Rapid eruption of the siberian traps flood basalts at the permo-triassic boundary

The Siberian Traps represent one of the most voluminous flood basalt provinces on Earth. Laser-heating (40)Ar/(39)Ar data indicate that the bulk of these basalts was erupted over an extremely short time interval (900,000 +/- 800,000 years) beginning at about 248 million years ago at mean eruption rates of greater than 1.3 cubic kilometers per year. Such rates are consistent with a mantle plume origin. Magmatism was not associated with significant lithospheric rifting; thus, mantle decompression resulting from rifting was probably not the primary cause of widespread melting. Inception of Siberian Traps volcanism coincided (within uncertainty) with a profound faunal mass extinction at the Permo-Triassic boundary 249 +/- 4 million years ago; these data thus leave open the question of a genetic relation between the two events.     

Floral blight of gram incited by Alternaria alternata

Samenvatting In de groeiseizoenen 1970–'71 en 1971–'72 werd op de proefboerderij van de Hindu Universiteit van Benares (India) een ernstige bloemaantasting waargenomen bij de grauwe Spaanse erwt (Cicer arietinum L). Hierdoor werd het aantal peulen per plant sterk gereduceerd. Op de aangetaste bloemen (Fig. 1) sporuleerde in een later stadium een schimmel die werd geïsoleerd. Inoculatie van jonge bloemknoppen met sporesuspensie van deze schimmel, die werd geïdentificeerd alsAlternaria alternata (Fr.) Keissler (Fig. 2), veroorzaakte weer dezelfde symptomen.     

Overexpression of metallothionein confers resistance to anticancer drugs

Resistance to antineoplastic agents is the major obstacle to curative therapy of cancer. Tumor cell lines with acquired resistance to the antineoplastic agent cis-diamminedichloroplatinum(II) overexpressed metallothionein and demonstrated cross-resistance to alkylating agents such as chlorambucil and melphalan. Human carcinoma cells that maintained high levels of metallothionein because of chronic exposure to heavy metals were resistant to cis-diamminedichloroplatinum(II), melphalan, and chlorambucil. Furthermore, cells transfected with bovine papilloma virus expression vectors containing DNA encoding human metallothionein-IIA were resistant to cis-diamminedichloroplatinum(II), melphalan, and chlorambucil but not to 5-fluorouracil or vincristine. Thus, overexpression of metallothionein represents one mechanism of resistance to a subset of clinically important anticancer drugs.     

Rapid determination of the critical temperature in simulated annealing inversion

Knowledge of the critical temperature, T(*), the temperature at which a phase change occurs, greatly improves the efficiency of simulated annealing when used for optimization or inversion. A numerical method of accurately determining T(*) in a relatively short computation time has been developed. This method is used to recover the seismic soundspeed profile from wavefield data, a problem in which cycle skipping causes many local minima of the energy function and the averaging of the medium by finite length waves results in many states with similar energies. Computations indicate that it is cost-effective to spend about 80 percent of the computing budget looking for T(*) instead of annealing, and that in the course of finding T(*) many states with energies near the global minimum will also be found. The a posteriori probability distribution of the solution has been constructed from trial solutions generated at T(*).     

A new leaf spot of maize incited byCurvularia clavata

In September 1969 a leaf spot of maize Composite Jawahar, incited byC. lavata Jain, was observed at the College Farm of the Banaras Hindu University, Varanasi. The fungus seriously damages maize leaves and considerably reduces its fodder value. The symptoms of the disease and taxonomic characters of the pathogen are being described in detail.Samenvatting Een belangwekkende bladvlekkenziekte op Composite Jawahar maïs, veroorzaakt doorCurvularia clavata Jain, werd waargenomen op de College Farm van de Banaras Hindu University te Benares in september 1969. De schimmel brengt ernstige schade toe aan maïsbladeren en vermindert aanzienlijk de waarde als voedergewas. Een beschrijving van de ziektesymptomen en van de schimmel wordt gegeven.     

Stress Factors Can Reverse the Pinealostimulatory Effect of 6-hydroxydopamine on the Pineal Gland of Blossomheaded Parakeet (Psittacula cyanocephala)

A study of the pineal gland of adult male blossomheaded parakeets was conducted with the aid of light microscopic examination to determine the influence of stress on pineal cells. It was demonstrated that stress decreased the growth and activity of the pinel cells when induced as hyperosmolality (water deprivation, salt ingestion). This influence on the pineal gland was not inhibited by previous treatment of a sympatholytic agent, 6-hydroxydopamine.     

Maternal recognition of pregnancy--a review of the literature

A review of the literature concerning the endocrinological changes around early pregnancy in the domestic animals is presented. During this period the presence of the blastocyst must be recognized by the mother ("Maternal Recognition of Pregnancy") leading to a rescue and maintenance of the corpus luteum function. Several hormones are involved in these processes and the initial hormonal changes are dependent on a viable blastocyst. The key event is its control of the prostaglandin synthetizing system.     

Larvicidal activity of Solanum villosum Mill (Solanaceae: Solanales) leaves to Anopheles subpictus Grassi (Diptera: Culicidae) with effect on non-target Chironomus circumdatus Kieffer (Diptera: Chironomidae)

Chloroform-methanol extract of mature leaves from Solanum villosum Mill (Solanaceae: Solanales) was investigated to establish its biocontrol potentiality under laboratory condition against larval forms of Anopheles subpictus Grassi (Diptera: Culicidae), the vector of human malaria. All the graded concentrations (30, 50, 100 and 200 ppm) showed significant (P < 0.05) larval mortality and results of regression equations revealed that the mortality rates were positively correlated with the concentrations of the extract (R ² close to 1). LC₅₀ values for all instars were between 24.20 and 33.73 ppm after 24 h and between 23.47 and 30.63 ppm after 48 h of exposure period. Significant changes in the larval mortality (F < 0.05) was also recorded between instars during single “ANOVA” analysis. This extract also demonstrated no toxicity to larvae of Chironomus circumdatus Kieffer (Diptera: Chironomidae) which were found to be present as most common non-target dipteran insect in the habitats of A. subpictus. Qualitative and chromatographic analysis of the solvent extract revealed the presence of carbohydrates, saponins, terpenoids, volatile oil, steroids, phenols and flavonoids as major bioactive phytochemicals.