Data-Driven Participant Recruitment: Findings from the Alzheimer's Disease Neuroimaging Initiative 3.

BACKGROUND: Effective and measurable participant recruitment methods are urgently needed for clinical studies in Alzheimer's disease. OBJECTIVES: To develop methods for measuring recruitment tactics and evaluating effectiveness. METHODS: Recruitment tactics for the Alzheimer's Disease Neuroimaging Initiative (ADNI3) were measured using web and phone analytics, campaign metrics and survey responses. RESULTS: A total of 462 new participants were enrolled into ADNI3 through recruitment efforts. We collected metrics on recruitment activities including 82,003 unique visitors to the recruitment website and 3,335 calls to study phone numbers. The recruitment sources that produced the most screening and enrollment included online advertisements, local radio and newspaper coverage and emails and referrals from registries. CONCLUSIONS: Analysis of recruitment activity obtained through tracking methods provided some insight for effective recruitment. ADNI3 can serve as an example of how a data-driven approach to centralized participant recruitment can be utilized to facilitate clinical research.

mtDNA haplotypes differ in their probability of being eliminated by a mass die-off in an abundant seabird.

In this study, we take advantage of a natural experiment--a 2004 mass die-off of the Common Murre in Alaska to determine whether closely related mtDNA haplotypes differ in their probability of being eliminated during such a short term but a marked event removing hundreds of thousands of individuals. We sequenced complete mtDNA ND2 gene (1041 bp) for 168 Common Murres sampled from seven breeding colonies across Alaska before the 2004 die-off and 127 dead murres washed ashore during the die-off. We found little mtDNA variation and lack of geographical structuring among the seven Common Murre breeding colonies in Alaska. A comparison of the single-dominant mtDNA haplotype's frequency between live murres sampled on breeding colonies before the die-off (73.2%; 95% confidence interval 66.3-79.9%) and dead murres sampled during the die-off (59.1%; 95% confidence interval 50.4-67.4%; Fisher's exact P=0.01) showed that carriers of the dominant haplotype were significantly less likely to die than carriers of other haplotypes. At the same time, the ratio of non-synonymous to synonymous substitutions did not differ between live (10:35) and dead birds (18:34; Fisher's exact P=0.26), indicating that non-synonymous substitutions were as likely to be eliminated as synonymous substitutions. These results are consistent with the possibility of positive selection on the dominant mtDNA haplotype during the die-off.

Parallel evolution in the major haemoglobin genes of eight species of Andean waterfowl.

Theory predicts that parallel evolution should be common when the number of beneficial mutations is limited by selective constraints on protein structure. However, confirmation is scarce in natural populations. Here we studied the major haemoglobin genes of eight Andean duck lineages and compared them to 115 other waterfowl species, including the bar-headed goose (Anser indicus) and Abyssinian blue-winged goose (Cyanochen cyanopterus), two additional species living at high altitude. One to five amino acid replacements were significantly overrepresented or derived in each highland population, and parallel substitutions were more common than in simulated sequences evolved under a neutral model. Two substitutions evolved in parallel in the alpha A subunit of two (Ala-alpha 8) and five (Thr-alpha 77) taxa, and five identical beta A subunit substitutions were observed in two (Ser-beta 4, Glu-beta 94, Met-beta 133) or three (Ser-beta 13, Ser-beta 116) taxa. Substitutions at adjacent sites within the same functional protein region were also observed. Five such replacements were in exterior, solvent-accessible positions on the A helix and AB corner of the alpha A subunit. Five others were in close proximity to inositolpentaphosphate binding sites, and two pairs of independent replacements occurred at two different alpha(1)beta(1) intersubunit contacts. More than half of the substitutions in highland lineages resulted in the acquisition of serine or threonine (18 gains vs. 2 losses), both of which possess a hydroxyl group that can hydrogen bond to a variety of polar substrates. The patterns of parallel evolution observed in these waterfowl suggest that adaptation to high-altitude hypoxia has resulted from selection on unique but overlapping sets of one to five amino acid substitutions in each lineage.

Persistent MAPI scale 6 elevations after inpatient treatment.

Of 81 adolescent inpatients with elevated (> 74) admission scores on scale 6 (forceful/antisocial) of the Millon Adolescent Personality Inventory (MAPI; Millon, Green, & Meagher, 1982), 44 (54.32%) continued to have elevated scale 6 scores on the discharge administration of the test. These 44 subjects (labeled High 6) did not differ significantly from the other 37 subjects (labeled Low 6) on several variables that have been associated with conduct disturbance. The two groups did differ significantly, however, on family size, parental (especially paternal) psychopathology, and prognosis. The High 6 group tended to come from larger families, had a higher frequency of parental pathology, and more often received negative prognoses than did the Low 6 group. A discriminant function analysis conducted on the MAPI expressed concerns scales on the admission administration of the test resulted in a 76.54% correct classification of subjects into the High 6 and Low 6 groups. In general, the High 6 subjects appeared less troubled and more trouble than those subjects in the Low 6 group. The findings of this study demonstrate the potential of the MAPI as a component in the assessment of the treatment amenability of adolescents with disruptive behavior disorders.