Showing papers by "Cornell University published in 1977"
TL;DR: In this paper, a broader approach to research in human development is proposed that focuses on the pro- gressive accommodation, throughout the life span, between the growing human organism and the changing environments in which it actually lives and grows.
Abstract: A broader approach to research in hu- j man development is proposed that focuses on the pro- \ gressive accommodation, throughout the life span, between the growing human organism and the changing environments in which it actually lives and grows. \ The latter include not only the immediate settings containing the developing person but also the larger social contexts, both formal and informal, in which these settings are embedded. In terms of method, the approach emphasizes the use of rigorousj^d^igned exp_erjments, both naturalistic and contrived, beginning in the early stages of the research process. The chang- ing relation between person and environment is con- ceived in systems terms. These systems properties are set forth in a series of propositions, each illus- trated by concrete research examples.
7,980 citations
5,833 citations
TL;DR: The creation, elaboration, and functions of boundary spanning roles are examined, with attention to environmental and technological sources of variation in the structure of boundary roles.
Abstract: Boundaries are a defining characteristic of organizations, and boundary roles are the link between the environment and the organization. The creation, elaboration, and functions of boundary spanning roles are examined, with attention to environmental and technological sources of variation in the structure of boundary roles. Eleven hypotheses integrate the material reviewed and are amenable to empirical test. Future research should overcome problems created when organizations are treated as “wholes” or single entities.
1,311 citations
TL;DR: Alcohol treatment in addition to formalin fixation does not affect results with this method, it should be useful to researchers who want to study the cartilage or cartilaginous skeletons in museum specimens, which are routinely fixed in formalin and stored in alcohol.
Abstract: Preparation of small vertebrates cleared after alcian blue staining of cartilage is facilitated by trypsin digestion. Specimens are fixed in formation, washed, skinned, and eviscerated. After staining in a solution of alcian blue in acetic acid-alcohol for 24-48 hours, they are transferred to water through graded alcohols. Excess alcian blue is removed over a period of up to three weeks by changes every 2-3 days of 1% trypsin in approximately one-third-saturated sodium borate. Bony tissues may be stained after this in a solution of alizarin red S in 0.5% KOH. Specimens are bleached if necessary and dehydrated through graded KOH-glycerine mixtures for storage in glycerine. Since alcohol treatment in addition to formalin fixation does not affect results with this method, it should be useful to researchers who want to study the cartilage or cartilaginous skeletons in museum specimens, which are routinely fixed in formalin and stored in alcohol.
1,246 citations
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TL;DR: In this article, an elaboration and defense of the interaction view of metaphor is presented. But the focus is on the explication of the metaphors used in the earlier account, and not on the ontological status of metaphors.
Abstract: Summary
An elaboration and defense of the “interaction view of metaphor” introduced in the author's earlier study, “Metaphor” (1962). Special attention is paid to the explication of the metaphors used in the earlier account.
The topics discussed include: selection of the “targets” of the theory; classification of metaphors; how metaphorical statements work; relations between metaphors and similes; metaphorical thought; criteria of recognition; the “creative” aspects of metaphors; the ontological status of metaphors.
Metaphors are found to be more closely connected with background models than has previously been recognized.
946 citations
TL;DR: In this article, three types of homogeneous anisotropic turbulence were produced by the plane distortion, axisymmetric expansion and axisymetric contraction of grid-generated turbulence, and their behaviour in returning to isotropy was experimentally studied using hot-wire anemometry.
Abstract: Three types of homogeneous anisotropic turbulence were produced by the plane distortion, axisymmetric expansion and axisymmetric contraction of grid-generated turbulence, and their behaviour in returning to isotropy was experimentally studied using hot-wire anemometry. It was found that the turbulence trajectory after the plane distortion was highly nonlinear, and did not follow Rotta's linear model in returning to isotropy. The turbulence wanted to become axisymmetric even more than it wanted to return to isotropy. In order to show the rate of return to isotropy of homogeneous turbulence, a map of the ratio of the characteristic time scale for the decay of turbulent kinetic energy to that of the return to isotropy was constructed. This demonstrated that the rate of return to isotropy was much lower for turbulence with a greater third invariant of the anisotropy tensor. The invariant technique was then applied to the experimental results to develop a new turbulence model for the return-to-isotropy term in the Reynolds stress equation which satisfied the realizability conditions. The effect of the Reynolds number on the rate of return to isotropy was also investigated and the results incorporated in the proposed model.
673 citations
TL;DR: In this article, a polar orbiting satellite was used to measure spatially confined regions of extremely large electric fields in the auroral zone at altitudes below 8000 km, which are identified as paired electrostatic shocks which are associated with electrostatic ion cyclotron wave turbulence.
Abstract: dc and ac plasma-density and vector-electric-field detectors on a polar orbiting satellite have measured spatially confined regions of extremely large (\ensuremath{\sim}\textonehalf{} V/m) electric fields in the auroral zone at altitudes below 8000 km. Such regions frequently have double structures of opposing electric fields containing characteristic and different wave spectra internal and external to themselves. These structures are identified as paired electrostatic shocks which are associated with electrostatic ion cyclotron wave turbulence.
671 citations
TL;DR: In this paper, the Metropolis Monte Carlo method is used to sample the square of an antisymmetric wave function composed of a product of a Jastrow wave function and a number of Slater determinants.
Abstract: The Metropolis Monte Carlo method is used to sample the square of an antisymmetric wave function composed of a product of a Jastrow wave function and a number of Slater determinants. We calculate variational energies for $^{3}\mathrm{He}$ and several models of neutron matter. The first-order Wu-Feenberg expansion is shown always to underestimate the energy, sometimes seriously. The phase diagram for ground-state Yukawa matter is determined. There is a class of Yukawa potentials which do not lead to a crystal phase at any density.
519 citations
TL;DR: In this paper, the Euclidean partition function of Abelian lattice (gauge) theories in various dimensions was studied using generalizations of mathematical methods developed recently to study the XY model in two dimensions and physical pictures of the phases of these more complicated theories.
504 citations
TL;DR: In this paper, a new algorithm is presented for the molecular dynamics simulation of rigid polyatomic molecules, which consists of solving the eulerian rigid body equations using quaternions to represent orientations, by a fifth-order predictor corrector method.
Abstract: Using a transformation of the rigid body equations of motion due to Evans [4], a new algorithm is presented for the molecular dynamics simulation of rigid polyatomic molecules. The algorithm consists of solving the eulerian rigid body equations, using quaternions to represent orientations, by a fifth-order predictor corrector method. Compared to previous methods, it is shown that this algorithm leads to an order of magnitude increase in computing speed.
TL;DR: Although mosaic phenomena are general, two broad groupings may be recognized: intracommunity patterns that relate to microsite differentiation and species response to this, and intercommunity successional mosaics and climax complexes for which community disturbance is a major determining force.
TL;DR: Theorem 4.7 is similar to a known result which can be found in [10, 11] and as discussed by the authors, and the results proved in this paper will require some familiarity wkh the concepts introduced in [3].
TL;DR: This paper found that people who form their attitudes on the basis of direct behavioral interaction with the attitude object will demonstrate significantly greater attitude-behavior consistency than individuals whose attitudes were formed by other means.
TL;DR: The optical MTF of the authors' subjects’ eyes is computed and it is found that the role of aberrations in degrading the MTF may be greater than generally believed.
Abstract: We have designed an aberroscope that differs from Tscherning’s classical instrument in that it makes use of an artificial astigmatism rather than an artificial myopia to defocus the image of a point source of light. A subject views the source through a ±5 D crossed cylinder lens with axes at 45° to the principal axes of an intercalated grid and sees a shadow image of the grid. The distortions of this grid image are quantitatively related to the wave aberration of the eye. Using this device we have obtained drawings for more than 50 subjects. These drawings of the grid pattern have been analyzed by means of a two-dimensional polynomial curve Fitting technique that computes Taylor polynomial terms to the fourth order. From the Taylor coefficients it is possible to reconstruct the wave aberration surface. Examination of the Taylor terms so obtained shows that the monochromatic aberrations of the eye are dominated by third-order Taylor terms within the range of physiological pupil sizes, and that spherical aberration frequently appears predominantly about one axis only, a condition that we have termed “cylindrical” aberration. We have computed the optical MTF of our subjects’ eyes and find that the role of aberrations in degrading the MTF may be greater than generally believed.
TL;DR: In situ labelling with 14CO2 of the whole crop canopy at frequent intervals before and after anthesis would seem to be the least equivocal way of estimating P1, the pre-anthesis assimilate contribution to grain yield, which is determined in wheat and barley.
Abstract: Reserves of assimilate present in wheat and barley crops a flowering, and available for later translocation to the grains could buffer grain yield against environmental stresses durin; grain filling. This so-called pre-anthesis assimilate contributioi to grain yield can be expressed as a percentage of yield (Pj Archbold1, and later Thome2, concluded. that Px was small being no more than 20%2. But only one result (12 % for irrigate! wheat at Cambridge3) refers to a crop in the field as distinc from plants in pots, and no studies considered the effect o stress during grain filling. Recently Gallagher et a/.4,B reports substantial contributions: Px averaged 43% over six crops o wheat and barley at Nottingham; this amounted to more thai 300 g per ms of dry material in two crops and, in the sever drought of 1970, 39% of total dry matter present at anthesis They assumed, with some supporting evidence from one bade; crop8, that the pre-anthesis contribution was given by th decrease from anthesis to maturity in dry weight of non-graii parts of the crop. In situ labelling with 14C02 of the whole croj canopy at frequent intervals before and after anthesis woul« seem to be the least equivocal way of estimating Px. Using thi method we have determined i\ in wheat and barley. It averagei only 12% (watered crops) and 22% (draughted crops), and di* not agree with estimates for the same crops obtained by th method of Gallagher et a/.**6.
TL;DR: In this article, the Lattman metric is shown to be a scalar multiple of the metric tensor which arises naturally from the Jacobi formulation of the action principle for spherical tops.
Abstract: New sets of variables are studied which should lead to significantly improved numerical stability and efficiency for computer stimulation studies of rigid classical molecules. The search for these new variables is made by finding variables which lead to the simplest (i.e. euclidean) expressions for the metric tensor of orientation space. It is shown that the intuitively defined Lattman metric [1] is a scalar multiple of the metric tensor which arises naturally from the Jacobi formulation of the action principle for spherical tops. It is then shown that Euler's quaternion parameters lead to a euclidean form for the orientation metric. These parameters lead to many associated simplifications in the equations of motion of classical rigid bodies including the removal of singularities and spurious behaviour near θ = 0. It is felt that these benefits will translate into increased accuracy and efficiency both for numerical integration of the equations of motion and for performing Monte Carlo integrations of phas...
TL;DR: In this article, the axisymmetric and spiral vortex breakdowns to imposed flow transients reported previously are confirmed, and are traced to the shedding of starting and stopping vortices from swirl vanes.
Abstract: Flow visualization studies and laser Doppler anemometer measurements on swirling water flows reveal six distinct types of very large amplitude disturbance modes of the vortex core. Three, ’’axisymmetric’’ and spiral vortex breakdowns, and the ’’double helix,’’ have been described by others. A definite order of evolution in parameter space (Reynolds number and circulations) occurs, and is described. Puzzling responses of the axisymmetric and spiral vortex breakdowns to imposed flow transients reported previously are confirmed here, and are traced to the shedding of starting and stopping vortices from swirl vanes. Conclusions bearing upon the validity of some theories of vortex breakdown are possible from the data.
TL;DR: In this article, the infrared interferometric spectrometer (IRIS) data collected by the Mariner 9 spacecraft during the global Martian dust storm of 1971-1972 is analyzed to study the particle sizes in detail, estimate the dust particle size distribution, and determine the dust optical depth.
TL;DR: The authors showed that the unstandardized coefficient and the t-test for the product term are unaffected by the addition of arbitrary constants to the variables in the model, indicating that some hypotheses relating to interaction are not meaningfully testable unless variables are measured on ratio scales.
Abstract: Contrary to a recent claim, the inclusion of a product term in a multiple regression is a legitimate way to test for interaction. The unstandardized coefficient and the t-test for the product term are unaffected by the addition of arbitrary constants to the variables in the model. Certain other statistics are affected by this change, however, indicating that some hypotheses relating to interaction are not meaningfully testable unless variables are measured on ratio scales.
TL;DR: HLA genotyping of parents and children in six families in which more than 1 child had C.A.H.H established that the gene responsible for 21-hydroxylase deficiency is closely linked to HLA.
TL;DR: In this article, wheat flour with up to 20% cowpea (Vigna sinensis) powder, but not 30%, produced breads acceptable to a Nigerian and mixed member taste panel.
Abstract: Wheat flour extended with up to 20% cowpea (Vigna sinensis) powder, but not 30%, produced breads acceptable to a Nigerian and mixed member taste panel. Progressive substantial decrease in loaf volume occurred as cowpea powder level increased beyond 10% but could be minimized by including either 1.0% calcium stearoyl-2-lactylate, sodium stearoyl-2-lactylate, diacetyl tartaric acid ester of monglyceride, or 1.0% calcium stearoyl-2-lactylate plus 0.43% polysorbate in the bread formula. Most bread quality attributes, including acceptable flavor and loaf volume, decreased rapidly when flour blends containing 20% cowpea powder were stored at 30°C. Similar blends at 22°C for at least 12 wk produced acceptable breads, and loaf volume potential of 20% cowpea powder blends decreased only 6–9% at 22°C in 18 wk. Blends containing 10% cowpea powder performed essentially as well as unblended wheat flour initially and better than 20% blends throughout storage.
TL;DR: Some clinical features of hypoactive sexual desire are described, and some hypotheses about etiology and prognosis are presented.
Abstract: The sex therapy literature has concentrated on disorders of the excitement and orgasm phases of the sexual response. However, disorders of sexual desire have been virtually neglected, although low-libido disorders are highly prevalent, may be extremely distressful to patients and their partners, and influence the course and prognosis of therapy. This paper focuses on this important aspect of human sexuality. Some clinical features of hypoactive sexual desire are described, and some hypotheses about etiology and prognosis are presented.
TL;DR: The larval rates of consumption of biomass, energy, and nitrogen were the same for all treatments, indicating that leaf water affected larval growth primarily by restricting the efficiency of utilizing these nutrients.
Abstract: Hyalophora cecropia larvae were reared on leaves of wild cherry,Prunus serotina, which contained variable amounts of leaf water but otherwise did not differ in fiber, total nitrogen, and caloric content. Larvae which were fed leaves low in leaf water grew more slowly and were less efficient at utilizing plant biomass, energy, and nitrogen than those larvae fed leaves which were fully supplemented with water. Experiments were performed using excised leaves under different regimes of relative humidity and leaf water supplementation in climatic control chambers maintained at identical temperatures and photoperiod. Foodplant biomass utilization efficiencies were severely reduced by decreasing amounts of leaf water. Growth rates were halved and the efficiency of conversion of assimilated dry matter into larval biomass was reduced from 82% in the treatment with fully supplemented leaves to 34% in the driest treatment. The nitrogen utilization efficiency (N.U.E.) was reduced from 75–80% to 48%, and the relative accumulation rate of nitrogen (N.A.R.) was suppressed nearly 2-fold for larvae on low-water leaves. Relative maintenance costs (calories expended in respiration/mg tissue/day) of larvae were nearly five times higher on dry leaves than on fully supplemented leaves. Larvae on leaves which were low in water content were themselves more desiccated, and metabolized greater portions of assimilated energy, perhaps in an attempt to supplement body water with metabolic water derived from respiration. The larval rates of consumption of biomass, energy, and nitrogen were the same for all treatments, indicating that leaf water affected larval growth primarily by restricting the efficiency of utilizing these nutrients. Where water was limiting (as in tree leaves), an increased consumption rate did not appear to be a successful means of increasing growth rates. There were daily and seasonal differences in leaf water content between different trees of the same species. Although absolute differences in leaf water exist between different trees and between young and old (fully expanded) leaves of a single tree, these differences are proportional and parallel each other through daily and seasonal cycles. In spite of evolutionary adaptations of herbivores to acquire adequate water and avoid desiccation, the leaf water content naturally encountered by cecropia larvae on cherry leaves may limit their growth, especially if the R.H. is low.
20 Jul 1977
TL;DR: In this paper, a polygon hidden surface and hidden line removal algorithm is presented, which recursively subdivides the image into polygon shaped windows until the depth order within the window is found.
Abstract: A polygon hidden surface and hidden line removal algorithm is presented. The algorithm recursively subdivides the image into polygon shaped windows until the depth order within the window is found. Accuracy of the input data is preserved.The approach is based on a two-dimensional polygon clipper which is sufficiently general to clip a concave polygon with holes to the borders of a concave polygon with holes.A major advantage of the algorithm is that the polygon form of the output is the same as the polygon form of the input. This allows entering previously calculated images to the system for further processing. Shadow casting may then be performed by first producing a hidden surface removed view from the vantage point of the light source and then resubmitting these tagged polygons for hidden surface removal from the position of the observer. Planar surface detail also becomes easy to represent without increasing the complexity of the hidden surface problem. Translucency is also possible.Calculation times are primarily related to the visible complexity of the final image, but can range from a linear to an exponential relationship with the number of input polygons depending on the particular environment portrayed. To avoid excessive computation time, the implementation uses a screen area subdivision preprocessor to create several windows, each containing a specified number of polygons. The hidden surface algorithm is applied to each of these windows separately. This technique avoids the difficulties of subdividing by screen area down to the screen resolution level while maintaining the advantages of the polygon area sort method.
TL;DR: Dibutyryl cyclic AMP (dbcAMP) was found to have no effect on the rate of axonal outgrowth measured by the pinch test, and Histological examination of the pinch-tested nerves showed that the drug had noEffect on the numbers of regenerating silver-stained axons or fluorescent noradrenergic axons seen at various levels distal to the testing lesion.
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TL;DR: The context-sensitive languages cannot be recognized in linear time by deterministic multitape Turing machines, and are strictly contained in the class of languages recognized by Turing machines of tape complexity.
Abstract: It is shown that every deterministic multitape Turing machine of time complexity t(n) can be simulated by a deterministic Turing machine of tape complexity t(n)/logt(n). Consequently, for tape constructable t(n), the class of languages recognizable by multitape Turing machines of time complexity t(n) is strictly contained in the class of languages recognized by Turing machines of tape complexity t(n). In particular the context-sensitive languages cannot be recognized in linear time by deterministic multitape Turing machines.