Adiabatic mode multiplexer for evanescent-coupling-insensitive optical switching.

A novel adiabatic mode multiplexer enables a 2 x 2 optical switch whose operation does not depend on accumulated phase due to evanescent coupling between waveguides. The adiabatic mode multiplexer has a negligible insertion loss over C+L bands and modal cross talk better than -40 dB for any polarization state. Mode multiplexing is achieved by adiabatic transition from the fundamental mode of the single-mode waveguide to the higher mode of the multimode waveguide. Experimental measurement results for a device realized in silica-on-silicon technology are presented. By directly measuring the nonadiabatic transition probability, we show that the adiabatic mode multiplexer operates in the Landau-Zener regime.

Ribosomal crystallography: from poorly diffracting microcrystals to high-resolution structures.

The cellular organelles translating the genetic code into proteins, the ribosomes, are large, asymmetric, flexible, and unstable ribonucleoprotein assemblies, hence they are difficult to crystallize. Despite two decades of intensive effort and thorough searches for suitable sources, so far only three crystal types have yielded high-resolution structures: two large subunits (from an archaean and from a mesophilic eubacterium) and one thermophilic small subunit. These structures have added to our understanding of decoding, have revealed dynamic aspects of the biosynthetic process, and have indicated the strategies adopted by ribosomes for interacting between themselves as well as with inhibitors, factors and substrates.

The relations among body image, physical attractiveness, and body mass in adolescence.

Body dissatisfaction, a measure of body image, physical attractiveness, and body mass index were assessed in the same 115 participants at ages 13, 15, and 18 years. Sex differences in body dissatisfaction emerged between 13 and 15 years of age and were maintained at 18. Over adolescence, girls increased, while boys decreased, their body dissatisfaction. Body dissatisfaction was weakly related to others' ratings of the adolescents' physical attractiveness and their body mass index. The results support the idea that, overall, adolescents' body image has little to do with how others perceive them, but once developed remains constant through much of adolescence.

Quantitation and distribution of vitronectin in synovial fluid and tissue of patients with rheumatic disease.

OBJECTIVE: Our study was undertaken to determine the quantity and pattern of distribution of vitronectin (Vn) in the synovial fluid and tissue of patients with rheumatic disease. METHODS: We quantitated synovial fluid Vn levels in 37 patients (17 with rheumatoid arthritis (RA), 12 with crystal induced arthritis (CIA), and 8 with osteoarthritis (OA)) using a competitive-binding ELISA: Immunofluorescence studies were performed on synovial pannus tissue specimens from 3 RA patients. SDS-PAGE analysis of the synovial fluids was performed to demonstrate the molecular forms of Vn present in inflammatory and noninflammatory synovial fluids. Albumin levels of synovial fluids were determined using an automated chemistry analyzer. RESULTS: Immunoreactive Vn was detected in 36 of 37 synovial fluid specimens examined, over a wide range of dilutions. Concentrations of Vn in inflammatory synovial fluid were significantly elevated compared to non-inflammatory synovial fluid and normal human plasma (NHP). Immunofluorescence studies revealed immunoreactive Vn most heavily concentrated in the lining layers of RA pannus tissue. Similar to NHP, molecular forms of Vn were heterogeneous in the synovial fluid; however, the inflammatory milieu appears to predispose Vn to cleavage at its protease-sensitive site. Overall there was a positive correlation of synovial fluid Vn to albumin. CIA and OA revealed a very strong relationship, whereas RA synovial fluid Vn levels correlated poorly to the levels of albumin. CONCLUSION: Vitronectin is present in synovial fluid. Levels are significantly enhanced in the inflamed joint and in the RA synovial lining, where it may influence cell adhesion and modulate tissue repair.

An evaluation of the balanced placebo design in alcohol administration research.

Results from a study using the balanced placebo design to assess alcohol's effects on anxiety raise serious doubts about the utility of the design even at moderate blood alcohol concentrations. Despite being informed that they were not drinking alcohol, 44% of the subjects who were administered alcohol reported consuming at least some alcohol. Moreover, subjects' scores on the Marlowe-Crowne Social Desirability Index (MCSD) were associated with deception success, suggesting that individual differences in reporting bias influence the manipulation. In contrast, only 6% of subjects who were told that they had consumed alcohol but were given tonic water were not deceived. Among subjects in this placebo condition, scores on the MCSD were not associated with success of the deception. These data suggest that at a moderate dose of alcohol, drink deception in the antiplacebo condition is much more difficult to execute than in the placebo condition, and that deception in the former condition may be confounded with experimenter demand.

Parental history of alcohol abuse and the effects of alcohol and expectations of intoxication on social stress.

Male and female social drinkers, half of whom had a biological father who abused alcohol, were exposed to a social stressor (anticipation and delivery of a public speech) after consuming either a moderate dose of alcohol or tonic water. Half of each group were led to believe that they had consumed alcohol, the other half tonic water, yielding a 2 x 2 x 2 x 2 factorial design. Intoxication, but not beliefs about having consumed alcohol, significantly reduced subjective anxiety and negative self-evaluation in response to the stressor in both men and women. Parental history of alcohol abuse differentially affected alcohol's influence on mood, but not measures of subjective intoxication, subjective physiological responses to alcohol, beliefs about alcohol's effects on behavior, or reactivity to the stressor.

Assessment of binge eating in obese patients.

Obese patients entering a weight control program were classified as binge eaters if they reported uncontrolled consumption of what others would regard as an unusually large amount of food at least once a week for the previous month. Binge eaters differed significantly from nonbingers across a broad range of eating and weight-related characteristics assessed using a self-report version of the Eating Disorder Examination. Attitudinal differences were marked. The results provided no support for the view that obese binge eaters have a pattern of general "addictiveness" to psychoactive substances or other activities.

Large basal cell carcinoma in a congenital nevus.

A large basal cell carcinoma that developed in a previously irradiated congenital nevus is reported. Treatment was by wide surgical excision. A discussion of the possibility that congenital nevi may predispose to tumors other than melanoma is considered. The causes of basal cell carcinoma are reviewed.

Nevus sebaceus, syringocystadenoma papilliferum, and basal cell epithelioma.

This case report illustrates the pluripotential nature of the hair matrix cells in nevus sebaceus. Syringocystadenoma papilliferum and basal cell epithelioma both developed in the same scalp lesion. The staged surgical excision is illustrated.

Cryotherapy of lentiginous mosaicism.

Liquid nitrogen cryospray treatments were successfully used to remove unilateral segmental lentigines. The rare disease of lentiginous mosaicism is described.

Computed tomography of diverticulitis.

Six cases of diverticulitis were studied by means of pelvic computed tomography (CT) and contrast enema. CT is effective in defining the intramural and extracolonic component of diverticulitis; abscess formation in the extracolonic space resulted in consistent changes in the contour of the opacified urinary bladder. Inflammatory extracolonic masses were imaged on CT as low or mixed-attenuation lesions frequently containing pockets of gas. Bladder wall thickening and edema, as well as contour asymmetry of the opacified and distended bladder, were reliable indicators of pericolonic or extracolonic extension of diverticular disease. Contrast enema and sigmoidoscopy are inherently limited in the evaluation of diverticulitis; CT of the pelvis reveals secondary changes outside the mucosa and bowel wall, CT directly images the inflammatory mass and associated changes in pelvic anatomic relationships. CT findings of pelvic inflammatory mass are not specific for abscess of diverticular origin; however, CT interpretation is reliable and confident since it is directed by the supporting findings on contrast enema. Integrated study by CT and contrast enema effectively defines the extent of disease in patients with diverticulitis. Summary evaluation of these studies has a serious impact on the choice of medical or surgical management.

Metastatic breast cancer in the eyelid.

Atypical cutaneous lesions in women following cancer of the breast should be biopsied to rule out the possibility of metastasis to distant cutaneous sites. An unusual location should not change the logical approach to diagnosis.

Idiopathic intrahepatic cholestasis of pregnancy. Report of an unusual case and review of the recent literature.

An atypical case of idiopathic cholestasis of pregnancy occurring in the 16th week of gestation in a 24-year old Pakistani female is presented. The case is unusual both in the duration of the jaundice as well as in the high levels of bilirubin found in the presence of normal renal function. A review of the recent literature emphasizes that this disorder is not entirely benign for the mother and the fetus. It also discusses some of the alterations in estrogen and lipid metabolism that are seen, as well as the possible mechanisms responsible for the increased incidence of gallstone formation found in these patients.

Concomitant erythrasma and dermatophytosis of the groin.

Four patients are reported with concomitant erythrasma and trichophyton rubrum dermatophytosis of the groin. The recognition and diagnosis of these associated infections is emphasized.