Vascularisation de la fleur de Spathiphyllum wallisii

1986 ◽  
Vol 64 (7) ◽  
pp. 1397-1401 ◽  
Author(s):  
Denis Barabé ◽  
Louis Chrétien
Keyword(s):  
Central Axis ◽  
Dorsal Bundle ◽  
Ovarian Wall ◽  
Axile Placentation

The hermaphrodite flowers of Spathiphyllum wallisii have six tepals and six extrorse stamens. Gynoecia are either tri- or quadri-locular. In trilocular gynoecia, three dorsal bundles and three complex ventral bundles, each corresponding to the union of two simple ventral bundles belonging to adjacent carpels, are found in the ovarian wall. In the central axis of the ovary, three placental bundles rise to the level of ovular attachment. Each of these splits into two ovular traces. There are two ovules in each locule. When the gynoecium is quadrilocular, four placental bundles, four dorsal bundles, and four complex ventral bundles are usually present. In the flowers of Spathiphyllum wallisii, each carpel is vascularized by a dorsal bundle and by two simple ventral bundles. The path of the placental bundles is typical of that of Araceae with axile placentation.

scholarly journals The Bdkrb2 gene family provides a novel view of viviparity adaptation in Sebastes schlegelii

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jingjing Niu ◽  
Weihao Song ◽  
Rui Li ◽  
Haiyang Yu ◽  
Jian Guan ◽  
...  
Keyword(s):  
Protein Structure ◽  
Vascular System ◽  
Critical Role ◽  
Future Research ◽  
Breeding Cycle ◽  
Exterior Surface ◽  
Black Rockfish ◽  
Vascular Regulation ◽  
Sebastes Schlegelii ◽  
Ovarian Wall

Abstract Background Black rockfish (Sebastes schlegelii) is a viviparous teleost. We proposed that the rockfish ovarian wall had a similar function to the uterus of mammals previously. In the present study, the well-developed vascular system was observed in the ovarian wall and the exterior surface of the egg membrane. In gestation, adaptation of the ovary vasculature to the rising needs of the embryos occurs through both vasodilation and neovascularization. Bdkrb2, encoding a receptor for bradykinin, plays a critical role in the control of vasodilatation by regulating nitric oxide production. Results Eight Bdkrb2 genes were identified in the black rockfish genome. These genes were located on chromosome 14, which are arranged in a tandem array, forming a gene cluster spanning 50 kb. Protein structure prediction, phylogenetic analysis, and transcriptome analysis showed that eight Bdkrb2 genes evolved two kinds of protein structure and three types of tissue expression pattern. Overexpression of two Bdkrb2 genes in zebrafish indicated a role of them in blood vessel formation or remodeling, which is an important procedure for the viviparous rockfish getting prepared for fertilization and embryos implantation. Conclusions Our study characterizes eight Bdrkb2 genes in the black rockfish, which may contribute to preparation for fertilization and embryo implantation. This research provides a novel view of viviparity adaptation and lays the groundwork for future research into vascular regulation of ovarian tissue in the breeding cycle in black rockfish.

scholarly journals EP-1754 High-resolution assessment of dose calculations in small MV photon beams on and off central axis

2019 ◽  
Vol 133 ◽  
pp. S946-S947
Author(s):  
G. Biasi ◽  
N. Hardcastle ◽  
M. Petasecca ◽  
S. Guatelli ◽  
V.L. Perevertaylo ◽  
...  
Keyword(s):  
High Resolution ◽  
Central Axis ◽  
Dose Calculations ◽  
Photon Beams

THE FLAGELLATION, MOVEMENT, AND ENCYSTMENT OF SOME PHYCOMYCETOUS ZOOSPORES

1962 ◽  
Vol 8 (6) ◽  
pp. 897-904 ◽  
Author(s):  
W. E. McKeen
Keyword(s):  
Short Distance ◽  
Pythium Aphanidermatum ◽  
Concave Side ◽  
Central Axis ◽  
Saprolegnia Parasitica ◽  
Anterior Flagellum ◽  
Posterior Flagellum ◽  
Phytophthora Fragariae ◽  
First Time ◽  
The Way

The anterior flagellum of the zoospores of Phytophthora fragariae, P. megasperma, P. cambivora, Saprolegnia parasitica, Achlya americana, and Pythium aphanidermatum projects straight in front of the zoospore and never moves except during encystment whereas the posterior flagellum is active during the swimming period. In the secondary zoospore the anterior and posterior flagella are attached a short distance apart in the center of the depression on the concave side and respectively pass forward and backward through a groove and form a central axis about which the zoospore rotates. Hyaline vesicles which also have been called beads or paddles form at the base of the flagella at the beginning of encystment and glide part or all the way down the flagella. Movement of flagella after they are released from the zoospore is reported for the first time. Encystment may result from contact stimulus except in the case of Allomyces anomalus. A filament on which vesicles may occur may be secreted or retracted by the Allomyces zoospore.

scholarly journals An analysis of diamagnetic levitation away from a suspending magnet’s central axis

AIP Advances ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 085107
Author(s):  
Joe Nhut Ho ◽  
Wei-Chih Wang
Keyword(s):  
Central Axis ◽  
Diamagnetic Levitation

4. Quaternion Investigations connected with Minding's Theorem

1880 ◽  
Vol 10 ◽  
pp. 200-200
Author(s):  
Tait
Keyword(s):  
Rigid Body ◽  
Simple Proof ◽  
Central Axis

AbstractMinding's Theorem deals with what may be called by analogy the “focal lines,” of the system of single resultants of a set of given forces, applied at given points to a rigid body, when these forces are turned about so as to preserve unchanged their inclinations to one another.Having obtained an exceedingly simple proof of the theorem by quaternions, I next tried to find the locus of the foot of the perpendicular let fall on each of these resultants from the “centre of the plane of centres.” The resulting equation is very complex:— but if we extend the data so as to include every position of the central axis (whether there is a couple or no), we arrive at a very simple, and at the same time singular, result.

Quality assurance of central axis dose data for photon beams by means of a functional representation of the tissue phantom ratio

1998 ◽  
Vol 43 (8) ◽  
pp. 2195-2206 ◽  
Author(s):  
Ying Xiao ◽  
Martin D Altschuler ◽  
Bengt E Bjärngard
Keyword(s):  
Quality Assurance ◽  
Central Axis ◽  
Photon Beams ◽  
Tissue Phantom ◽  
Functional Representation

Photophysical Properties of Thermally Activated Delayed Fluorescent Materials upon Distortion of Central Axis of Donor Moiety

2018 ◽  
Vol 122 (50) ◽  
pp. 28576-28587 ◽  
Author(s):  
Hyung Suk Kim ◽  
Hansol Park ◽  
So-Ra Park ◽  
Sang Hoon Lee ◽  
Yunho Ahn ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Central Axis ◽  
Thermally Activated ◽  
Fluorescent Materials ◽  
Donor Moiety

Mr. Ruskin's Lecture on the Savoy Alps

The Geologist ◽  
1863 ◽  
Vol 6 (9) ◽  
pp. 321-327
Keyword(s):  
Central Axis ◽  
Rock Masses ◽  
Mountain Wave ◽  
Organic Life ◽  
Royal Institution ◽  
The Alps ◽  
Physical Phenomena ◽  
Lake Basins

Of Mr. Ruskin's admirable lecture on the Alps of Savoy, delivered at the Royal Institution, we have already given an abstract at p. 256. We recur again to that subject because there were two points so forcibly and so well put by Mr. Ruskin, and so seemingly pregnant with the germs of future progress to our science, as to merit the special attention of geologists. These were the inefficacy of ice to scoop out lake-basins, and the mighty wave-like action of force that crumbles the gigantic rock-masses of our mountains almost into wave-like breakers ready to nod and fall. “Geology,” well remarked Mr. Ruskin in his opening words, “properly divides itself into two branches,—the study, first, of the materials and chronology of deposits; and, secondly, of their present forms.” The interest attaching to the relics of organic life, without doubt, has carried geologists away from the study of external forms; and this almost exclusion of regard for structural phenomena is the more to be regretted that it is the threshold of the grand field of record of ancient physical phenomena. The gigantic mountain-wave is not heaved up and rolled onwards in a few moments, like the surging waves of the sea; the particles of rock-masses are not quickly moved about like the water-atoms of the dancing ripples on our rivers, but slowly—slowly indeed—are the almost immovably linked-together particles forced onwards by some ponderous pressure, some solemn but irresistible force, due perhaps to the very strain of the earth's altering rotation or the leverage of its surface inequalities upon its central axis.

scholarly journals Growing characteristics of apple cultivars and canopies

2015 ◽  
Vol 21 (1-2) ◽  
Author(s):  
Á. Csihon ◽  
I. J. Holb ◽  
I. Gonda
Keyword(s):  
Central Axis ◽  
Slender Spindle ◽  
Apple Cultivars

In our study we aimed to evaluate the growing characteristics of new prospective apple cultivars and their canopies. The following parameters were measured: I) thickness of the trunk and the central leader, II) ratio of the trunk thickness and the basic branches (Zahn indexes), III) number of the branches of the central leader, and iv) thickness of the branches of the central leader. The main branches of the trunk and the central leader tend to over thickening in the case of cvs ‘Red Idared’, ‘Wilton’s Red Jonaprince’ and ‘Jeromine’. The density of the branches of certain parts of the canopy was too low for cvs ‘Crimson Crisp’, ‘Wilton’s Red Jonaprince’, ‘Fuji September Wonder’ and ‘Red Idared’. The density of the branches of certain parts of the canopy was too high for cvs ‘Gala Venus Fengal’, ‘Wilton’s Red Jonaprince’ and ‘Red Cap Valtod’. Relationship was found between the tapering dynamics of the central axis and the thickness of the main branches, which was stronger in super spindle canopies than in slender spindle crown forms.

Sign in / Sign up

Export Citation Format

Share Document