The limiting distribution of the likelihood ratio statistic minus 21 n lambda sub n under a class of local alternatives, part 1. Minimum average risk decision procedures for the noncentral chi-square distribution, part 2

Limiting distribution of likelihood ratio statistic under class of local alternatives and minimum average risk decision procedures for noncentral chi-square distributio

Improvements in Blast Fragmentation Models Using Digital Image Processing

One of the fundamental requirements for being able to optimise blasting is the ability to predict fragmentation. An accurate blast fragmentation model allows a mine to adjust the fragmentation size for different downstream processes (mill processing versus leach, for instance), and to make real time adjustments in blasting parameters to account for changes in rock mass characteristics (hardness, fracture density, fracture orientation, etc). A number of blast fragmentation models have been developed in the past 40 years such as the Kuz-Ram model [1]. Fragmentation models have a limited usefulness at the present time because: 1. The input parameters are not the most useful for the engineer to determine and data for these parameters are not available throughout the rock mass. 2. Even if the input parameters are known, the models still do not consistently predict the correct fragmentation. This is because the models capture some but not all of the important rock and blast phenomena. 3. The models do not allow for ‘tuning’ at a specific mine site. This paper describes studies that are being conducted to improve blast fragmentation models. The Split image processing software is used for these studies

Developing interventions to address sexuality after stroke: Findings from a four-panel modified delphi study

© 2019 Foundation of Rehabilitation Information. Background: Although stroke has a profound impact on sexuality there are limited evidence-based interventions to support rehabilitation professionals in this area. The aim of the current research was to prioritize content areas and approaches to sexual rehabilitation from the perspective of stroke survivors, their partners, stroke rehabilitation clinicians and researchers. Methods: A 2-step online Delphi method was used to prioritize the content of, and approaches to, sexual rehabilitation with stroke survivors, their partners, stroke rehabilitation clinicians and researchers. Results: Stroke survivors (n=30), their partners (n=18), clinicians and researchers in stroke rehabilitation (n=45) completed at least 1 of 2 investigator-developed surveys. Participants prioritized 18 core content areas for inclusion in sexual rehabilitation following stroke with a high degree of consensus. Another 27 content areas were considered moderately important. There was strong consensus that sexual rehabilitation should be offered in the subacute and chronic phases of stroke recovery. Participants would prefer health professionals to deliver the intervention face-to-face. Conclusion: This study presents opinions from stroke survivors, partners of stroke survivors, clinicians and researchers. The information about content, timing and mode of delivery will be used to develop and evaluate a comprehensive sexuality rehabilitation programme

Si/SiGe bound-to-continuum quantum cascade emitters

Si/SiGe bound-to-continuum quantum cascade emitters designed by self-consistent 6-band k.p modeling and grown by low energy plasma enhanced chemical vapour deposition are presented demonstrating electroluminescence between 1.5 and 3 THz. The electroluminescence is Stark shifted by an electric field and demonstrates polarized emission consistent with the design. Transmission electron microscopy and x-ray diffraction are also presented to characterize the thick heterolayer structure

Effects of rapid thermal annealing on device characteristics of InGaAs/GaAs quantum dot infrared photodetectors

In this work, rapid thermal annealing was performed on InGaAs/GaAs quantum dot infrared photodetectors (QDIPs) at different temperatures. The photoluminescence showed a blueshifted spectrum in comparison with the as-grown sample when the annealing temperature was higher than 700 °C, as a result of thermal interdiffusion of the quantum dots (QDs). Correspondingly, the spectral response from the annealed QDIP exhibited a redshift. At the higher annealing temperature of 800 °C, in addition to the largely redshifted photoresponse peak of 7.4 µm (compared with the 6.1 µm of the as-grown QDIP), a high energy peak at 5.6 µm (220 meV) was also observed, leading to a broad spectrum linewidth of 40%. This is due to the large interdiffusion effect which could greatly vary the composition of the QDs and thus increase the relative optical absorption intensity at higher energy. The other important detector characteristics such as dark current, peak responsivity, and detectivity were also measured. It was found that the overall device performance was not affected by low annealing temperature, however, for high annealing temperature, some degradation in device detectivity (but not responsivity) was observed. This is a consequence of increased dark current due to defect formation and increased ground state energy. © 2006 American Institute of Physic

Designing and optimizing a micromanipulator-controlled surgical tool for reproducible nerve crush injuries in mice

Poster presented at the 2017 Health Sciences Research Day which was organized and sponsored by the University of Missouri School of Medicine Research Council and held on November 9, 2017.Introduction: Recurrent laryngeal nerve (RLN) injury, even if temporary, is a devastating complication of anterior cervical surgical procedures, resulting in debilitating dysphonia and dysphagia. During surgery, injury can be imparted by stretching, crushing, cauterizing, and/or transecting the laryngeal nerves. The injury can be temporary or permanent, depending on the severity and mechanism of insult. Treatment of the injury is generally palliative in nature and includes feeding tubes, voice and swallowing therapy, and diet modifications. The underlying pathophysiology of RLN is not completely understood. To effectively investigate various treatment strategies in mouse models, we need to improve the current translational animal model by standardizing the widely-used manual nerve crush techniques that apply variable force and may unintentionally add traction injuries. To control for these potential confounds, we are developing a micromanipulator-controlled surgical tool that (1) reliably applies a calibrated crush force injury, and (2) minimizes secondary injuries, such as traction, induced by manual methods

Ge-on-Si single-photon avalanche diode detectors: design, modeling, fabrication, and characterization at wavelengths 1310 and 1550 nm

The design, modeling, fabrication, and characterization of single-photon avalanche diode detectors with an epitaxial Ge absorption region grown directly on Si are presented. At 100 K, a single-photon detection efficiency of 4% at 1310 nm wavelength was measured with a dark count rate of ~ 6 megacounts/s, resulting in the lowest reported noise-equivalent power for a Ge-on-Si single-photon avalanche diode detector (1×10-14 WHz-1/2). The first report of 1550 nm wavelength detection efficiency measurements with such a device is presented. A jitter of 300 ps was measured, and preliminary tests on after-pulsing showed only a small increase (a factor of 2) in the normalized dark count rate when the gating frequency was increased from 1 kHz to 1 MHz. These initial results suggest that optimized devices integrated on Si substrates could potentially provide performance comparable to or better than that of many commercially available discrete technologies

Assessing Errors Inherent in OCT-Derived Macular Thickness Maps

SD-OCT has become an essential tool for evaluating macular pathology; however several aspects of data collection and analysis affect the accuracy of retinal thickness measurements. Here we evaluated sampling density, scan centering, and axial length compensation as factors affecting the accuracy of macular thickness maps. Forty-three patients with various retinal pathologies and 113 normal subjects were imaged using Cirrus HD-OCT. Reduced B-scan density was associated with increased interpolation error in ETDRS macular thickness plots. Correcting for individual differences in axial length revealed modest errors in retinal thickness maps, while more pronounced errors were observed when the ETDRS plot was not positioned at the center of the fovea (which can occur as a result of errant fixation). Cumulative error can exceed hundreds of microns, even under “ideal observer” conditions. This preventable error is particularly relevant when attempting to compare macular thickness maps to normative databases or measuring the area or volume of retinal features