Showing papers by "Carleton University published in 1968"

Hitological studies on the genus Fucus. 3. Fine structure and possible functions of the epidermal cells of the vegetative thallus.

Abstract: The fine structure of the epidermal cells of the vegetative Fucus thallus has been examined in material fixed with acrolein. These cells are highly polarized, with basal nuclei and chloroplasts, a hypertrophied perinuclear Golgi system, and a much convoluted wall/plasma membrane interface. Much of the intracellular volume is occupied by single membrane-bounded vesicles containing alginic acid, fucoidin and polyphenols. The chloroplasts were examined by light and electron microscopy and shown to contain structured inclusions not previously described in Fucus plastids. It is suggested on the basis of their morphology that the epidermal cells may be specialized for the absorption of inorganic carbon and sulphate from the outside of the plant and for the secretion of alginic acid, fucoidin and polyphenols. The possible role of these cells in the prevention of desiccation and in osmoregulation is discussed.

Histological studies on the genusFucus II. Histology of the reproductive tissues

Abstract: 1. The histology of the reproductive tissues ofFucus edentatus De la Pyl. was examined with the light microscope using new preparative methods which facilitate a high resolution of cellular and extracellular detail. 2. By the use of toluidine blue staining and the periodic acid-Schiff's reaction the polysaccharides alginic acid and fucoidin were localized, both within cells and in the extracellular matrices. 3. The synthesis and secretion of fucoidin and alginic acid were followed, particularly in the developing oogonia where each of these polysaccharides are synthesized in different regions of the cells and secreted at different times during development. 4. Developing oogonia show changes in nuclear morphology and staining properties. A progressive decrease in nuclear basophilia from the 1-nucleus stage to that of the mature egg is paralled by a progressive increase in the acidophilia of the same nuclei. Changes also occur during development in the polyphenolic components of the oogonia. 5. The changes in polysaccharide synthesis and secretion, and in the nuclei during oogonial development are discussed in the light of related observations in both plant and animal systems.

Effects on pupil size of manual and verbal indicators of cognitive task fulfillment

Abstract: A total of20 Ss attempted to generate images to concrete and abstract stimulus words while pupillary activity was continuously photographed. One group (N =5) was required to press a key when an image occurred, a second to describe the image, and a third to press a key as well as describe the image. No overt indicator was required of a fourth group. Results showed that greater dilation occurred during the imagery task than during a control period only in those conditions in which an overt response indicated task fulfillment. Consistent with earlier findings significantly greater dilation occurred to abstract than concrete stimulus words in the key press condition.

Experimental Observation of an Antisymmetric Raman Scattering Tensor

Abstract: IT is well known that the scattering tensor for vibrational Raman scattering is symmetric1. This is, however, not true for electronic Raman transitions (refs. 1, 2 and unpublished results), and this has important implications in the selection rules for these transitions.

Analysis of Unbraced Multistory Steel Rigid Frames

Abstract: A compatibility method of analysis is developed for the study of the inelastic in-plane behavior of multistory steel rigid frames subject to sidesway. The method provides for the following conditions to be satisfied throughout the frame simultaneously: (1) The internal forces are in equilibrium with the external forces on the deflected frame; (2) the curvature of each portion of each member satisfies the appropriate nonlinear moment-thrust-curvature relationship; and (3) the distortions of all the parts satisfy the condition of continuity of the frame. The analysis is obtained by successive approximations. A special technique is developed to facilitate the analysis at the condition of ultimate load, and in the early stages of instability of the frame. Good agreement is obtained with tests conducted by others on three full-scale frames.

Electronic Raman Spectra. III. Absolute Cross Sections for Electronic Raman and Rayleigh Scattering

Abstract: Absolute cross sections for Rayleigh and electronic Raman scattering of trivalent rare-earth ions have been calculated. A comparison with the experimental cross section for benzene reveals that both the Rayleigh and Raman scattering for the lanthanides is weaker by more than two orders of magnitude. The Rayleigh-to-Raman ratio is shown to be a rapidly fluctuating function of the electronic structure of the lanthanide ions.

On a Discrete Analogue of Inequalities of Opial and Yang

Abstract: Let be a non-decreasing sequence of non-negative numbers, and let U∘=0. Then we have Yang [3] proved the following integral inequality: If y(x) is absolutely continuous on a≤x≤X, with y(a) = 0, then

Electronic raman spectra. iv. relation between the scattering tensor and the symmetry of the crystal field

Abstract: The scattering tensor for the 7F1–7F0 and 7F2–7F0 electronic Raman transitions of the trivalent europium ion has been calculated for cases in which the rare-earth ion experiences a crystal field of cubic, hexagonal, and tetragonal symmetry. It is shown that such crystal fields give rise to Raman spectra of which polarization features are direct indications of the symmetry of the environment. The 7F1←7F0 transitions are all related to the antisymmetry of a scattering tensor, whereas the 7F2←7F0 transitions are related to a symmetric tensor. According to theory, the latter transitions should be more intense than the former.

Magnitude and latency of the pupillary response during an imagery task as a function of stimulus abstractness and imagery ability

Abstract: The Ss who differed in imagery ability according to scores on a test battery were asked to generate mental images suggested by concrete and abstract stimulus words. Pupillary reactions were continuously photographed during the task. The results showed no significant effects attributable to imagery ability. Imaging to words was associated with dilation and maximum dilation occurred sooner when the stimulus was concrete than when it was abstract, but pupil size was relatively unaffected by abstractness. The findings suggest that pupillary response latency may be more sensitive than magnitude as an indicator of cognitive-task difficulty.

Laser-induced phonon spectrum of an oriented crystal of thulium gallium garnet,

Abstract: Polarized low-temperature laser-excited Raman spectra of the compound thulium gallium garnet are reported. The orientation of the cubic crystal was such that the direction of propagation of the incident laser beam was not parallel to either the a, b, or c axis and in order to assign the Raman spectrum, the scattering tensor had to be rotated. All internal modes of the GaO4 group of Tm3Ga2(GaO4)3 could be assigned and several external vibrations.

New Developments in Raman Spectroscopy with Lasers: Electronic Transitions:

Abstract: A discussion is given of the Raman spectra of single crystals of yttrium gallium garnet (YGaG), of ytterbrium gallium garnet (YbGaG), and of Yb:YGaG. From a comparison of the spectra it has been possible to separate the phonon spectra of the host lattices from that of an electronic Raman effect which occurs between the crystal field levels of the 2F7/2 manifold of Yb3+ in the garnet crystals. Information with respect to the selection rules governing both types of spectra is given.

Geochemistry of Some Large Canadian Craters

Abstract: PETROGRAPHIC criteria have been applied to large and complex structures containing rocks of igneous appearance in attempts to prove an impact origin of these structures1,2 Discovery of alkaline and carbonatitic rocks in the Brent crater3, widely accepted as a holotype of “fossil” impact sites, throws serious doubt on petrographic criteria of origin We have therefore examined four large craters on the Canadian shield by geochemical methods The locations and diameters of these structures are as follows–East Clearwater (56° 05′ N, 74° 45′ W), 14 miles; West Clearwater (56° 10′ N, 74° 45′ W), 19 miles; Carswell (58° 27′ N, 109° 30′ W), 24 miles; Manicouagan (51° 25′ N, 68° 30′ W), 38 miles All four structures4 are roughly circular basins having a depth less than 1 per cent of the diameter, and with a concentric central prominence The basin is almost circular at West Clearwater and Carswell quadrate at East Clearwater and octagonal at Manicouagan Rocks of igneous appearance outcrop on the edges of the central prominence and (except at Carswell, in the lowest parts of the basin Volumes of igneous rocks range from less than 001 miles3 at Carswell to more than 20 miles3 at Manicouagan Both dyke-like and sheet-like masses are present–the latter greatly predominant in volume The lower parts of the sheets are rich in inclusions, and locally consist of unusual breccias (suevite) which are also found as dykes

Latency and magnitude of the pupillary response during an imagery task

Abstract: Pupillary reactions were continuously photographed while Ss attempted to generate images suggested by stimulus words The nouns represented three levels of task difficulty in terms of the rated ease with which the words evoke sensory images Ss were required to press a key when an image occurred as well as subsequently describe the image The results showed a significant increase in pupil size during the imagery task, but differential amounts of dilation were not exactly related to the three levels of task difficulty, whereas the time to maximum dilation was, suggesting that latency of dilation is a more sensitive index of difficulty in the imagery task

Virgines Subintroductae in Celtic Christianity

Abstract: Several years before his death the Irish novelist and playwright, George Moore, wrote his “one joyous book,” A Story Teller's Holiday Combining “oddments of folklore” and the “rich Anglo-Irish idiom,” Moore traced in Boccaccian fashion the ancient Christian practice of syneisactism in early Celtic Christianity. In his work Moore was admittedly stimulated by the great Celticist, Kuno Meyer, and by the then burgeoning translations of ancient Irish manuscripts describing syneisactism.

Reception of pulse-amplitude-modulated signals transmitted over a dispersive fading channel with nonstationary statistics

Abstract: The optimum linear receiver is described for the reception of PAM signals over a dispersive, randomly time-varying channel which causes intersymbol interference. For a wide-sense stationary channel the receiver is relatively simple. The results also apply to the reception of multiplexed signals where the modulation scheme is linear.