The objectives of this research were to isolate and
determine the molecular structures of certain polyphenols
in Douglas-fir and red alder barks. The compounds of
interest in Douglas-fir were the lignans which are
eventually incorporated into the outer bark phlobaphenes.
Phlobaphenes are the red colored, alcohol soluble, water
insoluble phenolic...
The most active phenolics in Quercus sideroxyla Humb. & Bonpl. residual bark were identified and evaluated following a chromatographic fractionation. Bark powder was defatted with hexane and crude extract (CE) was obtained by extraction with aqueous acetone (70%). A liquid partition with ethyl acetate was performed to produce an organic...
Using techniques that permit the direct observation of
fetuses in vivo, prenatal behavioral development was
compared among four species in the rodent family Muridae:
the Norway rat (Rattus norvegicus), Mongolian gerbil
(Meriones unguiculatus), cotton rat (Sigmodon hispidus), and
spiny mouse (Acomys cahirinus). Rattus and Meriones bear
altricial offspring, as do...
The respiratory and metabolic biology of dinosaurs is poorly, if at all, reflected in the fossil record. By comparing anatomical features of modern taxa that are functionally linked to specific biology with the remains of theropod dinosaurs (Archosauria: Theropoda) and early birds, we may reasonably infer the physiology of long...
Until the 1930s, flows of the Colorado River maintained approximately 781,060 hectares of wetlands in its delta. These wetlands provided important feeding and nesting grounds for resident and migratory birds as well as spawning and protection habitat for many fish and other invertebrate species. However, the Delta's wetlands started to...
Changes in blood calcium and phosphorus concentrations were
characterized for rainbow trout (Salmo gairdneri) and coho salmon
(Oncorhynchus kisutch) following intense exercise or exposure to
suspended volcanic ash or topsoil. Significant elevations in blood
calcium and phosphorus accompanied exercise-induced acidemia in both
S. qairdneri and O. kisutch. These elevations persisted...
Inferences regarding the biology of extinct taxa are often founded primarily
on cladistically-based phylogenetic hypotheses. However, these inferences are
frequently inconsistent with the morphology and physiology of modern animals. I
suggest that reference to the biology of modern animals might be a more
appropriate tool to aid in the reconstruction...
Using an oral history method, the author has recorded the life
history of Rosa González Gómez, a Mexican woman who spends part of
each year in the United States and part in Mexico. Comparing the
story of Rosa's life, as told in her own words, with literature in the
social...
