2,109 research outputs found

    Tools and technologies for expert systems: A human factors perspective

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    It is widely recognized that technologies based on artificial intelligence (AI), especially expert systems, can make significant contributions to the productivity and effectiveness of operations of information and knowledge intensive organizations such as NASA. At the same time, these being relatively new technologies, there is the problem of transfering technology to key personnel of such organizations. The problems of examining the potential of expert systems and of technology transfer is addressed in the context of human factors applications. One of the topics of interest was the investigation of the potential use of expert system building tools, particularly NEXPERT as a technology transfer medium. Two basic conclusions were reached in this regard. First, NEXPERT is an excellent tool for rapid prototyping of experimental expert systems, but not ideal as a delivery vehicle. Therefore, it is not a substitute for general purpose system implementation languages such a LISP or C. This assertion probably holds for nearly all such tools on the market today. Second, an effective technology transfer mechanism is to formulate and implement expert systems for problems which members of the organization in question can relate to. For this purpose, the LIghting EnGineering Expert (LIEGE) was implemented using NEXPERT as the tool for technology transfer and to illustrate the value of expert systems to the activities of the Man-System Division

    Cultural Competence: New Conceptual Insights into its Limits and Potential for Addressing Health Disparities

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    The increasing interest in the role of racism and racialization in health disparities, calls for exploring new paradigms in addressing and eliminating health disparities related to race/ethnicity. Cultural competence is conceptualized as one of the keys ways to address racial/ethnic disparities in public health and healthcare. However, for cultural competence to fulfill this role, it requires a critical understanding of the underlying socio-political and economic processes of power, privilege and institutional racism that create, support and maintain existing health disparities. This paper outlines how the concept of cultural competence can be made more robust, by incorporating concepts such as Public Health Critical Race praxis (PHCR) and cultural humility, to more fully tackle the impact of structural inequities on health disparities

    A critique of recent semi-classical spin-half quantum plasma theories

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    Certain recent semi-classical theories of spin-half quantum plasmas are examined with regard to their internal consistency, physical applicability and relevance to fusion, astrophysical and condensed matter plasmas. It is shown that the derivations and some of the results obtained in these theories are internally inconsistent and contradict well-established principles of quantum and statistical mechanics, especially in their treatment of fermions and spin. Claims of large semi-classical effects of spin magnetic moments that could dominate the plasma dynamics are found to be invalid both for single-particles and collectively. Larmor moments dominate at high temperature while spin moments cancel due to Pauli blocking at low temperatures. Explicit numerical estimates from a variety of plasmas are provided to demonstrate that spin effects are indeed much smaller than many neglected classical effects. The analysis presented suggests that the aforementioned `Spin Quantum Hydrodynamic' theories are not relevant to conventional laboratory or astrophysical plasmas.Comment: 11 pages, To appear in Contributions to Plasma Physics. Minor correction on page 3 to electron spin magnetic momen

    Seasonal variabilities of low-latitude mesospheric winds

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    Seasonal variabilities of low-latitude mesospheric winds

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    International audienceObservations of mesospheric winds over a period of four years with the partial reflection radar at Tirunelveli (8.7°N, 77.8°E), India, are presented in this study. The emphasis is on describing seasonal variabilities in mean zonal and meridional winds in the altitude region 70?98 km. The meridional winds exhibit overall transequatorial flow associated with differential heating in the Northern and Southern Hemispheres. At lower altitudes (70?80 km) the mean zonal winds reveal easterly flow during summer and westerly flow during winter, as expected from a circulation driven by solar forcing. In the higher altitude regime (80?98 km) and at all altitudes during equinox periods, the mean zonal flow is subjected to the semi-annual oscillation (SAO). The interannual variability detected in the occurrence of SAO over Tirunelveli has also been observed in the data sets obtained from the recent UARS satellite mission. Harmonic analysis results over a period of two years indicate the presence of long-period oscillations in the mean zonal wind at specific harmonic periods near 240, 150 and 120 days. Results presented in this study are discussed in the context of current understanding of equatorial wave propagation

    Combined effect of retinoic acid and vascular endothelial growth factor on compensatory lung growth following unilateral pneumonectomy in rats

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    Background: The most common complication of complete or partial pneumonectomy is insufficient oxygenation due to loss of respiratory unit leading to reduced quality of life. Retinoic acid and vascular endothelial growth factors are two important signaling molecules essential during normal lung development and together they could enhance the compensatory lung growth and function following pneumonectomy.Methods: Unilateral pneumonectomy of left lung was performed in male wistar albino rats. Retinoic acid (RA) (0.5 mg/kg), vascular endothelial growth factor (VEGF) 5µg/day and vehicle were administered intraperitoneally for 10 days. Lung weight, lung volume, arterial blood gases (ABG), protein and DNA estimations were performed on the contralateral lung.Results: Rats treated with RA alone and combination of RA and VEGF increased the weight and volume of the compensatory lung as compared to control. Protein and DNA concentrations were also increased in the contralateral lung in rats treated with RA alone and RA with VEGF as compared to control. In arterial blood gas analysis, rats treated with combination of RA and VEGF shows an increase in partial pressure of oxygen and oxygen saturation as compared to control, whereas rats treated with RA alone did not significantly improve the oxygen saturation.Conclusions: Combination of VEGF with RA had accelerated compensatory lung growth in pneumonectomized rats probably by increasing type II pneumocyte proliferation and new blood vessels formation in the lung. There is significant increase in arterial blood gases compared to retinoic acid group possibly by the formation of new blood vessels by VEGF which is essential for improving oxygenation of blood and to improve quality of life

    A report on diversity and distribution of four non-indigenous red algae (Rhodophyceae) along the Tamil Nadu coast, Southeast coast of India

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    108-116The present study was revealed that four Indian invasive seaweeds such as Acanthophora spicefera, Gracilaria salicornia, Kappaphycus alvarezii and Polysiphonia brodiei were recorded along the Tamil Nadu coast with 55 study sites from Palk Bay and Gulf of Mannar regions, Southeast coast of India. Maximum abundance of A. spicefera, G. salicornia, K. alvarezii and P. brodiei were recorded in Hare Island, Thondi coast, Thonithurai coast and Chinna muttam coast respectively. Highest species dominance (0.3) was recorded for G. salicornia during monsoon season and lowest dominance (0.05) was recorded for A. spicefera during post monsoon season. Species richness (D’) varied from 0.69-0.94 with minimum recorded was G. salicornia during monsoon season. Similarly, maximum species richness (D’) was recorded for A. spicefera during post monsoon season. Species diversity (H’) was ranged between 1.70 to 3.19 with the minimum was recorded for G.salicornia during monsoon season whereas maximum was recorded for P. brodiei during post monsoon season. The dendrogram results showed that three major clusters based on the abundance of species in the study sites. Further, the results revealed that Cluster 1 occupied by more species abundance at more stations and followed by Cluster 2 and Cluster 3
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