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Full-Text Articles in Life Sciences
Community Characteristics Of Six Burned Aspen-Conifer Sites And Their Related Animal Use /|Clarry H. Kleinman, Larry H. Kleinman
Community Characteristics Of Six Burned Aspen-Conifer Sites And Their Related Animal Use /|Clarry H. Kleinman, Larry H. Kleinman
Theses and Dissertations
Six forest areas destroyed by fire representing different seral stages of aspen development and conifer invasion were studied to determine successional dynamics and the related livestock and big game use. Factors measured were: (a) age, basal area, density and frequency of aspen and conifer trees; (b) density and frequency of under-story species; (c) forage production for forbs, grasses, and browse, and (d) animal-days use for deer, cattle and sheep. Aspen appeared in the community the spring following the fire and conifers appeared fifteen to twenty years later. Conifers had begun to dominate aspen on an eighty-two year old stand. The …
Habitat And Time Utilization Of A Pair Of Nesting Sharp-Shinned Hawks (Accipiter Striatus Velox) : A Telemetry Study, Joseph Belnap Platt
Habitat And Time Utilization Of A Pair Of Nesting Sharp-Shinned Hawks (Accipiter Striatus Velox) : A Telemetry Study, Joseph Belnap Platt
Theses and Dissertations
Telemetric observations were conducted on a pair of Sharp-Shinned Hawks (Accipiter striatus velox) nesting in Spanish Fork Canyon, Utah in 1972. The movements of both adults were monitored from the time their eggs hatched in late June until they left the study area in early August, fourty-two days later. A transmitter was also attached to one of the young at the time of fledging. The adult's main hunting area was a single plant community located 1600 meters from the nest. The male performed the majority of the foraging while the female spent the greatest part of her time at the …
Speciation In The Genus Sceloporus Sceloporus (Sauria, Iguanidae) As Determined By Cranial Osteology And Other Characters, Kenneth Rex Larsen
Speciation In The Genus Sceloporus Sceloporus (Sauria, Iguanidae) As Determined By Cranial Osteology And Other Characters, Kenneth Rex Larsen
Theses and Dissertations
Numerical statistical methods were used to analyse the species in the genus Sceloporus using cranial osteology, external meristic and numeric characters, karyology, display behavior and geographic distribution. A new phylogeny for the genus is proposed with three main branches or Groups: Group I, a primitive group, evolved from Uta, Urosaurus and Sator in Miocene times. This Group speciated from gadoviae in the south to merriami in the north and contains 7 species in 3 species groups. Group II arose from Group I and evolved from centrally located pictus in all directions throughout Mexico. It contains approximately 19 species in 5 …
Growth And Development Of The Western Harvest Mouse, Reithrodontomys Megalotis Megalotis, Gary H. Richins
Growth And Development Of The Western Harvest Mouse, Reithrodontomys Megalotis Megalotis, Gary H. Richins
Theses and Dissertations
Growth rates, gestation period, litter size, reproductive age, sex ratios, and development were studied on 198 litters of Reithrodontomys megalotis megalotis. Growth was characterized by several standard skull and body measurements, and was partitioned into four phases of 1-3, 4-12, 13-22, and 23-70 days. Growth was best described by measurements of tail length, ear length, and dried eye lens weight. Reproductive activity began as early as 38 days for females and 59 days for males. Gestation period was 22 days and mean litter size was 3.83 (range 1-7). Sex ratio was 53.49% males to 46.51% females. Reproductive efficiency was 53.53%. …
Reproduction And Development Of Ferrissia Rivularis (Say) (Basommatophora: Ancylidae) And The Effects Of Maleic Hydrazide On Its Development And Fecundity, Yuan-Hsu Kang
Theses and Dissertations
Ferrissia rivularis was selected for research because of its local accessibility and because essentially nothing was known of its reproduction and development. Reproductive and developmental biology is first described herein from the natural environment. This is then compared with the effects created by experimental exposure to a selected herbicide, maleic hydrazide, which might be a potential threat to certain invertebrates in the natural environment.
The Effects Of Thiamin Deficiency And Thiamin Antagonists On Cardiac Function In The Rat, D. James B. Sutherland
The Effects Of Thiamin Deficiency And Thiamin Antagonists On Cardiac Function In The Rat, D. James B. Sutherland
Theses and Dissertations
A study was made to determine what biochemical changes were involved in the slowing of the rat heart rate during thiamin deprivation, pyrithiamin or oxythiamin treatment. The appearance of bradycardia during progressive thiamin deficiency was shown to be related to the reduction in myocardial enzymatic activity of pyruvate (PDH) and 2-ketoglutarate (2-KGDH) dehydrogenase, and not due to inanition alone since pair-fed control rats did not show bradycardia until the agonal stage. Bradycardia was not the result of reduced energy since CP, ATP, ADP, and AMP levels remained normal even though PDH and 2-KGDH activity dropped to 20% of normal by …