Parched elastohydrodynamic lubrication: Instrumentation and procedure

A counter rotating bearing rig was designed and constructed to study transient elastohydrodynamic lubrication phenomena. New instrumentation is described and test procedures are documented. Ball and race speed measurement systems and the capacitance (film thickness) measurement system were upgraded. Methods for measuring bearing torque and race temperatures were implemented

A Rapid Prototyping Environment for Wireless Communication Embedded Systems

This paper introduces a rapid prototyping methodology which overcomes important barriers in the design and implementation of digital signal processing (DSP) algorithms and systems on embedded hardware platforms, such as cellular phones. This paper describes rapid prototyping in terms of a simulation/prototype bridge and in terms of appropriate language design. The simulation/prototype bridge combines the strengths of simulation and of prototyping, allowing the designer to develop and evaluate next-generation communications systems, partly in simulation on a host computer and partly as a prototype on embedded hardware. Appropriate language design allows designers to express a communications system as a block diagram, in which each block represents an algorithm specified by a set of equations. Software tools developed for this paper implement both concepts, and have been successfully used in the development of a next-generation code division multiple access (CDMA) cellular wireless communications system.NokiaTexas InstrumentsThe Texas Advanced Technology ProgramNational Science Foundatio

Regrowth-related defect formation and evolution in 1 MeV amorphized (001) Ge

Geimplanted with 1MeV Si⁺ at a dose of 1×10¹⁵cm⁻² creates a buried amorphous layer that, upon regrowth, exhibits several forms of defects–end-of-range (EOR), regrowth-related, and clamshell defects. Unlike Si, no planar {311} defects are observed. The minimal EOR defects are small dotlike defects and are very unstable, dissolving between 450 and 550°C. This is in contrast to Si, where the EOR defects are very stable. The amorphous layer results in both regrowth-related defects and clamshell defects, which were more stable than the EOR damage.This work is supported by Semiconductor Research Corporation Contract No. 00057787

Gradually Then Suddenly? Decline in Vision-Related Quality of Life as Glaucoma Worsens

Purpose: To evaluate the relationship between self-reported vision-related quality of life (VRQL) and visual field (VF) loss in people from glaucoma clinics. Methods: A postal survey using the National Eye Institute Visual Function Questionnaire (NEI VFQ-25) was administered to people with a range of VF loss identified from a UK hospital-based glaucoma service database. Trends were assessed in a composite score from NEI VFQ-25 against better-eye mean deviation (BEMD) using linear regression and a spline-fitting method that can highlight where a monotonic relationship may have different stages. Results: A total of 636 patients (median [interquartile range] BEMD −2.1 [−5.2, −0.4] dB, median age 70 [60, 77] years) were analysed. Analysis of trends in the data revealed an average patient loses approximately 2 units (out of 100) on NEI VFQ-25 for every loss of 1 dB (BEMD) as VF defects first become bilateral, up to BEMD −5 dB. NEI VFQ-25 deterioration then appears to slow before a more rapid phase of change (4–5 units per 1 dB loss) after BEMD worsens beyond −15 dB. Conclusions: Relationship between decline in VRQL and VF worsening in glaucoma is unlikely to be linear; it more likely has different phases, and these should be further explored in longitudinal studies

Example of monitoring measurements in a virtual eye clinic using 'big data'

Aim: To assess the equivalence of measurement outcomes between patients attending a standard glaucoma care service, where patients see an ophthalmologist in a face-to-face setting, and a glaucoma monitoring service (GMS). Methods: The average mean deviation (MD) measurement on the visual field (VF) test for 250 patients attending a GMS were compared with a ‘big data’ repository of patients attending a standard glaucoma care service (reference database). In addition, the speed of VF progression between GMS patients and reference database patients was compared. Reference database patients were used to create expected outcomes that GMS patients could be compared with. For GMS patients falling outside of the expected limits, further analysis was carried out on the clinical management decisions for these patients. Results: The average MD of patients in the GMS ranged from +1.6dB to −18.9dB between two consecutive appointments at the clinic. In the first analysis, 12 (4.8%; 95% CI 2.5% to 8.2%) GMS patients scored outside the 90% expected values based on the reference database. In the second analysis, 1.9% (95% CI 0.4% to 5.4%) GMS patients had VF changes outside of the expected 90% limits. Conclusions: Using ‘big data’ collected in the standard glaucoma care service, we found that patients attending a GMS have equivalent outcomes on the VF test. Our findings provide support for the implementation of virtual healthcare delivery in the hospital eye service

Photoreceptor Outer Segment-like Structures in Long-Term 3D Retinas from Human Pluripotent Stem Cells.

The retinal degenerative diseases, which together constitute a leading cause of hereditary blindness worldwide, are largely untreatable. Development of reliable methods to culture complex retinal tissues from human pluripotent stem cells (hPSCs) could offer a means to study human retinal development, provide a platform to investigate the mechanisms of retinal degeneration and screen for neuroprotective compounds, and provide the basis for cell-based therapeutic strategies. In this study, we describe an in vitro method by which hPSCs can be differentiated into 3D retinas with at least some important features reminiscent of a mature retina, including exuberant outgrowth of outer segment-like structures and synaptic ribbons, photoreceptor neurotransmitter expression, and membrane conductances and synaptic vesicle release properties consistent with possible photoreceptor synaptic function. The advanced outer segment-like structures reported here support the notion that 3D retina cups could serve as a model for studying mature photoreceptor development and allow for more robust modeling of retinal degenerative disease in vitro

Magnetic field dependence of the internal quality factor and noise performance of lumped-element kinetic inductance detectors

We present a technique for increasing the internal quality factor of kinetic inductance detectors (KIDs) by nulling ambient magnetic fields with a properly applied magnetic field. The KIDs used in this study are made from thin-film aluminum, they are mounted inside a light-tight package made from bulk aluminum, and they are operated near $150 \, \mathrm{mK}$. Since the thin-film aluminum has a slightly elevated critical temperature ($T_\mathrm{c} = 1.4 \, \mathrm{K}$), it therefore transitions before the package ($T_\mathrm{c} = 1.2 \, \mathrm{K}$), which also serves as a magnetic shield. On cooldown, ambient magnetic fields as small as approximately $30 \, \mathrm{\mu T}$ can produce vortices in the thin-film aluminum as it transitions because the bulk aluminum package has not yet transitioned and therefore is not yet shielding. These vortices become trapped inside the aluminum package below $1.2 \, \mathrm{K}$ and ultimately produce low internal quality factors in the thin-film superconducting resonators. We show that by controlling the strength of the magnetic field present when the thin film transitions, we can control the internal quality factor of the resonators. We also compare the noise performance with and without vortices present, and find no evidence for excess noise beyond the increase in amplifier noise, which is expected with increasing loss.Comment: 5 pages, 4 figure

North American Hard Yellow Liver Disease: An Old Problem Readdressed

Hard yellow liver disease or fatty cirrhosis periodically affects cattle, sheep, goats, pronghorn antelope (Antilocapra americana) and whitetail deer (Odocoileus virginianus texanus) within several Texas counties in the United States. Clinically it presents as chronic liver disease with progressive hepatic necrosis and fibrosis, icterus and liver failure. The damaged livers are yellow and many have multiple firm, often gritty foci that are scattered throughout all lobes. Early investigations included feeding studies using potential toxic plants, climate and forage studies, infectious disease surveys and various mycotoxin studies and analyses. None have definitively reproduced the disease or identified the inciting cause. However, the problem continues and recent outbreaks have allowed the collection of additional frozen tissues, and numerous paraffin tissue blocks and slides for additional studies. The objectives for this work are to evaluate and compare the microscopic changes, special histochemical studies, microbial and fungal surveys and chemical assays for dehyro-pyrrolizidine alkaloid (DHPA) metabolites of these additional cases with historical reports. These bovine livers had a spectrum of lesions including lipid degeneration and necrosis, eosinophilic granulomatous hepatitis, focal follicular lymphoid proliferation and chronic fibrosing hepatitis with dystrophic mineralization. No pyrrolizidine alkaloid metabolites were detected in any of the livers and select special stains did not reveal any fungal, bacterial or parasitic etiologies. The lack of findings and mixed histologic presentation suggest that this syndrome is a collection of chronic diseases probably of various etiologies. Earlier animal surveillance work is needed in endemic areas to better understand the etiology and pathogenesis of this syndrome