Showing papers by "Memorial University of Newfoundland published in 1974"
TL;DR: Differential scanning calorimetry has been applied to the study of some simple model biomembranes and the endothermic phase transitions which they exhibit when transforming from the gel to liquid crystal phase have been studied, showing that clusters of gel and liquid crystalline lipids can coexist within this temperature range.
409 citations
Journal Article•
206 citations
TL;DR: Cumene hydroperoxide is capable of supporting the aromatic hydroxylation of a variety of compounds in the presence of hepatic microsomes and it is suggested that the oxenoid species of cytochrome P-450 involved in microsomal aromatic hydoxylation is present in a form equivalent to the ferryl from.
169 citations
TL;DR: Findings have been extended to determine the effect of minor changes in the headgroup and glycerol ‘backbone’ region of a series of N-methylated PE’s and their diether analogues on transition temperatures and heats and the appearance of a pretransition.
166 citations
TL;DR: An electron transport system that catalyzes the oxidation of NADH by organic hydroperoxides has been discovered in rat liver microsomes as mentioned in this paper, and a Km value for NADH of less than 3 μ m was obtained.
98 citations
TL;DR: This chapter describes Leucocytozoon and discusses the prevalence, taxonomy, life cycles, ultrastructure, pathogenesis, and pathology of these avian blood parasites, together with treatment in terms of prevention and control, immunity and cultivation.
Abstract: Publisher Summary This chapter describes Leucocytozoon. It discusses the prevalence, taxonomy, life cycles, ultrastructure, pathogenesis, and pathology of these avian blood parasites, together with treatment in terms of prevention and control, immunity and cultivation. Progress has been made in the knowledge of these parasites, but there is uncertainty about some of the many “species” and difficulties concerning life cycles, the experimental study of which demands satisfactory methods of maintaining hosts and vectors. Genetics is unexplored and cytological observations are reported on only one species. Intriguing epizootiological problems requiring ecological investigations of avian and insect hosts in different parts of the world await attention. These parasites can be used as models for research pertaining to the biology of cells. Information should be, especially relevant to an understanding of the related coccidian and malaria parasites. Current interest in several places leads to the expectation of interesting discoveries during the next decade.
95 citations
TL;DR: It is suggested that higher valence states of cytochrome P-450 may function during the activation of oxygen for the hydroxylation of a variety of xenobiotics.
90 citations
TL;DR: Fractionation of isolated mitochondria by digitonin and by sonication revealed a matrix localization for phosphate-dependent glutaminase, a finding in agreement with its demonstrable latency.
70 citations
TL;DR: The results indicate that naphthalene oxygenase, 1,2-dihydroxynaphthalenes oxygenase and salicylaldehyde dehydrogenase are induced coordinately and it is suggested that all of the enzymes converting naphthaene to salicYLate are regulated coordinately.
63 citations
TL;DR: If rats drink equal quantities of two flavored solutions, but one flavored solution is consumed while thirsty and the other solution is eaten while nearly satiated, they will tend to prefer the thirst-correlated flavor when given a choice between the two solutions.
60 citations
TL;DR: In this article, a special method developed for harmonic analysis of non-equispaced data, applied to a 20-year record of observations with Loomis Polar Telescope of Yale University Observatory, sets an upper limit of 0"·12−0"·26 on the amplitude of any free nutation in obliquity in the frequency range 0−4 cpy.
Abstract: Summary
The existence of the Earth's liquid core, besides affecting the period of the Chandler wobble, gives rise to a second free wobble mode, with period short of a sidereal day by a factor of the order of the ellipticity of the coremantle boundary. Seen from space this nearly diurnal geographic motion of the pole should appear as a nutation of the Earth's rotation axis, with a period theoretically calculated to be about 460 days, and (as pointed out by Toomre) an amplitude correspondingly 460 times larger than that of the associated wobble. The curious history of the ‘nearly diurnal wobble’ problem is reviewed, and the relevant dynamics derived and described in terms of Poinsot's scheme. A special method developed for harmonic analysis of non-equispaced data, applied to a 20-year record of observations with Loomis Polar Telescope of Yale University Observatory, sets an upper limit of 0"·12–0"·26 on the amplitude of any free nutation in obliquity in the frequency range 0–4 cpy, i.e. an upper limit of 0"·0003–0"·0006 on the amplitude of the nearly diurnal free wobbble. This supports Toomre's contention that earlier reports of observations of this wobble, with amplitudes in the range 0"·01–0"·02, cannot be correct.
TL;DR: Rats were allowed to drink water while a stream of amyl acetate vapor was directed towards the end of the drinking spout and toxicosis was induced via the injection of lithium chloride after delays of 0.5, 1, 4, and 12 hr.
TL;DR: This article found that subjects were better at identifying both meaning and wording changes in concrete sentences and subjects took significantly longer to encode and decode the abstract sentences, and suggested that neither a dual-coding interpretation nor a semantic propositional coding model could adequately explain the results.
TL;DR: The results of Expts 2 and 3 suggest that the ability to form poison-based aversions to visual cues is not totally dependent upon a highly developed visual system.
TL;DR: The authors used an incidental learning paradigm to compare frequency judgments as a function of semantic versus non-semantic levels of processing, finding that frequency judgments are dependent on the level of processing activated by the presented words.
01 Jan 1974
TL;DR: The Appalachian orogen is a northeast-trending belt of deformed rocks that lies southeast of the Canadian Shield and Interior Platform of central North America (Fig 1) as mentioned in this paper.
Abstract: The Appalachian orogen is a northeast-trending belt of deformed rocks that lies southeast of the Canadian Shield and Interior Platform of central North America (Fig 1) The northernmost part of the orogen is bounded to the east by the Atlantic Ocean, and its southern part is overlain toward the east by Mesozoic sediments of the Atlantic coastal plain The mountain belt has an exposed area of 125,000 square miles in eastern Canada and extends from Newfoundland 2000 miles southwestward along the Atlantic seaboard to Alabama in the southeast United States The submerged offshore extensions of the orogen are covered by Mesozoic and Cenozoic sediments that form the Atlantic continental shelf Presumably, the Appalachian orogen was once continuous with the Caledonian Mountain System which consists of similar rocks with similar structural styles in Ireland and the United Kingdom on the eastern side of the North Atlantic
TL;DR: The application of the plate tectonic concept to the ancient past must therefore be determined by more indirect geological observations which are often open to more than one interpretation as discussed by the authors, but unfortunately much of the evidence is ephemeral.
Abstract: THE concept of plate tectonics explains the present behaviour of the Earth better than any rival hypothesis. Modern plate motion can be observed and measured, but unfortunately much of the evidence is ephemeral. Spreading ridges, trenches, oceanic magnetic lineaments, zones of seismic activity dipping under erogenic belts, and areas of anomalous heat flow are all destroyed or decay as the plate regime evolves. Applicability of the plate tectonic concept to the ancient past must therefore be determined by more indirect geological observations which are often open to more than one interpretation. For example, it can be inferred that melanges should develop in trenches associated with subduction1, but not all melanges originate in this way arid there is presently no easy way of typefying melanges. Thus, if the great variety of presently observed plate interactions existed in the past, geologic data may not be subtle enough to distinguish them and the record may be blurred beyond reasonable interpretation.
TL;DR: In this article, a well-preserved Chitinozoa was obtained from the uppermost part of the autochthonous sedimentary sequence of the Port au Port Peninsula in western Newfoundland, Canada.
TL;DR: Seasonal effects of nutrients and photoperiod on blade elongation were shown in long‐term laboratory experiments and Bidirectional flow of growth‐promoting metabolities within the stipe was demonstrated.
Abstract: SUMMARY
A seasonal rhythm in blade elongation rate was observed in Alaria esculenta. Maximum (3.0–3.6 cm/week) and minimum (0.5–1.0 cm/week) rates were recorded in June and September, respectively. Translocation of growth-promoting metabolites occurs within the main blade and between the sporophylls and blade. Bidirectional flow of growth-promoting metabolities within the stipe was demonstrated. Seasonal effects of nutrients (NO3- and PO43-) and photoperiod on blade elongation were shown in long-term laboratory experiments. Control of seasonal blade growth by exogenous and endogenous factors is discussed.
TL;DR: Though consumption of nonconditioned food was depressed during initial testing, the consumption of conditioned food was significantly less for six of eight test sessions, and an aversion to familiar food was initially weaker compared to novel food and extinguished more rapidly.
TL;DR: The results confirm the superiority of verbal memory processes in the retention of order information as discussed by the authors, which is independent of whether a verbal (Experiment I) or nonverbal response procedure was used.
Abstract: Ordered recall of 7-item sequences of sounds and words was compared in two experiments. Bow-shaped serial position curves were found for both types of sequences, but more errors occurred with sounds at all serial positions. This inferior recall of sounds was independent of whether a verbal (Experiment I) or nonverbal (Experiment II) response procedure was used. The results confirm the superiority of verbal memory processes in the retention of order information.
TL;DR: Cellulase (EC 3.2.1.4; beta-1, 4-glucan glucanohydrolase) was localized at the ultrastructural level and found to occur in dictyosomes and vesicles, around the periphery of unidentified storage bodies, and on the outer surface of the cell wall in the male strain of Achlya ambisexualis after treatment with the sex hormone antheridiol.
Abstract: Cellulase (EC 3.2.1.4; β-1, 4-glucan glucanohydrolase) was localized at the ultrastructural level and found to occur in dictyosomes and vesicles, around the periphery of unidentified storage bodies, between the plasmalemma and the cell wall, and on the outer surface of the cell wall in the male strain (E87) of Achlya ambisexualis after treatment with the sex hormone antheridiol.
TL;DR: A quantitative study of the littoral microcrustaceans in a bog pond and an acid marsh located on the Avalon Peninsula, Newfoundland, from May, 1972 to May, 1973 found that the dominant forms in the summer and fall were Cladocera and Copepoda.
Abstract: A quantitative study was made of the littoral microcrustaceans in a bog pond and an acid marsh located on the Avalon Peninsula, Newfoundland, from May, 1972 to May, 1973. A total of 17 species of Cladocera and 7 species of Copepoda were found in La Manche Marsh, while 21 species of Cladocera and 5 species of Copepoda were collected in Round Pond. The maximum standing stocks were similar in the two localities. The dominant forms in the summer and fall in La Manche Marsh were Cladocera: Acantholeberis curvirostris, Biapertura intermedia, Chydorus sphaericus, and Ilyocryptus spinifer. In the winter the copepod, Macrocyclops albidus, was dominant, while Cyclops varicans rubellus was the most abundant species in the spring. Round Pond also was dominated by Cladocera in the summer and fall; namely, Acroperus alonoides, Alona rustica, Alonella excisa, Chydorus sphaericus, and Sida crystallina. The copepods, Eucyclops agilis and Macrocyclops albidus, were dominant in the winter and early spring.
Journal Article•
TL;DR: In this paper, magnetic properties of three lava profiles (45 flows), basalt breccia and intrusives from the southernmost part of the west Greenland basalt area have been measured.
Abstract: Summary
Various magnetic properties of three lava profiles (45 flows), basalt breccia and intrusives from the southernmost part of the west Greenland basalt area have been measured. All samples contain a stable remanence component of reverse (R) polarity, in accord with most other rocks of the Brito-Arctic Lower Tertiary province. Three magnetic groupings were found: Class r. In the majority of lava samples, the NRM is dominated by the stable R component, which remains stable in direction under AF cleaning and has a characteristic single, high Curie point (Tc= 550–570 °C). Class n. One-quarter of the lava samples had a soft, normal NRM whose polarity switched to R under AF treatment at 50–100 Oe and became stable in higher fields. Class n samples often show both a low Tc (≤300 °C) and a high Tc, and their mean Koenigsberger ratio (0.43) is low compared to class r (2.9). Class r′ behaviour, combining r and n features, occurs especially in the breccia, intrusives and remaining lavas. Laboratory viscous build-up tests indicate that the soft component prominent in n and r′ rock is a VRM acquired during the present (Brunhes) geomagnetic epoch. Rock of different classes frequently co-exists even in single flows; this is attributed simultaneously to (1) spatial differences in oxygen fugacity during initial cooling, and (2) variations in titanomagnetite domain-size distribution near the singledomain-super-paramagnetic threshold. Spatial variations in the rate of lava extrusion and of cooling can explain both effects.
One flow has a K-Ar age of 70±4 My. From the magnetic results on 37 flows, it is concluded that the stable remanence is of primary origin and that its between-fiow dispersion (19°) is due largely to secular variation. The average palaeo-field direction calculated from these flows corresponds to a reverse pole at 62° N, 169° W, with dp= 8°, dm = 9°. This pole agrees with a published Lower Tertiary pole for east Greenland but is displaced from poles of similar age for north-western Europe. This is compatible with an opening of the Norwegian Sea that occurred mainly after these rocks were laid down.
TL;DR: The assay was applied to the measurement of chlorthalidone in human blood and urine, and results suggest that chlortalidone has a long half-life and is extensively metabolized in humans.
TL;DR: An ultrasonic Doppler transducer suitable for intra-esophageal use in humans has been constructed, tested, and its function as a flow monitoring device assessed on a series of 15 unselected anaesthetized human subjects undergoing surgery.
Abstract: An ultrasonic Doppler transducer suitable for intra-esophageal use in humans has been constructed, tested, and its function as a flow monitoring device assessed on a series of 15 unselected anaesthetized human subjects undergoing surgery. Doppler flow signals from the descending thoracic aorta have been obtained in all cases. Once correctly positioned, the probe can give continuous qualitative monitoring of pulsatile aortic blood flow velocity for extended periods. It is possible to observe flow waves in the descending thoracic aorta from the aortic arch distally for about 20 cm and observe the change from disturbed to laminar flow patterns over this length.
TL;DR: Eight rats were successfully trained in a black-white discrimination with a 1-min delay of reward with an unusual procedure in that the rat spent the delay outside the apparatus in its home cage.
TL;DR: The Skinner Cove volcanic rocks, the lowermost of a sequence of thrust slices associated with the Bay of Islands ophiolites of western Newfoundland, make up a continuous alkaline differentiation sequence from pillowed ankaramites to trachytes as mentioned in this paper.
TL;DR: In this article, the formation of a hydraulic jump at an abrupt step is compared to that at a step with a rounded edge, and it is shown that the large standing wave associated with the abrupt step does not form when the step is rounded and that downstream waves can be suppressed.
Abstract: The formation of a hydraulic jump at an abrupt step is compared to that at a step with a rounded edge. It is shown that the large standing wave associated with the abrupt step does not form when the step is rounded and that downstream waves can be suppressed. Measurements of the range of tailwater depths over which the jump is located at the step are given and show only slight dissimilarities with similar measurements taken at abrupt steps. There is little difference in maximum bed velocities, but reversal of bed flow does not occur downstream of the rounded step.