Showing papers by "California Institute of Technology published in 1969"
TL;DR: In this paper, the authors examine the process by which common stock prices adjust to the information (if any) that is implicit in a stock split and show that the independence of successive price changes is consistent with a market that adjusts rapidly to new information.
Abstract: There is an impressive body of empirical evidence which indicates that successive price changes in individual common stocks are very nearly independent. Recent papers by Mandelbrot and Samuelson show rigorously that independence of successive price changes is consistent with an "efficient" market, i.e., a market that adjusts rapidly to new information. It is important to note, however, that in the empirical work to date the usual procedure has been to infer market efficiency from the observed independence of successive price changes. There has been very little actual testing of the speed of adjustment of prices to specijc kinds of new information. The prime concern of this paper is to examine the process by which common stock prices adjust to the information (if any) that is implicit in a stock split
4,470 citations
TL;DR: In this paper, the authors predict the character of longitudinal-momentum distributions in hadron collisions of extreme energies, and propose a method to predict the distribution of the longitudinal momentum distribution.
Abstract: Proposals are made predicting the character of longitudinal-momentum distributions in hadron collisions of extreme energies.
1,386 citations
TL;DR: In this article, the authors reported analyses of lead in annual ice layers from the interior of northern Greenland and in annual layers of ice from interior of the Antarctic continent, showing that lead concentrations increase from 0.200 γPb/kg ice today in north pole ice sheets, the sharpest rise occurring after 1940.
746 citations
TL;DR: The simple geometric ideas of plate theory are extended to include some forms of plate evolution as discussed by the authors The most important of these occurs where three plates meet such triple junctions are divided into two groups, stable and unstable, according to whether or not they can retain their geometry as the plates move.
Abstract: The simple geometric ideas of plate theory are extended to include some forms of plate evolution The most important of these occurs where three plates meet Such triple junctions are divided into two groups, stable and unstable, according to whether or not they can retain their geometry as the plates move These ideas suggest an explanation for some of the major changes which have occurred in the North Pacific during the Tertiary
596 citations
TL;DR: Patients whose neocortical commissures have been surgically divided for the control of epilepsy have revealed an organizational differentiation of the hemispheres for perceptual and cognitive functions.
Abstract: WORK carried out during the past few years with patients whose neocortical commissures have been surgically divided for the control of epilepsy has revealed an organizational differentiation of the hemispheres for perceptual and cognitive functions1,2.
575 citations
TL;DR: In this paper, a technique for solving the Hartree-Fock equations is proposed which has the property that the virtual orbitals from the ground state wavefunction are variationally correct approximations to the self-consistent orbitals for the excited states.
516 citations
TL;DR: A theory of mind is suggested in which consciousness, interpreted to be a direct emergent property of cerebral activity, is conceived to be an integral component of the brain process that functions as an essential constituent of the action and exerts a directive holistic form of control over the flow pattern of cerebral excitation.
Abstract: The long-standing assumption in the neurosciences that the subjective phenomena of conscious experiences do not exert any causal influence on the sequence of events in the physical brain process is directly challenged in this current view of the nature of mind and the mind-brain relationship. A theory of mind is suggested in which consciousness, interpreted to be a direct emergent property of cerebral activity, is conceived to be an integral component of the brain process that functions as an essential constituent of the action and exerts a directive holistic form of control over the flow pattern of cerebral excitation.
421 citations
TL;DR: The distribution of residues of various types in histone IV is uneven and suggests a high degree of specificity and a unique conformation, which suggests that the NH2-terminal part of the histone may involve the major binding sites to DNA whereas the COOH-terminAL region appears to be capable of possessing a specific protein conformation.
390 citations
TL;DR: The complete amino acid sequence of pea seedling histone IV has been determined with the tryptic peptides from the maleylated protein and compared to the sequence of calf thymus hist one IV, and similarities and differences are discussed in the context of possible structure-function relationships of histoneIV.
346 citations
TL;DR: In this article, the authors consider the case when the infrared opacity is due to a vapor in equilibrium with its liquid or solid phase, and show that the condensing gas would be a major constituent at all levels in such an atmosphere.
Abstract: Radiative-convective equilibrium models of planetary atmospheres are discussed for the case when the infrared opacity is due to a vapor in equilibrium with its liquid or solid phase. For a grey gas, or for a gas which absorbs at all infrared wavelengths, equilibrium is impossible when the solar constant exceeds a critical value. Equilibrium therefore requires that the condensed phase evaporates into the atmosphere.
Moist adiabatic and pseudoadiabatic atmospheres in which the condensing vapor is a major atmospheric constituent are considered. This situation would apply if the solar constant were supercritical with respect to an abundant substance such as water. It is shown that the condensing gas would be a major constituent at all levels in such an atmosphere. Photodissociation of water in the primordial Venus atmosphere is discussed in this context.
341 citations
TL;DR: In this article, the authors examined the evolution of the core of a supernova by approximating this shell by suitable boundary conditions, and the subsequent hydrodynamic expansion is computed; final velocities of expansion up tov∼20 000 km/sec are found.
Abstract: Stars of intermediate mass (4M
⊙≲M≲9M
⊙) may ignite the12C+12C reaction explosively because of the high degree of electron degeneracy in their central regions. After the exhaustion of helium burning in the core of such stars, a helium-burning shell develops which is thermally unstable. Approximating this shell by suitable boundary conditions, the subsequent evolution of the core is examined quantitatively by standard techniques. An explosive instability due to ignition and detonation of12C+12C develops at a central density ϱc ∼ 2 × 109. Subsequent hydrodynamic expansion is computed; final velocities of expansion up tov∼20 000 km/sec are found. The star is totally disrupted; no condensed remnant is left. Such an explosion may be a plausible model for a significant fraction of supernovae. Investigation of the relevant nuclear reaction network shows that the entire core (M
core∼1.37M
⊙) is processed through12C burning,16O burning and silicon burning. Significant amounts of56Ni are produced. This nucleosynthesis is critically sensitive to the exact central density at which the12C+12C reaction ignites; several factors which affect this critical density are discussed. A brief summary of other supernovae thories which have been expounded in detail is presented for comparison.
TL;DR: It is shown that when chromosomal proteins, principally histones, are dissociated from DNA by 2 m -NaCl and then reassociated by gradient dialysis to low ionic strength, the original chromatin is not reconstituted, but reconstitution by gradientdialysis in the presence of 5 m -urea does result in chromatin equivalent to native by the hybridization-competition criterion.
TL;DR: The poor cleavage of a -Met-Thr- bond in catalase by cyanogen bromide has been improved by modifying the conditions of the reaction by increasing the concentration of the reactants.
TL;DR: A collection of 379 drawings of D. simulans claret gynandromorphs was used in order to analyze the cell lineage of the adult cuticular structures and the marker phenotypes forked bristles or yellow body color were used to trace the male tissue.
Abstract: A collection of 379 drawings of D. simulans claret gynandromorphs, kindly supplied to the authors by Dr. A. H. Sturtevant, was used in order to analyze the cell lineage of the adult cuticular structures. The marker phenotypes forked bristles or yellow body color were used to trace the male tissue. The degree of mosaicism within the different imaginal discs was used to estimate the number of blastoderm nuclei whose descendants form the primitive imaginal discs on each side. The estimates are 23 for the compound-eye-antennal discs, 12 for the wing disc, several for the first and second leg discs and perhaps 1 for each of the prothoracic, third leg and abdominal discs. The frequency with which two parts are separated by sex, one male and one female, is assumed to vary inversely with the closeness of their embryonic descent. In this way were constructed the morphogenetic maps of the relative locations on one side of the embryo of the presumptive head, thoracic and abdominal adult structures. Locations of the presumptive parts within the morphogenetic maps are the same as the relative positions of the parts on the adult surface. Arguments are presented to place the morphogenetic map on the three-dimensional surface of the egg. The data are consistent with the model that the morphogenetic map of the prospective adult structures occupies a medial band along both sides of the embryo surface. Poulson's ('50) ground plan of the egg also places the presumptive larval hypodermis in this location. This model is considered relative to the experimental evidence marking the early embryo stages.
TL;DR: In this paper, the stability of a horizontal layer of fluid heated from below is examined when, in addition to a steady temperature difference between the walls of the layer, a time-dependent sinusoidal perturbation is applied to the wall temperatures.
Abstract: The stability of a horizontal layer of fluid heated from below is examined when, in addition to a steady temperature difference between the walls of the layer, a time-dependent sinusoidal perturbation is applied to the wall temperatures. Only infinitesimal disturbances are considered. The effects of the oscillating temperature field are treated by a perturbation expansion in powers of the amplitude of the applied field. The shift in the critical Rayleigh number is calculated as a function of frequency, and it is found that it is possible to advance or delay the onset of convection by time modulation of the wall temperatures.
TL;DR: Two mutants of Drosophila, tan and ebony, have normal eye pigments but show abnormalities in visual behaviour, and both show in their electroretinograms that the primary photoreception process occurs normally, but genetic defects block the usual consequent neural events.
Abstract: Two mutants of Drosophila, tan and ebony, have normal eye pigments but show abnormalities in visual behaviour. Both show in their electroretinograms that the primary photoreception process occurs normally, but genetic defects block the usual consequent neural events. Ambient light has opposite effects on the two mutants.
TL;DR: In this paper, a phenomenological fit of the data on single-pion photoproduction is presented for laboratory photon energies up to 1.2 BeV. The analysis is carried out in terms of the helicity-amplitude formalism.
Abstract: A phenomenological fit of the data on single-pion photoproduction is presented for laboratory photon energies up to 1.2 BeV. The analysis is made in terms of a simple model in which the photoproduction amplitude consists of three separate contributions: (1) the Born approximation with electric coupling only; (2) Breit-Wigner resonances for which the positions and widths are taken from pion-nucleon scattering data, but whose amplitudes are adjustable parameters; and (3) additional contributions in the low partial waves having $J=\frac{1}{2},\frac{3}{2},\mathrm{and} \frac{5}{2}$. A criterion for success of the model is that these added terms, which are the principal adjustable parameters, should vary smoothly with energy. Most of the resonances found in the phase-shift analysis of pion-nucleon scattering are included in the fit. In particular, there is reasonably good evidence in the photoproduction data for a broad $S$-wave resonance near 1560 MeV. The analysis is carried out in terms of the helicity-amplitude formalism, which is more convenient for this purpose than the conventional representation in terms of multipole amplitudes.
TL;DR: In this article, an experimental and theoretical investigation of the effect of general imperfections on the buckling load of a circular cylindrical shell under axial compression was carried out.
Abstract: An experimental and theoretical investigation of the effect of general imperfections on the buckling load of a circular cylindrical shell under axial compression was carried out.
A non-contact probe has been used to make complete imperfection surveys on electroformed copper shells before and during the loading process up to the buckling load. The data recording process has been fully automated and the data reduction was done on an IBM 7094. Three-dimensional plots were obtained of the measured initial imperfection surfaces and of the growth of these imperfections under increasing axial load. The modal components of the measured imperfection surfaces were also obtained.
The theoretical solution located the limit points of the post-buckled states. A simplified imperfection model was used consisting of one axisymmetric and one asymmetric component. For global buckling the correlation between the theoretical buckling loads and the experimental values was found to be good.
TL;DR: In this article, the isotope shift is expressed in terms of the change in the even moments of the nuclear charge, which is a measure of the relative position of isotopes.
Abstract: Numerical data are presented for the analysis of $K$ x-ray isotope shift experiments for $30\ensuremath{\le}Z\ensuremath{\le}103$. The isotope shift is expressed in terms of the change in the even moments of the nuclear charge. Additional contributions to the isotope shift are briefly discussed.
TL;DR: The algorithm of W. F. Trench for the inversion of Toeplitz matrices is presented with a detailed proof for the case of non-Hermitian matrices.
Abstract: The algorithm of W F Trench for the inversion of Toeplitz matrices is presented with a detailed proof for the case of non-Hermitian matrices The only condition necessary to insure the validity of the algorithm is that all principal minors be nonzero
TL;DR: In this paper, the early thermal history of the Earth is reconsidered with the constraint that core formation occur before the emplacement of the oldest known rock possessing remanent magnetism.
TL;DR: In this paper, the problem of small oscillations of a cylinder of general cross-section in a viscous fluid is formulated in terms of integral equations and numerical solutions of the integral equation are presented for the special case of a ribbon of zero thickness.
Abstract: The problem of small oscillations of a cylinder of general cross-section in a viscous fluid is formulated in terms of integral equations. Numerical solutions of the integral equation are presented for the special case of a ribbon of zero thickness.
TL;DR: In this paper, the angular distribution of the radio-frequency electric field of a short antenna in a plasma in a static magnetic field was observed to vary with incident frequency, cyclotron frequency, and plasma frequency in agreement with simple plasma dielectric theory.
Abstract: We report experimental observation of resonance cones in the angular distribution of the radio-frequency electric field of a short antenna in a plasma in a static magnetic field. The cone angle is observed to vary with incident frequency, cyclotron frequency, and plasma frequency in agreement with simple plasma dielectric theory. We discuss the relationship of these cones to the limiting phase- and group-velocity cones which appear in the theory of plane wave propagation.
TL;DR: In this article, the displacement field is analyzed using multi-integral transforms and an inversion scheme based on the well-known Cagniard technique, which reduces the displacements to single integral and algebraic contributions, each of which is identified as the disturbance behind a specific wave front.
Abstract: The propagation of transient waves in an elastic half-space excited by a traveling normal point load is investigated. The load is suddenly applied and then it moves rectilinearly at a constant speed along the free surface. The displacements are computed for all points of the half-space as well as for all load speeds.
The disturbance is analyzed by using multi-integral transforms and an inversion scheme based on the well-known Cagniard technique. This reduces the displacements to single integral and algebraic contributions, each of which is identified as the disturbance behind a specific wave front. The same solution is valid for all load speeds, even though the wave front geometry varies greatly, depending on the speed of the load relative to the body wave speeds. Moreover, the surface displacements are obtained from the interior ones, but only after the Rayleigh waves are computed by a separate calculation. Then, by taking advantage of the form of the exact solution, wave front expansions and Rayleigh wave approximations are computed for all load speeds.
Several other analytical results are obtained for restricted values of the load speed. In particular, when it exceeds both of the body wave speeds the steady-state displacement field is separated from the transient one and reduced to algebraic form. Also, for the limit case of zero load speed a new representation of the interior displacements for Lamb's point load problem is displayed in terms of single integrals.
TL;DR: Pulsar PSR 0833-45 period decrease and rate of change in period increased between 24 February-3 March 1969, discussing contraction explanation as discussed by the authors, discussed contraction explanation explanation
Abstract: Pulsar PSR 0833-45 period decrease and rate of change in period increased between 24 February-3 March 1969, discussing contraction explanation
TL;DR: The Tonto Forest Seismological Observatory in central Arizona has been used to measure dT/dΔ of direct P waves from 212 earthquakes in the distance range between 30 and 100°, and these data have been inverted to obtain a velocity model for the lower mantle as mentioned in this paper.
Abstract: The extended array at the Tonto Forest Seismological Observatory in central Arizona has been used to measure dT/dΔ of direct P waves from 212 earthquakes in the distance range between 30 and 100°, and these data have been inverted to obtain a velocity model for the lower mantle. Travel times calculated for this model are in good agreement with empirical travel times. The dT/dΔ data from different azimuths and from different focal depths are all in reasonably good agreement with the exception of anomalously large values from earthquakes on the mid-Atlantic ridge. The effect of the core on the measured values of dT/dΔ at distances greater than 90° is shown to be significant, and a correction is made for this effect. A curve fit to the dT/dΔ data contains anomalous regions near the epicentral distances of 34.5, 40.5, 49.5, 59.5, 70.5, and 81.5° which may correspond to increased velocity gradients near the depths of 830, 1000, 1230, 1540, 1910, and 2370 km. PcP times were used to estimate a core radius of 3481 km.
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01 Aug 1969TL;DR: These respond, therefore, to EDTA treatment similarly to ribosomes of the rough endoplasmic reticulum from rat liver, and are presumably engaged in protein synthesis in vivo.
TL;DR: The effect of visual deprivation on synaptic contacts in the visual cortex was studied with the electron microscope and the mean density of synapses supplied by the deprived eye was 20% less than on the control side, the upper levels of the cortex being more affected.
Abstract: The effect of visual deprivation on synaptic contacts in the visual cortex was studied with the electron microscope. The deprivation was achieved by unilateral lid suture in 14-day old white rats before eye opening after which the animals were kept for 8 weeks. The density and the size of synaptic contacts in the upper part of the visual cortex (from the surface of layer II up to V) were estimated. The mean density of synapses of the visual cortex supplied by the deprived eye was 20% less than on the control side, the upper levels of the cortex being more affected. The mean size of synaptic contacts was larger (+7.5%) in the upper levels of the deprived cortex. No right left difference in density and size were found in control animals.