Root sclereids ofSyzygium cumini (L.) Skeels

Sclereids in the roots ofSyzygium cumini (L.) Skeels (Myrtaceae) are polymorphic. In addition to the brachy-, osteo- and bizarre sclereids, there occur an interesting kind of sclereids—the fibre sclereids—resembling the fibres in some respects. Sclereids appear only after the onset of secondary activity and fall into one of the following categories depending on their origin: (a) a continuous strand of sclereids in the secondary cortex. This develops from parenchymatous initials that are derivatives of phellogen. Fibre sclereids occur only in this region along with ordinary sclereids and a few fibres. (b) sclereids formed through secondary sclerosis of distal mature parenchyma cells of the dilating phloem rays. (c) Sclereids formed through secondary sclerosis of mature parenchyma cells in old phloem. Sclereids of categoriesb andc a but on those ofa forming a composite strand. All the kinds of sclereids here possess thick, highly lamellated lignified walls with simple and wide pit canals ending in round or oval apertures. The adult sclereids are devoid of nuclei, starch or crystals. Insoluble tannin is present in them except in those formed from phloem parenchyma. Ontogenetical stages of the various kinds of sclereids are similar except that fibre sclereids show a pronounced intrusive growth which although initially bipolar later becomes unipolar. Other kinds of sclereids show either a purely symplastic growth or a combination of various degrees of symplastic and intrusive growth which is either diffuse (some osteosclereids) or multipolar (bizarre sclereids). The inadequacy and unreliability of the existing classifications of and criteria for classifying different mechanical elements particularly in sclereid containing plants are discussed and suggestions made

A chlorophyll-deficiency factor in the natural populations of Tephrosia purpurea (L.) Pers

The selection coefficient for the deficiency allele and the proportion of the two alleles in the populations are estimated. The apparent vegetative and reproductive vigour in the populations with the factor is attributed to the combined effect of low population density caused by the death of the double recessives and the higher selective value of the heterozygotes in these populations. A model of balanced polymorphism involving a recessive lethal is suggested to explain the results. © 1977 Indian Academy of Sciences

Saponins in pollen

Phosphate buffered saline (PBS) extracts of pollen of 34 out of 95 angiosperm species (in 40 families) tested, lysed human and/or snake head fish (Channa striatus Bloch) erythrocytes during assay for lectins in pollen. The bitter taste of the pollen extracts of these 34 species, the formation of a stable foam on shaking and the ability to lyse erythrocytes, suggested the presence of saponins, which have not, so far, been reported from pollen. Thin Layer Chromatography (TLC) and Mass Spectrum (MS) of the erythrocyte-lysing extracts of pollen of the garden gladiolus (Gladiolus gondnvensis Van Hout.) confirmed that the pollen contained both triterpenoidal and steroidal saponins. The implications for the presence of saponins in pollen inhaled from the atmosphere, in the diagnosis and management of pollen allergy arc discussed. © 1993 Taylor and Francis Group, LLC

Hysteresis measurement of anomalous microwave surface resistance in superconducting thin films

The anomalous decrease in microwave surface resistance, R_{s}, of superconducting YBa_{2}Cu_{3}O_{7-d} (YBCO) thin films in the presence of a low dc magnetic field is studied using a microstrip resonator technique. We have done a dc field hysteresis measurement of R_{s} to study the effects of vortex penetration on the anomalous effect. It is shown that the anomaly happens at a field level far below the low critical field, H_{c1,strip}, of the superconducting microstrip and vortex (Abrikosov) penetration would eliminate the anomalous effect observed at low field. This implies that the anomalous effect is not contributed by vortices.Comment: 2 pages, 1 figure, submitted to Physica C for M2S-HTSC-VI Proceeding

A technique for the revival of herbarium specimens for floral dissections and anatomical studies

A tissue softening soln. composed of 20 mL glycerol, 10 mL HOAc, 10 mL 0.292​% aq. soln. EDTA, 10 mL 5​% aq. soln. Na lauryl sulfate, and 50 mL distd. water was used successfully as a softening agent for prepg. herbarium specimens for dissection. No heating is required, and the soln. does not deteriorate on storage or after repeated use. Time required for softening depends on hardness of the tissue; after the desired softness is reached, the tissue can be dissected and retained in the same soln. without risk of drying out or rotting

Saponins and leucoanthocyanins in Cassia L

The distribution of saponins and leucoanthocyanins in 21 species of Cassia and its systematic significance were studied. Quant. and qual. interpopulation variation occurred in saponins. Leucoanthocyanins were absent from herbaceous and semiwoody species of Cassia; they were also absent from yellow-​flowered species. The occurrence of saponins and leucoanthocyanins in Cassia was not correlated

An In vitro comparative evaluation of a hand file and three rotary Nill Instruments for removing gutta percha during root canal re-treatmen

Objective: To evaluate the efficacy of NITI mechanical rotary  instrumentation and Hedstrom file for gutta percha removal using dearing technique.Method: Forty extracted human single rooted premolar, each with a single canal were selected. The samples were decoronated to leave 17 mm root and Instrumented with K-flles upto MAF 30 using step back technique. Samples were obturated using cold lateral condensation of gutta-perdta and AH Plus sealer. The teeth were then randomly divided Into four groups of 10 specimens each. After 2 weeks all the canals were then retreated by either ProTaper re-treatment files, M--two re-treatment files, R-Endo re-treatment flies or Hedstrom flies. The amount of remaining filling materials after re-treatment procedures was assessed by  stereomlcroscope. Also time required for reaching original working length and for removal of obturating material (in min) was measured. Statistical analysis was accomplished using one way Kruskal-Wallls ANOVA and Mann-Whitney U test.Result: M-two re-treatment flies showed least amount of gutta  perdta/sealer followed by Pro Taper re-treatment files, R-Endo  re-treatment flies and Hedstrom files.Conclusion: Under the experimental conditions, significant difference was observed between Pro Taper re-treatment flies&... Hedstrom flies and Mtwo re-treatment flies&... Hedstrom flies for gutta percha/sealer removal. Complete removal of materials did not occur with any of the instrument systems investigated. &nbsp

Supersymmetric solutions of PT-/non-PT-symmetric and non-Hermitian Screened Coulomb potential via Hamiltonian hierarchy inspired variational method

The supersymmetric solutions of PT-symmetric and Hermitian/non-Hermitian forms of quantum systems are obtained by solving the Schrodinger equation for the Exponential-Cosine Screened Coulomb potential. The Hamiltonian hierarchy inspired variational method is used to obtain the approximate energy eigenvalues and corresponding wave functions.Comment: 13 page