Greenland ice evidence of hemispheric lead pollution two millennia ago by greek and roman civilizations

Analysis of the Greenland ice core covering the period from 3000 to 500 years ago-the Greek, Roman, Medieval and Renaissance times-shows that lead is present at concentrations four times as great as natural values from about 2500 to 1700 years ago (500 B.C. to 300 A.D.). These results show that Greek and Roman lead and silver mining and smelting activities polluted the middle troposphere of the Northern Hemisphere on a hemispheric scale two millennia ago, long before the Industrial Revolution. Cumulative lead fallout to the Greenland Ice Sheet during these eight centuries was as high as 15 percent of that caused by the massive use of lead alkyl additives in gasoline since the 1930s. Pronounced lead pollution is also observed during Medieval and Renaissance times.     

Chemical Composition of the Lunar Surface in a Terra Region near the Crater Tycho

More precise and comprehensive analytical results for lunar surface material in a terra region have been derived from the data of the alpha-scattering experiment on Surveyor 7. The silicon content and the low sodium abundance are close to that of mare material. The abundances of titanium and iron are at least a factor of 2 lower, whereas the abundances of aluminum and calcium are significantly higher. The analytical results provide direct evidence for chemical differentiation in the moon and indicate a lunar crust of appreciably lower density than the whole moon and with lower density and higher albedo than lunar mare material.     

Chemical composition of the lunar surface in sinus medii

More precise and comprehensive analytical results for lunar material in Sinus Medii have been derived from the alpha-scattering experiment on Surveyor VI. The amounts of the principal constituents at this mare are approximately the same as those of constituents at Mare Tranquillitatis. The sodium contents of both maria are lower than those of terrestrial basalts. The titanium content at Sinus Medii is lower than that at Mare Tranquillitatis; this suggests important differences in detailed chemical composition at different mare areas on the moon.     

Presence and impact of the exercise-induced collapse associated DNM1 mutation in Labrador retrievers and other breeds

The impact of the mutation causing dynamin 1 (DNM1)-associated exercise-induced collapse (d-EIC) was determined in a retrospective genetic survey. The frequency of DNM1 mutant allele carriers in Labrador retrievers from conformation show, field trial/hunt test, pet or service lines ranged from 17.9% to 38.0% and the frequency of homozygous mutant (EE genotype) individuals ranged from 1.8% to 13.6%; 83.6% of these EE Labradors were reported to have collapsed by 4 years of age. DNM1 mutation carriers and EE dogs with a collapse phenotype were also detected in Chesapeake Bay retrievers, Curly-coated retrievers, Boykin spaniels, Pembroke Welsh corgis and mixed breed dogs thought to be Labrador retriever crosses. The DNM1 mutation was not identified in Golden, Flat-coated, or Nova Scotia duck tolling retrievers, or 15 other non-retrieving breeds. Veterinarians and breeders should be aware that the DNM1 EE genotype is not completely penetrant and that d-EIC is a widespread health concern in several very popular breeds, as well as breeds whose genetic similarity to retrievers is not obvious.     

High Performance Thin Layer Chromatography (HPTLC) profile of an insecticidal compound of <Emphasis Type="Italic">Trochus radiatus</Emphasis> and assessment of mucus-associated bacterial extracts

The current study is based on the screening of novel insecticides from new sources that have not being exploited hitherto. The major objectives of this research work were to extract marine molluscs, Lambis lambis, Trochus radiatus and Chicoreus ramosus, from Tuticorin coastal waters using different solvents to test their insecticidal properties and partially purify the active components. The ethyl acetate extracts of L. lambis and T. radiatus showed 100% mortality of Sitophilus oryzae, at a concentration of 200 μg ml⁻¹. The LC₅₀ values for ethyl acetate extracts of L. lambis, T. radiatus and C. ramosus were found to be 67.08, 348.86 and 571.42 μg ml⁻¹, respectively. With regard to bacterial metabolites, at a concentration of 200 μg ml⁻¹ the ethyl acetate extract of A3 was able to elicit an activity of 40% and that of strain A1 – 20%. The LC₅₀ values of the bacterial metabolites were also investigated. Upon chromatographic separation of active ethyl acetate extracts of T. radiatus, the 100% methanol column-purified fraction was found to have an activity of 30% at a concentration of 10 μg against S. oryzae. The purity of the partially pure active compound was observed to be 72.78% on analysis with high pressure thin layer chromatography.     

Effects of grinding and storage for one month on retention of vitamin A in premixes and mineral supplements

Tested standardized procedures for handling premixes and mineral supplements from time of sampling to time of analysis for vitamin A have not been developed, which could account for some unexplained inconsistent and low analytical results. Grinding premix samples and storing them in a freezer for one month had little effect on amount of vitamin A found, but there was a significant loss (about 10%) after storage for one month at room temperature. Results on replicated determinations of vitamin A in unground and ground mineral supplements and on effect of storage were somewhat more variable than for premixes, but only the loss (about 12%) during storage for one month at room temperature was significant.     

Mycotoxins in animal feedstuffs: sensitive thin layer chromatographic detection of aflatoxin, ochratoxin A, sterigmatocystin, zearalenone, and T-2 toxin

Improvements have been made to a previously described multi-mycotoxin method that involved a membrane cleanup step. Using 2-dimensional thin layer chromatography and appropriate solvent systems, aflatoxin B1 can be detected in mixed feedstuffs and various ingredients at levels ranging from 0.1 to 0.3 microgram/kg. Corresponding detection limits for ochratoxin A and sterigmatocystin are 5 to 20 microgram/kg and for T-2 toxin and zearalenone 20 to 200 microgram/kg.