Effects of marker type and filtering criteria on Q ST - F ST comparisons

Comparative studies of quantitative and neutral genetic differentiation ( Q ST - F ST tests) provide means to detect adaptive population differentiation. However, Q ST - F ST tests can be overly liberal if the markers used deflate F ST below its expectation, or overly conservative if methodological biases lead to inflated F ST estimates. We investigated how marker type and filtering criteria for marker selection influence Q ST - F ST comparisons through their effects on F ST using simulations and empirical data on over 18 000 in silico genotyped microsatellites and 3.8 million single-locus polymorphism (SNP) loci from four populations of nine-spined sticklebacks ( Pungitius pungitius ). Empirical and simulated data revealed that F ST decreased with increasing marker variability, and was generally higher with SNPs than with microsatellites. The estimated baseline F ST levels were also sensitive to filtering criteria for SNPs: both minor alleles and linkage disequilibrium (LD) pruning influenced F ST estimation, as did marker ascertainment. However, in the case of stickleback data used here where Q ST is high, the choice of marker type, their genomic location, ascertainment and filtering made little difference to outcomes of Q ST - F ST tests. Nevertheless, we recommend that Q ST - F ST tests using microsatellites should discard the most variable loci, and those using SNPs should pay attention to marker ascertainment and properly account for LD before filtering SNPs. This may be especially important when level of quantitative trait differentiation is low and levels of neutral differentiation high.

A signal-on photoelectrochemical biosensor for detecting cancer marker type IV collagenase by coupling enzyme cleavage with exciton energy transfer biosensing

A signal-on photoelectrochemical biosensor was developed for the sensitive detection of a cancer marker type IV collagenase, which relied on the exciton energy transfer between CdTe QDs and Ag NPs combined with the catalytic hydrolysis of protease.

Unwanted detachment of the Solitaire device during mechanical thrombectomy in acute ischemic stroke

BackgroundThe use of retrievable stents for endovascular clot retrieval has dramatically improved successful revascularization and clinical outcome in selected patients with acute stroke.ObjectiveTo describe the rate and clinical consequences of unwanted spontaneous detachment of these devices during mechanical thrombectomy.MethodsWe studied 262 consecutive patients treated with the retrievable stent, Solitaire, for acute ischemic stroke between November 2008 and April 2015. Clinical, procedural, and outcome variables were compared between patients with and without unexpected detachment of this device. Detachment was classified as proximal to the stent proximal marker (type A) or distal to the marker (type B). Poor functional outcome was defined as modified Rankin scale score >2 at 90 days.ResultsUnwanted detachment occurred in 6/262 (2.3%) cases, four of type A and two of type B. Stent recovery was possible in three patients, all of ‘type A’, but in none of ‘type B’. The number of prior passes was higher in patients with undesired detachment (3 (2–5) vs 2 (1–3), p=0.007). Detachment was associated with higher rate of symptomatic intracranial hemorrhage (SICH) (33.3% vs 4.3%, p=0.001), poorer outcome (100% vs 54.8%, p=0.028), and higher mortality rate at 90 days (50% vs 17%, p=0.038).ConclusionsUnwanted detachment of a Solitaire is an uncommon complication during mechanical thrombectomy in patients with acute ischemic stroke and is associated with the clot retrieval attempts, SICH, poor outcome, and higher mortality.