Large “hypercarnivorous” felids are recognized for their role as apex predators and hence as key elements in food webs and ecosystem functioning through competition and depredation. Here we show that cougars (Puma concolor), one of the largest and the most widely ranging apex felid predators with a strictly carnivorous diet,...
This research was undertaken to provide barley growers, processors, and consumers with quality food barley. Because all currently available varieties of food barley are of spring growth habit, the first phase of the research involved agronomic assessment of these varieties under Oregon conditions. Because winter barley usually yields more than...
Tree-like patterns are ubiquitous in nature. Botanical trees, river networks, and blood systems are the most well-known examples of complex hierarchical systems met in observations. Interestingly, many of such systems exhibit statistical self-similarity. There are two main types of self-similarity: Horton self-similarity and Tokunaga self-similarity. Although there is an increased...
As ecologists are being called upon to predict the consequences of human
perturbations to natural communities, an important goal is to understand what factors
drive variability or consistency in nature.
In the rocky intertidal of San Juan Island, Washington, a comparative
experimental approach was used to investigate spatial and temporal...
Four studies were conducted in the llama (Lama glama) evaluating changes in reproductive physiology, vaginal cytology, and growth. Study I. Temporal changes in vaginal cytology were correlated with alterations in serum estradiol -17β and progesterone concentrations. A 2 * 2 factorial study examined the treatment effects of a) concurrent male...
This thesis presents a discussion of the main materialistic theories proposed to explain the process of development among the indigenous population of Latin America. Four theoretical approaches are presented and discussed. The first one deals with the social group referred to as peasants. The second one explains the process of...
During the Last Glacial Maximum (LGM, ∼ 21 ky before present) the atmospheric CO2 concentration was about 100 ppm lower than its pre-industrial (PI)value. The missing carbon from the atmosphere must have been stored in thedeep ocean during this period, but the mechanisms driving such re-distribution ofthe carbon cycle are...
This research project is an historical case study of the conflict
which evolved from the deliberations and subsequent implementation
of bilingual education in Central School District 13J, Independence,
Oregon. The time period under consideration spans 35 months,
beginning in August 1974, when district officials first proposed bilingual
education, and ending...
In the wake of the ``third wave'' of democratization, scholars and practitioners were optimistic regarding the ease with which countries could adopt democratic norms and institutions. However, after four decades of democracy, many competitive regimes have not improved government probity or developed strong forms of accountability. Levels of economic and...
Oxidative stress is recognized as an important underlying factor in the
pathogenesis of many degenerative diseases as well as normal senescence. The
free radicals, reactive oxygen species (ROS) and electrophiles produced during
oxidative stress are capable of modifying nucleic acids, lipids and proteins. There
are a variety of oxidative modifications...