scholarly journals The Role of Root System of Rice Plant in Relation to the Phlysiological and Morphological Characteristics of Aerial Parts : I. Interrelationships of aerial parts and root characteristics in varieties of different plant types

1970 ◽  
Vol 39 (4) ◽  
pp. 487-495
Author(s):  
Yasuo OTA ◽  
Jong Hoon LEE
1990 ◽  
Vol 258 (2) ◽  
pp. L1-L12 ◽  
Author(s):  
A. E. Warner ◽  
J. D. Brain

Pulmonary intravascular macrophages (PIMs) are an extensive population of mature phagocytic cells adherent to the pulmonary capillary endothelium in selected species. They are not prevalent in lungs of commonly studied laboratory animals, such as rodents, and thus have only been recently appreciated. However, their potential role in host defense and acute lung injury has attracted interest, since a number of studies have demonstrated pulmonary localization of circulating particles, microbes, and endotoxin by PIMs. Those animal species, such as ruminants, that provide useful models of pathogen (or endotoxin)-induced acute lung injury demonstrate rapid pulmonary uptake of bacteria by PIMs. Inflammatory mediators released by activated PIMs may initiate the process and provoke accumulation of neutrophils and platelets. This review summarizes the morphological characteristics of PIMs and their species distribution. The role of these members of the mononuclear phagocyte system, both beneficial and potentially pathogenic, is reviewed. The question of whether PIMs have a role in acute lung injury in humans is also discussed.


2012 ◽  
Vol 40 (6) ◽  
pp. 1211-1216 ◽  
Author(s):  
David Emerson

Today high Fe(II) environments are relegated to oxic–anoxic habitats with opposing gradients of O2 and Fe(II); however, during the late Archaean and early Proterozoic eons, atmospheric O2 concentrations were much lower and aqueous Fe(II) concentrations were significantly higher. In current Fe(II)-rich environments, such as hydrothermal vents, mudflats, freshwater wetlands or the rhizosphere, rusty mat-like deposits are common. The presence of abundant biogenic microtubular or filamentous iron oxyhydroxides readily reveals the role of FeOB (iron-oxidizing bacteria) in iron mat formation. Cultivation and cultivation-independent techniques, confirm that FeOB are abundant in these mats. Despite remarkable similarities in morphological characteristics between marine and freshwater FeOB communities, the resident populations of FeOB are phylogenetically distinct, with marine populations related to the class Zetaproteobacteria, whereas freshwater populations are dominated by members of the Gallionallaceae, a family within the Betaproteobacteria. Little is known about the mechanism of how FeOB acquire electrons from Fe(II), although it is assumed that it involves electron transfer from the site of iron oxidation at the cell surface to the cytoplasmic membrane. Comparative genomics between freshwater and marine strains reveals few shared genes, except for a suite of genes that include a class of molybdopterin oxidoreductase that could be involved in iron oxidation via extracellular electron transport. Other genes are implicated as well, and the overall genomic analysis reveals a group of organisms exquisitely adapted for growth on iron.


2014 ◽  
Vol 45 (4) ◽  
pp. 402-405
Author(s):  
Nerida F. Ellerton

Research journals likeJRMEplay key roles through the publication of peerreviewed research, and it is through such publications that the field has the potential to grow. The metaphor of a growing tree is a useful one to explore in the context of mathematics education research. Growth in the natural world is generally multidimensional. A tree's growth is measured not only in terms of its height but also in terms of the girth of its trunk, the spread of its branches, and the development of a substantial root system, all of which are essential for the tree's continued growth and survival. Soil nutrients need to be replenished, and without sufficient moisture, growth is arrested, and the tree becomes stunted. Many of the most interesting natural landscapes include a range of tree species as well as supporting undergrowth.


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