Multigigabit transmission through rain in a dual polarizationfrequency reuse system: an experimental study

An experimental terrestrial link was set up for the purpose of evaluating very-high-data-rate communications in dual-polarization frequency reuse systems. Possible applications are in the field of satellite communications. Two 3.2-Gb/s signals using staggered quadriphase shift keying (SQPSK) were transmitted on opposite senses of circular polarization over a 7-km path located in Crane rain region D3. Performance degradation of the demodulator as a function of cross-polarization discrimination (XPD) was evaluated and found to closely match simulation predictions. However, the relationship between XPD and rain attenuation was found to be more complex than thought previously, displaying a relatively slowly varying hysteresis effect as well as significant interactions with characteristics of the receive antenna. The latter effect suggests that careful control of antenna characteristics may be required if such high-data-rate techniques are to be employed in space-ground links     

A method of dynamic foot-pressure measurement for the evaluation of pediatric orthopaedic foot deformities

We analysed 42 differentiated thyroid tumors including 15 follicular adenomas (FA), 13 papillary thyroid cancers (PTC) and 14 follicular thyroid carcinomas (FTC) with 13 microsatellite markers specific for the long arm of human chromosome 7 within 7q31; this region is deleted frequently in several other tumor types. Overall, 20 of the 42 samples analysed (48%) displayed LOH with one or more of the markers tested. LOH was detected most frequently (78%) in FTC, the most malignant of the thyroid tumors. A smallest common deleted region (SCDR) was defined in this tumor type flanked by markers D7S480 and D7S490. This SCDR is distinct from D7S522, the most commonly deleted locus in many other tumors, which was deleted in only one FTC. D7S522 did show LOH in two of six informative PTCs. None of the PTC and only two of the FAs showed LOH in the FTC SCDR. Since FA is considered a premalignant stage of FTC, our results suggest that inactivation of a putative tumor suppressor at 7q31.2 may be acquired during adenoma to carcinoma progression. The absence of LOH at this locus amongst PTC suggests that inactivation of this tumor suppressor is specific for FTC. In conclusion, LOH at 7q31 is a frequent event in differentiated thyroid cancer, and we have defined a 2 cM SCDR specific for FTC.     

On the variability of cross-sectional dimensions and torsional properties of rectangular nickel-titanium arch wires

BACKGROUND: Alterations in mouth temperature may lead to changes in the force exerted by an activated superelastic wire. It has been assumed that variations in archwire stiffness associated with short-term cooling or heating are transient. This investigation studied the effect of short-term cooling or heating on the bending force exerted by nickel-titanium archwire. MATERIAL AND METHODS: Six rectangular superelastic wires and one conventional nickel-titanium wire were tested in bending at 37 degrees C. The test specimens were deflected 0.5 mm, and the bending force was measured continually. The activated specimens were subjected to cold (10 degrees C) or hot (80 degrees C) water under constant deflection, simulating an inserted archwire that is subjected to cold or hot drinks or food during a meal. RESULTS: The conventional nickel-titanium wire was marginally affected by brief cooling or heating. In contrast, some of the superelastic wires were strongly affected by short-time application of cold or hot water. Whereas the effect of brief heating disappeared quickly, some wires continued to exert sub-baseline bending forces (up to 32% less) after short-time application of cold water and showed little or no tendencies toward increase even after 30 minutes of postexposure restitution (up to 43% less). CONCLUSIONS: Short-term exposures to hot liquid increased the bending force exerted for a given deflection transiently. The effect of short-term exposures to cold liquid was not always transient; the bending force remained sub-baseline for a number of the thermosensitive wires tested for a prolonged time.     

Regulation of the Na+/K(+)-ATPase pump in vitro after long-term exposure to cocaine: role of serotonin

Long-term exposure to cocaine can cause persistent behavioral changes and alterations in neuronal function. One cocaine-regulated mRNA in the rat brain is the beta-1 subunit of the Na+/K(+)-ATPase pump. We examined both Na+/K(+)-ATPase function and expression after cocaine treatment of pheochromocytoma cells. One-hour exposure to cocaine did not alter Na+/K(+)-ATPase activity, as measured by the ouabain-sensitive component of rubidium uptake. Four days of cocaine resulted in an approximately 30% decrease in Na+/K(+)-ATPase activity. Western blot analyses demonstrated an approximately 25% decrease in levels of the beta-1 isoform, without changes in pump total alpha subunit levels. Treatment with dopamine type 1 or type 2 receptor agonists for the same period did not affect Na+/K(+)-ATPase activity. The serotonin-selective reuptake inhibitor paroxetine caused an approximately 45% decrease in rubidium uptake after 4 days, whereas pump function was not altered after treatment with either the dopamine-selective reuptake blocker nomifensine or the norepinephrine-selective reuptake blocker desipramine. Chronic treatment with both cocaine and LY 278,584, a serotonin type 3 receptor antagonist, did not replicate the cocaine-associated decrease in pump function. Long-term cocaine exposure regulates expression and function of the Na+/K(+)-ATPase pump in neuronal-like cells; this regulation is mediated in part via the serotonin type 3 receptor. Similar Na+/K(+)-ATPase pump regulation in vivo may selectively alter neuronal function in the mammalian brain.     

Discontinuation of maintenance therapy in patients with quiescent cytomegalovirus retinitis and elevated CD4+ counts

OBJECTIVE: To determine whether maintenance therapy can be discontinued safety in patients with quiescent cytomegalovirus retinitis (CMVR) and increased CD4+ counts after treatment with highly active antiretroviral therapy (HAART). DESIGN: A prospective observational case series. PARTICIPANTS: Eight human immunodeficiency virus (HIV)-positive patients with quiescent CMVR who were taking HAART and had CD4+ counts above 100 cells/microliter elected to discontinue anti-CMV maintenance treatment. INTERVENTION: Biweekly-to-monthly indirect ophthalmoscopy and fundus photographs, monthly-to-quarterly CD4+ counts, and quarterly HIV viral loads were ordered. MAIN OUTCOME MEASURES: Twelve previously affected eyes were examined for evidence of recurrent retinitis, which was defined as any retinal whitening, border opacification, or expansion of areas of retinal pigment epithelial (RPE) atrophy greater than 750 microns. Four previously unaffected fellow eyes were observed for new CMVR. RESULTS: There was no reactivation or progression of retinitis in any patient during the mean follow-up interval of 11.4 months (range, 3-16 months). No previously unaffected eye developed CMVR. CD4+ remained elevated in all patients (range, 70-725; mean, 255). The HIV viral load ranged from undetectable to 139,000 copies. CONCLUSION: Discontinuation of maintenance therapy may be considered in patients with HAART-induced elevated CD4+ counts above 100 cells/microliter, prolonged relapse-free intervals during the reconstitution period before CD4+ counts rise above 100 cells/microliter, and completely quiescent retinitis characterized by RPE scarring only. Reduced risks of drug toxicity and drug-resistant organisms are potential benefits. Close observation for evidence of recurrent retinitis is indicated.     

Retail yield and fabrication times for veal as influenced by purchasing options and merchandising styles

Twenty-nine selected styles of subprimals or sections of veal were obtained from a commercial facility to assist in the development of a support program for retailers. They were fabricated into bone-in or boneless retail cuts and associated components by trained meat cutters. Each style selected (n = 6) was used to generate mean retail yields and labor requirements, which were calculated from wholesale and retail weights and processing times. Means and standard errors for veal ribs consisting of five different styles (n = 30) concluded that style #2, 7-rib 4 (10 cm) x 4 (10 cm), had the lowest percentage of total retail yield (P < .05) owing to the greatest percentage of bone. Furthermore, rib style #2 required the longest total processing time (P < .05). Rib styles #3, 7-rib chop-ready, and #5, 6-rib chop ready, yielded the greatest percentage of total retail yield and also had the shortest total processing time (P < .05). Within veal loins, style #2, 4 (10 cm) x 4 (10 cm) loin kidney fat in, had the greatest percentage fat (P < .05). Loin styles #2 and #3, 4 (10 cm) x 4 (10 cm) loin special trimmed, generated more lean and fat trimmings and bone, resulting in lower percentage of total retail yields than loin style #1, 0 (0 cm) x 1 (2.5 cm) loin special trimmed (P < .05). Results indicated that bone-in subprimals and sections required more processing time if fabricated into a boneless end point. In addition, as the number of different retail cuts increased, processing times also increased.     

Articular cartilage volume in the knee: semiautomated determination from three-dimensional reformations of MR images

PURPOSE: To determine the accuracy of semiautomated quantification of articular cartilage volume from three-dimensional (3D) reformations of magnetic resonance (MR) images. MATERIALS AND METHODS: Sagittal, fat-suppressed, 3D, spoiled gradient-recalled-echo MR imaging of two bovine and two human cadaver knees was performed. Articular cartilage volume was calculated from 3D reformations of the MR images by using a semiautomated program written at the authors' institution. Calculated volumes were compared with directly measured volumes of the surgically removed articular cartilage. RESULTS: The percentage of error of the MR imaging-determined volumes was 6.53% +/- 4.75 (mean +/- standard deviation). A strong correlation between the two sets of observations was shown (r=.997). Linear regression showed the calculated volumes to be highly accurate (slope=1.002, P>.25). Repeated reformations yielded volumes that were reproducible (mean absolute error, 0.013 mL +/- 0.019) and not significantly different from the measured volume (P>.10). CONCLUSION: Semiautomated quantification of knee articular cartilage from MR images yields highly accurate cartilage volumes.     

Actual daily dietary intake of selenium in Belgium, using duplicate portion sampling

The dietary selenium (Se) intake in Belgium has been re-evaluated. Duplicate meal collection, wet acid destruction and flow injection hydride generation atomic absorption spectrometry were used as techniques. The daily intake ranged from 28.4 g (Liège, Walloon part of the country) to 61.1 g (Vilvoorde, central part of the country). Compared with intakes recently published for other countries, the actual Belgian value corresponds to intermediate ranges of Se intake.

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Die aktuelle tägliche Selen-Aufnahme durch die Nahrung in Belgien, bestimmt durch doppelte Probenahme

Zusammenfassung Die Selen-Aufnahme durch die Nahrung in Belgien wurde neu bestimmt. Als Technik diente die doppelte Probenahme von Mahlzeiten, deren nasser Aufschluß und die Fließ-Injektions AAS mit Hydridgeneration. Die tägliche Aufnahme schwankt zwischen 28,4 und 61, 1 g. Im Vergleich zu Daten, die neuerdings aus anderen Ländern publiziert wurden, liegen die derzeitigen Werte aus Belgien im Mittelbereich.

     

Spatial performance with perspective displays as a function of computer graphics eyepoint elevation and geometric field of view

The purpose of this study was to investigate the effect of varying the elevation of the computer graphics eyepoint and the geometric field of view on judgements of spatial information using a stereoscopic perspective display. Twelve subjects judged the elevation and azimuth angle separating two computer-generated objects viewed using an eyepoint elevation that ranged between -15 degrees and 45 degrees and a geometric field of view that ranged between 40 degrees and 80 degrees. The results of the study indicated that judgements of elevation were affected by the compression of the vertical axis resulting from the raised eyepoint elevation. Furthermore, azimuth judgements were influenced by both the eyepoint elevation and the geometric field of view. Implications of the results for the design of displays and for spatial performance using stereoscopic displays are discussed.