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D C Wilson

Publications and source records attributed to D C Wilson.

At least 109 records · Page 6Linked to original sources
PubMed1974

Dynamic optometer.

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Accommodation, Ocular↗
PubMed1973

The 1970 yellow fever epidemic in Okwoga District Benue Plateau State, Nigeria. 2. Immunity survey to determine geographic limits and origins of the epidemic.

Serological surveys undertaken to define the geographic limits of the 1970 rural yellow fever epidemic in Okwoga District, Nigeria, indicated that surrounding areas of Benue Plateau State and East Central State were not involved. However, the surveys uncovered a separate focus of unrecognized, recent epidemic yellow fever in Mbawsi, in southern East Central State. The highest proportions of yellow-fever-immune sera outside the Okwoga and Mbawsi foci were found in zones of Guinea savannah in the Benue River basin.

Adolescent↗
PubMed1973

The 1970 yellow fever epidemic in Okwoga District, Benue Plateau State, Nigeria. 3. Serological responses in persons with and without pre-existing heterologous group B immunity.

Serological studies of persons infected with yellow fever (YF) during the 1970 epidemic in Okwoga District, Nigeria, indicated that epidemic YF occurred despite a high prevalence of pre-existing group B arbovirus immunity, which increased with age. The viruses involved were primarily dengue, Zika, and Wesselsbron. Patterns of responses of haemagglutination-inhibiting, complement-fixing, and neutralizing antibodies in primary YF and in superinfections are defined in this paper.

Adolescent↗
PubMed1972

Clinical features of yellow fever cases at Vom Christian Hospital during the 1969 epidemic on the Jos Plateau, Nigeria.

Between 27 September and 27 December 1969, 103 patients diagnosed as having yellow fever were admitted to Vom Christian Hospital, near Jos, Nigeria. Headache and vomiting were the commonest presenting complaints, and 95% of the patients showed scleral icterus or bile pigments in the urine. Haemorrhage, signs of renal failure, and CNS involvement (agitation, seizures) were associated with a grave prognosis. The overall case-fatality ratio was 45.6%. The average duration of illness for fatal cases was 6.4 days and for non-fatal cases 17.8 days. Six illustrative case histories are presented.

Adolescent↗
PubMedDate not supplied

A method for evaluation of enhancement operations in two-dimensional echocardiographic images.

A means of estimating the degree of enhancement of structure and suppression of background noise in filtered two-dimensional echocardiographic images is described. The method is termed the peak-to-background ratio. To test the method, two-dimensional short-axis echocardiographic images were enhanced with Laplacian operations of increasing mask size. There was excellent correlation between the calculated peak-to-background ratio and the subjective opinion of trained echocardiographers. Furthermore, radial length measurements made from images that were thought to be optimally enhanced by the peak-to-background ratio calculation showed the lowest interobserver mean differences. We conclude that the peak-to-background ratio does reflect improvement in characteristics of the image that favor more precise measurement (amplification of peaks and suppression of background) and can be used to help guide a dynamic approach to image processing.

Analog-Digital Conversion↗
PubMedDate not supplied

Applications of cross-correlation techniques to the quantitation of wall motion in short-axis two-dimensional echocardiographic images.

Echocardiography is now a mainstay in the diagnosis of cardiovascular disease. Rapid methods for quantitation of the images would provide an effective tool for the diagnosis of change in left ventricular function. The purpose of this article is to show the feasibility of using the cross-correlation technique to quantify change in left ventricular function over time in two-dimensional short-axis echocardiographic images. Radial histograms of radial distance versus the number of probable specular targets are formed in eight sectors on each frame during the cardiac cycle. These histograms are then shifted to a position of best correlation. The number of radial bins through which the histograms at end systole are shifted to correlate with those of the frame at end diastole defines the regional motion. The methods are described and preliminary findings are presented.

Algorithms↗