Testing the cognitive effects of tadalafil. Neuropsychological secondary outcomes from the PASTIS trial.

Unlabelled: Cerebral small vessel disease (SVD) is a major cause of cognitive impairment in older people. As secondary endpoints in a phase-2 randomised clinical trial, we tested the effects of single administration of a widely-used PDE5 inhibitor, tadalafil, on cognitive performance in older people with SVD. In a double-blinded, placebo-controlled, cross-over trial, participants received tadalafil (20 mg) and placebo on two visits ≥ 7 days apart (randomised to order of treatment).

The PASTIS trial: Testing tadalafil for possible use in vascular cognitive impairment.

Introduction: There are few randomized clinical trials in vascular cognitive impairment (VCI). This trial tested the hypothesis that the PDE5 inhibitor tadalafil, a widely used vasodilator, increases cerebral blood flow (CBF) in older people with symptomatic small vessel disease, the main cause of VCI.

Methods: In a double-blind, placebo-controlled, cross-over trial, participants received tadalafil (20 mg) and placebo on two visits ≥7 days apart (randomized to order of treatment).

Test-retest reliability of arterial spin labelling for cerebral blood flow in older adults with small vessel disease.

Cerebral small vessel disease (SVD) is common in older people and is associated with lacunar stroke, white matter hyperintensities (WMH) and vascular cognitive impairment. Cerebral blood flow (CBF) is reduced in SVD, particularly within white matter.Here we quantified test-retest reliability in CBF measurements using pseudo-continuous arterial spin labelling (pCASL) in older adults with clinical and radiological evidence of SVD (N=54, mean (SD): 66.

A preliminary evaluation of ankle orthoses in the management of children with cerebral palsy.

The effectiveness of ankle-foot orthoses (AFOs) on walking pattern was studied in 12 children with cerebral palsy between the ages of 3 and 7 years. Over a 2-year period two trials of fortnightly periods without AFOs were carried out. The range of ankle dorsiflexion, video analysis looking specifically at footfall, and rank scoring of the mediolateral shear force obtained using an oscilloscope printout from a Kistler force platform were compared with measurements obtained during periods when the child was wearing AFOs.

Foraging rules for nectar: food choices by painted ladies.

Butterflies selected one of two contrasting locations for 10 visits without feeding followed by 16 visits with feeding. For each visit a location provided either 35% sucrose for 20 s versus 70% sucrose for 30 s or 35% sucrose for 20 s versus 70% sucrose for 20 s. These pairings tested between choices based on rates of net energy gain, net gains per visit, and/or net gains per meal.

Rates of energy processing by blowflies: the uses for a joule vary with food quality and quantity.

Data on the variation of crop volumes with time for blowflies (Phormia regina Meigen) fed various volumes and concentrations of fructose or sucrose (from Gelperin, 1966, and Edgecomb et al. 1987) were used to characterize energy processing rates to test the assumption of food energy addivity of optimal foraging theories. Six regression models (linear, square root, cube root, hyperbolic, inverse cube root and exponential) were compared for data from Edgecomb et al.

SEX CHANGE WITH INBREEDING: EXPERIMENTS ON SEPARATE VERSUS COMBINED SEXES.

Ipomopsis rubra plants grown in the laboratory initially produced hermaphrodite flowers, but some self- or sib-mated individuals switched to produce large numbers of pistillate (male sterile) flowers. The sex change did not occur with outcrossing. Plants with extreme male sterility were also observed in natural populations, usually in smaller individuals.

Floral arrangements and hummingbird feeding.

The influence of simulated inflorescence design on feeding behavior of 3 male Eugenes fulgens (Rivoli's hummingbird) and one female Lampornis clemenciae (Bluethroated hummingbird) was studied in the laboratory using artificial flowers. Five two-dimensional and three three-dimensional arrangements provided constant rewards per artificial flower. Visits to two-dimensional arrangements had more flower visits per feeding bout, proportionally more flower revisits, and shorter time between flowers than visits to three-dimensional arrangements.

Spatial learning as an adaptation in hummingbirds.

An ecological approach based on food distribution suggests that humming birds should more easily learn to visit a flower in a new location than to learn to return to a flower in a position just visited, for a food reward. Experimental results support this hypothesis as well as the general view that differences in learning within and among species represent adaptations.

Benzoyl peroxide assay using high-pressure liquid chromatography.

A highly specific assay for benzoyl peroxide was developed using high-pressure liquid chromatography. A concentration curve was recorded from 0.1 to 3.

Energetics of foraging: rate and efficiency of nectar extraction by hummingbirds.

The efficiency with which several species of hummingbirds extract nectar was estimated by converting the rate of extraction of nectar volumes to the energy expended and the energy obtained from the nectar. The extraction rates depend on corolla and bill morphologies, and the extraction efficiencies depend, in addition, on the bird weight and nectar concentration. Differential extraction efficiencies can be exploited by plants to increase pollinator specificity.

Regulation of oxygen consumption and body temperature during torpor in a hummingbird, Eulampis jugularis.

The West Indian hummingbird, Eulampis jugularis, maintained its body temperature in torpor at 18 degrees to 20 degrees C over an ambient temperature range of 2.5 degrees to 18 degrees C. At ambient below 18 degrees C oxygen consumption during torpor increased linearly with decreasing temperature.