Cyclical cell length changes in wood in relation to storied structure and interlocked grain

1979 ◽  
Vol 57 (7) ◽  
pp. 787-794 ◽  
Author(s):  
J. Krawczyszyn ◽  
J. A. Romberger
Keyword(s):  
Cell Length ◽  
Absolute Amount ◽  
Intrusive Growth ◽  
Initial Cell ◽  
Length Increase ◽  
Length Changes ◽  
Nyssa Sylvatica ◽  
Interlocked Grain ◽  
Xylem Fibers ◽  
Fusiform Initial

Interlocked grain can result from migration of a succession of left (S) and right (Z) orientational domains along the cambium. This grain pattern occurs both in species having nonstoried and those having storied cambium. In storied cambia, storey height being fixed, geometry requires that cambial fusiform initial cells undergo cyclical length changes in phase with cyclical inclination changes, e.g., a 4% length increase for a 16° inclination. We can expect the length changes to be detectable in wood if vessel member length reflects fusiform initial cell length and if the absolute amount of intrusive growth during differentiation of fibers is nearly invariant. Measurements of cells from maximum S, maximum Z, and axially aligned grain (I) sites along a radius in Entandrophragma cyclindricum and E. utile wood (storied) revealed clearly cyclical length changes in vessel members, parenchyma strands, and xylem fibers. Measurements in Nyssa sylvatica and Platanus acerifolia (nonstoried) revealed no such changes. Hence in species having storied cambium, cyclical changes in length of wood cells can accompany the slow endogenous rhythm manifested by interlocked grain. This is true because intrusive growth in these species, though extensive, does not obi iterate effects of small differences in cambial initial cell length.

scholarly journals Size variation in the vascular cambium and its derivatives in two Alstonia species

2007 ◽  
Vol 21 (3) ◽  
pp. 531-538 ◽  
Author(s):  
Moin A. Khan ◽  
Badruzzaman Siddiqui
Keyword(s):  
Size Variation ◽  
Tropical Tree Species ◽  
Edaphic Conditions ◽  
Appreciable Increase ◽  
Ray Cells ◽  
Fusiform Initials ◽  
Xylem Ray Cells ◽  
Mother Cells ◽  
Xylem Fibers ◽  
Fusiform Initial

Two tropical tree species viz. Alstonia venenata Br. and Alstonia neriifolia Don. (Apocynaceae) were investigated to detect size variation in different elements of the cambium and its derivative tissues. Although these two species were grown under identical climatic and edaphic conditions, fusiform initial dimensions and the elements derived from them were larger in A. venenata than in A. neriifolia. Ray initials are rectangular in A. venenata but isodiametric in A. neriifolia. An appreciable increase in length was observed in the phloem and xylem ray cells when compared to the mother cells. Maximum elongation was observed in xylem fibers during differentiation from the respective fusiform initials.

scholarly journals In Vivo Outer Hair Cell Length Changes Expose the Active Process in the Cochlea

PLoS ONE ◽  
2012 ◽  
Vol 7 (4) ◽  
pp. e32757 ◽  
Author(s):  
Dingjun Zha ◽  
Fangyi Chen ◽  
Sripriya Ramamoorthy ◽  
Anders Fridberger ◽  
Niloy Choudhury ◽  
...  
Keyword(s):  
Hair Cell ◽  
Outer Hair Cell ◽  
Cell Length ◽  
Active Process ◽  
Length Changes

Outer hair cell length changes in an external electric field. II. The role of electrokinetic forces on the cell surface

1995 ◽  
Vol 98 (4) ◽  
pp. 2011-2017 ◽  
Author(s):  
Rocco A. Jerry ◽  
Aleksander S. Popel ◽  
William E. Brownell
Keyword(s):  
Cell Surface ◽  
Electric Field ◽  
Hair Cell ◽  
External Electric Field ◽  
Outer Hair Cell ◽  
Cell Length ◽  
Length Changes

Apical intrusive growth of cambial fusiform initials along the tangential walls of adjacent fusiform initials: evidence for a new concept

2006 ◽  
Vol 54 (5) ◽  
pp. 493 ◽  
Author(s):  
Joanna Jura ◽  
Paweł Kojs ◽  
Muhammad Iqbal ◽  
Joanna Szymanowska-Pułka ◽  
Wiesław Włoch
Keyword(s):  
Cell Walls ◽  
Tilia Cordata ◽  
Intrusive Growth ◽  
Radial Wall ◽  
Cambial Cell ◽  
Fusiform Initials ◽  
Periclinal Walls ◽  
Symplastic Growth ◽  
Wisteria Floribunda ◽  
Fusiform Initial

A new study of cambium of Pinus sylvestris L., Tilia cordata Mill. and Wisteria floribunda (Willd.) DC provides fresh clues on the cambial dynamics, rejecting the hitherto held concept that intrusive growth of the fusiform initial occurs between the radial walls of adjacent initials. It demonstrates that intrusion of the elongating initial in fact takes place along tangential walls of adjacent fusiform initials and their immediate derivatives. It also suggests a new mechanism for ‘elimination of initials’. Intrusive growth of the fusiform initial was found to begin with development of characteristic slants, representing a transitional stage of the process of transformation of periclinal walls of fusiform initial cells into radial walls, as observed in transverse sections of active cambium. The gradually progressing event comprised (a) appearance of either a triangular microspace limited by two periclinal walls of a fusiform initial and its derivative and one radial wall of another fusiform initial in the adjacent radial file, or a rhomboidal microspace enclosed by four periclinal walls of two laterally adjacent fusiform initials and their immediate derivatives, (b) intrusion of elongating tip of fusiform initial from neighbouring file into the microspace thus formed, (c) symplastic growth of the cambial cell walls in radial direction, (d) unequal periclinal divisions of fusiform initial cells while growing intrusively, and (e) unequal periclinal divisions of derivative cells not growing intrusively. Intrusive growth between periclinal walls affected rearrangement of the fusiform initials but did not add to the cambial circumference. The existing concepts of (a) intrusion of the fusiform initial between radial walls of neighbouring initials and (b) elimination of fusiform initials from cambial surface have been reassessed and redefined.

scholarly journals Expression of smooth muscle myosin light chain 17 and unloaded shortening in single smooth muscle cells

2000 ◽  
Vol 278 (6) ◽  
pp. C1133-C1142 ◽  
Author(s):  
T. J. Eddinger ◽  
A. A. Korwek ◽  
D. P. Meer ◽  
J. J. Sherwood
Keyword(s):  
Smooth Muscle ◽  
Okadaic Acid ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Rabbit Aorta ◽  
Cell Length ◽  
Shortening Velocity ◽  
Protein Ratio ◽  
Initial Cell ◽  
Mrna Ratio

These experiments were performed to test the hypotheses that myosin light chain 17 (MLC17) a and b isoform expression varies between individual vascular smooth muscle (SM) cells and that their expression correlates with cell unloaded shortening velocity. Single SM cells isolated from rabbit aorta and carotid arteries were used to measure unloaded shortening velocity and subsequently were analyzed via RT-PCR for MLC17 a and b mRNA ratio. The MLC17b/a mRNA and protein ratios from adjacent tissue sections correlate very well ( R 2 = 0.68), allowing use of the mRNA ratio to predict the protein ratio. The rabbit MLC17 isoform protein sequence was found to be similar to, but unique from, the swine, mouse, and chicken sequences. Isolated single SM cells from the aorta and carotid have resting lengths of 70–280 μm and shorten to 33–88 μm after contraction. Isolated cell maximum unloaded shortening velocity is highly variable (0.5–7.5 μm/s) but becomes more uniform when normalized to initial cell length (0.01–0.05 cell lengths/s). Carotid cells activated in the presence of okadaic acid (1 μm) have mean maximal unloaded shortening velocities not significantly different from carotid cells activated without okadaic acid (0.016 vs. 0.019 cell lengths/s). Resting cell length before activation is significantly correlated with final cell length after unloaded shortening. Neither initial cell length, final cell length, total cell length change, nor maximum unloaded shortening velocity (absolute or normalized) was significantly correlated with single-cell MLC17b/a mRNA ratio. These studies were performed in isolated single SM cells where unloaded shortening velocity and MLC17b/a mRNA ratios were measured in the same cell. In this preparation, the three-dimensional organization and milieu of the cell is kept intact, but without the intercellular heterogeneity concerns of multicellular preparations. These results suggest the MLC17b/a ratio is variable between individual SM cells from the same tissue, but it is not a determinant of unloaded shortening velocity in single SM cells.

scholarly journals Mechanism of changes in grain inclination in wood produced by storeyed cambium

2015 ◽  
Vol 43 (3) ◽  
pp. 381-398 ◽  
Author(s):  
Z. Hejnowicz ◽  
B. Zagórska-Marek
Keyword(s):  
Cell Orientation ◽  
Fusiform Cell ◽  
Intrusive Growth ◽  
Interlocked Grain

The changes in cell orientation in the cambium of <i>Entandrophragma</i> producing wood with interlocked type of grain, and in the cambium of <i>Tilia</i> in a spirally girdled stem are traced through serial tangential sections of wood. In <i>Entandrophragma</i> the changes result from the intrusive growth of a fusiform cell whih repeatedly produces a new pointed tip from one side of the existing tip which disappears. This causes a sort of creeping of cell ends of one storey past those of the adjoining storey. The oppositely directed ends of the cells belonging to one storey creep in opposite directions so that the position of the cell centres remains constant and only the angle between the cells and the stem axis changes. The stratification of short rays in <i>Entandrophragma</i> represents an adaptation to the changes in celi orientation involved in the formation of interlocked grain. The mechanism of changes in grain inclination in <i>Tilia</i> is intermediate between that based on the creeping of cell ends and that based on pseudotransverse division and intrusive elongation which is known in non-storeyed cambia.

scholarly journals Cell events i n cambium, connected with the formation and existence of a whirled cell arrangement

2015 ◽  
Vol 45 (3) ◽  
pp. 313-326
Author(s):  
Wiesław Włoch
Keyword(s):  
Annual Rings ◽  
Intrusive Growth ◽  
Lateral Edge ◽  
Cell Arrangement ◽  
History Of ◽  
Picea Excelsa ◽  
Fusiform Initial

The history of cambium development was reconstructed on the basis of serial tangential sections of a woody tumour of <i>Picea excelsa</i> (Lam.) Lk. On the area with whirled arragement of the tracheids intrusive growth was found to occur at the lateral radial and longitudinal edges apart from its normal occurrence at the radial apical edges. Intrusive .growth at the radial lateral edge leads to forking of the fusiform initial in the cambium plane. The growth which appears on longitudinal lateral edges oocurs between the tangential walls of cells in neighbouring storeys. In such places a drastic reconstruction of the cell arrangement in neighbouring annual rings was observed. Intrusive growth. between the tangential walls leads to a whirled arrangement of tracheids.

INTERLOCKED GRAIN, CAMBIAL DOMAINS, ENDOGENOUS RHYTHMS, AND TIME RELATIONS, WITH EMPHASIS ON NYSSA SYLVATICA

1980 ◽  
Vol 67 (2) ◽  
pp. 228-236 ◽  
Author(s):  
J. Krawczyszyn ◽  
J. A. Romberger
Keyword(s):  
Endogenous Rhythms ◽  
Nyssa Sylvatica ◽  
Interlocked Grain

Outer hair cell length changes in an external electric field. I. The role of intracellular electro‐osmotically generated pressure gradients

1995 ◽  
Vol 98 (4) ◽  
pp. 2000-2010 ◽  
Author(s):  
Rocco A. Jerry ◽  
Aleksander S. Popel ◽  
William E. Brownell
Keyword(s):  
Electric Field ◽  
Hair Cell ◽  
External Electric Field ◽  
Outer Hair Cell ◽  
Cell Length ◽  
Pressure Gradients ◽  
Length Changes

Ultrasound Assessment of Dorsal Lisfranc Ligament Strain Under Clinically Relevant Loads

2014 ◽  
Vol 104 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Nathan C. Graves ◽  
David D. Rettedal ◽  
Joshua J. Marshall ◽  
Katherine Frush ◽  
Vassilios Vardaxis
Keyword(s):  
Repeated Measures ◽  
Position Effect ◽  
High Stress ◽  
Ligament Length ◽  
Length Increase ◽  
Main Effect ◽  
Lisfranc Ligament ◽  
Significant Length ◽  
Length Changes

Background Pure Lisfranc ligament injuries have a varied clinical presentation, making them difficult to diagnose. This study seeks to understand in vivo strain characteristics of the dorsal Lisfranc ligament under clinically relevant stress loads and foot orientations measured by ultrasound. Methods Randomized ultrasound imaging trials were performed on 50 asymptomatic feet of 20-to-32-year-old individuals who were free of lower-extremity abnormalities. The dorsal Lisfranc ligament was ultrasound imaged under low, medium, and high stress while at 0° and 15° abducted foot orientations. Load was applied using a seated calf-raise apparatus, and a single examiner performed all of the tests. Two-way repeated-measures analysis of variance was used to determine any significant load or position main effects or load × position interaction. Results Position main effect for dorsal Lisfranc ligament length demonstrated a significant overall increase in ligament length of 0.21 mm (P &lt; .001), which reflects a 4.03% change in ligament length between the rectus and 15° abducted orientations. Furthermore, low and medium loads demonstrated significant length increase with position effect (P = .03 and P &lt; .001, respectively). No significant load main effect or interaction was determined. Conclusions Dorsal Lisfranc ligament length undergoes more strain in an abducted foot position at the same load compared with in a rectus foot. We advocate measuring under a medium load if possible and comparing foot positions for the maximum length changes. The participant stress loads and foot positions used are clinically feasible, which makes it possible to perform this ultrasound procedure in the clinical setting.

Sign in / Sign up

Export Citation Format

Share Document