scholarly journals Nest Architecture of the Australian Paper WaspRopalidia Romandi Cabeti, With a Note on its Developmental Process (Hymenoptera: Vespidae)

1994 ◽  
Vol 101 (3-4) ◽  
pp. 145-158 ◽  
Author(s):  
Sôichi Yamane ◽  
Yosiaki Itô
Keyword(s):  
Surface Area ◽  
Cell Walls ◽  
Developmental Process ◽  
Salivary Secretion ◽  
Nest Architecture ◽  
Outer Envelope ◽  
Plant Fibers ◽  
Flat Surfaces ◽  
Irregular Shapes ◽  
Entrance Hole

Nest architecture ofRopalidia romandi cabetiwas described, based on 2 incipient (an active and an abandoned) nests and 3 developed ones. Developed nests were spherical, or hemispherical when built under flat surfaces, consisted of several to more than 10 horizontal combs with oval or irregular shapes. Each comb was suspended by many pedicels from the upper one. Since several combs were simultaneously constructed at the same story, they often produced irregular interconnections that caused complex stair-like, or “semispiral” structures. Combs were entirely surrounded by an outer envelope with a small entrance hole at the lower tip. The envelope was probably constructed after the first group of combs had been completed. Materials for both cells and envelope were plant fibers glued together with salivary secretion. The surface of envelope was more thickly coated with the secretion than cell walls. The largest nest had about 30,000 cells in more than l0 stories of combs that had a surface area of 1,933 cm2. Its dimensions were 21.5 cm in longer diameter and 17.5 cm in height.

scholarly journals Physical basis for the determination of lumen shape in a simple epithelium

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Claudia G. Vasquez ◽  
Vipul T. Vachharajani ◽  
Carlos Garzon-Coral ◽  
Alexander R. Dunn
Keyword(s):  
Developmental Process ◽  
Dominant Role ◽  
Intraluminal Pressure ◽  
Cell Geometry ◽  
Madin Darby Canine Kidney ◽  
Lumen Formation ◽  
Irregular Shapes ◽  
Culture Model ◽  
Darby Canine Kidney

AbstractThe formation of a hollow lumen in a formerly solid mass of cells is a key developmental process whose dysregulation leads to diseases of the kidney and other organs. Hydrostatic pressure has been proposed to drive lumen expansion, a view that is supported by experiments in the mouse blastocyst. However, lumens formed in other tissues adopt irregular shapes with cell apical faces that are bowed inward, suggesting that pressure may not be the dominant contributor to lumen shape in all cases. Here we use live-cell imaging to study the physical mechanism of lumen formation in Madin-Darby Canine Kidney cell spheroids, a canonical cell-culture model for lumenogenesis. We find that in this system, lumen shape reflects basic geometrical considerations tied to the establishment of apico-basal polarity. A physical model incorporating both cell geometry and intraluminal pressure can account for our observations as well as cases in which pressure plays a dominant role.

scholarly journals On the mechanism of rapid plasma membrane and chloroplast envelope expansion in Dunaliella salina exposed to hypoosmotic shock.

1986 ◽  
Vol 102 (1) ◽  
pp. 289-297 ◽  
Author(s):  
M Maeda ◽  
G A Thompson
Keyword(s):  
Plasma Membrane ◽  
Surface Area ◽  
Thin Section ◽  
Dunaliella Salina ◽  
Membrane Surface ◽  
Freeze Fracture ◽  
Chloroplast Envelope ◽  
Outer Envelope ◽  
High Concentration ◽  
Selective Fusion

Dunaliella salina cells rapidly diluted from their normal 1.71 M NaCl-containing growth medium into medium containing 0.86 M NaCl swelled within 2--4 min to an average volume 1.76 X larger and a surface area 1.53 X larger than found in control cells. Morphometric analysis of thin section electron micrographs revealed that certain organelles, including the chloroplast, nucleus, and some types of vacuoles, also expanded in surface area as much or more than did the entire cell. It is likely that glycerol, the most important osmotically active intracellular solute, was present in high concentration within these organelles as well as in the cytoplasm itself. Thin section and freeze-fracture electron microscopy were utilized to trace the origin of membrane material whose addition permitted the large increase in plasma membrane surface area and the equally large growth of the chloroplast outer envelope. The findings indicated that the plasma membrane's expansion resulted from its selective fusion with numerous small (less than or equal to 0.25 micron diam) vesicles prevalent throughout the cytoplasm. In contrast, new membrane added to the chloroplast outer envelope was drawn from an entirely different source, namely, elements of the endoplasmic reticulum.

scholarly journals Bulblet Differentiation after Scale Propagation of Lilium longiflorum

2003 ◽  
Vol 128 (3) ◽  
pp. 324-329 ◽  
Author(s):  
Pablo A. Marinangeli ◽  
Luis F. Hernández ◽  
Cecilia P. Pellegrini ◽  
Néstor R. Curvetto
Keyword(s):  
Developmental Stage ◽  
Surface Area ◽  
Developmental Stages ◽  
Developmental Process ◽  
Rapid Change ◽  
Lilium Longiflorum ◽  
Dry Weight ◽  
Differentiation Process ◽  
Base Width ◽  
The Ideal

External, middle and inner scales in parent bulbs were studied to evaluate bulblet differentiation in Lilium longiflorum Thunb. during scale propagation at 25 °C. A 13-stage developmental process describes different steps including preprimordial, primordial, and bulblet formation. For all scales, preprimordial and primordial stages occurred within the first 4 days. The differentiation process depended on parent scale position. Most bulblets arising from external scales developed three true scales after 30 days while bulblets from middle scales formed four true scales. Homogeneity in the morphology of the parent scales, only shown in the middle ones, was associated with a rapid change in developmental stage for the population of bulblets. Inner scales showed few bulblets with three and four true scales, the rest remaining at earlier developmental stages. Bulblet production decreased from external to internal scales: 2.6, 2.2, and 1.2 bulblets per scale, respectively, and showed a positive correlation with the scale base width. Maximum scale weight and surface area and maximum bulblet fresh and dry weight occurred in the middle scales. We conclude that middle scales are the ideal starting material for experimental uses involving scaling propagation. For production purposes, the external scales, in addition to the middle scales, must also be included for propagation.

Some Ultrastructural Aspects of Vensus’s-Flytrap

1967 ◽  
Vol 25 ◽  
pp. 72-73
Author(s):  
Daniel W. Schwab ◽  
James Scala ◽  
Evelyn B. Simmons
Keyword(s):  
Cell Wall ◽  
Electron Microscope ◽  
Surface Area ◽  
Digestive Gland ◽  
Cell Walls ◽  
Osmium Tetroxide ◽  
Gland Cells ◽  
Dionaea Muscipula ◽  
Usual Manner ◽  
Tubular Inclusions

Recently a study was begun in this laboratory on the insectivorous Venus's-flytrap (Dionaea muscipula Ellis) at all levels of microscopy, with emphasis on ultrastructure. Two features, among others, that stand out in the electron microscope after glutaraldehyde-osmium tetroxide fixation are: (1) a highly-convoluted plasmalemma in the digestive gland cells and (2) a tubular network in the cell walls of the trap lobe.The cell walls and plasmalemma of the digestive gland appear to be highly specialized, in that numerous microvilli-like outgrowths on the walls cause a myriad of invaginations in the plasmalemma (Fig. 1). Thus the plasmalemma has a tremendous surface area which would facilitate its functioning as a secretory and absorptive membrane. Also of interest in the digestive gland are the two distinctly different cell wall inclusions seen in Fig. 2. The bundle of tubular inclusions (Fig. 2, lower half) are apparently specialized plasmodesmata which do not traverse cell walls in the usual manner but run laterally around the cell.

Leafing through Irregular Shapes

2015 ◽  
Vol 21 (1) ◽  
pp. 53-60
Author(s):  
Alessandra King
Keyword(s):  
Middle School ◽  
Middle School Students ◽  
Surface Area ◽  
Three Dimensional ◽  
Real Life ◽  
Two Dimensional ◽  
School Students ◽  
Classroom Experience ◽  
Irregular Shapes ◽  
Area And Volume

By the time middle school students start a prealgebra course, they should have explored a variety of familiar two-dimensional and three-dimensional shapes and should have been exposed to the concepts of perimeter, area, and volume. They know that they can assign numerical values to some attributes of a shape, such as length and surface area. However, my classroom experience confirms the statement that although “students may have developed an initial understanding of area…, many will need additional experiences in measuring directly to deepen their understanding of the area of two-dimensional shapes” (NCTM 2000, p. 242). In addition, the students' previous practice with area is usually with polygons, circles, or a combination of both. However, many real-life objects cannot be described or approximated with simple geometric shapes or with combinations of shapes. Therefore, this activity, which asks students to estimate the area of irregular shapes using finer and finer grids, is not only novel but also a way to apply mathematics to real life.

scholarly journals Nest Architecture and Animals Associated with Neoponera verenae (Forel) (Formicidae, Ponerinae)

Sociobiology ◽  
2021 ◽  
Vol 68 (3) ◽  
pp. e6246
Author(s):  
Hugo Ribeiro Moleiro ◽  
Adolfo Da Silva-Melo ◽  
Edilberto Giannotti
Keyword(s):  
Prey Species ◽  
New Records ◽  
Nest Architecture ◽  
Talcum Powder ◽  
Leaf Cutting ◽  
Entrance Hole ◽  
Associated Species

The nests of ants Neoponera have chambers that can also be occupied by other species of organisms that can be tenants, visitors or prey. However, few studies have considered the assemblage of the associated species and described their composition. This study aimed to describe the architecture and catalog the visitors and prey species found in Neoponera verenae nests. Talcum powder was pumped inside eight nests to mark the chambers and tunnels. The nests were then excavated to describe the architecture and obtain measurements of chambers. The associated species encountered in the nests were collected and identified allowing us to obtain new records of visiting (Linepithema sp., cryptodesmid millipedes and Neotropacarus sp.) and prey taxa (membracids, apid bees and springtails) of N. verenae. Generally, nests had a single entrance hole and a depth of up to 42 cm. Nest chambers were found with three basic forms, elliptical, hangers and boot. Although studies show that this species can occupy abandoned nests of leaf-cutting ants, we found that the nests of N. verenae were more similar to those of Ectatomma ants. Indeed, we found one of the N. verenae nests was attached to a Ectatomma edentatum nest, leading us to suggest that N. verenae may occupy abandoned nests or displace other ants to occupy them.

The leaf anatomy of beech, Fagus grandifolia

1975 ◽  
Vol 53 (19) ◽  
pp. 2202-2211 ◽  
Author(s):  
Nancy G. Dengler ◽  
Lynette B. MacKay
Keyword(s):  
Surface Area ◽  
Cell Walls ◽  
Vascular Tissue ◽  
Leaf Surface ◽  
Mesophyll Cell ◽  
Fagus Grandifolia ◽  
Mesophyll Cells ◽  
Surface Areas ◽  
Leaf Surface Area ◽  
Leaf Volume

Observations have been made on the anatomy of beech, Fagus grandifolia Ehrh., with an emphasis on quantitative features. All surface areas and volumes were determined by projecting 2-μm serial sections, measuring them with a map tracer, and multiplying cell perimeters by section thickness or by the trace–cut–weight method. The organization of tissues, including a complex reticulate venation, is typical of many dicotyledons. Of the minor veins, only the quinternaries and veinlets lack bundle sheath extensions and have wholly parenchymatous bundle sheaths, the cells of which are often oriented at right angles to the vein. There are 12.1 mm of vein per square millimetre of leaf surface area, and 10 μm of vein (the diameter of a mesophyll cell) serves about 21.5 mesophyll cells. The mean maximum distance over which water and solutes must move between vascular tissue and mesophyll is 55 μm. The mesophyll cell walls may provide the pathway through which the bulk of the water moves; the volume occupied by the mesophyll cell walls is 55.7 mm3 or 11% of total leaf volume. The evaporative surface of the mesophyll is 13.36 mm2/mm2 leaf surface area.

Microelectronic Cooling by Enhanced Pool Boiling of a Dielectric Fluorocarbon Liquid

1989 ◽  
Vol 111 (3) ◽  
pp. 752-759 ◽  
Author(s):  
T. M. Anderson ◽  
I. Mudawar
Keyword(s):  
Heat Transfer ◽  
Surface Area ◽  
Atmospheric Pressure ◽  
Initial Conditions ◽  
Nucleate Boiling ◽  
Heat Transfer Surface ◽  
Temperature History ◽  
Surface Geometry ◽  
Flat Surfaces ◽  
Low Profile

An experimental study of boiling heat transfer from a simulated microelectronic component immersed in a stagnant pool of the dielectric Fluorinert (FC-72) is presented. Various enhancement surfaces were attached to an electrically heated copper calorimeter bar having a vertically oriented heat transfer surface area of 12.7×12.7 mm2. A number of enhancement schemes aimed at a reduction of the incipience temperature overshoot were tested, employing various arrangements of fins, studs, grooves, and vapor-trapping cavities. Atmospheric pressure testing revealed a variation in the magnitude of boiling curve incipience temperature excursion as a function of both macro- and microcharacterization of the surface geometry and initial conditions (pressure and temperature history) prior to boiling. Increased incipience temperatures accompanied prolonged periods of nonboiling. It is assumed that this is due to vapor embryos within surface cavities collapsing to smaller radii. Large artificially created cavities (0.3 mm diameter) were found incapable of maintaining a stable vapor embryo for time periods greater than 10 min. In comparison to flat surfaces, low-profile surface geometries having a structure scale of the order of one bubble departure diameter resulted in significant enhancement of nucleate boiling while drilled surfaces had minimal effectiveness. Surface finish and artificial cavities had no effect on CHF, but levels of critical heat flux computed on base area were strongly dependent on macrogeometry, due in part to increased surface area.

The role of cell walls and pectins in cation exchange and surface area of plant roots

2017 ◽  
Vol 215 ◽  
pp. 85-90 ◽  
Author(s):  
A. Szatanik-Kloc ◽  
J. Szerement ◽  
G. Józefaciuk
Keyword(s):  
Cation Exchange ◽  
Surface Area ◽  
Cell Walls ◽  
Plant Roots
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