11,046 research outputs found

    Distributional Considerations in the Overregulation of Health Professionals, Health Facilities, and Health Plans

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    Conover addresses the equity issue in health care spending. Conover concludes that the marginal impact of health regulation is to make the US health system more, rather than less, regressive

    On the neural computation of utility

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    The rewarding effect produced by electrical stimulation of the lateral hypothalamus can compete and summate with gustatory rewards. However, physiological manipulations, such as sodium depletion and the accumulation of an energy-rich solution in the gut, can alter the rewarding impact of the gustatory stimuli without producing substantial changes in the rewarding effect of the electrical stimulation. On the basis of their competition and summation, it is argued that the artificial and natural rewards are evaluated in a common currency, represented in an aggregate firing-rate code. Such a code would make it possible for the synchronous, spatially contiguous pattern of neural firing induced by the electrode to simulate a signal normally produced by asynchronous, spatially distributed activity. It is suggested that a unidimensional code of this sort is employed to represent the utility of a goal object. In order for physiological feedback to alter the utility of one natural reward, such as sucrose, without changing the utility of a second natural reward, such as a salt solution, the physiological feedback signals must enter into the computation of utility at a stage of processing in which the representations of the two natural rewards are distinct. However, orderly choice between such rewards implies that their utilities are expressed ultimately in a common neural currency. That physiological feedback alters the rewarding effects of the gustatory stimuli suggests that the physiological feedback signals modulate the value of such natural stimuli at a stage of processing prior to their translation into a common currency. In contrast, physiological feedback would fail to alter the rewarding effect of the electrical stimulation if the electrically evoked signal is injected at a later stage processing, a stage in which different rewards are represented in a common currency. In this view, the signal injected by the electrical stimulation mimics the utility of a natural stimulus but not its sensory quality

    Preliminary Investigation on the Physiology and Ecology of Luminescence in the Copepod, Metridia lucens

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    1. Skin glands believed to be the source of luminescence were found on the anterior portion of the head, on the last thoracic segment, and on the posterior margins of each segment of the abdomen. 2. The maximum intensity of the luminescent flash was 1.2 x 10-3 µw./cm.2 (at 18 cm.). The flash rose rapidly to peak intensity and then decayed slowly. The total duration of the flashes with peaks greater than 10-4 µw./cm.2 ranged from 3 to 50 seconds. 3. The peak of the luminescence spectrum occcurred at 482 mµ and the curve fell off to one-half the maximum value at 440 mµ and 525 mµ. 4. The ability of Metridia to luminesce on stimulation was found to be largely unaffected by prolonged laboratory culture. Starvation had little effect on the luminescence for the first three weeks and there was never any inhibition by previous light- or dark-adaptation. 5. With an increase in the strength of the electric stimulus from 0.3 amp. to 0.7 amp., the intensity of the luminescent flash was found to increase. With pulses stronger than 0.7 amp. no change in intensity was recorded but the number of successive responses to repeated stimuli was reduced. Duration of the pulse had little effect on the intensity or the number of successive responses. 6. Metridia showed a lag time of 8-10 msc. to the beginning of the luminescent response. The lag time to the peak of the luminescent response varied from 20 to 60 msc. 7. There was no spontaneous luminescence produced by groups of Metridia under conditions of constant darkness. However, the presence of certain planktonic predators, most notably Meganyctiphanes norvegica, caused a brilliant display of luminescence. The number of flashes attributable to Metridia was always greater than the number of Metridia eaten by the predator. There was little evidence that the luminescent euphausiid, Meganyctiphanes, flashed spontaneously either in the presence or absence of its prey. 8. Observations on the behavior of Metridia during and just after luminescence suggest that the flashing may be involved in an escape mechanism, but the precise effect of the light on the predator has not been determined

    Misallocation and Productivity in Colombia’s Manufacturing Industries

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    Following Hsieh and Klenow (2009), this paper studies productivity dispersions in Colombian industrial establishments using the Colombian Annual Manufacturing Survey (AMS) from 1982 to 1998. The United States is used as a benchmark to estimate the reallocation of capital and labor to equalize marginal products across plants in Colombia. Gains are found in manufacturing Total Factor Productivity (TFP) of approximately 3-8 percent and TPF is positively correlated with exporting status, age, size, and location in the central region of the country. There is also suggestive evidence that opening the economy in 1991 is associated with an increase in plant productivity levels for firms that export goods. The 1990 reform that reduced dismissal costs is associated with an increase in productivity, while the reform that increased labor costs in 1993 is associated with a decrease in plants’ productivity. Further work is needed to establish a causal relation between productivity and policy changes.Total Factor Productivity, Industry, Reallocating factors of production, Colombia

    Manipulation of Social Program Eligibility: Detection, Explanations and Consequences for Empirical Research

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    We document manipulation of a targeting system which used a poverty index score to determine eligibility for social welfare programs in Colombia, including health insurance. We show strategic behavior in the timing of the household interviews around local elections, and direct manipulation when some households had their eligibility scores lowered. Initially the number of interviews increased around local elections. After the algorithm was made public to local officials, the score density exhibited a sharp discontinuity exactly at the eligibility threshold. The discontinuity at the threshold is larger where mayoral elections are more competitive; and smaller in municipalities with less competitive elections, more community organizations and higher newspaper circulation.Manipulation, Targeting, Local elections, Colombia

    The Impact of Receiving Price and Climate Information in the Agricultural Sector

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    Previous studies indicate that Colombian farmers make production decisions based on informal sources of information, such as family and neighbors or tradition. In this paper we randomize recipients of price and climate information using text messages (SMS technology). Under this experimental design we find that relative to those farmers who did not receive SMS information, the farmers that did had better knowledge of prices and the dispersion in the expected price of their crops was narrower, although we do not see a significant difference in the actual sale price. Farmers also report that text message information is useful and becomes an important source of information for sales. Even though we find significant reduction in crop loss in general and due to weather conditions, we do not find significant changes in their revenues or householdexpenditures.Randomized evaluation, price and climate information in agriculture, bargaining, spillovers, SMS technology

    Compression and R-wave detection of ECG/VCG data

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    Application of information theory to eliminate redundant part of electrocardiogram or vectorcardiogram is described. Operation of medical equipment to obtain three dimensional study of patient is discussed. Use of fast Fourier transform to accomplish data compression is explained

    JPL's Real-Time Weather Processor project (RWP) metrics and observations at system completion

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    As an integral part of the overall upgraded National Airspace System (NAS), the objective of the Real-Time Weather Processor (RWP) project is to improve the quality of weather information and the timeliness of its dissemination to system users. To accomplish this, an RWP will be installed in each of the Center Weather Service Units (CWSUs), located in 21 of the 23 Air Route Traffic Control Centers (ARTCCs). The RWP System is a prototype system. It is planned that the software will be GFE and that production hardware will be acquired via industry competitive procurement. The ARTCC is a facility established to provide air traffic control service to aircraft operating on Instrument Flight Rules (IFR) flight plans within controlled airspace, principally during the en route phase of the flight. Covered here are requirement metrics, Software Problem Failure Reports (SPFRs), and Ada portability metrics and observations

    Earth science data study

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    The research proposed in this contract concerning investigations of existing and planned Earth Science and Applications Division (ESAD) data management systems and research into utilities for the access and display of scientific data products was completed. A summary of this work is provided
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