Life Sciences Commons^™

Nutrient Limitation In A Southwestern Desert Reservoir: Eutrophication Of Las Vegas Bay, Lake Mead, Nevada, Davine M. Lieberman

Publications (WR)

Algal bioassay tests were conducted with Selenastrum capricornutum and natural algae on inner Las Vegas Bay, Lake Mead, Nevada, from December 1992 through September 1993, to identify any nutrient limitation in an area of the reservoir that has experienced problems associated with severe nutrient enrichment. Three areas were sampled based on a gradient of water quality conditions that existed in Las Vegas Bay (LVB). Disodium ethylenedinitrilotetraacetate (EDTA) significantly stimulated algal growth compared to non-EDTA treatment. Algal bioassays indicated that phosphorus (P) was the primary limiting nutrient at all stations for most of the test dates. Chl a response with EDTA …

Trophic Transfer Of Fatty Acids, Sterols, And A Triterpenoid Alcohol Between Bacteria, A Ciliate, And The Copepod Acartia Tonsa, Melissa C. Ederington, George B. Mcmanus, H. Rodger Harvey

OES Faculty Publications

The incorporation of lipids into the copepod Acartia tonsa and its eggs was measured when it was fed either a bacterivorous ciliate (Pleuronema sp.) or a diatom (Thalassiosira weissflogii). Egg production was 10-fold higher on the diatom diet, whereas hatch success of eggs was the same for algal and ciliate diets. Adult copepods fed diatoms contained more total fatty acid and sterols than copepods fed the ciliate diet, and individual lipids reflected the dietary source. Eggs from diatom-fed copepods had fewer fatty acids but more sterols than eggs from copepods on a ciliate diet. Ciliate-fed copepods and …

Community Metabolism And Nutrient Cycling In The Mississippi River Plume: Evidence For Intense Nitrification At Intermediate Salinities, Joseph D. Pakulski, Ronald Benner, Rainer Amon, Brian Eadie, Terry Whitledge

Faculty Publications

Community respiration, net nutrient fluxes and heterotrophic bacterial production were investigated in the Mississippi River (USA) plume during May 1992 using dark bottle incubations of unfiltered water. Highest rates of community O₂ consumption and dissolved inorganic carbon regeneration were observed at intermediate (10 to 27%₀) plume salinities. Plume surface 0₂ consumption rates were 2- to 4-fold greater than rates reported previously during the summer and winter. Heterotrophic bacterial production ([³H]-leucine incorporation) was also highest at intermediate salinities and 2- to 4-fold greater than rates reported from other seasons. Net regeneration of NH₄^{+ …}

G95-1259 Wildlife And Disease--Public Health Concerns, Dallas Virchow, Scott E. Hygnstrom, Wayne L. Kramer

University of Nebraska-Lincoln Extension: Historical Materials

This NebGuide describes human health risks and symptoms associated with prominent diseases of Nebraska's wildlife. Listed are precautions for minimizing exposure and preventing infection.

Zoonoses (zoe-uh'-no-sez') are diseases that can be transmitted from animals to humans. Wild animals and domestic animals share some disease-causing organisms and either group can transmit diseases to people. Transmission can occur directly through contact with tissues or body fluids of animals. Indirect transmission can occur through insects, ticks and mites that feed on infected animals.

G95-1264 Storing Fresh Fruits And Vegetables, Susan D. Schoneweis, Durward Smith

University of Nebraska-Lincoln Extension: Historical Materials

The following NebGuide outlines proper storage methods and conditions for fresh fruits and vegetables.

Harvesting fruits and vegetables from your garden at the proper stage of maturity is only the first step to fresh table quality. Proper harvesting and post-harvest handling methods, as well as proper storage of fruits and vegetables not immediately eaten, will help maintain the flavor, texture and nutritive value of the produce.

Proper storage means controlling both the temperature and relative humidity of the storage area. All fruits and vegetables do not have the same requirements. This NebGuide will help you select the best storage conditions …

Mechanisms For Soil Moisture Effects On Activity Of Nitrifying Bacteria, John M. Stark, M. K. Firestone

Biology Faculty Publications

Moisture may limit microbial activity in a wide range of environments including salt water, food, wood, biofilms, and soils. Low water availability can inhibit microbial activity by lowering intracellular water potential and thus reducing hydration and activity of enzymes. In solid matrices, low water content may also reduce microbial activity by restricting substrate supply. As pores within solid matrices drain and water films coating surfaces become thinner, diffusion path lengths become more tortuous, and the rate of substrate diffusion to microbial cells declines. We used two independent techniques to evaluate the relative importance of cytoplasmic dehydration versus diffusional limitations in …

Mechanisms For Soil Moisture Effects On Activity Of Nitrifying Bacteria, John M. Stark, M. K. Firestone

John M. Stark

Moisture may limit microbial activity in a wide range of environments including salt water, food, wood, biofilms, and soils. Low water availability can inhibit microbial activity by lowering intracellular water potential and thus reducing hydration and activity of enzymes. In solid matrices, low water content may also reduce microbial activity by restricting substrate supply. As pores within solid matrices drain and water films coating surfaces become thinner, diffusion path lengths become more tortuous, and the rate of substrate diffusion to microbial cells declines. We used two independent techniques to evaluate the relative importance of cytoplasmic dehydration versus diffusional limitations in …

In Vitro Activity Of Four Fluoroquinolones On Selected Bacteria, Sheryl L. Pullen

University of the Pacific Theses and Dissertations

In 1990-1991, in a national surveillance study, and in 1991-1992, in a followup study, both by Thornsberry et al. (1993), ciprofloxacin data from various geographical and demographical institutions were collected. Several species of bacteria have shown resistance to ciprofloxacin and norfloxacin, but the degree of resistance to these drugs has not been reported for the Stockton area. To determine the extent of this resistance, Dameron Hospital antibiograms generated from 1990 to 1994 were reviewed and compared. Results of the comparison show that susceptibility among the Gram-negative isolates, with the exception of Providencia stuartii, Acinetobacter lwoffi, and to a lesser extent …