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Articles 451 - 480 of 639
Full-Text Articles in Biology
Vascularization In Seedlings Of Four Species Of Opuntia, Benjamin Lee Pilcher
Vascularization In Seedlings Of Four Species Of Opuntia, Benjamin Lee Pilcher
Biology ETDs
No abstract provided.
The Ecological Distribution Of Lizards In The Blue River Valley, Terence P. Boyle
The Ecological Distribution Of Lizards In The Blue River Valley, Terence P. Boyle
Biology ETDs
The problem presented is the ecological distribution of seven species of lizards in the Blue River Valley of Greenlee County, Arizona. Field work was done May to July, 1967 and 1968 in the mountains, and July to September 1968 in the valley. Lizards were collected with a hand-gun and are preserved in the Museum of Southwestern Biology, Division of Eerpetology, University of New Mexico. A plant collection was made and seven plant communities are described. Seven species of lizards are compared by plant-community affiliation and habitat.
Urosaurus ornatus was the most euryecious species found. It inhabited every plant community where …
The Ecology And Herptiles Of The Rio Hondo And Rio Bonito Valleys, John E. Kimmons
The Ecology And Herptiles Of The Rio Hondo And Rio Bonito Valleys, John E. Kimmons
Biology ETDs
Twenty-two transects were made across the Rio Bonito and Rio Hondo valleys, Lincoln County, New Mexico, to determine the slope of the land, exposure, and elevation for the vegetational associations. The plant associations are the riparian, mesquite-grassland, cholla-grassland, cliff and talus, mountain-mahogany, pinyon-juniper, and hilltop. The elevation of the area ranges from 4,640 to 6,940 feet. The study includes the streams, valley floors, hillsides, and hilltops.
Most of the 314 herptile specimens collected were in the riparian, cliff and talus, and grassland associations. Twenty-four species were collected. Sceloporus poinsetti was frequently collected, providing a range extension for this species.
The …
The Effects Of Solubility On The Deposition And Elimination Of Three Cerium Compounds In Mice Following Exposure By Inhalation, Barbara Nylund Morgan
The Effects Of Solubility On The Deposition And Elimination Of Three Cerium Compounds In Mice Following Exposure By Inhalation, Barbara Nylund Morgan
Biology ETDs
Ce144 is an important radioisotope of cerium because it is formed as the result of uranium fission. Consequently, it is a predominant fission product in a reactor inventory after a period of sustained reactor operation as well as a major isotope released following nuclear accidents. The energy released during a nuclear explosion is sufficient to bond 144Ce to several anionic species depending upon the immediate environment. Among those anions are included citrates, oxides, halides and inorganic debris such as clay particles from earth or structural materials. Because the major route of entry of contaminated materials is by inhalation, it is …
The Effect Of Coxiella Burnetii Parasitism On The Fertile Chieken Egg Injected With Glucose-14c, Oswald G. Baca
The Effect Of Coxiella Burnetii Parasitism On The Fertile Chieken Egg Injected With Glucose-14c, Oswald G. Baca
Biology ETDs
The effect of parasitism by the rickettsia Coxiella burnetii on the chicken embryo was studied by extracting rickettsiae separated from infected yolk sacs and examining the extracts for radioactivity arising from D-glucose-U-14C injected into the embryonated eggs. The rickettsiae were separated from the yolk sacs with a cation exchange resin and differential centrifugation. The purified rickettsiae were then extracted for various components. The extracts 4 were subjected to radioactivity determination with an internal sample liquid scintillation counter. The extracts were also chromatographed and superimposed on X-ray film for radioautography. No significant differences in radioactivity were found be tween …
Effect Of Relative Humidity At 23 C On Egg Eclosion In Two Species Of Pyralid Moths, William P. Morrison
Effect Of Relative Humidity At 23 C On Egg Eclosion In Two Species Of Pyralid Moths, William P. Morrison
Biology ETDs
Desiccation resistance in eggs of the Indian-meal moth, Plodia interpunctella, and the bluegrass webworm, Crambus teterrellus, was compared. Decapitation was used to obtain eggs for humidity studies. In both species decapitated females showed a slightly higher incidence of infertile eggs, as well as of fertile eggs which did not eclose, than occurred in eggs collected from nondecapitated females. Eggs of P. interpunctella are relatively resistant to desiccation. This moth is a pest of stored grains and tends to oviposit in areas of low humidity. In laboratory tests more than 95% of the fertile eggs eclosed at each of the nine …
Aortic Cannulation As An Experimental Tool In ¹³⁷Cs Metabolic Studies, Lyman B. Spaulding
Aortic Cannulation As An Experimental Tool In ¹³⁷Cs Metabolic Studies, Lyman B. Spaulding
Biology ETDs
Tissue accumulations of cesium-137 by the white laboratory rat, Rattus norvegicus, were studied by varying the length of time between isotope introduction and sacrifice, the temperature of the animal, and the route of administration of the radioisotope. Most tissues from animals in the normothermic and hypothermic condition accumulated their major 137Cs component within the first minute of isotope introduction. The temperature of the animal (18 C) was observed to influence tissue accumulation. Hypothermia limited uptake of radiocesium by peripheral tissues but enhanced uptake by internal tissues. Route of administration (i.a. and i.p.) differences were observed for only the heart …
Effects Of The Mutants Brown And Brown-Dominant On Pteridine Content In Drosophila Melanogaster, Donald M. Evans
Effects Of The Mutants Brown And Brown-Dominant On Pteridine Content In Drosophila Melanogaster, Donald M. Evans
Biology ETDs
The pteridine content of a brown, a brown-dominant, and a wild stock of Drosophila melanogaster was studied. The separation by ascending two-dimensional chromatography of the pteridine substances revealed differences in the number and quantity of pteridines present in these stocks. Differences also were found between pteridine content of heterozygotes and the corresponding homozygotes. The dominance and recessiveness, as reflected in eye color, did not extend to the level of pteridine metabolism, and pteridine substances were found in some heterozygotes that were not present in either homozygous parental stock.
The Effects Of Exercise On The Response Of Rats To Air Blast, Kabby Mitchell Jr.
The Effects Of Exercise On The Response Of Rats To Air Blast, Kabby Mitchell Jr.
Biology ETDs
The mortality of rats exposed to the combined effects of air blasts and exhaustive exercise was investigated. Five hundred rats were exposed to sharp rising air blasts of 300 to 400 msec durations in a shock tube after which 250 rats were swum at different times and for varying periods post blast. There were 250 blast controls and 95 swim controls.
In the primary experiment, rats were swum to exhaustion beginning 15 min after exposure to graded levels of air blast. In the three other series of experiments, animals were swum to exhaustion at 5 min after blast; swum to …
131i Metabolism In The Beagle Dog As Affected By Age And Route Of Exposure, Robert E. Foreman
131i Metabolism In The Beagle Dog As Affected By Age And Route Of Exposure, Robert E. Foreman
Biology ETDs
Seven parameters were chosen to characterize131I metabolism in the Beagle, three were derived from the thyroid uptake -retention curve [maximum thyroid uptake, time to 90% maximum uptake, and biological half-life] and four from the two component whole-body131I retention curve [component intercept values, and component half-times]. These parameters were used to compare 131I metabolism in three age groups [6 , 18 , and 48 months], each consisting of six Beagles exposed to a single dose of 131I [ 100-300 µCi] by the inhalation route. An analysis of variance was performed on each parameter in this …
Uptake And Retention Of Tritiated Water By Tissues Of Laboratory Rats And Citellus Lateralis, Gary L. Bintz
Uptake And Retention Of Tritiated Water By Tissues Of Laboratory Rats And Citellus Lateralis, Gary L. Bintz
Biology ETDs
Tritiated water was employed to study selective absorption and retention of water by different tissues of laboratory rats and C. lateralis. Control (hydrated) and water deprived (dehydrated) animals of both species were studied. Tissues analyzed included large tissues capable of water storage (skin, blood, muscle, liver, white fat) and tissues involved in exchange of water with the environment (small intestine, kidney, lung). The data demonstrated considerable variability in tritium contents, both in different tissues of the same animal, and in the same tissues of different animals of the same group. There appeared to be no selective uptake nor retention of …
Forest Survey Of Guadalupe Mountains, Texas, James L. Robinson
Forest Survey Of Guadalupe Mountains, Texas, James L. Robinson
Biology ETDs
A vegetational study of an area of the Guadalupe Mountains, Culberson County, Texas, was made to help evaluate the ecological impact on the area if a national park should be located at this site. The stands of coniferous forest in the study area, completely surrounded by vegetation typical of the Chihuahuan desert, are considered to be remnants of a more extensive coniferous forest during the Late Pleistocene. Thus the remaining stands are referred to as relict outliers. The dominant species occurring in the area vary, depending on slope exposure, from Pinus ponderosa and Juniperus deppeana on the south-facing slopes to …
The Effect Of Cesium-123 On Cesium-137 Uptake By Tissues In The Laboratory Rat, Richard Riley Tokarz
The Effect Of Cesium-123 On Cesium-137 Uptake By Tissues In The Laboratory Rat, Richard Riley Tokarz
Biology ETDs
The effects of stable cesium-133 on cesium-137 metabolism were studied to better define mechanisms of cesium transport and binding by rat tissues. The extent to which the hypothetical cesium transport system can be overloaded was examined by giving cesium-133 and cesium-137 intraperitoneal injections within short time intervals. Whole animal and isolated tissue counts were made with a small animal whole body counter. Stable cesium-133 (0.02 g per animal) injected from 3 minutes to 24 hours prior to cesium-137 (0.15 ml containing 0.24 µCi per 100 g body weight) had little effect on the uptake of cesium-137 by tissues. Expressing data …
A Comparative Food Habit Study Of Two Species Of Kangaroo Rats - Dipodomys Ordi And Dipodomys Merriami, Marilyn Kobylack Dunham
A Comparative Food Habit Study Of Two Species Of Kangaroo Rats - Dipodomys Ordi And Dipodomys Merriami, Marilyn Kobylack Dunham
Biology ETDs
The present study was undertaken to investigate the food habits in two species of kangaroo rats, Dipodomys ordi Woodhouse and Dipodomys merriami Mearns, by comparing the seeds that they store in their cheek pouches. Since both species of kangaroo rat occur sympatrically at many places in the Southwest, Gennaro (1966) has concluded that interspecific competition with D. ordi might serve to limit the northern distribution of D. merriami in the Rio Grande Valley of New Mexico. The nature of this interspecific relationship was investigated through a comparison of the seeds of both species.
Investigations have revealed that there is a …
Studies Of Diet As A Factor In 137-Cesium Metabolism In Rats, Morris Burton Snipes
Studies Of Diet As A Factor In 137-Cesium Metabolism In Rats, Morris Burton Snipes
Biology ETDs
Effects of diet on 137Cs retention and distribution in the rat were examined. After a 7-day period, retention of an intraperitoneal dose of 137Cs was higher than control values for rats fed semistarvation, high carbohydrate, high protein, and high fat diets. Relative distribution of 137Cs among tissues .was examined considering changes in tissue composition due to diet variation. The primary effect of diet on cesium metabolism was a modification of cesium excretion via urine and feces. There appeared to be a direct relationship between mass of fecal material and the amount of 137Cs excreted in feces. …
Geographical Variation Of The Apache Pocket Mouse In New Mexico, Daniel F. Williams
Geographical Variation Of The Apache Pocket Mouse In New Mexico, Daniel F. Williams
Biology ETDs
The geographic variation of Perognathus apache Merriam in New Mexico was investigated to determine the relationship of P. apache to P. flavescens Merriam and the relationships of the subspecies of P. apache to each other. Skin and skull measurements of adult specimens were analyzed statistically. Relative color values for adult specimens were estimated by selecting two individuals as color standards and comparing the other specimens with the standards. Apache pocket mice from southwestern New Mexico were found to be closer in size and proportions to the smaller P. flavescens from eastern New Mexico than to the larger Apache pocket mice …
Behavioral Changes In Ants During Radiation Exposure, Niel Henry Milton Berg
Behavioral Changes In Ants During Radiation Exposure, Niel Henry Milton Berg
Biology ETDs
There are only a few reports concerning the response of ants to irradiation and the majority of these are based on unpublished work. Apparent misinterpretations regarding the avoidance by ants of irradiation have occurred because of confusion as to dose, dose rate, and the type of radiation used. The only apparent demonstration of ant avoidance to radiation was made using x-rays at dose rates of 50-70 r/sec, although one author cites evidence for an ant avoidance response to 10 r/hr of 137Cs gamma rays.
In the present study, queen ants of the genus Pogonomyrmex, and worker ants of the species …
Cultivation Of Trypanosoma Peromysci From Two Species Of Peromyscus, Norman R. Dollahon
Cultivation Of Trypanosoma Peromysci From Two Species Of Peromyscus, Norman R. Dollahon
Biology ETDs
Trypanosomes from mice of the species Peromyscus boylii and Peromyscus truei were isolated and cultured in NNN medium and in trypticase soy medium. A continuing culture of trypanosomes developed from blood of mice of the species P. truei. Trypanosomes from the blood of mice of the species P. boylii did not adapt to continuing cultures, but crithidias and rosettes were observed.
The cultures were incubated at temperatures of 1.5 C, 22 C, and 37 C. The organisms incubated at 1.5 C never advanced beyond the crithidial form, but they were observed in the culture medium after 40 days. The organisms …
The Soluble Antigens Of Pasturella Pestis, Loris William Hughes
The Soluble Antigens Of Pasturella Pestis, Loris William Hughes
Biology ETDs
The soluble antigens of a virulent, newly isolated strain of Pasteurella pestis were compared to the antigens of an avirulent, well-documented strain (A-1122). The virulent strain gave two immunogenic fractions when passed through a Sephadex G-200, superfine column. The avirulent strain gave four. All fractions from both strains had a common antigen. The method of Sephadex separation appeared to be an excellent means for the separation and purification of the soluble antigens of P. pestis.
The Specific Suppression Of The Primary Immune Response By Passive Administration Of Mouse Antibody Fractions, Catherine Spain Safford
The Specific Suppression Of The Primary Immune Response By Passive Administration Of Mouse Antibody Fractions, Catherine Spain Safford
Biology ETDs
The primary immune response can be specifically suppressed by the passive administration of the homologous antibody close to the time of the primary antigenic stimulus. Although the mechanism of this antibody-mediated suppression of the immune response has not yet been elucidated, it is known that both ϒM ( (19S) and ϒG (7S) antibodies can function as inhibitors, ϒG antibodies being approximately 100 to 200 times more effective than ϒM antibodies. In mice and in several other animals the ϒG antibody has been further separated into two subclasses, designated 7Sϒ1 and 7Sϒ2 globulins. These two classes are distinguished by …
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 …
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.
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 …
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 …
Aspects Of The Life History And Distribution Of The Jemez Mountains Salamander, Plethodon Neomexicanus, Douglas P. Reagan
Aspects Of The Life History And Distribution Of The Jemez Mountains Salamander, Plethodon Neomexicanus, Douglas P. Reagan
Biology ETDs
Plethodon neomexicanus, the Jemez Mountains Salamander, is endemic to the Jemez Mountains where it is restricted to talus slopes that are forested and shaded and that have suitable conditions of moisture and temperature. During the summer of 1966 four new localities were found, yielding information on the combination of factors which favor the presence of this salamander. Its habitat is at elevations of 7900-9200 ft within the upper montane forest of the Rocky Mountains. In the Jemez Mountains this forest exists at these elevations only on shaded north-facing slopes or in deep, shaded canyons. The presence of volcanic talus provides …
Studies Of Sodium-22 Distribution During Hypothermia In Rattus Rattus, David N. Danforth Jr.
Studies Of Sodium-22 Distribution During Hypothermia In Rattus Rattus, David N. Danforth Jr.
Biology ETDs
The response of regional circulation to reduced body temperature was studied in the white laboratory rat Rattus rattus, using injected 22Na as a tracer. Observations made on equilibration of plasma and tissue radiosodium, in normo- and hypothermic animals, provided evidence as to possible mechanisms responsible for transport of sodium at this interface. Evidence is also presented as to disposition of sodium in tissues during the first biological half-life.
Circulation to the peritoneal cavity is reduced to 50%, and to skin and bone approximately 10% and 25% of normothermic values respectively at body temperatures of 16-18 C. The appearance of …
Trypanosomes Found In Four Species Of Peromyscus, Alonzo J. Drummond Jr.
Trypanosomes Found In Four Species Of Peromyscus, Alonzo J. Drummond Jr.
Biology ETDs
Blood of 311 mice belonging to the genus Peromyscus was examined for the presence of trypanosomes. All four species, P. boylii, P. truei, P. leucopus, and P. maniculatus, were found to be infected with the hemoflagellate Trypanosoma peromysci. Mice of the species P. boylii and P. truei were found to have the highest percentage infection, 28.1% and 25.9%, respectively. The other two species, P. leucopus and P. maniculatus, demonstrated lower infection percentages, 7.9% and 11.4%, respectively.
Mice of the subadult and young adult age group were found to have a higher percentage of infection than did mice of the juvenile …