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Empirical Investigation of Calibration Targets in THz in the Near Field From 550 to 700 GHz
Get PDFThe uncertainty of the standard calibration procedure for radar cross-section (RCS) measurement is studied for different targets measured in the near-field from 550 to 700 GHz. Using common calibration spheres and squat cylinders mounted on a styrofoam pedestal at waterline (zero-degrees elevation), the calibration difference measure is determined for each target. Similarly, the difference metric is determined for square trihedral and tophat targets placed on a ground plane and measured at different elevation angles. The mean calibration measure is calculated using the dual calibration target method and repeated measurements in an anechoic chamber. The specific THz system is described and the results show how the near field scattering behaviors degrade the accuracy of the scattering measurement. Additional analysis shows the measurement uncertainty to be within a few decibels for frequencies within 580 to 650 GHz
A Pade-ENO Flux Reconstruction for High-Speed Flows
Get PDFThe development of high order numerical schemes has been instrumental in advancing computational fluid dynamics (CFD), particularly for applications requiring high resolution of discontinuities and complex flow phenomena prevalent in high-speed flows. This thesis introduces the Pade-ENO scheme, a high-order method that integrates Essentially Non-Oscillatory (ENO) techniques with compact Pade stencils to achieve superior accuracy, up to 7th order, while maintaining stability in harsh environments. The scheme’s performance is evaluated through benchmark tests, including the advection equation, Burgers’ equation, and the Euler equations. For high Mach number flows, such as the sod shock tube the Pade-ENO method demonstrates its ability to resolve sharp gradients and discontinuities with no smoothing required. Numerical results highlight the scheme’s robustness and its potential as a powerful tool for high-speed aerodynamic simulations, paving the way for future advancements in CFD modeling
Internalized HIV Stigma and Viral Suppression: Examining the Mediating and Moderating Roles of Substance Use and Social Support
No full textObjective: The aim of this study was to examine the effects of internalized HIV stigma on viral nonsuppression via depressive symptoms, alcohol use, illicit drug use, and medication adherence and investigate whether social support moderates these effects. Design: Longitudinal observational clinical cohort of patients in HIV care in the US. Methods: Data from the CFAR Network for Integrated Clinical Systems (2016-2019) were used to conduct structural equation models (SEM) to test the indirect effects of internalized HIV stigma on viral nonsuppression through depressive symptoms, illicit drug use, alcohol use, and medication adherence. Moderated mediation with an interaction between social support and internalized HIV stigma was examined. Results: Among 9574 individuals included in the study sample, 81.1% were men and 41.4% were black, non-Hispanic. The model demonstrated good fit (root mean square error of approximation = 0.028; standardized root means square residual = 0.067). The overall indirect effect was significant [b = 0.058; se = 0.020; β = 0.048; 95% confidence interval (95% CI) = 0.019-0.098], indicating that internalized HIV stigma\u27s impact on viral nonsuppression was mediated by depressive symptoms, illicit drug use, and medication adherence. An interaction was observed between internalized HIV stigma and social support on alcohol use; however, there was no moderated mediation for any of the mediators. Conclusion: Internalized HIV stigma indirectly impacts viral nonsuppression through its effects on depressive symptoms, illicit drug use, and medication adherence. Social support may buffer the impact, but more research is needed. Understanding the pathways through which internalized stigma impacts viral suppression is key to improving health of people with HIV
Artificial Intelligence and Family Medicine
No full textArtificial intelligence (AI) is certainly going to have a large, potentially huge, impact on the practice of family medicine. The specialty is fortunate to have leading experts in the field to guide us along the way. One such team of forward thinkers provides insights into where AI can take the specialty. Another article reports on how well AI performed on the American Board of Family Medicine In-Training Examination. In addition to AI, we have 3 articles that investigate the intersection of social needs and the practice of medicine. Four clinical review articles cover nonalcoholic fatty liver disease, headache treatments, single maintenance and reliever therapy for asthma, and the use of cannabis in the setting of chronic pain. The clinical research articles cover point-of-care hemoglobin A1c testing, continuous glucose monitoring, and screening for HIV. Another group of articles examines the profession of family medicine, covering topics ranging from how women family physicians negotiate their first jobs to the words we use to define primary care
Exact Interval Estimation for Three Parameters Subject to False Positive Misclassification
Get PDFBinary data subject to one type of misclassification exist in various fields. It is collected in a double-sampling scheme that includes a gold standard test and a fallible test. The main parameter of interest for this type of data is the positive probability of the gold standard test. Existing intervals are unreliable because the given nominal level is not achieved. In this paper, we construct an exact interval by inverting the E+M score tests and improve it by the general -function method. We find that the total length of the improved interval is shorter than the exact intervals that are also the improved intervals when we apply the -function to several existing approximate intervals, including the score and Bayesian intervals. Therefore, it is recommended for practice. We are also interested in two other parameters: —the difference between the two positive rates for the fallible and gold standard tests—and —the false positive rate for the fallible test. To the best of our knowledge, the research on these two parameters is limited. For , we find that any interval for can be converted to an interval for . So, the interval converted from the aforementioned recommended interval for is recommended for inferring . For , the improved interval by the -function method over the E+M score interval is derived. We use an example to illustrate how the intervals are computed and provide a real data analysis
An Optimal Exact Interval for Risk Difference in 2×2 Contingency Tables With Structural Zeros
No full textIn studies involving infectious diseases or two-step treatment research, the 2x2 contingency table with a structural zero serves as a common framework for data collection. In biomedical studies and related fields, inferring the risk differences through confidence intervals is of significant importance. However, the reliability of approximate intervals based on asymptotic normality is questionable, particularly in small samples. This paper aims to address this limitation by proposing exact intervals for the risk difference, enhancing both reliability and precision. Initially, a novel interval is introduced using the restricted most probable method, which is then optimized via the h-function method to create an optimal exact interval. A comparative analysis is conducted, contrasting this proposed interval with others derived from methods such as the score method, inferential model method, and modified inferential model method. Numerical studies demonstrate the superiority of the proposed interval in terms of both infimum coverage probability and total interval length. Additionally, two illustrative examples are provided to demonstrate the practical application of this interval in real-world scenarios
The Potential Role of TXA in Treating Brain Hemorrhage
Get PDFElijah Bird’s essay provides an excellent review of the existing research and explores the promising possibilities of TXA in the treatment of brain hemorrhages
Desalination as a Source of Freshwater
Get PDFJacob Pensky\u27s article deals with technology we use to make saltwater drinkable. Drought-stricken coastal communities need desalination plants, especially as Earth\u27s climate warms, but they are expensive and energy-intensive. This article describes ways to reduce the environmental and monetary costs
A Review on the Role of Tomatoes in Pakistan\u27s Agricultural Economy: Challenges and Strategies for White Fly (Bemisa Tabaci: Hemiptera) Management
Get PDFThe largest sector of Pakistan\u27s economy is agriculture. Tomatoes, considered both vegetables and fruits, are an essential part of the daily diet for people in the economy class as well as those with limited means, with per capita food consumption of 8.00 kg recorded in Pakistan. Tomatoes are a rich source of essential nutrients such as Vitamin C, A, and Iron, and naturally contain Lycopene, known for its antioxidant properties that can help prevent cancer. In Pakistan, tomato crops yield approximately 40 kg per acre, which is below the world average of 4.00 tons per acre. The Pakistan renowned tomato varieties are Money Maker, Roma, and Riogrande, cultivating in various regions of the country. A review-based study on research articles has concluded that the lack of knowledge among farmers and the absence of proper management contribute to infestations of Bemisa tabaci, leading to decreased tomato crop yields. From an ecological perspective, employing resistance varieties such as Advanta-1211, T-1359, and Lima, in combination with yellow sticky traps, botanicals, and the use of insecticide Methyl benzoate, offers an integrated approach for managing whitefly infestations in tomato crops, forming a comprehensive Tomato White Fly Pest Management Program
Experimental Test of Reforestation with Maesopsis Eminii Engl. and Millettia Drastica Welw. in the Eco-Climatic Conditions of Kinshasa in the Drc
Get PDFThe study focuses on the the experimental test of reforestation with Maesopsis eminii and Millettia drastica in the eco-climatic conditions of Kinshasa, with the aim of assessing the development and growth of the species through germination, and their behaviour in relation to the soil in the conditions of Kinshasa, with a view to proposing advice for responsible afforestation and reforestation. The results show that both species tend to reduce soil acidity. After cultivation, the pHs were 4.49 and 4.69 respectively for soils 1 and 2, compared with 3.98 for soil 0. In addition, Millettia drastica neutralises aluminium in the soil (reducing edaphic toxicity). As Al has a high valency, it prevents the adsorption of other cations, increasing soil toxicity. Millettia drastica is a slow-growing species, while Maesopsis eminii is fast-growing. The combination of Millettia drastica and Maesopsis eminii helps to improve degraded soils