Abstinence-Only-Until-Marriage: An Updated Review of U.S. Policies and Programs and Their Impact.

Adolescence is marked by the emergence of human sexuality, sexual identity, and the initiation of intimate relations; within this context, abstinence from sexual intercourse can be a healthy choice. However, programs that promote abstinence-only-until-marriage (AOUM) or sexual risk avoidance are scientifically and ethically problematic and-as such-have been widely rejected by medical and public health professionals. Although abstinence is theoretically effective, in actual practice, intentions to abstain from sexual activity often fail.

Invited commentary: broadening the evidence for adolescent sexual and reproductive health and education in the United States.

Scientific research has made major contributions to adolescent health by providing insights into factors that influence it and by defining ways to improve it. However, US adolescent sexual and reproductive health policies-particularly sexuality health education policies and programs-have not benefited from the full scope of scientific understanding. From 1998 to 2009, federal funding for sexuality education focused almost exclusively on ineffective and scientifically inaccurate abstinence-only-until-marriage (AOUM) programs.

Abstinence and teenagers: prevention counseling practices of health care providers serving high-risk patients in the United States.

Context: Abstinence-only education has had little demonstrable impact on teenagers' sexual behaviors, despite significant policy and funding efforts. Given the struggle over resources to improve teenagers' reproductive health outcomes, the views of clinicians serving teenagers at high risk for unintended pregnancy and STDs merit particular attention.

Methods: In 2005, a qualitative study with 31 clinicians serving low-income, at-risk patients was conducted.

"I wouldn't be this firm if I didn't care": preventive clinical counseling for reproductive health.

Objective: This qualitative study of health care clinicians serving women at heightened risk of sexually transmitted infections and unintended pregnancy was undertaken to explore concepts underlying reproductive health counseling messages in clinical encounters.

Methods: In-depth interviews were conducted with 31 clinicians, including physicians and advanced practice nurses serving primarily low-income patients in high-risk communities throughout the U.S.

Molecular basis of intracistronic complementation in the Passover locus of Drosophila.

The only demonstrated mechanism for intracistronic genetic complementation requires physical interaction of protein subunits to create a functional molecule. We demonstrate another and perhaps quite general mechanism utilizing proteins with unique and shared domains. The Drosophila neural mutant Passover (Pas) disrupts specific synaptic connections.

The Passover locus in Drosophila melanogaster: complex complementation and different effects on the giant fiber neural pathway.

Drosophila melanogaster bearing the Passover mutation fail to jump in response to a light-off stimulus. Pas also disrupts some of the synapses between the neurons of the giant fiber system which mediate this escape behavior. We have mapped Pas to the 19E subdivision of the polytene X chromosome.

DNA sequence analysis of X-ray-induced deletions at the white locus of Drosophila melanogaster.

We have determined the nucleotide sequence of 5 X-ray-induced white mutants containing small rearrangements. Comparison with wild-type sequences showed deletions in the coding region ranging in size between 6 bp and 29 bp. These small deletions are distributed non-randomly over the white locus.

The nature of radiation-induced mutations at the white locus of Drosophila melanogaster.

X-Ray- and neutron-induced mutations at the white locus of Drosophila melanogaster were used to study the nature of radiation-induced genetic damage. Genetic analysis showed the presence of multi-locus deficiencies in 15 out of 31 X-ray mutants and in 26 out of 35 mutants induced by neutrons. The DNA from 11 X-ray and 4 neutron mutants, which were not multi-locus deficiencies, was analyzed by Southern blot-hybridization.

Distribution of MR-induced sex-linked recessive lethal mutations in Drosophila melanogaster.

In the 'doubling-dose' method currently used in genetic risk evaluation, two principle assumptions are made and these are: (1) there is proportionality between spontaneous and induced mutations and (2) the lesions that lead to spontaneous and induced mutations are essentially similar. The studies reported in this paper were directed at examining the validity of these two assumptions in Drosophila. An analysis was made of the distribution of sex-linked recessive lethals induced by MR, one of the well-studied mutator systems in Drosophila.

High proportion of multi-locus deletions among hycanthone-induced X-linked recessive lethals in Drosophila melanogaster.

328 X-linked recessive lethal mutations induced in late spermatids by hycanthone methanesulfonate were tested for coverage by duplications that comprised, in total, about 24% of the euchromatic X chromosome; 78 lethals appeared to be covered. Crossover localization tests of a random sample of 38 non-covered lethals revealed 4 chromosomes carrying a lethal within a duplicated segment. Lethals localized to a particular region were crossed to reference deficiencies and single-locus mutations, and inter se, to ascertain their genetic extent.

Neutron- and X-ray-induced mutations at the yellow, white, forked and vermilion loci of Drosophila melanogaster; a preliminary analysis.

Neutrons and X-rays were used to induce mutations at the yellow, white, vermilion and forked loci of Drosophila melanogaster by irradiation of spermatozoa in males. The mutations were characterized for the presence and location of simultaneously induced rearrangements and recessive lethal mutations. F1 females carrying induced visible mutations were identified, described and tested for fertility.

The genetic analysis of D. melanogaster heterochromatin.

Classical, or constitutive (Brown, 1966), heterochromatin is a nearly ubiquitous aspect of higher eukaryotic chromosome structure and its genetic significance has been debated since its first description (Heitz, 1928, 1929). This review describes genetic studies on the heterochromatin of Drosophila and the perspectives they provide on the possible biological role(s) of constitutive heterochromatin. In addition to documenting the existence of gene loci within heterochromatin, these studies provide evidence for long-range interactions within the nucleus and involving heterochromatin.

Evaluation and re-evaluation of genetic radiation hazards in man. I. Interspecific comparison of estimates of mutation rates.

A detailed presentation is made of the experimental data from the various systems used by Abrahamson et al. [2] to conclude that the per locus per rad (low LET) radiation-induced forward mutation rates in organisms, whose DNA content varies by a factor of about 1000, is proportional to genome size. Additional information pertinent in this context is also reviewed.