SPIRAL GRAIN AND ANTICLINAL DIVISIONS IN THE CAMBIUM OF CONIFERS

1966 ◽  
Vol 44 (11) ◽  
pp. 1515-1538 ◽  
Author(s):  
M. W. Bannan
Keyword(s):  
High Ratio ◽  
Contributory Factor ◽  
Relative Duration ◽  
Mature Trees ◽  
Spiral Grain ◽  
Anticlinal Division ◽  
Fusiform Initials ◽  
The Mean ◽  
Cambial Cells ◽  
The Right

In the cambium of mature trees a general conformity was found in the orientation of the partition in the pseudotransverse division of fusiform initials through out sectors of varying size. The proportion of divisions deviating from the preferred orientation varied with the tree, the locality, and the species, but was usually less than 10%. As radial accretion followed, periodic reversals occurred in the orientation of anticlinal divisions, the spacing between reversals, in terms of xylem increment, being related to the frequency of anticlinal division. The mean interval shortened as the rate of division rose according to the equation xy = k. While this overall relationship obtained, there was generally some inequality in the relative duration of leftward and rightward orientations of division. In species with grain in the outer wood slanted to the right, a rightward tilt of division persisted for longer periods than a leftward tilt. Conversely, in species with grain slanted to the left, thickness of xylem showing leftward orientation of multiplicative divisions exceeded that with rightward orientation. Changes associated with growth from sapling to adult were studied in Picea, in which genus grain is usually to the left in the inner wood and to the right in the outer wood. Here multiplicative divisions were usually inclined to the left in the growth of the first few years, whereas in the later growth orientation to the right endured for longer periods than to the left. Both orientation of pseudo-transverse division and direction of cell elongation after division seem to be under a general polar control. This apparently is an important element in the induction of spiral grain. Above-average net gain of fusiform initials in the turmoil of cell addition and loss, which accompanies circumferential expansion, may be a contributory factor. Serving to restrain the development of an excessive spirality are periodic reversals in direction of tilt in anticlinal division, and a high ratio of loss of cambial cells relative to the frequency of anticlinal division.

THE RATE OF ELONGATION OF FUSIFORM INITIALS IN THE CAMBIUM OF PINACEAE

1965 ◽  
Vol 43 (4) ◽  
pp. 429-435 ◽  
Author(s):  
M. W. Bannan
Keyword(s):  
Cell Elongation ◽  
Radial Growth ◽  
Ring Width ◽  
Total Width ◽  
Mature Trees ◽  
Cambial Cell ◽  
Anticlinal Division ◽  
Fusiform Initials ◽  
Wide Ring ◽  
Cambial Cells

This report deals with the rate and amount of elongation of fusiform initials in the cycle of cell elongation and multiplication by pseudotransverse division which accompanies circumferential expansion of the cambium. In the recent growth of mature trees the yearly amount of cambial cell elongation drops as ring width decreases, but not in proportion to the decline in ring width. The cumulative elongation through lineal series of cells, per centimeter of xylem increment, increases as ring width decreases. The amount of cell elongation during the production of several narrow rings greatly exceeds that through a single wide ring having the same total width. It seems clear that the time factor is important in the elongation of cambial cells, and to some extent the interrelated frequency of anticlinal division, particularly when radial growth declines.

RAY CONTACTS AND RATE OF ANTICLINAL DIVISION IN FUSIFORM CAMBIAL CELLS OF SOME PINACEAE

1965 ◽  
Vol 43 (5) ◽  
pp. 487-508 ◽  
Author(s):  
M. W. Bannan
Keyword(s):  
Cell Multiplication ◽  
Cambial Cell ◽  
Intrinsic Factors ◽  
Ray Parenchyma ◽  
Ray Cells ◽  
Anticlinal Division ◽  
Fusiform Initials ◽  
Ray Parenchyma Cells ◽  
Cambial Cells ◽  
Resin Canals

The frequency of pseudotransverse divisions involved in cambial cell multiplication was found to be slightly higher in fusiform initials bordering on fusiform rays than in other cambial cells. The extent of difference was greater in Pinus than in Pseudotsuga or Picea. Because of the larger size of fusiform rays as compared to uniseriate rays, cambial cells adjoining the former were in contact with more ray cells per millimeter of cell length than cambial cells touching only uniseriate rays. As with the frequency of pseudotransverse division, the margin of difference in extent of ray contact was greater in Pinus than in Pseudotsuga or Picea. The evidence therefore indicates that the higher rate of pseudotransverse division in cambial cells adjoining fusiform rays was correlated with the greater area of ray contact, or more specifically, the increased contact with ray parenchyma cells. The higher rate of anticlinal division was apparently the consequence of an increase in ratio of survival of daughter initials arising in pseudotransverse division, some of the smaller newly formed initials persisting in contrast to the usual failure of similar initials situated elsewhere in the cambium. Mean height of uniseriate rays tended to increase with widening of the annual rings, but the size of fusiform rays was influenced to a much smaller degree. The frequency of fusiform rays, and horizontal resin canals, showed no consistent relationship with growth rate, but appeared to be determined by intrinsic factors.

SOME ASPECTS OF THE ELONGATION OF FUSIFORM CAMBIAL CELLS IN THUJA OCCIDENTALS L.

1956 ◽  
Vol 34 (1) ◽  
pp. 175-196 ◽  
Author(s):  
M. W. Bannan
Keyword(s):  
Tip Growth ◽  
Local Environment ◽  
Growth Cycle ◽  
Minor Role ◽  
Mature Trees ◽  
Neighboring Cell ◽  
Fusiform Initials ◽  
Cambial Cells ◽  
A Minor ◽  
High Degree

An outstanding feature of the elongation of fusiform initials is the high degree of variability that exists from cell to cell. This individual inconstancy is to some extent related to recurrent alterations in the local environment. Thus loss of a neighboring cell often results in accelerated elongation. Although frequently masked by the deviations in individual cells, certain general trends of growth become apparent on analysts of the data from numerous cells. In the growth cycle between successive multiplicative divisions the progress of elongation is not uniform but rather follows a familiar growth pattern, early rapid extension giving way to a gradually decreasing rate of elongation as lengthening proceeds. Growth at opposite ends of the same cell is usually dissimilar, basipetal extension tending to predominate. This bipolar difference is evident in the stems of small trees, in the periphery of the stems of mature trees, in the distal parts of branches, and to a lesser degree, in the proximal parts of recurved branches. The reduced bipolar difference in the inverted proximal portions of recurved branches indicates that gravity is not the major factor in the establishment of polarity, but does perhaps play a minor role. Cell elongation is apparently achieved by tip growth.

THE ELONGATION OF FUSIFORM CAMBIAL CELLS IN CHAMAECYPARIS

1950 ◽  
Vol 28c (3) ◽  
pp. 341-355 ◽  
Author(s):  
M. W. Bannan ◽  
Barbara E. Whalley
Keyword(s):  
Secondary Xylem ◽  
Anticlinal Division ◽  
Fusiform Initials ◽  
Cambial Cells ◽  
Symplastic Growth ◽  
And Behavior

Studies of the secondary xylem and phloem indicated that after their origin in anticlinal division, sister fusiform initials usually elongated rapidly, particularly at their overlapping tips. After this first phase, rate and amount of extension varied, both along the overlap and at the opposite ends. Often elongation proceeded in a somewhat periodic fashion, being determined in part by inherent factors and in part by position and behavior of the adjoining cells. Sometimes elongating tips were temporarily stalled at blocking rays, while at other times very rapid extension occurred in association with loss of a neighboring initial from the cambium. Growth appeared to be apical, "intrusive" in the sense that the elongating tips thrust between other cells. No evidence was found to support the theory of simultaneous elongation of considerable portions of adjoining walls by "symplastic" growth.

Cambial Development and Tracheid Length of Dwarf Pines (Pinus Densiflora and P. Thunbergii)

IAWA Journal ◽  
1997 ◽  
Vol 18 (3) ◽  
pp. 301-310 ◽  
Author(s):  
Dong Ok Lim ◽  
Woong Young Soh
Keyword(s):  
Pinus Densiflora ◽  
Annual Rings ◽  
Intrusive Growth ◽  
Tracheid Length ◽  
Naturally Occurring ◽  
Anticlinal Division ◽  
Fusiform Initials ◽  
Cambial Cells ◽  
Mother Cells

From a comparison of cambial cells and their derivatives between naturally occurring dwarf trees and normal ones, it was concluded that tracheids in the annual rings of dwarf trees are shorter, narrower and fewer than those of normal trees. The frequency of anticlinal division and loss of cambial initials is low during differentiation of xylem cells from cambial initials in dwarf pines. The length and intrusive growth of fusiform initials are slightly less than those of normal trees. Thus, it is concluded that the shortening of tracheids in dwarf trees is due to the fact that cambial initials are themselves shortened and that intrusive growth during differentiation of xylem mother cells has occurred.

GIRTH INCREASE IN WHITE CEDAR STEMS OF IRREGULAR FORM

1957 ◽  
Vol 35 (4) ◽  
pp. 425-434 ◽  
Author(s):  
M. W. Bannan
Keyword(s):  
Radial Pressure ◽  
Cell Length ◽  
Vascular Cambium ◽  
White Cedar ◽  
Anticlinal Division ◽  
Fusiform Initials ◽  
Irregular Form ◽  
Cambial Cells

In coniferous stems the rate of multiplication of fusiform initials in the vascular cambium by means of pseudotransverse division often fluctuates considerably around the circumference. In fluted stems the frequency of these divisions is appreciably higher and the ratio of survival of the newly formed initials relative to the rate of production lower in the depressions than in the adjoining convex portions of the perimeter. The probability that compression is a factor tending to accelerate the frequency of anticlinal division is indicated by the decided increase in rate in areas of the stem subjected to radial pressure. Higher frequencies of pseudotransverse division are accompanied by reduction in mean cell length of the cambial cells and hence of the derived wood elements.

THE RELATIVE FREQUENCY OF THE DIFFERENT TYPES OF ANTICLINAL DIVISIONS IN CONIFER CAMBIUM

1957 ◽  
Vol 35 (6) ◽  
pp. 875-884 ◽  
Author(s):  
M. W. Bannan
Keyword(s):  
Relative Frequency ◽  
Small Cells ◽  
Rate Of Growth ◽  
Different Types ◽  
Anticlinal Division ◽  
Fusiform Initials ◽  
Cambial Cells ◽  
Mother Cells ◽  
Ray Initials

The fusiform cambial cells of conifers undergo two types of anticlinal division, pseudotransverse division and division to produce small cells off the side. Pseudotransverse divisions are largely confined to the cambial initials, only a small percentage of such divisions occurring in the derived tissue mother cells. The incidence of pseudotransverse divisions outside the layer of initials tends to rise with the rate of growth. Divisions of the second type, to yield segments off the side, are infrequent and seem generally to involve only the fusiform initials. Behavior of the abscissed segments bears some relationship to size, the shortest segments usually failing, those of intermediate length tending to become reduced to one or more ray initials, and the largest developing as fusiform initials.

DMSA-scintigraphy in paediatrics: Is the evaluation of the geometric mean necessary for the calculation of the differential renal function?

2001 ◽  
Vol 40 (04) ◽  
pp. 107-110 ◽  
Author(s):  
B. Roßmüller ◽  
S. Alalp ◽  
S. Fischer ◽  
S. Dresel ◽  
K. Hahn ◽  
...  
Keyword(s):  
Renal Function ◽  
Geometric Mean ◽  
Region Of Interest ◽  
Posterior View ◽  
Renal Abnormality ◽  
Anterior View ◽  
Differential Renal Function ◽  
The Mean ◽  
The Right ◽  
To Receive

SummaryFor assessment of differential renal function (PF) by means of static renal scintigraphy with Tc-99m-dimer-captosuccinic acid (DMSA) the calculation of the geometric mean of counts from the anterior and posterior view is recommended. Aim of this retrospective study was to find out, if the anterior view is necessary to receive an accurate differential renal function by calculating the geometric mean compared to calculating PF using the counts of the posterior view only. Methods: 164 DMSA-scans of 151 children (86 f, 65 m) aged 16 d to 16 a (4.7 ± 3.9 a) were reviewed. The scans were performed using a dual head gamma camera (Picker Prism 2000 XP, low energy ultra high resolution collimator, matrix 256 x 256,300 kcts/view, Zoom: 1.6-2.0). Background corrected values from both kidneys anterior and posterior were obtained. Using region of interest technique PF was calculated using the counts of the dorsal view and compared with the calculated geometric mean [SQR(Ctsdors x Ctsventr]. Results: The differential function of the right kidney was significantly less when compared to the calculation of the geometric mean (p<0.01). The mean difference between the PFgeom and the PFdors was 1.5 ± 1.4%. A difference > 5% (5.0-9.5%) was obtained in only 6/164 scans (3.7%). Three of 6 patients presented with an underestimated PFdors due to dystopic kidneys on the left side in 2 patients and on the right side in one patient. The other 3 patients with a difference >5% did not show any renal abnormality. Conclusion: The calculation of the PF from the posterior view only will give an underestimated value of the right kidney compared to the calculation of the geometric mean. This effect is not relevant for the calculation of the differntial renal function in orthotopic kidneys, so that in these cases the anterior view is not necesssary. However, geometric mean calculation to obtain reliable values for differential renal function should be applied in cases with an obvious anatomical abnormality.

Therapeutic Effects of Hab Shabyar on Open-Angle Glaucoma: A Double-Blinded, Randomized, Placebo-Controlled Trial

2019 ◽  
Vol 8 ◽  
pp. 1218
Author(s):  
Ebrahim Khalil BaniHabib ◽  
Ali Mostafai ◽  
Seyyed Mohammad Bagher Fazljou ◽  
Ghadir Mohammdi
Keyword(s):  
Placebo Group ◽  
Intraocular Pressure ◽  
Open Angle Glaucoma ◽  
Controlled Trial ◽  
Intervention Group ◽  
Therapeutic Effects ◽  
Open Angle ◽  
The Mean ◽  
The Right ◽  
Double Blinded

Background: Open-angle glaucoma (OAG) is one of the leading causes of blindness worldwide. This study evaluates the therapeutic effects of hab shabyar in patients with open-angle glaucoma. Materials and Methods: In this clinical randomized controlled trial, 50 patients with OAG were randomized into two groups. The intervention group was received a drop of timolol plus 500 mg of hab shabyar every 12 hours. The placebo group was received a drop of timolol every 12 hours plus 500 mg of wheat germ as a placebo. The intraocular pressure in patients with OAG was measured in each group and compared at before the intervention (t1), one month (t2), and two months (t3) after the intervention. Results: The mean decrease in intraocular pressure for the right eye at three times in the intervention group was statistically significant, but the mean decrease in the placebo group was not significant. Similar results were obtained for the left eye at t1 when compared to t3. The patients in the intervention group expressed more satisfaction than the patients in the placebo group (P≤0.001). Conclusion: Our study demonstrated that consumption of timolol plus hab shabyar instead of consuming of timolol alone was probably more effective for reducing intraocular pressure in patients with OAG.[GMJ.2019;In press:e1218]

Flow cytometric identification and isolation of hypertrophic type II pneumocytes after partial pneumonectomy

1989 ◽  
Vol 257 (3) ◽  
pp. C528-C536 ◽  
Author(s):  
B. D. Uhal ◽  
S. R. Rannels ◽  
D. E. Rannels
Keyword(s):  
Gradient Centrifugation ◽  
Type Ii Cells ◽  
Type Ii ◽  
Acridine Orange Staining ◽  
Flow Cytometric ◽  
Percoll Density Gradient Centrifugation ◽  
Type Ii Pneumocytes ◽  
The Mean ◽  
Cellular Dna ◽  
The Right

Type II pneumocytes were isolated by either Percoll density gradient centrifugation or by immunoglobulin G (IgG) panning from the lungs of normal rats and the right lung of rats subjected to left pneumonectomy. Cells were studied at 7- (pnx-7) and 15- (pnx-15) days postoperative, times during and after, respectively, rapid compensatory growth of the right lung. Acridine orange staining permitted resolution of type II cells from contaminants on the basis of high red fluorescence (greater than 590 nm). Simultaneous measurement of forward-angle light scatter (FALS) suggested a shift of pnx-7 cells toward greater size, which was reversed in pnx-15 cells. By Percoll gradient isolation, approximately 15% of pnx-7 cells analyzed were above the mean FALS of control cells. In contrast, approximately 30% of the pnx-7 cells isolated by IgG panning were above the mean FALS of corresponding control cells. Biochemical analyses of pnx-7 cells separated by cell sorting into "high FALS" and "low FALS" subgroups revealed that high FALS type II cells contained 50% more protein (P less than 0.05) and 140% more RNA (P less than 0.01) than low FALS cells, with no significant change in cellular DNA content. These data are consistent with previous studies of type II cells isolated from the lungs of pneumonectomized animals and confirm the presence of hypertrophic cells in these preparations. They provide a foundation from which to design further flow cytometric studies of the role of hypertrophic type II pneumocytes in compensatory lung growth.

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