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B V Brown

Publications and source records attributed to B V Brown.

4 recordsLinked to original sources
PubMed2000

The species of Phora (Diptera: Phoridae) of Costa Rica.

The Phora of Costa Rica were reviewed and three species, all belonging to Schmitz's Group III, were recognized: P. americana Schmitz and Wirth, P. truncata new species and P. paramericana new species. Of the three species, P. americana is by far the most abundant, with the other two species being rarely collected. All specimens were collected in the central highlands of the country. The previous record of the Holarctic Region species P. stictica Meigen from Costa Rica was found to be based on a misidentification of P. truncata.

Animals↗
PubMed1997

Diptera as parasitoids.

Parasitoids in the insect order Diptera include an estimated 16,000 species, or approximately 20% of the total number of species with this life-style. Parasitoids in this order are exceedingly diverse in both their habits and evolutionary origins, which makes them an underutilized but highly suitable group for quantitative studies of character convergence and adaptive radiation. This review focuses on several aspects of the bionomics of dipteran parasitoids that have received little comprehensive treatment, including processes associated with host location and attack, patterns of host use, and the evolutionary and ecological consequences of host-parasitoid interactions. Throughout the review we contrast the patterns found within the parasitic Diptera against those found in the better studied parasitic Hymenoptera. We conclude that more intensive study of dipteran parasitoids is required before we can understand the general conditions that favor the evolution of insect parasitoids and the truly magnifying themes of their behavior and ecology.

Journal Article↗
PubMed1985

Psoralens increase the concentration of cyclic AMP in human cells in vitro.

8-Methoxypsoralen (8-MOP) and 4,5',8-trimethylpsoralen (TMP) were assessed for their effects on cyclic AMP (cAMP) accumulation in normal human fibroblasts, epithelial cells, and mononuclear leukocytes in vitro. In the absence of ultraviolet A radiation, 8-MOP and TMP caused an increase in the concentration of cAMP, but not cyclic GMP, in all of these cells. The effect was seen within 1 min and was sustained over control levels for at least 6 h. At 15 min, the highest dose of 8-MOP or TMP increased the cAMP concentration of fibroblasts by 52% and 69%, respectively. In mononuclear leukocytes, 8-MOP led to a 142% increase in cAMP after 20 min. Several analogs of 8-MOP and TMP had no effect on the cyclic nucleotide system of the cells. The pattern of the time-dependent increase in cAMP indicated that the effect was probably due to an inhibition of phosphodiesterase, rather than an activation of adenylyl cyclase. These results demonstrate that clinically effective psoralens, in the absence of UV radiation, can alter the cAMP concentration of human fibroblasts, epithelial cells, and mononuclear leukocytes in vitro.

Cyclic AMP↗