There is increasing awareness that human activities are altering the ways that natural systems operate and that local shifts in species composition and abundance can lead to abrupt and irreversible global change. Therefore, understanding the processes that buffer biological communities from critical shifts and how our actions affect natural stabilizing...
This study traces the historical foundations of the concept of
constant ionic proportionality and the equation (Salinity [S%₀] = 1.805
Chlorinity [Cl%₀] + 0.030) which has been in general use in oceanography
since 1902 until 1969 and which is based upon this constancy,
The notion that the constituents present in...
The resurgence of creationism the past few years has been led by advocates
of recent-creationism. These individuals, a minority among creationists in general,
argue that the entire universe was created approximately 10,000 years ago in one six-day
period of time. Recent-creationists support their position by appealing to the
Genesis account...
This analysis concerns the life and scientific work of Henry
Augustus Rowland (1848-1901), organizer and the first chairman of
the physics department at The Johns Hopkins University in 1876.
Special materials used in this research included three pieces of
Rowland's experimental apparatus which are extant in the Smithsonian
Institution Division...
Techniques were developed for extracting histones from isolated
chromatin of encysted embryos of Artemia salina. Histone extracts
from embryos collected at eight time intervals after rehydration and
initiation of development were analyzed by electrophoresis for qualitative
and quantitative changes in composition. Histone to DNA ratios
were determined for the same...
The canyon grasslands of the Hells Canyon National Recreation Area (HCNRA) are a unique ecosystem within the Pacific Northwest Bunchgrass Region (PNWBR) with a long history of natural and anthropogenic disturbances including fire, invasive species introduction, historical livestock grazing, and cultivation. Even with this history, these canyon grasslands contain some...
When sulfur dioxide is used in commercial drying of fruits in
combination with low storage temperatures, browning and microbial spoilage
can be inhibited. However, the relationship between moisture level,
storage temperature, and sulfur dioxide content on the color of dried
fruit is not known; therefore the purpose of this research...
Polyphenol oxidase (PPO) from d'Anjou pears was purified and some
molecular properties were studied. The extraction of PPO was
accomplished in the presence of the phenolic binder AG 2X-8 and Triton
X-100. Chlorophyll pigment was removed by chromatography resulting in
a clear, colorless enzyme extract. Three fractions of pear PPO...
The education (particularly graduate education) of Americans
who were active in astronomical research between 1876 and 1941
is assessed for its effectiveness in preparing the astronomers for
careers in research. This period contains three dynamic changes:
the growth of American astronomy in becoming the world's leading
community of astronomers, the...