Imaging of ocean waves by synthetic aperture radar: a comparison ofresults from Seasat and SIR-B experiments in the North Atlantic

New analyses of wave spectra extracted from Seasat SAR images of the JASIN site in the northeast Atlantic are presented as tests of wave-imaging theory. Spectra extracted from orbit 757 during a high sea state are dominated by the effects of smearing, but the rms image smear is less than half that expected from in situ measurements of surface motions. In a low sea state on orbit 547 fair agreement can be achieved between SAR and buoy spectra, but this requires that the smearing length be greater than was observed on orbit 757. These findings are compared with results obtained from the Shuttle Imaging Radar SIR-B mission in order to assess the quantitative understanding of wave imaging by SAR     

Early hormonal and surgical treatment of cryptorchidism

PURPOSE: We investigated the efficacy of early gonadotropin treatment of cryptorchidism for promoting testicular descent and ameliorating testicular histology. MATERIALS AND METHODS: We treated 319 cryptorchid testes in 281 boys 4 months to 3 years old with luteinizing hormone-releasing hormone and human chorionic gonadotropin sequential therapy. Surgery was done on the 207 testes that did not respond to medical treatment. Microscopic biopsies were performed in 134 of these 207 testes. Histological findings were compared to those of 30 cryptorchid testes in boys younger than 1 year who underwent surgery without previous hormonal treatment. RESULTS: Combined luteinizing hormone-releasing hormone and human chorionic gonadotropin treatment induced scrotal descent of a percentage of cryptorchid testes depending on clinical position. Therapeutic success was greater when testes were in a lower position and results were not age dependent. Hormonal treatment of cryptorchidism during the first year of life stimulated spermatogonia maturation. CONCLUSIONS: When administered at the end of age 6 months, hormonal treatment can be considered an effective and timely substitution for gonadotropin and testosterone insufficiency in cryptorchid infants. Therefore, we recommend this therapeutic procedure combined with surgery in the first year of life.     

Contribution of job control and other risk factors to social variations in coronary heart disease incidence

BACKGROUND: The first Whitehall Study showed an inverse social gradient in mortality from coronary heart disease (CHD) among British civil servants--namely, that there were higher rates in men of lower employment grade. About a quarter of this gradient could be attributed to coronary risk factors. We analysed 5-year CHD incidence rates from the Whitehall II study to assess the contribution to the social gradient of psychosocial work environment, social support, coronary risk factors, and physical height. METHODS: Data were collected in the first three phases of examination of men and women in the Whitehall II study. 7372 people were contacted on all three occasions. Mean length of follow-up was 5.3 years. Characteristics from the baseline, phase 1, questionnaire, and examination were related to newly reported CHD in people without CHD at baseline. Three self-reported CHD outcomes were examined: angina and chest pain from the Rose questionnaire, and doctor-diagnosed ischaemia. The contribution of different factors to the socioeconomic differences in incident CHD was assessed by adjustment of odds ratios. FINDINGS: Compared with men in the highest grade (administrators), men in the lowest grade (clerical and office-support staff) had an age-adjusted odds ratio of developing any new CHD of 1.50. The largest difference was for doctor-diagnosed ischaemia (odds ratio for the lowest compared with the highest grade 2.27). For women, the odds ratio in the lowest grade was 1.47 for any CHD. Of factors examined, the largest contribution to the socioeconomic gradient in CHD frequency was from low control at work. Height and standard coronary risk factors made smaller contributions. Adjustment for all these factors reduced the odds ratios for newly reported CHD in the lowest grade from 1.5 to 0.95 in men, and from 1.47 to 1.07 in women. INTERPRETATION: Much of the inverse social gradient in CHD incidence can be attributed to differences in psychosocial work environment. Additional contributions were made by coronary risk factors--mainly smoking--and from factors that act early in life, as represented by physical height.     

Histamine release from rat mast cells induced by the metabolic activation of drugs of abuse into free radicals

Techniques such as positron-emission tomography, single-photon-emission computed tomography, functional magnetic-resonance imaging and magnetoencephalography permit the observation of biological processes in the brain in a noninvasive manner. They have yielded new insights into the biological interrelations of sensory, motor and cognitive functions, as well as into brain diseases. Combined use of these techniques may provide more information than just the sum of its constituents, and this may narrow the gap between the biological data provided by these techniques and the mental models described by clinicians, mathematicians, psychologists and philosophers.