A STUDY ON THE ROLE OF CALCIUM IN XYLEM DEVELOPMENT AND COMPRESSION WOOD FORMATION IN TAXODIUM DISTICHUM SEEDLINGS

IAWA Journal ◽  
2003 ◽  
Vol 24 (1) ◽  
pp. 75-85 ◽  
Author(s):  
Sheng Du ◽  
Fukuju Yamamoto

One-year-old Taxodium distichum seedlings were decapitated and attached to plastic tubing for ‘force feeding’ of liquid media containing different levels of calcium regulating chemicals. The decapitated stems were either vertically placed or tilted at an angle of 45° to be gravitationally stressed. After an eight-week period of culture, diameter growth occurred at 1–3 cm below the cut ends and a large quantity of compression wood cells had differentiated on the lower side of tilted stems that were fed with a modified WPM control medium. However, the application of EGTA, a calcium chelating agent, and LaCl3, a calcium channel blocker, at concentrations of 20 or 50 mM and 1.0 mM, respectively, inhibited the formation of compression wood and the wall thickness of tracheid cells. The results suggested an involvement of calcium in the gravi-stimulated compression wood formation of conifers.

1990 ◽  
Vol 20 (8) ◽  
pp. 1143-1148 ◽  
Author(s):  
Alexander Robertson

Wind is often cited as one of the main causes of compression wood formation. While many papers have alluded to direction of compression wood, this paper provides a detailed circular statistical analysis of the angular distribution of compression-wood zones in balsam fir trees. Discs were sampled from trees in a balsam fir (Abiesbalsamea (L.) Mill.) wave forest in northwestern Newfoundland, from sapling to mature stages. The directionality, with respect to compass bearing, of compression-wood zones in basal discs was found to be initially randomly distributed around the pith, becoming unidirectional towards the northeast at about 10 mm from the pith. Random circular distribution of compression-wood zones mostly within 10 mm of the pith is interpreted as resulting from a combination of environmental perturbations, such as glaze and rain loading, and asymmetric crown growth due to competition. Because of the very high density of immature stands, wind turbulence is not expected to be a major factor stimulating compression wood in saplings. The role of snow loading, which causes bending of stems for long periods during the winter (dormant season), is uncertain. In older trees, i.e., beyond approximately 10 mm from the pith, compression wood gradually becomes directional towards the northeast, indicating that prevailing southwesterly winds are mainly responsible for compression-wood formation.


2010 ◽  
Vol 40 (1) ◽  
pp. 26-36 ◽  
Author(s):  
Barbara Lachenbruch ◽  
Fernando Droppelmann ◽  
Claudio Balocchi ◽  
Miguel Peredo ◽  
Erika Perez

The crooked stems of some individuals of radiata pine ( Pinus radiata D. Don) can hinder volume recovery and wood quality. To infer causes of crookedness and to learn how lean angle affects compression wood (CW) formation we studied 5-year-old trees in southern Chile. Eight initially straight and eight initially crooked trees were tethered initially to angles of 15° or 30° or were left untethered for 131 days (48 trees total). There were no significant differences between straight and crooked trees in the extent of CW in pretreatment wood or in the relationship between stem angle and CW extent. Crooked trees, however, righted themselves more quickly than did straight trees at angles <15°, a result that supports the overcompensation hypothesis for the development of crooked stems. Stem angle had a complex effect on CW extent. In 2- to 3-year-old wood there was no meaningful effect of angle on CW extent. One-year-old wood produced less CW at stem angles <10° than at stem angles >10°, but above or below that threshold, there was no meaningful effect of angle on CW extent. The intertree differences in CW extent, as well as the correlation of leader CW extent with bole CW in the best individuals, suggests that CW assays could be used for early screening for wood quality.


WCET Journal ◽  
2019 ◽  
Vol 39 (2) ◽  
pp. 9-18
Author(s):  
Wai Sze Ho ◽  
Wai Kuen Lee ◽  
Ka Kay Chan ◽  
Choi Ching Fong

Objectives The aim of this study was to retrospectively review the effectiveness of negative pressure wound therapy (NPWT) in sternal wound healing with the use of the validated Bates-Jensen Wound Assessment Tool (BWAT), and explore the role of NPWT over sternal wounds and future treatment pathways. Methods Data was gathered from patients' medical records and the institution's database clinical management system. Seventeen subjects, who had undergone cardiothoracic surgeries and subsequently consulted the wound care team in one year were reviewed. Fourteen of them were included in the analysis. Healing improvement of each sternal wound under continuous NPWT and continuous conventional dressings was studied. In total, 23 continuous NPWT and 13 conventional dressing episodes were analysed with the BWAT. Results Among conventional dressing episodes, sternal wound improvement was 2.5–3% over 10 days to 3.5 weeks, whereas 4–5% sternal healing was achieved in 5 days to 2 weeks with sternal wire presence. Better healing at 11% in 1 week by conventional dressing was attained after sternal wire removal. In NPWT episodes, 8–29%, 13–24%, and 15–46% of healing was observed in 2 weeks, 3.5 to 5 weeks and 6 to 7 weeks, respectively. Only 39% wound healing was acquired at the 13th week of NPWT in one subject. With sternal wire present, 6%–29% wound healing progress was achieved by NPWT in 1–4 weeks, and 16–23% wound improvement in 2 to 4.5 weeks by NWPT after further surgical debridement. After sternal wire removal, 6–34% sternal wound healing occurred by continuous NPWT for 1–2 weeks, and maximum healing at 46% after 2.5 weeks of NPWT were observed. Conclusions Better wound healing was achieved in the NPWT group in comparison to conventional dressings alone. However, suboptimal sternal wound healing by NPWT alone was observed. Removal of sternal wire may improve the effectiveness of NPWT. Successful tertiary closure after NPWT among subjects supports the important bridging role of NPWT in sternal wound healing. Factors causing stagnant sternal wound healing by NPWT alone are discussed.


1968 ◽  
Vol 58 (3) ◽  
pp. 364-376 ◽  
Author(s):  
S. Pesonen ◽  
M. Ikonen ◽  
B-J. Procopé ◽  
A. Saure

ABSTRACT The ovaries of ten patients, at least one year after the post-menopause, were incubated with two Δ5-C19-steroids and also studied histochemically. All these patients had post-menopausal uterine bleeding and increased oestrogen excretion of the urine. The urinary estimations of gonadotrophins, 17-KS, 17-OHCS and pregnanediol were carried out on all patients. Vaginal smears were read according to Papanicolaou, and the endometrium and ovaries were studied histologically. The incubation experiments indicate the presence of Δ5-3β-hydroxysteroid-dehydrogenase. When androst-5-ene-3β,17β-diol was used as precursor the formation of testosterone occurred without any concomitant production of DHA and/or androstenedione. This seems to indicate the possible role of the Δ5-pathway in the formation of testosterone by post-menopausal ovarian tissue. The histochemical reactions indicated a reducing activity on NADH, lactate and glucose-6-phosphate, in certain corpora albicantia, atretic follicles and in diffuse thecoma regions in the cortical layer of the ovary. Steroid-3β-ol-dehydrogenase and β-hydroxybutyrate-dehydrogenase were found only at the edges of certain corpora albicantia, in some individual stroma cell groups and in some atretic follicles. Our studies, both biochemical and histochemical, suggest that the observed increase in the urinary oestrogens of the patients studied might in part at least, be of ovarian origin. This opinion is also supported by the postoperative oestrogen values.


2012 ◽  
Vol 2 (2) ◽  
pp. 345-350
Author(s):  
Dr. Girish.L Dandagi ◽  
◽  
Venkat kalyana kumar. P ◽  
Dr. Dr.Isaac Mathew ◽  
Dr. Dr.G S Gaude Dr. Dr.G S Gaude

Author(s):  
Gulbarshyn Chepurko ◽  
Valerii Pylypenko

The paper examines and compares how the major sociological theories treat axiological issues. Value-driven topics are analysed in view of their relevance to society in times of crisis, when both societal life and the very structure of society undergo dramatic change. Nowadays, social scientists around the world are also witnessing such a change due to the emergence of alternative schools of sociological thought (non-classical, interpretive, postmodern, etc.) and, subsequently, the necessity to revise the paradigms that have been existed in sociology so far. Since the above-mentioned approaches are often used to address value-related issues, building a solid theoretical framework for these studies takes on considerable significance. Furthermore, the paradigm revision has been prompted by technological advances changing all areas of people’s lives, especially social interactions. The global human community, integral in nature, is being formed, and production of human values now matters more than production of things; hence the “expansion” of value-focused perspectives in contemporary sociology. The authors give special attention to collectivities which are higher-order units of the social system. These units are described as well-organised action systems where each individual performs his/her specific role. Just as the role of an individual is distinct from that of the collectivity (because the individual and the collectivity are different as units), so too a distinction is drawn between the value and the norm — because they represent different levels of social relationships. Values are the main connecting element between the society’s cultural system and the social sphere while norms, for the most part, belong to the social system. Values serve primarily to maintain the pattern according to which the society is functioning at a given time; norms are essential to social integration. Apart from being the means of regulating social processes and relationships, norms embody the “principles” that can be applied beyond a particular social system. The authors underline that it is important for Ukrainian sociology to keep abreast of the latest developments in the field of axiology and make good use of those ideas because this is a prerequisite for its successful integration into the global sociological community.


Author(s):  
Admink Admink ◽  
Сергій Виткалов ◽  
Валентина Вігула

Розглядається організаційно-культурна діяльність одного з помітних у регіональному просторі Західного Полісся фотомитця – Олександра Купчинського, а саме виставковий її вектор, втілений в презентації артефактів світового фотомистецтва; видавничий, розглянутий у  контексті  друку  різноманітних  фотоальбомів  із  творів експонентів, організація творчих зустрічей художньої інтелігенції міста з питань обговорення актуальних питань культурного розвитку, заснування фотоклубу тощо. Доводиться, що втрата зв’язку з Батьківщиною, у якій би формі це не відбувалося, не дозволяє митцю творчо самореалізуватися повною мірою. The importance and problematic range of local government reform in the regions of the country and ways of its solution in the field of culture are analyzed. The most effective steps are proposed for management structures at different levels to change attitudes of both the management and the local population regarding different cultural practices. Emphasis is placed on the role of sectoral methodological services in the implementation of this reform. The experience of other countries in activating the local population in this process is emphasized. An attempt has been made to offer effective, in the authors' opinion, solutions to the reform. Emphasis is placed on the educational factor.


2019 ◽  
pp. 58-62
Author(s):  
Vlad Stegariu ◽  
Simona Andreea Popușoi ◽  
Beatrice Abălașei ◽  
Nicolae Lucian Voinea ◽  
Ioan Stelescu ◽  
...  

Chess playing has a significant role in participants’ resources allocation, both at a psychological level, but mostly concerning the cognitive resources. The aim of the present study was to examine the effect of chess playing on the intellectual development of primary-class students. 67 children were tested using the Raven Standard Progressive Matrices and were distributed in three different groups according to their experience with chess, namely: the control group (formed by students with no experience with chess playing), the beginners group (students with less than one year in chess playing training) and the advanced group (children with more than two years experience with chess). Results indicated that chess playing had a significant effect on the SPM performance, indicating that those in the advanced group performed significantly better than those in the control or in the beginners group. Conclusions of this study tap into the benefits of playing chess with a focus on the children’s’ cognitive development.


2020 ◽  
Vol 17 (1) ◽  
pp. 28-37
Author(s):  
Tabinda Sattar

Background: Selenium is a micronutrient, although required in low amounts, its importance in male and female reproduction is well known. Objectives: The core purpose of this study is to evaluate the role of selenium in human reproduction, during pregnancy/ lactation in women and newborns. The review explains side by side the sources of selenium, required amounts of selenium in humans and during pregnancy or lactation. Methods: Selenium deficiency is a major cause of male infertility. Similarly, selenium deficiency, both in pregnant and postpartum women, would greatly affect the health of the newborn baby in all respects. The effect of maternal selenium upon the fetus and the neonates even one year after birth has been explained with some recent examples. Results: The study elaborates the fact that the selenium deficiency in pregnancy and lactation is common due to fetal/infant development, so selenium supplements must be provided in order to overcome these deficiency symptoms. Conclusions: The better reproductive health in humans is possible due to the sufficient amounts of selenium present both in males and females as well.


Author(s):  
Shaun Blanchard

This book sheds further light on the nature of church reform and the roots of the Second Vatican Council (1962–65) through a study of eighteenth-century Catholic reformers who anticipated the Council. The most striking of these examples is the Synod of Pistoia (1786), the high-water mark of late Jansenism. Most of the reforms of the Synod were harshly condemned by Pope Pius VI in the bull Auctorem fidei (1794), and late Jansenism was totally discredited in the ultramontane nineteenth-century Church. Nevertheless, much of the Pistoian agenda—such as an exaltation of the role of bishops, an emphasis on infallibility as a gift to the entire Church, religious liberty, a simpler and more comprehensible liturgy that incorporates the vernacular, and the encouragement of lay Bible reading and Christocentric devotions—was officially promulgated at Vatican II. The career of Bishop Scipione de’ Ricci (1741–1810) and the famous Synod he convened are investigated in detail. The international reception (and rejection) of the Synod sheds light on why these reforms failed, and the criteria of Yves Congar are used to judge the Pistoian Synod as “true or false reform.” This book proves that the Synod was a “ghost” present at Vatican II. The council fathers struggled with, and ultimately enacted, many of the same ideas. This study complexifies the story of the roots of the Council and Pope Benedict XVI’s “hermeneutic of reform,” which seeks to interpret Vatican II as in “continuity and discontinuity on different levels” with past teaching and practice.


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