Detection of a gonadotropin in rabbit blastocyst before implantation

A gonadotropin similar to human chorionic gonadotropin or luteinizing hormone has been demonstrated in rabbit blastocyst prior to implantation. The gonadotropin has been detected by a radioreceptor assay for human chorionic gonadotropin with the use of the plasma membranes of bovine corpora lutea obtained during the first trimester of pregnancy. The concentrations of the human chorionic gonadotropin or luteinizing hormone per milliliter of blastocyst fluid were tenfold higher than those in the blood of pregnant rabbits on days 5 and 6 after mating.     

Stability of Ferropericlase in the Lower Mantle

We have heated ferropericlases (Mg(0.60)Fe(0.40))O and (Mg(0.50)Fe(0.50))O to temperatures of 1000 kelvin at pressures of 86 gigapascals, simulating the stability of the solid solution at physical conditions relevant to Earth's lower mantle. The in situ x-ray study of the externally heated samples in a Mao-Bell-type diamond anvil cell shows that ferropericlase may dissociate into magnesium-rich and iron-rich oxide components. The result is important because the decomposition of ferropericlase into lighter and heavier phases will cause dynamic effects that could lead to mantle heterogeneity.     

Entropy Estimates for Some Silicates at 298{degrees}K from Molar Volumes

Third law entropies for silicates of Be, Mg, Ca, Zn, Na, and K containing the same anion group, for example, SiO(4) or SiO(3) or AlSi(3)O(8), are found to be linearly related to their molar volumes. The relationship between the molar volume and the entropy of silicates of Fe and Mn, atoms with unfilled d electron subshells, is different from that of other silicates. The linear correlations yield a useful method of estimating the entropies of ortho-, meta-, and framework silicates (feldspars and feld-spathoids). The estimated entropies of pyrope and almandine at 298 degrees K are 47.47 and 68.13 gibbs per mole, respectively.     

Effect of long-term manuring and fertilizers on carbon pools,soil structure,and sustainability under different cropping systems in wet-temperate zone of northwest Himalayas

We investigated C management index (CMI; an indicator of sustainability of a management system and is based on total and labile C) and soil aggregation in medium-textured soils (silt loam and silty clay loam) under different cropping systems as follows: maize-wheat (M-W), rice-wheat (R-W), soybean-wheat (S-W), Guinea grass, and Setaria grass. Field experiments were 6–32 years long and were located in the wet-temperate zone of northwest Himalayas. The plant nutrients were applied through chemical fertilizers (urea, superphosphate, and muriate of potash) with or without organic materials (FYM, wheat straw, and Lantana spp.). The content of total C (C_T), labile C (C_L), CMI, mean weight diameter (MWD), and aggregate porosity varied significantly under different cropping systems. The range was 1.59 (R-W)–4.29% (Setaria) for C_T, 1.23 (R-W)–3.89 mg/kg (Guinea grass) for C_L, 52.09 (R-W)–129.77 (Guinea grass) for CMI, 0.90 (R-W)–5.09 (Guinea grass) for MWD, and 41.5 (R-W)–56.8% (S-W) for aggregate porosity. Aggregate porosity was highest (56.8%) under S-W, followed by grasses (50.1–51.2%), and M/R-W (41.5–50.0%). As per these data, (a) continuous use of N alone as urea lowered soil sustainability over control (no fertilizers); (b) use of NPK at recommended rates improved soil productivity over control; (c) the NPK + organic amendments further improved soil sustainability; and (d) the sustainability under different cropping systems followed the order: perennial grasses > soybean-wheat > maize-wheat > rice-wheat.     

Uptake and bioconcentration of dieldrin,dimethoate, and permethrin by Tetrahymena pyriformis

A ciliate protozoan, Tetrahymenapyriformis was exposed to three insecticides, dieldrin, dimethoate, and permethrin for 12 hr to study the uptake and bioconcentration potential. Ciliates concentrated 922, 3547, and 1056 gg g^?1 dry wt. over an initial concentration of 1 gg mL^?1 of dieldrin, dimethoate, and permethrin, respectively. The highest bioconcentration factor for three insecticides was 2095, 3547, and 1110, respectively. It is suggested that if levels in the environment reach 1 gg mL^?1 the chief effects would be reduction of cell population, and accumulation of the toxicants by ciliates. Accumulation of insecticides by ciliates would permit the toxicants to enter aquatic food chains. Thus the compounds could exert toxic effects at higher trophic levels.     

Effect of parbendazole and piperazine adipate on the activity of some enzymes of Ascaridia galli and Heterakis gallinae

Adult Ascaridia galli and Heterakis gallinae obtained from the fowl (Gallus gallus) were treated in vitro with 10(-2) to 10(-5) M parbendazole and piperazine adipate for 10-60 min at 38 degrees C. Both the compounds at 10(-2) M caused mortality of A. galli and H. gallinae after a maximum of 30 min exposure. The effect of the drugs on the homogenates of the treated worm was investigated. Parbendazole (10(-2) M) inhibited malate oxidation by 68% in A. galli and 62% in H. gallinae. Piperazine adipate (10(-2) M) inhibited malate oxidation by 78% in both parasites. In A. galli oxaloacetate reduction was inhibited by 41 and 26% by 10(-2) M parbendazole and piperazine adipate, respectively; with H. gallinae this inhibition was found to be 39 and 55%, respectively. Aldolase activity in both the parasites was also inhibited by 10(-2) M parbendazole and piperazine adipate. Both compounds caused an inhibition of acid phosphomonoesterase activity, but the activities of lactate dehydrogenase and alkaline phosphomonoesterase were not affected significantly. Parbendazole (10(-2) M) had no significant effect on the cholinesterase activity of these parasites, but piperazine adipate (10(-2) M) caused an inhibition of 96% in A. galli and 93% in H. gallinae. The possible mode of action of the drugs is discussed.     

Colonization of rice fields by Nilaparvata lugens (Stål) and its control using a trap crop

Colonization of rice fields by the brown planthopper, Nilaparvata lugens (Stål) (Homoptera: Delphacidae), was monitored using yellow pan oil-water traps. In approximately 3 months, 35 788 immigrant macropters (1·0 ♂: 1·2 ♀) were caught in 512 traps installed over a 0·352 ha rice field. The trend of daily trap catches conformed closely to the number of macropters visually counted on rice hills. In sub-plots with a trap crop planted 20 days earlier than the main crop on a quarter of the total crop area, more macropters were recorded on trap-crop than on main-crop rows up to about 75 days after transplanting the main crop. In control sub-plots with one planting, more hoppers arrived on the middle than on the border rows. A blanket spray application of Perthane (0·75 kg a.i./ha) was made on the crop in control sub-plots, whereas only the trap crop was sprayed in trapped sub-plots. The combined yield in each treatment with trap crop was significantly higher than in the control treatment.