Pulse oximetry utilizes the technique of photoplethysmography to estimate arterial oxygen saturation (SpO(2)) values. During hypothermia, the amplitude of the photoplethysmograph (PPG) is compromised which can lead to inaccurate estimation of SpO(2). A new mutlimode PPG/pulse oximeter sensor was developed to investigate the behaviour of PPGs during conditions of induced hypothermia (hand immers...

Sleep deprivation is a common problem in modern society. Because sleep is a time for the body to regenerate vital parts, especially neurons, it has been the subject of scientific studies for the past 30 plus years. Unfortunately, with lack of sleep come many unwanted side effects, including impaired thinking, memory, and the depression of some vital signs. This experiment was designed to test t...

We review the theoretical and experimental status of intense laser alignment—a field at the interface between intense laser physics and chemical dynamics with potential applications ranging from high harmonic generation and nanoscale processing to stereodynamics and control of chemical reactions. After placing the intense laser approach in context with other alignment techniques, we proceed wit...

BACKGROUND Sound production and hearing sensitivity of ectothermic animals are affected by the ambient temperature. This is the first study investigating the influence of temperature on both sound production and on hearing abilities in a fish species, namely the neotropical Striped Raphael catfish Platydoras armatulus. METHODOLOGY/PRINCIPAL FINDINGS Doradid catfishes produce stridulation soun...

The temperature dependence of the optical dephasing mechanism in an organic polymer glass, polymethylmethacrylate ͑PMMA͒, was studied from 300 K to 30 K using the dye IR144 as a probe. Transient grating and three pulse photon echo measurements were made, and the three pulse photon echo peak shift ͑3PEPS͒ was recorded as a function of temperature. The peak shift data reveal time constants of ϳ6 fs a...

BACKGROUND It has been reported that one of the main mechanisms that induces the activation of the cochlea through infrared laser light is the photothermal effect. The temperature in the spiral ganglion cells increases as a result of photon absorption. However, heat conduction can induce an increase in the temperature within the cochlea and change the spatial selectivity of activation. METHOD...

Subjects with severe chronic spinal cord injury (SCI) are prone to hypothermia when they are exposed to relatively low environmental temperatures that are normally well tolerated by healthy individuals. This impaired thermoregulation is presumably due to disconnection of territories below the SCI from supraspinal thermoregulatory centers. However, it is not known how these territories respond t...

Ambient temperature is known to affect the emission spectrum of a light-emitting diode (LED). This study has investigated the effect of changes in ambient temperature on the emission spectra of two LED with peak emission wavelengths similar to those used in pulse oximetry. There was a 5.5-nm increase in the peak wavelength for a 660-nm LED, and a 7.8-nm increase in the peak wavelength for a 950...