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Articles 541 - 570 of 584

Full-Text Articles in Biology

Ets-Core Binding Factor: A Common Composite Motif In Antigen Receptor Gene Enhancers, Batu Erman, Marta Cortes, Barbara S. Nikolajczyk, Nancy A. Speck, Ranjan Sen Dec 1997

Ets-Core Binding Factor: A Common Composite Motif In Antigen Receptor Gene Enhancers, Batu Erman, Marta Cortes, Barbara S. Nikolajczyk, Nancy A. Speck, Ranjan Sen

Dartmouth Scholarship

A tripartite domain of the murine immunoglobulin μ heavy-chain enhancer contains the μA and μB elements that bind ETS proteins and the μE3 element that binds leucine zipper-containing basic helix-loop-helix (bHLH-zip) factors. Analysis of the corresponding region of the human μ enhancer revealed high conservation of the μA and μB motifs but a striking absence of the μE3 element. Instead of bHLH-zip proteins, we found that the human enhancer bound core binding factor (CBF) between the μA and μB elements; CBF binding was shown to be a common feature of both murine and human enhancers. Furthermore, mutant enhancers that bound …


Las Vegas Wash Water Quality Monitoring Program: 1996 Report Of Findings, Richard A. Roline, James J. Sartoris, U.S. Bureau Of Reclamation, U.S. Geological Survey Apr 1997

Las Vegas Wash Water Quality Monitoring Program: 1996 Report Of Findings, Richard A. Roline, James J. Sartoris, U.S. Bureau Of Reclamation, U.S. Geological Survey

Publications (WR)

Las Vegas Wash, a natural wash east of the city of Las Vegas, Nevada, carries stormwater, groundwater drainage, and sewage effluent from three sewage treatment plants to Lake Mead. The Wash provides nearly the only surface water outlet for the entire 2,193 mi2 of Las Vegas Valley. A drainage area of 1,586 mi2 contributes directly to the Wash through surface flow which is channeled to Las Vegas Bay of Lake Mead, while drainage of the remaining 607 mi2 is presumably subsurface and may drain toward Las Vegas Wash.

In the 1930's and 1940's, sewage treatment plants were …


Endosome To Golgi Retrieval Of The Vacuolar Protein Sorting Receptor, Vps10p, Requires The Function Of The Vps29, Vps30, And Vps35 Gene Products, Matthew N. J. Seaman, Eric G. Marcusson, Joan Lin-Cereghino, Scott D. Emr Apr 1997

Endosome To Golgi Retrieval Of The Vacuolar Protein Sorting Receptor, Vps10p, Requires The Function Of The Vps29, Vps30, And Vps35 Gene Products, Matthew N. J. Seaman, Eric G. Marcusson, Joan Lin-Cereghino, Scott D. Emr

College of the Pacific Faculty Articles

Mutations in the S. cerevisiae VPS29 and VPS30 genes lead to a selective protein sorting defect in which the vacuolar protein carboxypeptidase Y (CPY) is missorted and secreted from the cell, while other soluble vacuolar hydrolases like proteinase A (PrA) are delivered to the vacuole. This phenotype is similar to that seen in cells with mutations in the previously characterized VPS10 and VPS35 genes. Vps10p is a late Golgi transmembrane protein that acts as the sorting receptor for soluble vacuolar hydrolases like CPY and PrA, while Vps35p is a peripheral membrane protein which cofractionates with membranes enriched in Vps10p. The …


The Rna-Binding Site Of Bacteriophage Qβ Coat Protein, Francis Lim, Marc Spingola, David Peabody Dec 1996

The Rna-Binding Site Of Bacteriophage Qβ Coat Protein, Francis Lim, Marc Spingola, David Peabody

Biology Department Faculty Works

The coat proteins of the RNA bacteriophages Qβ and MS2 are specific RNA binding proteins. Although they possess common tertiary structures, they bind different RNA stem loops and thus provide useful models of specific protein-RNA recognition. Although the RNA-binding site of MS2 coat protein has been extensively characterized previously, little is known about Qβ. Here we describe the isolation of mutants that define the RNA-binding site of Qβ coat protein, showing that, as with MS2, it resides on the surface of a large β-sheet. Mutations are also described that convert Qβ coat protein to the RNA binding specificity of MS2. …


Interactions Involving The Human Rna Polymerase Ii Transcription/Nucleotide Excision Repair Complex Tfiih, The Nucleotide Excision Repair Protein Xpg, And Cockayne Syndrome Group B (Csb) Protein, Narayan Iyer, Michael S. Reagan, Kou-Juey Wu, Bertram Canagarajah, Errol C. Friedberg Feb 1996

Interactions Involving The Human Rna Polymerase Ii Transcription/Nucleotide Excision Repair Complex Tfiih, The Nucleotide Excision Repair Protein Xpg, And Cockayne Syndrome Group B (Csb) Protein, Narayan Iyer, Michael S. Reagan, Kou-Juey Wu, Bertram Canagarajah, Errol C. Friedberg

Biology Faculty Publications

The human basal transcription factor TFIIH plays a central role in two distinct processes. TFIIH is an obligatory component of the RNA polymerase II (RNAP II) transcription initiation complex. Additionally, it is believed to be the core structure around which some if not all the components of the nucleotide excision repair (NER) machinery assemble to constitute a nucleotide excision repairosome. At least two of the subunits of TFIIH (XPB and XPD proteins) are implicated in the disease xeroderma pigmentosum (XP). We have exploited the availability of the cloned XPB, XPD, p62, p44, and p34 genes (all …


Use Of The (3)H-Tetracycline Rat Model In The Study Of Skeletal Compartmentalization And Metabolism Of Calcium In The Maturing Male And Female Rat And The Role Of The Skeleton In Calcium Homeostasis In The Adolescent Male Rat, Darrin Lee Demoss Jan 1996

Use Of The (3)H-Tetracycline Rat Model In The Study Of Skeletal Compartmentalization And Metabolism Of Calcium In The Maturing Male And Female Rat And The Role Of The Skeleton In Calcium Homeostasis In The Adolescent Male Rat, Darrin Lee Demoss

Theses, Dissertations and Capstones

The (3)H-tetracycline bone labeling procedure was employed to monitor bone resorption from urinary loss curves in male and female rats of various ages. In addition, whole body dry skeletal mass and the loss of (3)H-tetracycline from individual bones was determined. It was found that the dry skeletal mass/body mass ratio of 24-week-old females was 30-40% greater than that for males. The urinary loss of (3)H-tetracycline was described by a double exponential equation indicating the presence of two distinct and independent exchangeable bone compartments. Both compartments decrease in size with age, but their label loss activities were different. The label loss …


Pattern Of Disease After Murine Hepatitis Virus Strain 3 Infection Correlates With Macrophage Activation And Not Viral Replication, M. Pope, O. Rotstein, E. Cole, S. Sinclair, Rebecca D. Parr, B. Cruz, R. Fingerote, S. Chung, R. Gorczynski, L. Fung, J. Leibowitz, Y. S. Rao, G. Levy Sep 1995

Pattern Of Disease After Murine Hepatitis Virus Strain 3 Infection Correlates With Macrophage Activation And Not Viral Replication, M. Pope, O. Rotstein, E. Cole, S. Sinclair, Rebecca D. Parr, B. Cruz, R. Fingerote, S. Chung, R. Gorczynski, L. Fung, J. Leibowitz, Y. S. Rao, G. Levy

Faculty Publications

Murine hepatitis virus strain (MHV-3) produces a strain-dependent pattern of disease which has been used as a model for fulminant viral hepatitis. This study was undertaken to examine whether there was a correlation between macrophage activation and susceptibility or resistance to MHV-3 infection. Peritoneal macrophages were isolated from resistant A/J and susceptible BALB/cJ mice and, following stimulation with MHV-3 or lipopolysaccharide (LPS), analyzed for transcription of mRNA and production of interleukin-1 (IL-1), tumor necrosis factor alpha (TNF-alpha), transforming growth factor beta (TGF-beta), mouse fibrinogen-like protein (musfiblp), tissue factor (TF), leukotriene B4, and prostaglandin E2 (PGE2). Macrophages from BALB/cJ mice produced …


The Cytoplasmic Tail Domain Of The Vacuolar Protein Sorting Receptor Vps10p And A Subset Of Vps Gene Products Regulate Receptor Stability, Function, And Localization, Joan Lin-Cereghino, Eric G. Marcusson, Scott D. Emr Sep 1995

The Cytoplasmic Tail Domain Of The Vacuolar Protein Sorting Receptor Vps10p And A Subset Of Vps Gene Products Regulate Receptor Stability, Function, And Localization, Joan Lin-Cereghino, Eric G. Marcusson, Scott D. Emr

College of the Pacific Faculty Articles

VPS10 of Saccharomyces cerevisiae encodes a type I transmembrane receptor protein required for the sorting of the soluble vacuolar hydrolase carboxypeptidase Y (CPY). To characterize the essential structural features and intercompartmental transport itinerary of the CPY receptor, we have constructed mutant forms of Vps10p that alter the carboxyterminal cytoplasmic tail of the protein. In addition, we have analyzed the effect these mutations as well as mutations in several VPS genes have on the function, stability, and localization of Vps10p. Although wild-type Vps10p is very stable over a 3-h chase period, overproduction of Vps10p results in PEP4-dependent degradation of the receptor. …


Molecular Mimicry Between Fc Receptor And S Peplomer Protein Of Mouse Hepatitis Virus, Bovine Corona Virus, And Transmissible Gastroenteritis Virus [Abstract], Emilia L. Oleszak, Jacek Kuzmak, Brenda Hogue, Rebecca D. Parr, Ellen W. Collisson, L. Scott Rodkey, Julian L. Leibowitz Jan 1995

Molecular Mimicry Between Fc Receptor And S Peplomer Protein Of Mouse Hepatitis Virus, Bovine Corona Virus, And Transmissible Gastroenteritis Virus [Abstract], Emilia L. Oleszak, Jacek Kuzmak, Brenda Hogue, Rebecca D. Parr, Ellen W. Collisson, L. Scott Rodkey, Julian L. Leibowitz

Faculty Publications

No abstract provided.


Altering The Rna Binding Specificity Of A Translational Repressor, F Lim, Marc Spingola, D Peabody Mar 1994

Altering The Rna Binding Specificity Of A Translational Repressor, F Lim, Marc Spingola, D Peabody

Biology Department Faculty Works

The coat proteins of RNA phages MS2 and GA are specific RNA-binding proteins which function to encapsidate viral RNA and to translationally repress synthesis of the viral replicase. The two proteins have highly homologous amino acid sequences, yet they show different RNA binding specificities, recognizing RNA stem-loop structures which differ primarily in the nucleotide sequences of their loops. We sought to convert MS2 coat protein to the RNA binding specificity of GA through the introduction of GA-like amino acid substitutions into the MS2 coat protein RNA-binding site. The effects of the mutations were determined by measuring the affinity of the …


Study Of Existing Information Concerning Water Quality Within Lake Mead, Vicki Scharnhorst, Southern Nevada Water Authority Feb 1994

Study Of Existing Information Concerning Water Quality Within Lake Mead, Vicki Scharnhorst, Southern Nevada Water Authority

Publications (WR)

The purpose of Task 010A15M of the Southern Nevada Water Authority (SNWA) Treatment and Transmission Facility (TTF) contract is to conduct a study of existing information concerning water quality within Lake Mead and identify additional water quality studies that are needed to supplement existing data. The objective of this task is not to discuss treatability of the raw water source; this is addressed by Task 010A18M, "Define Water Treatment Requirements." In addition, a narrative on the effect of pending Safe Drinking Water Act amendments and a determination of treated water quality goals is included in Task 010A16M, "Review Safe Drinking …


The Primary Structure Of A Fungal Chitin Deacetylase Reveals The Function For Two Bacterial Gene Products., Dimitris Kafetzopoulos, George Thireos, John N. Vournakis, Vassilis Bouriotis Sep 1993

The Primary Structure Of A Fungal Chitin Deacetylase Reveals The Function For Two Bacterial Gene Products., Dimitris Kafetzopoulos, George Thireos, John N. Vournakis, Vassilis Bouriotis

Dartmouth Scholarship

Chitin deacetylase (EC 3.5.1.41) hydrolyzes the N-acetamido groups of N-acetyl-D-glucosamine residues in chitin. A cDNA to the Mucor rouxii mRNA encoding chitin deacetylase was isolated, characterized, and sequenced. Protein sequence comparisons revealed significant similarities of the fungal chitin deacetylase to rhizobial nodB proteins and to an uncharacterized protein encoded by a Bacillus stearothermophilus open reading frame. These data suggest the functional homology of these evolutionarily distant proteins. NodB is a chitooligosaccharide deacetylase essential for the biosynthesis of the bacterial nodulation signals, termed Nod factors. The observed similarity of chitin deacetylase to the B. stearothermophilus gene product suggests that this gene …


Gal4 Disrupts A Repressing Nucleosome During Activation Of Gal1 Transcription In Vivo, Jeffrey D. Axelrod, Michael S. Reagan, John Majors May 1993

Gal4 Disrupts A Repressing Nucleosome During Activation Of Gal1 Transcription In Vivo, Jeffrey D. Axelrod, Michael S. Reagan, John Majors

Biology Faculty Publications

Photofootprinting in vivo of GALl reveals an activation- dependent pattern between the UASG and the TATA box, in a sequence not required for transcriptional activation by GAL4. The pattern results from a nucleosome whose position depends on sequences within the UASG. In the wild-type gene, activation by GAL4 and derivatives disrupts this nucleosome. This activity is independent of interactions with DNA-bound core transcription factors and is proportional to the strength of the activator. Presence of the nucleosome correlates with low basal transcription levels under various conditions, suggesting a role in limiting basal expression. We propose a role for the GAL4 …


Dietary Protein Deficiency And Mycobacterium Bovis Bcg Affect Interleukin-2 Activity In Experimental Pulmonary Tuberculosis, David N. Mcmurray, C. L. Mintzer, R. A. Bartow, Rebecca D. Parr Sep 1989

Dietary Protein Deficiency And Mycobacterium Bovis Bcg Affect Interleukin-2 Activity In Experimental Pulmonary Tuberculosis, David N. Mcmurray, C. L. Mintzer, R. A. Bartow, Rebecca D. Parr

Faculty Publications

Inbred strain 2 guinea pigs were vaccinated with Mycobacterium bovis BCG or were left unvaccinated. They were maintained for 6 weeks on defined, isocaloric diets containing either 30% (control animals) or 10% (animals receiving low protein) ovalbumin as the sole protein source. Animals were challenged by the respiratory route with a low dose of virulent M. tuberculosis H37Rv and killed 4 weeks later. Protein-malnourished animals were not protected by previous vaccination with BCG. Lymphocytes isolated from various tissues were tested in vitro for proliferative responses to mitogen (concanavalin A) and antigen (purified protein derivative [PPD]), production of interleukin-2 (IL-2), and …


Limnological Monitoring Data For Lake Mead During 1988, Suzanne E. Leavitt, Larry J. Paulson, State Of Nevada: Division Of Environmental Protection Apr 1989

Limnological Monitoring Data For Lake Mead During 1988, Suzanne E. Leavitt, Larry J. Paulson, State Of Nevada: Division Of Environmental Protection

Publications (WR)

Limnological monitoring was conducted in Las Vegas Bay and Boulder Basin from April to December of 1988. The purpose of the monitoring was to (i) document possible changes in water quality resulting from decreased phosphorus loading and increased ammonia in Las Vegas Wash, and (ii) establish a data base for evaluating the adequacy of water quality standards.


Expression Of Holo And Apo Forms Of Spinach Acyl Carrier Protein-I In Leaves Of Transgenic Tobacco Plants, M. A. Post-Beittenmiller, Katherine M. Schmid, J. B. Ohlrogge Jan 1989

Expression Of Holo And Apo Forms Of Spinach Acyl Carrier Protein-I In Leaves Of Transgenic Tobacco Plants, M. A. Post-Beittenmiller, Katherine M. Schmid, J. B. Ohlrogge

Scholarship and Professional Work - LAS

Acyl carrier protein (ACP) is a chloroplast-localized cofactor of fatty acid synthesis, desaturation, and acyl transfer. We have transformed tobacco with a chimeric gene consisting of the tobacco ribulose-1,5-bisphosphate carboxylase promoter and transit peptide and the sequence encoding the mature spinach ACP-I. Spinach ACP-I was expressed in the transformed plants at levels twofold to threefold higher than the endogenous tobacco ACPs as determined by protein immunoblots and assays of ACP in leaf extracts. In addition to these elevated levels of the holo form, there were high levels of apoACP-I, a form lacking the 4'-phosphopantetheine prosthetic group and not previously detected …


Characterization Of The Aquatic Environment In Lake Mead Near The Proposed Spring Canyon Pumped-Storage Project, And Assessment Of Potential Aquatic Impacts, Charles R. Liston, Stephen J. Grabowski, Bureau Of Reclamation Jun 1988

Characterization Of The Aquatic Environment In Lake Mead Near The Proposed Spring Canyon Pumped-Storage Project, And Assessment Of Potential Aquatic Impacts, Charles R. Liston, Stephen J. Grabowski, Bureau Of Reclamation

Publications (WR)

A pumped storage system consists of an upper reservoir and lower reservoir separated by an elevation difference. During low demand energy periods such as nights and weekends water is pumped from the lower to the upper reservoir using available energy from conventional steam electric power plants. During high energy demand periods, such as mornings and afternoons of weekdays, upper reservoir water is allowed to drop back down through the same system of water conduits and turbines, generating electricity to conveniently meet abrupt electrical energy requirements. The same water turbines thus act both as pumps and as conventional hydroelectric turbines. Because …


Limnological Monitoring Data For Lake Mead During 1987: Technical Report No. 20, Larry J. Paulson Jan 1988

Limnological Monitoring Data For Lake Mead During 1987: Technical Report No. 20, Larry J. Paulson

Publications (WR)

Limnological monitoring was conducted in Las Vegas Bay and Boulder Basin from April to December of 1987. The purpose of the monitoring was to (i) document possible changes in water quality resulting from decreased phosphorus loading in Las Vegas Wash, and (ii) establish a data base for evaluating the adequacy of water quality standards.


Changes In The Morphometry Of Las Vegas Wash And The Impact On Water Quality, Richard A. Roline, James J. Sartoris, U.S. Bureau Of Reclamation Jan 1988

Changes In The Morphometry Of Las Vegas Wash And The Impact On Water Quality, Richard A. Roline, James J. Sartoris, U.S. Bureau Of Reclamation

Publications (WR)

Las Vegas Wash, a natural wash east of Las Vegas, Nevada, carries stormwater, groundwater drainage, and sewage effluent from two sewage treatment plants to Lake Mead. Over 80 percent of the normal discharge of approximately 3.4 m3/s (120 ft3/s) consists of effluent from the City of Las Vegas and Clark County sewage treatment plants. Beginning in the 1950s, a large wetland area developed along the wash that supported waterfowl populations and contributed to some water quality transformations. Heavy rains and subsequent flooding in the area in 1983 and 1984 resulted in erosion and channelization that greatly …


Lake Mead Cover Enhancement Project, Jennifer Stevens Haley, Suzanne Leavitt, Larry Paulson, Donald H. Baepler Jul 1987

Lake Mead Cover Enhancement Project, Jennifer Stevens Haley, Suzanne Leavitt, Larry Paulson, Donald H. Baepler

Publications (WR)

Ninety-three wildlife agencies were surveyed for information on their attempts to improve fish habitat. In addition, an annotated bibliography including over 100 summaries was completed on: 1. largemouth bass cover requirements and preferences, 2. use and effectiveness of artificial cover, 3. aquatic plant introduction and species requirements for germination and establishment, 4. terrestrial plant introduction and species requirements for germination and establishment, and 5. nutrient exchange between sediment, aquatic plants, and water. A reconnaissance of existing terrestrial and aquatic vegetation was completed in June 1986 including the production of a video tape of the Nevada shoreline of Lake Mead. Cover …


Quantitation And Identification Of Organic N-Chloramines Formed In Stomach Fluid On Ingestion Of Aqueous Hypochlorite, Frank E. Scully Jr., Katherine Mazina, Daniel E. Sonenshine, Frederick Kopfler Jan 1986

Quantitation And Identification Of Organic N-Chloramines Formed In Stomach Fluid On Ingestion Of Aqueous Hypochlorite, Frank E. Scully Jr., Katherine Mazina, Daniel E. Sonenshine, Frederick Kopfler

Biological Sciences Faculty Publications

The chemical reactions that hypochlorite undergoes in the body when chlorinated water is ingested have received very little attention. Because amino nitrogen compounds are important components of the average diet, the reactions of hypochlorite with amino compounds in the stomach were investigated. Stomach fluid was recovered from Sprague-Dawley rats that had been fasted for 48 hr and administered 4 mL deionized water. The chlorine demand of the stomach fluid was determined. An average volume-independent demand of 2.7 mg chlorine was measured. At doses below 40 mg/L chlorine reducing reactions appeared to account for reduction of all oxidizing species within 15 …


Acetylcholinesterase In The Neonatal Rat Brain: The Effects Of Prenatal Ethanol Exposure, Linda M. Boland Jul 1985

Acetylcholinesterase In The Neonatal Rat Brain: The Effects Of Prenatal Ethanol Exposure, Linda M. Boland

Biological Sciences Theses & Dissertations

Acetylcholinesterase (AChE) activity in the neonatal rat brain was determined by histochemical localization and quantitative biochemical analysis. AChE-positive perikarya were concentrated in the neostriatum, globus pallidus, medial habenular nucleus, amygdaloid complex, various hypothalamic nuclei, gigantocellular and paragigantocellular reticular nuclei, raphe nuclei, locus coeruleus, and motor nuclei of cranial nerves III-VII and IX-XII. Some areas stained differently or not at all when compared with the adult rat brain. The effects of prenatal ethanol exposure on regional AChE activity were assessed by comparing enzyme levels in offspring exposed via maternal consumption of a liquid diet containing 35 percent ethanol derived calories. This …


Concanavalin A-Binding Enzymes Of Crotalus Scutulatus Scutulatus Venom, Michael W. Hinson, C. K. Childs, Bob D. Johnson, Dewey H. Sifford Jan 1985

Concanavalin A-Binding Enzymes Of Crotalus Scutulatus Scutulatus Venom, Michael W. Hinson, C. K. Childs, Bob D. Johnson, Dewey H. Sifford

Journal of the Arkansas Academy of Science

Crotalus scutulatus scutulatus crude venom was separated into two fractions by Concanavalin A Sepharose 4B affinity chromatography. The proteins binding to Con A exhibited phosphomonoesterase (orthophosphoric monoester phosphohydrolase EC 3.1.3.2), phosphodiesterase, 5'-nucleotidase (5'-ribonucleotide phosphohydrolase EC 3.1.3.5), phospholipase A(phosphatidate 2-acylhydrolase EC 3.1.1 .4), hyaluronidase (hyaluronate glycanohydrolase EC 3.2.1 d), N-benzoyl-L-arginine ethyl esterase, p-toluenesulfonyl-L-arginine methyl esterase, L-amino acid oxidase (L-amino acid: 02 oxidoreductase [deaminating] EC 1.4.3.2), and caseinolytic activities. Thrombin-like and NAD nucleosidase (5'-ribonucleotide phosphohydrolase EC 3.1.3.5) activities were not observed. The crude venom and the fraction containing the glycoproteins which bound to Con A were fractionated by DEAE Sephadex A-50 ion …


Las Vegas Wash Advanced Water Quality Study: Final Report, Richard A. Roline, James J. Sartoris, U.S. Bureau Of Reclamation Jan 1984

Las Vegas Wash Advanced Water Quality Study: Final Report, Richard A. Roline, James J. Sartoris, U.S. Bureau Of Reclamation

Publications (WR)

The purpose of the Las Vegas Wash Advanced Water Quality Study is to determine the existence, extent, and mechanisms of nutrient and toxin stripping in Las Vegas Wash under present conditions and under future conditions, both with and without construction of the proposed salinity control unit as described by the Bureau of Reclamation (USBR, 1982b). This study was performed for the Lower Colorado Region Division of Planning by personnel of the Environmental Sciences Section of the Division of Research and Laboratory Services, E&R Center, Denver, Colorado. Work on the study began in February 1983. The general approach adopted for this …


Historical Patterns Of Phytoplankton Productivity In Lake Mead, Richard T. Prentki, Larry J. Paulson Jan 1983

Historical Patterns Of Phytoplankton Productivity In Lake Mead, Richard T. Prentki, Larry J. Paulson

Publications (WR)

Lake Mead was impounded in 1935 by the construction of Hoover Dam. The Colorado River was unregulated prior to then and therefore was subjected to extreme variations in flows and suspended sediment loads. Hoover Dam stabilized flows and reduced suspended sediment loads downstream, but Lake Mead still received silt-laden inflows from the upper Colorado River Basin. The Colorado River contributed 97% of the suspended sediment inputs to Lake Mead, and up to 140 x 1O6 metric tons (t) entered the reservoir in years of high runoff. Most of the sediments were deposited in the river channel and formed an …


Effects Of Wastewater Discharges On Periphyton Growth In Lake Mead, Nevada-Arizona, Marsha Korb Morris Dec 1982

Effects Of Wastewater Discharges On Periphyton Growth In Lake Mead, Nevada-Arizona, Marsha Korb Morris

Publications (WR)

A study of the effects of secondary-treated wastewater on periphyton growth in Lake Mead, Nevada-Arizona was conducted from September 1979 to December 1980. Periphyton ash-free dry weight, chlorophyll-a, dominant species composition, and alkaline phosphatase activity were measured on fiberglass substrates. Substrates were incubated for two to four weeks in littoral and limnetic habitats. Physical and chemical variables and phytoplankton chlorophyll-a were measured concurrently.

Transparency increased with increasing distance from the discharge. Secchi depth ranged from 0.75 m at the discharge confluence (station 2) in August, to greater than 20 m at the most distant stations (stations 9 and 10) in …


The Voluntary Water Quality Monitoring Program : 1982 Project Report, Barbara Welch, Judy Potvin, Mary Ellen Dennis Jan 1982

The Voluntary Water Quality Monitoring Program : 1982 Project Report, Barbara Welch, Judy Potvin, Mary Ellen Dennis

Maine Collection

The Voluntary Water Quality Monitoring Program : 1982 Project Report

by Barbara Welch, Judy Potvin & Mary Ellen Dennis

Division of Environmental Evaluation and Lake Studies, Maine Department of Environmental Protection, Augusta, Maine 1982.

Contents: Understanding Maine's Lakes and Ponds / Acknowledgement / Temperature / Dissolved Oxygen / Other Measures of Lake Water Quality / Nutrients / Algae and Chlorophyll a / Transparency / Morphometry / Sampling / Protection / Classification / Answers to Most Frequently Asked Questions / Glossary of Terms / Appendix A : Maximum, Minimum, and Mean Values / Appendix B : Phosphate Content of Common Cleansers …


Organic N-Chloramines: Chemistry And Toxicology, Frank E. Scully, Jr., Maxwell A. Bempong Jan 1982

Organic N-Chloramines: Chemistry And Toxicology, Frank E. Scully, Jr., Maxwell A. Bempong

Chemistry & Biochemistry Faculty Publications

The stability of aqueous solutions of organic N-chloramines, suspected of contaminating chlorinated water, has been studied. Two factors influence the decomposition of solutions of N-chloropiperidine and N-chlorodiethylamine: a spontaneous decomposition and photodecomposition. Since solutions of these compounds are relatively long-lived, a need for an analytical method for their identification is discussed. A new method is described which involves reaction of organic N-chloramines with arenesulfinic acid salts. The method gives high yields of stable arenesulfonamides. Several toxicological studies of N-chloropiperidine are described. The compound is mutagenic by Ames assay in Salmonella typhimurium strain TA 100 and does not require metabolic activation …


Ascorbic Acid, Lipid Peroxidation, And Aging, Brian Evan Leibovitz May 1979

Ascorbic Acid, Lipid Peroxidation, And Aging, Brian Evan Leibovitz

Dissertations and Theses

The role of ascorbic acid with regard to lipid peroxidation and aging has been examined. A thorough literature analysis indicates that free radical-induced lipid peroxidation is a plausible biochemical explanation for aging. Lipid peroxidation causes cellular damage due to altered enzyme activities, error-prone nucleic acid metabolism, and membrane dysfunction, as well as the accumulation of aging pigments in the lysomes. Ascorbic acid, a water soluble free radical quencher, was examined with regard to carbon tetra-chloride-induced lipid peroxidation and in vivo aging. Carbon tetrachloride, a well-known free radical inducer, caused marked increases in the ration of oxidized/reduced vitamin C only …


Steriodogenesis In Mouse Preimplantation Embryos, Marcia E. Kendall Feb 1979

Steriodogenesis In Mouse Preimplantation Embryos, Marcia E. Kendall

Morehead State Theses and Dissertations

A thesis presented to the faculty of the School of Sciences and Mathematics at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science in Biology by Marcia E. Kendall February 8, 1979.