Showing papers by "University of Rajasthan published in 1969"

Sclerospora graminicola Axenic Culture

Abstract: Sclerospora graminicola (Sacc.) Schroet., the obligate pathlogen causing downy mildew (green-ear) of pearl millet (Pennisetum typhoides Stapf. and Hubb.) has been successfully cultured for the first time on a known semisynthetic mediumn with no evident loss of fructifications. Sclerospora graminicola was first grown on host callus tissue and subsequently on a modification of White's basal medium that contained casein hydrolyzate (Oxoid). 2,4-dichlorophenoxyacetic acid, and kinetin.

Alkoxides and Double Alkoxides of Zinc

Abstract: Zinc methoxide and isopropoxide were prepared by the reaction of zinc chloride with the appropriate lithium alkoxide and a few other alkoxides, Zn(OR) 2 (where R = Et, Bu n , Bu t and C 8 H 17 n ) have been synthesized by the alcoholysis of methoxide. All these alkoxides are non-volatile and insoluble in alcohols and other organic solvents. The non-formation of insoluble zinc ethoxide from zinc chloride by treating it with lithium ethoxide was found to be due to its complexing tendency with lithium chloride, giving soluble products of the type Li x Zn(OEt) 2 Cl x . A few soluble double alkoxides of lithium and zinc have also been isolated.

Reproduction in the Indian Desert Gerbil Meriones hurrianae Jerdon

Abstract: In the present study the whole sample of 772 desert gerbils was collected from the semi-arid areas in and around Jaipur (Rajasthan, India). The male exhibits active spermatogenesis and well maintained accessory reproductive organs at any time of the year. Reproductive organs of the male gerbil are briefly described. The vaginal and urinary openings are independent in the gerbil. There are four pairs of mammae. Follicular development takes place cyclically. Maximum atresia of follicles is noticed during metoestrus. A well developed Graafian follicle measures 590 μ across its widest diameter. The average diameter of the ovum is 65 μ. At the time of ovulation formation of stigma occurs which gives way to the ovum. The corpus luteum is formed from the remaining granulosa cells of the ovulated follicle. Fully formed corpus luteum of the cycle (during dioestrus) measures 740 μ. Maximum development of the corpus luteum is seen during late pregnancy (22–25 days) when it measures 1250 μ. During pregnancy large Graafian follicles are absent. After parturition the ovary shows corpora lutea of lactation. Histological changes in the uterus and vagina during the oestrous cycle of the gerbil are described. There is less proestrus distension of the uterus as compared with the rat. During oestrus the uterine endometrium hypertrophies and there are some degenerative changes in the epithelial lining. The changes in the vaginal epithelium are clear cut and are correlated with the ovarian activity. During proestrus proliferation of the epithelium occurs and at ‘heat period’ or oestrus the epithelium shows formation of the stratum corneum and the shedding of cornified cells. In the dioestrus the vaginal epithelium is heavily infiltrated by leucocytes. There are three peaks in the incidence of pregnancy rate, i.e., February to April, July, and September to November. Pregnancy rate is lowest during summer (May and June) and winter (December and January). Average monthly litter size shows almost similar changes. The average length of gestation period is 30 days. There is post-partum heat in this animal. Formation of a vaginal plug is noticed following copulation. Litter size varies from 2–7. The average body weight of the new born young is 3.5 and 3.4 gm respectively for the male and the female. Weaning of the young is observed after about 20 days. Descent of the testes into the scrotal sacs occurs around day 28. Vagina opens after about 75 days.

Halide alkoxides of beryllium

Abstract: The reactions of beryllium alkoxides, Be(OR) 2 , (where R = Et or Pr i ) with acetyl halide yields products with formulae, Be(OR)X· x ROAc and BeX 2 ·2ROAc ( X = Cl or Br and x = 0.5−0.7). The reactions of beryllium chloride with esters, e.g. , HCOOEt and ROAc, (R = Me, Et, Pr n , Pr i , Bu n and Bu sec. ) give diadducts. With tertiary butyl acetate however, beryllium acetate is the end product of the reaction.

Histopathology and Histochemistry of the Insects Treated with Chemosterilants

Abstract: The mature male grasshoppers (P. pictus) were injected 0.1 mg/insect of apholate in glass distilled water. Histopathological studies reveal no change after 12 hours treatment in testes. Spermatogonia, spermatocytes and spermatids show pycnotic nuclei, fragmentation of chromatin and vacuolization after 15 days of treatment. 24 and 30 days after treatment only cellular debris of the germ cells remained. The zone of transformation seems to have increased in length in earlier stages of treatment. Connective tissue cells and mature sperms show no histological damage.

Differentiation capacities of the prospective tail somite region of the neural plate in the embryos of Ambystoma mexicanum.

Abstract: The hind part of the neural plate in amphibian embryos has a mesodermal significance although it occupies an ectodermal position till late neurula stage. In anurans it gives rise to the posterior tail somites (Smithberg, 1954) and in urodeles the somites of the posterior trunk region and of the entire tail together with several other mesodermal structures (Bijtel, 1931; Nakamura, 1938; Aufsess, 1941; Spofford, 1945; Chuang, 1947; Ford, 1949). Presence of mesoderm in the neural plate is an interesting developmental problem. During normal gastrulation this region is at first underlaid by the future anterior part of the archenteric roof which exerts a neuralizing inductive influence. It is only later that the posterior part of the notochord with its mesodermalizing influence comes to lie under it. According to Eyal-Giladi (1954), who worked on gastrula stages of the Axolotl, even a short and transient contact of the invaginating archenteric roof with the overlying ectoderm produces archencephalic induction in the latter. It is therefore relevant to ask whether the posterior part of the neural plate does or does not pass through a phase of neuralization before assuming mesodermal properties. This specific question has not been investigated although a number of workers have studied the determination, differentition capacities or inductive properties of the caudal portion of the neural plate in amphibians (Bytinski-Salz, 1931; Bijtel, 1936, 1958; Chuang, 1947; Nakamura, 1947; Spofford, 1948; Smithberg, 1954). Spofford (1948) demonstrated that in Ambystoma mexicanum neurulae the tail notochord induces the overlying ectoderm to acquire mesodermal properties. He replaced the posterior part of the neural plate by a piece of competent ectoderm which itself had never been subjected to the influence of a neural inductor. This technique could demonstrate that, under experimental conditions, the so-called transformation or mesodermalization need not be preceded by activation or neuralization. These results, however, do not show whether this is also true during normal embryogenesis.

Thermal relaxation and heat transfer in non-polar gas mixtures

Abstract: The theory recently given by Saksena and Sharma in 1969 for the thermal conductivity of relaxing non-polar gases has been extended to mixtures involving non-polar polyatomic gases. Calculations have been performed on the systems O2-He, N2-He and O2-N2. The results obtained are in good agreement with the experimental values.

Thermal relaxation and heat transfer in non-polar polyatomic gases

Abstract: A theory for thermal conduction in polyatomic gases has been developed. The approach is similar to that of Hirschfelder in 1957 for chemically reacting gases, but it also takes into consideration the delayed exchange of energy between translational and internal degrees of freedom. The result obtained is identical with the one given by Saxena et al. in 1964, except for a numerical factor 2/3 which now appears in the term representing correction to the contribution of internal modes.

Polarographic studies on the Complexes of Cadmium and Lead with Adipic Acid

Abstract: Polarographic investigations on complexes of cadmium and lead with adipic acid have been carried out. The present study includes the effects of various parameters such as mercury pressure, temperature, concentration of metal ion, concentration of ligand, pH, surface active substances and viscosity on the waves. The plot of — E1/2 vs SCE and — log Cx is a curve (Fig. 2) showing the formation of more than one complex. The value of F3(X) is found to be constant (Table 1) which proves that three complexes are formed. Their overall stability constants have been calculated by using DEFORD and HUME'S method [2] and the values habe been found to be β1 = 16.5, β2 = 48.5, β3 = 116 ± 2. Along with this, effect of pH on pK1 (4.43) and pK2 (5.28) of adipic acid has also been investigated. The present work is also an attempt to describe the mechanism of the electrode process involved therein.

Some extensions of the general-relativistic particle model

Abstract: A stable model of a spherical charged particle in general relativity, based upon our previous work, is proposed. If one identifies this particle with the electron one gets, in its lowest excited mode, an energyE equivalent to 137me, which may be taken as the mass of then muon without spin.

Ventricular secretion of neurosecretory cells in Clarias batrachus Linn.

Abstract: und Rec tum sowie die Pericardialzellen dutch kurze Syntheseperioden ausgezeichnet, die allerdings zu ganz verschiedenen Zei tpunkten w~hrend des un te r such ten Larvens tad iums liegen. ~3ber gr613ere Zei tspannen verteilte DNSSyntheseaktivi tAt findet m a n in den Oenocyten und in den Malpighigef~Ben. Es muB hervorgehoben werden, dab die endomitot isch wachsenden Gewebe keinerlei Bieimblattspezifit~Lt hinsichtlich des Zei tpunkts der DNS-Synthese aufweisen. Bemerkenswer t ist ferner, dab eine ausgedehnte Syntheseaktivi t~t , abgesehen yon den Geweben mi t Blastemcharakter , nur bet den Versondrt~sen fiber den Zei tpunkt der H~u tung hinausreicht . ]3ei Lepidopteren [t] wurde gefunden, dab die DNS-Synthese nur in Anwesenhei t yon Eedyson ablaufen kann. Die hier wiedergegebenen Unte r suchungen lassen diese Annahme ffir Blasteme fraglich erscheinen. Zwar zeigen die meisten Gewebe eine Syntheseaktivit~it, nachdem ca. 60% der Zeit eines H~utungszyklus abgelaufen sind, doch gibt es einige, die schon frfiher damit beginnen (Malpighigef~ge, Fachzellen der Symbiontenorgane, V. cardiaca, V. pylorica) oder sp~iter (Versondrfisen, l leum, Rectum), so dab man den Zei tpunkt der Ausschfi t tung des H'~tutungshormons nicht als alleinigen Ausl6ser der DNS-Syn these ansehen kann. Es ist demnach ein zus/itzticher, gewebespezifischer Fak to r zu fordern, der die Syntheseakt ivi t~t in den einzelnen Geweben zeitlich modifiziert.

Spectrophotometric studies on chelate formation of copper(II) with picramine azo dyes: Applications in microanalysis

Abstract: Comparative studies of complex formation of Picramine azo dyes with copper(II) revealed that Picramine CA and Picramine R can be used as selective reagents for the microdetermination of 0.5 to 4.0 ppm of copper(II) in 0.1N hydrochloric acid medium. The absorbance reaches a constant value after about 5 minutes and remains so for about 24 hours. Studies show the formation of 1∶1 complexes with formation constants of the order of 105 and molar absorbances of the order of 1.25 · 104. The interference due to a number of ions has been studied.