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Showing papers by "Dalhousie University published in 1972"


Journal ArticleDOI

619 citations


Journal ArticleDOI
25 Aug 1972-Nature
TL;DR: The period of the free mode oscillation in the bay is 13.3 h, and this is forced by the lunar M2 tide of the North Atlantic to produce the unusually high tides recorded in the area.
Abstract: Tidal ratios outside and inside the Bay of Fundy/Gulf of Maine system fall into two distinct groups. The period of the free mode oscillation in the bay is 13.3 h, and this is forced by the lunar M2 tide of the North Atlantic to produce the unusually high tides recorded in the area.

261 citations


Journal ArticleDOI
TL;DR: The incidence in this series was found to be 53.2 per cent; it was related to the degree of the patients' oral hygiene, while the age, sex, daily dosage of diphenylhydantoin medication, and duration of treatment did not seem to influence the incidence of hyperplasia.

216 citations


Journal ArticleDOI
TL;DR: This paper found that retrieval time became slower with increasing age, as a result of increased time required to search through the contents of memory and initiate the search and/or generate the response.
Abstract: Tested 3 groups of 10 adults (mean ages, 20, 37.5, and 68.1 yr.) under conditions which permitted ss successfully to register and store a short list of digits for memorization. Results indicate that retrieval time became slower with increasing age, as a result of increased time required to (a) search through the contents of memory, and (b) initiate the search and/or generate the response. (PsycINFO Database Record (c) 2006 APA, all rights reserved)

138 citations



Journal ArticleDOI
24 Mar 1972-Science
TL;DR: Certain human subjects have considerable sensitivity differences in the visual resolution of vertical gratings as compared to horizontal gratings, it is argued that the resolution anisotropies result from early abnormal visual input caused by astigmatism.
Abstract: Certain human subjects have considerable sensitivity differences in the visual resolution of vertical gratings as compared to horizontal gratings. Although only subjects with pronounced ocular astigmatism exhibit this effect, the differences are of neural, rather than optical, origin. It is argued that the resolution anisotropies result from early abnormal visual input caused by astigmatism. This abnormal input permanently modifies the brain.

115 citations


Journal ArticleDOI
TL;DR: In this paper, the authors developed a formalism for mixing due to internal wave shearing, where the vertical shear is spread into a layer growing at just the rate required to maintain the layer Richardson number at a critical value.

113 citations


Journal ArticleDOI
01 May 1972-Cancer
TL;DR: A surface‐localizing heterologous antibody against the mouse Ehrlich ascites carcinoma could be bound to chlorambucil without causing the loss of alkylating activity of chlor Ambucil or interfering with the reactivity of the antibody with tumor cells.
Abstract: A surface-localizing heterologous antibody against the mouse Ehrlich ascites carcinoma could be bound to chlorambucil without causing the loss of alkylating activity of chlorambucil or interfering with the reactivity of the antibody with tumor cells Chlorambucil, when bound to the antibody, was a much more effective tumor inhibitor, both in vitro and in vivo, than chlorambucil or the antibody alone

113 citations


Journal ArticleDOI
TL;DR: Radioactive cadmium (109Cd) and zinc (65Zn) were injected subcutaneously into pregnant rats and, after birth, newborns showed detectable 109Cd only in liver, gastrointestinal tract, and in the brain tissue; after lactation, 65Zn was depleted, whereas 109Cc remained in mammary tissue.
Abstract: Radioactive cadmium (109Cd) and zinc (65Zn) were injected subcutaneously into pregnant rats. More cadmium than zinc was found in the placentae. After birth, newborns showed detectable 109Cd only in liver, gastrointestinal tract, and in the brain tissue. Zinc 65 was present in all newborns’ tissues. During lactation, highest output of 65Zn was in colostrum and, on subsequent days, 65Zn in milk declined rapidly. Cadmium 109 in milk was present in low concentration throughout the lactation period. Rats injected with 109Cd and 65Zn after parturition excreted these isotopes in milk in a similiar pattern. Newborns nursed on radioactive milk showed rapid absorption of 65Zn, whereas 109Cd accumulated primarily in the intestinal tract; a lesser quantity of 109Cd was deposited in the liver. In other organs, only 65Zn was found. The lactating mammary gland contained more 109Cd than 65Zn; after lactation, 65Zn was depleted, whereas 109Cd remained in mammary tissue.

109 citations


Journal ArticleDOI
TL;DR: It is suggested that mammalian organism intracellular Cd-BP apparently acts as biochemical mechanism for sequestration of toxic Cd2+ ions.
Abstract: Rats and mice were injected subcutaneousty with cadmium chloride Cd 109 and zinc chloride Zn 65 Both isotopes concentrated primarily in liver and kidneys Tissue subcellular fractionation showed 70% to 80% 109Cd and 65Zn associated with cytoplasmic soluble fraction Soluble fraction gel filtration revealed most 109Cd was bound to proteins of 11,000 to 12,000 molecular weight; 65Zn was associated mainly with larger sized molecules In rats, two weeks following isotope dose, depletion of 65Zn from cytoplasmic macromolecules was demonstrated; 109Cd remained fixed to cadmium-binding proteins (Cd-BP) By ion-exchange chromatography, Cd-BP was resolved into major components Similar components were separated from human kidney Cd-BP Presence of Cd-BP was noted in humans and monkey liver tissues It is suggested that mammalian organism intracellular Cd-BP apparently acts as biochemical mechanism for sequestration of toxic Cd2+ ions

104 citations


Journal ArticleDOI
TL;DR: It is concluded that the increased efflux of [3H]choline evoked by stimulation probably originates from stores of [2H]ACh synthetized during incubation, which is less with lower concentrations of choline.
Abstract: — To demonstrate release of ACh in the absence of inhibition of cholinesterase, slices of cerebral cortex were incubated with [3H]choline, after which they were placed in a tissue bath for superfusion. Hemicholinium (HC-3) increased the spontaneous efflux of [3H]choline. Electrical stimulation at 4/s increased the efflux of [3H]choline to the same extent whether the slices were stimulated early or late during superfusion. The effect of stimulation on efflux of [3H]choline was abolished by tetrodotoxin and by the absence of calcium. The extent of choline efflux resulting from stimulation, as calculated from the specific radioactivity of the incubation medium, was the same when the slices were incubated with 0.1 or 1.0mM choline, but was less with lower concentrations of choline. We conclude that the increased efflux of [3H]choline evoked by stimulation probably originates from stores of [3H]ACh synthetized during incubation.

Journal ArticleDOI
TL;DR: The fate of the secondary cartilage present on the membrane bones of the embryonic chick has been studied after immobilization, which was transformed into a bone‐like tissue, the matrix losing its acid muco‐polysaccharide, accumulating collagen and undergoing calcification.
Abstract: The fate of the secondary cartilage present on the membrane bones of the embryonic chick has been studied after immobilization. Immobilization was achieved by the in vivo injection of paralysing drugs (tubocurare or decamethonium), by grafting membrane bones onto the chorioallantoic membrane, or by organ-culturing membrane bones in vitro. In all three situations the cartilage was transformed into a bone-like tissue, the matrix losing its acid muco-polysaccharide, accumulating collagen and undergoing calcification. The chondrocytes shrank in size, came to resemble osteoblasts (osteocytes) and acquired alkaline phosphatase activity. In normal development this cartilage is not transformed into bone but is partly replaced by bone and partly converted into a fibrocartilage which forms the definitive articular cartilage. Immobilization prevented this normal sequence. Past studies on the transformation of cartilage to bone are reviewed and are seen to be adaptations of a highly labile tissue to functional demands.

Journal ArticleDOI
TL;DR: It was concluded that in vivo the lactate mobilization limits gluconeogenesis from this source, and methylprednisolone pretreatment greatly potentiated the effect of epinephrine.
Abstract: Rates of glucose and of lactate production, and of gluconeogenesis from lactate were measured in unanaesthetized dogs with indwelling arterial and venous catheters. 2-t-glucose, l (+)-lactate-14C, or the mixture of the two were used as tracers according to the primed, constant infusion technique. Norepinephrine infusion had virtually no effect on carbohydrate metabolism. In the normal dog, epinephrine caused increases in plasma glucose levels (about 50%) and in glucose production (35%); lactate turnover increased nearly fourfold, and gluconeogenesis from lactate increased proportionally, thereby almost tripling the lactate contribution to glucose production. There was a logarithmic correlation between plasma lactate level and lactate turnover and a straight line correlation between lactate turnover and the rate of formation of glucose from lactate. The increase of lactate turnover after lactate infusion alone, and combined with norepinephrine, and after methylprednisolone treatment fitted the straight line correlation. It was therefore concluded that in vivo the lactate mobilization limits gluconeogenesis from this source. methylprednisolone pretreatment greatly potentiated the effect of epinephrine. Plasma glucose was increased to 300–600 mg 100 ml . Glucose production rose to four to eight times normal, and gluconeogenesis from lactate rose to eight to ten times the normal values.

Journal ArticleDOI
TL;DR: Kinetic studies showed that the two p-nitrophenyl substrates tested compete for the active sites on both enzymes, and enzyme structure could not be deduced by fitting with calculated curves.

Journal ArticleDOI
11 Feb 1972-Science
TL;DR: A baited camera has recorded a lysianassid amphipod that is twice as large as the largest Amphipod previously recorded.
Abstract: A baited camera has recorded a lysianassid amphipod that is twice as large as the largest amphipod previously recorded. The locality for this mobile omnivore is the sterile bottom of the eastern North Pacific Ocean, at a depth of 5304 meters.

Journal ArticleDOI
TL;DR: In this paper, trace element data from Baffin island and Greenland tertiary tholeiitic basalts has been used to determine the ratios of K, Rb,87Sr/86Sr REE and U in the two areas.

Journal ArticleDOI
01 May 1972-Cancer
TL;DR: The authors' observations suggest that the cytoplasmic fibrils probably play an important role in psammoma body formation.
Abstract: A rare case of papillary adenocarcinoma of the endometrium with psammoma bodies is reported. Essentially two types of cells constituted the tumor. One type, which was endometrioid in appearance, lined the large glandular structures and their papillary folds. The other type formed small glands and the relatively solid areas. Ultrastructurally, the latter cells appeared undifferentiated and contained prominent juxtanuclear fibrillary aggregates. Our observations suggest that the cytoplasmic fibrils probably play an important role in psammoma body formation.

Journal ArticleDOI
TL;DR: Individuals grew faster, while attaining sexual maturity and terminating growth at a larger size in the second population, and energy produced as gametes exceeded the energy produced due to growth in both populations.
Abstract: One population of Nucella lapillus, under conditions of food shortage, decreased in biomass with an annual production of 5.5 kcal per m2. The second population, with plenty of food, gained biomass and the annual production was 16.7 kcal per m2.

Journal ArticleDOI
TL;DR: Many deep water marine muds, including lower Palaeozoic mudstones from Britain, have thin graded beds in which mud and silt laminae alternate, with the silt becoming finer and less abundant upwards.
Abstract: Many deep water marine muds, including lower Palaeozoic mudstones from Britain, have thin graded beds in which mud and silt laminae alternate, with the silt becoming finer and less abundant upwards. Of the known deep-sea depositional processes, turbidity currents are the most likely cause of such graded laminated beds. The lamination may be produced by alternating cohesive and granular bed conditions. Much more careful examination of laminated fine grained terrigenous sediment is needed.

Journal ArticleDOI
H.K. Wolf1, P.J. MacInnis1, S. Stock1, R.K. Helppi1, P.M. Rautaharju1 
TL;DR: A modified diagnostic program is used in epidemiology studies, based on combined utilization of ECG and clinical information, and the diagnostic program for interpretation of the exercise ECG is based on vector analysis of the ST-segment waveform.

Journal ArticleDOI
TL;DR: This paper showed that pigeons trained on a multiple variable interval, extinction schedule, showed a positive contrast effect by comparison with control groups trained with S + only, provided that the interval between stimulus presentations was short (10 sec), but not when it was long (60 sec).


Journal ArticleDOI
TL;DR: In this article, a procedure for treating low frequency behaviors is described and illustrated by treatment of a case of depression, where the patient is active in all phases of the treatment from selecting and monitoring behaviors and reinforcers to administering the reinforcement contingent upon completing self-prescribed tasks.


Journal ArticleDOI
TL;DR: In planning management, the threat to life is the primary issue to be faced with the best treatment aimed at cure or longterm control having priority, and disfigurement caused by tumors around the eye forms the secondary priority.
Abstract: To most of us sight is the most precious of the senses. Tumors of the eye and orbit can be life threatening, cause blindness and be disfiguring. In planning management, the threat to life is the primary issue to be faced with the best treatment aimed at cure or longterm control having priority. Fortunately we have two eyes and the loss of vision in one does not prevent a person from living a normal life. Disfigurement caused by tumors around the eye is more serious than in any other part of the body, and this, together with preservation, forms the secondary priority. Radiotherapy can produce a high cure rate with good cosme sis and preservation of vision but is in danger of becoming a lost medical art (Fitzpatrick 1995, Schlienger et al. 1996).

Journal ArticleDOI
TL;DR: Dieser Beitrag stellt die erste eingehende Studie über die Mikroanatomie je einer typischen solitären and koloniebildenden Art des GenusStephanoscyphus dar, das der Scyphozoenordnung Coronatae angehört.
Abstract: 1. A solitary and a branched (colonial) species ofStephanoscyphus belonging to the scyphozoan order Coronatae were studied by means of histochemistry, light microscopy and by transmission and scanning electron microscopy. 2. Coronate polyps are unlike all other cnidarian polyps in having a ring sinus in the oral end with four per-radial openings to the coelenteron. 3. The lining of the lateral wall of the ring sinus is remarkable in that the cells are so large, most of the cytoplasm is taken up by a large vacuole, the nucleus is apical and between some of the cells are unbranched elastic fibers aligned at right angles to the epithelial surface. 4. The organization of the muscular system is also peculiar because much of it is related to the ring sinus. Musculo-epithelia from the oral disk and medial sinus wall meet and continue aborally as four flattened tubular retractors containing cnidoblasts. 5. In the colonial species some muscle fibers contain structures resembling ciliary rootlets. 6. The intermediate layer is of the mesolamella type. 7. The tentacles have longitudinal ectodermal epithelio-muscular cells and a solid core composed of a single line of vacuolated endodermal cells which contain peripheral fibrous rings. 8. The medial sinus wall and the epithelia of the calyx can be less than 0.1µm. 9. The ectoderm and endoderm of the calyx-stalk are each composed of one cell type. This is the simplest organization for the body wall of any cnidarian polyp. 10. There are four small septa in the oral region. 11. Four special cellular bands, called filaments, are found in the coelenteron starting in the oral disk then travelling along the edge of the septa finally going aborally along the stalk. In the oral region the filament is round in cross-section then flattens out aborally. 12. The neurites are typically cnidarian (neurotubules, granular vesicles but noSchwann cells) and were noted in the filaments and retractor muscle tubes but the tentacles lacked neurites. 13. Teeth are formed only after 4µm of the periderm are laid down. Next the soft-body invaginates at the tooth site and then the ectoderm secretes the tooth periderm. 14. The tubal periderm thickens at 0.6µm per day and stops when it reaches about 20µm. 15. An experimental hole in the periderm is not filled in but the bottom is covered over by new periderm which would have been secreted anyway in an intact polyp. The ectoderm over the hole thickens but histochemistry failed to show anything definite. 16. The periderm can be divided into two layers: the 4µm outer sulptured layer is formed by a special thick band of ectoderm at the oral end of the calyx; the thicker part of the periderm is smooth and is formed by the ectoderm of the calyx and stalk. 17. The cytological peculiarities, comparative anatomy and functional morphology are discussed.

Journal ArticleDOI
TL;DR: 3/He4He measurements at two stations in the Atlantic have shown that the deep water (> 2 km) contains far less excess 3/He than the Pacific Ocean as mentioned in this paper.

Journal ArticleDOI
TL;DR: Animals permitted free access to a running wheel and drinking tube increased the amount of running when drinking was punished with electric shock, and questions an interpretation of the increase in unpunished alternative responding based upon its avoidance properties.
Abstract: Animals permitted free access to a running wheel and drinking tube increased the amount of running when drinking was punished with electric shock. Additional experiments demonstrated that the simple presence or absence of a drinking tube (or running wheel) was a sufficient condition to observe a decrease or an increase in the alternative response. A quantitative analysis of these interactions observed between the incompatible running and drinking responses suggested that each response occupied a constant proportion of the time available for it. These results question an interpretation of the increase in unpunished alternative responding based upon its avoidance properties.

Journal ArticleDOI
04 Aug 1972-Nature
TL;DR: The development of subduction zones may depend on the motion of the two converging lithospheric plates relative to the underlying deep mantle as mentioned in this paper, and it is likely that the plates move much more rapidly than the underlying mantle, the return flow being diffused through a large region
Abstract: THE development of subduction zones may depend on the motion of the two converging lithospheric plates relative to the underlying deep mantle. It is likely that the plates move much more rapidly than the underlying mantle1–4, the return flow being diffused through a large region1,5. The deep mantle is thus nearly stationary and the horizontal motion of sinking plates that extend to depths of 700 km must be significantly restrained.

Journal ArticleDOI
TL;DR: Gene and genotype frequencies in a polymorphic esterase isoenzyme system were measured in collections of the brittle-star Ophiomusium lymani taken at approximately 2000 meters off the coast of North Carolina.