27,285 research outputs found

    Further thoughts on precision

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    Background: There has been much discussion amongst automated software defect prediction researchers regarding use of the precision and false positive rate classifier performance metrics. Aim: To demonstrate and explain why failing to report precision when using data with highly imbalanced class distributions may provide an overly optimistic view of classifier performance. Method: Well documented examples of how dependent class distribution affects the suitability of performance measures. Conclusions: When using data where the minority class represents less than around 5 to 10 percent of data points in total, failing to report precision may be a critical mistake. Furthermore, deriving the precision values omitted from studies can reveal valuable insight into true classifier performancePeer reviewedFinal Accepted Versio

    X-Ray Measurement and Porosity in Graphite/Polyimide Composites

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    One of the persistent problems in the control of quality in materials used in structures is that of porosity. Whether the material is a casting, an epoxy composite, or a complex ceramic or metal matrix composite, the presence of porosity, depending upon the severity, causes a degradation of the parts performance characteristics and their longevity. The detection of porosity in many industries is important in two ways, namely, in material quality control and in monitoring process control (1). One class of materials where both of these problems arise is the graphite composites (2–4). To date, the inspection of these composites using an X-ray method has been unsatisfactory in that the film methods frequently tried did not have the sensitivity resolution to yield a quantitative measure of the porosity volume percent. Such a measure becomes even more critical in ceramic composites in that the difference between a good material and a poor one is a level of porosity rather than the presence of porosity, as is the case in graphite epoxy composites. We wish to report results of an X-ray method to measure porosity in materials using the graphite polyimide composites as an example. The method is certainly not restricted to this type of graphite composite or indeed to graphite composites

    Profiling and study of interfacial tension laden with crude lipid extract plant based as surfactant for food application

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    Crude lipid extract plant based namely SPLIP and PULIP are being introduced in this research as a potential surfactant with phospholipid and glycolipid components which playing an important role at the oil/water interface. Since the interaction between the components give a significant impact on the interfaces, the aim of this research is to investigated whether these components in crude plant extract can also interact at oil/water interface compared to commercially available surfactant namely LEC. This work has been carried out with interfacial tension using PAT1. Prior to the interfacial tension analysis, profiling of the crude lipid extract was done using TLC. Finding obtained from TLC indicated that both crude lipid extract spotted phospholipid and glycolipidcomponents. For interfacial results, the interaction between phospholipid and glycolipid in both SPLIP and PULIP give impact at the interfaces; being more surface active results in lower interfacial tension value.Keywords: SPLIP, PULIP, phospholipid, glycolipid, interfacial tensio

    Immunosuppression for liver transplantation in HCV-infected patients: Mechanism-based principles

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    We retrospectively analyzed 42 hepatitis C virus (HCV)-infected patients who underwent cadaveric liver transplantation under two strategies of immunosuppression: (1) daily tacrolimus (TAC) throughout and an initial cycle of high-dose prednisone (PRED) with subsequent gradual steroid weaning, or (2) intraoperative antithymocyte globulin (ATG) and daily TAC that was later space weaned. After 36 ± 4 months, patient and graft survival in the first group was 18/19 (94.7%) with no examples of clinically serious HCV recurrence. In the second group, the three-year patient survival was 12/23 (52%), and graft survival was 9/23 (39%); accelerated recurrent hepatitis was the principal cause of the poor results. The data were interpreted in the context of a recently proposed immunologic paradigm that is equally applicable to transplantation and viral immunity. In the framework of this paradigm, the disparate hepatitis outcomes reflected different equilibria reached under the two immunosuppression regimens between the relative kinetics of viral distribution (systemically and in the liver) and the slowly recovering HCV-specific T-cell response. As a corollary, the aims of treatment of the HCV-infected liver recipients should be to predict, monitor, and equilibrate beneficial balances between virus distribution and the absence of an immunopathologic antiviral T-cell response. In this view, favorable equilibria were accomplished in the nonweaned group of patients but not in the weaned group. In conclusion, since the anti-HCV response is unleashed when immunosuppression is weaned, treatment protocols that minimize disease recurrence in HCV-infected allograft recipients must balance the desire to reduce immunosuppression or induce allotolerance with the need to prevent antiviral immunopathology. Copyright © 2005 by the American Association for the Study of Liver Diseases

    Exploring Consumer and Patient Knowledge, Behavior, and Attitude Toward Medicinal and Lifestyle Products Purchased From the Internet: A Web-Based Survey.

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    BACKGROUND: In recent years, lifestyle products have emerged to help improve people's physical and mental performance. The Internet plays a major role in the spread of these products. However, the literature has reported issues regarding the authenticity of medicines purchased from the Internet and the impact of counterfeit medicines on public health. Little or no data are available on the authenticity of lifestyle products and actual toxicity associated with their use and misuse. OBJECTIVE: Our aim was to investigate consumer and patient attitudes toward the purchase of lifestyle products from the Internet, their knowledge of product authenticity and toxicity, and their experiences with counterfeit lifestyle products. METHODS: A Web-based study was performed between May 2014 and May 2015. Uniform collection of data was performed through an anonymous online questionnaire. Participants were invited worldwide via email, social media, or personal communication to complete the online questionnaire. A total of 320 participants completed the questionnaire. RESULTS: The results of the questionnaire showed that 208 (65.0%) participants purchased lifestyle products from the Internet mainly due to convenience and reduced cost. More than half (55.6%, 178/320) of participants purchased cosmetic products, whereas only a minority purchased medicinal products. Yet, 62.8% (201/320) of participants were aware of the presence of counterfeit lifestyle products from the Internet, and 11.9% (38/320) experienced counterfeit products. In only 0.9% (3/320) of those cases were counterfeit lifestyle products reported to authorities. Moreover, 7.2% (23/320) of the participants experienced adverse effects due to counterfeit lifestyle products. CONCLUSIONS: In summary, patients experienced counterfeit lifestyle products that resulted in adverse effects on their health. Although certain adverse effects were reported in this study, counterfeit products were underreported to authorities. Further public awareness campaigns and patient education are needed

    A new class of sum rules for products of Bessel functions

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    In this paper we derive a new class of sum rules for products of the Bessel functions of first kind. Using standard algebraic manipulations we extend some of the well known properties of JnJ_n. Some physical applications of the results are also discussed. A comparison with the Newberger[J. Math. Phys. \textbf{23} (1982) 1278] sum rules is performed on a typical example.Comment: Published in Journal of Mathematical Physics, 9 pages, no picture

    A Numerical Analysis of Electromagnetic Scattering from Two-Dimensional Edge Terminations

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    Several techniques that influence the low frequency scattering from penetrable edge terminations are evaluated using a hybrid finite element and boundary element method code. The edge terminations consist of a dielectric skin forming an exterior shape with an internal conducting bulkhead. Some of the techniques considered are bulkhead shaping, internal material loading, placement of resistive cards, and the placement of lossy dielectric material rods. The intent of the various treatments is to find a combination or combinations that influence(s) the backscattered field to acceptable levels over a range of frequencies for both transverse magnetic and transverse electric polarizations
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