Cueing and gait improvement among people with Parkinson's disease: a meta-analysis.

Objective: To compare the relative efficacy of visual versus auditory cueing on gait among individuals with Parkinson's disease (PD).

Data Sources: A systematic search was completed up to September 2011, using the following databases: EMBASE, Scopus, Medline, CINAHL, and PubMed.

Study Selection: Four authors searched the databases using the following terms: Parkinson's disease (including abbreviations), gait, cadence, step, pace, cueing, cues, and prompt.

Renal sexual segment of the Cottonmouth snake, Agkistrodon piscivorous (Reptilia, Squamata, Viperidae).

The seasonal variation of the renal sexual segment (RSS) of males of the Cottonmouth snake, Agkistrodon piscivorous, is described using light and electron microscopy. This study is the first to describe the ultrastructure of the RSS of a viper (Viperidae) and only the fourth on a snake. Renal sexual segments from males collected February to May and from August to November are similar in appearance.