We investigate loss mechanisms in 1.55m InGaAsP–InP multiquantum-well ridge-waveguide laser diodes at room temperature. The common method of measuring light versus current curves and plotting the inverse slope efficiency versus laser length is employed to extract the internal optical loss i and the differential internal efficiency i. This method neglects the dependence of both the parameters on...

Does the paucity of empirical evidence of sympatric speciation in nature reflect reality, despite theoretical support? Or is it due to inappropriate searches in nature with overly restrictive assumptions and an incorrect null hypothesis? Spiny mice, Acomys, described here at Evolution Canyon (EC) incipiently and sympatrically speciate owing to microclimatic interslope divergence. The opposite s...

We have determined the spectral dependence of the temporal point spread functions of human tissues experimentally between 740 and 840 nm in transmittance measurements on the adult head, forearm, and calf (in vivo) and the infant head (post mortem) by using picosecond laser pulses and a streak camera detector. Two parameters are extracted from the temporal point spread function; the differential...

Evidence is presented that recognition judgments are based on an assessment of familiarity, as is described by signal detection theory, but that a separate recollection process also contributes to performance. In 3 receiver-operating characteristics (ROC) experiments, the process dissociation procedure was used to examine the contribution of these processes to recognition memory. In Experiments...

Background. The interval from the R wave to the maximum amplitude of the T wave (RTm) contains the heart rate dependency of ventricular repolarization. Methods and Results. A computer algorithm was developed to quantify the RTm and preceding RR intervals for each of more than 50,000 beats on 24-hour ambulatory electrocardiographic (Holter) recordings to evaluate the dynamic relation between rep...

Although bilateral fimbria-fornix (FF) lesioning impairs spatial performance in animals, the literature is equivocal regarding its effects on hippocampal long-term potentiation (LTP). We examined the effects of FF lesioning on LTP induction in the Schaffer collateral-CA1 pathway in vivo with a protocol that delivered theta burst stimulation (TBS) trains of increasing length until a sufficient l...

We have measured the H I power spectrum of the nearly face-on spiral galaxy NGC 628 (M74) using a visibility-based estimator. The power spectrum is well fitted by a power law P(U) = AU , with α = −1.6 ± 0.2 over the length-scale 800 pc to 8 kpc. The slope is found to be independent of the width of the velocity channel. This value of the slope is a little more than one in excess of what has been...

Background: Left ventricular (LV) systolic function during atrial fibrillation (AF) is positively correlated with an index of ventricular cycle-length irregularity, the ratio of preceding R-R interval to pre-preceding R-R interval (RRp/RRpp). This study was designed to elucidate the relationship between the RRp/RRpp ratio and LV function, and to identify factors which influence the relationship...

The purpose of this study was to investigate the effects of transversely sloped ballasted walking surface on gait and rearfoot motion (RFM) parameters. Motion analysis was performed with 20 healthy participants (15 male and 5 female) walking in six surface-slope conditions: two surfaces (solid and ballasted) by three slopes (0, 5, and 10 degrees). The gait parameters (walking velocity, step len...

When statistical linkage to a certain chromosomal region has been found, it is of interest to develop methods quantifying the accuracy with which the disease locus can be mapped. In this paper, we investigate the performance of three different types of confidence regions, with asymptotically correct coverage probability as the number of pedigrees grows. Our setup is that of a saturated map of m...