental students in Australia and New Zealand. A total of 672 dental students participated in the study. The survey covered age, language proficiency, type of school attended, place of residence, parental occupation, and level of education. The respondents had an average age of twenty-two years, with a range of eighteen to fifty. Fifty-six percent of respondents were female, and approximately half had completed secondary education in private schools with 44.3 percent having finished in public schools. The majority of students lived with their parents, with only a few respondents reporting a rural home address (6.8 percent). The majority of students (65.3 percent) had placed dentistry as their first career choice and had most likely made the decision after leaving high school or near the end of high school (81.4 percent), with self-motivation being the major influence on their decision. This study provides a description of the sociodemographic profile of Australian and New Zealand dental students and provides a better understanding of career decision issues. It also highlights areas for further investigation and management by educational institutions and public policy.