Showing papers by "Laval University published in 1970"
TL;DR: This chapter discusses the influences of the diffuse, unspecific structures (especially involved in wakefulness and sleep states) on the responsiveness of various neothalamocortical systems, and their interactions with the effects induced by stimulating or interrupting the specific pathways.
Abstract: Publisher Summary The concept of unspecific and specific ascending influences exerted on sensory and motor systems is largely an outgrowth of experiments and theories concerning sleep and wakefulness. Thus, to analyze the factors affecting the synaptic transmission of afferent messages through thalamic and cortical neuronal chains, the relay of messages through the motor cortex to the efferent paths, and to correlate some of these physiological activities with perceptual integration at different levels of awareness, it is necessary to present a brief preliminary survey of cerebral systems regulating wakefulness and sleep. That sleep is also because of an active, and not because of a purely passive process, is further indicated by the analysis of unitary and mass evoked responses during stimulation of inhibitory structures or following transections interrupting the ascending inhibitory systems. Likewise, the studies of fluctuations in thalamic and cortical evoked responses during various stages of natural sleep and wakefulness in chronically implanted animals support the hypothesis of an active process. This chapter discusses the influences of the diffuse, unspecific structures (especially involved in wakefulness and sleep states) on the responsiveness of various neothalamocortical systems, and their interactions with the effects induced by stimulating or interrupting the specific pathways.
129 citations
TL;DR: These fibers which lose their cholinesterase activity several weeks after lesions in the caudate nucleus but not after lesions associated with a complete cell loss in the substantia nigra have the same origin, course and termination as the striatopallidal and striatonigral fibers disclosed after silver impregnation in experimental animals.
111 citations
TL;DR: In this paper, a discussion of the total intensities of isovector excitations in nuclei is presented and the relation of these intensities to the excitation strengths to states of definite isospin T, T + 1, and T − 1 is studied and explicit estimates for the case of transitions of the electric dipole type.
88 citations
82 citations
TL;DR: It is concluded that the interruption of the rubro-olivo-cerebello-rubral loop and its interconnections represents an important feature in the appearance of postural tremor.
78 citations
TL;DR: The discussion bears on the phenomena involved in the osmotic adaptation of the muscle cells, the critical evaluation of the methods used and the values reported for the muscle extracellular space, and a brief examination of the results from the standpoint of comparative physiology.
58 citations
TL;DR: In this article, the far-infrared spectra of liquid and solid CH4 and CD4 have been recorded in the 20-200 cm−1 region and the presence of two translational lattice modes in phase II is consistent with the cubic structure with space group T4-P213 and site symmetry C3.
48 citations
TL;DR: Investigation of the localization of intranucleolar DNA in root meristematic cells of Allium cepa following formaldehyde fixation coupled with deoxyribonuclease extraction reveals that most, if not all, of the intranuclear DNA is located inside small lacunar spaces confined to the fibrillar regions of the nucleolar mass.
Abstract: The problem of the localization of intranucleolar DNA in root meristematic cells of Allium cepa has been investigated under both light and electron microscopy following formaldehyde fixation coupled with deoxyribonuclease extraction. The observations reveal that most, if not all, of the intranucleolar DNA is located inside small lacunar spaces confined to the fibrillar regions of the nucleolar mass. These results would be consistent with the view that the DNA-containing lacunar spaces in question correspond, in fact, to cross-sections of a meandering channel containing the extended nucleolar organizing segment of the nucleolar chromosome.
46 citations
TL;DR: It is suggested that the influence transmitted through the spinal dorsal roots does not play an important role in initiating postural tremor, and the rate and rhythm of tremor episodes are uninfluenced by impulses transmittedthrough the dorsal roots which, however, apparently exert a stabilizing effect on the amplitude of the bursts.
Abstract: Rhizotomy of the dorsal roots of the upper limb in lesioned monkeys with lesioned-induced and harmaline-induced tremor caused complete anaesthesia and akinesia of the corresponding limb, which only showed purposeless movements. The rate and rhythm of postural tremor and the reciprocality of the bursts in opposite muscles were not affected by the rhizotomy; the incidence of tremor episodes was greater in some animals. Rhizotomy apparently interfered with the amplitude of the bursts which, at times, was less regular in the deafferented limb. In four out of six animals the rhizotomy involved the blood supply of the dorsal part of the lateral column. This caused a degeneration of the corresponding lateral corticospinal and dorsal spinocerebellar tracts, producing a weakness of the ipsilateral lower limb which gradually improved. Faster bursts (12–13/sec) were also noted on the EMG in response to harmaline in monkeys with cerebellar lesions. These findings suggest that the influence transmitted through the spinal dorsal roots does not play an important role in initiating postural tremor. The rate and rhythm of tremor episodes are uninfluenced by impulses transmitted through the dorsal roots which, however, apparently exert a stabilizing effect on the amplitude of the bursts.
45 citations
TL;DR: Light and electron-microscopic features and electrocardiographic findings of experimentally produced cobalt lesions were strikingly similar to those observed in Quebec beer drinkers' cardiomyopathy.
38 citations
TL;DR: Feeding Tribolium confusum and Tenebrio molitor a 1% reserpine diet drastically suppresses reproduction and evidence for a role of the neuro-endocrine system in the changes observed in the reproductive organs of tranquillized females of T. molitor is suggested.
TL;DR: It is shown that the integrity of the nigrostriatal pathway is essential for the maintenance of DOPA decarboxylase activity at the level of the striatum, which explains the deficient synthesis of dopamine from its immediate precursor l -DOPA in animals whose nigral neurones have degenerated as a result of a specific lesion.
01 May 1970
TL;DR: In this paper, a microwave hologram which was displayed by a cathode-ray tube and recorded on film was constructed and digitized for computer input and calculated the Fresnel transform of the digital microwave holograms using the fast Fourier transform method to reconstruct images of an original object.
Abstract: A microwave hologram which was displayed by a cathode-ray tube and recorded on film was constructed and digitized for computer input. A computer calculated the Fresnel transform of the digital microwave hologram using the fast Fourier transform method to reconstruct images of an original object.
TL;DR: The reported anomalies of the Z-line do not correspond exactly to those previously described in cats and dogs, nor to the rods of the “nemaline myopathy,” and the present findings cannot be explained by the existing theories on the structural organization of theZ-line.
TL;DR: In the process of reconstructing images from sound-wave holograms, optical and numerical reconstructions are investigated and the images reconstructed by the optical and the numerical methods are compared and discussed.
Abstract: Sound-wave holograms are constructed with sound waves of 10 kHz to 20 kHz by two holographic techniques; the coherent background and the electronic reference methods. The acoustical fields, which are scanned by a microphone and displayed by a lamp, are recorded on films as sound-wave holograms. In the process of reconstructing images from sound-wave holograms, optical and numerical reconstructions are investigated. In the optical reconstruction the images are reconstructed by illuminating the reduced hologram with laser light. The images reconstructed from grating-like holograms constructed in sampling-type holography are discussed. The numerical reconstruction of images is conducted by computer calculation of the digital Fresnel transform of sound-wave holograms using the FFT (fast Fourier transform) method. The analog sound-wave holograms recorded on films are divided into meshes of 64 × 64 cells and each cell is digitized into three levels according to the transparency of the film. The images reconstructed by the optical and the numerical methods are compared and discussed. Theoretical analyses are conducted to explain the experimental procedures and the obtained results.
TL;DR: In this paper, the Fourier transform formalism of the sampling theorem in the frequency domain has been used in a coherent optical processor to obtain multiple reproduction of space-limited functions.
Abstract: The Fourier-transform formalism of the sampling theorem in the frequency domain has been used in a coherent optical processor to obtain multiple reproduction of space-limited functions. Some useful results bearing on the physical processes involved have been derived. Experimental results obtained with a simple two-dimensional space-limited function and a practical sampling function have been presented to confirm some of the theoretical predictions. The over-all efficiency of the technique has been briefly discussed and another possible application has been pointed out.
TL;DR: In this article, the broken-pair coupling scheme was proposed for the ground state wave function of the 2 n identical particles system being described by a superposition of n identical J π = 0 + coupled pairs I +, the total configuration space of the shell model was divided into subspaces according to the number of pairs I+ they contain.
TL;DR: In this article, the nature and stability constants of simple and mixed complex-species of copper(II) with hydroxyde and ammonia as ligands have been determined using a new mathematical treatment.
Abstract: Using a new mathematical treatment, the nature and stability constants of the simple and mixed complex-species of copper(II) with hydroxyde and ammonia as ligands have been determined. The solubility curves of CuO in heterogeneous equilibrium have been identified in function of pH only and in function of pH and pNH3tot at 25° and unit ionic strength (NaClO4).
The predominent species in the relatively dilute system limited by the ionic strength are [Cu2+], [Cu(OH)2], [Cu(OH)], [Cu(OH)], [Cu(NH3)], [Cu(NH3)], [Cu(NH3)], [Cu(NH3) (OH)+], [Cu(NH3)3(OH)+] and [Cu(NH3)2(OH)2].
TL;DR: The northern and central HD Range in northeastern Nevada is formed of a succession of six major thrust plates that lie on Mississippian Chainman Shale in the central part and are juxtaposed or lie on Lower Permian quartzites and limestones at the northern end as discussed by the authors.
Abstract: The northern and central HD Range in northeastern Nevada is formed of a succession of six major thrust plates that lie on Mississippian Chainman Shale in the central part and are juxtaposed or lie on Lower Permian quartzites and limestones at the northern end. Each plate has its own characteristic stratigraphy: the lowest plate consists of Ordovician chert unconformably overlain by Mississippian Diamond Peak quartzite; the succeeding three are characterized by thin, leptogeosynclinal, Ordovician-Silurian sections, or by intercalations of eu- and miogeosynclinal facies; the two upper plates have thin Ordovician-Silurian sections unconformably overlain by Pennsylvanian and Permian limestone and clastics. Three new formations have been differentiated in the Ordovician, one in the Silurian, and one in the Pennsylvanian. Directional structures and regional stratigraphic comparisons indicate that the last move of the plates, except the upper one, was in a south-southeasterly direction; more than one direction of movement is recorded within single plates, and rotation of large segments of one or more plates appears to have been common. Structures are the result of thrusting of thin, incompetent sections: imbrications, up- and overthrusting, and folding of the frontal ends of thrusts are common to many tectonic plates. The emplacement of the allochthon occurred in two stages: (a) the Ordovician and Silurian eugeosynclinal rocks were first affected in Late Devonian or Mississippian time by the Antler Orogeny and thrust eastward over the miogeosyncline from a source in southern Oregon or southwestern Idaho; subsequently, an overlap sequence of clastics and carbonates was laid down over them, (b) The allochthonous Ordovician-Silurian rocks and the overlap sequences were moved southeastward from south-central Idaho to their present position in early Mesozoic time prior to the intrusion of the mid-Jurassic Contact Pluton. This last phase of thrusting is possibly one of the earliest phases of deformation recorded in the eastern Great Basin east of the Antler Orogenic Belt and preceeded more extensive late Mesozoic thrusting in the Sevier and Laramide Belts of Utah and Wyoming. The occurrence of eugeosynclinal rocks in northeastern Nevada cannot be attributed directly to Antler thrusting: Mesozoic rethrusting of these rocks is to be considered in evaluating their tectonic history. The eastern limits of the Antler Belt do not extend to northeastern Nevada. The upper thrust plate in the north-central HD Range belongs to a separate tectonic succession in the southern part of the range and was emplaced from a more westerly source in late Mesozoic or Tertiary time.
01 Jan 1970
TL;DR: In this article, the authors developed a robust and comprehensive tool to evaluate the effect on household welfare of different agricultural policies in Tanzania and food price changes, using a two-stage estimation strategy: the shadow price of labour is first estimated and then used to estimate production and demand systems as well as labour market functions.
Abstract: Exogenous shocks to farmers' consumption, production and labour market decisions are rarely considered accurately. For farm households, under labour market imperfections, such decisions are often interlinked. This calls for non-separable agricultural household models. According to this framework, second-order (or behavioural) effects include a direct (i.e., supply or demand reactions due to an exogenous shock) and an indirect (i.e., supply or demand adjustments to the endogenous variations in the shadow wage generated by the exogenous shock) component. Under large price changes or following structural interventions, such as those concerning land redistribution or mechanisation practices, neglecting such second-order effects on consumption and production can bias the final impact on household welfare. The main objective of this study is thus to develop a robust and comprehensive tool to evaluate the effect on household welfare of different agricultural policies in Tanzania and food price changes. A two-stage estimation strategy is adopted: the shadow price of labour is first estimated and then used to estimate production and demand systems as well as labour market functions. These models are subsequently used to simulate the effect on household welfare of a hypothetical 40% increase in the price of cereals and other crops and a hypothetical 10% increase in the hectares of arable land and in the use of ox-ploughs. The results are finally compared with the case in which a separable model is adopted.
TL;DR: The appearance of the ethanol dehydrogenase activity in the presence of ethanol is suppressed by the simultaneous presence of glucose but not of citrate, and cells grown on glucose as a carbon source contain little ethanol dehydration activity, but do contain an enzyme which oxidizes cinnamyl alcohol.
TL;DR: Lamellar bodies are described in the non-ciliated epithelial bronchiolar cells of the normal mouse lung and seem to belong to smooth endoplasmic reticulum, which is related to mitochondria.
Abstract: Lamellar bodies are described in the non-ciliated epithelial bronchiolar cells of the normal mouse lung. They are constituted of smooth concentric membranes, with a cytoplasmic center. They are related to mitochondria. They seem to belong to smooth endoplasmic reticulum. An origin from Golgi elements is discussed.
TL;DR: In this article, an identification procedure for determination of coefficients of pulse transfer function is proposed, which is applicable for the case when measurement noises of input and output are independent of input to a process and the variances of the noises are known only in the form of the ratio.
Abstract: An identification procedure for determination of coefficients of pulse transfer function is proposed. This procedure is applicable for the case when measurement noises of input and output are independent of input to a process and the variances of the noises are known only in the form of the ratio. The noises can be colored. The criterion used for identification is given by extending the mean-square equation error. The optimal estimates are obtained from the eigenvector of a linear operator which corresponds to the least eigenvalue. The theoretical analysis is given and the direction for the practical usage is suggested to use the least-square error criterion.
TL;DR: In this article, the problem of adjectives can be formed from substantives by means of a dental suffix has been examined, and four parts of speech-verb, substantive, adjective, and adverb-have been examined.
Abstract: The problem that provides the subject of the present study has, curiously enough, received little more than a passing glance from most grammarians. Many of them mention that adjectives can be formed from substantives by means of a dental suffix, but none seem to be intrigued by the four aspects of the problem to be examined here. The fact that these aspects of the problem have received little or no attention up to now would in itself justify this study. There is, however, a further and even weightier justification. The problem brings into focus four parts of speech-verb (through the past participle), substantive, adjective and adverb–and so provides an excellent opportunity for observing the relations between these categories. Such a chance should not be missed, especially at a time when not merely the system but the very existence of the parts of speech is being called into question.
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TL;DR: In this article, the Litherland-Ferguson geometry II was used to measure the (αp, γ) angular correlations of the 50Cr(α, pγ)53Mn reaction.
TL;DR: In this paper, shell-model calculations using the Kurath force and the Tabakin separable potential for the residual interactions have been performed to interpret the experimental data now available for the T = 12 states in 5He and 5Li above 16 MeV excitation.
TL;DR: The alveolar macrophage of the cat shares some features with the alveolars of ordinary laboratory mammals and man, mainly a voluminous Golgi zone exhibiting evidence of secretory activity, and the very numerous typical lysosomes appear to be a secretory end product.
Abstract: The alveolar macrophage of the cat shares some features with the alveolar macrophages of ordinary laboratory mammals and man, mainly a voluminous Golgi zone exhibiting evidence of secretory activity. The very numerous typical lysosomes appear to be a secretory end product. They increase in size by a fusion process. At some stage of this process dense periodic structures, crystal-like, become visible in intermediate size lysosomes, which later form heterogeneous crystal-like granules characteristic of the cat's alveolar macrophage.
The crystal-like granules are bounded by a unit-membrane pattern and contain a dense periodic parallel lamellar material (crystal-like) mixed with fluffy amorphous substance and surrounded by a clear homogeneous material. Based on its structure as observed at a high magnification, and its behavior during phagocytosis, this crystal-like material appears to be composed of lipid.
Intra-pulmonary injection of red blood cells was carried out in order to observe the fate of the crystal-like granules during phagocytosis as compared to that of typical lysosomes. Like typical lysosomes the crystal-like granules become reduced in number and undergo incorporation to the phagocytic vacuoles, demonstrating their lysosomal nature.
TL;DR: La progestérone présente dans les tissus de Tribolium confusum (coléoptère) tire probablement son origine de la ration alimentaire puisque la concentration de ce stéroïde est du même ordre de grandeur dans l'insecte and dans the ration alimentsaire.
Abstract: La progesterone presente dans les tissus deTribolium confusum (coleoptere) tire probablement son origine de la ration alimentaire puisque la concentration de ce steroide est du meme ordre de grandeur dans l'insecte et dans la ration alimentaire.
TL;DR: In this article, the solubility of precipitated Cd(OH)2 was determined at 25°C in 1 M NaClO4, as a function of pH and of the ammonia content of the solutions.
Abstract: The solubility of precipitated Cd(OH)2 was determined at 25°C in 1 M NaClO4, as a function of pH and of the ammonia content of the solutions. Formation constants were obtained for the following hydroxo, ammine and hydroxo-ammine complexes: CdOH+, Cd(OH)2, Cd(OH), CdNH, Cd(NH3), Cd(NH3), Cd(NH3) and Cd(OH)2NH3. The solubility product of the hydroxide was also calculated.
The presence of polynuclear species was investigated by titrimetric determinations of the hydrogen ion concentration at constant metal concentration.