4,384 research outputs found

    Schooling, cognitive ability, and health

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    A large literature documents a strong correlation between health and educational outcomes. In this paper we investigate the role of cognitive ability in the healthā€“education nexus. Using NLSY data, we show that cognitive ability accounts for roughly one quarter of the association between schooling and health. Both schooling and ability are strongly associated with health at low levels but less related or unrelated at high levels. Estimates treating schooling as endogenous to health suggest that most of the correlation between schooling and health is attributable to unobserved heterogeneity, except possibly at low levels of schooling for individuals with low cognitive ability. An implication is that policies which increase schooling will only increase health to the extent that they increase the education of poorly-educated individuals; subsidies to college education, for example, are unlikely to increase population health.education, health, intelligence, correlated random coefficient

    Schooling, cognitive ability, and health

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    A large literature documents a strong correlation between health and educational outcomes. In this paper we investigate the role of cognitive ability in the healthā€“education nexus. Using NLSY data, we show that cognitive ability accounts for roughly one quarter of the association between schooling and health. Both schooling and ability are strongly associated with health at low levels but less related or unrelated at high levels. Estimates treating schooling as endogenous to health suggest that most of the correlation between schooling and health is attributable to unobserved heterogeneity, except possibly at low levels of schooling for individuals with low cognitive ability. An implication is that policies which increase schooling will only increase health to the extent that they increase the education of poorly-educated individuals; subsidies to college education, for example, are unlikely to increase population health.education, health, intelligence, correlated random coefficient models

    Minimizing the cost of fault location when testing from a finite state machine

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    If a test does not produce the expected output, the incorrect output may have been caused by an earlier state transfer failure. Ghedamsi and coworkers generate a set of candidates and then produce further tests to locate the failures within this set. We consider a special case where there is a state identification process that is known to be correct. A number of preset and adaptive approaches to fault location are described and the problem of minimizing the cost is explored. Some of the approaches lead to NP-hard optimization problems for which possible heuristics are suggested

    Enhancing Physical Layer Security in AF Relay Assisted Multi-Carrier Wireless Transmission

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    In this paper, we study the physical layer security (PLS) problem in the dual hop orthogonal frequency division multiplexing (OFDM) based wireless communication system. First, we consider a single user single relay system and study a joint power optimization problem at the source and relay subject to individual power constraint at the two nodes. The aim is to maximize the end to end secrecy rate with optimal power allocation over different sub-carriers. Later, we consider a more general multi-user multi-relay scenario. Under high SNR approximation for end to end secrecy rate, an optimization problem is formulated to jointly optimize power allocation at the BS, the relay selection, sub-carrier assignment to users and the power loading at each of the relaying node. The target is to maximize the overall security of the system subject to independent power budget limits at each transmitting node and the OFDMA based exclusive sub-carrier allocation constraints. A joint optimization solution is obtained through duality theory. Dual decomposition allows to exploit convex optimization techniques to find the power loading at the source and relay nodes. Further, an optimization for power loading at relaying nodes along with relay selection and sub carrier assignment for the fixed power allocation at the BS is also studied. Lastly, a sub-optimal scheme that explores joint power allocation at all transmitting nodes for the fixed subcarrier allocation and relay assignment is investigated. Finally, simulation results are presented to validate the performance of the proposed schemes.Comment: 10 pages, 7 figures, accepted in Transactions on Emerging Telecommunications Technologies (ETT), formerly known as European Transactions on Telecommunications (ETT

    Memory fMRI predicts verbal memory decline after anterior temporal lobe resection.

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    To develop a clinically applicable memory functional MRI (fMRI) method of predicting postsurgical memory outcome in individual patients

    Donor notification in reactive donors and their response to communication

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    Background: Blood transfusion is associated with the risk of transmitting transfusion transmissible infections (TTI) even after the thorough mandatory TTI screening of blood units. To prevent disease transmission, it is important to inform, notify and counsel the donors about their seroreactive status at the blood centre. The present study determines the response of various TTI reactive donors for post donation counselling after notification and their persistence in society as reactive donors.Methods: It was a retrospective study conducted at tertiary care center from 1May2015 to 30April2017. Re-active donors were called to the blood bank by telephonic call and letters. Reactive donors on complying at center were retested, counselled and referred to appropriate centre for further management.Results: There were 34,204 blood donations over period of two years, out of which 375[1.09%] were reactive donors. Of these HBV reactive comprises of 166/34204(0.48%), HCV were 40/34204(0.11%), HIV reactive donors comprises of 26/34204(0.07%), Syphilis 138/34204[0.40%] and there were five cases of co-infection, two for HIV+ HCV, two cases HIV+HBV and one case of co-infection with HBV+ Syphilis. A total of 375 TTI reactive donors were identified, out of which (227/375) 60.5% contacted by tele-phone calls and letters and remaining (148/375) 39.46% cannot be contacted. Out of 227 contacted donors only 117 donors reported for post donation counselling i.e. response rate of 51.54%.Conclusions: Donor notification is efficient method of curtailing TTI but undermined by communication failure with donors, resulting in persistent load of blood transmissible infectious risk

    A PACS alternative for transmitting DICOM images in a high latency environment

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    Picture Archiving and Communication System(PACS) is responsible for storing Digital Imaging and Communication in Medicine (DICOM) images fromradiology modalities into its database, images takes a lot of time to transfer to remote location through WAN due to large file size and slow transfer protocol. A PACS alternative system has been developed which performs basic functions of a generic PACS. Images directly from modalities are large in size by default transfer syntax of these images is Endian Explicit syntax. Changing this transfer syntax to lossless JPEG 2000 decreases the file size and because of lossless compression quality of image is still same as original image. These compressed images are then copied into Network Attached Storage working as PACS alternative. A series of test conducted in lab with multiple transfer protocol on Network Attached Storage (NAS) to find out which transfer protocol is faster under moderate speed and high latency network

    Critical considerations of the contribution of the corticomotoneuronal pathway to central fatigue

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    Neural drive originating in higher brain areas reaches exercising limb muscles through the corticospinal-motoneuronal pathway, which links the motor cortex and spinal motoneurones. The properties of this pathway have frequently been observed to change during fatiguing exercise in ways that could influence the development of central fatigue (i.e. the progressive reduction in voluntary muscle activation). However, based on differences in motor cortical and motoneuronal excitability between exercise modalities (e.g. single-joint vs. locomotor exercise), there is no characteristic response that allows for a categorical conclusion about the effect of these changes on functional impairments and performance limitations. Despite the lack of uniformity in findings during fatigue, there is strong evidence for marked ā€˜inhibitionā€™ of motoneurones as a direct result of voluntary drive. Endogenous forms of neuromodulation, such as via serotonin released from neurones, can directly affect motoneuronal output and central fatigue. Exogenous forms of neuromodulation, such as brain stimulation, may achieve a similar effect, although the evidence is weak. Non-invasive transcranial direct current stimulation can cause transient or long-lasting changes in cortical excitability; however, variable results across studies cast doubt on its claimed capacity to enhance performance. Furthermore, with these studies, it is difficult to establish a cause-and-effect relationship between brain responsiveness and exercise performance. This review briefly summarizes changes in the corticomotoneuronal pathway during various types of exercise, and considers the relevance of these changes for the development of central fatigue, as well as the potential of non-invasive brain stimulation to enhance motor cortical excitability, motoneuronal output and, ultimately, exercise performance. (Figure presented.)
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