A survey of cell length and frequency of multiplicative divisions in the cambium of conifers

1970 ◽  
Vol 48 (9) ◽  
pp. 1585-1589 ◽  
Author(s):  
M. W. Bannan
Keyword(s):  
Cell Length ◽  
Annual Rings ◽  
Low Level ◽  
Common Trend ◽  
Anticlinal Division ◽  
Fusiform Initials ◽  
The Common

Study of many species of conifers has revealed certain trends with respect to cell length and rate of anticlinal division in the multiplication of fusiform initials in the cambium. In the stem, rate of anticlinal division tends to be high when annual rings are narrow, and to stabilize at a relatively low level when rings exceed 2 mm in width. Cell length at division is usually greatest when rings are about 1 mm wide, and decreases with both widening and narrowing of the rings from the optimal width. Significant differences occur between species in both rate of anticlinal division and cell length. In general, rate of anticlinal division and cell length are inversely related, but in some species there is wide deviation from the common trend.

CELL SIZE AND SURVIVAL IN CONIFER CAMBIUM

1956 ◽  
Vol 34 (5) ◽  
pp. 769-776 ◽  
Author(s):  
M. W. Bannan ◽  
Isabel L. Bayly
Keyword(s):  
Cell Size ◽  
Tree Growth ◽  
Cell Loss ◽  
Cell Length ◽  
Passing Off ◽  
Anticlinal Division ◽  
Fusiform Initials ◽  
Extensive Cell ◽  
Rate Of Failure ◽  
Selection Of

The pseudotransverse divisions of fusiform initials by which the cambium of conifers is accommodated to increasing girth tend to occur at relatively high rates of frequency. The overproduction of new initials is accompanied by extensive cell loss. The continuation or reduction of fusiform initials after origin in anticlinal division is evidently related to cell length and extent of ray contacts. The largest fusiform initials generally survive and repeat the cycle of elongation and multiplication by pseudotransverse division. The cells of intermediate length continue or fail in varying proportions, the rate of failure tending to rise with increasing frequency of anticlinal division. As a rule the initials with the largest area of ray contacts persist and those with sparse ray contacts decline. The shortest fusiform initials are usually lost, passing off into maturation or undergoing further diminution to ray initials. The continued selection of the longest of the newly formed fusiform initials, which is operative at all stages in tree growth, undoubtedly contributes to the maintenance of an efficient cell length in the secondary vascular tissues.

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.

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.

CAMBIAL BEHAVIOR WITH REFERENCE TO CELL LENGTH AND RING WIDTH IN PINUS STROBUS L.

1962 ◽  
Vol 40 (8) ◽  
pp. 1057-1062 ◽  
Author(s):  
M. W. Bannan
Keyword(s):  
Inverse Relationship ◽  
Ring Width ◽  
Pinus Strobus ◽  
Growth Patterns ◽  
Cell Length ◽  
Annual Rings ◽  
Forest Types ◽  
Thuja Occidentalis ◽  
Cambial Cells ◽  
Individual Trees

The relationships between width of annual rings, length of wood cells, and frequency of anticlinal (multiplicative) divisions in fusiform cambial cells were studied by reference to trees of various growth patterns. The trees selected ranged from 8 to 20 in. diameter and included both open-grown specimens with branches close to the ground and forest types with tall, slender shafts. Much fluctuation was noted among individual trees, but in general there was, in the peripheral growth, an inverse relationship between length of wood cells and width of annual rings. The frequency of anticlinal divisions in the cambium remained at a more or less uniform rate in trees with rings from 1.5 to 5 mm wide, but rose sharply when ring width fell below 1.3 mm. This was in contrast to the situation observed earlier in Thuja occidentalis where the rise in frequency of anticlinal divisions was slight and occurred only in trees with rings less than 0.3 mm wide.

scholarly journals Analyzing the Role of the Permanent and Temporary Shocks in Peru Using the Co-Movements Approach

2021 ◽  
Vol 13 (11) ◽  
pp. 115
Author(s):  
Cesar R. Sobrino
Keyword(s):  
Empirical Work ◽  
Capita Consumption ◽  
Quarterly Data ◽  
Common Trend ◽  
The Common ◽  
Per Capita ◽  
A Minor ◽  
Capita Output ◽  
Per Capita Consumption

In this study, we use the co-movements approach to examine the role of permanent (common trend) and temporary (common cycle) shocks on per capita output, per capita consumption, and per capita investment in Peru, a small open commodity-based economy. Using quarterly data from 1993: Q1 to 2019: Q1, the effects of the temporary shocks are short-lived, and, on average, are a minor source of the variations of macro time series, over 10 quarters. This evidence suggests that the main source of per capita output and per capita consumption variations is the common trend shock which must be related to the 1990s reforms. Moreover, per capita output and per capita consumption are less responsive to unfavorable (favorable) common cycle shocks than per capita investment is. This outcome indicates that per capita investment has a much more volatile cycle than per capita private output and per capita consumption which is consistent with a previous empirical work.

European Grouping of Territorial Cooperation as the instrument of cross border cooperation

2021 ◽  
pp. 60-64
Author(s):  
Yu. Lemko
Keyword(s):  
European Union ◽  
Wastewater Treatment Plants ◽  
Political Support ◽  
Regional Government ◽  
The European Union ◽  
Low Level ◽  
Cross Border ◽  
Non Governmental Organizations ◽  
The Common ◽  
Cross Border Cooperation

The article considers one of the most common and most effective forms of cross-border cooperation between the countries of the European Union, namely the European groupings of territorial cooperation. The role of territorial cooperation in the European Union is constantly growing as it is the basis of political, economic and social cohesion, which is an integral part of Ukrainian society. The development of territorial cooperation is due to the change and development of national, regional or local participants in this process. The Schengen Agreement, the common internal market and the common currency, as well as the emergence of numerous new cross-border projects and the development of cross-border territories, are integral parts of this process. The article examines the EGTC Tisza, which was established in October 2015 in the Transcarpathian region of Ukraine together with the Hungarian region of Szabolcs-Szatmár-Bereg and the municipality of Kisvárd. It is noted that the union has received broad social and political support from both sides at the regional and local levels. This event was decisive for both Ukraine and the EU, as for the first time such an association was created with the participation of a non-EU country. This was a long-awaited step, as the participating regions have long been cooperating together in various fields, including the implementation of grant projects. Many issues need to be addressed together, including flood protection, the rehabilitation of wastewater treatment plants, transport and the development of economic ties. We can say that today Euroregions are the most developed form of cross-border cooperation in Ukraine, but their activities also show a range of problems that hinder their effective functioning. This includes a large number of participants with different cultural and economic characteristics, disparities in the legislation and administration of the country, the low level of business structures and non-governmental organizations. Issues such as the lack of a systematic approach to the organization of Euroregional cooperation, the low level of regional government and the lack of financial support are also worth mentioning.

Coming Out, Going Home

2022 ◽  
pp. 507-519
Author(s):  
Hong-Chi Shiau
Keyword(s):  
Coming Out ◽  
Movement Trajectory ◽  
Social Forces ◽  
Gay Community ◽  
Ethnographic Studies ◽  
Common Trend ◽  
Optimal Distance ◽  
Political Forces ◽  
Spatial Movement ◽  
The Common

Despite the historical centrality of Western cities as sites of queer cultural settlement, larger global economic and political forces have vociferously shaped, dispersed, and altered dreams of mobility for gay Taiwanese millennials in the age of globalization. While Taiwanese gay millennials follow a seemingly universal “rural-to-urban,” “East-to-West” movement trajectory, this study also explicates local nuanced ramifications running against the common trend. Drawn upon five-year ethnographic studies in Taiwan, this study examines how parents could to some extent conform to societal pressures by co-creating a life narrative to the society. Parents/family appear to contribute to how participants' decision on spatial movement but gay male millennials with supportive parents are eventually “going home.” However, the concept of home is configured by multiple economic and social forces involving (1) the optimal distance with the biological family and (2) the proper performances of consumption policed and imposed by the gay community in the neoliberal Taiwanese society.

scholarly journals The common-trend and transitory dynamics in real exchange rate fluctuations

2011 ◽  
Vol 43 (1) ◽  
pp. 1-18 ◽  
Author(s):  
U. Michael Bergman ◽  
Yin-Wong Cheung ◽  
Kon S. Lai
Keyword(s):  
Exchange Rate ◽  
Real Exchange Rate ◽  
Exchange Rate Fluctuations ◽  
Common Trend ◽  
The Common

A Comparative Study on the Current TESL Curriculum: Identifying a Match for Industry Revolution (IR) 4.0

2018 ◽  
Vol 7 (6) ◽  
pp. 214 ◽  
Author(s):  
Faizah Abd Majid
Keyword(s):  
Comparative Study ◽  
English Language ◽  
Language Teachers ◽  
Curriculum Developer ◽  
Policy Makers ◽  
Common Trend ◽  
Core Courses ◽  
English Language Teachers ◽  
The Common ◽  
Programme Outcomes

This paper examines TESL curriculum and how the curriculum relates to the training of the super skills needed in Industry Revolution 4.0 (IR 4.0). Specifically, a comparative study on several TESL programmes offered in several public universities in Malaysia will provide the common trend among the universities and specific strengths of each university. Focus of comparison includes the programme outcomes (PO), discipline core courses offered, methods of delivery and assessment. The comparisons are made to shed some lights on how universities are providing relevant training for the pre-service English language teachers in meeting the demand of Industry Revolution 4.0. In addressing the relevance of the curriculum, a discussion on the super skills needed for IR 4.0, IR characteristics and components will be briefly provided. Findings that address the strengths and rooms for improvement in the current TESL programme curriculum in meeting the need of IR 4.0 could benefit policy makers, curriculum developer and TESL trainers.

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