Dark sectors 2016 Workshop: community report

This report, based on the Dark Sectors workshop at SLAC in April 2016, summarizes the scientific importance of searches for dark sector dark matter and forces at masses beneath the weak-scale, the status of this broad international field, the important milestones motivating future exploration, and promising experimental opportunities to reach these milestones over the next 5-10 years

The Effects of the Standard Rolling Walker and Two Posterior Rolling Walkers on Gait Variables of Normal Children

The purpose of this study was to determine the effects of the standard rolling walker (SRW) and two veresions of the posteriorly placed posterior rolling walker on gait variable of a sample of normal children. The two versions of the posterior rolling walker included the two-wheeled model (PRW2) and the four-wheeled model (PRW4). Nineteen children aged six to eight years old from two suburban first and second grade classrooms comprised the sample. The footprint method of analysis was used to record and measure the variables of velocity, cadence, step length, stride length, base of support, and toe angle. Each child was initially recorded while walking unassisted, and then with ths SRW, PRW2 and PRW4 presented in randomized order for a total of four trials per child. The mean values for each gait variable were obtained for each trial for each child. A Multiple Analysis of Variance with one repeated measure and Duncan Multiple Comparison Tests were used to analyze these data. Results indicated that use of a walker, regardless of model, changed normal (unassisted) gait in all variables measured except toe angle. Gait using the PRW4 most closely approximated unassisted gait. Results may have implications for clinicians both in setting the optimal level of function that might be expected from children using walkers and in choosing among walker models for their patients

Genome-wide association study of age-related macular degeneration identifies associated variants in the TNXB-FKBPL-NOTCH4 region of chromosome 6p21.3

Age-related macular degeneration (AMD) is a leading cause of visual loss in Western populations. Susceptibility is influenced by age, environmental and genetic factors. Known genetic risk loci do not account for all the heritability. We therefore carried out a genome-wide association study of AMD in the UK population with 893 cases of advanced AMD and 2199 controls. This showed an association with the well-established AMD risk loci ARMS2 (age-related maculopathy susceptibility 2)–HTRA1 (HtrA serine peptidase 1) (P =2.7 × 10(−72)), CFH (complement factor H) (P =2.3 × 10(−47)), C2 (complement component 2)–CFB (complement factor B) (P =5.2 × 10(−9)), C3 (complement component 3) (P =2.2 × 10(−3)) and CFI (P =3.6 × 10(−3)) and with more recently reported risk loci at VEGFA (P =1.2 × 10(−3)) and LIPC (hepatic lipase) (P =0.04). Using a replication sample of 1411 advanced AMD cases and 1431 examined controls, we confirmed a novel association between AMD and single-nucleotide polymorphisms on chromosome 6p21.3 at TNXB (tenascin XB)–FKBPL (FK506 binding protein like) [rs12153855/rs9391734; discovery P =4.3 × 10(−7), replication P =3.0 × 10(−4), combined P =1.3 × 10(−9), odds ratio (OR) = 1.4, 95% confidence interval (CI) = 1.3–1.6] and the neighbouring gene NOTCH4 (Notch 4) (rs2071277; discovery P =3.2 × 10(−8), replication P =3.8 × 10(−5), combined P =2.0 × 10(−11), OR = 1.3, 95% CI = 1.2–1.4). These associations remained significant in conditional analyses which included the adjacent C2–CFB locus. TNXB, FKBPL and NOTCH4 are all plausible AMD susceptibility genes, but further research will be needed to identify the causal variants and determine whether any of these genes are involved in the pathogenesis of AMD