Open Access. Powered by Scholars. Published by Universities.®

Biology Commons™

Open Access. Powered by Scholars. Published by Universities.®

Metabolism

Discipline
Institution
Publication Year
Publication
Publication Type
File Type

Articles 181 - 190 of 190

Full-Text Articles in Biology

The Effects Of Temperature And Rain On The Metabolism Of The American Kestrel (Falco Sparverius), Glenn R. Wilson May 1996

The Effects Of Temperature And Rain On The Metabolism Of The American Kestrel (Falco Sparverius), Glenn R. Wilson

Biology

The change in metabolism of birds exposed to rainfall is poorly understood. I measured the rate of oxygen consumption (VO2) using open-flow respirometry of four male and four female American kestrels (Falco sparverius) during the breeding season at ambient temperatures (Ta) of 5, 10, 15, and 25°C in air without rainfall and then at low (2.5 cm⋅h-1) rainfall and high (6.1 cm⋅h-1) rainfall. Trial order was analyzed as a covariate because kestrel responses appeared to decrease in intensity during the 14-wk study period. The VO2 increased 12.65% at low …

Go to article

Radiation-Induced Fibrosis: The Structure/Function Relationship, J. C. Murray Feb 1994

Radiation-Induced Fibrosis: The Structure/Function Relationship, J. C. Murray

Scanning Microscopy

Fibrosis is a frequent complication of therapeutic radiation delivered to organ sites such as the thorax and pelvic region. We investigated the relationship between function, and biochemical and structural changes in the lung and colon of CBA mice irradiated with 240 kV X-rays. Progressive changes in lung function, as evidenced by increased breathing rates were observed out to 6 months post-irradiation. Biochemical studies demonstrated increased metabolism (synthesis and breakdown) of collagen around 6 months after irradiation, but provided no evidence of net collagen accumulation. Analysis of collagen isotypes revealed a slight increase in the ratio of types I and Ill. …

Go to article

Characteristics Of The Motor Responsible For The Gliding Of Native Microtubules From Squid Axoplasm, Dieter G. Weiss, Dieter Seitz-Tutter, George M. Langford Jan 1991

Characteristics Of The Motor Responsible For The Gliding Of Native Microtubules From Squid Axoplasm, Dieter G. Weiss, Dieter Seitz-Tutter, George M. Langford

Biology - All Scholarship

Nucleotide-dependent movement of native microtubules (nMTs) in squid axoplasm has biochemical and biophysical characteristics of kinesin-driven motility. However, the high vanadate and N-ethylmaleimide sensitivity and the velocity demonstrate that the properties of the native motile system differ considerably from those of purified kinesin preparations.

Go to article

Atp-Dependent Formation And Motility Of Aster-Like Structures With Isolated Calf Brain Microtubule Proteins., Richard C. Weisenberg, Robert D. Allen, Shinya Inoue Mar 1986

Atp-Dependent Formation And Motility Of Aster-Like Structures With Isolated Calf Brain Microtubule Proteins., Richard C. Weisenberg, Robert D. Allen, Shinya Inoue

Dartmouth Scholarship

Microtubule proteins isolated from calf brain will undergo gelation-contraction in the presence of ATP. We have now examined this process by video-enhanced contrast microscopy. After ATP addition to steady-state microtubules, slow (1-5 micron/min), linear movements of particles and microtubules toward aggregation centers occur. The resulting structures resemble mitotic spindle asters. During the time when gel contraction occurs, asters move (at 1-5 micron/min) toward other nearby asters. This is accompanied by the apparent shortening of the microtubules running between the asters. This is the first example of isolated microtubules undergoing a process that has similarities to half-spindle shortening during anaphase A. …

Go to article

Isolation Of A Collagenase Cdna Clone And Measurement Of Changing Collagenase Mrna Levels During Induction In Rabbit Synovial Fibroblasts., Robert H. Gross, Lynn A. Sheldon, Colin F. Fletcher, Constance E. Brinckerhoff Apr 1984

Isolation Of A Collagenase Cdna Clone And Measurement Of Changing Collagenase Mrna Levels During Induction In Rabbit Synovial Fibroblasts., Robert H. Gross, Lynn A. Sheldon, Colin F. Fletcher, Constance E. Brinckerhoff

Dartmouth Scholarship

To facilitate our studies on the mechanisms controlling collagenase production at a molecular level in rabbit synovial fibroblasts, we have constructed a cDNA library using mRNAs isolated from cells induced with crystals of monosodium urate monohydrate. We have screened this library with cDNA probes made from induced and control mRNA populations. From among 30 clones that hybridized preferentially to the induced-cell probe, 4 contained collagenase sequences. The largest, a clone of 650 base pairs, was identified by its ability to hybrid select a mRNA that could be translated in a cell-free system into a product that was precipitable with monospecific …

Go to article

The Effects Of Osmotic Stress On Sodium, Potassium, And Chloride Metabolism In The Mongolian Gerbil, Meriones Unguiculatus, Mark William Hagood May 1982

The Effects Of Osmotic Stress On Sodium, Potassium, And Chloride Metabolism In The Mongolian Gerbil, Meriones Unguiculatus, Mark William Hagood

Master's Theses

The effects of osmotic stress on sodium, potassium, and chloride metabolism and the physiological mechanisms governing these ions were studied in the Mongolian gerbil, Meriones unguiculatus. Animals were subjected to dietary regimens ranging from sodium-free to high-sodium diets for sixty days. Results indicate the gerbils were not physiologically stressed by the imposed diets. Apparently the animals regulate ion metabolism via intrarenal mechanisms and pituitary antidiuretic hormone while behavior and adrenal cortical activity are insignificant.

Go to article

Synthesis Of Low Molecular Weight Heat Shock Peptides Stimulated By Ecdysterone In A Cultured Drosophila Cell Line., Robert C. Ireland, Edward M. Berger Feb 1982

Synthesis Of Low Molecular Weight Heat Shock Peptides Stimulated By Ecdysterone In A Cultured Drosophila Cell Line., Robert C. Ireland, Edward M. Berger

Dartmouth Scholarship

Treatment of Schneider's line 3 Drosophila cells with the steroid hormone ecdysterone rapidly stimulated the synthesis and accumulation of the polypeptide previously designated p7 [Berger, E. M., Ireland, R. C. & Wyss, C. (1980) Somatic Cell Genet. 6, 119-129]. In this report, p7 is identified as the 23,000-dalton heat shock polypeptide (hsp23). In addition to hsp23, the synthesis of the low molecular weight heat shock polypeptides hsp22, hsp26, and hsp27 was also stimulated by ecdysterone, although to different extents. Hybridization of a nick-translated genomic clone containing the hsp23 gene to a total RNA blot showed that ecdysterone stimulation of hsp23 …

Go to article

Biphenyl Hydroxylation By Vole Hepatic Microsomes, Moheb H. Makary May 1981

Biphenyl Hydroxylation By Vole Hepatic Microsomes, Moheb H. Makary

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Metabolism of biphenyl by meadow voles (Microtus montanus) liver microsomes was studied by gas liquid chromatography. The microsomal biphenyl hydroxylation of Swiss Webster mice (outbred) was also investigated to provide a species comparison. 4-hydroxybiphenyl (major metabolite), 3-hydroxy biphenyl (minor) and smaller amounts of 2-hydroxybiphenyl were identified as metabolites of biphenyl incubated with vole liver microsomes. Liver microsomes from Swiss mice formed 4-hydroxy biphenyl (major metabolite) and almost equal amounts of 2- and 3-hydroxy biphenyl (minor metabolite). The amount of the hydroxy biphenyls formed by vole liver microsomes was considerably less per milligram of microsomal protein than for mice. …

Go to article

The Metabolic Cost Of Behavioral Thermoregulation Of Body Temperature In The Northern Alligator Lizard Gerrhonotus Coeruleus, And How It Affects The Classical Concept Of Eurythermality, James Dudley Campbell Jan 1981

The Metabolic Cost Of Behavioral Thermoregulation Of Body Temperature In The Northern Alligator Lizard Gerrhonotus Coeruleus, And How It Affects The Classical Concept Of Eurythermality, James Dudley Campbell

Dissertations and Theses

The effect of total metabolic cost expenditures on the precision of behavioral thermoregulation was investigated for the purportedly eurythermic Northern Alligator lizard (Gerrhonotus coeruleus). An operant apparatus was designed to test metabolic output at different heat reinforcement magnitudes. The mean TB reflected in each trial was positively correlated to the length of reinforcement. The shuttle rate during each trial was inversely correlated to the length of reinforcement. The standard deviation and total metabolic costs did not vary significantly between trials undertaken at the same ambient temperature. Eurythermality in G. coeruleus is caused by fluctuations in preferred body temperature and …

Go to article

Arrangement Of Subunits In Microtubules With 14 Profilaments, George M. Langford Nov 1980

Arrangement Of Subunits In Microtubules With 14 Profilaments, George M. Langford

Biology - All Scholarship

The structure of 14-protofilament microtubules reassembled from dogfish shark brain tubulin was analyzed by high resolution electron microscopy and optical diffraction. The simultaneous imaging of the protofilaments from near and far sides of these tubules produces a moiré pattern with a period of approximately 96 nm. Optical diffraction patterns show that the 5-nm spots that arise from the protofilaments for the two sides of the tubule are not coincident but lie off the equator by a distance of 1/192 nm-1. These data provide evidence that in reassembled microtubules containing 14 protofilaments, the protofilaments are tilted 1.5 degrees with respect to …

Go to article

First Prev