The use of terrestrial laser scanning for measurements in shallow-water : correction of the 3D coordinates of the point cloud

Although acoustic measurements are a wide-spread technique in the field of bathymetry, most systems require a water depth of at least 2 m. Furthermore, mapping shallow-water depths with acoustic techniques is expensive and complicated. Over the last decades, the use of laser scanning for mapping riverbeds has increased. However, the level of accuracy and the point density which can be obtained by Airborne Laser Scanning (ALS), and Airborne Laser Bathymetry (ALB) in particular, are not as high as those of terrain measurements originating from ALS. Moreover, ALS and ALB are not yet suited for mapping shallow-water beds. Therefore, more recent research focuses on the use of Terrestrial Laser Scanning (TLS) from either a fixed or static position (STLS) or from a mobile platform (MTLS). An obvious advantage of using STLS and MTLS is that both the river beds and the river banks can be modelled by means of the same data acquisition system. This ensures a seamless integration of data sets describing both dry and wet surfaces, and thus of topography and bathymetry. However, although STLS and MTLS have the potential to produce high resolution point clouds of shallow-water riverbeds and - banks, the resulting point clouds have to be corrected for the systematic errors in depth and distance that are caused by the refraction of the laser beam at its transition through the boundary of air and water. In this research a procedure was implemented to adjust the coordinates of every point situated beneath the water surface, based on the refractive index. The refractive index depends on the wavelength of the laser beam and the properties of the media the beam travels through. The refractive index for a laser beam with a wavelength of 532 nm varies by less than 1% for a wide range of temperature and salinity conditions. Nevertheless, during the case studies, it became clear that it is important to use an estimate of the refractive index which approaches the actual value as closely as possible in order to obtain accuracies of less than 1 to 2 cm. Therefore, the refractive index was determined for each specific case by using water samples

Immunofluorescent technique and long acting thyroid stimulator in human serum

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Grades of subclinical hypothyroidism in asymptomatic autoimmune thyroiditis revealed by the thyrotropin-releasing hormone test

Serum levels of T4, T3, and TSH and peak TSH after TRH administration were determined in 60 female subjects affected with asymptomatic autoimmune thyroiditis (AAT), in 27 normal subjects, and in 8 myxoedematous patients used as controls. The AAT subjects were divided into 3 groups on the basis of their basal and peak TSH values. In the first group (grade I AAT), these parameters were similar to those of the normal controls; in the second (grade II AAT), basal TSH remained normal but peak TSH was significantly increased; and in the third (grade III AAT), both parameters were significantly increased. Serum T4 levels decreased progressively from group 1 to group 3, but all T4 values were within the normal range. T3 levels were similar in all groups. Peak and basal TSH values were highly correlated, except in grade II AAT. There seems to exist a graded process of subclinical hypothyroidism in AAT; a progressive pituitary TSH reserve is modulated by a progressive decrease in T4 levels still within the normal range.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

TSH determination in rat serum by a homologous radioimmunoassay

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Asymptomatic atrophic thyroiditis

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Les anticorps bloquant la fonction thyroïdienne: nouveau concept d'autoimmunité thyroïdienne.

Journal ArticleResearch Support, Non-U.S. Gov'tReviewSCOPUS: re.jinfo:eu-repo/semantics/publishe

Pituitary TSH in normal subjects and in patients with asymptomatic atrophic thyroiditis: evidence for its immunological heterogeneity

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Natural history of primary myxedema

It is generally admitted that primary myxedema in adults is the outcome of autoimmune atrophic thyroiditis. The present review traces the natural history of this process from its incipient biologic and genetic anomalies up to its protracted asymptomatic course, clinical development, and eventual lethal complications. The apprehension of preclinical hypothyroidism may change a clinician's outlook on early diagnosis and therapy.SCOPUS: re.jinfo:eu-repo/semantics/publishe

Comparison between thyrotropin concentration and cell morphology of anterior pituitary in asymptomatic atrophic thyroiditis

TSH has been measured by bioassay in 22 pituitaries of patients with asymptomatic thyroiditis matched for age, sex and concomitant diseases with 18 pituitaries of control subjects. The mean TSH concentration was significantly increased in the thyroiditis pituitaries. Accordingly, the thyrotropes were increased in number and size, partially degranulated, with a dilated Golgi area and a large nucleolus. In a double-blind study performed on 8 cases, such morphologic evidence of thyrotropic activity was well correlated with a high TSH concentration. These observations provide evidence of hypertrophy of the thyrotropes along with increased TSH concentration in the hypophyses of asymptomatic thyroiditis cases. © 1972 by The Endocrine Society.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Thyroid auto-immune disease and thyroid function in families of subjects with down’s syndrome

In families of children affected with Down’s syndrome, the mothers show an increased frequency of clinical thyroid disorders; the fathers, the mothers, the siblings and the affected children present with a high incidence of thyroid autoantibodies and of an unusual pattern of the serum iodinated proteins. This is characterized by a normal PBI, a decreased BEI and a greatly increased butanol insoluble fraction (NBEI). The elevated serum NBEI level is probably a genetic trait. In the affected parents, it may correspond to an increased risk for chromosomal disturbances in the offspring. © 1970 by The Endocrine Society.SCOPUS: ar.jinfo:eu-repo/semantics/publishe