Showing papers by "Columbia University published in 1983"

A Children's Global Assessment Scale (CGAS)

Abstract: • We evaluated the Children's Global Assessment Scale (CGAS), an adaptation of the Global Assessment Scale for adults. Our findings indicate that the CGAS can be a useful measure of overall severity of disturbance. It was found to be reliable between raters and across time. Moreover, it demonstrated both discriminant and concurrent validity. Given these favorable psychometric properties and its relative simplicity, the CGAS is recommended to both clinicians and researchers as a complement to syndrome-specific scales.

Effects of Public Opinion on Policy

Abstract: The responsiveness of government policies to citizens' preferences is a central concern of various normative and empirical theories of democracy. Examining public opinion and policy data for the United States from 1935 to 1979, we find considerable congruence between changes in preferences and in policies, especially for large, stable opinion changes on salient issues. We present evidence that pubic opinion is often a proximate cause of policy, affecting policy more than policy influences opinion. One should be cautious, however, about concluding that democratic responsiveness pervades American politics.

The Third-Person Effect in Communication

Abstract: A person exposed to a persuasive communication in the mass media sees this as having a greater effect on others than on himself or herself. Each individual reasons: “I will not be influenced, but they (the third persons) may well be persuaded.” In some cases, a communication leads to action   

Conjugate coding

Abstract: restrictions on measurement related to the uncertainty principal. Two concrete examples and some general results are given. The uncertainty principle imposes restrictions on the capacity of certain types of communication channels. This paper will show that in compensation for this \"quantum noise\", quantum mechanics allows us novel forms of coding without analogue in communication channels adequately described by classical physics.

Some Tests of the Effectiveness and Functional Attributes of Miles and Snow's Strategic Types

Abstract: The Miles and Snow strategic typology is tested and extended. Based on a sample of businesses in the PIMS data base, the study explores the effectiveness of the strategic types in different environments and the ways in which defenders and prospectors differ in their functional attributes.

A numerically stable dual method for solving strictly convex quadratic programs

Abstract: An efficient and numerically stable dual algorithm for positive definite quadratic programming is described which takes advantage of the fact that the unconstrained minimum of the objective function can be used as a starting point. Its implementation utilizes the Cholesky and QR factorizations and procedures for updating them. The performance of the dual algorithm is compared against that of primal algorithms when used to solve randomly generated test problems and quadratic programs generated in the course of solving nonlinear programming problems by a successive quadratic programming code (the principal motivation for the development of the algorithm). These computational results indicate that the dual algorithm is superior to primal algorithms when a primal feasible point is not readily available. The algorithm is also compared theoretically to the modified-simplex type dual methods of Lemke and Van de Panne and Whinston and it is illustrated by a numerical example.

Cuff-tear arthropathy.

Abstract: In this report we describe the clinical and pathological findings of cuff-tear arthropathy in twenty-six patients and discuss the differential diagnosis and a hypothesis on the pathomechanics that lead to its development. This lesion is thought to be peculiar to the glenohumeral joint because of the unique anatomy of the rotator cuff. Following a massive tear of the rotator cuff there is inactivity and disuse of the shoulder, leaking of the synovial fluid, and instability of the humeral head. These events in turn result in both nutritional and mechanical factors that cause atrophy of the glenohumeral articular cartilage and osteoporosis of the subchondral bone of the humeral head. A massive tear also allows the humeral head to be displaced upward, causing subacromial impingement that in time erodes the anterior portion of the acromion and the acromioclavicular joint. Eventually the soft, atrophic head collapses, producing the complete syndrome of cuff-tear arthropathy. The incongruous head may eventually erode the glenoid so deeply that the coracoid becomes eroded as well. Although treatment of cuff-tear arthropathy is extremely difficult, the preferred method appears to be a resurfacing total shoulder replacement with rotator-cuff reconstruction and special rehabilitation. We think that it is important to recognize cuff-tear arthropathy as a distinct pathological entity, as such recognition enhances our understanding of the more common impingement lesions. Cuff-tear arthropathy is especially difficult to treat, and although many tears of the rotator cuff do not enlarge sufficiently to allow this condition to develop, it is a factor to consider when deciding whether or not a documented tear of the rotator cuff should be surgically repaired.

The role of cognitive engagement in classroom learning and motivation

Abstract: The article analyzes the concept of student cognitive engagement, and the manner in which classroom instruction may develop self‐regulated learners. Since theory and research on academic motivation, to date only vaguely define the role of learning processes, and since studies of learning strategies rarely assess motivational outcomes, our analysis integrates these two streams of literature. We also identify specific features of instruction and discuss how they might influence the complex of student interpretive processes focal to classroom learning and motivation. Measurement issues and research strategies peculiar to the investigation of cognitive engagement are addressed.

High Profit Strategies in Mature Capital Goods Industries: A Contingency Approach

Abstract: High profit and low profit strategic “gestalts” in two different types of mature capital goods industries are examined. Multiple avenues to high profits are found within both types, but they differ...

Biomechanical considerations in osseointegrated prostheses.

Abstract: On the basis of the previous discussions, several conclusions may be drawn. 1. The close apposition of bone to the titanium implant is the essential feature that allows a transmission of stress from the implant to the bone without any appreciable relative motion or abrasion. The absence of any intermediate fibrotic layer allows stress to be transmitted without any progressive change in the bond or contact between the bone and implant. 2. The use of a threaded screw provides a form of interlocking with the bone on a macroscopic scale that allows full development of the strength of the bone in shear or compression. A smooth, cylindrical implant may require an adhesive bond for satisfactory performance, but a screw shape is able to work as long as the apposition of bone and implant is close, whether or not a true adhesive bond is developed. 3. The distribution of a vertical or lateral load applied to a fixed partial denture depends on the number, arrangement, and stiffness of abutment fixtures used, as well as the form and stiffness of the fixed prosthesis itself. In general a stiff fixed partial denture will distribute loads to several fixtures more effectively. A flexible prosthesis may be adequate if the strength developed by each fixture is able to carry the full load that is applied. Cantilevered ends of a fixed partial denture increases the loading on the first screw nearest the cantilevered end. Moderate overhangs may be tolerated if the fixtures are sufficiently strong. 4. A tight connection of the fixed partial denture to fixtures provides a combined structure that can act in concert with the bone to provide a greater strength than that of the fixture or the jaw bone alone. 5. The osseointegrated implant provides a direct contact with bone and therefore will transmit any stress waves or shocks applied to the fixtures. For this reason it is advisable to use a shock-absorbing material such as acrylic resin in the form of acrylic resin artificial teeth in the fixed partial denture. This arrangement allows for the development of a stiff and strong substructure with adequate shock protection on its outer surface.

Continuity and Transformation in the World Polity: Toward a Neorealist Synthesis

Abstract: Kenneth Waltz's recent book, Theory of International Politics, is one of the most important contributions to international relations theory since his Man, the State and War. It picks up where the earlier work left off: with the structure of the international system serving as the basis for explaining a variety of international outcomes. The most profound and perhaps the most perplexing outcome Waltz attempts to explain is the lack of fundamental change in the international polity. The author argues that Waltz does not fully succeed in this endeavor for three reasons. First, his definition of structure fails to capture so momentous a change as that from the medieval to the modern international systems. Second, his application of the structuralist method leads him to ask questions in such a way that the answers systematically understate the degree of potential change in the contemporary international system. Third, his model of structural explanation turns out to allow only for a reproductive logic but not for a transformational logic. With the epistemological underpinnings of his theory thus biased against the possibility of change, it is not surprising that Waltz finds the likelihood of future continuity compelling. In the spirit of constructive criticism, this review article tries to amend and augment the theory in a manner that is not incompatible with its basic realist precepts.

African monsoons, an immediate climate response to orbital insolation

Abstract: The Croll–Milankovitch astronomical theory of climate1–3 has received strong support from the evidence of a linear climatic forcing by obliquity and precession, although nonlinearity had to be assumed for eccentricity4,5. Moreover, interglacials have appeared to be controlled by the orbital insolation6 although a phase shift of 6,000–5,000 yr is seen between an astronomical climate index and terrestrial climate indicators, dominated by the northern ice-sheet dynamics. Climate proxy data of low latitudes are less directly dependent on the ice sheets. Here it is shown that during the past 464,000 yr, African monsoons signalled by the East Mediterranean sapropels were heaviest always and only when a northern summer monsoon index, computed from the orbital variation of insolation, reached maximum values. This occurred during all the interglacials, but also twice during glacial periods. Thus tropical aridity is not the single climatic pattern of glacial periods. An immediate terrestrial climate response to orbital variations of insolation is established.

A cellular mechanism of classical conditioning in Aplysia: activity-dependent amplification of presynaptic facilitation.

Abstract: A training procedure analogous to differential classical conditioning produces differential facilitation of excitatory postsynaptic potentials (EPSP's) in the neuronal circuit for the siphon withdrawal reflex in Aplysia. Thus, tail shock (the unconditioned stimulus) produces greater facilitation of the monosynaptic EPSP from a siphon sensory neuron to a siphon motor neuron if the shock is preceded by spike activity in the sensory neuron than if the shock and spike activity occur in a specifically unpaired pattern or if the shock occurs alone. Further experiments indicate that this activity-dependent amplification of facilitation is presynaptic in origin and involves a differential increase in spike duration and thus in Ca2+ influx in paired versus unpaired sensory neurons. The results of these cellular experiments are quantitatively similar to the results of behavioral experiments with the same protocol and parameters, suggesting that activity-dependent amplification of presynaptic facilitation may make a significant contribution to classical conditioning of the withdrawal reflex.

Protein-free culture medium

Abstract: A trace element mixture suitable for use in a protein-free tissue culture medium, which comprises water-soluble compounds selected from acids, bases, and salts containing copper, iron, zinc, manganese, silicon, molybdenum, vanadium, nickel, tin, aluminum, silver, barium, bromine, cadmium, cobalt, chromium, fluorine, germanium, iodine, rubidium, zirconium, or selenium, the compounds being devoid of any additional metals other than those present as positive ions selected from groups IA and IIA of the periodic table of elements, wherein the compounds produce a solution containing specified minimum concentrations of the listed elements when dissolved in an amount of water sufficient to produce a concentration for one of the elements equal to the corresponding minimum concentration of the one element while maintaining each remaining element at a concentration equal to or greater than the minimum concentration for the remaining element is disclosed along with cell culture media containing these trace elements and methods of culturing cells using these media.

The Separation of Madagascar and Africa

Abstract: Identification of a sequence of east-west trending magnetic anomalies of Mesozoic age in the western Somali Basin helps define the position of Madagascar in the Gondwana reconstruction. The anomalies are symmetric about ancient ridge segments and are flanked to the north and south by the Jurassic magnetic quiet zone. The motion of Madagascar relative to Africa was from the north and began in the middle Jurassic, about the same time as the initial breakup of Gondwanaland. Sea-floor spreading ceased when Madagascar assumed its present position in the Early Cretaceous.

Morphological Basis of Long-Term Habituation and Sensitization in Aplysia

Abstract: The morphological basis of the persistent synaptic plasticity that underlies long-term habituation and sensitization of the gill withdrawal reflex in Aplysia californica was explored by examining the fine structure of sensory neuron presynaptic terminals (the critical site of plasticity for the short-term forms of both types of learning) in control animals and in animals whose behavior had been modified by training. The number, size, and vesicle complement of sensory neuron active zones were larger in animals showing long-term sensitization than in control animals and smaller in animals showing long-term habituation. These changes are likely to represent an anatomical substrate for the memory consolidation of these tasks.

Turnaround Strategies for Mature Industrial-Product Business Units

Abstract: A study of short-term turnaround attempts by mature industrial-product business units found that efficiency-oriented moves, but not entrepreneurial initiatives, were associated with successful turn...

The interface zone of inorganic implants in vivo: Titanium implants in bone.

Abstract: The interface zone between titanium implants and bone is considered at the macroscopic, microscopic, and molecular levels. A high rate of successful dental implants of pure titanium is associated with a very close apposition of the bone to the titanium surface, called osseointegration. At the macroscopic level, osseointegration allows efficient stress transfer from the implant to the bone without abrasion or progressive movement that can take place if a fibrous layer intervenes. At the microscopic level, surface roughness and porosity provide interlocking of the implant and bone tissue which grows into direct contact with titanium. Sections studied in the electron microscope show that calcified tissue can be identified within 50 A of the implant surface. The interface zone includes a tightly adherent titanium oxide layer on the surface of the implant which may be similar to a ceramic material in relation to tissue response. The five year success rate of 90% in 2895 implants in clinical trials since 1965 is associated with the favorable behavior of bone tissue at the interface zone with pure titanium.

The Second Homology Group of the Mapping Class Group of an Orientable Surface

Abstract: In I-7] Mumford shows that the Picard group P ic (~ ' ) is isomorphic to H2(F; 2~) and conjectures the latter is rank one, g>3 . We prove this below for g>5 . Another interpretation of this theorem may be obtained by identifying H2(F) as bordism classes of fiber bundles F---*W4---* T where T is a closed oriented surface (Sect. 0). When F is closed every such bundle is bordant to F ~ W' --* T', a bundle admitting a section s: T ' ~ W'. The theorem then says that

Research Methodologies for Contingency Approaches to Business Strategy

Abstract: A multisite, multisource research methodology is suggested for students of corporate strategy in order to attain generalizability and statistical significance in reporting findings while not losing the nuances and understanding of each firm's environmental context. A way of incorporating testable hypotheses into sampling designs is suggested and elements of the methodology are illustrated using extant strategy research publications.

The Development of Children’s Knowledge of Self-Control Strategies

Abstract: The study of “metacognition” has become vigorous in recent years, with extensive research exploring the development of children’s knowledge of effective strategies in attention, comprehension, and memory (e.g., Brown, 1980; Flavell & Wellman, 1977). In contrast, the child’s developing understanding of essential strategies for self-regulation — a core aspect of human functioning, basic to virtually all conceptions of personality — has been neglected. Perhaps this neglect reflects the fact that until recently there were few objective criteria against which one could assess the relative efficacy of various strategies for self-control. Studies of the conditions that enhance or impede successful delay of gratification in children (e.g., Miller & Karniol, 1976a, 1976b; Mischel, 1974, 1981b; Toner, 1981; Toner & Smith, 1977; Yates, Lippett, & Yates, 1981) now provide a basis for assessing the child’s developing understanding against objective criteria of efficacy.