On the petiolar structure of some Asplenium species

1989 ◽  
Vol 67 (1) ◽  
pp. 95-103 ◽  
Author(s):  
P. K. Khare ◽  
Rama Shankar
Keyword(s):  
Transverse Section ◽  
Vascular Strand ◽  
Taxonomic Significance

Petiolar characters of five species of Asplenium, viz., A. cheilosorum, A. dalhousiae, A. laciniatum, A. planicaule, and A. varians, have been investigated and their taxonomic significance is discussed. Petioles in A. varians receive a single vascular strand from the rhizome with two separate xylem strands, which during their upward course, unite to form a single xylem strand. In A. dalhousiae and A. laciniatum each petiole receives two widely separated vascular strands from the rhizome, which remain separate throughout the petiole. In A. cheilosorum and A. planicaule, the two separate vascular strands join each other within the petiole to form a single vascular strand. The shape of xylem strands in a transverse section in all the five species is distinctive.

scholarly journals On the structures and affinities of Ankyropteris corrugata

1930 ◽  
Vol 218 (450-461) ◽  
pp. 79-113 ◽  
Keyword(s):  
Transverse Section ◽  
External Surface ◽  
Vascular Strand ◽  
Coal Measures

Ankyropteris corrugata is a small zygopterid fern found in the calcareous nodules of the Lower Coal Measures of Lancashire and Yorkshire. It was first discovered by Williamson (46, b ), who included it in his comprehensive genus Rachiopteris , giving it the specific name corrugata on account of the fact that the external surface of the stem in his specimen was thrown into a series of irregularly transverse, round-topped ridges. The petioles were also described by him (46, c ) under the name Rachiopteris insignis ; Williamson recognised, however, that the petioles he had described as R. insignis were those of R. corugat , although he never actually published the fact (39). Rachiopteris corrugata was later included in Corda’s genus Zygopteris (15), in common with other palaeozoic ferns, the petioles of which were “characterised by a vascular strand having the form of an H in transverse section” (41). It owes its present generic name to Dr. Paul Bertrand, who, in his important memoir on the petiole-anatomy of the zygopterid ferns (4), has revived, in a limited and more rigidly defined sense, the name employed by Stenzel (42) in his sub-division of Corda’s genus.

Improved 3-D reconstruction using stereo computer graphics and multiple tilt EM images

1995 ◽  
Vol 53 ◽  
pp. 630-631
Author(s):  
Lee D. Peachey ◽  
Lou Fodor ◽  
John C. Haselgrove ◽  
Stanley M. Dunn ◽  
Junqing Huang
Keyword(s):  
Computer Graphics ◽  
High Performance ◽  
Transverse Section ◽  
Three Dimensional ◽  
Stereo Pair ◽  
3D Reconstructions ◽  
Video Cameras ◽  
Biological Objects ◽  
Microscope Images ◽  
High Performance Computer

Stereo pairs of electron microscope images provide valuable visual impressions of the three-dimensional nature of specimens, including biological objects. Beyond this one seeks quantitatively accurate models and measurements of the three dimensional positions and sizes of structures in the specimen. In our laboratory, we have sought to combine high resolution video cameras with high performance computer graphics systems to improve both the ease of building 3D reconstructions and the accuracy of 3D measurements, by using multiple tilt images of the same specimen tilted over a wider range of angles than can be viewed stereoscopically. Ultimately we also wish to automate the reconstruction and measurement process, and have initiated work in that direction.Figure 1 is a stereo pair of 400 kV images from a 1 micrometer thick transverse section of frog skeletal muscle stained with the Golgi stain. This stain selectively increases the density of the transverse tubular network in these muscle cells, and it is this network that we reconstruct in this example.

A microscopic marker experiment study on high temperature oxidation of Ni-Al alloy

1986 ◽  
Vol 44 ◽  
pp. 514-515
Author(s):  
Shou-kong Fan
Keyword(s):  
Transport Mechanism ◽  
High Temperature Oxidation ◽  
Transverse Section ◽  
Al Alloy ◽  
Metal Interface ◽  
Electron Microscopic ◽  
Temperature Oxidation ◽  
Analytical Electron ◽  
Microscopic Studies ◽  
First Time

Transmission and analytical electron microscopic studies of scale microstructures and microscopic marker experiments have been carried out in order to determine the transport mechanism in the oxidation of Ni-Al alloy. According to the classical theory, the oxidation of nickel takes place by transport of Ni cations across the scale forming new oxide at the scale/gas interface. Any markers deposited on the Ni surface are expected to remain at the scale/metal interface after oxidation. This investigation using TEM transverse section techniques and deposited microscopic markers shows a different result,which indicates that a considerable amount of oxygen was transported inward. This is the first time that such fine-scale markers have been coupled with high resolution characterization instruments such as TEM/STEM to provide detailed information about evolution of oxide scale microstructure.

Pharmacognostic studies of Morinda brevipes S. Y. Hu

2019 ◽  
Vol 48 (3) ◽  
pp. 401-407
Author(s):  
Rong Li ◽  
Xiaojing Lin ◽  
Genqiu Tang ◽  
Junni Li ◽  
Dong Wang ◽  
...  
Keyword(s):  
Calcium Oxalate ◽  
Transverse Section ◽  
Volatile Oils ◽  
Needle Crystal ◽  
Cork Cell ◽  
Registration Number ◽  
Phytochemical Studies ◽  
First Time ◽  
Layer Chromatography ◽  
Inequality Type

DNA barcoding of ITS and psbA-trnH regions, histochemistry as well as thin layer chromatography (TLC) of Morinda brevipes S.Y. Hu were analyzed. Transverse section of root revealed the presence of cortex, xylem, cork cell, stone cells, and calcium oxalate sandy crystal. The lower epidermis cells showed many stoma in paracytic or inequality type. Spiral vessel and tiny calcium oxalate needle crystal usually appeared in the powder. TLC showed the presence of emodin in M. brevipes. Phytochemical studies revealed the existence of carbohydrates, saponins, tannins, flavones, anthraquinones, alkaloids and volatile oils. The ITS and psbAtrnH sequences were found for the first time which were submitted to NCBI to obtain the GenBank registration number. This study might play an important role in the identification, and utilization of M. brevipes for various purposes.

A Comparative Pharmacognostical Study of Wild and Cultivate Amalaki (Emblica officinalis Gaertn.)

2018 ◽  
Vol 3 (4) ◽  
Author(s):  
Dr. Shiromani Mishra ◽  
Prof. M. C. Sharma
Keyword(s):  
Transverse Section ◽  
Emblica Officinalis ◽  
Indian Gooseberry ◽  
Wild Variety ◽  
Silica Crystals

Background: Amalaki is traditionally used drug in Ayurveda. Fruits of Amalaki is useful for cure of many disorders. On the basis of Desha Bheda (Habitat) two types of Amalaki are available viz., Gramya Phala (Cultivated) and Vanya Phala (Wild). cultivated variety is more often used as it offers gain to the manufacturers in terms of the amount of pulp available. To differentiate wild and cultivated variety through macroscopic, microscopic and powder microscopy this study was carried out. Objective: Present study was aimed to record comparative macroscopic, microscopic and powder microscopy of wild and cultivated varieties of Indian gooseberry. Methods: Authenticated matured fruits of both varieties were collected and macroscopic and microscopic characters were documented. Result: Fruit of wild variety is smaller and strong astringent than cultivated. In transverse section wild variety shows thick cuticle, lesser engaged area of mesocarp, compactly arranged cells and more concentration of fibres, sclereids and silica crystals than cultivated. Conclusion: Fruit of both varieties differ in size, colour and taste. In transverse section both varieties have same cells with some differentiating characters.

Sign in / Sign up

Export Citation Format

Share Document