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Biomedical subjects

D Bigelow

Publications and source records attributed to D Bigelow.

7 recordsLinked to original sources
PubMed2001

Direct-Sun column ozone retrieval by the ultraviolet multifilter rotating shadow-band radiometer and comparison with those from Brewer and Dobson spectrophotometers.

A methodology for direct-Sun ozone retrieval using the ultraviolet multifilter rotating shadow-band radiometer (UV-MFRSR) is presented. Total vertical column ozone was retrieved in three stations: Mauna Loa, Hawaii, in the U.S., and Regina, Saskatchewan, and Toronto, Ontario, in Canada, from direct solar irradiances of the UV-MFRSR at 325-, 305-, 332-, and 311-nm channels (2-nm FWHM). The total uncertainty of ozone retrievals in this study is +/-2.0%. For Mauna Loa the mean ratios of the UV-MFRSR column ozone retrievals to the collocated Dobson and Brewer were 0.998 and 0.986 between May and September of 1999. The mean ratio of UV-MFRSR retrievals to the collocated Brewer retrievals was 1.012 in Toronto between April and August of 1999, and the mean ratio of retrievals of the UV-MFRSR to the collocated Brewer was 0.988 in Regina between June and September of 1999. Total vertical column ozone values for solar zenith angles of >70 degrees were not considered, because of the signal-to-noise ratio and the angular response of the instruments, and were not used in the evaluation. The advantages of total vertical column ozone retrieval using UV-MFRSR include relatively low cost, computer-controlled operation, automated calibration stability checks, and minimal maintenance. It allows for the real-time measurement of total vertical column ozone. The UV-MFRSR is being used at 28 sites across the United States and 2 sites in Canada that form the U.S. Department of Agriculture UV-B Radiation Monitoring and Research Program. This constitutes a unique network of total vertical colunm ozone measurement.

Journal Article↗
PubMed1993

Comparative evaluation of six rapid serological tests for HIV-1 antibody.

Six commercial rapid test kits for HIV-1 antibody were evaluated. Four laboratory technologists tested sera from four groups of U.S. military personnel or dependents: 202 subjects positive for HIV-1 antibody by Western blot, 200 seronegative voluntary blood donors, 199 seronegative obstetrics/gynecology patients, and 99 subjects with sera reactive by ELISA but negative by recombinant protein EIA and indeterminate by Western blot. The three tests using solid-phase immunoassay technology demonstrated the highest mean sensitivity (> 99%) and specificity (> 91%) for all groups tested, including sera indeterminate by Western blot. Two dot-immunoblot assays were less specific, possibly due to indistinct reaction end points, and a latex agglutination assay was also less specific because of difficulty distinguishing reactive results from the granular background. In an "ease-of-use" assessment, solid-phase capture immunoassays required less time and equipment and were easier to interpret than other testing methods. Solid-phase capture immunoassays for HIV-1 antibody may be suitable for use in emergency situations and in developing countries because they are highly sensitive and specific and are rapidly performed with minimal laboratory equipment.

AIDS Serodiagnosis↗
PubMed1992

The cost of fragmented mental health financing: is it worth it?

Three major aspects of mental health systems--the way they are financed, the configuration of services, and the outcome of services--are discussed. Problems of resource consumption, fragmentation of goals, and deleterious impacts due to financing systems, per se, are described. Levels of staff involvement in the financing system (as distinct from direct services) influence staff attitudes toward financing, services, and clients. Financing schemes appear to both influence the effectiveness of mental health systems and provide the dubious "advantage" of costing more. Studies are suggested that will compare comprehensive systems with an eye toward reform.

Chronic Disease↗
PubMed1985

Glutathione peroxidase activity in surgical and autopsied human brains.

Glutathione peroxidase (GSHPx) activity was assayed in normal cerebral gray and white matter samples obtained from frontal, temporal, occipital and parietal lobes during surgical approach to an underlying lesion, and also in normal autopsied human frontal gray and white matter. GSHPx was assayed by a 2 step enzyme reaction which was monitored by following the oxidation of NADPH at 340 nm. It was found that all the brain samples studied contained GSHPx activity. Parietal lobe appeared to have the lowest GSHPx activity compared to temporal, occipital or frontal lobes. Mean enzyme activity in autopsied samples was comparable to that in surgical material. However, considerable loss of activity was observed after 10 years of tissue storage at -80 degrees C.

Adult↗
PubMed1982

Glutathione peroxidase in human cerebrospinal fluid.

Glutathione peroxidase activity was investigated in human cerebrospinal fluid. CSF was obtained from 23 male adult patients with dementia, cerebrovascular disease and multiple sclerosis. The mean glutathione peroxidase activity in the CSF was 6.2 nmol NADPH oxidized min-1 . mg-1 protein +/- 0.6 S.E.M. No differences in the activities were observed in these neurological diseases suggesting that this value may reflect normal glutathione peroxidase activity in human CSF. The age or the protein concentration in CSF did not correlate significantly with glutathione peroxidase activity in CSF.

Adult↗