Using amplify-and-forward relay for coverage extension in indoor environments

Cooperative communication is a promising method for increasing the capacity and extending the coverage between a base station (BS) and a mobile user (MU) by using relays to exploit cooperative diversity. However, the existing literature mainly focuses on theoretical performance evaluation without experimental validation and, thus, fails to address the effects on real-world radio signal propagation. This research, therefore, aims to develop a prototype amplify-and-forward (AF) relay using software-defined radio (SDR) to evaluate the real-world performance of such a relay in improving coverage. The proposed relay is developed using the LabVIEW software and programmed on a National Instruments-Universal Software Radio Peripheral 2922 (NI-USRP 2922) SDR platform. The major merit of this entire communication setup is less expensive as the system uses a reprogrammable hardware. The measurements are performed indoors, and the signal strength or received power at the MU in cases with and without the relay is recorded. The results show that the received power performance and signal-to-noise ratio (SNR) at the user improve significantly when the AF relay is deployed compared to when direct link point-to-point transmission without the relay is used

Effect of Cu AND Zn On Maize (Zea Mays L.) Yield and Nutrient Uptake in Coastal Plain Sand Derived Soils of Southeastern Nigeria

Micronutrients, which are often found to be lacking in coastal plain sand derived soils, can lead to higher crop yields in this area. The use of Cu and Zn as fertilizers could be a variable option to fulfill the demand for these elements and also to increase its contents in maize grains. In this study, laboratory, greenhouse and field studies were undertaken to investigate the status of Cu and Zn and to find out whether the addition of these nutrient elements would increase maize grain yields and yield components and also, remediate their constraints in coastal plain sand derived soil of southeastern Nigeria, for optimization of maize (Zea mays L.) yields. Dry matter yields, plant concentrations, plant uptake, and maize grain yield was used to evaluate the effects of Cu and Zn levels. In both the greenhouse and field experiments, hydrated Cu and Zn sulphate fertilizers were applied to the soils in separate experiments at seven levels (0, 2, 4, 6, 8, 10 and 12 kg ha-1) for Cu and Zn respectively. A recommended N, P, and K at rates of 120, 60, 30 kg ha-1, respectively, were also used as basal application. The status of available Cu and Zn by 0.1 HCl were found to be low in the soil. The application of Cu and Zn into the soils significantly (P<0.05) increased both maize DM and grain yields. Maximum grain yields and uptake in maize were established at 10 kg Cu ha-1 and 8 kg Zn ha-1, respectively. The estimated optimum rates for Cu and Zn under greenhouse environments were also established at 10 kg Cu ha-1 and 8 kg Zn ha-1, respectively. However, maize response curve showed that for optimum grain yield, concentration for Cu was determined to be 35.9 mg kg-1, while for Zn it was 32.1 mg kg-1. The current study showed that though the soils has a severe Cu and Zn deficiency, which could be due to their strong sorption capacity, and nutrients mining, due to intensive cropping, maize production can still be increased considerably in this soil and other similar soils in the same agroecological zone within a coastal plain sand derived soil by applying Cu and Zn at rates of 10 kg Cu ha-1 and 8 kg Zn ha-1, respectively

Charging management protocol for near field communication charging

The current multiplicity of mobile communication devices has provided an impetus for the research into new mechanisms to supplement battery charge. Wireless charging is a solution that serves to eliminate the cable requirements of typical battery charging implementations. Numerous wireless charging implementations are based on inductive coupling, similar to existing non-radiative short range communication systems. This study proposes incorporating a charge management protocol into the existing Near Field Communication Interface and Protocol-1 (NFCIP-1) specification to achieve NFC-enabled wireless charging. To this end, the original NFCIP-1 protocol has been modified through a time-sharing arrangement to support a charging task within the protocol cycle. Simulations of the modified protocol cycle were implemented using an appropriate battery model and charging algorithm. Numerical results show that the modified protocol is able to charge the target battery with minimum communication overhead. Satisfactory performance is also observed for charging up to 2 target devices in a single session

Prevalence and determinants of use of traditional methods of infertility treatment among women attending infertility clinic in Southeast Nigeria

Infertility, an obstacle to healthy living, makes its victims patronize traditional methods of infertility treatment (TMIT) in spite of associated complications. They turn to hospitals when this method fails. This is actually a serious issue because the presence of contaminated herbal products and the relationship between the use of TMIT and noncompliance with biomedical treatment regimens constitutes a major concern in medical practice. And the use of traditional methods of infertility treatment has been correlated with severe and fatal consequences. Therefore, the study assessed prevalence/determinants of TMIT use among patients visiting the gynaecology clinic at Alex Ekwueme Federal University Teaching Hospital Abakaliki (AE-FUTHA). Descriptive cross-sectional design was adopted for the research. Only 263 women took part in the study. The research instrument was questionnaire. Data were analyzed using descriptive statistics. Findings revealed that 95.4% of these women have used traditional methods for infertility treatment and factors influencing infertile women’s use of TMIT are demographic characteristics, infertility duration, husbands’ relatives’ pressure and cheap cost of traditional medical treatment. Again, inability of infertile women to disclose TMIT use to healthcare providers makes effective treatment difficult. Therefore, these impediments expose infertile women to use TMIT. The result is a guide to healthcare providers who are expected to know the extent of their parents’ use of TMIT

Investigation of Unequal Planar Wireless Electricity Device for Efficient Wireless Power Transfer

This article focuses on the design and investigation of a pair of unequally sized wireless electricity (Witricity) devices that are equipped with integrated planar coil strips. The proposed pair of devices consists of two different square-shaped resonator sizes of 120 mm × 120 mm and 80 mm × 80 mm, acting as a transmitter and receiver, respectively. The devices are designed, simulated and optimized using the CST Microwave Studio software prior to being fabricated and verified using a vector network analyzer (VNA). The surface current results of the coupled devices indicate a good current density at 10 mm to 30 mm distance range. This good current density demonstrates that the coupled devices’ surface has more electric current per unit area, which leads to a good performance up to 30 mm range. Hence, the results also reveal good coupling efficiency between the coupled devices, which is approximately 54.5% at up to a 30 mm distance, with both devices axially aligned. In addition, a coupling efficiency of 50% is achieved when a maximum lateral misalignment (LM) of 10 mm, and a varied angular misalignment (AM) from 0° to 40° are implemented to the proposed device

Semi-transparent frequency reconfigurable antenna with DGS

In this letter, a semi-transparent frequency reconfigurable antenna is proposed and investigated. This antenna is implemented on glass as a substrate, AgHT-4 as a radiating element and copper as its ground plane to result in a semi-transparent feature. A pair of PIN diodes is utilized as microwave switches along with a DC biasing circuit. This proposed antenna is fed by a CPW arrangement and introduces unequal E-shaped Defected Ground Structure (DGS) on the ground plane for modification of the electrical length. The antenna exhibits a −10 dB impedance bandwidth from 3 to 6 GHz when PIN diodes are ON, and a resonance at 4.75 GHz when pin diodes are OFF. The proposed antenna is fabricated to validate its performance in terms of reflection coefficient and radiation pattern

Descriptive epidemiology of cholera outbreak in Nigeria, January-November, 2018: implications for the global roadmap strategy

Background: The cholera outbreak in 2018 in Nigeria reaffirms its public health threat to the country. Evidence on the current epidemiology of cholera required for the design and implementation of appropriate interventions towards attaining the global roadmap strategic goals for cholera elimination however seems lacking. Thus, this study aimed at addressing this gap by describing the epidemiology of the 2018 cholera outbreak in Nigeria. Methods: This was a retrospective analysis of surveillance data collected between January 1st and November 19th, 2018. A cholera case was defined as an individual aged 2 years or older presenting with acute watery diarrhoea and severe dehydration or dying from acute watery diarrhoea. Descriptive analyses were performed and presented with respect to person, time and place using appropriate statistics. Results: There were 43,996 cholera cases and 836 cholera deaths across 20 states in Nigeria during the outbreak period, with an attack rate (AR) of 127.43/100,000 population and a case fatality rate (CFR) of 1.90%. Individuals aged 15 years or older (47.76%) were the most affected age group, but the proportion of affected males and females was about the same (49.00 and 51.00% respectively). The outbreak was characterised by four distinct epidemic waves, with higher number of deaths recorded in the third and fourth waves. States from the north-west and north-east regions of the country recorded the highest ARs while those from the north-central recorded the highest CFRs. Conclusion: The severity and wide-geographical distribution of cholera cases and deaths during the 2018 outbreak are indicative of an elevated burden, which was more notable in the northern region of the country. Overall, the findings reaffirm the strategic role of a multi-sectoral approach in the design and implementation of public health interventions aimed at preventing and controlling cholera in Nigeri

Using and improving the PHISICC paper-based tools in the health facility laboratories: examples of Human Centered Design taking systems thinking into practice, in Côte d'Ivoire and Nigeria

BackgroundHealth workers in low- and middle-income countries are increasingly demanded to collect more and more data to report them to higher levels of the health information system (HIS), in detriment of useful data for clinical and public health decision-making, potentially compromising the quality of their health care provison. In order to support health workers' decision-making, we engaged with partners in Côte d'Ivoire, Mozambique and Nigeria in a research project to conceive, design, produce, implement and test paper-based health information tools: the PHISICC tools. Our aim was to understand the use of PHISICC tools by health workers and to improve them based on their feedback.MethodsThe design Health Facility Laboratories (HF Labs) in Côte d'Ivoire and in Nigeria were set up after months of use of PHISICC tools. Activities were structured in three phases or 'sprints' of co-creative research. We used a transdisciplinary approach, including anthropology and Human Centered Design (HCD), observations, shadowing, structured interviews and co-creation.ResultsHealth workers appreciated the standardization of the tools across different health care areas, with a common visual language that optimized use. Several design issues were raised, in terms of formats and contents. They strongly appreciated how the PHISICC registers guided their clinical decision-making and how it facilitated tallying and counting for monthly reporting. However, adherence to new procedures was not universal. The co-creation sessions resulted in modifications to the PHISICC tools of out-patient care and postnatal care.DiscussionAlthough health systems and systemic thinking allowed the teams to embrace complexity, it was the HCD approach that actually produced a shift in researchers' mind-set: from HIS as data management tools to HIS as quality of care instruments. HCD allowed navigating the complexity of health systems interventions due to its capacity to operate change: it not only allowed us to understand how the PHISICC tools were used but also how to further improve them. In the absence of (or even with) an analytical health systems framework, HCD approaches can work in real-life situations for the ideation, testing and implementation of interventions to improve health systems and health status outcomes

An overview of anti-diabetic plants used in Gabon: Pharmacology and Toxicology

© 2017 Elsevier B.V. All rights reserved.Ethnopharmacological relevance: The management of diabetes mellitus management in African communities, especially in Gabon, is not well established as more than 60% of population rely on traditional treatments as primary healthcare. The aim of this review was to collect and present the scientific evidence for the use of medicinal plants that are in currect by Gabonese traditional healers to manage diabetes or hyperglycaemia based here on the pharmacological and toxicological profiles of plants with anti-diabetic activity. There are presented in order to promote their therapeutic value, ensure a safer use by population and provide some bases for further study on high potential plants reviewed. Materials and methods: Ethnobotanical studies were sourced using databases such as Online Wiley library, Pubmed, Google Scholar, PROTA, books and unpublished data including Ph.D. and Master thesis, African and Asian journals. Keywords including ‘Diabetes’ ‘Gabon’ ‘Toxicity’ ‘Constituents’ ‘hyperglycaemia’ were used. Results: A total of 69 plants currently used in Gabon with potential anti-diabetic activity have been identified in the literature, all of which have been used in in vivo or in vitro studies. Most of the plants have been studied in human or animal models for their ability to reduce blood glucose, stimulate insulin secretion or inhibit carbohydrates enzymes. Active substances have been identified in 12 out of 69 plants outlined in this review, these include Allium cepa and Tabernanthe iboga. Only eight plants have their active substances tested for anti-diabetic activity and are suitables for further investigation. Toxicological data is scarce and is dose-related to the functional parameters of major organs such as kidney and liver. Conclusion: An in-depth understanding on the pharmacology and toxicology of Gabonese anti-diabetic plants is lacking yet there is a great scope for new treatments. With further research, the use of Gabonese anti-diabetic plants is important to ensure the safety of the diabetic patients in Gabon.Peer reviewedFinal Accepted Versio