Estimating the Returns to Schooling: A Comparison of Fixed Effects and Selection Effects Models for Twins

Strong empirical links exist between the number of years spent schooling and earnings. How­ever, the relationship may be masked due to the effect of unobserved factors that influence both wages and schooling. Two of the main econometric models, namely fixed-effects and se­lection-effects, used to analyse returns to schooling were compared using monozygotic and di­zygotic twins’ datasets in Ghana. The efficiency of the models was assessed based on the stan­dard errors associated with the return to schooling estimates. Goodness of fit measures was used as a basis for comparison of the performance of the two models. The results revealed that based on their standard errors, the regression estimates from the selection effects model (MZ = 0.1014±0.0197; DZ = 0.0947±0.0095) were more efficient than the regression estimates from the fixed-effects model (MZ = 0.1115±0.0353; DZ = 0.082±0.0127). However, the AICc values of the fixed effects model (MZAICc = 57.8 and DZAICc = 105.4) were smaller than the AICc values of the selection effects model (MZAICc = 151.6 and DZAICc = 221.6). Findings from the study indicate that, although both models produced consistent estimates of the economic returns to schooling, the fixed effects model provided a better fit to the twins’ data set

Impacts of Urban Sprawl on Livelihoods and Ecology in Peri-Urban Fringe of the Greater Accra Metropolitan Area

The rapid increase in population and urbanization continue to exert growing pressure on resources in most cities. Accra, the capital city of Ghana, has been attracting migrants from all over the country resulting in escalating congestion and housing shortage in the inner cities. The resultant effect of these phenomena is the sprawl of human settlements to peri-urban areas. As a result natural reserves and farmlands are being converted into residentialand non-residential developments in the urban fringes. This study assesses the impact of this trend on livelihoods sustainability and the ecology in the peri-urban areas of Greater Accra Metropolitan Area (GAMA). The study employed primary and secondary sources of data and used stratified sampling in the selection of major road corridors where sprawling was pronounced and intensive. A multi-temporal set of Remote Sensing data was usedto classify Landsat images of GAMA for the years 1986, 1991, 2008 and 2016 to know the extent of land use and land cover change. Environment for Visualizing Image 5.1 was used to process, analyse and integrate the spatial data. The findings revealed that between 2008 and 2016, dense vegetation had decreased by 226.98%. Settlements continued to increase to 120.29 percent during that same period. The study also revealed that the land market was lucrative and the resultant implications are on livelihoods and ecology. The study recommends proper planning policies, development of an eco-city model and affordable housing in the inner cities

Classification techniques for arrhythmia patterns using convolutional neural networks and Internet of Things (IoT) devices

The rise of Telemedicine has revolutionized how patients are being treated, leading to several advantages such as enhanced health analysis tools, accessible remote healthcare, basic diagnostic of health parameters, etc. The advent of the Internet of Things (IoT), Artificial Intelligence (AI) and their incorporation into Telemedicine extends the potential of health benefits of Telemedicine even further. Therefore, the synergy between AI, IoT, and Telemedicine creates diverse innovative scenarios for integrating cyber-physical systems into medical health to provide remote monitoring and interactive assistance to patients. Data from World Health Organization reports that 7.4 million people died because of Atrial Fibrillation (AF), recognizing the most common arrhythmia associated with human heart rate. Causes like unhealthy diet, smoking, poor resources to go to the doctor and based on research studies, about 12 and 17.9 million of people will be suffering the AF in the USA and Europe, in 2050 and 2060, respectively. The AF as a cardiovascular disease is becoming an important public health issue to tackle. By using a systematic approach, this paper reviews recent contributions related to the acquisition of heart beats, arrhythmia detection, IoT, and visualization. In particular, by analysing the most closely related papers on Convolutional Neural Network (CNN) and IoT devices in heart disease diagnostics, we present a summary of the main research gaps with suggested directions for future research

Yield performance of cassava genotypes in the forest and coastal ecologies of Southern Ghana

Root yield performances of 10 cassava genotypes were assessed across six environments to determine stable cassava (Manihot esculenta) cultivar(s) for root yield in southern Ghana. The assessments were carried out in the forest zone (Fumesua), coastal savanna zone (Ohawu) and coastal savanna zone (Pokuase) in the 2007-2008 and 2008-2009 growing seasons. The experimental layout was a randomized complete block design with three replications. Additive main effects and multiplicative interactions analysis (AMMI) indicated that genotype by environment interactions were significant. Genotype 6 (CR52A-25) was the highest yielding genotype with a root yield of 60.33 kg ha-1, while Genotype 9 (CR59-4) had the lowest root yield of 26.86 kg ha-1. Root yield was significantly lower (P = 0.001) at the forest zone compared to the coastal savanna zones

Influenza-Associated Myositis in Children

Abstract. : Background: : Influenza-associated myositis (IAM) is an infrequent and poorly known complication of influenza virus infection in children. The aim of this study was to describe five cases of IAM and to review the literature on IAM in children. Patients and Methods: : We conducted a retrospective analysis of cases of IAM diagnosed at two university children's hospitals in Switzerland during two consecutive influenza seasons. Findings were compared with 39 individual case reports and five publications summarizing an additional 272 cases identified by a medical online library (MEDLINE) search. Results: : Overall, 316 cases were analyzed. IAM typically occurred in school-aged children with a 2:1 male predominance. Influenza B and A viruses were identified in 76% and 24% of cases, respectively. The median interval between onset of influenza and onset of IAM was 3 days (range 0-18). The calf muscles were involved alone or together with other muscle groups in 69% and 31% of cases, respectively. Blood creatine phosphokinase (CPK) concentration was invariably elevated. Median duration to clinical recovery was 3 days (range 1-30). Rhabdomyolysis occurred in ten of 316 patients (3%), was more common in girls (80%), more often associated with influenza A (86%), and led to renal failure in eight patients (80%). Conclusion: : Clinical and laboratory findings of IAM are highly characteristic and allow a rapid diagnosis during the influenza seaso

Fashionable Loafers for Male Students

Male students of the Department of Integrated Rural Art and Industry, Kwame Nkrumah University of Science and Technology, Kumasi have preference for three kinds of footwear: loafers, boots, and dressing shoes. They rate loafers as highly preferred for three main reasons: trendiness, adaptability, and economy. This research aimed to design and produce fashionable loafers for male students. The descriptive research method was used to give details about the tools and materials used for the footwear, and the processes for making the loafers. The participatory product design method was used, where the would-be users of the footwear were involved in the design process – they were consulted for their views and comments right from the early design stages till actualisation of the product. The target population was 150 male students of the said Department; 100 were accessible. The simple random sampling method was used; data was collected through interviews and observation. The study recognised that the popularity, acceptability or attractiveness of the first pair of loafers can be seen in 3 ways: African wear or the look alike, the use of beads, and youthfulness of colour. Adaptability and economy of footwear do show up in the varied application of colour and material, for multipurpose use of the footwear. The integration of locally obtainable materials (beads, fabric and leather) and necessary design factors were determined after which manufacturing operations such as pattern cutting, closing, lasting, attaching, arrangement of beads, and finishing were gone through to realize the shoes. Two pairs of loafers were produced; one has bright and lively colours, the other, relatively darker but appealing colours. Keywords: Male students, fashionable, loafers, adaptability, econom

A resilient 2-D waveguide communication fabric for hybrid wired-wireless NoC design

Hybrid wired-wireless Network-on-Chip (WiNoC) has emerged as an alternative solution to the poor scalability and performance issues of conventional wireline NoC design for future System-on-Chip (SoC). Existing feasible wireless solution for WiNoCs in the form of millimeter wave (mm-Wave) relies on free space signal radiation which has high power dissipation with high degradation rate in the signal strength per transmission distance. Moreover, over the lossy wireless medium, combining wireless and wireline channels drastically reduces the total reliability of the communication fabric. Surface wave has been proposed as an alternative wireless technology for low power on-chip communication. With the right design considerations, the reliability and performance benefits of the surface wave channel could be extended. In this paper, we propose a surface wave communication fabric for emerging WiNoCs that is able to match the reliability of traditional wireline NoCs. First, we propose a realistic channel model which demonstrates that existing mm-Wave WiNoCs suffers from not only free-space spreading loss (FSSL) but also molecular absorption attenuation (MAA), especially at high frequency band, which reduces the reliability of the system. Consequently, we employ a carefully designed transducer and commercially available thin metal conductor coated with a low cost dielectric material to generate surface wave signals with improved transmission gain. Our experimental results demonstrate that the proposed communication fabric can achieve a 5dB operational bandwidth of about 60GHz around the center frequency (60GHz). By improving the transmission reliability of wireless layer, the proposed communication fabric can improve maximum sustainable load of NoCs by an average of 20:9% and 133:3% compared to existing WiNoCs and wireline NoCs, respectively

Bundles and Hotspots of Multiple Ecosystem Services for Optimized Land Management in Kentucky, United States

Ecosystem services are benefits that the natural environment provides to support human well-being. A thorough understanding and assessment of these services are critical to maintain ecosystem services flow through sustainable land management to optimize bundles of ecosystem services provision. Maximizing one particular ecosystem service may lead to reduction in another. Therefore, identifying ecosystem services tradeoffs and synergies is key in addressing this challenge. However, the identification of multiple ecosystem services tradeoffs and synergies is still limited. A previous study failed to effectively capture the spatial interaction among ecosystem services as it was limited by “space-to-time” substitution method used because of temporal data scarcity. The study was also limited by using land use types in creating ecosystem services, which could lead to some deviations. The broad objective of this study is therefore to examine the bundles and hotspots of multiple ecosystem services and their tradeoffs in Kentucky, U.S. The study combined geographic data and spatially-explicit models to identify multiple ecosystem services bundles and hotspots, and determined the spatial locations of ecosystem services hotspots. Results showed that the spatial interactions among ecosystem services were very high: of the 21 possible pairs of ecosystem services, 17 pairs were significantly correlated. The seven ecosystem services examined can be bundled into three groups, geographically clustered on the landscape. These results support the hypothesis that some groups of ecosystem services provision can present similar spatial patterns at a large mesoscale. Understanding the spatial interactions and bundles of the ecosystem services provides essential information for evidence-based sustainable land management

SARS-CoV-2 viral dynamic modeling to inform model selection and timing and efficacy of antiviral therapy

Mathematical models of viral dynamics have been reported to describe adequately the dynamical changes of SARS-CoV-2 viral load within an individual host. In this study, eight published viral dynamic models were assessed, and model selection was performed. Viral load data were collected from a community surveillance study, including 2155 measurements from 162 patients (124 household and 38 non-household contacts). An extended version of the target-cell limited model that includes an eclipse phase and an immune response component that enhances viral clearance described best the data. In general, the parameter estimates showed good precision (relative standard error <10), apart from the death rate of infected cells. The parameter estimates were used to simulate the outcomes of a clinical trial of the antiviral AZD7442, a monoclonal antibody combination which blocks infection of the target cells by neutralising the virus. The simulated outcome of the effectiveness of the antiviral therapy in controlling viral replication was in a good agreement with the clinical trial data. Early treatment with high antiviral efficacy is important for desired therapeutic outcome