Directionality of compression wood in balsam fir wave forest trees

1990 ◽  
Vol 20 (8) ◽  
pp. 1143-1148 ◽  
Author(s):  
Alexander Robertson
Keyword(s):  
Compression Wood ◽  
Wood Formation ◽  
Balsam Fir ◽  
Forest Trees ◽  
Circular Distribution ◽  
Environmental Perturbations ◽  
Dormant Season ◽  
Snow Loading ◽  
Very High

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.

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
Keyword(s):  
Compression Wood ◽  
Channel Blocker ◽  
Chelating Agent ◽  
Wood Formation ◽  
Taxodium Distichum ◽  
Liquid Media ◽  
Force Feeding ◽  
One Year ◽  
Different Levels

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.

THE ROLE OF GRASSLAND IN MANAGEMENT

1968 ◽  
pp. 44-49
Author(s):  
B.K. Cameron
Keyword(s):  
Soil Temperature ◽  
Annual Rainfall ◽  
Silt Loam ◽  
Average Annual Rainfall ◽  
Very High ◽  
Wilting Point

THE PROPERTY to be discussed is a mixed sheep and cropping unit, situated ei ht a miles east of Ashburton and midway between the Ra aia and the Ashburton rivers. Average annual rainfall is 27 in., evenly spread, but there is very high summer evaporation and therefore frequent droughts. On average, the soil is below wilting point for 40 to 50 days each summer. Winters are cold with the soil temperature being below 48°F for about four months each year. The soil is a Lismore stony silt loam averaging 9 in. in depth over gravel.

Role of Vasavaleha in the management of Covid19

2020 ◽  
Vol 11 (SPL1) ◽  
pp. 259-261
Author(s):  
Aamir Khan ◽  
Rajni K. Gurmule
Keyword(s):  
Immune System ◽  
Human Body ◽  
Respiratory Diseases ◽  
Spreading Rate ◽  
Host Immune System ◽  
Shortness Of Breath ◽  
Antitussive Effect ◽  
Corona Viruses ◽  
Very High

Vasavaleha is one of the best medicine given for respiratory diseases. Corona viruses typically affect the respiratory system, causing symptoms such as coughing, fever and shortness of breath. It also affects host immune system of human body. Spreading rate of this disease is very high. Whole world is seeking for the treatment which can uproots this diseases. There in no vaccine available till date against this pandemic disease. Ayurveda mainly focuses on prevention of diseases alongwith its total cure. Rajyakshma Vyadhi is MadhyamMarga Roga as per Ayurveda. It shows many symptoms such as Kasa, Shwasa etc. By overall view of Covid 19, shows its resemblance with Rajyakshma Vyadhi described in Ayurveda. Vasavaleha is a Kalpa which is described in Rogadhikara of Rajyakshma. It shows Kasahara, Shwashara properties. It consists of Vasa, Pipalli, Madhu and Goghrita. These components shows actions like bronchodilation, antitussive effect and many more other actions. Pipalli shows important Rasayana effect. So in present review, we have tried to focus on role of Vasavaleha in the management of Covid 19. This can be used as preventive as well as adjuvant medication in treating Covid 19. There is need of further clinical research to rule of exact action of Vasavaleha against Covid 19.

Highly sinter-active nanocrystalline RE2O3 (RE = Gd, Eu, Dy) by a combustion process, and role of oxidant-to-fuel ratio in preparing their different crystallographic modifications

2007 ◽  
Vol 22 (3) ◽  
pp. 587-594 ◽  
Author(s):  
V. Bedekar ◽  
S.V. Chavan ◽  
A.K. Tyagi
Keyword(s):  
Combustion Process ◽  
Sintering Behavior ◽  
Stoichiometric Ratio ◽  
Monoclinic Modification ◽  
Fuel Ratio ◽  
Metal Nitrates ◽  
Powder Properties ◽  
Very High ◽  
Scanning Electron

Highly sinter-active powders of RE2O3 [rare earth (RE) = Gd, Eu, Dy] have been prepared using the corresponding metal nitrates as the oxidants, and glycine and citric acid as the fuels. Two different oxidant-to-fuel ratios, namely stoichiometric ratio and fuel-deficient ratio were used to explore the possibility of preparing different crystallographic modifications. By a careful control of oxidant-to-fuel ratio, nanocrystalline Eu2O3 and Gd2O3 could be prepared in cubic (C-type) as well as monoclinic (B-type) modifications. However, the high-temperature monoclinic modification could not be obtained for Dy2O3 due to a very high C-to-B-type phase transition temperature. The crystallite size, surface area, and sintering behavior were also studied for powders prepared using different oxidant-to-fuel ratios, and the results showed a remarkable correlation between different fuel contents and powder properties. Some of these powders resulted in pellets of nearly theoretical density. The sintered microstructure was studied by scanning electron microscopy.

scholarly journals Expanding the breadth of Medicare: learning from Australia

2018 ◽  
Vol 13 (3-4) ◽  
pp. 344-368 ◽  
Author(s):  
Stephen Duckett
Keyword(s):  
Health Care ◽  
Universal Coverage ◽  
Allied Health Professionals ◽  
Australian Health ◽  
Division Of Powers ◽  
Medicare Programme ◽  
High Level ◽  
Very High ◽  
Health Programmes

AbstractThe design of Australia’s Medicare programme was based on the Canadian scheme, adapted somewhat to take account of differences in the constitutional division of powers in the two countries and differences in history. The key elements are very similar: access to hospital services without charge being the core similarity, universal coverage for necessary medical services, albeit with a variable co-payment in Australia, the other. But there are significant differences between the two countries in health programmes – whether or not they are labelled as ‘Medicare’. This paper discusses four areas where Canada could potentially learn from Australia in a positive way. First, Australia has had a national Pharmaceutical Benefits Scheme for almost 70 years. Second, there have been hesitant extensions to Australia’s Medicare to address the increasing prevalence of people with chronic conditions – extensions which include some payments for allied health professionals, ‘care coordination’ payments, and exploration of ‘health care homes’. Third, Australia has a much more extensive system of support for older people to live in their homes or to move into supported residential care. Fourth, Australia has gone further in driving efficiency in the hospital sector than has Canada. Finally, the paper examines aspects of the Australian health care system that Canada should avoid, including the very high level of out-of-pocket costs, and the role of private acute inpatient provision.

The Role of Ectomycorrhizal Symbiosis in the Resistance of Forests to Water Stress

2000 ◽  
Vol 29 (1) ◽  
pp. 63-69 ◽  
Author(s):  
Jean Garbaye
Keyword(s):  
Water Stress ◽  
Sustainable Management ◽  
Fine Roots ◽  
Forest Ecosystems ◽  
Water Status ◽  
Forest Trees ◽  
Direct Effects ◽  
Ectomycorrhizal Symbiosis ◽  
Protection Mechanisms

Forest trees live in enforced symbiosis with specialized fungi that form composite organs (ectomycorrhizas) with fine roots. This paper examines how this association contributes to the water status of trees and how it plays a major role in the protection mechanisms by which trees and forest stands resist drought-induced water stress. It shows how ectomycorrhizal symbiosis has both direct effects (at the uptake level) and indirect effects (at the regulation level) on the water status of trees. The facts presented are discussed in terms of forest adaptation to changing environmental conditions and the practical consequences for the sustainable management of forest ecosystems.

scholarly journals Metallic Nanoparticles Obtained via “Green” Synthesis as a Platform for Biosensor Construction

2019 ◽  
Vol 9 (4) ◽  
pp. 720 ◽  
Author(s):  
Galina Gayda ◽  
Olha Demkiv ◽  
Nataliya Stasyuk ◽  
Roman Serkiz ◽  
Maksym Lootsik ◽  
...  
Keyword(s):  
Green Synthesis ◽  
Metallic Nanoparticles ◽  
Alcohol Oxidase ◽  
Inorganic Ions ◽  
Special Role ◽  
Graphite Electrodes ◽  
Fluorescent Markers ◽  
Extracellular Metabolites ◽  
Very High

Novel nanomaterials, including metallic nanoparticles obtained via green synthesis (gNPs), have a great potential for application in biotechnology, industry and medicine. The special role of gNPs is related to antibacterial agents, fluorescent markers and carriers for drug delivery. However, application of gNPs for construction of amperometric biosensors (ABSs) is not well documented. The aim of the current research was to study potential advantages of using gNPs in biosensorics. The extracellular metabolites of the yeast Ogataea polymorpha were used as reducing agents for obtaining gNPs from the corresponding inorganic ions. Several gNPs were synthesized, characterized and tested as enzyme carriers on the surface of graphite electrodes (GEs). The most effective were Pd-based gNPs (gPdNPs), and these were studied further and applied for construction of laccase- and alcohol oxidase (AO)-based ABSs. AO/GE, AO-gPdNPs/GE, laccase/GE and laccase-gPdNPs/GE were obtained, and their analytical characteristics were studied. Both gPdNPs-modified ABSs were found to have broader linear ranges and higher storage stabilities than control electrodes, although they are less sensitive toward corresponding substrates. We thus conclude that gPdNPs may be promising for construction of ABSs for enzymes with very high affinities to their substrates.

The economic and financial viability of sheltered employment centres

2019 ◽  
Vol 57 (9) ◽  
pp. 2261-2283
Author(s):  
Vera Gelashvili ◽  
Eva María Aguilar Pastor ◽  
María-Jesús Segovia-Vargas ◽  
Maria-del-Mar Camacho-Miñano
Keyword(s):  
Training Programs ◽  
Similar Response ◽  
Economic Returns ◽  
Content Type ◽  
Strategic Plans ◽  
Low Levels ◽  
The Difference ◽  
Practical Implications ◽  
Very High

Purpose The purpose of this paper is to investigate whether sheltered employment centers (CEEs) which have a higher rate of professionalization of their managers have better economic returns than those that have a lower one. Design/methodology/approach A questionnaire has been drawn up for their managers. After collecting the answers, an index of professionalization classifies the CEEs with managers of high, medium and low levels of professionalism. This index is then correlated with the main financial ratios of companies. Findings The results show that companies with the highest level of managers’ professionalization, on average, have higher economic returns than companies with medium and low rates, although the difference is not very high. This study is an important contribution to academic literature, as it is the first to examine the professionalization of CEE managers. Research limitations/implications Finally, this paper is not short of limitations. The number of responses is small but there are similar studies with similar response rates. Additionally, the scarcity of responses may suggest that there is a lack of interest about the utility of professionalization by some CEEs managers because, perhaps, they do not have the necessary competences to understand its importance in management. Practical implications This study has some main implications for stakeholders: first, CEEs must pay more attention to the professionalization of their management team, because professionalization can lead to meeting its goals and guaranteeing the firm’s growth. Second, training programs in skills and attitudes should be designed to strengthen these competencies. Moreover, managers of social firms should know that the establishment of strategic plans will be useful to identify new opportunities in the market. Social implications Given the important role of these social firms for the employment of people with disabilities, training programs should be promoted by government in order to ensure the professionalization of these companies. Originality/value This research is an important contribution to the literature on this subject because there are no studies about the level of professionalization of CEEs, companies that represent an important value for the economy of a country.

The stability of onoratoite, Sb8O11Cl2, in the supergene environment

2014 ◽  
Vol 78 (7) ◽  
pp. 1671-1675 ◽  
Author(s):  
Adam J. Roper ◽  
Peter Leverett ◽  
Timothy D. Murphy ◽  
Peter A. Williams
Keyword(s):  
Significant Influence ◽  
Secondary Phase ◽  
Low Ph ◽  
Stable Phase ◽  
Supergene Zone ◽  
A Value ◽  
Solubility Studies ◽  
The Stability ◽  
Very High

AbstractSynthesis and solubility studies of onoratoite have been undertaken to determine the role of this rare secondary phase in the immobilization of Sb and the conditions responsible for its formation in the supergene zone. Solubility studies were undertaken at 298.15 K. A value of ΔGfθ (Sb8O11Cl2, s, 298.15 K) = –2576 ±12 kJ mol–1 was derived. Calculations involving sénarmontite, Sb2O3, klebelsbergite, Sb4O4SO4(OH)2 and schafarzikite, FeSb2O4, show that onoratoite is a thermodynamically stable phase only at negligible activities of SO42–(aq) and low activities of Fe2+(aq), at low pH and very high activities of Cl–(aq). This explains why onoratoite is such a rare secondary phase and why it cannot exert any significant influence on the dispersion of Sb in the supergene environment.

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