Middle tertiary volcanism during ridge-trench interactions in Western california

Bimodal volcanism in the Santa Maria Province of west-central California occurred when segments of the East Pacific Rise interacted with a subduction zone along the California margin during the Early Miocene (about 17 million years ago). Isotopic compositions of neodymium and strontium as well as trace-element data indicate that these volcanic rocks were derived from a depleted-mantle (mid-ocean ridge basalt) source. After ridge-trench interactions, the depleted-mantle reservoir was juxtaposed beneath the continental margin and was erupted to form basalts. It also assimilated and partially melted local Jurassic-Cretaceous sedimentary and metasedimentary basement rocks to form rhyolites and dacites.     

Evidence for genetic linkage of Alzheimer's disease to chromosome 10q

Recent studies suggest that insulin-degrading enzyme (IDE) in neurons and microglia degrades Abeta, the principal component of beta-amyloid and one of the neuropathological hallmarks of Alzheimer's disease (AD). We performed parametric and nonparametric linkage analyses of seven genetic markers on chromosome 10q, six of which map near the IDE gene, in 435 multiplex AD families. These analyses revealed significant evidence of linkage for adjacent markers (D10S1671, D10S583, D10S1710, and D10S566), which was most pronounced in late-onset families. Furthermore, we found evidence for allele-specific association between the putative disease locus and marker D10S583, which has recently been located within 195 kilobases of the IDE gene.     

Intensive observations on the effect of some insecticides on Nephotettix virescens (Distant), a vector of virus and MLO diseases,with special reference to its transmission ability

The effects of some insecticides on Nephotettix virescens (Distant), a leafhopper vector of virus and MLO diseases, were studied with particular reference to their efficacy in affecting vector behaviour and transmission of rice tungro virus (RTV). When 10- and 15-day old seedlings from carbofuran-treated seeds were exposed to viruliferous vectors in cages, the percentages of transmission were 40 and 50, respectively against cent per cent in the control. Spraying of EC formulations of dimethoate, phosphamidon and methamidophos was not effective but decemethrin showed spectacular knockdown effect and gave absolute protection against RTV transmission upto 7 days. Since the transmission threshold of RTV is considerably shorter than of mycoplasmal diseases, the treatments affecting RTV transmission may reasonably be expected to be quite effective against MLO diseases like rice yellow dwarf and sandal spike, transmitted by N. virescens.     

Clinical and endocrine responses to embryonic and fetal death induced by manual rupture of the amniotic vesicle during early pregnancy in cows

Pregnancy was terminated in 4 cows by manual rupture of the amniotic vesicle on day 41 (n = 1) and day 46 (n = 3) after insemination. Each cow was necropsied 36 days after vesicle rupture, by which time only one cow had come into estrus. Luteal activity, monitored daily by plasma progesterone assay, was still evident in 2 cows 35 days after fetal death; in the remaining 2 cows, regression of the corpus luteum (CL) was achieved at 28 and 32 days, respectively. Uterine release of prostaglandin F2 alpha (PGF2 alpha), measured as the 15-keto metabolite (PGFM) PGF2 alpha, was monitored by a plasma sampling schedule; specimens were obtained every 4 hours. There were no appreciable releases of PGF2 alpha associated with fetal death. The first appreciable PGF2 alpha release in episodic form was seen only in conjunction with CL regression. In all cows, a palpable membrane slip was evident for 18 days after rupture of the amniotic vesicle, although at that time, uterine resilience was diminished in the 2 cows in which the CL subsequently regressed. After 18 days, the uterus was noticeably edematous and fluid-filled in all cows; in 1 of the cows with a regressed CL, the uterus had returned to prepregnancy size and tone by day 33.(ABSTRACT TRUNCATED AT 250 WORDS)     

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(*).     

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.