Extracts of two species of green algae, filamentousRhizoclonium hieroglyphicum Kütz and a phytoplankton,Chlorella ellipsoidea Gerneck, obtained with solvents in the laboratory were assayed againstAedes aegypti L.,Culex quinquefasciatus Say, andCuliseta incidens (Thomson). On extraction with petroleum ether, groundR. hieroglyphicum yielded an active crude extract which was chromatographed on a neutral alumina column and eluted consecutively with petroleum ether, benzene, and methanol. All three eluted fractions were found to induce significant mortality in test mosquito species. The benzene-eluted fraction was the least toxic. The methanol-eluted fraction was the most toxic to all species and exhibited juvenile hormone-like activity; it also caused morphogenetic changes in emerging adults. All three fractions delayed the rate of development of mosquito larvae by 2-5 days. Three supernatants ofC. ellipsoidea obtained on different occasions were tested against first instars ofC. quinquefasciatus. After the confirmation of their activity, all supernatants were extracted with diethyl ether, combined, and assayed against first- and fourth-stage larvae of the three mosquito species. The first-stage larvae ofC. quinquefasciatus andC. incidens were approximately three times more suspectible than those ofA. aegypti. However, fourth-stage larvae of the former two species were about twice as susceptible to the extract as those of the latter species. Dead first-stage larvae of all the species had a shrunken appearance. In general,C. ellipsoidea extract was quicker acting than that ofR. hieroglyphicum.

Results of this study show that the volar cortex was statistically, significantly thicker than the dorsal cortex. We believe that the volar cortex may behave as the calcar of the distal radius and hence internal fixation devices applied to the volar cortex may provide a more stable internal fixation compared to those based on the dorsal cortex.

Fifty lateral radiographs of normal wrists were viewed to determine the palmar cortical angle of the distal radius. The palmar cortical angle is different to its previously described palmar tilt or angulation. The mean value for the palmar cortical angle was 37 degrees (range, 26-50 degrees). This may be clinically important in the design of palmar plates for the distal radius.

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An extract of the hydrophyteMyriophyllum spicatum L. was found to be toxic to first- and fourth-instar larvae of the mosquitoes,Culex quinquefasciatus Say,Culex tarsalis Coquillett,Culiseta incidens (Thomson),Aedes aegypti L., and chironomid midges in the laboratory. When first-stage larvae were exposed to the extract, the lowest concentration (6.4 mg extract/100 ml H2O) produced 86,60, and 48% mortality inC. incidens, C. quinquefasciatus, andA. aegypti, respectively. Higher concentrations caused 100% mortality in both first and fourth instars (63.75 mg/100 ml H2O or more). In general, the biocidal activity of the extract was found to be similar when first- and fourth-stage larvae were exposed. Some mortality in the successive pupal and adult stages was observed when fourth-stage larvae were exposed to the extract, but mortality occurred only in the various larval instars when first instars were exposed. Among the chironomids,Tanytarsus spp. was more tolerant to the extract thanChironomus spp. In addition to the biocidal activity against immature mosquitoes, the extract was found to show a unique activity acting as an attractant to both sexes of adultC. quinquefasciatus andA. aegypti. The response elicited inA. aegypti appeared to be somewhat higher than that inC. quinquefasciatus. In general, the percentage of males responding to water treated with the extract was higher than that of the females. The extract at higher concentrations seemed to show some repellency at the outset to both species, but induced positive responses later on.