73 research outputs found

    Wall Compensation for Ultra Wideband Applications

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    Due to their low frequency contents, ultra wideband (UWB) signals have the ability to penetrate walls and obstacles. As the signal propagates through these obstacles, it gets attenuated, slows down, and gets dispersed. This paper demonstrates wall compensation for through-wall imaging, localization and communication receiver design purposes by first characterizing wave propagation through various building materials in the UWB frequency range. Knowledge of the walls obtained from the wall characterization is used to estimate and correct the position accuracy of a target object located behind the walls using three proposed methods namely; constant amplitude and delay (CDL), frequency dependent data (FFD), and data fitting methods (FIT). The obtained results indicated relatively acceptable measure of wall compensation for the three methods. Results from such work provide insight on how to develop algorithms for effective target position estimation in imaging and localization applications. They are also useful for channel modelling and link budget analysis

    Measuring Improvement in Quality of Life in Community-Based Development Projects in Nigeria

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    The lingering problem of poverty prompted many countries to adopt community-based strategies for improving Quality of Life (QoL) of poor communities. Numerous studies have focused on identifying but ignored to establish the contribution of the factors that influence improvement in QoL by community-based projects. This paper measures, using Structural Equation Modelling, the contribution of the factors that influence QoL in a Community-based Poverty Reduction Project (CPRP) in Nigeria. The model revealed that the measured factors contributed only 36% of the reduction in poverty, which implies that there are other “hidden” factors responsible for the improvement in the quality of life.Keywords: Quality of Life, Community-based Projects, Poverty Reduction, Structural Equation ModellingeISSN 2398-4279 © 2018. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. https://doi.org/10.21834/ajqol.v3i11.124

    Role of endothelial Nox2 NADPH oxidase in angiotensin II-induced hypertension and vasomotor dysfunction

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    NADPH oxidase (Nox)-derived reactive oxygen species (ROS) are known to be involved in angiotensin II-induced hypertension and endothelial dysfunction. Several Nox isoforms are expressed in the vessel wall, among which Nox2 is especially abundant in the endothelium. Endothelial Nox2 levels rise during hypertension but little is known about the cell-specific role of endothelial Nox2 in vivo. To address this question, we generated transgenic mice with endothelial-specific overexpression of Nox2 (Tg) and studied the effects on endothelial function and blood pressure. Tg had an about twofold increase in endothelial Nox2 levels which was accompanied by an increase in p22phox levels but no change in levels of other Nox isoforms or endothelial nitric oxide synthase (eNOS). Basal NADPH oxidase activity, endothelial function and blood pressure were unaltered in Tg compared to wild-type littermates. Angiotensin II caused a greater increase in ROS production in Tg compared to wild-type aorta and attenuated acetylcholine-induced vasorelaxation. Both low and high dose chronic angiotensin II infusion increased telemetric ambulatory blood pressure more in Tg compared to wild-type, but with different patterns of BP change and aortic remodeling depending upon the dose of angiotensin II dose. These results indicate that an increase in endothelial Nox2 levels contributes to angiotensin II-induced endothelial dysfunction, vascular remodeling and hypertension

    NADPH oxidases in cardiovascular disease: insights from in vivo models and clinical studies

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    NADPH oxidase family enzymes (or NOXs) are the major sources of reactive oxygen species (ROS) that are implicated in the pathophysiology of many cardiovascular diseases. These enzymes appear to be especially important in the modulation of redox-sensitive signalling pathways that underlie key cellular functions such as growth, differentiation, migration and proliferation. Seven distinct members of the family have been identified of which four (namely NOX1, 2, 4 and 5) may have cardiovascular functions. In this article, we review our current understanding of the roles of NOX enzymes in several common cardiovascular disease states, with a focus on data from genetic studies and clinical data where available

    Endurance performance is influenced by perceptions of pain and temperature: Theory, applications and safety considerations.

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    Models of endurance performance now recognise input from the brain, including an athlete’s ability to cope with various non-pleasurable perceptions during exercise, such as pain and temperature. Exercise training can reduce perceptions of both pain and temperature over time, partly explaining why athletes generally have a higher pain tolerance, despite a similar pain threshold, compared with active controls. Several strategies with varying efficacy may ameliorate the perceptions of pain (e.g. acetaminophen, transcranial direct current stimulation and transcutaneous electrical stimulation) and temperature (e.g. menthol beverages, topical menthol products and other cooling strategies, especially those targeting the head) during exercise to improve athletic performance. This review describes both the theory and practical applications of these interventions in the endurance sport setting, as well as the potentially harmful health consequences of their use

    Sustainability assessment of community-based poverty reduction projects (CPRP) in Nigeria

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    Community-based development projects have become an important mechanism for channeling development assistance that involves beneficiaries in the design, implementation, and management of community development projects towards improving their living standards. Many evaluation studies have reported improvements and successes with the adoption of the community-based development strategy. However, it has been contended that most community-based development projects have sustainability problems after the withdrawal of the funding agencies. This article focuses on assessing the sustainability of a Community-based Poverty Reduction Project (CPRP) in Kebbi state, Nigeria using a framework of monitoring indicators to measure various dimensions of sustainability of the project The findings of the study revealed that while the initiative has recorded huge successes regarding project outputs during the funding period, the project’s outcomes could not be sustained after the withdrawal of the funding agency. Most of the outputs have problems in different dimensions of sustainability. The authors argue that although many factors contribute to the lack of project sustainability, a key factor is careful planning and implementation. The authors recommend that the design and implementation of the CPRP should focus on economic, community and environmental aspects of sustainability
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