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Showing papers by "Annamalai University published in 1985"


Journal ArticleDOI
TL;DR: Karyotype analyses were made using root tip mitosis in 21 species of South Indian Apiaceae as mentioned in this paper, and the first record of chromosome numbers have been made in Hydro-cotyle conferta (2n=18), H. candolleana (2 n=18).
Abstract: Karyotype analyses were made using root tip mitosis in 21 species of South Indian Apiaceae. First record of chromosome numbers have been made in Hydro-cotyle conferta (2n=18), H. rotundifolio (2n=18), Pimpinnella pulneyensis (2n=18), P. candolleana (2n=18), Heracleum rigens (2n=40), H. ceylanicum (2n=44), H. sprengelianum (2n=14), H. courtallense (2n=40) H. hookerianum (2n=46), H. aquilegifolium (2n=46), H. candolleanum (2n=40) and H. pedatum (2n=46). The most commonly occurring somatic chromosome number is 2n=18 and 2n=22. It is evident from the present investigation and those data available from earlier studies in this family that aneuploidy and euploidy together with karyotypic asym-metry of chromosomes play important role in the origin and evolution of the species studied.

39 citations


Journal ArticleDOI
TL;DR: In this paper, the natural frequencies of moderately thick transverse isotropic annular sector plates, as obtained by using Mindlin's theory, which includes the effect of shear deformation and rotatory inertia, are presented.

24 citations


Journal ArticleDOI
TL;DR: Fifteen species of Ranunculaceae under eight genera have been studied, mostly collected from different regions of Ooty and Kodaikanal of Western Ghats, and a wide range of chromosome numbers, chromosome sizes and total chromosome lengths of various species studied is shown.
Abstract: Fifteen species of Ranunculaceae under eight genera have been studied, mostly collected from different regions of Ooty and Kodaikanal of Western Ghats. First record of chromosome numbers has been made in Ranunculus wallichianus, R. subpinnatus, R. reniformis, Clematis wightianus, Thalictrum dalzellii and T. saniculaeforme. On the basis of previous and present cytological data, there are n=7 and n=8 series in Ranunculus. All the species of Ranunculus studied here are higher polyploids and both aneuploidy and euploidy play important role in speciation.The previous karyological analyses of Anemone reveal two distinct series, one with n=8 and the other n=7. Both A. rivalaris and A. japonica have 2n=24 chromosomes and they should have derived from n=8 series. Both in the larger size and the same number of chromosomes, Naravelia zeylanica and Clematis wightianus are related together.The presence of fewer number of chromosomes and larger size of them indicates that Nigella damascena is a primitive species. All the three species of Thalictrum, namely T. javanicum, T. dalzellii and T. saniculaeforme possess 2n=16 chromosomes and perhaps, these taxa are diploids derived from n=8 series. The chromosomes are comparatively smaller in size in all these species.Aquilegia canadensis has 2n=32 chromosomes. This may be a polyploid and it should have originated from n=8 basic chromosome series.The population of Delphinium ajacis studied here is a diploid and that of D. belladonna a triploid and the basic chromosome number in Delphinium may be n=8. As far as this genus is concerned, higher polyploidy plays important role in specification.In general, the taxa of Ranunculaceae studied show a wide range of chromo-some numbers from 2n=12 to 2n=46. As most of the taxa studied show either 2n=16 or multiples of n=8, the basic number of the family may be n=8 and the other basic numbers should have derived from it. The species are highly variable and polyphyletic in nature, as evidenced by the wide range of chromosome numbers, chromosome sizes and total chromosome lengths of various species studied.

19 citations


Journal ArticleDOI
TL;DR: A bloom of Hemidiscus hardmannianus in the estuarine and neritic waters of Parangipettai (southern India) was associated with heavy mortality of fishes and invertebrates.
Abstract: A bloom of Hemidiscus hardmannianus (Bacillariophyceae) in the estuarine and neritic waters of Parangipettai (southern India) was associated with heavy mortality of fishes and invertebrates.

18 citations


Journal ArticleDOI
TL;DR: The 13C NMR spectra of several methyl substituted 2,6-diaryl-4-piperidones (aryl = phenyl, o-chlorophenyl) have been measured in this article.
Abstract: The 13C NMR spectra of several methyl substituted 2,6-diaryl-4-piperidones (aryl = phenyl, o-chlorophenyl) have been measured. Substituent parameters for methyl and chloro groups have also been derived and are discussed in terms of their steric and electronic interactions. Both the methyl substitution at C-3 and chlorine substitution in the ortho position of the phenyl ring cause significant changes in the 13C chemical shifts, which can be satisfactorily explained on the basis of steric interactions taking place in the preferred conformations of these molecules. In compounds with o-chloro groups, the aryl ring is oriented such that the chlorine is syn to the axial hydrogen on the aryl-bearing carbon. The shielding effect of the carbonyl group is found to be more pronounced on an adjacent equatorial methyl than on an adjacent axial methyl group.

15 citations


Journal ArticleDOI
TL;DR: A detailed study of the ancient intensity of the Earth's magnetic field in Tamilnadu, India is presented using pottery, bricks, tiles etc., obtained from the excavations that have been carried out at some of the important places of historical and archaeological interest.

12 citations


Journal ArticleDOI
TL;DR: The karyotype analyses show that both genera are characterised by the presence of mostly submetacentric and telocentric chromosomes showing thereby that the two generas are highly evolved but in different lines, eventhough, they might have been originated from a common ancestor.
Abstract: Cytotaxonomical investigation has been made in 21 species of Piper and Peperomia, of which first records of chromosome numbers have been made in Piper attenuatum, P. galeatum, P. schmidtii, P. wightii, P. brachystachum, P. hookeri, Peperomia marmorata and P. rubella.11 is the basic number for Peperomia and 12 for Piper as evidenced by the present investigations. The species of Piper are higher polyploids and aneuploids and the species of Peperomia are mostly aneuploids. The karyotype analyses show that both genera are characterised by the presence of mostly submetacentric and telocentric chromosomes showing thereby that the two genera are highly evolved but in different lines, eventhough, they might have been originated from a common ancestor.

10 citations



Journal ArticleDOI
TL;DR: It is established that under certain conditions a Schur complement in an EP Matrix is as well an EP matrix as well as a partitioned matrix.
Abstract: It is established that under certain conditions a Schur complement in an EP matrix is as well an EP matrix. As an application a decomposition of a partitioned matrix into a sum of EP matrices is given.

8 citations


Journal ArticleDOI
TL;DR: The pattern of changes in (v + V)O 2 closely followed the changes observed in VO 2 rather than vO 2 indicating that the fish held in pesticide medium predominantly relied on aerial respiration.

4 citations