2,971 research outputs found
On The Non-linear Distortion Effects in an OFDM-RoF Link
Radio over Fiber (RoF) system is a promising technique for microcell and picocell applications for deployment of future ubiquitous wireless data networks. However, the performance of RoF systems can be severely degraded due to non-linear effects in the channel. Also, Orthogonal Frequency Division Multiplexing (OFDM), as a standard for broadband wireless networks, is being proposed for deployment with RoF systems to facilitate the total performance of a system. In this research, at first, the performance of OFDM-based RoF link with Mach-Zehnder modulator distortion effects has been analyzed at 5.8 GHz. Evaluation of mean-squared error of the proposed OFDM-RoF system was carried out to compare with the conventional single carrier system based RoF link after the modulator distortion case and also for fixed Signal to Noise Ratio (SNR) of 20 dB using undistorted OFDM signal. Later, nominal and offset biasing pre-distortion techniques are applied in proposed system to linearize the OFDM-RoF link. Thus, finally a comparison between the aforementioned pre-distortion techniques applied showed important observation in terms of distortion-free dynamic range and SNR to choose offset pre-distortion technique for our proposed system
Financial Development and International Trade inside Asia
This study attempts to document the impact of "Financial development" on international trade between selected Asian economies and rest of the Asian region. Financial development index is used to represent financial development level which includes four dimensions from two perspectives; institutional and market. An "overall financial development index" is calculated by combining institutional and market level financial development indices. Effect of market and institutional dimension is measured separately on international trade of Asian economies with rest of the Asia. Different macro-variables are controlled including GDP per capita, total population, Inward FDI flow, Outward FDI flow and real effective exchange rates for modeling. Sample includes data for twenty years ranging from 1997-2016 for 16 large economies of Asia. Panel data modeling technique "fixed effects regression" is used with two different proxies of dependent variable. "Overall financial development" is found to have positive and significant relationship with international trade. Study confirms the robustness of the results to different measures of international trade. Results from fixed effects model confirm positive and significant relationship between all components of financial development and international trade, and between overall financial development and international trade in Asian economies. Singapore, Japan and South Korea represent highest levels of financial development while other countries showed relatively less development financial development level according to measure used in this study. An important policy implication is if a country wants to grow economically by using instrument of trade policy especially exports improvement, then it has to develop its financial system to efficiently fulfill "international trade finance" needs. Keywords: Financial Development Index, International Trade, Asia DOI: 10.7176/EJBM/11-11-04 Publication date: April 30th 201
Lifestyle Intervention’s Effect and Predictive Value on Weight Loss for University Employees
Obesity is a costly and pervasive risk factor that requires attention to reduce chronic disease rates. This study evaluated the effect of a lifestyle medicine intervention, Complete Health Improvement Program (CHIP), on reducing weight, blood pressure, lipid levels, and hemoglobin A1c. A secondary aim was to build a preliminary predictive model for computing new participants’ potential weight change from CHIP. We evaluated pre- and post-intervention biometric data of 68 individuals who completed a 10-week CHIP intervention at a Midwestern university clinic. Significant reductions (p \u3c 0.05) were observed in weight, diastolic blood pressure, total cholesterol, low-density lipoprotein, and A1c. Regression analyses indicated that the best linear model for predicting change in weight was a one-predictor model with systolic blood pressure. The CHIP intervention effectively promoted weight loss and meaningful reductions in chronic disease risk factors. Larger samples are needed for future regression analyses to create a more robust linear model
Prediction of Advanced Fibrosis in Nonalcoholic Fatty Liver Disease: An Enhanced Model of BARD Score.
UNLABELLED: BACKGROUNDAIMS: The BARD score is a model to detect advanced liver fibrosis in nonalcoholic fatty liver disease (NAFLD) patients. The aims of this study were to identify additional factors and then to build an enhanced version of the BARD score.
METHODS: One hundred seven patients with biopsy-proven NAFLD were enrolled retrospectively. Logistic regressions were performed to identify independent risk factors for advanced liver fibrosis (stage 3 or 4). An enhanced model of the BARD score (BARDI score) was built and evaluated with a receiver operating characteristic (ROC) curve.
RESULTS: In multivariate analysis, age (odds ratio [OR], 0.89; p=0.04), aspartate aminotransferase/alanine aminotransferase ratio (OR, 1.73; p
CONCLUSIONS: The BARDI score had an improved PPV over the BARD score and maintained an excellent NPV. Further study is warranted for its external validation and comparison with other models
Scientometric Review and Thematic Areas for the Research Trends on Marine Hoses
For over three (3) decades, there has been an increase in research on energy sources from the production of oil using flexible marine risers, such as marine hoses. Marine hoses are conduits for special use as rubberized structures with hybrid polymer composites for offshore platforms in the oil and gas industry. This scientometric study uses qualitative, quantitative, and computational approaches. Data were retrieved using a research methodology that was created for this study using the SCOPUS and Web of Science (WoS) databases. This study provides a bibliometric literature review on marine hoses with an emphasis on the advancements made in the field from recent developments, geographical activity by countries, authorship histories, partnerships, funding sources, affiliations, co-occurrences, and potential research areas. The study found that the USA had the most publications, but there were fewer co-occurrences with connections outside the cluster. Due to the difficulty of adaptation, acceptability, qualification, and deployment of marine hoses in the offshore marine industry, this topic contains more conference papers than journal papers. Therefore, more funding sources and collaborations on marine hoses are required to advance the research. This study makes a contribution to scholarship on advances made in petroleum exploration and production for (un)loading hoses
Clinical monitoring of tooth wear progression in patients over a period of one year using CAD/CAM
Purpose: The aim of this study was to clinically monitor the progression of tooth wear over a period of 1 year in a cohort of referred tooth wear patients through the use of a computer-aided design/ computer-assisted manufacture (CAD/CAM) scanner and a standardized scanning/assessment methodology. Materials and Methods: Polyether impressions were made of 11 participants (130 teeth) at baseline and at 1 year. Impressions were poured in type IV dental stone and the anterior teeth were 3D scanned. A surface-matching software was used to compare 1-year and baseline scans and identify any dimensional differences. Results: Parafunctional habits were reported by all patients. All participants exhibited tooth wear ≥ 140 μm in depth and extending to ≥ 280 μm in at least one tooth. Maxillary central incisors were the most commonly and severely affected teeth. Conclusion: The ability of the developed CAD/CAM scanning methodology in clinical monitoring of tooth wear was demonstrated. Further research is needed to assess its practicality in large-scale epidemiologic tooth wear studies
The inflammation, vascular repair and injury responses to exercise in fit males with and without Type 1 diabetes: an observational study.
Type 1 diabetes is associated with raised inflammation, impaired endothelial progenitor cell mobilisation and increased markers of vascular injury. Both acute and chronic exercise is known to influence these markers in non-diabetic controls, but limited data exists in Type 1 diabetes. We assessed inflammation, vascular repair and injury at rest and after exercise in physically-fit males with and without Type 1 diabetes.Ten well-controlled type 1 diabetes (27 ± 2 years; BMI 24 ± 0.7 kg.m(2); HbA1c 53.3 ± 2.4 mmol/mol) and nine non-diabetic control males (27 ± 1 years; BMI 23 ± 0.8 kg.m(2)) matched for age, BMI and fitness completed 45-min of running. Venous blood samples were collected 60-min before and 60-min after exercise, and again on the following morning. Blood samples were processed for TNF-α using ELISA, and circulating endothelial progenitor cells (cEPCs; CD45(dim)CD34(+)VEGFR2(+)) and endothelial cells (cECs; CD45(dim)CD133(-)CD34(+)CD144(+)) counts using flow-cytometry.TNF-α concentrations were 4-fold higher at all-time points in Type 1 diabetes, when compared with control (P 0.05). Within the Type 1 diabetes group, the delta change in cEPCS from rest to the following morning was related to HbA1c (r = -0.65, P = 0.021) and TNF-α (r = -0.766, P = 0.005).Resting cEPCs and cECs in Type 1 diabetes patients with excellent HbA1c and high physical-fitness are comparable to healthy controls, despite eliciting 4-fold greater TNF-α. Furthermore, Type 1 diabetes patients appear to have a blunted post-exercise cEPCs response (vascular repair), whilst a biomarker of vascular injury (cECs) remained comparable to healthy controls
Evidence of Rickettsia and Orientia Infections Among Abattoir Workers in Djibouti.
Of 49 workers at a Djiboutian abattoir, eight (16%, 95% confidence interval [CI]: 9-29) were seropositive against spotted fever group rickettsiae (SFGR), two (4%, 95% CI: 1-14) against typhus group rickettsiae, and three (6%, 95% CI: 2-17) against orientiae. One worker (9%, 95% CI: 2-38) seroconverted against orientiae during the study period. This is the first evidence of orientiae exposure in the Horn of Africa. SFGR were also identified by polymerase chain reaction in 32 of 189 (11%, 95% CI: 8-15) tick pools from 26 of 72 (36%) cattle. Twenty-five (8%, 95% CI: 6-12) tick pools were positive for Rickettsia africae, the causative agent of African tick-bite fever. Health-care providers in Djibouti should be aware of the possibility of rickettsiae infections among patients, although further research is needed to determine the impact of these infections in the country
Holistic User eXperience in Mobile Augmented Reality Using User eXperience Measurement Index
© 2019 IEEE. User eXperience (UX) evaluation in the field of Mobile Augmented Reality (MAR) is a challenging task, which requires the application of many heterogeneous methods, producing a variety of raw signals and subjective data. This multi-method approach is essential for capturing the holistic UX of any product, service or system. In order to convert this data into information and subsequently knowledge, a comprehensive and scalable system is required which can not only quantify the individual UX metrics but also produce a concise result, which is interpretable by anyone. We call this result, the User Experience Measurement Index, and in this paper we present the results of adopting the mixed method UX evaluation approach for evaluating a prototype MAR application using various methods and sensors, applied before, during, and after its usage. Additionally, we present the methodology and results for calculating the UXMI
Bioactive Cembranoids from the Soft Coral Sinularia crassa
Eight new cembranoids, crassarines A–H (1–8) were isolated from the Formosan soft coral Sinularia crassa. Compounds 1–3 represent the rare cembranoids with a 1,12-oxa-bridged tetrahydrofuran ring, while 4 and 5 are the firstly discovered 1,11-oxa-bridged tetrahydropyranocembranoids. The absolute configuration of 6 was determined using the Mosher’s method. Compounds 6 and 8 were found to significantly inhibit the expression of both pro-inflammatory iNOS and COX-2 proteins at 10 μM, respectively, while compounds 4–8 were found to be non-cytotoxic toward the selected human liver cancer cells
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