Factors Affecting Growth and Reproduction in Selected Species of Aphanomyces

Mycologia ◽  
1976 ◽  
Vol 68 (6) ◽  
pp. 1221-1232 ◽  
Author(s):  
Bruce Fowles
1984 ◽  
Vol 35 (2) ◽  
pp. 271 ◽  
Author(s):  
RJ Martin ◽  
JA Carnahan

Plant density and availability of light and water significantly affected growth and reproduction of Noogoora burr plants grown in a glasshouse. Burr yield was reduced most by low levels of available water. Low light intensity, low water availability and high plant density reduced net assimilation rates and, in combination, caused the greatest reduction in burr production. Under field conditions the ratio of burr dry weight to total shoot dry weight decreased with increasing plant density. In terms of production per unit area, dry weight of main stems and main stem leaves increased with increasing plant density at the expense of burr dry weight. We conclude that the success of Noogoora burr as a fleece contaminant could be attributed, in part, to: the insensitivity of burr production to variation in soil fertility and length of growing season; the ability to regulate plant density under conditions of limiting light or water; and the ability to regulate plant components so that the efficiency of burr production increases with a decrease in plant density.


2018 ◽  
Vol 69 (10) ◽  
pp. 1544 ◽  
Author(s):  
Uǧur Karakuş ◽  
Nildeniz Top ◽  
Erdi Gökhan Tepeköy ◽  
John Robert Britton ◽  
Ali Serhan Tarkan

The aim of this study was to provide baseline data and fill an outstanding knowledge gap in our understanding of factors affecting the invasiveness of the Ponto-Caspian gobiid Neogobius fluviatilis. To this end, the life history traits (as somatic growth and reproduction) of N. fluviatilis were studied in three natural freshwater lakes in its native range. These populations were characterised by slow somatic growth rates, being the slowest reported across all the native and non-native ranges of N. fluviatilis. Ages were recorded to 7 years. Across the three lakes, there was considerable variability in sex ratios and reproductive traits (including length at maturity and fecundity at length and age), revealing considerable interpopulation variability. These data suggest that N. fluviatilis has considerable plasticity in the expression of its life history traits, with this plasticity argued as a key factor in facilitating the ability of N. fluviatilis to establish and invade new waters following introductions.


Bioremediation uses microorganisms to destroy or immobilize waste materials. Microorganisms include archaea, bacteria, fungi and actinomycetes. Microorganisms destroy organic contaminants when they are using chemicals for their growth and reproduction. Although it is an old technique, it is still frequently used to remove environmental contaminants which have increased rapidly due to increased population, industrialization, and urbanization. There are various types of bioremediation, and different mechanisms associated with them. The process of bioremediation is enhanced by biostimulation. When bacterial culture is added to the contaminants to increase the rate of biodegradation, it is known as bio augmentation. Biosensors are devices used to detect the presence or concentration of a biological analyse, such as a biomolecule, a biological structure or a microorganism. This paper gives an idea of bioremediation, its scope, factors affecting bioremediation, types, biostimulation, bioaugmentation and biosensors.


Author(s):  
F. A. Heckman ◽  
E. Redman ◽  
J.E. Connolly

In our initial publication on this subject1) we reported results demonstrating that contrast is the most important factor in producing the high image quality required for reliable image analysis. We also listed the factors which enhance contrast in order of the experimentally determined magnitude of their effect. The two most powerful factors affecting image contrast attainable with sheet film are beam intensity and KV. At that time we had only qualitative evidence for the ranking of enhancing factors. Later we carried out the densitometric measurements which led to the results outlined below.Meaningful evaluations of the cause-effect relationships among the considerable number of variables in preparing EM negatives depend on doing things in a systematic way, varying only one parameter at a time. Unless otherwise noted, we adhered to the following procedure evolved during our comprehensive study:Philips EM-300; 30μ objective aperature; magnification 7000- 12000X, exposure time 1 second, anti-contamination device operating.


Author(s):  
Christine M. Dannels ◽  
Christopher Viney

Processing polymers from the liquid crystalline state offers several advantages compared to processing from conventional fluids. These include: better axial strength and stiffness in fibers, better planar orientation in films, lower viscosity during processing, low solidification shrinkage of injection moldings (thermotropic processing), and low thermal expansion coefficients. However, the compressive strength of the solid is disappointing. Previous efforts to improve this property have focussed on synthesizing stiffer molecules. The effect of microstructural scale has been overlooked, even though its relevance to the mechanical and physical properties of more traditional materials is well established. By analogy with the behavior of metals and ceramics, one would expect a fine microstructure (i..e. a high density of orientational defects) to be desirable.Also, because much microstructural detail in liquid crystalline polymers occurs on a scale close to the wavelength of light, light is scattered on passing through these materials.


1990 ◽  
Vol 54 (11) ◽  
pp. 638-643 ◽  
Author(s):  
PC Damiano ◽  
ER Brown ◽  
JD Johnson ◽  
JP Scheetz

1976 ◽  
Vol 7 (4) ◽  
pp. 207-219 ◽  
Author(s):  
Constance P. DesRoches

A statistical review provides analysis of four years of speech therapy services of a suburban school system which can be used for comparison with other school system programs. Included are data on the percentages of the school population enrolled in therapy, the categories of disabilities and the number of children in each category, the sex and grade-level distribution of those in therapy, and shifts in case-load selection. Factors affecting changes in case-load profiles are identified and discussed.


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