BACKGROUND The allergen dose-response curve is flat; thus, small changes in wheal size reflect large differences in skin sensitivity. The sensitivity as measured by provocation tests is given by the threshold concentration that causes symptoms and/or objective signs. The threshold concentrations differ by several magnitudes between the most and the least sensitive individuals clinically allergi...

BACKGROUND Metabolic syndrome in childhood predicts the development of cardiovascular disease and type 2 diabetes (T2D) in adulthood. Testing for features of metabolic syndrome, such as fasting plasma glucose concentration, requires blood sampling which can be difficult in children. Here we evaluated salivary glucose concentration as a surrogate measurement for plasma glucose concentration in 1...

2-D threshold function f is a function defined on the integer interior of a rectangular area [0, m] × [0, n] on a plane and takes values from the set {0, 1} such that there is a straight line separating the pre-images f −1 (0) and f −1 (1). For the number of such functions only asymptotic bounds were known. We give an exact formula for the number of 2-D threshold functions and derive an asympto...

The multiple-look notion holds that the difference limen (DL) decreases with multiple observations. We investigated this notion for temporal discrimination in isochronous sound sequences. In Experiment 1, we established a multiple-look effect when sequences comprised nine standard time intervals (S) followed by an increasing number of comparison time intervals (C), but no multiple-look effect w...

What is the spatial and temporal nature of odor representations within primary olfactory networks at the threshold of an animal's ability to discriminate? Although this question is of central importance to olfactory neuroscience, it can only be answered in model systems where neural representations can be measured and discrimination thresholds between odors can be characterized. Here, we establ...

BACKGROUND Short-term exposure to ozone has been associated with increased daily mortality. The shape of the concentration-response relationship-and, in particular, if there is a threshold-is critical for estimating public health impacts. OBJECTIVE We investigated the concentration-response relationship between daily ozone and mortality in five urban and five rural areas in the United Kingdom...

This novel, competitive immunoassay simultaneously detects seven drugs of abuse in urine. A urine sample is placed in contact with lyophilized reagents, the reaction mixture is allowed to come to equilibrium (10 min), and then the whole mixture is applied to a solid phase that contains various immobilized antibodies in discrete drug-class-specific zones. After a washing step, the operator visua...

Chemiluminescence has been used 10 study aerobic peroxidase-catalysed oxidation of indolyI-3-acetic acid (IAA). A threshold effect was found on inhibition of this reaction by its natural inhibitor caffeic acid. At an inhibitor concentration below threshold, only a temporary fall in the intensity of chemiluminescence and the reaction rale was established; at an above-threshold concentration, che...