1,157 research outputs found
The relation of bacteria to nitrification
Citation: Logan, George. The relation of bacteria to nitrification. Senior thesis, Kansas State Agricultural College, 1902.Morse Department of Special CollectionsIntroduction: Very long ago—so far back that the time which has elapsed, even were it capable of being expressed in a definite number of years, would be quite incomprehensible by us—the globe on which we live and which we call the earth, was in a highly heated condition, the intensity of the heat being so great that the materials composing the rocks which we now see around us were in molten condition. In the course of ages much of the earth’s heat was radiated into space; and this went on till at length the earth became sufficiently cooled for some portion of it to assume a solid state. It was probably in this manner that the first hard rock masses made their appearance on the earth’s surface. As the cooling continued, the water vapor, or steam, which must have been present in the hot atmosphere, became condensed into a liquid; the water itself was then subjected to the cooling influence of radiation, and in course of time the earth’s surface became inhabited by low forms of life. The effect of the sun’s heat in those far distant ages would be, as it is now, to cause the water on the earth’s surface to rise in the form of vapor, and so to form clouds. These clouds floating about in the higher atmosphere, would become sufficiently cooled for their water-vapor to be condensed and fall in the form of rain-drops to the earth. And from the amount of water that surrounded the barren earth at that time the evaporation and the condensation must have been intense and thus we have first evidence of wearing away and disintegration of rock
Study of rheumatism in childhood based on a series of cases observed during 30 years of general practice
A Novel Method for Quantifying Spatial Patterns in Plants
Color patterns are found in a plethora of organisms, from vertebrates to flowering plants. While many studies have examined the mechanisms that produce these diverse patterns in animals, little research has investigated the mechanisms by which plants create color patterns. The conclusions drawn from animal studies may not accurately translate to plants due to early divergence in the evolution of life. Characterization of plant patterning mechanisms would have widespread impacts on developmental and evolutionary biology. To unravel the mystery behind pattern formation, we suggest an experimental framework to understand pattern evolution and development at a phenotypic, genotypic, and quantitative level, creating a holistic model for the evolution of complex traits and phenotypic diversity. Here, we provide a novel protocol for the quantification of pattern morphology, and demonstrate its efficacy in a segregating F2 population of the model organism Mimulus luteus . By co-opting ArcGIS and FragStats, two landscape ecology softwares, to map petal patterns, we developed a high throughput method for objective phenotype characterization. This protocol is useful for preliminary work in a bulk segregant analysis by separating a population in discrete groups based on morphology. We used this protocol to demonstrate that patterns are distinct between petals within the same flower depending on petal location, and that there is a genetic basis for pattern formation in flowers. Minor tweaks to the genes guiding pattern formation may be responsible for the rapid evolution of angiosperm flower diversity. Future work is required to identify the genes responsible for pattern formation, and to develop a method for modeling these genes to predict how minor mutations would impact phenotypic traits
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