Medieval DNA from Soqotra points to Eurasian origins of an isolated population at the crossroads of Africa and Arabia.

Soqotra, an island situated at the mouth of the Gulf of Aden in the northwest Indian Ocean between Africa and Arabia, is home to ~60,000 people subsisting through fishing and semi-nomadic pastoralism who speak a Modern South Arabian language. Most of what is known about Soqotri history derives from writings of foreign travellers who provided little detail about local people, and the geographic origins and genetic affinities of early Soqotri people has not yet been investigated directly. Here we report genome-wide data from 39 individuals who lived between ~650 and 1750 CE at six locations across the island and document strong genetic connections between Soqotra and the similarly isolated Hadramawt region of coastal South Arabia that likely reflects a source for the peopling of Soqotra. Medieval Soqotri can be modelled as deriving ~86% of their ancestry from a population such as that found in the Hadramawt today, with the remaining ~14% best proxied by an Iranian-related source with up to 2% ancestry from the Indian sub-continent, possibly reflecting genetic exchanges that occurred along with archaeologically documented trade from these regions. In contrast to all other genotyped populations of the Arabian Peninsula, genome-level analysis of the medieval Soqotri is consistent with no sub-Saharan African admixture dating to the Holocene. The deep ancestry of people from medieval Soqotra and the Hadramawt is also unique in deriving less from early Holocene Levantine farmers and more from groups such as Late Pleistocene hunter-gatherers from the Levant (Natufians) than other mainland Arabians. This attests to migrations by early farmers having less impact in southernmost Arabia and Soqotra and provides compelling evidence that there has not been complete population replacement between the Pleistocene and Holocene throughout the Arabian Peninsula. Medieval Soqotra harboured a small population that showed qualitatively different marriage practices from modern Soqotri, with first-cousin unions occurring significantly less frequently than today.

Selective Transesterification to Control Copolymer Microstructure in the Ring-Opening Copolymerization of Lactide and ε-Caprolactone by Lanthanum Complexes.

A series of novel lanthanum amido complexes, supported by ligands designed around the salan framework (salan = N,N'-bis(o-hydroxy, m-di-tert-butylbenzyl)-1,2-diaminoethane) were synthesized and fully characterized in the solid and solution states. The ligands incorporate benzyl or 2-pyridyl substituents at each tertiary amine center. The complexes were investigated as catalysts in the ring-opening homopolymerization of lactide (LA) and ε-caprolactone (ε-CL) and copolymerization of equimolar amounts of LA and ε-CL at ambient temperature. Solvent (THF or toluene) and the number of 2-pyridyl groups in the complex were found to influence the reactivity of the catalysts in copolymerization reactions. In all cases, complete conversion of LA to PLA was observed. The use of THF, a coordinating solvent, suppressed ε-CL polymerization, while the presence of one or more 2-pyridyl groups promoted ε-CL polymerization. Each copolymer gave a monomodal trace in gel permeation chromatography-size-exclusion chromatography (GPC-SEC) experiments, indicative of copolymer formation over homopolymerization. Copolymer microstructure was found to be dependent on catalyst structure and reaction solvent, ranging from blocky to close to alternating. Experiments revealed rapid conversion of LA in the initial stages of the reaction, followed by incorporation of ε-CL into the copolymer by either transesterification or propagation reactions. Significantly, the mode of transesterification (TI or TII) that occurs is determined by the structure of the metal complex and the reaction solvent, leading to the possibility of controlling copolymer microstructure through catalyst design.

Impact of a computerized order set on adherence to Centers for Disease Control guidelines for the treatment of victims of sexual assault.

BACKGROUND: Care of the sexual assault patient in the Emergency Department can be challenging due to complex pharmacologic interventions, evidence-collection procedures, and concomitant injury. OBJECTIVE: We sought to determine the effect of a standard, computerized order set for the treatment of adult victims of sexual assault on compliance with current Centers for Disease Control and Prevention (CDC) guidelines for the treatment of this population. METHODS: This study utilized a pretest-post-test design to evaluate the implementation of a standardized order set that provided clinicians with treatment recommendations consistent with CDC guidelines. Comparison of the rate of compliance with CDC guidelines before (n = 322) and after (n = 131) implementation of the order set was the primary outcome. Additional analyses examined for differences in compliance based upon evaluation by a sexual assault nurse/forensic examiner (SANE/SAFE), sex, and race. RESULTS: Pre-intervention phase compliance was 14 of 322 cases (4.4%) and post-intervention compliance was 108 of 131 cases (82.4%). This difference was statistically significant, χ(2) = 291.635, df = 1, p < 0.001. Overall, compliance with CDC pharmacologic recommendations was achieved in 122 (26.9%) cases. Evaluation by a SANE/SAFE nurse conferred no statistically significant difference in compliance. No statistically significant differences were noted based upon sex or race. CONCLUSIONS: The implementation of a standard, computerized order set for the treatment of adult victims of sexual assault significantly improved medical provider compliance with CDC treatment guidelines. This research demonstrates that electronic order sets can promulgate evidence-based practices in clinical medicine.