Global Population Genomics of the Endangered Great Hammerhead Shark, Sphyrna mokarran

The great hammerhead shark, Sphyrna mokarran, is a circumglobal coastal-pelagic species of high conservation concern (IUCN Red List: Endangered). Our earlier analysis of mitochondrial control region sequences in globally distributed animals uncovered two highly genetically divergent matrilines in this species (Testerman et al. In prep.). Here we present findings of a genomic level assessment of global population dynamics of the great hammerhead shark based on analyses of nuclear single nucleotide polymorphisms (SNPs) and whole mitochondrial genome sequences (17,719 bp). Analysis of 2330 neutral SNP loci with Discriminant Analysis of Principal Components (DAPC) and the Bayesian clustering program STRUCTURE reveals three geographic meta-populations (Western Atlantic, North Indian Ocean, and Australia). Pairwise comparisons (FST, G’’ST, and Jost’s D) further reveals highly structured sub-populations within these regions including evidence of differentiation between Western Australia and Eastern Australia individuals, which was previously undetected. Analysis of molecular variance (AMOVA, FST) of whole mitochondrial genomes supports the three meta-populations, with a lesser degree but still significant level of sub-population structuring. A median joining haplotype network additionally supports the previously detected divergent matrilines, separated by an estimated 99 mutational steps. Preliminary demographic analyses support the hypothesis of an Indo-West Pacific origin followed by colonization of the Indian Ocean and subsequently the Atlantic

Patient delay in seeking care for heart attack symptoms: findings from focus groups conducted in five U.S. regions

BACKGROUND: Patient delay in seeking health care for heart attack symptoms is a continuuing problem in the United States. METHODS: Investigators conducted focus groups (N = 34; 207 participants) in major U.S. regions (NE, NW, SE, SW, MW) as formative evaluation to develop a multi-center randomized community trial (the REACT Project). Target groups included adults with previous heart attacks, those at higher risk for heart attack, and bystanders to heart attacks. There were also subgroups reflecting gender and ethnicity (African-American, Hispanic-American, White). FINDINGS: Patients, bystanders, and those at higher risk expected heart attack symptoms to present as often portrayed in the movies, that is, as sharp, crushing chest pain rather than the more common onset of initially ambiguous but gradually increasing discomfort. Patients and those at higher risk also unrealistically judge their personal risk as low, understand little about the benefits of rapid action, are generally unaware of the benefits of using EMS/9-1-1 over alternative transport, and appear to need the permission of health care providers or family to act. Moreover, participants reported rarely discussing heart attack symptoms and appropriate responses in advance with health care providers, spouses, or family members. Women often described heart attack as a male problem, an important aspect of their underestimation of personal risk. African-American participants were more likely to describe negative feelings about EMS/9-1-1, particularly whether they would be transported to their hospital of choice. CONCLUSIONS: Interventions to reduce patient delay need to address expectations about heart attack symptoms, educate about benefits and appropriate actions, and provide legitimacy for taking specific health care-seeking actions. In addition, strategy development must emphasize the role of health care providers in legitimizing the need and importance of taking rapid action in the first place