Morphology of Dianthoveus cremnophilus (Cyclanthaceae)

1989 ◽  
Vol 67 (8) ◽  
pp. 2450-2464 ◽  
Author(s):  
George J. Wilder
Keyword(s):  
Transition Zone ◽  
Primary Root ◽  
Mirror Image ◽  
Outer Cell ◽  
Wall Ingrowths ◽  
The Third ◽  
Vegetative Buds ◽  
Inflorescence Axis ◽  
Cell Layers

Dianthoveus cremnophilus exhibits terminal inflorescences and rhizomes composed of renewal shoots. A rhizome bears two kinds of vegetative buds directly, viz. renewal buds that form renewal shoots and nonrenewal buds that may develop into new rhizomes. Adult leaves consist of sheath, petiole, transition zone, and a bifid lamina that varies from unicostate to subtricostate. The inflorescence axis consists of peduncle and spadix and bears two kinds of spathes, conspicuous and inconspicuous. Seeds exhibit four outer cell layers and become split periclinally throughout the third layer, as well as longitudinally down to this layer, along one edge. Tissue outside the region of splitting may be abscinded; wall ingrowths of the ruptured third layer adhere to, and appear outermost on, the remaining portion of seed, where they directly contact the environment. Seedlings exhibit a primary root, very short hypocotyl, cotyledon, and epicotyl with plumular leaves. Shoots manifest substantial mirror-image symmetry.

Floral development of Potamogeton densus

1973 ◽  
Vol 51 (3) ◽  
pp. 647-656 ◽  
Author(s):  
U. Posluszny ◽  
R. Sattler
Keyword(s):  
Floral Development ◽  
The Other ◽  
Floral Meristem ◽  
Developmental Sequence ◽  
Initial Activity ◽  
The Third ◽  
Stamen Primordia ◽  
Procambial Strand ◽  
Inflorescence Axis ◽  
Rates Of Growth

The floral appendages of Potamogeton densus are initiated in an acropetal sequence. The first primordia to be seen externally are those of the lateral tepals, though sectioning young floral buds (longitudinally, parallel to the inflorescence axis) reveals initial activity in the region of the lower median (abaxial) tepal and stamen at a time when the floral meristem is not yet clearly demarcated. The lateral (transversal) stamens are initiated simultaneously and unlike the median stamens each arises as two separate primordia. The upper median (adaxial) tepal and stamen develop late in relation to the other floral appendages, and in some specimens are completely absent. Rates of growth of the primordia vary greatly. Though the lower median tepal and stamen are initiated first, they grow slowly up to gynoecial inception, while the upper median tepal appears late in the developmental sequence but grows rapidly, soon overtaking the other tepal primordia. The four gynoecial primordia arise almost simultaneously, although variation in their sequence of inception occurs. The two-layered tunica of the floral apices gives rise to all floral appendages through periclinal divisions in the second layer. The third layer (corpus) is involved as well in the initiation of the stamen primordia. Procambial strands develop acropetally, lagging behind primordial initiation. The lateral stamens though initiating as two primordia each form a single, central procambial strand, which differentiates after growth between the two primordia of the thecae has occurred. A great amount of deviation from the normal tetramerous flower is found, including completely trimerous flowers, trimerous gynoecia with tetramerous perianth and androecium, and organs differentiating partially as tepals and partially as stamens.

scholarly journals Man as Rescuer and Monster in Steven Spielberg's Film Text "Schindler's List"

2008 ◽  
Vol 5 ◽  
pp. 63
Author(s):  
José Díaz-Cuesta Galián
Keyword(s):  
Journal Article ◽  
Mirror Image ◽  
Steven Spielberg ◽  
Religious Traditions ◽  
The Third ◽  
The Bible ◽  
Fold Structure ◽  
Schindler's List ◽  
Film Text

This journal article addresses the confrontation between two extreme representations of man in Steven Spielberg’s Schindler’s List (1993): the rescuer and the monster. It is my contention that these representations simplify two of the moral options –good versus evil– from which men can freely choose according to both Judaism and Catholicism, which are the two religious cults the film alludes to. This article has a three-fold structure. The first part focuses on the godlike representation of Oskar Schindler2 and his relation to key episodes in the Bible. The second one deals with Amon Goeth, Schindler’s mirror image and the incarnation of evil in the film. The third part surveys Spielberg’s blending of religious traditions in some films prior to Schindler’s List. As a conclusion it is proposed that the godlike man who rescues his people is not only Oskar Schindler, but also Steven Spielberg.

scholarly journals Effects of Aluminum and pH on Germination of Echium plantagineum L.

2020 ◽  
Vol 8 (1) ◽  
pp. 313
Author(s):  
Rodrigo Roso ◽  
Ubirajara Russi Nunes ◽  
Caren Alessandra Müller ◽  
Juçara Terezinha Paranhos ◽  
Sidinei José Lopes ◽  
...  
Keyword(s):  
Aerial Part ◽  
Aluminum Sulfate ◽  
Growth Parameters ◽  
Primary Root ◽  
Dry Mass ◽  
The Third ◽  
Sulfate Solutions ◽  
Randomized Design ◽  
Primary Root Length ◽  
Growth Of Seedlings

The objetive of this study was to identify the effects of aluminum concentrations and pH levels of solution on germination of Echium plantagineum L. seeds. Three different experiments were carried out in completely randomized design with four repetitions. In the first experiment, we used aluminum sulfate solutions in concentrations of 0.0; 0.3; 0.6; 1.0; 2.0; 3.0; 4.0; 5.0; 6.0 and 7.0 cmolc L-1 and in the second experiment, solutions with different pH, 3.0; 4.0; 5.0; 6.0; 7.0; 8.0; 9.0 and 10.0. In the third experiment, we carried out a factorial (4x4) with aluminum sulfate solutions (0.0; 2.0; 4.0 and 6.0 cmolc L-1) and pH (4.0; 5.0; 6.0 and 7.0). It was evaluated the germination of Echium plantagineum L. at four and 14 days after seeding (DAS), germination speed index, primary root length, aerial part and dry mass of seedlings. The presence of aluminum reduced the germination by 27 and 40% at four and 14 DAS, respectively, in concentrations superior to 3.0 cmolc L-1. The three growth parameters presented linear reduction with the increase of aluminum concentrations. In the second experiment, the solutions with pH of 3.0 and 10.0 provided increases in germination, length of root and aerial part, and little influence in the dry mass of seedlings. In the third experiment, there was significant interaction between the aluminum concentrations and pH levels of substrate. The presence of aluminum in the substrate presented toxic effect on germination of seeds, length of seedlings and dry mass. The pH of the solution has little effect in germination of seeds and in the growth of seedlings of E. plantagineum.

Control of morphogenetic pathways in thin cell layers of tobacco by pH

1989 ◽  
Vol 67 (3) ◽  
pp. 650-654 ◽  
Author(s):  
A. Cousson ◽  
P. Toubart ◽  
K. Tran Thanh Van
Keyword(s):  
Butyric Acid ◽  
De Novo ◽  
Culture Media ◽  
Callus Formation ◽  
Medium Ph ◽  
Vegetative Buds ◽  
Cell Layers ◽  
Initial Medium ◽  
Vegetative Bud

Thin cell layer explants of tobacco were floated in vitro on the surface of liquid culture media. The initial exogenous concentrations of indolyl-3-butyric acid, and kinetin, the initial medium pH, and the explant density were varied. Various patterns of de novo and direct differentiation without any intermediate callus (flower, vegetative bud, root) as well as the absence of morphogenesis and callus formation without any subsequent organogenesis were separately controlled on 100% of the explants. On the same exogenous combination of glucose, indolyl-3-butyric acid, and kinetin, changes in initial medium pH changed the pattern of morphogenesis. For a given initial exogenous indolyl-3-butyric acid concentration, vegetative buds were obtained at either pH 6.1 or 7.8, whereas a mixture of flowers and vegetative buds was obtained at pH 6.8. Furthermore, changes in explant density changed the morphogenetic response. It is suggested that the effects of the initial medium pH and explant density on morphogenesis may be related partially to modifications of the physicochemical properties of the cell wall and (or) plasmalemma.

Altered Root Structure Affects Both Expression and Cellular Localization of Transporters for Mineral Element Uptake in Rice

2019 ◽  
Vol 61 (3) ◽  
pp. 481-491 ◽  
Author(s):  
En Yu ◽  
Naoki Yamaji ◽  
Jian Feng Ma
Keyword(s):  
Cellular Localization ◽  
Dry Weight ◽  
Mineral Elements ◽  
Outer Cell ◽  
Mineral Element ◽  
Root Structure ◽  
Short Root ◽  
Element Uptake ◽  
Rice Mutant ◽  
Cell Layers

Abstract One of the most important roles of plant roots is to take up mineral elements for their growth. Although several genes involved in root growth have been identified, the association between root structure and mineral element uptake is less investigated. In this study, we isolated a rice mutant (dice1, defective in cell elongation 1) with short-root phenotype. This mutant was characterized by partial defect in the formation of root outer cell layers. Mapping of the responsible gene revealed that the short-root phenotype in the mutant was caused by a single-nucleotide substitution of a gene encoding a membrane-anchored endo-1,4-beta-glucanase (OsGlu3). The growth of both the roots and shoots was partially recovered with increasing strength of nutrient solution and glucose in the mutant. The mutant showed a decreased uptake (normalized by root dry weight) for Mg, Mn, Fe, Cu, Zn, Cd, As and Ge but increased uptake for K and Ca. The expression level of some transporter genes including OsLsi1 and OsLsi2 for Si uptake and OsNramp5 for Mn uptake was significantly decreased in the mutant compared with the wild-type (WT) rice. Furthermore, the cellular localization of OsLsi1 was altered; OsLsi1 localized at the root exodermis of the WT rice was changed to be localized to other cell layers of the mutant roots. However, this localization became normal in the presence of exogenous glucose in the mutant. Our results indicate that a normal root structure is required for maintaining the expression and localization of transporters involved in the mineral element uptake.

Host plant traits associated with resistance of ponderosa pine to the sawfly, Neodiprionfulviceps

1993 ◽  
Vol 23 (5) ◽  
pp. 839-845 ◽  
Author(s):  
Michael R. Wagner ◽  
Zhao-Yi Zhang
Keyword(s):  
Host Plant ◽  
Ponderosa Pine ◽  
Phenotypic Variation ◽  
Plant Traits ◽  
Outer Cell ◽  
Soluble Nitrogen ◽  
Fiber Cells ◽  
Pine Sawfly ◽  
Cell Layers ◽  
Laboratory Bioassays

Phenotypic variation in defoliation of ponderosa pine, Pinusponderosa Laws., by the pine sawfly, Neodiprionfulviceps, is reported. Two field and one laboratory bioassays of paired phenotypically resistant and susceptible trees consistently indicated that sawfly egg, larval, and total survival were 5–14% lower on resistant trees. A suite of host-plant traits were assayed on resistant and susceptible trees including anatomical characteristics of the needles and concentration of terpene and nitrogen. Resistant trees had thicker outer cell layers, more fiber cells, higher toughness, and lower soluble nitrogen than susceptible trees. Resistant and susceptible trees were not distinguished by differences in terpenes. Generational survival of N. fulviceps was inversely related to foliage toughness and number of fiber cells.

Observations of Subcritical Superharmonic and Chaotic Response in Rotordynamics

1992 ◽  
Vol 114 (1) ◽  
pp. 93-100 ◽  
Author(s):  
F. Ehrich
Keyword(s):  
Numerical Model ◽  
Nonlinear System ◽  
Natural Frequency ◽  
Transition Zone ◽  
Chaotic Behavior ◽  
Mirror Image ◽  
Wave Form ◽  
Operating Speed ◽  
Chaotic Response ◽  
Subharmonic Response

When a rotor, excited by unbalance, is operating eccentrically within a clearance and in local contact with the stator it behaves as a bilinear oscillator with a natural periodic motion that resembles bouncing. When excited by unbalance at a subcritical rotative speed which is exactly or nearly 1/Nsuper times its natural frequency, the nonlinear system will respond by bouncing at or nearly at its natural frequency, or superharmonically at a frequency exactly Nsuper times the operating speed or forcing frequency. As in supercritical subharmonic response, there is a zone with characteristics of chaotic behavior in the transition zone between any order of superharmonic response and the next highest order of superharmonic response. There is also an intricate pattern of progressive bifurcations of the orbit on entry into this characteristically chaotic region and a reverse progression on exit from this region. The response is a mirror image or reciprocal set of the more thoughly studied supercritical subharmonic response of the same bilinear oscillator system which, when excited by unbalance at a supercritical rotative speed which is exactly or nearly a whole number Nsub times its natural frequency, the nonlinear system will respond by bouncing at exactly or nearly its natural frequency at a frequency exactly 1/Nsub times the operating speed or forcing frequency. Such supercritical subharmonic response is also characterized by the appearance of characteristically chaotic behavior in the transition zone between successive orders of subharmonic response and by patterns of progressive bifurcations of the orbit on entry into and exit from each region of characteristically chaotic response. Various aspects of subcritical superharmonic response are studied in a numerical model of the nonlinear system, and are compared to data taken on the core spool of an aircraft engine gas turbine. The engine data show many of the unique characteristics of response, wave form, and spectral content predicted by the numerical model of the bilinear oscillator when operating at subcritical rotative speed.

scholarly journals Appearance of myoepithelial cells in developing rat mammary glands identified with the lectins Griffonia simplicifolia-1 and pokeweed mitogen.

1990 ◽  
Vol 38 (11) ◽  
pp. 1647-1657 ◽  
Author(s):  
C M Hughes ◽  
P S Rudland
Keyword(s):  
Epithelial Cells ◽  
Myoepithelial Cell ◽  
Mammary Glands ◽  
Myoepithelial Cells ◽  
Pokeweed Mitogen ◽  
Outer Cell ◽  
Neonatal Rats ◽  
Griffonia Simplicifolia ◽  
Cell Layers ◽  
Developing Rat

The histochemical binding of peroxidase-conjugated Griffonia simplicifolia-1 (GS-1) and pokeweed mitogen (PWM) to methacarn-preserved and paraffin-embedded female rat mammary glands at different developmental stages has been undertaken with a view to investigating the ontogeny of the myoepithelial cell. Conjugated GS-1 fails to stain the outer layer of ductal cells in neonatal rats up to 3 days old, but thereafter the staining increases so that all such cells are intensely stained in rats 5 days old and in mature, pregnant, and lactating rats. Conjugated GS-1 also stains most of the inner epithelial cells that line the ducts in neonatal rats up to about 5 days after birth; thereafter no such cells are stained in mature, pregnant, and lactating rats. Conjugated PWM stains both the inner and outer cell layers of ducts in neonatal rats up to 5 days old; thereafter the fraction of strongly stained cells declines rapidly in both cell layers so that in 6-day-old rats only weak staining is visible. Staining with PWM continues to decline for the inner epithelial cells of the ducts until it ceases when the rats mature; in contrast, that for the outer cell layer of the ducts increases so that all such cells are stained intensely when the rats mature. This pattern of ductal staining with PWM is maintained for pregnant and lactating rats. In terminal end buds of mammary ducts of prepubertal rats, GS-1 binds mainly to the peripheral or cap cells, the staining intensity increasing from cap cells at the distal tip to myoepithelial cells of the subtending duct. PWM binds to many more of the cortical epithelial cells and fewer of the cap cells. At the ultrastructural level, cap cells and adjacent immature myoepithelial cells both bind GS-1 and PWM to their surfaces, but basal clear cells do not. In alveolar buds and in alveoli, both conjugated lectins GS-1 and PWM bind to myoepithelial cells but not to epithelial cells of the rat mammary gland. We suggest that the appearance of carbohydrate receptors for GS-1 and PWM marks specific stages of myoepithelial cell differentiation in developing rat mammary glands.

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