Antitrust - Robinson-Patman Act - Section 2(f) Buyer Liability

The United States Supreme Court has held that, unless a seller can be found liable for granting illegal discriminatory prices, a buyer cannot be held liable for inducing or receiving such prices. Great Atlantic & Pacific Tea Co. v. Federal Trade Commission, 99 S. Ct. 925 (1979)

Lightweight, Efficient Power Converters for Advanced Turboelectric Aircraft Propulsion Systems

NASA is investigating advanced turboelectric aircraft propulsion systems that use superconducting motors to drive multiple distributed turbofans. Conventional electric motors are too large and heavy to be practical for this application; therefore, superconducting motors are required. In order to improve aircraft maneuverability, variable-speed power converters are required to throttle power to the turbofans. The low operating temperature and the need for lightweight components that place a minimum of additional heat load on the refrigeration system open the possibility of incorporating extremely efficient cryogenic power conversion technology. This Phase II project is developing critical components required to meet these goals

A collaborative care pathway for patients with suspected angle closure glaucoma spectrum disease

Background: Currently, no specific collaborative care pathway exists that distinguishes open angle glaucoma from narrow angle or angle closure disease. This study evaluates a newly developed referral and collaborative care pathway specifically for patients with angle closure spectrum disease. Methods: The medical records of consecutive patients referred to the Centre for Eye Health for glaucoma assessment were examined, six months before (Pre Suite) and after (Post Suite) the introduction of a novel referral pathway for anterior chamber angle assessment (Angle Suite). Patient demographic and clinical data, the referral letter and practitioner characteristics were extracted. Results: Angle Suite (n = 77) patients had an appointment much sooner compared to Pre (n = 383) and Post Suite (n = 425) patients (p < 0.0001). Following the introduction of Angle Suites, there was a reduction of incidental angle closure disease found in routine, non-angle closure glaucoma assessment. Onward referral was required by 36.4 per cent of patients referred for suspected angle closure disease, while the rest could be discharged back into the community (13.0 per cent) or reviewed at the Centre for Eye Health (50.6 per cent). Multinomial logistic regression found that the presence of an angle description in the referral letter improved the true positive rate for angle closure disease (p < 0.0001). Conclusions: The clinical pathway may reduce the number of incidental angle closure patients and improved the timeliness of appropriate clinical care delivered to a subset of patients who may benefit from prompt medical attention. This pathway provides an opportunity for appropriately staffed and equipped collaborative care clinics to reduce the burden on tertiary level ophthalmic facilities

Wavelength- and material-dependent absorption in GaAs and AlGaAs microcavities

The quality factors of modes in nearly identical GaAs and Al_{0.18}Ga_{0.82}As microdisks are tracked over three wavelength ranges centered at 980 nm, 1460 nm, and 1600 nm, with quality factors measured as high as 6.62x10^5 in the 1600-nm band. After accounting for surface scattering, the remaining loss is due to sub-bandgap absorption in the bulk and on the surfaces. We observe the absorption is, on average, 80 percent greater in AlGaAs than in GaAs and in both materials is 540 percent higher at 980 nm than at 1600nm.Comment: 4 pages, 2 figures, 1 table, minor changes to disucssion of Qrad and Urbach tai

Anterior Chamber Angle Evaluation Using Gonioscopy: Consistency and Agreement between Optometrists and Ophthalmologists

SIGNIFICANCE In our intermediate-tier glaucoma care clinic, we demonstrate fair to moderate agreement in gonioscopy examination between optometrists and ophthalmologists, but excellent agreement when considering open versus closed angles. We highlight the need for increased consistency in the evaluation and recording of angle status using gonioscopy. PURPOSE The consistency of gonioscopy results obtained by different clinicians is not known but is important in moving toward practice modalities such as telemedicine and collaborative care clinics. The purpose of this study was to evaluate the description and concordance of gonioscopy results among different practitioners. METHODS The medical records of 101 patients seen within a collaborative care glaucoma clinic who had undergone gonioscopic assessment by two clinicians (one optometrist and either one general ophthalmologist [n = 50] or one glaucoma specialist [n = 51]) were reviewed. The gonioscopy records were evaluated for their descriptions of deepest structure seen, trabecular pigmentation, iris configuration, and other features. These were compared between clinicians (optometrist vs. ophthalmologist) and against the final diagnosis. RESULTS Overall, 51.9 and 59.8% of angles were graded identically in terms of deepest visible structure when comparing between optometrist versus general ophthalmologist and optometrist versus glaucoma specialist, respectively. The concordance increased when considering ±1 of the grade (67.4 and 78.5%, respectively), and agreement with the final diagnosis was high (>90%). Variations in angle grading other than naming structures were observed (2.0, 30, and 3.9% for optometrist, general ophthalmologist, and glaucoma specialist, respectively). Most of the time, trabecular pigmentation or iris configuration was not described. CONCLUSIONS Fair to moderate concordance in gonioscopy was achieved between optometrists and ophthalmologists in a collaborative care clinic in which there is consistent feedback and clinical review. To move toward unified medical records and a telemedicine model, improved consistency of record keeping and angle description is required

A Guyon's canal ganglion presenting as occupational overuse syndrome: A case report

<p>Abstract</p> <p>Background</p> <p>Occupational overuse syndrome (OOS) can present as Guyon's canal syndrome in computer keyboard users. We report a case of Guyon's canal syndrome caused by a ganglion in a computer user that was misdiagnosed as OOS.</p> <p>Case presentation</p> <p>A 54-year-old female secretary was referred with a six-month history of right little finger weakness and difficulty with adduction. Prior to her referral, she was diagnosed by her general practitioner and physiotherapist with a right ulnar nerve neuropraxia at the level of the Guyon's canal. This was thought to be secondary to computer keyboard use and direct pressure exerted on a wrist support. There was obvious atrophy of the hypothenar eminence and the first dorsal interosseous muscle. Both Froment's and Wartenberg's signs were positive. A nerve conduction study revealed that both the abductor digiti minimi and the first dorsal interosseus muscles showed prolonged motor latency. Ulnar conduction across the right elbow was normal. Ulnar sensory amplitude across the right wrist to the fifth digit was reduced while the dorsal cutaneous nerve response was normal. Magnetic resonance imaging of the right wrist showed a ganglion in Guyon's canal. Decompression of the Guyon's canal was performed and histological examination confirmed a ganglion. The patient's symptoms and signs resolved completely at four-month follow-up.</p> <p>Conclusion</p> <p>Clinical history, occupational history and examination alone could potentially lead to misdiagnosis of OOS when a computer user presents with these symptoms and we recommend that nerve conduction or imaging studies be performed.</p

Sensor Integrated Metal Dielectric Filters for Solar-Blind Silicon Ultraviolet Detectors

A filter for electromagnetic radiation including one or more dielectric spacer regions and one or more reflective regions integrated on a semiconductor substrate, the semiconductor substrate including a semiconductor photodetector, such that the filter transmits ultraviolet radiation to the semiconductor photodetector, the ultraviolet radiation having a range of wavelengths, and the filter suppresses transmission of electromagnetic radiation, having wavelengths outside the range of wavelengths, to the semiconductor photodetector

The Angular Clustering of Galaxy Pairs

We identify close pairs of galaxies from 278 deg^2 of Sloan Digital Sky Survey commissioning imaging data. The pairs are drawn from a sample of 330,041 galaxies with 18 < r^* < 20. We determine the angular correlation function of galaxy pairs, and find it to be stronger than the correlation function of single galaxies by a factor of 2.9 +/- 0.4. The two correlation functions have the same logarithmic slope of 0.77. We invert Limber's equation to estimate the three-dimensional correlation functions; we find clustering lengths of r_0= 4.2 +/- 0.4 h^{-1} Mpc for galaxies and 7.8 +/- 0.7 h^{-1} Mpc for galaxy pairs. These results agree well with the global richness dependence of the correlation functions of galaxy systems.Comment: 12 pages. ApJ, in pres

Spectroscopy of Quasar Candidates from SDSS Commissioning Data

The Sloan Digital Sky Survey has obtained images in five broad-band colors for several hundred square degrees. We present color-color diagrams for stellar objects, and demonstrate that quasars are easily distinguished from stars by their distinctive colors. Follow-up spectroscopy in less than ten nights of telescope time has yielded 22 new quasars, 9 of them at $z> 3.65$, and one with $z = 4.75$, the second highest-redshift quasar yet known. Roughly 80% of the high-redshift quasar candidates selected by color indeed turn out to be high-redshift quasars.Comment: 4 pages, 3 figures, to appear in the proceedings of "After the Dark Ages: When Galaxies were Young (the Universe at 2<z<5)", 9th Annual October Astrophysics Conference in Marylan

Climate change and health effects in Northwest Alaska

This article provides examples of adverse health effects, including weather-related injury, food insecurity, mental health issues, and water infrastructure damage, and the responses to these effects that are currently being applied in two Northwest Alaska communities