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Articles 38371 - 38400 of 39114
Full-Text Articles in Life Sciences
The Effects Of Laminar Air-Flow On The Viability Of Microorganisms, Royce M. Brockett
The Effects Of Laminar Air-Flow On The Viability Of Microorganisms, Royce M. Brockett
Biology ETDs
The effect of laminar air-flow on the viability of microorganism was investigated. The related factors of inoculum size and carrier medium were also studied. The test surface used in this study was stainless steel. Microorganisms were placed on the test strips and exposed to laminar air-flow. After the chosen exposure period the test strips were placed in a sterile petri dish and covered with tryptic soy agar. Viable counts were taken as the number of colonies developing after incubation. Viable counts obtained with this direct plating method were briefly compared with viable counts obtained by two other assay methods.
It …
A Study Of The Flora Of The Cochiti And Bland Canyons Of The Jemez Mountains., Charles W. Robertson
A Study Of The Flora Of The Cochiti And Bland Canyons Of The Jemez Mountains., Charles W. Robertson
Biology ETDs
Cochiti and Bland canyons are adjacent steep-walled canyons in the Jemez Mountains. The canyons range in elevation from 6,000-8,500 ft and open into the Rio Grande Valley. The former has permanent water, the latter does not. Cochiti Canyon is constricted at its mouth and widest near its head.
The Canadian, Transition and upper Sonoran life zones are represented in the study area. Due to the variety of exposures these zones seldom occur exclusively over large areas. The varied topography, volcanic outcroppings, disturbance by man, and water supply all contribute to the extreme diversity and variety of the flora. The flora …
The Effects Of Radiation And Temperature Stress On An Aquatic Ecosystem, Gene L. Samsel Jr.
The Effects Of Radiation And Temperature Stress On An Aquatic Ecosystem, Gene L. Samsel Jr.
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 Gene L. Samsel, Jr. on May 14, 1968.
Seasonal Changes In Fat Content Of The Big Brown Bat, Eptesicus Fuscus, Neil S. Weber
Seasonal Changes In Fat Content Of The Big Brown Bat, Eptesicus Fuscus, Neil S. Weber
Biology ETDs
Bats were collected from 22 April 1967 through 30 September 1967 from various localities in New Mexico. Eighty-one individuals were desiccated in a vacuum desiccator, after which total body fat was extracted with 95% ethanol and petroleum ether. Data are presented on total body water and total body fat. Total body fat increases from April to September. Comparison of males and females reveals that both sexes have the greatest increase in body fat sometime in September.
A Serological Estimate Of Monzygotic Twinning In Sheep, William D. Stansfield
A Serological Estimate Of Monzygotic Twinning In Sheep, William D. Stansfield
Biological Sciences
No abstract provided.
Marine Fungi Of Iceland: A Preliminary Account Of Ascomycetes, A. R. Cavaliere
Marine Fungi Of Iceland: A Preliminary Account Of Ascomycetes, A. R. Cavaliere
Biology Faculty Publications
This paper reports, for the first time, 25 species of marine pyrenomycetes from Icelandic waters. Taxonomic notes are included for certain species.
Surtsey, a submarine volcanic upthrust off the south coast of Iceland (Thorarinsson, 1967), is a current center for cooperative geophysical, geochemical, and biological investigations on an international scale. The mycological portion of the total biological research effort of the Surtsey project has emphasized a survey of the marine and freshwater mycoflora on the mainland of Iceland itself as a necessary prerequisite to ecological studies on Surtsey. With the exception of two reports on aquatic phycomycetes (Larsen, 1931, and …
Systemic Studies Of The Genus Gila (Cyprinidae) Of The Colorado River Basin, Paul Bernard Holden
Systemic Studies Of The Genus Gila (Cyprinidae) Of The Colorado River Basin, Paul Bernard Holden
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Three Hundred and nine specimens of Gila from the Colorado River basin were studied. A form of numerical taxonomy, taximetrics, was used to help classify the specimens. The data from these fish indicate that many of the present hypotheses concerning their taxonomy are not valid. The concept of ecosubspecies or ecological subspecies does not fit the Colorado basin Gila. The roundtail and bonytail chubs, G. robusta Baird and Girard and G. elegans Baird and Girard respectively, currently treated as subspecies, are well separated morphologically, ecologically and reproductively and therefore are better considered two valid species. The relationship between G. …
Daily Nest Opening And Closing Of The Ant Pogonomyrmex Californicus, Lynn R. Heath
Daily Nest Opening And Closing Of The Ant Pogonomyrmex Californicus, Lynn R. Heath
Loma Linda University Electronic Theses, Dissertations & Projects
In a study of timing in this ant ten of the twelve nests which were observed opened synchronously in the morning and closed in the evening. However, one was never seen to close and another closed during the day and stayed open at night.
A seasonal progression was shown by later opening times and earlier closing times. Opening and closing temperatures at the surface of the ground and three inches deep showed no seasonal progression.
In most cases the days when the nests opened the earliest the temperatures at opening time were the highest.
Soon after nests had closed they …
Floral Morphology And Phylogeny In The Hydrocharitaceae, Robert B. Kaul
Floral Morphology And Phylogeny In The Hydrocharitaceae, Robert B. Kaul
School of Biological Sciences: Faculty Publications
The vascular anatomy of 13 of the 15 genera of the Hydrocharitaceae has been studied, and certain aspects of floral morphology are considered. The flowers of the family show a broad range of specialized structures combined with primitive characteristics. The origin of paired and single stamens is interpreted as probable modifications of fascicled stamens. Extreme reduction in the androecium is shown for several genera. Tendencies toward reduction and fusion within the gynoecium are pronounced. Most genera are at least slightly syncarpous, but a few are apocarpous. The inferior ovary is appendicular in nature, with some genera exhibiting more complete fusion …
Floral Development And Vasculature In Hydrocleis Nymphoides (Butomaceae), Robert B. Kaul
Floral Development And Vasculature In Hydrocleis Nymphoides (Butomaceae), Robert B. Kaul
School of Biological Sciences: Faculty Publications
The flower of Hydrocleis nymphoides consists of three sepals which arise in spiral succession, three simultaneously arising petals, numerous stamens and staminodia which arise in centrifugal order, and six carpels. A residual apex remains at maturity. The first-formed members of the androecium are stamens and the later-formed members are staminodia which develop below the stamens and which become outwardly displaced during expansion of the receptacle. The androecium is supplied by branching vascular trunk bundles. The carpels are completely open but the ventral margins are slightly conduplicately appressed basally. A single dorsal bundle provides the stigmatic area with vascular tissue, and …
Acid Phosphate Activity In Tobacco Mosaic Virus Susceptible And Hypersensitive Varieties Of Burley Tobacco, David J. Saxon
Acid Phosphate Activity In Tobacco Mosaic Virus Susceptible And Hypersensitive Varieties Of Burley Tobacco, David J. Saxon
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 David J. Saxon on January 23, 1968.
Studies In Locomotion And Anatomy Of Scombroid Fishes, Harry L. Fierstine, Vladimir Walters
Studies In Locomotion And Anatomy Of Scombroid Fishes, Harry L. Fierstine, Vladimir Walters
Biological Sciences
Acceleration rates, analyses of body movements, and pertinent anatomical features are given for various members of the Scombridae, Istiophoridae, and Xiphiidae and are discussed in light of the modern work on smaller freshwater teleosts and marine cetaceans.
Acceleration values up to 43.1 m/sec2 are given for Thunnus albacares and Acanthocybium solanderi. Nearly 100% of the propulsive thrust comes from the caudal fin. There are two main intervertebral joints which are concerned with locomotion, a pre-peduncular and a post-peduncular joint with the body and peduncle held almost stiff, a condition similar to that described for marine cetaceans. The caudal …
Biological Aspects Of Heat Pollution, Theodore Olson
Biological Aspects Of Heat Pollution, Theodore Olson
Journal of the Minnesota Academy of Science
The importance of temperature as an environmental factor has long been recognized by the ecologist, and its special impact upon the aquatic ecosystem has been of interest to aquatic biologists since they first began to observe interactions between living things and the physical environment. Interest in water temperatures as an environmental factor has recently become more widespread; and one aspect of the phenomenon, namely "thermal pollution," has attracted special attention.
Some Aspects Of The Symbionts Of Cassiopeia Frondosa, Dolores Ahles O.S.F.
Some Aspects Of The Symbionts Of Cassiopeia Frondosa, Dolores Ahles O.S.F.
Journal of the Minnesota Academy of Science
Symbiodinium microadriaticum were found localized in the mesoglea of Cassiopeia, the upside-down jellyfish. Axenic cultures of the symbiont were produced, utilizing chemically defined media. Studies of the life cycle established the presence of isogametes which had previously been postulated. Reactions to various bands of the spectrum were noted, and tolerance tests for survival in darkness and under temperature stress were carried out. Nutritional experiments established nitrates as the best nitrogen source and verified the fact that vitamins B12 and Thiamine, though not essential far life, hove a stimulating effect on the growth and motility of these zooxanthellae.
Distribution And Abundance Of Molluscs In A Fresh Water Environment, Peter Moyle, James Bacon
Distribution And Abundance Of Molluscs In A Fresh Water Environment, Peter Moyle, James Bacon
Journal of the Minnesota Academy of Science
The molluscs of o northwestern Minnesota lake were sampled using transects, a sampling frame, and SCUBA. The species sampled were: Amnicola limosa, Valvata tricarinata, Gyraulus parvus, Physa cf. P. gyrina, Helisoma anceps, H. campanulata, Promenetus exacuous, Ferrissia parallela, Anodonta marginata, Lampsilis siliquoidea, and Sphaerium cf. S. striatum. The unionid clams, the adult Helisoma spp. and the Physa adults were associated with the absence of aquatic vegetation. Distinct associations of snail species were found with each plant association: G. parvus and V. tricarinata with the deep water Nitella opaca association, A. limosa and V. tricarinata with the mid-depth mixed macrophyte association, …
Characteristics Of Four Marl Lakes As Related To Biological Productivity, J. E. Maloney, John Dobie, John B. Moyle
Characteristics Of Four Marl Lakes As Related To Biological Productivity, J. E. Maloney, John Dobie, John B. Moyle
Journal of the Minnesota Academy of Science
Physical and chemical characteristics of four dimictic eutrophic lakes of northcentral Minnesota with marl deposits are discussed in relation to production of invertebrate animals (benthos and plankton) that are the basic food of fish . Two of the lakes have a history as "productive" fish lakes and the other two as "problem" fish lakes. The "productive" lakes, as a type, have a larger surface area, a longer shallow-water littoral shelf, and a lower proportion of marly soils in the littoral zone than do the "problem" lakes. The standing crop of invertebrates was about twice as great per habitat unit in …
Invertebrate Fauna And Environment Of Deposition Of The Niobrara Formation (Cretaceous) Of Kansas, Halsey W. Miller
Invertebrate Fauna And Environment Of Deposition Of The Niobrara Formation (Cretaceous) Of Kansas, Halsey W. Miller
Fort Hays Studies Series
This paper reevaluates, and where desirable, synonymizes species. Previously unrecorded species are described and illustrated. The environment of the Niobrara Formation in Kansas is described. The author collected specimens in Scott, Logan, Gove, Trego, Rooks and Phillips Counties, Kansas.
Billfish Remains From Southern California With Remarks On The Importance Of The Predentary Bone, Harry L. Fierstine, Shelton P. Applegate
Billfish Remains From Southern California With Remarks On The Importance Of The Predentary Bone, Harry L. Fierstine, Shelton P. Applegate
Biological Sciences
No abstract provided.
Renin Granularity In The Mouse Kidney, R. Williams Soller
Renin Granularity In The Mouse Kidney, R. Williams Soller
Senior Scholar Papers
Briefly. the rennin-angiotensin-aldosterone triangle can be thou ht of as a regulator of renal perfusion. Renin, released by the kidney in response to any threat in its perfusion n, acts on its substrate to produce angiotensin I, a mild vasoconstrictor which by means of plasma converting enzymes secretes angiotensint II. This latter product not only stimulates aldosterone output by the adrenals, but also supports the animals’ blood pressure. With aldosterone binding at the distal tubules in the kidney and this causing increased sodium retention, restoration of renal perfusion occurs – a phenomenon which shuts off the original signal for rennin …
Flights Of The Ant Polyergus Lucidus Mayr, Mary Talbot
Flights Of The Ant Polyergus Lucidus Mayr, Mary Talbot
Faculty Scholarship
Flights of ants at the Edwin S. George Reserve, Livingston County, Michigan, have been studied over a number of years (Talbot 956, I959, 963, I964, 966, and Kannowski 959a, 959b). This paper is another in the flight series and concerns the slave-making ant, Polyergus lucidus Mayr.
A Biosystematic Study Of Taenidia And Pseudotaenidia (Umbelliferae), Roland Lee Guthrie
A Biosystematic Study Of Taenidia And Pseudotaenidia (Umbelliferae), Roland Lee Guthrie
Graduate Theses, Dissertations, and Problem Reports (ETD)
The primary research objectives of this work are to investigate and to evaluate the phylogenetic relationship between two genera of the Umbelliferae and, by means of the study of these genera, to evaluate in general the principal characteristics that are used to classify the Umbelliferae along phylogenetic lines.
An Ecological Study Of Notoplana Acticola, A Polyclad Flatworm, In A Rocky Intertidal Habitat On The North Central California Coast, Alan Bradley Thum
An Ecological Study Of Notoplana Acticola, A Polyclad Flatworm, In A Rocky Intertidal Habitat On The North Central California Coast, Alan Bradley Thum
University of the Pacific Theses and Dissertations
The taxonomy of the polyclad flatworms is fairly well-known and some attention has been given to study of their physiology. Investigations of an ecological nature, however, are scarce; in fact, no ecological studies have been made on the Pacific Coast of North America. Else- where, Pearse and Wharton (1938) investigated the general ecology of Stylochus frontalis, associated with oysters on the coasts of Florida, and occasional notes have appeared, reporting on polyclads as predators on oysters and barnacles (Book, 1925: Wolke, 1954; Loosanoff, 1956: Skerman,1960)
Seasonal Gonadal Changes Of Adult Oviparous Oysters In Tomales Bay, Carl John Berg
Seasonal Gonadal Changes Of Adult Oviparous Oysters In Tomales Bay, Carl John Berg
University of the Pacific Theses and Dissertations
Two species of oviparous oysters, Crassostrea virginica (Gmelin, 1790), the Eastern oyster, and Crassostrea gigas (Thunbert, 1793), the Japanese oyster, were introduced into Tomales Bay, California, for commercial purposes. Because these oysters do not propagate in Tomales Bay, new shipments of adult oysters or oyster spat must be periodically sent from the east coast of the United States or from Japan. It is the purpose of this study to compare the seasonal gonadal changes which occur in the two species of adult oysters in Tomales Bay with one another, and to compare them with the seasonal gonadal changes which occur …
Oxygen Uptake And Thyroid Activity During Amphibian Metamorphosis, Susan Ann Foster
Oxygen Uptake And Thyroid Activity During Amphibian Metamorphosis, Susan Ann Foster
University of the Pacific Theses and Dissertations
Oxygen consumption can most readily be related to wet weight. However, the weight of a tadpole increases so long as it is feeding, then decreases during final non-feeding stages. Oxygen uptake may also be related to dry weight, but dry weight increases significantly from early tadpole stages to adult (Funkhouser and Mills, in press). There is change in one factor at the same time the change in the the other factor is in the opposite direction. Total nitrogen content may be used as an index of the metabolizing tissue, but is subject to the same criticism as dry weight (Moore, …
Effects Of Hypothermia And Saline Injection Of Cesium-137 And Sodium-22 Metabolism In White Rats, Glenn Michael Dempsey
Effects Of Hypothermia And Saline Injection Of Cesium-137 And Sodium-22 Metabolism In White Rats, Glenn Michael Dempsey
Biology ETDs
The excretion rates and distribution of cesium-137 and sodium-22 were studied in white rats exposed to cold or over-hydration, or both.
A single intraperitoneal injection of cesium-137 or sodium-22 was administered to rats housed in metabolic cages. Rate of isotope excretion was determined by daily measurements of urine, feces, and the whole animal with a gamma scintillation spectrometer.
In one study rats were injected intraperitoneally with saline solution equivalent to 10% of the body weight one hour after having been injected with cesium-137. After 23 hours the rats were sacrificed and individual tissue counts were taken to be compared with …
Structure Of The Trpc Cistron Specifying Indoleglycerol Phosphate Synthetase, And Its Localization In The Tryptophan Operon Of Escherichia Coli, Oliver H. Smith
Structure Of The Trpc Cistron Specifying Indoleglycerol Phosphate Synthetase, And Its Localization In The Tryptophan Operon Of Escherichia Coli, Oliver H. Smith
Biological Sciences Faculty Research and Publications
No abstract provided.
Geographic Variation In The Ord's Kangaroo Rat In The Upper Rio Grande Valley, Keith B. Grisham
Geographic Variation In The Ord's Kangaroo Rat In The Upper Rio Grande Valley, Keith B. Grisham
Biology ETDs
The Ord's Kangaroo Rat has the most extensive geographic range of any Dipodonmys species, extending from southern Canada to within 20 degrees north of the equator on the Mexican Plateau. Testifying to intraspecific variation throughout this range, the most recent revision of subspecies (Setzer, 1949) liststhirty-five subspecies of Dipodomys ordii. This kangaroo rat is found throughout the Rio Grande Valley in suitable habitat and extends as far north as Saguache in the San Luis Valley of Colorado. I am interested in the geographic variation found in the upper Rio Grande Valley, here defined as that portion of the valley from …
Studies On The Effect Of Aeration On Spore Germination, Mary Jane Wilson
Studies On The Effect Of Aeration On Spore Germination, Mary Jane Wilson
Biology ETDs
Bacterial spores are refractile bodies formed within vegetative cells, generally of the genera Bacillus and Clostridium. Spores have also been reported in certain cocci, spirilla, and Azotobacter, although their kinship to spores of Bocillus and Clostridium is not well understood (Robinow, 1960). The spore is characterized by its refractility, impermeability to basic dyes, and increased resistance to heat, chemicals, radiation (Vinter, 1961), enzymes, and freezing (Murrell, 1961b). The spore is also well defined by its mode of formation, its peculiar structure, and its unique chemical composition.
The possibility that biological contamination in the form of spores might seriously confuse the …
A Microbiological Evaluation Of A Laminar Down-Flow Hood, Robert Henry Staat
A Microbiological Evaluation Of A Laminar Down-Flow Hood, Robert Henry Staat
Biology ETDs
An Envirco Model DF-400 laminar down flow hood with an exhaust HEPA filter adaptation was tested for its efficiency by using Bacillus subtilis var. niger as an indicator organism. The experimental emphasis was on the bacterial spore penetration of the frontal barrier and of the exhaust system. Interior and exterior challenges were made. The interior challenge utilized two heights and progressed from the front of the hood to the rear. Bacterial migration on the hood surface, surface impingement, ambient air conditions, and exhaust air were checked. All ambient air sampling was done with Andersen samplers. The exterior challenge consisted of …
The Effects Of Coelomic Fluid And Isotonic Homogenates Of The Freshwater Bryozoan Lophopodella Carteri On Fish Tissue, Roger H. Meacham
The Effects Of Coelomic Fluid And Isotonic Homogenates Of The Freshwater Bryozoan Lophopodella Carteri On Fish Tissue, Roger H. Meacham
Master's Theses
A study was made to determine if fish tissue was poisoned by the coelomic fluid extracted from the common coelomic cavity of colonies of the freshwater bryozoan, Lophopodella carteri (Hyatt). Additional studies were made of fish tissues, in vivo and in vitro, when exposed to homogenates of crushed colonies of L. carteri in isotonic medium.
The fish exposed to the coelomic fluid did not show any signs of respiratory distress and therefore the poisonous quality must be located elsewhere in the bryozoan. The homogenates were determined to be poisonous as fishes exposed to a 3.0% solution were killed within an …