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The objective of this study was to systematically review all published articles examining the relationship between the occurrence of falls and changes in gait and attention-demanding task performance whilst dual tasking amongst older adults. An English and French Medline and Cochrane library search ranging from 1997 to 2008 indexed under ‘accidental falls’, ‘aged OR aged, 80 and over’, ‘dual task’, ‘dual tasking’, ‘gait’, ‘walking’, ‘fall’ and ‘falling’ was performed. Of 121 selected studies, fifteen met the selection criteria and were included in the final analysis. The fall rate ranged from 11.1% to 50.0% in retrospective studies and from 21.3% to 42.3% in prospective ones. Amongst the three retrospective and eight prospective studies, two and six studies, respectively, showed a significant relationship between changes in gait performance under dual task and history of falls. The predictive value for falling was particularly efficient amongst frail older adults compared with healthy subjects. Two prospective studies challenged the usefulness of the dual-task paradigm as a significant predictor compared to single task performance and three studies even reported that gait changes whilst dual tasking did not predict falls. The pooled odds ratio for falling was 5.3 (95% CI, 3.1–9.1) when subjects had changes in gait or attention-demanding task performance whilst dual tasking. Despite conflicting early reports, changes in performance whilst dual tasking were significantly associated with an increased risk for falling amongst older adults and frail older adults in particular. Description of health status, standardization of test methodology, increase of sample size and longer follow-up intervals will certainly improve the predictive value of dual-task-based fall risk assessment tests. [ABSTRACT FROM AUTHOR]

OBJECTIVES: To determine whether dual task-related changes in walking speed were associated with recurrent falls in frail older adults. DESIGN: Twelve-month prospective cohort study. SETTING: Thirteen senior housing facilities. PARTICIPANTS: Two hundred thirteen subjects (mean age 84.4+/-5.5). MEASUREMENTS: Usual and dual-tasking walking speeds (m/s) were calculated on a 10-m straight walkway at baseline. Information on incident falls during the follow-up year was collected monthly, and participants were divided into three groups based on the occurrence of falls (0, 1, and >or=2). Recurrent falls were defined as two or more falls during the 12-month follow-up period. RESULTS: Twenty subjects (9.4%) were classified as recurrent fallers. The occurrence of recurrent falls was associated with age (crude odds ratio (OR)=1.11, P=.02), number of drugs (crude OR=1.28, P=.002), and walking speed under both walking conditions (crude OR=0.96, P=.002 for usual walking and crude OR=0.60, P=.005 for walking while counting backward). Multiple Poisson regression showed that only walking speed while dual tasking and number of drugs were associated with incident falls (incident rate ratio (IRR)=0.84, P=.045 and IRR=1.10, P=.004). CONCLUSION: Slower walking speed while counting backward was associated with recurrent falls, suggesting that changes in gait performance while dual tasking might be an inexpensive way of identifying frail older adults prone to falling. [ABSTRACT FROM AUTHOR]

Bond valence analysis has been applied to various copper chalcogenides with copper valence excess, i.e. where the formal valence of copper exceeds 1. This approach always reveals a copper bond valence excess relative to the unit value, correlated to an equivalent ligand bond valence deficit. In stoichiometric chalcogenides, this corresponds to one ligand electron in excess per formula unit relative to the valence equilibrium considering only Cu I . This ligand electron in excess is 50/50 shared between all or part of the Cu-atom positions, and all or part of the ligand-atom positions. In Cu 3 Se 2 , only one of the two Cu positions is involved in this sharing. It would indicate a special type of multicentre bonding (`one-electron co-operative bonding'). Calculated and ideal structural formulae according to this bond valence distribution are presented. At the crystal structure scale, Cu-ligand bonds implying the single electron in excess form one-, two- or three-dimensional subnetworks. Bond valence distribution according to two two-dimensional subnets is detailed in covellite, CuS. This bond valence description is a formal crystal-chemical representation of the metallic conductivity of holes (mixing between Cu 3d bands and ligand p bands), according to published electronic band structures. Bond valence analysis is a useful and very simple prospective approach in the search for new compounds with targeted specific physical properties.

The beta-site amyloid precursor protein cleaving enzyme-1 (BACE-1) initiates the generation of amyloid-β (Aβ), and the amyloid cascade leading to amyloid plaque deposition, neurodegeneration, and dementia in Alzheimer's disease (AD). Clinical failures of anti-Aβ therapies in dementia stages suggest that treatment has to start in the early, asymptomatic disease states. The BACE-1 inhibitor CNP520 has a selectivity, pharmacodynamics, and distribution profile suitable for AD prevention studies. CNP520 reduced brain and cerebrospinal fluid (CSF) Aβ in rats and dogs, and Aβ plaque deposition in APP-transgenic mice. Animal toxicology studies of CNP520 demonstrated sufficient safety margins, with no signs of hair depigmentation, retina degeneration, liver toxicity, or cardiovascular effects. In healthy adults ≥ 60 years old, treatment with CNP520 was safe and well tolerated and resulted in robust and dose-dependent Aβ reduction in the cerebrospinal fluid. Thus, long-term, pivotal studies with CNP520 have been initiated in the Generation Program., (© 2018 Novartis AG. Published under the terms of the CC BY 4.0 license.)