Using Trellis software to enhance high-quality large-scale network data collection in the field.

Trellis is a mobile platform created by the Human Nature Lab at the Yale Institute for Network Science to collect high-quality, location-aware, off-line/online, multi-lingual, multi-relational social network and behavior data in hard-to-reach communities. Respondents use Trellis to identify their social contacts by name and photograph, a procedure especially useful in low-literacy populations or in contexts where names may be similar or confusing. We use social network data collected from 1,969 adult respondents in two villages in Kenya to demonstrate Trellis' ability to provide unprecedented metadata to monitor and report on the data collection process including artifactual variability based on surveyors, time of day, or location.

Exploiting social influence to magnify population-level behaviour change in maternal and child health: study protocol for a randomised controlled trial of network targeting algorithms in rural Honduras.

INTRODUCTION: Despite global progress on many measures of child health, rates of neonatal mortality remain high in the developing world. Evidence suggests that substantial improvements can be achieved with simple, low-cost interventions within family and community settings, particularly those designed to change knowledge and behaviour at the community level. Using social network analysis to identify structurally influential community members and then targeting them for intervention shows promise for the implementation of sustainable community-wide behaviour change. METHODS AND ANALYSIS: We will use a detailed understanding of social network structure and function to identify novel ways of targeting influential individuals to foster cascades of behavioural change at a population level. Our work will involve experimental and observational analyses. We will map face-to-face social networks of 30 000 people in 176 villages in Western Honduras, and then conduct a randomised controlled trial of a friendship-based network-targeting algorithm with a set of well-established care interventions. We will also test whether the proportion of the population targeted affects the degree to which the intervention spreads throughout the network. We will test scalable methods of network targeting that would not, in the future, require the actual mapping of social networks but would still offer the prospect of rapidly identifying influential targets for public health interventions. ETHICS AND DISSEMINATION: The Yale IRB and the Honduran Ministry of Health approved all data collection procedures (Protocol number 1506016012) and all participants will provide informed consent before enrolment. We will publish our findings in peer-reviewed journals as well as engage non-governmental organisations and other actors through venues for exchanging practical methods for behavioural health interventions, such as global health conferences. We will also develop a 'toolkit' for practitioners to use in network-based intervention efforts, including public release of our network mapping software. TRIAL REGISTRATION NUMBER: NCT02694679; Pre-results.

THE POLYTYPIC SPECIES REVISITED: GENETIC DIFFERENTIATION AND MOLECULAR PHYLOGENETICS OF THE TIGER SALAMANDER AMBYSTOMA TIGRINUM (AMPHIBIA: CAUDATA) COMPLEX.

We present a phylogenetic analysis of the Ambystoma tigrinum complex, based on approximately 840 base pairs of mitochondrial-DNA sequence from the rapidly evolving D-loop and an adjacent intron. Our samples include populations of the continentally distributed species, A. tigrinum, plus all described species of Mexican ambystomatids. Sequence divergence is low, ranging from 0-8.5%, and most phylogenetic groupings are weakly supported statistically. We identified eight reasonably well-defined clades from the United States and Mexico, with the geographically isolated A. californiense from California as the probable sister group to the remaining taxa. Our sequence data are not capable of resolving the relationships among these clades, although the pattern of transitional-site evolution suggests that these eight lineages diverged during a period of rapid cladogenesis. We roughly calibrate a molecular clock and identify a few lineages that significantly deviate from the slow, baseline rate of 0.5-0.75% per million years. Our data also suggest that species boundaries for several U.S. and Mexican species need to be altered and that the concept of a continentally distributed, polytypic tiger salamander is not valid.

MITOCHONDRIAL DNA PHYLOGEOGRAPHY OF PEROGNATHUS AMPLUS AND PEROGNATHUS LONGIMEMBRIS (RODENTIA: HETEROMYIDAE): A POSSIBLE MAMMALIAN RING SPECIES.

Substantiated cases of ring species in mammals are rare. I examined the variation in mitochondrial DNA (mtDNA) of Perognathus amplus and P. longimembris in and around Arizona to test the hypothesis proposed by Hoffmeister (1986) that these two taxa are members of a single ring species demonstrating circular overlap. Through digestion of purified mtDNA from 45 P. amplus and 35 P. longimembris with 16 type II restriction enzymes, I identified 38 distinct haplotypes that belong to eight different evolutionary lineages. I then amplified and directly sequenced a portion of the mitochondrial cytochrome-b region from individuals representative of the lineages identified by restriction fragments, and used these data for phylogeny reconstruction in both a parsimony and neighbor-joining setting. The resulting phylogeny was consistent with the ring hypothesis, but, based on the incompleteness of the ring of subspecies and the apparent timing of evolutionary events in this group, I conclude that P. amplus and P. longimembris are distinct lineages that have completed the speciation process.

THE EFFECTS OF KIN-STRUCTURED COLONIZATION ON NUCLEAR AND CYTOPLASMIC GENETIC DIVERSITY.

We investigate kin-structured migration and its effects on patterns of genetic variation in cytoplasmic and nuclear genomes. We show that colonization events involving close relatives, such as those that might characterize range expansion and the invasion of new habitats, can change the patterns of nuclear and cytoplasmic genetic variation expected at equilibrium. The difference in the patterns of variation between the nuclear and mitochondrial genomes suggests that it may be possible to estimate the time of the effective kin-structured colonization event. Observations in several taxa are discussed in light of these findings and in relation to their known geological history.