Anatomical aspects of the taxonomy of sedges (Carex, Cyperaceae)

1990 ◽  
Vol 68 (7) ◽  
pp. 1449-1456 ◽  
Author(s):  
L. A. Standley
Keyword(s):  
Cluster Algorithm ◽  
Single Layer ◽  
Epidermal Cells ◽  
Primitive Character ◽  
Bulliform Cells ◽  
Group Criterion ◽  
Phylogenetic Studies ◽  
As Species ◽  
Anatomical Characters ◽  
The Common

Patterns of variation in the anatomy of achene epidermis and leaves were examined to assess the utility of anatomical characters in systematic and phylogenetic studies of Carex and the Cyperaceae. This study was based primarily on a review of the available literature. In addition, foliar anatomy of species in Carex sect. Phacocystis was investigated and patterns of variation within the section were analyzed using a centroid cluster algorithm. Nearly all genera and all sections of Carex for which data are available include species with single conical silica bodies in the achene epidermal cells as well as species with more elaborate, presumably derived, silica bodies. Similarly, most sections within Carex include species that have hypostomatous leaves with a single layer of bulliform cells and that lack papillae, as well as species with amphistomatous leaves, papillose epidermal cells, or multiple bulliform cells. Application of the "common equals primitive" in group criterion for determining evolutionary polarity indicates that single conical silica bodies and epapillose hypostomatous leaves are primitive character states in Carex. As both primitive and derived character states are widely distributed among sections, anatomical characters should not be generally applied as measures of similarity in phenetic approaches to classification but have potentially major importance in phylogenetic studies within and among sections.

scholarly journals Tropical forages: morphoanatomy of plants grown in areas with the death of pasture syndrome

2017 ◽  
Vol 77 (4) ◽  
pp. 868-875
Author(s):  
N. G. Ribeiro-Júnior ◽  
O. S. Fagundes ◽  
A. S. Benevenuti ◽  
O. M. Yamashita ◽  
A. A. B. Rossi ◽  
...  
Keyword(s):  
Nutritional Quality ◽  
Epidermal Cells ◽  
Point Of View ◽  
Panicum Maximum ◽  
Vascular Cylinder ◽  
Bulliform Cells ◽  
Leaf Mesophyll ◽  
Cynodon Nlemfuensis ◽  
Urochloa Brizantha ◽  
Sclerenchyma Fibers

Abstract Roots and leaves of Panicum maximum Tanzânia, Mombaça and Massai; Urochloa brizantha Piatã, Marandu and Xaraés; Urochloa humidicola Llanero; Urochloa ruziziensis Ruzizienses; Urochloa hybrida Mulato II and Cynodon nlemfuensis Estrela-roxa were analyzed, seeking to identify characters for better adaptation to the environment that may interfere with digestibility of tissue from the point of view of the rumen in cattle. Were planted ten cultivars in a completely randomized blocks with three repetitions. Was collected vegetative material, which histological slides were prepared from middle third of the sections of roots and leaves. Were observed differences (p>0.05) in the roots: higher volume of epidermal cells (28.62 µm) and overall diameter (1926.41 µm) of Llanero; thicker vascular cylinder (975.09 µm) and more protoxylem (42.25) in Estrela-roxa and occurrence of aerenchyma in cultivars Piatã, Mulato II, Xaraés, Massai, Llanero and Estrela-roxa; Were found higher proportions of bulliform cells in the leaves (121.07 µm) and thicker leaf mesophyll in U. humidicola Llanero (263.63 µm); higher proportion of sclerenchyma fibers in Xaraés and Marandu; lower results for amount of fibers in P. maximum Massai. We conclude that the cultivars Estrela-roxa, Llanero and Massai have greater adaptability to the environment and better nutritional quality.

Design and Implementation of QCA D-Flip-Flops and RAM Cell Using Majority Gates

2019 ◽  
Vol 28 (05) ◽  
pp. 1950079 ◽  
Author(s):  
Trailokya Nath Sasamal ◽  
Ashutosh Kumar Singh ◽  
Umesh Ghanekar
Keyword(s):  
Circuit Design ◽  
High Speed ◽  
High Performance ◽  
Single Layer ◽  
Memory Cell ◽  
Design Parameters ◽  
Flip Flop ◽  
Negative Edge ◽  
Wire Crossing ◽  
The Common

Quantum-dot cellular automata (QCA) is one of the promising technologies that enable nanoscale circuit design with high performance and low-power consumption features. As memory cell and flip-flops are rudimentary for most of the digital circuits, having a high speed, and a less complex memory cell is significantly important. This paper presents novel architecture of D flip-flops and memory cell using a recently proposed five-input majority gate in QCA technology and simulated by QCADesigner tool version 2.0.3. The simulation results show that the proposed D flip-flops and the memory cell are more superior to the existing designs by considering the common design parameters. The proposed RAM cell spreads over an area of 0.12[Formula: see text][Formula: see text]m2and delay of 1.5 clock cycles. The proposed level-triggered, positive/negative edge-triggered, and dual edge-triggered D flip-flop uses 14%, 33%, and 21% less area, whereas the latency is 40%, 27%, and 25% less when compared to the previous best design. In addition, all the proposed designs are implemented in a single layer QCA and do not require any single or multilayer wire crossing.

scholarly journals Marrying molecules and morphology: first steps towards a reevaluation of solariellid genera (Gastropoda: Trochoidea) in the light of molecular phylogenetic studies

2020 ◽  
Vol 86 (1) ◽  
pp. 1-26
Author(s):  
S T Williams ◽  
Y Kano ◽  
A Warén ◽  
D G Herbert
Keyword(s):  
Type Species ◽  
Morphological Characters ◽  
Shell Shape ◽  
Molecular Systematic ◽  
The Past ◽  
Phylogenetic Studies ◽  
Clade B ◽  
The Family ◽  
Molecular Phylogenetic ◽  
Anatomical Characters

ABSTRACT The assignment of species to the vetigastropod genus Solariella Wood, 1842, and therefore the family Solariellidae Powell, 1951, is complicated by the fact that the type species (Solariella maculata Wood, 1842) is a fossil described from the Upper Pliocene. Assignment of species to genera has proved difficult in the past, and the type genus has sometimes acted as a ‘wastebasket’ for species that cannot easily be referred to another genus. In the light of a new systematic framework provided by two recent publications presenting the first molecular phylogenetic data for the group, we reassess the shell characters that are most useful for delimiting genera. Shell characters were previously thought to be of limited taxonomic value above the species level, but this is far from the case. Although overall shell shape is not a reliable character, our work shows that shell characters, along with radular and anatomical characters, are useful for assigning species to genera. Sculpture of the early teleoconch (the region immediately following the protoconch) and the columella are particularly useful characters that have not been used regularly in the past to distinguish genera. However, even with the combination of all morphological characters used in this study (shell, radular and eye), a few species are still difficult to assign to genera and in such cases molecular systematic data are essential. In the present study, we discuss 13 genera—12 of which were recovered as well-supported clades in recent molecular systematic studies—and provide morphological characters to distinguish them. We describe several new taxa: Chonospeira n. gen. (referred to as ‘clade B’ in previous molecular systematic studies), Phragmomphalina n. gen. (Bathymophila in part in molecular systematic studies) and Phragmomphalina vilvensi n. sp. (type species of Phragmomphalina n. gen.). We synonymize Hazuregyra Shikama, 1962 with Minolia A. Adams, 1860, Minolia subangulata Kuroda & Habe, 1952 with Minolia punctata A. Adams, 1860 and M. gemmulata Kuroda & Habe, 1971 with M. shimajiriensis (MacNeil, 1960). We also present the following new combinations: Bathymophila bairdii (Dall, 1889), B. dawsoni (Marshall, 1979), B. regalis (Marshall, 1999), B. wanganellica (Marshall, 1999), B. ziczac (Kuroda & Habe in Kuroda, Habe & Oyama, 1971), Chonospeira nuda (Dall, 1896), C. iridescens (Habe, 1961), C. ostreion (Vilvens, 2009), C. strobilos (Vilvens, 2009), Elaphriella corona (Lee & Wu, 2001), E. diplax (Marshall, 1999), E. meridiana (Marshall, 1999), E. olivaceostrigata (Schepman, 1908), E. opalina (Shikama & Hayashi, 1977), Ilanga norfolkensis (Marshall, 1999), I. ptykte (Vilvens, 2009), I. zaccaloides (Vilvens, 2009), Minolia shimajiriensis (MacNeil, 1960), M. watanabei (Shikama, 1962), Phragmomphalina alabida (Marshall, 1979), P. diadema (Marshall, 1999), P. tenuiseptum (Marshall, 1999), Spectamen euteium (Vilvens, 2009), S. basilicum (Marshall, 1999), S. exiguum (Marshall, 1999) and S. flavidum (Marshall, 1999).

Floral anatomy of the Milla complex genera (Themidaceae)

2010 ◽  
Vol 87 ◽  
pp. 1
Author(s):  
Sofía Loza-Cornejo ◽  
Fernando Chiang Cabrera ◽  
Eduardo Ruiz-Sanchez ◽  
José Luis Villaseñor ◽  
Mario Ernesto Suárez-Mota ◽  
...  
Keyword(s):  
Floral Anatomy ◽  
Epidermal Cells ◽  
The Other ◽  
Floral Tube ◽  
Floral Buds ◽  
Parenchyma Cells ◽  
Anatomical Characters

Floral morpho-anatomy of the Milla complex genera (Themidaceae) was studied with the aim to confirm the occurrence of a gynophore in Dandya, to determine if there are anatomical characters that allow to distinguish Dandya from the rest of genera of the complex (Behria, Bessera, Jaimehintonia, Milla, and Petronymphe), and to understand their evolution. Floral buds of ten species of the Milla complex were studied through the standard paraffin microtechnique. The results demonstrated the presence of a gynophore without pith in Dandya, while the other genera have a gynophore with pith. In addition, Dandya differs from the other genera of the complex by a closed-stigma with external papillae, nectary cavities of horned-shape with tabular epidermal cells, and filaments with 4-strata of parenchyma cells. Behria and Bessera share characters such as connated stamens and an ovary with the external epidermis papillose. Attributes like gynophore with pith, percentage of adnnation between ovary and floral tube of 20-30%, stigma with an open ending, and nectary cavities with discoidal shape are probably ancestral conditions in the Milla complex, from which transformation of character states occurred mostly in Dandya.

Systematic implications of achene micromorphology in Carex section Hymenochlaenae (Cyperaceae)

1990 ◽  
Vol 68 (3) ◽  
pp. 630-639 ◽  
Author(s):  
Marcia J. Waterway
Keyword(s):  
Epidermal Cells ◽  
Evolutionary Relationships ◽  
Character State ◽  
Primitive Character ◽  
Modified Silica ◽  
Surface Features ◽  
Parallel Development ◽  
Wall Structures ◽  
Epidermal Features

The structures of the achene epidermal cells and their included silica deposits are illustrated and described for 28 species that have been referred to Carex section Hymenochlaenae. On the basis of these epidermal features, there are anomalous species in nearly all of the subsections and sections that have been circumscribed by Kükenthal, Mackenzie, Ohwi, and Koyama. Furthermore, some species with nearly indistinguishable achene surface features have quite different overall morphologies and have traditionally been placed in different sections. Similarities in the structure of the silica deposits in the achene epidermal cells may result from the retention of the primitive character state in several different lineages or from parallel development of modified silica bodies or wall structures in different lineages. Levels of homoplasy appear to be too high to make these characters reliable indicators of evolutionary relationships in Carex section Hymenochlaenae.

The Metamorphosis of Insects: Tercentenary Lecture delivered by Professor V. B. Wigglesworth, F. R. S., at 10.15 a.m. on Saturday 23 July 1960 at the Royal College of Surgeons

1961 ◽  
Vol 16 (1) ◽  
pp. 81-84 ◽  
Keyword(s):  
Epidermal Cell ◽  
Royal College ◽  
Single Layer ◽  
Secretory Activity ◽  
Epidermal Cells ◽  
Social Functions ◽  
Outer Skin ◽  
The Subject ◽  
Growth Changes

THE visible form of the insect is defined by the outer skin or cuticle. The cuticle is the product of the single layer of epidermal cells which lie beneath it. The form of the insect is thus determined by the growth changes and the secretory activity of the epidermal cell. The purpose of the lecture was to approach the subject of metamorphosis through a consideration of the physiology of the epidermal cell. The epidermal cell is interesting because it combines within itself so many functions, actual and potential; social functions as a member of the community of cells of which it forms a part, and individual functions where it is concerned primarily with its own affairs.

The distribution and significance of enamel and enameloid in the dermal skeleton of osteolepiform rhipidistian fishes

Paleobiology ◽  
1983 ◽  
Vol 9 (2) ◽  
pp. 138-149 ◽  
Author(s):  
Deborah K. Meinke ◽  
Keith Stewart Thomson
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Regulatory Change ◽  
Primitive Character ◽  
Developmental History ◽  
Phylogenetic Studies ◽  
Morphological Criteria ◽  
History Of ◽  
Dermal Bones ◽  
Scanning Electron

Teeth and other dermal skeletal elements from three osteolepid and two eusthenopterid rhipidistians were examined with the scanning electron microscope to establish whether the hypermineralized outer layer was enameloid or enamel. Using Smith's (1978) morphological criteria to infer the developmental history of enamel and enameloid, enamel was found in the teeth and dermal bones of the osteolepids, whereas enameloid was identified in scales. Hyneria and Eusthenopteron teeth also had enamel. As enamel has also been found in teeth of living lungfishes and extant Latimeria, the presence of enamel in tetrapod teeth represents a primitive character retained from a lobe-finned ancestor and is not useful for phylogenetic studies within the lobe-finned/tetrapod group. Shellis and Miles' (1974) hypothesis that the transition from enameloid to enamel occurred via a fairly simple regulatory change is discussed.

The structure of the antennal heart of Aedes aegypti (Linnaeus)

1997 ◽  
Vol 75 (3) ◽  
pp. 444-458 ◽  
Author(s):  
B. D. Sun ◽  
J. M. Schmidt
Keyword(s):  
Electron Microscopy ◽  
Connective Tissue ◽  
Aedes Aegypti ◽  
Light And Electron Microscopy ◽  
Single Layer ◽  
Epidermal Cells ◽  
Muscle Fibres ◽  
Columnar Cells

The structure of the antennal heart of Aedes aegypti (L.) (Diptera: Culicidae) was observed using light and electron microscopy. The antennal heart consists of several distinct regions including a single layer of columnar cells, the chamber walls, the valve, the z-body, the muscle fibres, and the connective tissue filaments. The columnar cells are structurally similar to secretory and osmoregulatory cells. Features of tendinous epidermal cells typically involved in the attachment of muscles to the cuticle can be observed in various areas of the antennal heart when it is examined as a whole. A model describing the pumping mechanism of the antennal heart in A. aegypti is presented.

A silicified semiaquatic dicotyledon from the Eocene Allenby Formation of British Columbia

1973 ◽  
Vol 51 (7) ◽  
pp. 1373-1377 ◽  
Author(s):  
Coleman R. Robison ◽  
Christopher P. Person
Keyword(s):  
British Columbia ◽  
Adventitious Roots ◽  
Single Layer ◽  
Salient Feature ◽  
Anatomical Structure ◽  
Main Axis ◽  
Epidermal Cells ◽  
Coal Basin ◽  
Lateral Branches ◽  
Air Cavities

A silicified dicotyledon rhizome is described from the Eocene Allenby Formation of the Princeton Coal Basin, British Columbia. The primary and secondary vascular tissues of the rhizome form a narrow cylinder around a broad, parenchymatous pith. The rhizome's salient feature is a wide cortex in which there are numerous air cavities. In most specimens the cortex is surrounded by a single layer of epidermal cells but in some there is evidence of periderm initiation. Small lateral branches are borne on the main axis, and both the main and lateral axes bear broad, clasping leaf bases and adventitious roots. The affinities of this rhizome are presently unknown, but its anatomical structure is indicative of a semiaquatic plant.

scholarly journals 2D Gain Enhancement Based on Single-Layer SIW Corrugated Technique with Slot Array Feeder

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Mingtuan Lin ◽  
Chenglong Lin
Keyword(s):  
Reflection Coefficient ◽  
Printed Circuit Board ◽  
Single Layer ◽  
High Gain ◽  
Circuit Board ◽  
Design Complexity ◽  
Printed Circuit ◽  
Gain Enhancement ◽  
High Gain Antenna ◽  
The Common

Novel slot-array-based SIW corrugated technique is demonstrated to achieve 2D gain enhancement, namely, sharpening the beamwidths in both E-plane and H-plane. Compared to other metallic corrugated methods to realize 2D gain enhancement, the proposed design, with SIW grooves to reduce the beamwidth in E-plane and slot array to increase the directivity in H-plane, has a lower profile, weight, and design complexity, which can be easily fabricated with the common printed circuit board (PCB) technique. A prototype is designed and fabricated, with measurement presenting a low reflection coefficient less than −10 dB from 26.4 GHz to 28.2 GHz and an enhanced gain up to 18 dB. Overall, our proposed technique will be beneficial for the design of high-gain antenna in 5G wireless terminals.

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