Supervisory system for cascaded semiconductor laser amplifier repeaters

A technique for locating a transmission path failure in an inline cascade of semiconductor laser amplifier repeaters to within one fibre span is demonstrated. If a fault occurs, the loss of signal is detected in the following repeaters and a locally generated tone modulates the spontaneous emission of the repeater, signalling the fault to the system terminals.<>     

Semiconductor laser homodyne optical phase-locked-loop

A linear homodyne optical phase-locked-loop has been demonstrated using a semiconductor local oscillator laser and has been shown to exhibit good dynamic response to environmental influences. The receiver phase noise in this experiment was dominated by Rayleigh backscatter from the fibre link.     

OTDR in single-mode fibre at 1.5 ?m using heterodyne detection

Heterodyne detection has led to a significant improvement in the range performance of an optical time-domain reflectometer designed to operate on single-mode fibre at a wavelength of 1.52 ?m. With only 5 ?W peak launched power a range of 30 km was achieved.     

The psychological impact of AIDS on gay men.

Examines the psychological reactions of gay males who have been diagnosed as having acquired immune deficiency syndrome (AIDS), which may include fear of death and dying, guilt, fear of lifestyle exposure, fear of contagion, loss of self-esteem, fear of loss of physical attractiveness, fear of decreased social support, fear of increased isolation and stigmatization, loss of occupational and financial status, concerns and confusion over options for medical treatment, and the strong sense of gloom and helplessness associated with a degenerative illness. Many AIDS patients have reported that their psychological needs were not being adequately addressed. Programs designed to meet these needs, such as the special care ward for AIDS patients opened by San Francisco General Hospital, are described. Support groups have become an integral part of the mental health treatment of AIDS patients. Gay males who have symptoms described as "pre-AIDS," "lesser AIDS," or "prodromal AIDS" or who are asymptomatic have also begun to manifest acute psychological symptoms. Anxiety, uncertainty, isolation, and hypochondriasis are some of the reactions typically displayed by men in these groups. As a result of AIDS, psychotherapy with gay males in general has changed to some extent: Common topics now include grieving for friends' deaths from AIDS, feeling alone and helpless, and experiencing one's own mortality. Psychologists must adopt a delicate balance of remaining sex-positive and gay-affirmative while working toward an educational model of safe sex. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Polarisation guiding in ultralong distance soliton transmission

Signal polarisation rotation due to polarisation dependent loss has been observed for the first time in an optical communications transmission system. In particular its effect as a limiting factor in solitonic polarisation multiplexed systems is discussed. An analytic expression for the degree of rotation is presented and experimentally verified. Additionally, 5 Gbit/s solitons have been transmitted a distance of 11000 km without transmission control     

5 Gbit/s optical transmission system experiment employing laser amplifier repeater

The performance of a packaged semiconductor laser amplifier has been investigated for use in an optical transmission system at 5 Gbit/s. With optical filtering at the receiver input only small system penalties were found, as expected from the analysis of the dominant noise contributions.<>     

Biphasic aspects of homosexual identity formation.

Contends that during adolesence when homosexual self-labeling first occurs, the simultaneous awareness of homoerotic desires and the social odium associated with them tends to bring about conflict and a suppression of homosexual promptings among many homosexual males. The most common developmental consequence of this inhibition is a confounding of the process of identity formation. A biphasic pattern of identity development may occur so that during the 3rd decade or later unfinished psychological tasks of primary adolescence are resumed. It is suggested that the psychodynamics and phenomenology of this 2nd phase of identity formation bear a striking resemblance to those of primary psychological adolescence. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multichannel FSK experiment using an optical amplifier repeater and wavelength tunable direct detection receiver

A four channel direct detection FDM operating at 565 Mbit/s with a channel spacing of 12 GHz which achieves a receiver sensitivity of -40 dBm is reported. A laser preamplifier is used to overcome the optical processing loss of the channel selective filter.<>     

PSK homodyne receiver sensitivity measurements at 1.5 ?m

Measurements of the receiver sensitivity for an experimental optical PSK homodyne system, operating at 140 Mbit/s and at a wavelength of 1.52 ?m, have given a 19 dB sensitivity improvement over direct detection, and at ?64 dBm is approximately 2 dB away from the theoretically predicted value.     

Urinary flow rates in hypospadias

OBJECTIVES: To determine long-term results of patients who underwent primary ligament repair and delayed reconstruction for lateral ligament instability. DESIGN: Retrospective. SETTING: Outpatient clinic. PATIENTS/PARTICIPANTS: Patients who had undergone acute repair or delayed reconstruction at this institution between 1958 and 1977, excluding patients who were deceased or who could not be located. INTERVENTION: Forty-eight patients (fifty-three ankles) underwent twenty-two primary ligament repairs and thirty-one delayed reconstruction operations. MAIN OUTCOME MEASUREMENTS: Clinical results graded with clinical scale and radiologic results based on stress radiographs and plain film radiographs. RESULTS: At an average of twenty years after operation (range 12 to 33 years), patients were satisfied with forty-nine ankles, satisfied with reservations with two ankles, and dissatisfied with two ankles. Clinical results after repair were excellent in twenty ankles, good in one, fair in none, and poor in one. After reconstruction, the results were excellent in twenty-one ankles, good in six, fair in one, and poor in three. In the primary repair group, the mean talar tilt with stress testing improved from 20.7 +/- 10.7 degrees before operation to 2.8 +/- 3.0 degrees after operation. In the reconstruction group, the mean talar tilt improved from 20.7 +/- 8.4 degrees before operation to 2.8 +/- 3.5 degrees after operation. CONCLUSIONS: Clinical and radiologic results were similar in the repair and reconstruction groups. The majority of severe (Grade III) ankle sprains may be treated nonoperatively, but if residual instability occurs, late reconstruction should achieve satisfactory results.