Formation of Carbon-Carbon Bonds in the Photochemical Alkylation of Polycyclic Aromatic Hydrocarbons

The reaction of polycyclic aromatic hydrocarbons (PAHs) withalkanes was examined in the presence of ultraviolet (UV) lightunder model prebiotic Earth and interstellar medium (ISM)conditions. We observed the formation of alkylated PAHs from avariety of PAHs and alkanes, which was caused by the absorptionof UV light by the PAH molecule. Photoalkylation occurred inPAHs and alkanes in solution, in thin films in contact withsimulated ocean water, and in matrices simulating ISMconditions. Photoalkylation occurred readily, with significantproduct yields within 5 h of irradiation. Because alkanes andPAHs are presumed to be part of the organic inventory in the ISMand on the early Earth, we propose that this photoalkylation reactionis a plausible pathway for the formation of carbon-carbon bondsin both these environments.     

Origin and Development of Neutrophils in an Air Breathing Fish,Channa punctatus Bloch

Mahajan, C. L., Dheer, J. M. S. 1980. Origin and development of neutrophils in an air breathing fish, Channa punctatus Bloch. (Department of Zoology, University of Rajasthan, India.) — Acta zool. (Stockh.) 61(4): 221–224. An account of the study of the development of neutrophils based on detailed examinations of kidney and spleen imprints has been given in this paper. Each developmental stage has been investigated with respect to its morphology, morphometry and cytochemistry using certain special techniques developed in this laboratory for fishes such as differential haemoglobin staining, autoradiography etc. Five main stages (large lymphoid haemoblasts, promyelocytes, mesomyelocytes, metamyelocytes, mature neutrophils) have been identified in development and are described in detail.     

Sucrose metabolism in developing endosperm of immature wheat (Triticum aestivum L.) grain

With a view to investigating the role of the enzyme pyrophosphate-fructose-6-phosphate-1-phosphotransferase (PFP) in sucrose breakdown in developing endosperm of wheat grain, the activity of PFP and related enzymes such as phosphofructokinase (PFK), fructose-6-bisphosphatase (FBPase), fructose-6-phosphate-2-kinase (PFK-2) and fructose-2,6-bisphosphatase (F2, 6-P2ase) and the contents of the various intermediates of the pathway serving either the substrate or the effectors of these enzymes such as glu-6-P,glu-1-P,fru-6-P,fru-1,6-P2,DHAP,G3P, UDP-glucose, ADP-glucose, Pi,PPi and fru-2,6-P2 have been determined at 5 days intervals starting from day-5 after anthesis until day-40 after anthesis. These enzymes except PFK-2 had their peak activity at day-25 after anthesis. The activity of PFP was several fold higher than that of PFK at each stage of grain development. PFK-2 exhibited the lowest activity. The various intermediates again had their maximum concentration either at day-20 or day-25 after anthesis. Among hexose phosphates studied, glu-6-P was present in highest concentration at each stage of grain development. The level of Pi was much higher than those of PPi and fru-2,6-P2. Similarly, concentration of UDP-glucose was higher than that of ADP-glucose. Based on these results, it is proposed that the major role of the enzyme PFP in developing wheat grain is to provide PPi for sucrose breakdown via sucrose synthase.     

Almost Unbiased Ratio and Product Type Estimators: A New Approach

In this paper, we have proposed a new method, consisting of a linear variety of the estimators and a linear constraint to remove the bias appearing in the estimators of the ratio R = Y/X and product P = YX. The percent relative efficiency of proposed estimators has also been demonstrated with numerical illustrations.     

Seasonal intensity of Angiostrongylus cantonensis in the intermediate host, Laevicaulis alte.

The slug, Laevicaulis alte, is a vector of Angiostrongylus cantonensis in the Greater Bombay area. The seasonal prevalence of A. cantonensis was investigated to determine the maximum intensity of the parasite in a field population occupying an area of approximately 400 m2. The maximum intensity of larvae was observed in the rainy months, June-November. Investigations showed that individual L. alte could tolerate an infecting dose of 150 first-stage A. cantonensis larvae before mortalities occurred.     

A low frequency active filter with plug-in tuning impedances.

A new approach to the construction of low frequency (1 Hz -- 20 kHz) active filters, based on the application of a pair of IC operational amplifiers forming a separate module and a plug-in unit containing RC tuning circuits, is described. The electronic circuits and the design of the filters are presented with all details.