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Articles 361 - 390 of 404

Full-Text Articles in Microbiology

Escherichia Coli O157:H7 In Free-Ranging Deer In Nebraska, David G. Renter, Jan M. Sargeant, Scott E. Hygnstrom, Jeff D. Hoffmann, Jerry R. Gillespie Jan 2001

Escherichia Coli O157:H7 In Free-Ranging Deer In Nebraska, David G. Renter, Jan M. Sargeant, Scott E. Hygnstrom, Jeff D. Hoffmann, Jerry R. Gillespie

School of Natural Resources: Faculty Publications

In order to determine the prevalence and distribution of the human pathogen, Escherichia coli O157:H7, in free-ranging deer, hunters were asked to collect and submit fecal samples from deer harvested during a regular firearm season (14–22 November 1998). Prior to the season, 47% of the hunters with permits in the southeastern Nebraska (USA) study area indicated a willingness to participate in the study. Approximately 25% of successful hunters in the area submitted deer fecal samples. Escherichia coli O157:H7 was cultured from four (0.25%) of 1,608 total samples submitted. All of the fecal samples that were properly identified (1,426) and all …


Comparison Between Two Analytical Methods For Fecal Coliform Analysis In Natural Water: Membrane Filtration And Multiple Tube Fermentation, Mona M. Hafez Oct 2000

Comparison Between Two Analytical Methods For Fecal Coliform Analysis In Natural Water: Membrane Filtration And Multiple Tube Fermentation, Mona M. Hafez

Theses & Honors Papers

This study compares two different analytical methods for the determination of coliform bacteria within natural waters. The two methods are: 1) membrane Filtration, and 2) multiple tube fermentation. Water samples from ten different locations within the Appomattox River watershed were collected by technicians from the Piedmont Soil and Water Conservation District and the Piedmont Region TMDL Initiative in Farmville, Virginia.

The Membrane filtration (MF) method utilizes m-FC broth to isolate and differentiate total fecal coliform bacteria (E.coli, Klebsiella, Pseudomonas) in natural water samples. A 1% dilution of each water sample is filtered through a 0.45 micron (um) Millipore filter …


Bioaccumulation And Toxicity Studies Of Heavy Metals In Ankistrodesmus Convolutus Corda, Samina Hussin Jan 2000

Bioaccumulation And Toxicity Studies Of Heavy Metals In Ankistrodesmus Convolutus Corda, Samina Hussin

Student Works (2000-2009)

Nine freshwater microalgal species of Malaysia, Chlorella vulgaris (isolate 001). Scenedesmus sp. (isolate 039), Moug,wlia sp. (isolate 069). l llothrix sp. (isolate 071). Ch/ore/la sp. (isolate 078), Ankistrodf!snms co11vo/11tus (isolate IO I), Chlorococuum sp. (isolate 110), Synechococcus sp. (isolate 075). Euglena sp. (isolate 058), and including two species Oocystis polymorpha UTEX 1645 (isolate 169) and Ankistrodesmus arcuatus UTEX LB 1379 (isolate 170) from the UTEX Collection, Texas, were used in 96 h single heavy metal (Cd, Co, Cr. Cu, Fe, Mn and Zn) exposure static studies for preliminary toxicity test. This was done by incubating the microalgae in a range …


Development Of A Novel Method For Phenol Detection Using High Performance Thin Layer Chromatography, Danette Young Carlton Aug 1999

Development Of A Novel Method For Phenol Detection Using High Performance Thin Layer Chromatography, Danette Young Carlton

Theses & Honors Papers

The purpose of this study was to develop a more efficient method to test for phenol in both wastewater and non-wastewater. Phenol is a caustic and toxic contaminant that may be present in our water supplies. Phenol is used in various resins, pharmaceuticals, plastics and disinfectants. Environmental Protection Agency methods are available to test for phenol using gas chromatography along with mass spectrometry or flame ionization detection. Each of these methods can be a long, involved process consisting of extraction, many sample injections, and interference problems. This method developed an easier and less complicated approach of testing for phenol in …


The Timing And Pattern Of Myogenesis In Hymenochirus Boettgeri, Matthew T. Smetanick, Rafael O. De Sá Jun 1999

The Timing And Pattern Of Myogenesis In Hymenochirus Boettgeri, Matthew T. Smetanick, Rafael O. De Sá

Biology Faculty Publications

Differences in the relative timing of homologous developmental events among closely related species, known as heterochronies, may provide valuable clues in understanding evolutionary relationships (McKinney, 1988; McNamara, 1995). Examining the timing of myogenic events is a relatively easy and effective method for finding heterochronic events. For example, whether muscle proteins and myofibrils appear before or after multinucleation can be determined through histological techniques (Kielbowna, 1981). Simple observations of live specimens can pinpoint functional landmarks such as first twitch (spontaneous or due to external stimuli) and first heartbeat.


Development Of The Suprarostral Plate Of Pipoid Frogs, Rafael O. De Sá, Charles C. Swart Apr 1999

Development Of The Suprarostral Plate Of Pipoid Frogs, Rafael O. De Sá, Charles C. Swart

Biology Faculty Publications

The rostral region of nonpipoid tadpoles has two sets of cartilages, the cornua trabeculae and the suprarostral cartilages, whereas the rostral region in pipoid larvae is occupied by a single and continuous cartilage, the suprarostral plate. The homology of this region in pipoid and nonpipoids tadpoles has been controversial. We examined the early formation and development of the suprarostral plate using serially cross-sectioned specimens of Rhinophrynus, Xenopus, and Hymenochirus. We conclude that the cartilaginous structures present in the rostral area of pipoid and nonpipoid larvae are homologous. Furthermore, we found two different developmental patterns among pipoid larvae. The chondrocranium …


Osteological Analysis Of The Killifish Genus Cynolebias (Cyprinodontiformes: Rivulidae), Marcelo Loureiro, Rafael O. De Sá Jan 1999

Osteological Analysis Of The Killifish Genus Cynolebias (Cyprinodontiformes: Rivulidae), Marcelo Loureiro, Rafael O. De Sá

Biology Faculty Publications

Relationships among the species of the annual fish Cynolebias are unclear. An analysis of the variation and utility of osteological characters for phylogenetic analysis was done using cleared and double-stained specimens representing 21 species of Cynolebias. This analysis showed that some of the characters previously used to diagnose this genus and some of the species are polymorphic. Osteologically, Cynolebias can be diagnosed by the following synapomorphies: (1) triangular-shaped parietal, (2) vomer positioned ventral to the parasphenoid, (3) long ventral process of the dentary, (4) teeth on fourth ceratobranchial, and (5) teeth on first epibranchial. In addition, characters that help …


Translation Of Random Transcripts Generated By Tdt: Potential Use In Polysome Peptide Libraries, Michael Lane Spencer Jul 1998

Translation Of Random Transcripts Generated By Tdt: Potential Use In Polysome Peptide Libraries, Michael Lane Spencer

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science in Biology by Michael Lane Spencer on July 22, 1998.


The Biology Of Xenopus By R. C. Tinsley And H. C. Kobel, Rafael O. De Sá May 1998

The Biology Of Xenopus By R. C. Tinsley And H. C. Kobel, Rafael O. De Sá

Biology Faculty Publications

The Biology of Xenopus presents a summary of current knowledge about a single genus resulting from a symposium held at the Zoological Society of London in September 1992. This approach to summarizing available information has also been taken for other taxa, such as Atelopus (Lotters, 1996). However, the task of compiling data for Xenopus is enormous relative to any other amphibian group, because Xenopus laevis has become a model system for molecular and development research (Cannatella and de Sa, 1993). Unfortunately, most of our knowledge of Xenopus is biased toward this single species. There are about 20 recognized species of …


Chondrocranial Morphology Of Leptodactylus Larvae (Leptodactylidae: Leptodactylinae): Its Utility In Phylogenetic Reconstruction, Peter M. Larson, Rafael O. De Sá Jan 1998

Chondrocranial Morphology Of Leptodactylus Larvae (Leptodactylidae: Leptodactylinae): Its Utility In Phylogenetic Reconstruction, Peter M. Larson, Rafael O. De Sá

Biology Faculty Publications

Chondrocranial morphology of leptodactylid frogs is scarcely known and has not been completely described for any species of Leptodactylus. We describe the diversity of chondrocranial morphology in the genus Leptodactylus based on the analysis of 22 species, representing the four species groups: the fuscus Group, ocellatus Group, melanonotus Group, and pentadactylus Group. Furthermore, 26 characters are identified and used in a phylogenetic analysis. The phylogenetic analysis using Physalaemus, Crossodactylus, and Hylodes as outgroups suggests two monophyletic clades within Leptodactylus: the melanonotus-ocellatus clade and the pentadactylusfuscus clade. However, it does not support the monophyly of the species groups as currently recognized …


Report Of Significant Findings--Las Vegas Bay/Boulder Basin Investigations, James F. Labounty, Michael Horn, Bureau Of Reclamation Apr 1996

Report Of Significant Findings--Las Vegas Bay/Boulder Basin Investigations, James F. Labounty, Michael Horn, Bureau Of Reclamation

Publications (WR)

Field sampling was carried out between 0830 and 1500 beginning at the confluence of Las Vegas Wash and the Inner Las Vegas Bay. Ten (10) locations were sampled, each in a similar manner. Locations of sampling stations are in line from the Wash-Bay confluence to a point midway between Saddle and Black Islands. In addition, sampling was done at a location midway between Sentinel Island and the base of Fortification Hill, and at the buoy line in front of Hoover Dam. Sampling stations are labeled from LV01, at Wash-Bay confluence, to LV17 at Hoover Dam. A significant data collection point …


Cascading Disturbances In Florida Bay, Usa: Cyanobacteria Blooms, Sponge Mortality, And Implications For Juvenile Spiny Lobsters Panulirus Argus, Mark J. Butler Iv, John H. Hunt, William F. Herrnkind, Michael J. Childress, Rodney Bertelsen, William Sharp, Thomas Matthews, Jennifer M. Field, Harold G. Marshall Dec 1995

Cascading Disturbances In Florida Bay, Usa: Cyanobacteria Blooms, Sponge Mortality, And Implications For Juvenile Spiny Lobsters Panulirus Argus, Mark J. Butler Iv, John H. Hunt, William F. Herrnkind, Michael J. Childress, Rodney Bertelsen, William Sharp, Thomas Matthews, Jennifer M. Field, Harold G. Marshall

Biological Sciences Faculty Publications

Florida Bay, the shallow lagoon separating mainland Florida and the Florida Keys, USA, is experiencing an unprecedented series of ecological disturbances. In 1991, following reports of other ecosystem perturbations, we observed widespread and persistent blooms of cyanobacteria that coincided with the decimation of sponge communities over hundreds of square kilometers. Juvenile Caribbean spiny lobsters Panulirus argus, among other animals, rely on sponges for shelter; the impact of sponge loss on the abundance of lobsters and their use of shelter, in particular, has been dramatic. The loss of sponges on 27 experimental sites in hard bottom habitat in central Florida Bay …


The Distribution And Occurrence Of Aerobic Heterotrophic Antimicrobic-Producing Bacteria Isolated From The Lower Chesapeake Bay, Linda Lea Gilmer Jan 1993

The Distribution And Occurrence Of Aerobic Heterotrophic Antimicrobic-Producing Bacteria Isolated From The Lower Chesapeake Bay, Linda Lea Gilmer

Biological Sciences Theses & Dissertations

Three different estuarine microenvironments in the lower Chesapeake Bay were investigated for the occurrence and geographical distribution of antimicrobic-producing bacteria. Samples were taken from the water column, fish skin, and algal surfaces. A total of 1472 bacterial isolates were assayed for antimicrobial activity against fungal, Gram-negative and Gram-positive bacterial test organisms. Of the total bacterial isolates assayed, 5. 2% were active antimicrobic producers. Algal surf aces were shown to have a higher incidence of antimicrobic-producing bacteria than the water column or fish skin. No antimicrobic activity was demonstrated by bacteria isolated from the flounder fish skin. The majority of the …


Vertical Distribution Of Phytoplankton Populations Along The Northeastern Continental Shelf Margin Of The United States, Bruce Burwell Wagoner Oct 1988

Vertical Distribution Of Phytoplankton Populations Along The Northeastern Continental Shelf Margin Of The United States, Bruce Burwell Wagoner

Biological Sciences Theses & Dissertations

A study of phytoplankton vertical distribution at six stations along the northeast continental shelf of the United States was conducted in April 1984.

A total of 168 taxa were identified from nine phylogenetic groups collected at depths up to 150 m. Highest cell concentrations and cell volumes were in the upper 30 m. Greatest cell concentrations were produced by diatoms and a pico-nanoplankton component, with cell volumes mainly the product of diatoms and dinoflagellates. A high degree of variability was observed between phylogenetic groups within each station, but less variability was noted for phylogenetic categories at different stations.

Little difference …


Seasonal Phytoplankton Assemblages In The Nansemond River, Virginia, Cindy Eleanor Shomers Jul 1988

Seasonal Phytoplankton Assemblages In The Nansemond River, Virginia, Cindy Eleanor Shomers

Biological Sciences Theses & Dissertations

A monthly phytoplankton study was conducted on the Nansemond River from November 1984 to October 1985. Light microscopy was utilized to characterize the resident populations, their cell concentrations and to provide a general comparison to other regional studies of river systems considered more polluted. The results divided the flora into two major categories. The first group was a pico-nanoplankton component composed of Cyanobacteria and Chlorophycean cells 1-10 um in diameter. The second group was a microplankton assemblage of Bacillariophyceae, Dinophyceae, Cryptophyceae, Chlorophyceae, Cyanobacteria and Euglenophyceae. The pico-nanoplankton had a unimodal abundance pattern with peak concentrations occurring in spring. The microplankton …


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 …


Can We Guarantee The Safety Of Genetically Engineered Organisms In The Environment?, Kathleen H. Keeler, Frances E. Sharples Jan 1988

Can We Guarantee The Safety Of Genetically Engineered Organisms In The Environment?, Kathleen H. Keeler, Frances E. Sharples

School of Biological Sciences: Faculty Publications

Can we guarantee the safety of genetically engineered organisms in the environment? To anticipate my remarks, the answer to the title question is “No, we cannot guarantee the safety of genetically engineered organisms released into the environment.” Indeed, it is a tenet of the scientific method that nothing can be proved, only disproved. Thus, we can never show that a release will be safe. We could only show that it would be unsafe, if that were the case. However, if the question is posed differently, for example, can we safely release genetically engineered organisms into the environment?, the answer is …


An Annual Study Of Phytoplankton Composition And Associated Environmental Conditions Of Lake Trashmore, Virginia Beach, Virginia, Seba B. Sheavly Jul 1987

An Annual Study Of Phytoplankton Composition And Associated Environmental Conditions Of Lake Trashmore, Virginia Beach, Virginia, Seba B. Sheavly

Biological Sciences Theses & Dissertations

A 12 month study of Lake Trashmore was conducted on phytoplankton composition, inorganic nutrients and their seasonal associations. The dominant phytoplankton groups observed were diatoms, chlorophyceans and cyanobacteria. Phytoplankton assemblage patterns were coupled with pH, temperature, dissolved oxygen, nitrites and silicates. Diatoms dominated during periods of high nutrient concentrations, cooler temperatures and an unstable water column. Cyanobacteria forms dominated during periods of warmer temperatures, higher pH and decreased nitrogen and dissolved oxygen concentrations. A seasonal community shift occurred from cyanobacterial dominance to chlorophycean dominance when pH levels decreased. The lake is eutrophic based on indices of chlorophyll a concentrations, transparency …


Benthic Diatom Community Dynamics In The Colorado River: Interactive Effects Of Periodic Dessication And Current Regime, Christopher Gerard Peterson Dec 1984

Benthic Diatom Community Dynamics In The Colorado River: Interactive Effects Of Periodic Dessication And Current Regime, Christopher Gerard Peterson

Publications (WR)

The response to periodic desiccation of periphyton communities developed in eddy environments or in areas exposed to variable, direct current was examined. Algal communities were incubated on clay tiles for between 2 and 12 weeks in the Colorado River, directly below Hoover Dam from October, 1983 - January, 1984. Mean daily discharge from the dam decreased over this period. To assess the influence of these discharge changes on community dynamics, samples collected over the first 12 weeks of the investigation were compared to samples of the same age collected over the final 8 weeks.

The small diatom taxon Achnahthes spp …


Seasonal And Spatial Heterogeneity In The Limnetic Zooplankton Community Of Lake Mead, Gene Robert Wilde May 1984

Seasonal And Spatial Heterogeneity In The Limnetic Zooplankton Community Of Lake Mead, Gene Robert Wilde

Publications (WR)

Zooplankton samples collected from throughout Lake Mead, in 1981-1982, demonstrate the presence of a statistically significant seasonal and spatial heterogeneity in zooplankton densities. Seasonally, the major zooplankton groups were most abundant in the spring and fall, coincident with maxima in chlorophyll-a concentrations. Successions among the various rotifers, cladocerans and copepods present in the reservoir were influenced by food availability, diapause, predation by planktivorous fish and, possibly, water temperatures. Spatial heterogeneity in zooplankton densities was unrelated to water temperature, pH, conductivity and dissolved oxygen concentrations, but was related to the abundance of phytoplankton (chlorophyll-a concentrations) and fish. Statistical analyses indicate that …


Las Vegas Wash Multispectral Scanner Survey, T. H. Mace, M. V. Olsen, Environmental Protection Agency Feb 1984

Las Vegas Wash Multispectral Scanner Survey, T. H. Mace, M. V. Olsen, Environmental Protection Agency

Publications (WR)

At the request of the U.S. Bureau of Reclamation, Boulder City, Nevada, the U.S. Environmental Protection Agency's Environmental Monitoring Systems Laboratory at Las Vegas collected multispectral scanner imagery of Las Vegas Wash on October 1, 1982. A combined maximum likelihood classification and editing procedure was used to classify the multispectral scanner imagery into 12 categories of land cover. The classification identified four categories of marsh vegetation, one category of riparian, two categories of mixed scrub, and two desert categories. Turbid water and cultivated land formed an "other" category. Area tabulations were formed by georeferencing the classification to the Universal Transverse …


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 …


A Limnological Study Of 43 Selected Maine Lakes, Derrill J. Cowing, Matthew Scott Jan 1980

A Limnological Study Of 43 Selected Maine Lakes, Derrill J. Cowing, Matthew Scott

Maine Collection

A Limnological Study of 43 Selected Maine Lakes

by Derrill J. Cowing and Matthew Scott

U.S. Geological Survey : Water-Resources Investigations 80-69

Prepared in cooperation with the Maine Department of Environmental Protection

U.S. Geological Survey, 26 Ganneston Drive, August, Maine 04330


Interactions In Lambdoid Bacteriophage Populations, Bruce Edward Mitchell Jan 1978

Interactions In Lambdoid Bacteriophage Populations, Bruce Edward Mitchell

Masters Theses

The lambdoid bacteriophages are ideal subjects for the study of populational interactions at the molecular level because they do not mutually exclude one another in mixed infection of the same host cell. Previous work done in this laboratory using the lambdoid phage pairs λ-434 hy mi and λ-80 have demonstrated a density-dependent reduction in progeny yield per infected cell (burst size) as a function of increasing multiplicity of infection (m.o.i.). The λ cI gene which codes for the repress or molecule has been demonstrated to be the cause of the interaction in the λ-434 hy mi phage pair. …


The Biology Of Coprinus Radians, Ozonium, Oidium, And Their Interrelationships, Thomas J. Fahey Dec 1977

The Biology Of Coprinus Radians, Ozonium, Oidium, And Their Interrelationships, Thomas J. Fahey

All-Inclusive List of Electronic Theses and Dissertations

The pleomorphism of Coprinus radians was studied. The three distinct growth forms--sporophore, oidial stage, and ozonium stage--were examined in relation to ultrastructure, morphology and development. Scanning and transmission electron microscopy are correlated with photomicrographs of developmental stages. Development of the oidia and of the sporophore are of particular interest. The multinucleate oidia develop quite differently from oidia as generally described for Basidiomycete imperfect stages. Development of the oidia of this Coprinus is holoblastic and sympodial. The mushroom primordia are differentiated internally into gill, cap, and stipe hyphae while only l-2mm in diameter. At this stage they look superficially like sclerotial …


A Review Of The Limnology Of And Water Quality Standards For Lake Mead, Charles R. Goldman Oct 1976

A Review Of The Limnology Of And Water Quality Standards For Lake Mead, Charles R. Goldman

Publications (WR)

1. The waters of Las Vegas Bay, a heavily utilized recreational resource, receive discharges from a variety of municipal and industrial waste sources. The U.S. Environmental Protection Agency has determined, on the basis of numerous studies, that the present water quality violates state and federal standards and constitutes a public nuisance. Consultants have advised the Sewage and Wastewater Advisory Committee that rapid abatement of the alleged pollution conditions can be achieved by an advanced wastewater treatment (AWT) plant.

2. The major problems in Las Vegas Bay are an objectionable water color, excessive turbidity, noxious odors, and oxygen depletion in certain …


Report On Wastewater Disposal To Board Of County Commissioners, Clark County Nevada, Clair N. Sawyer Oct 1976

Report On Wastewater Disposal To Board Of County Commissioners, Clark County Nevada, Clair N. Sawyer

Publications (WR)

This report is concerned with the management of waste-waters and subsurface drainage from the City of Las Vegas and its environs and the BMI complex, all in Clark County, Nevada. The prime objective is to recommend a plan of action which will utilize the natural resources of the area in the least costly manner and still protect Lake Mead for recreational purposes and use as a public water supply, At this writing, conditions in the upper Las Vegas arm of Boulder Basin are quite unsatisfactory for some recreational purposes due to the extensive blooms of algae which develop. Experience at …


Phomopsis : The Causal Fungus Of Lupinosis, P Mcr Wood, A. G. P. Brown Jan 1975

Phomopsis : The Causal Fungus Of Lupinosis, P Mcr Wood, A. G. P. Brown

Journal of the Department of Agriculture, Western Australia, Series 4

It is now well known that lupinosis of sheep and cattle follows ingestion of lupin stubble colonised by the fungus Phomopsis rossiana. The fungus infects green lupins but persists on the stubble and under certain conditions apparently produces a toxin which causes the disease.

As Phomopsis is now widespread on lupins in Western Australia its ecology has been studied in detail as a basis for possible control measures.

This article outlines what is known so far of the disease and its control.


A Statistical Approach To The Study Of The Ecosystems Of Seven Ponds In East-Central Illinois, Gregory Lee Orr Jan 1975

A Statistical Approach To The Study Of The Ecosystems Of Seven Ponds In East-Central Illinois, Gregory Lee Orr

Masters Theses

Gross primary productivity, heterotrophic bacterial numbers, and net phytoplankton densities of seven ponds in Coles County, Illinois, were studied in relation to physical, chemical, and biological habitat variables (light intensity and duration, turbidity, water temperature, pH, dissolved oxygen, sulfur, nitrogen, phosphorus, production, bacteria, and phytoplankton). Ten observations were made for each pond (except where otherwise noted) from 17 June through 25 August 1974. Stepwise multiple linear regression analyses of the data were used in order to determine those environmental factors which were important in predicting (i.e., significantly correlated with) bacterial and phytoplankton densities, and production. A multiple linear regression equation …


Karyotype Of Geomys Pinetis (Mammalia: Geomyidae), With A Discussion Of The Chromosomal Relationships Within The Genus, S. L. Williams, Hugh H. Genoways Jan 1975

Karyotype Of Geomys Pinetis (Mammalia: Geomyidae), With A Discussion Of The Chromosomal Relationships Within The Genus, S. L. Williams, Hugh H. Genoways

University of Nebraska State Museum: Mammalogy Papers

Summary. Four of the five subspecies of Geomys pinetis were karyotyped. All specimens examined had a diploid number of 42 and a fundamental number of 80. This karyotype was compared with the described karyotypes of other species of Geomys and was considered to be derived from an ancestoral form having a karyotype of about 70 acrocentric elements.