Showing papers by "University of Saskatchewan published in 1972"
TL;DR: Through modifications of the original methods used in the DNA hybridization work, techniques have been developed which make each chromosome identifiable and these observations were later made on human chromosomes.
Abstract: THE differential staining properties of the Giemsa stain were first observed by Pardue and Gall1. They were studying in situ hybridization between mouse satellite DNA and mouse chromosomes and observed that following certain pretreatment the centromeric regions of mouse chromosomes were more densely stained by Giemsa stain than other regions. The darkly stained regions were considered to consist of constitutive heterochromatin. Similar observations were later made on human chromosomes by Arrighi and Hsu2 and Gagne et al.3. Through modifications of the original methods used in the DNA hybridization work, techniques have been developed which make each chromosome identifiable4–6.
500 citations
TL;DR: The crystal structure of FeVO4 has been determined in this article, where three independent iron atoms (two in distorted octahedral and one in a distorted trigonal bipyramidal environment) are joined to create a doubly bent chain of six edge-sharing polyhedra.
121 citations
TL;DR: Richardson's ground squirrels, Spermophilus richardsonii, are territorial in Saskatchewan and young males had a greater tendency to disperse than any other age and sex, a tendency which would promote outbreeding in a population where related females maintain the same territory from year to year.
Abstract: Richardson's ground squirrels, Spermophilus richardsonii , are territorial in Saskatchewan. Males defend territories prior to, and during, the mating period only. Female territorial behavior is apparent from 1 week after emergence until hibernation. Female territories are retained from year to year by one individual or are transmitted from a female of one generation to a related female of the next. This behavior may promote a decrease in agonistic encounters in the spring inasmuch as fewer interactions would be needed to re-establish territorial boundaries. Recognition results in a reduction of fighting between relatives and also may be important in the initial learning of territorial boundaries by the young.
There was a differential utilization of habitat resulting in adult males being active from mid-March to early June, adult females from early April to mid-July, and some young ground squirrels from mid-May until October. The early disappearance of adults could be one means of limiting exploitation of resources and increasing survival of the young.
Peaks of agonistic behavior are correlated with the establishment of territories in the spring and with increases in the home range movements of young residents in midsummer. The peak in cohesive behavior is correlated with the emergence of young and results primarily from play with, and recognition of related individuals.
Young males had a greater tendency to disperse than any other age and sex, a tendency which would promote outbreeding in a population where related females maintain the same territory from year to year.
80 citations
TL;DR: The administration of pyridoxine together with the INH prevented the onset of seizures and lessened the effect of the InH on GABA levels and GAD activity but not on GABA‐T activity, suggesting the possibility that a deranged GABA metabolism is responsible for hydrazide‐induced seizures.
Abstract: —The effect of intramuscularly administered INH on brain levels of GABA in chicks was dependent on the amount injected. A subconvulsant dose of INH (1·1 mmol/kg) produced a slow steady decline in the level of GABA, whereas a convulsant dose (2·19 mmol/kg) brought about a sequential fall and rise in GABA level. This sequence of events reflected changes in the relative activities of GAD and GABA-T brought about by the hydrazide. The administration of pyridoxine together with the INH (2·19 mmol/kg) prevented the onset of seizures and lessened the effect of the INH on GABA levels and GAD activity but not on GABA-T activity. The possibility that a deranged GABA metabolism is responsible for hydrazide-induced seizures is discussed.
75 citations
TL;DR: When soybean cells were grown in medium with NO3- plus NH4+, dry weight and NR activity remained relatively low for several hours after which both increased rapidly, coincided with the time NH4+ was depleted from the medium.
Abstract: Soybean (Glycine max L. cv. Mandarin) and wheat (Triticum monococcum L.) cells were grown in media with NO3- plus NH4+ (B5) and NO3- without NH4+ (B5-NH4) as nitrogen sources. Changes in pH, [NO3-] and [NH4+] in media, and dry weight, protein content, nitrate reductase (NR) and glutamate dehydrogenase (GDH) in the cells were followed for about 170 h. With both NH4+ and NO3- in the medium, NH4+ was utilized very quickly. Soybean cells grew poorly in the absence of NH4+ while wheat cells grew equally well on media with or without NH4+. When soybean cells were grown in medium with NO3- plus NH4+, dry weight and NR activity remained relatively low for several hours after which both increased rapidly. This coincided with the time NH4+ was depleted from the medium. In the absence of NH4+, soybean cell growth and NR activity remained low. NR activity in wheat cells, and GDH activity in soybean and wheat cells, did not vary significantly in the presence or absence of NH4+.
72 citations
TL;DR: The intramuscular administration of INH to chicks caused striking changes in brain GABA metabolism during a 16 h period following the injection and seizure activity in the chicks did bear a relationship to a function which incorporated changes in both GABA levels and GAD activity.
63 citations
TL;DR: Acetylcholinesterase activity in cultures of dissociated skeletal muscle prepared from the thigh muscle of the 10-day-old chick embryo was increased by the presence of innervating spinal cord explants, spinal cordExplants in a parabiotic environment, and by media containing brain-spinal cord extract.
Abstract: Acetylcholinesterase activity in cultures of dissociated skeletal muscle prepared from the thigh muscle of the 10-day-old chick embryo was increased by the presence of innervating spinal cord explants, spinal cord explants in a parabiotic environment, and by media containing brain-spinal cord extract.
58 citations
TL;DR: In this paper, the doubly excited quartet levels in Be II and the displaced term system of Be I were investigated and a term scheme for these quartets was proposed, and a number of the observed lines were also identified with the Be I 2pnl1L, 3L system.
Abstract: An investigation of the doubly-excited quartet levels in Be II and the displaced term system of Be I is described. Beam-foil spectra of beryllium (500-1 600 A, 2 000-6 000 A) showed several transitions which were assigned to doubly-excited Be II. A term scheme for these quartet levels is proposed. A number of the observed lines were also identified with the Be I 2pnl1L, 3L system. Radiative lifetimes have been determined for several excited levels in Be I and Be II.
57 citations
TL;DR: In this paper, it was shown that any crystallographic Coxeter group appears as the Weyl group of some Tits' system (or (B, N)-pair) [I 1 by 1].
53 citations
52 citations
TL;DR: A total of 216 raw milk samples with a variety of Standard Plate Counts and psychrotrophic bacteria counts were laboratory-pasteurized, stored at 7 C, and then evaluated for flavor after 1 and 2 weeks.
Abstract: A total of 216 raw milk samples with a variety of Standard Plate Counts and psychrotrophic bacteria counts were laboratory-pasteurized, stored at 7 C, and then evaluated for flavor after 1 and 2 weeks. Results showed that milk with counts of >1,000,000/ml before heating frequently developed objectionable flavors after pasteurization and subsequent storage. The most common defect was a bitter flavor which appeared within 2 weeks after pasteurization in nearly all samples which as raw milk had counts exceeding 10,000,000/ml. This off-flavor developed in spite of small numbers of organisms in the pasteurized product and in the absence of post-pasteurization contamination.
TL;DR: It is suggested that patients with pure extrapyramidal system involvement characterized by rigidity, akinesia and bulbar symptoms and who fail to improve on levodopa should have a pneumoencephalogram, if this shows dilatation of the lateral ventricles and possibly atrophy of the head of the caudate nucleus the diagnosis of striatonigral degeneration should be strongly suspected.
TL;DR: The close correlation between morphological development of myelin and synapses, and the increased activity levels of the enzymes, acetylcholinesterase and pseudocholinestersterase, is proved in the present study.
TL;DR: In this article, high-frequency (ω ωci) electrostatic instabilities driven by an electron-ion relative drift velocity across an external magnetic field are discussed for an inhomogeneous plasma.
Abstract: High-frequency (ω ωci) electrostatic instabilities driven by an electron-ion relative drift velocity across an external magnetic field are discussed for an inhomogeneous plasma. The presence of a density gradient perpendicular to the magnetic field has been found to greatly reduce critical velocities for the onset of several instabilities such as lower hybrid oscillations and ion cyclotron harmonic waves. It has been also shown that the lower hybrid instability can be caused by some positive dissipation mechanism such as Landau damping due to thermal ions and a finite electron collision rate. Some applications have been made to turbulent heating experiments in plasmas in which cross-field currents are present.
TL;DR: Evidence from light- and dark-grown peas does not support the concepts that differences in ABA are associated with differences in height or that ABA is a correlative inhibitor of stem elongation.
Abstract: Wilting tall or dwarf peas produced a marked increase in abscisic acid (ABA). Evidence from light- and dark-grown peas does not support the concepts that differences in ABA are associated with differences in height or that ABA is a correlative inhibitor of stem elongation.
TL;DR: The application of probability methods to the determination of generating capacity spinning reserve requirements has been illustrated in several publications and the basic difference between a static capacity reserve study and a spinning reserve study is in the time period considered.
Abstract: The application of probability methods to the determination of generating capacity spinning reserve requirements has been illustrated in several publications (1,2,3). The basic difference between a static capacity reserve study and a spinning reserve study is in the time period considered. The basic statistics in the first case are the probabilities of finding the existing and proposed units in various states at some time in the relatively distant future. In the spinning reserve case, the probabilities of having load carrying capability within the next few hours are required given that the system resides in a particular state at time zero. In each case, the actual system load is a variable and can be described by a probability distribution.
TL;DR: Under non-selective conditions, the mitochondrial marker derived from the haploid parent of a mating type predominated in zygote-daughter-cells; this asymmetrical distribution could be reversed by selective pressure for the marker transmitted with low frequency.
Abstract: Genetic analyses of 48-hr-old zygote-daughter-colony cells from crosses between chloramphenicol and erythromycin resistance markers located in mitochondrial DNA demonstrated homoplasmons of parental and recombinant genotypes, and heteroplasmons with recombinant and/or parental genotypes. Although the heteroplasmons were unstable and the homoplasmic components could be segregated by plating on selective media, the heteroplasmic state was often maintained beyond 19 cell divisions when grown on non-selective medium. Homoplasmons of recombinant genotype from repulsion crosses were observed with a frequency of 7.2, 9.0, 11.2 and 11.4 percent; two crosses with the resistance markers in coupling had 5.4 and 11.5 percent recombinants. Under non-selective conditions, the mitochondrial marker derived from the haploid parent of a mating type predominated in zygote-daughter-cells; this asymmetrical distribution could be reversed by selective pressure for the marker transmitted with low frequency. The challenge with chloramphenicol and erythromycin of zygotes from crosses of resistance-markers in repulsion revealed that inter-mitochondrial complementation was not occurring.
TL;DR: In this article, various nitrogen compounds were tested for their ability to alleviate the reduced nitrogen requirement of soybean cells growing in defined liquid medium containing nitrate as the alternative nitrogen source.
Abstract: Various nitrogen compounds were tested for their ability to alleviate the reduced nitrogen requirement of soybean cells growing in defined liquid medium containing nitrate as the alternative nitrogen source. Either l-glutamine, l-alanine, putrescine or NH4
+ satisfied this requirement. Addition of l-glutamate resulted in poor growth. Where growth was stimulated, nitrate reductase (NR) activity increased whereas glutamate dehydrogenase activity in the cells showed no such correlation. In all fresh media which supported rapid growth, NR activity first decreased rapidly to a low value. Subsequent dry weight increases occurred concommitantly with an increase in NR activity. When 2,4-dichlorophenoxyacetic acid was omitted from the medium the growth was slow and the NR activity did not increase. During the first 40 h of incubation in medium containing NH4
+ plus NO3
- the cells produced a growth-enhancing factor(s). This factor(s) was present in the cells and in the medium and eliminated the requirement for reduced nitrogen.
TL;DR: It is proposed that the symmetry of contraction is due to a rapid sequestering of Ca++ by the SR collars at the middle of the A-bands and a possible diffusion barrier at that level.
Abstract: The ascidian myocardium is composed of small striated myoepithelial cells. The sarcoplasmic reticulum (SR) of these cells was reconstructed from serial sections. T-tubules are absent, but subsarcolemmal cisternae of the SR, that may be the counterpart of terminal cisternae, form couplings with the sarcolemma. Longitudinal SR tubules, parallel to the myofilaments, are interconnected near the middle of the A-band and form a transverse collar. Cinematographic photography of spontaneous contractions in fresh myocardial preparations produced records that could be analyzed frame by frame. Contractions are typically limited to parts of the myofilament field of single cells. They are locally symmetrical with respect to Z-bands; either both A-bands on each side of a Z-band converge on it (contractions), or neither A-band moves with respect to the Z-band. It is suggested that the spontaneous contractions are the result of local Ca++ release from randomly distributed subsarcolemmal cisternae. It is proposed that the symmetry of contraction is due to a rapid sequestering of Ca++ by the SR collars at the middle of the A-bands and a possible diffusion barrier at that level.
TL;DR: In this article, the authors compared DE sunflower meal and protein isolate with untreated samples for their nitrogen extractability and moisture adsorption and found that DE meal prepared at 80°C had low solubility over a pH range of 1-11 which indicated substantial denaturation of the sunflower proteins.
Abstract: Diffusion-extracted (DE) sunflower meal and protein isolate were compared with untreated samples for their nitrogen extractability and moisture adsorption. Nitrogen extractability values of 90% were found at pH 7 or above in the untreated meal, whereas a maximum solubility of only 70% was achieved at pH 9.0 in the DE meal prepared at 60°C. DE meal prepared at 80°C had low solubility over a pH range of 1–11 which indicated substantial denaturation of the sunflower proteins. The untreated isolate showed a sharp minimum solubility point in contrast to the law solubility of the DE isolate over a pH range of 3–7. Moisture adsorption values for the samples held at 5, 20 and 30°C indicated little difference in moisture contents at relative humidities of 11–55%. At higher levels, however, the untreated meal adsorbed more moisture than the DE meal. A reverse trend was noticed for the isolates as the moisture content of the DE isolate was higher than the untreated sample. The rate of moisture uptake by sunflower kernels was slower than that observed with rapeseed or soybean meats and lower total moisture contents were observed after a 4 hr soaking period.
TL;DR: In this paper, a process for the diffusion extraction of glucosinolates from rapeseed was described, based on the principle that low molecular weight glucosins will passively diffuse through seed membranes which retain proteins and triglycerides.
Abstract: A process is described for the diffusion extraction of glucosinolates from rapeseed. The detoxification procedure is based on the principle that low molecular weight glucosinolates will passively diffuse through seed membranes which retain large molecules such as proteins and triglycerides. The diffusion rates of glucosinolates, sugars, polyphenols and some N compounds were affected by extraction time and temperature, agitation, seed to solvent ratio and pH of the aqueous medium. Five or six 1-h extractions with 0.01N NaOH at 60°C were sufficient to remove all but traces of the glucosinolates present in turnip rape and rape. Boiling of the seed before aqueous extraction was necessary to control the myrosinase activity and maintain the sulfur content of the oil at less than 10 ppm. The diffusion extracted rapeseed contained a higher proportion of oil and crude fiber but lower percentages of crude protein, ash and N-free extract than control samples. The detoxified rapeseed could be used directly in feeds and foods or further processed into a meal, flour, protein concentrate or isolate.
TL;DR: In this article, an open econometric model is developed to estimate the simultaneous relationships prevailing among the demand, supply and price, and export variables within the Canadian beef cattle sector.
Abstract: Limited information is available concerning the relationships existing among demand, supply, and price within the Canadian beef cattle sector. Since the sector is very dependent on exports to the U.S.A., an open econometric model is developed to estimate the simultaneous relationships prevailing among the demand, supply and price, and export variables. The two‐stage least squares procedure is adopted to obtain a solution. It was estimated that by 1975 both Canadian domestic demand for beef and farm prices of beef will increase, but exports of live cattle will decline. The model also revealed that the price and production levels of feed grains are important factors in accommodating the expansion of demand.
TL;DR: The regular excretion of mandelic acid in Phenylketonuria is confirmed in this study and its excretion in eight cases of uncontrolled phenylket onuria is reported.
TL;DR: Cholestyramine (12 g/day) was administered to four subjects with familial hyperchloesterolemia (type II) for 12 to 15 days and no evidence of degradation of the steroid nucleus was detected during its passage through the gastrointestinal tract.
Abstract: Cholestyramine (12 g/day) was administered to four subjects with familial hyperchloesterolemia (type II) for 12 to 15 days. Plasma cholesterol values fell by 24 to 28% in all subjects. Total endogenous fecal steroids increased from 2.0 to 2.5 times over the control values. This increment was mainly in the acidic fraction which increased from 1.4 to 6.5 times during treatment. The neutral steroid fraction showed a slight increase (nonsignificant) in two subjects and a significant increase (P < 0.05) in one subject. The total fecal steroid increment was considerably in excess of the decrement in plasma cholesterol, thus indicating either (a) a substantial increase in cholesterol synthesis, (b) a transfer of cholesterol from depots, or (c) both. Plasma cholesterol specific activity time curves showed a sharp increase in the slope immediately after the commencement of treatment, reflecting an increase in the rate of entry of unlabeled cholesterol into the readily miscible pool. Since cholestyramine did not ch...
TL;DR: It was concluded that propionate is first transported by the acetate transport system then metabolized via conversion to acetate by oxidation through pyruvate and also via the hydroxyglutarate pathway.
TL;DR: Energy requirements of captive Lesser Scaup ducks (Aythya affinis) were determined from hatching to 12 weeks using a feeding trial and comparative slaughter method and a similar trend occurred in wild scaup though percentages were lower due to the lower fat content.
TL;DR: In this article, the usual spherical island model is extended to the cases of oblate spheroid and disc shaped islands, and the effects of island-substrate contact angle variation are attributed to uncertainty in the determination of structural parameters.