The Federal Water Pollution Control Act Amendments of 1972
prohibits the discharge of seafood processing solid wastes into
navigable waters after July 1, 1977. Oregon shrimp and crab processors
must use other methods of disposal for the 15 to 30 million
pounds of solid waste generated annually. The application of...
The North Atlantic zone of Costa Rica is an alluvial plain, whose fairly good soils and warm, extremely wet climate generate serious weed problems in cultivated crops and pastureland. Basic foods - corn, beans, rice and yuca - are important small farm crops. New land is still being opened for...
Charge transport in a semiconductor structure with heterojunction is described by a multiscale partial differential equation model. This model can be used, e.g., for the design of more efficient solar cells. Phenomena at the heterojunction must be resolved at the angstrom scale while the size of the device is that...
Grain yield and grain protein are often negatively associated in
wheat. When yield increases and grain protein decreases, there can be
an adverse effect on the milling and baking quality if the desired end
product is bread flour. It has been suggested that this inverse
association is the result of...
Twenty-one rice cultivars were evaluated to determine the difference between populations of Sogatodes oryzicola (Muir) (Homoptera: Delphacidae) in Costa Rica and Colombia, Survival, mortality and population development of S. oryzicola on five selected cultivars was used to determine levels of plant resistance. The importance and potential of the parasitoid-predator Haplogonatopus...
Mycorrhizae are important for plant growth, particularly in nutritionally poor soils. Vesicular-arbuscular mycorrhizae (VAM) are the primary form of mycorrhizae found in tropical plants, and their persistence in the soil as colonizing fungal propagules following deforestation cannot be directly
measured. Utilizing the "most probable number" (MPN) method for estimating infective...
Human activities have altered Earth’s ecosystems. Most biomes have experienced a 20-50% conversion to human use. Loss of habitat has obvious effects on the persistence of species. Fragmentation, however, may also negatively affect biodiversity for those species that exhibit behavioral responses to changes in habitat configuration. Such behavioral changes include...
At the Costa Rica Dome (CRD), upwelling associated with cyclonic circulation and the presence of a shallow thermocline support a highly productive biological habitat, exploited by marine fauna at several trophic levels. During January 2008, a cruise to the CRD by the R/V Pacific Storm was conducted to relocate blue...
The growth of Alnus acuminata (HBK) 0. Ktze, Cupressus
lusitanica Mill., Gmelina arborea Roxb, Pinus caribaea var. hondurensis
Barr. & Golf., and Tectona grandis L. in Costa Rica and
twenty seven soil and climatic factors were analyzed to determine
the relationship between major environmental factors and growth
rates of these...
Heat flow analysis of the Costa Rica convergent margin is carried out for seven core sites drilled during Integrated Ocean Drilling Program (IODP) Expeditions 334 and 344 as part of the Costa Rica Seismogenesis Project (CRISP). These expeditions were designed to develop a better understanding of erosional subduction zones. Heat...
This Thesis explores the possibility of increased export and
export earnings stability for Costa Rica after the implementation of
the Caribbean Basin Economic Recovery Act (CBERA) or Caribbean Basin
Initiative (CBI). It was expected that this policy would not only
increase trade and exports for some developing nations in the...
The corvina reina (Cynoscion albus) is an important part of the artisanal fishery
in the Gulf of Nicoya, Costa Rica. Stock assessment on this sciaenid species has been
restricted to the use of length-based methods because of the lack of age data. Direct age
determination methodologies for tropical species often...
Landscape positions have been used to determine soil properties. My soil study in Monteverde on the Pacific slope of Costa Rica was designed to examine soil-landscape relationships for sites with various land use histories and management. Soil pits were dug at Nacimiento y Vida, Crandell, Curi-cancha, La Calandria, and Finca...
Knowledge of the mean recharge elevation (MRE) of water resources is
important for informing conservation and protection practices where water security is threatened by population growth, urban expansion, and land and climate changes. In this study a Bayesian approach was developed and applied to determine the MRE of 682 surface...
Preliminary studies with a dog (Canis familiaris) and a coyote
(Canis latrans) showed that these carnivores can serve as definitive
hosts in the life cycle of Sarcocystis fusiformis of cattle (Bos
taurus) and a microscopic Sarcocystis of mule deer (Odocoileus
hemionus hemionus). Preliminary studies to determine effects of the
cervine...
Wine is particularly vulnerable to infection by Brettanomyces bruxellensis during or shortly after malolactic fermentation (MLF). While different methods and techniques enable winemakers to prevent wine spoilage due to this organism, no single intervention is universally sufficient. Moreover application of sulfur dioxide, the most commonly used of these methods, is...