Soil moisture, organic carbon, and nitrogen content prediction with hyperspectral data using regression models
- Datta, Dristi, Paul, Manoranjan, Murshed, Manzur, Teng, Shyh Wei, Schmidtke, Leigh
- Authors: Datta, Dristi , Paul, Manoranjan , Murshed, Manzur , Teng, Shyh Wei , Schmidtke, Leigh
- Date: 2022
- Type: Text , Journal article
- Relation: Sensors (Basel, Switzerland) Vol. 22, no. 20 (2022), p.
- Full Text:
- Reviewed:
- Description: Soil moisture, soil organic carbon, and nitrogen content prediction are considered significant fields of study as they are directly related to plant health and food production. Direct estimation of these soil properties with traditional methods, for example, the oven-drying technique and chemical analysis, is a time and resource-consuming approach and can predict only smaller areas. With the significant development of remote sensing and hyperspectral (HS) imaging technologies, soil moisture, carbon, and nitrogen can be estimated over vast areas. This paper presents a generalized approach to predicting three different essential soil contents using a comprehensive study of various machine learning (ML) models by considering the dimensional reduction in feature spaces. In this study, we have used three popular benchmark HS datasets captured in Germany and Sweden. The efficacy of different ML algorithms is evaluated to predict soil content, and significant improvement is obtained when a specific range of bands is selected. The performance of ML models is further improved by applying principal component analysis (PCA), a dimensional reduction method that works with an unsupervised learning method. The effect of soil temperature on soil moisture prediction is evaluated in this study, and the results show that when the soil temperature is considered with the HS band, the soil moisture prediction accuracy does not improve. However, the combined effect of band selection and feature transformation using PCA significantly enhances the prediction accuracy for soil moisture, carbon, and nitrogen content. This study represents a comprehensive analysis of a wide range of established ML regression models using data preprocessing, effective band selection, and data dimension reduction and attempt to understand which feature combinations provide the best accuracy. The outcomes of several ML models are verified with validation techniques and the best- and worst-case scenarios in terms of soil content are noted. The proposed approach outperforms existing estimation techniques.
- Authors: Datta, Dristi , Paul, Manoranjan , Murshed, Manzur , Teng, Shyh Wei , Schmidtke, Leigh
- Date: 2022
- Type: Text , Journal article
- Relation: Sensors (Basel, Switzerland) Vol. 22, no. 20 (2022), p.
- Full Text:
- Reviewed:
- Description: Soil moisture, soil organic carbon, and nitrogen content prediction are considered significant fields of study as they are directly related to plant health and food production. Direct estimation of these soil properties with traditional methods, for example, the oven-drying technique and chemical analysis, is a time and resource-consuming approach and can predict only smaller areas. With the significant development of remote sensing and hyperspectral (HS) imaging technologies, soil moisture, carbon, and nitrogen can be estimated over vast areas. This paper presents a generalized approach to predicting three different essential soil contents using a comprehensive study of various machine learning (ML) models by considering the dimensional reduction in feature spaces. In this study, we have used three popular benchmark HS datasets captured in Germany and Sweden. The efficacy of different ML algorithms is evaluated to predict soil content, and significant improvement is obtained when a specific range of bands is selected. The performance of ML models is further improved by applying principal component analysis (PCA), a dimensional reduction method that works with an unsupervised learning method. The effect of soil temperature on soil moisture prediction is evaluated in this study, and the results show that when the soil temperature is considered with the HS band, the soil moisture prediction accuracy does not improve. However, the combined effect of band selection and feature transformation using PCA significantly enhances the prediction accuracy for soil moisture, carbon, and nitrogen content. This study represents a comprehensive analysis of a wide range of established ML regression models using data preprocessing, effective band selection, and data dimension reduction and attempt to understand which feature combinations provide the best accuracy. The outcomes of several ML models are verified with validation techniques and the best- and worst-case scenarios in terms of soil content are noted. The proposed approach outperforms existing estimation techniques.
Application of soft computing to predict blast-induced ground vibration
- Khandelwal, Manoj, Kumar, Lalit, Yellishetty, Mohan
- Authors: Khandelwal, Manoj , Kumar, Lalit , Yellishetty, Mohan
- Date: 2011
- Type: Text , Journal article
- Relation: Engineering with Computers Vol. 27, no. 2 (2011), p. 117-125
- Full Text: false
- Reviewed:
- Description: In this study, an attempt has been made to evaluate and predict the blast-induced ground vibration by incorporating explosive charge per delay and distance from the blast face to the monitoring point using artificial neural network (ANN) technique. A three-layer feed-forward back-propagation neural network with 2-5-1 architecture was trained and tested using 130 experimental and monitored blast records from the surface coal mines of Singareni Collieries Company Limited, Kothagudem, Andhra Pradesh, India. Twenty new blast data sets were used for the validation and comparison of the peak particle velocity (PPV) by ANN and conventional vibration predictors. Results were compared based on coefficient of determination and mean absolute error between monitored and predicted values of PPV. © 2009 Springer-Verlag London Limited.
Comparative analysis of machine and deep learning models for soil properties prediction from hyperspectral visual band
- Datta, Dristi, Paul, Manoranjan, Murshed, Manzur, Teng, Shyh Wei, Schmidtke, Leigh
- Authors: Datta, Dristi , Paul, Manoranjan , Murshed, Manzur , Teng, Shyh Wei , Schmidtke, Leigh
- Date: 2023
- Type: Text , Journal article
- Relation: Environments Vol. 10, no. 5 (2023), p. 77
- Full Text:
- Reviewed:
- Description: Estimating various properties of soil, including moisture, carbon, and nitrogen, is crucial for studying their correlation with plant health and food production. However, conventional methods such as oven-drying and chemical analysis are laborious, expensive, and only feasible for a limited land area. With the advent of remote sensing technologies like multi/hyperspectral imaging, it is now possible to predict soil properties non-invasive and cost-effectively for a large expanse of bare land. Recent research shows the possibility of predicting those soil contents from a wide range of hyperspectral data using good prediction algorithms. However, these kinds of hyperspectral sensors are expensive and not widely available. Therefore, this paper investigates different machine and deep learning techniques to predict soil nutrient properties using only the red (R), green (G), and blue (B) bands data to propose a suitable machine/deep learning model that can be used as a rapid soil test. Another objective of this research is to observe and compare the prediction accuracy in three cases i. hyperspectral band ii. full spectrum of the visual band, and iii. three-channel of RGB band and provide a guideline to the user on which spectrum information they should use to predict those soil properties. The outcome of this research helps to develop a mobile application that is easy to use for a quick soil test. This research also explores learning-based algorithms with significant feature combinations and their performance comparisons in predicting soil properties from visual band data. For this, we also explore the impact of dimensional reduction (i.e., principal component analysis) and transformations (i.e., empirical mode decomposition) of features. The results show that the proposed model can comparably predict the soil contents from the three-channel RGB data.
- Authors: Datta, Dristi , Paul, Manoranjan , Murshed, Manzur , Teng, Shyh Wei , Schmidtke, Leigh
- Date: 2023
- Type: Text , Journal article
- Relation: Environments Vol. 10, no. 5 (2023), p. 77
- Full Text:
- Reviewed:
- Description: Estimating various properties of soil, including moisture, carbon, and nitrogen, is crucial for studying their correlation with plant health and food production. However, conventional methods such as oven-drying and chemical analysis are laborious, expensive, and only feasible for a limited land area. With the advent of remote sensing technologies like multi/hyperspectral imaging, it is now possible to predict soil properties non-invasive and cost-effectively for a large expanse of bare land. Recent research shows the possibility of predicting those soil contents from a wide range of hyperspectral data using good prediction algorithms. However, these kinds of hyperspectral sensors are expensive and not widely available. Therefore, this paper investigates different machine and deep learning techniques to predict soil nutrient properties using only the red (R), green (G), and blue (B) bands data to propose a suitable machine/deep learning model that can be used as a rapid soil test. Another objective of this research is to observe and compare the prediction accuracy in three cases i. hyperspectral band ii. full spectrum of the visual band, and iii. three-channel of RGB band and provide a guideline to the user on which spectrum information they should use to predict those soil properties. The outcome of this research helps to develop a mobile application that is easy to use for a quick soil test. This research also explores learning-based algorithms with significant feature combinations and their performance comparisons in predicting soil properties from visual band data. For this, we also explore the impact of dimensional reduction (i.e., principal component analysis) and transformations (i.e., empirical mode decomposition) of features. The results show that the proposed model can comparably predict the soil contents from the three-channel RGB data.
- Authors: Mestrom, Sanne
- Date: 2012
- Type: Text , Visual art work
- Full Text:
A survey dataset to evaluate the changes in mobility and transportation due to COVID-19 travel restrictions in Australia, Brazil, China, Ghana, India, Iran, Italy, Norway, South Africa, United States
- Barbieri, Diego, Lou, Baowen, Passavanti, Marco, Hui, Cang, Lam, Louisa
- Authors: Barbieri, Diego , Lou, Baowen , Passavanti, Marco , Hui, Cang , Lam, Louisa
- Date: 2020
- Type: Text , Journal article
- Relation: Data in Brief Vol. 33, no. (2020), p.
- Full Text:
- Reviewed:
- Description: COVID-19 pandemic has heavily impacted the global community. To curb the viral transmission, travel restrictions have been enforced across the world. The dataset documents the mobility disruptions and the modal shifts that have occurred as a consequence of the restrictive measures implemented in ten countries: Australia, Brazil, China, Ghana, India, Iran, Italy, Norway, South Africa and the United States. An online questionnaire was distributed during the period from the 11st to the 31st of May 2020, with a total of 9 394 respondents. The first part of the survey has characterized the frequency of use of all transport modes before and during the enforcement of the restrictions, while the second part of the survey has dealt with perceived risks of contracting COVID-19 from different transport modes and perceived effectiveness of travel mitigation measures. Overall, the dataset (stored in a repository publicly available) can be conveniently used to quantify and understand the modal shifts and people's cognitive behavior towards travel due to COVID-19. The collected responses can be further analysed by considering other demographic and socioeconomic covariates. © 2020 The Author(s). *Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Louisa Lam” is provided in this record*
- Authors: Barbieri, Diego , Lou, Baowen , Passavanti, Marco , Hui, Cang , Lam, Louisa
- Date: 2020
- Type: Text , Journal article
- Relation: Data in Brief Vol. 33, no. (2020), p.
- Full Text:
- Reviewed:
- Description: COVID-19 pandemic has heavily impacted the global community. To curb the viral transmission, travel restrictions have been enforced across the world. The dataset documents the mobility disruptions and the modal shifts that have occurred as a consequence of the restrictive measures implemented in ten countries: Australia, Brazil, China, Ghana, India, Iran, Italy, Norway, South Africa and the United States. An online questionnaire was distributed during the period from the 11st to the 31st of May 2020, with a total of 9 394 respondents. The first part of the survey has characterized the frequency of use of all transport modes before and during the enforcement of the restrictions, while the second part of the survey has dealt with perceived risks of contracting COVID-19 from different transport modes and perceived effectiveness of travel mitigation measures. Overall, the dataset (stored in a repository publicly available) can be conveniently used to quantify and understand the modal shifts and people's cognitive behavior towards travel due to COVID-19. The collected responses can be further analysed by considering other demographic and socioeconomic covariates. © 2020 The Author(s). *Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Louisa Lam” is provided in this record*
Ecosystem services and agriculture in Punjab, India
- Kumar, Lalit, Sandhu, Harpinder
- Authors: Kumar, Lalit , Sandhu, Harpinder
- Date: 2017
- Type: Text , Book chapter
- Relation: Ecosystem Functions and Management: Theory and Practice p. 59-84
- Full Text: false
- Reviewed:
- Description: Agroecosystems supply food, fibre and a range of ecosystem services (ES) to human beings. At the same time, they are dependent on regulating services such as freshwater, biodiversity, healthy soils for their proper functioning. It is known that agricultural activities impact negatively on environment and its resources. We present a case study of agriculture in Punjab, India to reflect how it is supplying food to growing population but also impacting other ES. We conclude by discussing trade-offs between food production and natural resources and discuss options for applying ecosystem based approach for long term sustainability of agroecosystems. © Springer International Publishing AG 2017.
Spatial, temporal, and demographic patterns in prevalence of smoking tobacco use and attributable disease burden in 204 countries and territories, 1990–2019: a systematic analysis from the Global Burden of Disease Study 2019
- Reitsma, Marissa, Kendrick, Parkes, Ababneh, Emad, Abbafati, Cristiana, Rahman, Muhammad Aziz
- Authors: Reitsma, Marissa , Kendrick, Parkes , Ababneh, Emad , Abbafati, Cristiana , Rahman, Muhammad Aziz
- Date: 2021
- Type: Text , Journal article
- Relation: The Lancet Vol. 397, no. 10292 (2021), p. 2337-2360
- Full Text:
- Reviewed:
- Description: Background: Ending the global tobacco epidemic is a defining challenge in global health. Timely and comprehensive estimates of the prevalence of smoking tobacco use and attributable disease burden are needed to guide tobacco control efforts nationally and globally. Methods: We estimated the prevalence of smoking tobacco use and attributable disease burden for 204 countries and territories, by age and sex, from 1990 to 2019 as part of the Global Burden of Diseases, Injuries, and Risk Factors Study. We modelled multiple smoking-related indicators from 3625 nationally representative surveys. We completed systematic reviews and did Bayesian meta-regressions for 36 causally linked health outcomes to estimate non-linear dose-response risk curves for current and former smokers. We used a direct estimation approach to estimate attributable burden, providing more comprehensive estimates of the health effects of smoking than previously available. Findings: Globally in 2019, 1·14 billion (95% uncertainty interval 1·13–1·16) individuals were current smokers, who consumed 7·41 trillion (7·11–7·74) cigarette-equivalents of tobacco in 2019. Although prevalence of smoking had decreased significantly since 1990 among both males (27·5% [26·5–28·5] reduction) and females (37·7% [35·4–39·9] reduction) aged 15 years and older, population growth has led to a significant increase in the total number of smokers from 0·99 billion (0·98–1·00) in 1990. Globally in 2019, smoking tobacco use accounted for 7·69 million (7·16–8·20) deaths and 200 million (185–214) disability-adjusted life-years, and was the leading risk factor for death among males (20·2% [19·3–21·1] of male deaths). 6·68 million [86·9%] of 7·69 million deaths attributable to smoking tobacco use were among current smokers. Interpretation: In the absence of intervention, the annual toll of 7·69 million deaths and 200 million disability-adjusted life-years attributable to smoking will increase over the coming decades. Substantial progress in reducing the prevalence of smoking tobacco use has been observed in countries from all regions and at all stages of development, but a large implementation gap remains for tobacco control. Countries have a clear and urgent opportunity to pass strong, evidence-based policies to accelerate reductions in the prevalence of smoking and reap massive health benefits for their citizens. Funding: Bloomberg Philanthropies and the Bill & Melinda Gates Foundation. © 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Muhammad Aziz Rahman" is provided in this record**
- Authors: Reitsma, Marissa , Kendrick, Parkes , Ababneh, Emad , Abbafati, Cristiana , Rahman, Muhammad Aziz
- Date: 2021
- Type: Text , Journal article
- Relation: The Lancet Vol. 397, no. 10292 (2021), p. 2337-2360
- Full Text:
- Reviewed:
- Description: Background: Ending the global tobacco epidemic is a defining challenge in global health. Timely and comprehensive estimates of the prevalence of smoking tobacco use and attributable disease burden are needed to guide tobacco control efforts nationally and globally. Methods: We estimated the prevalence of smoking tobacco use and attributable disease burden for 204 countries and territories, by age and sex, from 1990 to 2019 as part of the Global Burden of Diseases, Injuries, and Risk Factors Study. We modelled multiple smoking-related indicators from 3625 nationally representative surveys. We completed systematic reviews and did Bayesian meta-regressions for 36 causally linked health outcomes to estimate non-linear dose-response risk curves for current and former smokers. We used a direct estimation approach to estimate attributable burden, providing more comprehensive estimates of the health effects of smoking than previously available. Findings: Globally in 2019, 1·14 billion (95% uncertainty interval 1·13–1·16) individuals were current smokers, who consumed 7·41 trillion (7·11–7·74) cigarette-equivalents of tobacco in 2019. Although prevalence of smoking had decreased significantly since 1990 among both males (27·5% [26·5–28·5] reduction) and females (37·7% [35·4–39·9] reduction) aged 15 years and older, population growth has led to a significant increase in the total number of smokers from 0·99 billion (0·98–1·00) in 1990. Globally in 2019, smoking tobacco use accounted for 7·69 million (7·16–8·20) deaths and 200 million (185–214) disability-adjusted life-years, and was the leading risk factor for death among males (20·2% [19·3–21·1] of male deaths). 6·68 million [86·9%] of 7·69 million deaths attributable to smoking tobacco use were among current smokers. Interpretation: In the absence of intervention, the annual toll of 7·69 million deaths and 200 million disability-adjusted life-years attributable to smoking will increase over the coming decades. Substantial progress in reducing the prevalence of smoking tobacco use has been observed in countries from all regions and at all stages of development, but a large implementation gap remains for tobacco control. Countries have a clear and urgent opportunity to pass strong, evidence-based policies to accelerate reductions in the prevalence of smoking and reap massive health benefits for their citizens. Funding: Bloomberg Philanthropies and the Bill & Melinda Gates Foundation. © 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Muhammad Aziz Rahman" is provided in this record**
Numerical modelling of radiative heat transfer in a polydispersion of ceramic particles under direct high-flux solar irradiation
- Chen, Jingjing, Kumar, Apurv, Coventry, Joe, Kim, Jin-Soo, Lipiński, Wojciech
- Authors: Chen, Jingjing , Kumar, Apurv , Coventry, Joe , Kim, Jin-Soo , Lipiński, Wojciech
- Date: 2022
- Type: Text , Journal article
- Relation: Journal of Quantitative Spectroscopy and Radiative Transfer Vol. 278, no. (2022), p.
- Full Text:
- Reviewed:
- Description: The effects of polydispersity on radiative and interfacial convective heat transfer are investigated in particle–gas two-phase media for solar particle receiver applications. Non-grey radiative transfer is analysed using the collision-based Monte Carlo ray-tracing method. The Mie theory is employed to calculate radiative properties of particles. The finite volume method and the explicit Euler time integration scheme are used to solve the transient energy equations for the particle and gas phases. Three alternative approaches to modelling particle properties and thermal conditions are employed: (i) a novel discrete size model, in which particle groups within discrete size intervals are assigned individual properties and temperatures locally; (ii) a lumped size model, in which integral properties and a single temperature are assigned to the particle phase locally; and (iii) a monodisperse size model, in which properties are evaluated for the Sauter mean diameter of the polydispersion and a single temperature is assigned to the particle phase locally. Strongly size-dependent radiation absorption and interfacial convective heat transfer are predicted with the discrete size model for alumina particles. Particles smaller than 27.4μm located near the aperture absorb the solar irradiation and transfer heat to the gas phase most effectively. The angular spread of the incident solar radiation is found to have a negligible effect on the overall absorption, although the most uniform thermal conditions occur for the solar irradiation with the smallest confinement angle. The overall absorptance of alumina particles is higher by 3.4% and 2.7% than that of iron (III) oxide and mullite particles, respectively. The lumped and monodisperse size models allow for reduction of the computational time at the expense of lower accuracy and limited information about particle properties and thermal conditions. © 2021 The Author(s)
- Authors: Chen, Jingjing , Kumar, Apurv , Coventry, Joe , Kim, Jin-Soo , Lipiński, Wojciech
- Date: 2022
- Type: Text , Journal article
- Relation: Journal of Quantitative Spectroscopy and Radiative Transfer Vol. 278, no. (2022), p.
- Full Text:
- Reviewed:
- Description: The effects of polydispersity on radiative and interfacial convective heat transfer are investigated in particle–gas two-phase media for solar particle receiver applications. Non-grey radiative transfer is analysed using the collision-based Monte Carlo ray-tracing method. The Mie theory is employed to calculate radiative properties of particles. The finite volume method and the explicit Euler time integration scheme are used to solve the transient energy equations for the particle and gas phases. Three alternative approaches to modelling particle properties and thermal conditions are employed: (i) a novel discrete size model, in which particle groups within discrete size intervals are assigned individual properties and temperatures locally; (ii) a lumped size model, in which integral properties and a single temperature are assigned to the particle phase locally; and (iii) a monodisperse size model, in which properties are evaluated for the Sauter mean diameter of the polydispersion and a single temperature is assigned to the particle phase locally. Strongly size-dependent radiation absorption and interfacial convective heat transfer are predicted with the discrete size model for alumina particles. Particles smaller than 27.4μm located near the aperture absorb the solar irradiation and transfer heat to the gas phase most effectively. The angular spread of the incident solar radiation is found to have a negligible effect on the overall absorption, although the most uniform thermal conditions occur for the solar irradiation with the smallest confinement angle. The overall absorptance of alumina particles is higher by 3.4% and 2.7% than that of iron (III) oxide and mullite particles, respectively. The lumped and monodisperse size models allow for reduction of the computational time at the expense of lower accuracy and limited information about particle properties and thermal conditions. © 2021 The Author(s)
Efficient route selection in ad hoc on-demand distance vector routing
- Uddin, Ashraf, Akther, Arnisha, Parvez, Shamima, Stranieri, Andrew
- Authors: Uddin, Ashraf , Akther, Arnisha , Parvez, Shamima , Stranieri, Andrew
- Date: 2017
- Type: Text , Conference paper
- Relation: 20th International Conference of Computer and Information, IICIT 2017; Dhaka, Bangladesh; 22nd-24th December 2017 p. 1-6
- Full Text:
- Reviewed:
- Description: The protocol diversities of mobile ad hoc have already got hold of the field to a peak of a matured and developed area. Still, the restraint of delay and bandwidth of mobile ad hoc network have kept a little room to draft a routing protocol for the pursuit of providing quality of service. In the paper, we proposed protocol namely Efficient Route Selection in Ad Hoc On-Demand Distance Vector Routing. We select the best path among multiple paths from source to destination using covariance and delay. We consider the delay, link stability and energy to devise a covariance-based metric to discover the most balanced path. We also propose a metric for the selection of a node that acts as a local backup node for the most vulnerable nodes on the selected path. We accomplish our implementation in NS3and it shows the more reliable path and less end to end delay than other counterpart protocols.
- Authors: Uddin, Ashraf , Akther, Arnisha , Parvez, Shamima , Stranieri, Andrew
- Date: 2017
- Type: Text , Conference paper
- Relation: 20th International Conference of Computer and Information, IICIT 2017; Dhaka, Bangladesh; 22nd-24th December 2017 p. 1-6
- Full Text:
- Reviewed:
- Description: The protocol diversities of mobile ad hoc have already got hold of the field to a peak of a matured and developed area. Still, the restraint of delay and bandwidth of mobile ad hoc network have kept a little room to draft a routing protocol for the pursuit of providing quality of service. In the paper, we proposed protocol namely Efficient Route Selection in Ad Hoc On-Demand Distance Vector Routing. We select the best path among multiple paths from source to destination using covariance and delay. We consider the delay, link stability and energy to devise a covariance-based metric to discover the most balanced path. We also propose a metric for the selection of a node that acts as a local backup node for the most vulnerable nodes on the selected path. We accomplish our implementation in NS3and it shows the more reliable path and less end to end delay than other counterpart protocols.
A kernel density estimation approach and statistical generalized additive model of Western North Pacific typhoon activities
- Wang, Xiang, Wahiduzzaman, Md, Yeasmin, Alea
- Authors: Wang, Xiang , Wahiduzzaman, Md , Yeasmin, Alea
- Date: 2022
- Type: Text , Journal article
- Relation: Atmosphere Vol. 13, no. 7 (2022), p.
- Full Text:
- Reviewed:
- Description: This paper presents a development of a statistical model of typhoon genesis, tracks based on kernel density estimation and a generalized additive model (GAM). Modeling of typhoon activity is ultimately beneficial to the people living in coastal zones, insurance/re-insurance companies, policy, planning and decision departments. A 50-year record (1972–2021) of typhoon track observations from the International Best Track Archive Climate Stewardship have been used to observe the distribution of typhoon genesis by kernel density estimation. The tracks are simulated through the development of a GAM. It reproduces the observation well. A distance calculation approach between observed and simulated tracks’ landfall have been used to validate the model and the model shows a very good skill (approximately 75%). © 2022 by the authors.
- Authors: Wang, Xiang , Wahiduzzaman, Md , Yeasmin, Alea
- Date: 2022
- Type: Text , Journal article
- Relation: Atmosphere Vol. 13, no. 7 (2022), p.
- Full Text:
- Reviewed:
- Description: This paper presents a development of a statistical model of typhoon genesis, tracks based on kernel density estimation and a generalized additive model (GAM). Modeling of typhoon activity is ultimately beneficial to the people living in coastal zones, insurance/re-insurance companies, policy, planning and decision departments. A 50-year record (1972–2021) of typhoon track observations from the International Best Track Archive Climate Stewardship have been used to observe the distribution of typhoon genesis by kernel density estimation. The tracks are simulated through the development of a GAM. It reproduces the observation well. A distance calculation approach between observed and simulated tracks’ landfall have been used to validate the model and the model shows a very good skill (approximately 75%). © 2022 by the authors.
Quality management practices in SMEs : a comparative study between India and Namibia
- Chakraborty, Ayon, Mutingi, Michael, Vashishth, Abhishek
- Authors: Chakraborty, Ayon , Mutingi, Michael , Vashishth, Abhishek
- Date: 2019
- Type: Text , Journal article
- Relation: Benchmarking Vol. 26, no. 5 (2019), p. 1499-1516
- Full Text:
- Reviewed:
- Description: Purpose: Small- and medium-sized enterprises (SMEs) have now become an important part of economy for not only developed nations but also for emerging economies. Irrespective of the benefits that can be derived, SMEs in emerging economies still lack the will to implement quality management (QM) practices. Using a comparative study, the purpose of this paper is to understand the status of QM practices in SMEs of emerging economies. Design/methodology/approach: A survey-based approach was adopted to understand the established QM practices in the SMEs. A survey instrument was designed by reviewing the literature on QM initiatives in SMEs. A sample of 270 SMEs across Southern India and 189 SMEs in Namibia was selected through stratified random sampling technique. Findings: The overall response rate was 19.52 percent for India and 26.46 percent for Namibia, respectively. There were similarities and differences in responses from SMEs in both countries. Similarities are in terms of limited implementation of QM practices, and also less use of tools and techniques. Reasons for not implementing include unknown to the authors, and the high cost of training. Differences emerged in the type of market (Indian SMEs catering to one major customer), CSFs and business performance indicators. It was interesting to find that management commitment and involvement do not have a major influence as CSF for SMEs in both the countries. Originality/value: The research is the first attempt in bringing a comparative study about QM practices in SMEs from developing countries. The insights will help emerging economies to develop policies for education and training, and thus facilitate implementation of QM practices in SMEs. © 2019, Emerald Publishing Limited.
- Authors: Chakraborty, Ayon , Mutingi, Michael , Vashishth, Abhishek
- Date: 2019
- Type: Text , Journal article
- Relation: Benchmarking Vol. 26, no. 5 (2019), p. 1499-1516
- Full Text:
- Reviewed:
- Description: Purpose: Small- and medium-sized enterprises (SMEs) have now become an important part of economy for not only developed nations but also for emerging economies. Irrespective of the benefits that can be derived, SMEs in emerging economies still lack the will to implement quality management (QM) practices. Using a comparative study, the purpose of this paper is to understand the status of QM practices in SMEs of emerging economies. Design/methodology/approach: A survey-based approach was adopted to understand the established QM practices in the SMEs. A survey instrument was designed by reviewing the literature on QM initiatives in SMEs. A sample of 270 SMEs across Southern India and 189 SMEs in Namibia was selected through stratified random sampling technique. Findings: The overall response rate was 19.52 percent for India and 26.46 percent for Namibia, respectively. There were similarities and differences in responses from SMEs in both countries. Similarities are in terms of limited implementation of QM practices, and also less use of tools and techniques. Reasons for not implementing include unknown to the authors, and the high cost of training. Differences emerged in the type of market (Indian SMEs catering to one major customer), CSFs and business performance indicators. It was interesting to find that management commitment and involvement do not have a major influence as CSF for SMEs in both the countries. Originality/value: The research is the first attempt in bringing a comparative study about QM practices in SMEs from developing countries. The insights will help emerging economies to develop policies for education and training, and thus facilitate implementation of QM practices in SMEs. © 2019, Emerald Publishing Limited.
Development of a long-term climatology of tropical 1 cyclones and depressions for the South Pacific 2 Ocean basin
- Authors: Yeasmin, Alea
- Date: 2023
- Type: Text , Thesis , PhD
- Full Text:
- Description: Tropical cyclones (TCs) are one of the most destructive synoptic systems that can cause enormous loss of life and property damages in the South Pacific Island nations. The impact of tropical depressions (TDs, i.e., weaker systems that do not develop into TCs) can also be staggering in the region in terms of heavy flooding and landslides, but a lack of complete records (reliable data prior to 1950) often hinders research involving TD impacts. A methodology has been developed here to detect TDs in the ERA-5 (the fifth generation European Centre for Medium-Range Weather Forecasts-ECMWF atmospheric reanalysis of the global climate) and 20CR (the Twentieth Century Reanalysis) dataset using the Okubo–Weiss–Zeta parameter (OWZP) detection scheme. The new South Pacific Enhanced Archive for Tropical Cyclones dataset (SPEArTC), the Dvorak analysis of satellite-based cloud patterns over the South Pacific Ocean basin, rainfall dataset for various stations in the South Pacific and historical archives have been utilised to validate ERA5/20CR-derived TCs and TDs. Results indicate that the OWZP method shows substantial skill in capturing the realistic climatological distribution of TCs and TDs for the South Pacific Ocean in both reanalyses dataset. The 20CR-derived TCs and TDs resemble several key characteristics of the observational records, including spatial distribution of genesis locations and track shapes. This gives us confidence that the 20CR-derived long-term records of TCs and TDs can serve as an effective tool for examining historical changes in various characteristics of TCs and TDs, particularly in the context of anthropogenic climate change. Utilizing the reconstructed proxies of TCs and TDs, their climatic connections with the El Niño Southern Oscillation (ENSO), the Interdecadal Pacific Oscillation (IPO), and the combined ENSO-IPO phases have been examined. Results show clear spatial shifts in TC activity between La Niña and El Niño phases with activity in the region 1400-1700E (1700-2200E) occurring during La Niña (El Niño) events. However, when IPO is considered synergistically with ENSO phases, we found that the combination of El Niño and the positive phase of IPO (+IPO) substantially enhances TC numbers (may be artifact influence) in both domains, noting the modulation between the two phases themselves. Similarly, La Niña and the negative phase of the IPO (-IPO) is found to enhance TC numbers in 1400-1700E. It is shown for the first time that the combined phases of El Niño and +IPO account for increased TC activity, as opposed to the combined phase of La Niña and -IPO, in the eastern sub-region. Similarly, the combined phase of La Niña and +IPO, as opposed to the combined phase of El Niño and -IPO, account for increased TC activity in the western sub-region. However, unlike TCs, the patterns of ENSO variability seem to be reversed for TDs. Changes in large-scale environmental conditions, such as environmental vertical wind shear, low-level cyclonic relative vorticity, mid-tropospheric relative humidity and sea surface temperature are linked to the various modes of variability patterns and their synergistic relationships. Results can have substantial implications, particularly on the predictability of TCs and TDs associated with the two important modes of natural variability in the South Pacific.
- Description: Doctor of Philosophy
- Authors: Yeasmin, Alea
- Date: 2023
- Type: Text , Thesis , PhD
- Full Text:
- Description: Tropical cyclones (TCs) are one of the most destructive synoptic systems that can cause enormous loss of life and property damages in the South Pacific Island nations. The impact of tropical depressions (TDs, i.e., weaker systems that do not develop into TCs) can also be staggering in the region in terms of heavy flooding and landslides, but a lack of complete records (reliable data prior to 1950) often hinders research involving TD impacts. A methodology has been developed here to detect TDs in the ERA-5 (the fifth generation European Centre for Medium-Range Weather Forecasts-ECMWF atmospheric reanalysis of the global climate) and 20CR (the Twentieth Century Reanalysis) dataset using the Okubo–Weiss–Zeta parameter (OWZP) detection scheme. The new South Pacific Enhanced Archive for Tropical Cyclones dataset (SPEArTC), the Dvorak analysis of satellite-based cloud patterns over the South Pacific Ocean basin, rainfall dataset for various stations in the South Pacific and historical archives have been utilised to validate ERA5/20CR-derived TCs and TDs. Results indicate that the OWZP method shows substantial skill in capturing the realistic climatological distribution of TCs and TDs for the South Pacific Ocean in both reanalyses dataset. The 20CR-derived TCs and TDs resemble several key characteristics of the observational records, including spatial distribution of genesis locations and track shapes. This gives us confidence that the 20CR-derived long-term records of TCs and TDs can serve as an effective tool for examining historical changes in various characteristics of TCs and TDs, particularly in the context of anthropogenic climate change. Utilizing the reconstructed proxies of TCs and TDs, their climatic connections with the El Niño Southern Oscillation (ENSO), the Interdecadal Pacific Oscillation (IPO), and the combined ENSO-IPO phases have been examined. Results show clear spatial shifts in TC activity between La Niña and El Niño phases with activity in the region 1400-1700E (1700-2200E) occurring during La Niña (El Niño) events. However, when IPO is considered synergistically with ENSO phases, we found that the combination of El Niño and the positive phase of IPO (+IPO) substantially enhances TC numbers (may be artifact influence) in both domains, noting the modulation between the two phases themselves. Similarly, La Niña and the negative phase of the IPO (-IPO) is found to enhance TC numbers in 1400-1700E. It is shown for the first time that the combined phases of El Niño and +IPO account for increased TC activity, as opposed to the combined phase of La Niña and -IPO, in the eastern sub-region. Similarly, the combined phase of La Niña and +IPO, as opposed to the combined phase of El Niño and -IPO, account for increased TC activity in the western sub-region. However, unlike TCs, the patterns of ENSO variability seem to be reversed for TDs. Changes in large-scale environmental conditions, such as environmental vertical wind shear, low-level cyclonic relative vorticity, mid-tropospheric relative humidity and sea surface temperature are linked to the various modes of variability patterns and their synergistic relationships. Results can have substantial implications, particularly on the predictability of TCs and TDs associated with the two important modes of natural variability in the South Pacific.
- Description: Doctor of Philosophy
Optimization of an ultrasonic-assisted biodiesel production process from one genotype of rapeseed (TERI (OE) R-983) as a novel feedstock using response surface methodology
- Almasi, Sara, Ghobadian, Barat, Najafi, Gholam, Yusaf, Talal, Soufi, Masoud, Hoseini, Seyed
- Authors: Almasi, Sara , Ghobadian, Barat , Najafi, Gholam , Yusaf, Talal , Soufi, Masoud , Hoseini, Seyed
- Date: 2019
- Type: Text , Journal article
- Relation: Energies Vol. 12, no. 14 (2019), p. 1-14
- Full Text:
- Reviewed:
- Description: In recent years, due to the favorable climate conditions of Iran, the cultivation of rapeseed has increased significantly. The aim of this study was to investigate the possibility of biodiesel production from one genotype of rapeseed (TERI (OE) R-983). An ultrasonic approach was used in order to intensify the reaction. Response surface methodology (RSM) was applied to identify the optimum conditions of the process. The results of this research showed that the conversion of biodiesel was found to be 87.175% under the optimized conditions of a 4.63:1 molar ratio (methanol to oil), 56.50% amplitude, and 0.4 s pulses for a reaction time of 5.22 min. Increasing the operating conditions, such as the molar ratio from 4:1 to 5.5:1, amplitude from 50% to 72.5%, reaction time from 3 min to 7 min, and pulse from 0.4 s to 1 s, increased the FAME (fatty acid methyl esters) yield by approximately 4.5%, 2.3%, 1.2%, and 0.5%, respectively. The properties of the TERI (OE) R-983 methyl ester met the requirements of the biodiesel standard (ASTM D6751), indicating the potential of the produced biodiesel as an alternative fuel.
- Authors: Almasi, Sara , Ghobadian, Barat , Najafi, Gholam , Yusaf, Talal , Soufi, Masoud , Hoseini, Seyed
- Date: 2019
- Type: Text , Journal article
- Relation: Energies Vol. 12, no. 14 (2019), p. 1-14
- Full Text:
- Reviewed:
- Description: In recent years, due to the favorable climate conditions of Iran, the cultivation of rapeseed has increased significantly. The aim of this study was to investigate the possibility of biodiesel production from one genotype of rapeseed (TERI (OE) R-983). An ultrasonic approach was used in order to intensify the reaction. Response surface methodology (RSM) was applied to identify the optimum conditions of the process. The results of this research showed that the conversion of biodiesel was found to be 87.175% under the optimized conditions of a 4.63:1 molar ratio (methanol to oil), 56.50% amplitude, and 0.4 s pulses for a reaction time of 5.22 min. Increasing the operating conditions, such as the molar ratio from 4:1 to 5.5:1, amplitude from 50% to 72.5%, reaction time from 3 min to 7 min, and pulse from 0.4 s to 1 s, increased the FAME (fatty acid methyl esters) yield by approximately 4.5%, 2.3%, 1.2%, and 0.5%, respectively. The properties of the TERI (OE) R-983 methyl ester met the requirements of the biodiesel standard (ASTM D6751), indicating the potential of the produced biodiesel as an alternative fuel.
Optimizing 3d printed metallic object’s postprocessing : a case of gamma‐tial alloys
- Chowdhury, M. A. K., Sharif Ullah, A., Teti, Roberto
- Authors: Chowdhury, M. A. K. , Sharif Ullah, A. , Teti, Roberto
- Date: 2021
- Type: Text , Journal article
- Relation: Materials Vol. 14, no. 5 (2021), p. 1-15
- Full Text:
- Reviewed:
- Description: Gamma‐TiAl (γ‐TiAl) alloys can be used in high‐end products relevant to the aerospace, defense, biomedical, and marine industries. Fabricating objects made of γ‐TiAl alloys needs an additive manufacturing process called Electron Beam Melting (EBM) or other similar processes because these alloys are difficult‐to‐cut materials. An object fabricated by EBM exhibits poor surface finish and must undergo postprocessing. In this study, cylindrical specimens were fabricated by EBM and post‐processed by turning at different cutting conditions (cutting speed, depth of cut, feed rate, insert radius, and coolant flowrate). The EBM conditions were as follows: average powder size 110 μm, acceleration voltage 60 kV, beam current 10 mA, beam scanning speed 2200 mm/s, and beam focus offset 0.20 mm. The surface roughness and cutting force were recorded for each set of cutting conditions. The values of the cutting conditions were set by the L36 Design of Experiment approach. The effects of the cutting conditions on surface roughness and cutting force are elucidated by constructing the possibility distributions (triangular fuzzy numbers) from the experimental data. Finally, the optimal cutting conditions to improve the surface finish of specimens made of γ‐TiAl alloys are determined using the possibility distributions. Thus, this study’s outcomes can be used to develop intelligent systems for optimizing additive manufacturing processes. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
- Authors: Chowdhury, M. A. K. , Sharif Ullah, A. , Teti, Roberto
- Date: 2021
- Type: Text , Journal article
- Relation: Materials Vol. 14, no. 5 (2021), p. 1-15
- Full Text:
- Reviewed:
- Description: Gamma‐TiAl (γ‐TiAl) alloys can be used in high‐end products relevant to the aerospace, defense, biomedical, and marine industries. Fabricating objects made of γ‐TiAl alloys needs an additive manufacturing process called Electron Beam Melting (EBM) or other similar processes because these alloys are difficult‐to‐cut materials. An object fabricated by EBM exhibits poor surface finish and must undergo postprocessing. In this study, cylindrical specimens were fabricated by EBM and post‐processed by turning at different cutting conditions (cutting speed, depth of cut, feed rate, insert radius, and coolant flowrate). The EBM conditions were as follows: average powder size 110 μm, acceleration voltage 60 kV, beam current 10 mA, beam scanning speed 2200 mm/s, and beam focus offset 0.20 mm. The surface roughness and cutting force were recorded for each set of cutting conditions. The values of the cutting conditions were set by the L36 Design of Experiment approach. The effects of the cutting conditions on surface roughness and cutting force are elucidated by constructing the possibility distributions (triangular fuzzy numbers) from the experimental data. Finally, the optimal cutting conditions to improve the surface finish of specimens made of γ‐TiAl alloys are determined using the possibility distributions. Thus, this study’s outcomes can be used to develop intelligent systems for optimizing additive manufacturing processes. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Cancer incidence, mortality, years of life lost, years lived with disability, and disability-adjusted life years for 29 cancer groups from 2010 to 2019 a systematic analysis for the global burden of disease study 2019
- Kocarnik, Jonathan, Compton, Kelly, Dean, Fean, Fu, Weijia, Gaw, Brian, Harvey, James, Henrikson, Hannah, Lu, Dan, Pennini, Alyssa, Xu, Rixing, Ababneh, Emad, Abbasi-Kangevari, Mohsen, Abbastabar, Hedayat, Abd-Elsalam, Sherief, Abdoli, Amir, Abedi, Aidin, Abidi, Hassan, Abolhassani, Hassan, Adedeji, Isaac, Adnani, Qorinath, Advani, Shailesh, Afzal, Muhammad, Aghaali, Mohammad, Ahinkorah, Bright, Ahmad, Sajjad, Ahmad, Tauseef, Ahmadi, Ali, Ahmadi, Sepideh, Ahmed Rashid, Tarik, Rahman, Muhammad Aziz
- Authors: Kocarnik, Jonathan , Compton, Kelly , Dean, Fean , Fu, Weijia , Gaw, Brian , Harvey, James , Henrikson, Hannah , Lu, Dan , Pennini, Alyssa , Xu, Rixing , Ababneh, Emad , Abbasi-Kangevari, Mohsen , Abbastabar, Hedayat , Abd-Elsalam, Sherief , Abdoli, Amir , Abedi, Aidin , Abidi, Hassan , Abolhassani, Hassan , Adedeji, Isaac , Adnani, Qorinath , Advani, Shailesh , Afzal, Muhammad , Aghaali, Mohammad , Ahinkorah, Bright , Ahmad, Sajjad , Ahmad, Tauseef , Ahmadi, Ali , Ahmadi, Sepideh , Ahmed Rashid, Tarik , Rahman, Muhammad Aziz
- Date: 2022
- Type: Text , Journal article
- Relation: JAMA Oncology Vol. 8, no. 3 (2022), p. 420-444
- Full Text:
- Reviewed:
- Description: IMPORTANCE The Global Burden of Diseases, Injuries, and Risk Factors Study 2019 (GBD 2019) provided systematic estimates of incidence, morbidity, and mortality to inform local and international efforts toward reducing cancer burden. OBJECTIVE To estimate cancer burden and trends globally for 204 countries and territories and by Sociodemographic Index (SDI) quintiles from 2010 to 2019. EVIDENCE REVIEW The GBD 2019 estimation methods were used to describe cancer incidence, mortality, years lived with disability, years of life lost, and disability-adjusted life years (DALYs) in 2019 and over the past decade. Estimates are also provided by quintiles of the SDI, a composite measure of educational attainment, income per capita, and total fertility rate for those younger than 25 years. Estimates include 95% uncertainty intervals (UIs). FINDINGS In 2019, there were an estimated 23.6 million (95% UI, 22.2-24.9 million) new cancer cases (17.2 million when excluding nonmelanoma skin cancer) and 10.0 million (95% UI, 9.36-10.6 million) cancer deaths globally, with an estimated 250 million (235-264 million) DALYs due to cancer. Since 2010, these represented a 26.3% (95% UI, 20.3%-32.3%) increase in new cases, a 20.9% (95% UI, 14.2%-27.6%) increase in deaths, and a 16.0% (95% UI, 9.3%-22.8%) increase in DALYs. Among 22 groups of diseases and injuries in the GBD 2019 study, cancer was second only to cardiovascular diseases for the number of deaths, years of life lost, and DALYs globally in 2019. Cancer burden differed across SDI quintiles. The proportion of years lived with disability that contributed to DALYs increased with SDI, ranging from 1.4% (1.1%-1.8%) in the low SDI quintile to 5.7% (4.2%-7.1%) in the high SDI quintile. While the high SDI quintile had the highest number of new cases in 2019, the middle SDI quintile had the highest number of cancer deaths and DALYs. From 2010 to 2019, the largest percentage increase in the numbers of cases and deaths occurred in the low and low-middle SDI quintiles. CONCLUSIONS AND RELEVANCE The results of this systematic analysis suggest that the global burden of cancer is substantial and growing, with burden differing by SDI. These results provide comprehensive and comparable estimates that can potentially inform efforts toward equitable cancer control around the world. © 2022 American Medical Association. All rights reserved. **Please note that there are multiple authors for this article therefore only the name of the first 30 including Federation University Australia affiliate “Muhammad Aziz Rahman" is provided in this record**
- Authors: Kocarnik, Jonathan , Compton, Kelly , Dean, Fean , Fu, Weijia , Gaw, Brian , Harvey, James , Henrikson, Hannah , Lu, Dan , Pennini, Alyssa , Xu, Rixing , Ababneh, Emad , Abbasi-Kangevari, Mohsen , Abbastabar, Hedayat , Abd-Elsalam, Sherief , Abdoli, Amir , Abedi, Aidin , Abidi, Hassan , Abolhassani, Hassan , Adedeji, Isaac , Adnani, Qorinath , Advani, Shailesh , Afzal, Muhammad , Aghaali, Mohammad , Ahinkorah, Bright , Ahmad, Sajjad , Ahmad, Tauseef , Ahmadi, Ali , Ahmadi, Sepideh , Ahmed Rashid, Tarik , Rahman, Muhammad Aziz
- Date: 2022
- Type: Text , Journal article
- Relation: JAMA Oncology Vol. 8, no. 3 (2022), p. 420-444
- Full Text:
- Reviewed:
- Description: IMPORTANCE The Global Burden of Diseases, Injuries, and Risk Factors Study 2019 (GBD 2019) provided systematic estimates of incidence, morbidity, and mortality to inform local and international efforts toward reducing cancer burden. OBJECTIVE To estimate cancer burden and trends globally for 204 countries and territories and by Sociodemographic Index (SDI) quintiles from 2010 to 2019. EVIDENCE REVIEW The GBD 2019 estimation methods were used to describe cancer incidence, mortality, years lived with disability, years of life lost, and disability-adjusted life years (DALYs) in 2019 and over the past decade. Estimates are also provided by quintiles of the SDI, a composite measure of educational attainment, income per capita, and total fertility rate for those younger than 25 years. Estimates include 95% uncertainty intervals (UIs). FINDINGS In 2019, there were an estimated 23.6 million (95% UI, 22.2-24.9 million) new cancer cases (17.2 million when excluding nonmelanoma skin cancer) and 10.0 million (95% UI, 9.36-10.6 million) cancer deaths globally, with an estimated 250 million (235-264 million) DALYs due to cancer. Since 2010, these represented a 26.3% (95% UI, 20.3%-32.3%) increase in new cases, a 20.9% (95% UI, 14.2%-27.6%) increase in deaths, and a 16.0% (95% UI, 9.3%-22.8%) increase in DALYs. Among 22 groups of diseases and injuries in the GBD 2019 study, cancer was second only to cardiovascular diseases for the number of deaths, years of life lost, and DALYs globally in 2019. Cancer burden differed across SDI quintiles. The proportion of years lived with disability that contributed to DALYs increased with SDI, ranging from 1.4% (1.1%-1.8%) in the low SDI quintile to 5.7% (4.2%-7.1%) in the high SDI quintile. While the high SDI quintile had the highest number of new cases in 2019, the middle SDI quintile had the highest number of cancer deaths and DALYs. From 2010 to 2019, the largest percentage increase in the numbers of cases and deaths occurred in the low and low-middle SDI quintiles. CONCLUSIONS AND RELEVANCE The results of this systematic analysis suggest that the global burden of cancer is substantial and growing, with burden differing by SDI. These results provide comprehensive and comparable estimates that can potentially inform efforts toward equitable cancer control around the world. © 2022 American Medical Association. All rights reserved. **Please note that there are multiple authors for this article therefore only the name of the first 30 including Federation University Australia affiliate “Muhammad Aziz Rahman" is provided in this record**
Age–sex differences in the global burden of lower respiratory infections and risk factors, 1990–2019 : results from the Global Burden of Disease Study 2019
- Kyu, Hmwe, Vongpradith, Avina, Sirota, Sarah, Novotney, Amanda, Troeger, Christopher, Doxey, Matthew, Bender, Rose, Ledesma, Jorge, Biehl, Molly, Albertson, Samuel, Frostad, Joseph, Burkart, Katrin, Bennitt, Fiona, Zhao, Jeff, Gardner, William, Hagins, Hailey, Bryazka, Dana, Dominguez, Regina, Abate, Semagn, Abdelmasseh, Michael, Abdoli, Amir, Abdoli, Gholamreza, Abedi, Aidin, Abedi, Vida, Abegaz, Tadesse, Abidi, Hassan, Aboagye, Richard, Nguyen, Huy, Rahman, Muhammad Aziz
- Authors: Kyu, Hmwe , Vongpradith, Avina , Sirota, Sarah , Novotney, Amanda , Troeger, Christopher , Doxey, Matthew , Bender, Rose , Ledesma, Jorge , Biehl, Molly , Albertson, Samuel , Frostad, Joseph , Burkart, Katrin , Bennitt, Fiona , Zhao, Jeff , Gardner, William , Hagins, Hailey , Bryazka, Dana , Dominguez, Regina , Abate, Semagn , Abdelmasseh, Michael , Abdoli, Amir , Abdoli, Gholamreza , Abedi, Aidin , Abedi, Vida , Abegaz, Tadesse , Abidi, Hassan , Aboagye, Richard , Nguyen, Huy , Rahman, Muhammad Aziz
- Date: 2022
- Type: Text , Journal article
- Relation: The Lancet Infectious Diseases Vol. 22, no. 11 (2022), p. 1626-1647
- Full Text:
- Reviewed:
- Description: Background: The global burden of lower respiratory infections (LRIs) and corresponding risk factors in children older than 5 years and adults has not been studied as comprehensively as it has been in children younger than 5 years. We assessed the burden and trends of LRIs and risk factors across all age groups by sex, for 204 countries and territories. Methods: In this analysis of data for the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, we used clinician-diagnosed pneumonia or bronchiolitis as our case definition for LRIs. We included International Classification of Diseases 9th edition codes 079.6, 466–469, 470.0, 480–482.8, 483.0–483.9, 484.1–484.2, 484.6–484.7, and 487–489 and International Classification of Diseases 10th edition codes A48.1, A70, B97.4–B97.6, J09–J15.8, J16–J16.9, J20–J21.9, J91.0, P23.0–P23.4, and U04–U04.9. We used the Cause of Death Ensemble modelling strategy to analyse 23 109 site-years of vital registration data, 825 site-years of sample vital registration data, 1766 site-years of verbal autopsy data, and 681 site-years of mortality surveillance data. We used DisMod-MR 2.1, a Bayesian meta-regression tool, to analyse age–sex-specific incidence and prevalence data identified via systematic reviews of the literature, population-based survey data, and claims and inpatient data. Additionally, we estimated age–sex-specific LRI mortality that is attributable to the independent effects of 14 risk factors. Findings: Globally, in 2019, we estimated that there were 257 million (95% uncertainty interval [UI] 240–275) LRI incident episodes in males and 232 million (217–248) in females. In the same year, LRIs accounted for 1·30 million (95% UI 1·18–1·42) male deaths and 1·20 million (1·07–1·33) female deaths. Age-standardised incidence and mortality rates were 1·17 times (95% UI 1·16–1·18) and 1·31 times (95% UI 1·23–1·41) greater in males than in females in 2019. Between 1990 and 2019, LRI incidence and mortality rates declined at different rates across age groups and an increase in LRI episodes and deaths was estimated among all adult age groups, with males aged 70 years and older having the highest increase in LRI episodes (126·0% [95% UI 121·4–131·1]) and deaths (100·0% [83·4–115·9]). During the same period, LRI episodes and deaths in children younger than 15 years were estimated to have decreased, and the greatest decline was observed for LRI deaths in males younger than 5 years (–70·7% [–77·2 to –61·8]). The leading risk factors for LRI mortality varied across age groups and sex. More than half of global LRI deaths in children younger than 5 years were attributable to child wasting (population attributable fraction [PAF] 53·0% [95% UI 37·7–61·8] in males and 56·4% [40·7–65·1] in females), and more than a quarter of LRI deaths among those aged 5–14 years were attributable to household air pollution (PAF 26·0% [95% UI 16·6–35·5] for males and PAF 25·8% [16·3–35·4] for females). PAFs of male LRI deaths attributed to smoking were 20·4% (95% UI 15·4–25·2) in those aged 15–49 years, 30·5% (24·1–36·9) in those aged 50–69 years, and 21·9% (16·8–27·3) in those aged 70 years and older. PAFs of female LRI deaths attributed to household air pollution were 21·1% (95% UI 14·5–27·9) in those aged 15–49 years and 18·2% (12·5–24·5) in those aged 50–69 years. For females aged 70 years and older, the leading risk factor, ambient particulate matter, was responsible for 11·7% (95% UI 8·2–15·8) of LRI deaths. Interpretation: The patterns and progress in reducing the burden of LRIs and key risk factors for mortality varied across age groups and sexes. The progress seen in children younger than 5 years was clearly a result of targeted interventions, such as vaccination and reduction of exposure to risk factors. Similar interventions for other age groups could contribute to the achievement of multiple Sustainable Development Goals targets, including promoting well eing at all ages and reducing health inequalities. Interventions, including addressing risk factors such as child wasting, smoking, ambient particulate matter pollution, and household air pollution, would prevent deaths and reduce health disparities. Funding: Bill & Melinda Gates Foundation. © 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license **Please note that there are multiple authors for this article therefore only the name of the first 30 including Federation University Australia affiliate “Muhammad Aziz Rahman and Huy Nguyen” is provided in this record**
- Authors: Kyu, Hmwe , Vongpradith, Avina , Sirota, Sarah , Novotney, Amanda , Troeger, Christopher , Doxey, Matthew , Bender, Rose , Ledesma, Jorge , Biehl, Molly , Albertson, Samuel , Frostad, Joseph , Burkart, Katrin , Bennitt, Fiona , Zhao, Jeff , Gardner, William , Hagins, Hailey , Bryazka, Dana , Dominguez, Regina , Abate, Semagn , Abdelmasseh, Michael , Abdoli, Amir , Abdoli, Gholamreza , Abedi, Aidin , Abedi, Vida , Abegaz, Tadesse , Abidi, Hassan , Aboagye, Richard , Nguyen, Huy , Rahman, Muhammad Aziz
- Date: 2022
- Type: Text , Journal article
- Relation: The Lancet Infectious Diseases Vol. 22, no. 11 (2022), p. 1626-1647
- Full Text:
- Reviewed:
- Description: Background: The global burden of lower respiratory infections (LRIs) and corresponding risk factors in children older than 5 years and adults has not been studied as comprehensively as it has been in children younger than 5 years. We assessed the burden and trends of LRIs and risk factors across all age groups by sex, for 204 countries and territories. Methods: In this analysis of data for the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, we used clinician-diagnosed pneumonia or bronchiolitis as our case definition for LRIs. We included International Classification of Diseases 9th edition codes 079.6, 466–469, 470.0, 480–482.8, 483.0–483.9, 484.1–484.2, 484.6–484.7, and 487–489 and International Classification of Diseases 10th edition codes A48.1, A70, B97.4–B97.6, J09–J15.8, J16–J16.9, J20–J21.9, J91.0, P23.0–P23.4, and U04–U04.9. We used the Cause of Death Ensemble modelling strategy to analyse 23 109 site-years of vital registration data, 825 site-years of sample vital registration data, 1766 site-years of verbal autopsy data, and 681 site-years of mortality surveillance data. We used DisMod-MR 2.1, a Bayesian meta-regression tool, to analyse age–sex-specific incidence and prevalence data identified via systematic reviews of the literature, population-based survey data, and claims and inpatient data. Additionally, we estimated age–sex-specific LRI mortality that is attributable to the independent effects of 14 risk factors. Findings: Globally, in 2019, we estimated that there were 257 million (95% uncertainty interval [UI] 240–275) LRI incident episodes in males and 232 million (217–248) in females. In the same year, LRIs accounted for 1·30 million (95% UI 1·18–1·42) male deaths and 1·20 million (1·07–1·33) female deaths. Age-standardised incidence and mortality rates were 1·17 times (95% UI 1·16–1·18) and 1·31 times (95% UI 1·23–1·41) greater in males than in females in 2019. Between 1990 and 2019, LRI incidence and mortality rates declined at different rates across age groups and an increase in LRI episodes and deaths was estimated among all adult age groups, with males aged 70 years and older having the highest increase in LRI episodes (126·0% [95% UI 121·4–131·1]) and deaths (100·0% [83·4–115·9]). During the same period, LRI episodes and deaths in children younger than 15 years were estimated to have decreased, and the greatest decline was observed for LRI deaths in males younger than 5 years (–70·7% [–77·2 to –61·8]). The leading risk factors for LRI mortality varied across age groups and sex. More than half of global LRI deaths in children younger than 5 years were attributable to child wasting (population attributable fraction [PAF] 53·0% [95% UI 37·7–61·8] in males and 56·4% [40·7–65·1] in females), and more than a quarter of LRI deaths among those aged 5–14 years were attributable to household air pollution (PAF 26·0% [95% UI 16·6–35·5] for males and PAF 25·8% [16·3–35·4] for females). PAFs of male LRI deaths attributed to smoking were 20·4% (95% UI 15·4–25·2) in those aged 15–49 years, 30·5% (24·1–36·9) in those aged 50–69 years, and 21·9% (16·8–27·3) in those aged 70 years and older. PAFs of female LRI deaths attributed to household air pollution were 21·1% (95% UI 14·5–27·9) in those aged 15–49 years and 18·2% (12·5–24·5) in those aged 50–69 years. For females aged 70 years and older, the leading risk factor, ambient particulate matter, was responsible for 11·7% (95% UI 8·2–15·8) of LRI deaths. Interpretation: The patterns and progress in reducing the burden of LRIs and key risk factors for mortality varied across age groups and sexes. The progress seen in children younger than 5 years was clearly a result of targeted interventions, such as vaccination and reduction of exposure to risk factors. Similar interventions for other age groups could contribute to the achievement of multiple Sustainable Development Goals targets, including promoting well eing at all ages and reducing health inequalities. Interventions, including addressing risk factors such as child wasting, smoking, ambient particulate matter pollution, and household air pollution, would prevent deaths and reduce health disparities. Funding: Bill & Melinda Gates Foundation. © 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license **Please note that there are multiple authors for this article therefore only the name of the first 30 including Federation University Australia affiliate “Muhammad Aziz Rahman and Huy Nguyen” is provided in this record**
Global, regional, and national burden of stroke and its risk factors, 1990-2019 : a systematic analysis for the Global Burden of Disease Study 2019
- Feigin, Valery, Stark, Benjamin, Johnson, Catherine, Roth, Gregory, Rahman, Muhammad Aziz
- Authors: Feigin, Valery , Stark, Benjamin , Johnson, Catherine , Roth, Gregory , Rahman, Muhammad Aziz
- Date: 2021
- Type: Text , Journal article
- Relation: The Lancet Neurology Vol. 20, no. 10 (2021), p. 1-26
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- Description: Background Regularly updated data on stroke and its pathological types, including data on their incidence, prevalence, mortality, disability, risk factors, and epidemiological trends, are important for evidence-based stroke care planning and resource allocation. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) aims to provide a standardised and comprehensive measurement of these metrics at global, regional, and national levels. Methods We applied GBD 2019 analytical tools to calculate stroke incidence, prevalence, mortality, disability-adjusted life-years (DALYs), and the population attributable fraction (PAF) of DALYs (with corresponding 95% uncertainty intervals [UIs]) associated with 19 risk factors, for 204 countries and territories from 1990 to 2019. These estimates were provided for ischaemic stroke, intracerebral haemorrhage, subarachnoid haemorrhage, and all strokes combined, and stratified by sex, age group, and World Bank country income level. Findings In 2019, there were 12·2 million (95% UI 11·0–13·6) incident cases of stroke, 101 million (93·2–111) prevalent cases of stroke, 143 million (133–153) DALYs due to stroke, and 6·55 million (6·00–7·02) deaths from stroke. Globally, stroke remained the second-leading cause of death (11·6% [10·8–12·2] of total deaths) and the third-leading cause of death and disability combined (5·7% [5·1–6·2] of total DALYs) in 2019. From 1990 to 2019, the absolute number of incident strokes increased by 70·0% (67·0–73·0), prevalent strokes increased by 85·0% (83·0–88·0), deaths from stroke increased by 43·0% (31·0–55·0), and DALYs due to stroke increased by 32·0% (22·0–42·0). During the same period, age-standardised rates of stroke incidence decreased by 17·0% (15·0–18·0), mortality decreased by 36·0% (31·0–42·0), prevalence decreased by 6·0% (5·0–7·0), and DALYs decreased by 36·0% (31·0–42·0). However, among people younger than 70 years, prevalence rates increased by 22·0% (21·0–24·0) and incidence rates increased by 15·0% (12·0–18·0). In 2019, the age-standardised stroke-related mortality rate was 3·6 (3·5–3·8) times higher in the World Bank low-income group than in the World Bank high-income group, and the age-standardised stroke-related DALY rate was 3·7 (3·5–3·9) times higher in the low-income group than the high-income group. Ischaemic stroke constituted 62·4% of all incident strokes in 2019 (7·63 million [6·57–8·96]), while intracerebral haemorrhage constituted 27·9% (3·41 million [2·97–3·91]) and subarachnoid haemorrhage constituted 9·7% (1·18 million [1·01–1·39]). In 2019, the five leading risk factors for stroke were high systolic blood pressure (contributing to 79·6 million [67·7–90·8] DALYs or 55·5% [48·2–62·0] of total stroke DALYs), high body-mass index (34·9 million [22·3–48·6] DALYs or 24·3% [15·7–33·2]), high fasting plasma glucose (28·9 million [19·8–41·5] DALYs or 20·2% [13·8–29·1]), ambient particulate matter pollution (28·7 million [23·4–33·4] DALYs or 20·1% [16·6–23·0]), and smoking (25·3 million [22·6–28·2] DALYs or 17·6% [16·4–19·0]). Interpretation The annual number of strokes and deaths due to stroke increased substantially from 1990 to 2019, despite substantial reductions in age-standardised rates, particularly among people older than 70 years. The highest age-standardised stroke-related mortality and DALY rates were in the World Bank low-income group. The fastest-growing risk factor for stroke between 1990 and 2019 was high body-mass index. Without urgent implementation of effective primary prevention strategies, the stroke burden will probably continue to grow across the world, particularly in low-income countries. © 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Muhammad Aziz Rahman” is provided in this record**
- Authors: Feigin, Valery , Stark, Benjamin , Johnson, Catherine , Roth, Gregory , Rahman, Muhammad Aziz
- Date: 2021
- Type: Text , Journal article
- Relation: The Lancet Neurology Vol. 20, no. 10 (2021), p. 1-26
- Full Text:
- Reviewed:
- Description: Background Regularly updated data on stroke and its pathological types, including data on their incidence, prevalence, mortality, disability, risk factors, and epidemiological trends, are important for evidence-based stroke care planning and resource allocation. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) aims to provide a standardised and comprehensive measurement of these metrics at global, regional, and national levels. Methods We applied GBD 2019 analytical tools to calculate stroke incidence, prevalence, mortality, disability-adjusted life-years (DALYs), and the population attributable fraction (PAF) of DALYs (with corresponding 95% uncertainty intervals [UIs]) associated with 19 risk factors, for 204 countries and territories from 1990 to 2019. These estimates were provided for ischaemic stroke, intracerebral haemorrhage, subarachnoid haemorrhage, and all strokes combined, and stratified by sex, age group, and World Bank country income level. Findings In 2019, there were 12·2 million (95% UI 11·0–13·6) incident cases of stroke, 101 million (93·2–111) prevalent cases of stroke, 143 million (133–153) DALYs due to stroke, and 6·55 million (6·00–7·02) deaths from stroke. Globally, stroke remained the second-leading cause of death (11·6% [10·8–12·2] of total deaths) and the third-leading cause of death and disability combined (5·7% [5·1–6·2] of total DALYs) in 2019. From 1990 to 2019, the absolute number of incident strokes increased by 70·0% (67·0–73·0), prevalent strokes increased by 85·0% (83·0–88·0), deaths from stroke increased by 43·0% (31·0–55·0), and DALYs due to stroke increased by 32·0% (22·0–42·0). During the same period, age-standardised rates of stroke incidence decreased by 17·0% (15·0–18·0), mortality decreased by 36·0% (31·0–42·0), prevalence decreased by 6·0% (5·0–7·0), and DALYs decreased by 36·0% (31·0–42·0). However, among people younger than 70 years, prevalence rates increased by 22·0% (21·0–24·0) and incidence rates increased by 15·0% (12·0–18·0). In 2019, the age-standardised stroke-related mortality rate was 3·6 (3·5–3·8) times higher in the World Bank low-income group than in the World Bank high-income group, and the age-standardised stroke-related DALY rate was 3·7 (3·5–3·9) times higher in the low-income group than the high-income group. Ischaemic stroke constituted 62·4% of all incident strokes in 2019 (7·63 million [6·57–8·96]), while intracerebral haemorrhage constituted 27·9% (3·41 million [2·97–3·91]) and subarachnoid haemorrhage constituted 9·7% (1·18 million [1·01–1·39]). In 2019, the five leading risk factors for stroke were high systolic blood pressure (contributing to 79·6 million [67·7–90·8] DALYs or 55·5% [48·2–62·0] of total stroke DALYs), high body-mass index (34·9 million [22·3–48·6] DALYs or 24·3% [15·7–33·2]), high fasting plasma glucose (28·9 million [19·8–41·5] DALYs or 20·2% [13·8–29·1]), ambient particulate matter pollution (28·7 million [23·4–33·4] DALYs or 20·1% [16·6–23·0]), and smoking (25·3 million [22·6–28·2] DALYs or 17·6% [16·4–19·0]). Interpretation The annual number of strokes and deaths due to stroke increased substantially from 1990 to 2019, despite substantial reductions in age-standardised rates, particularly among people older than 70 years. The highest age-standardised stroke-related mortality and DALY rates were in the World Bank low-income group. The fastest-growing risk factor for stroke between 1990 and 2019 was high body-mass index. Without urgent implementation of effective primary prevention strategies, the stroke burden will probably continue to grow across the world, particularly in low-income countries. © 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Muhammad Aziz Rahman” is provided in this record**
A fault-tolerant cascaded switched-capacitor multilevel inverter for domestic applications in smart grids
- Akbari, Ehsan, Teimouri, Ali, Saki, Mojtaba, Rezaei, Mohammad, Hu, Jiefeng, Band, Shahab, Pai, Hao-Ting, Mosavi, Amir
- Authors: Akbari, Ehsan , Teimouri, Ali , Saki, Mojtaba , Rezaei, Mohammad , Hu, Jiefeng , Band, Shahab , Pai, Hao-Ting , Mosavi, Amir
- Date: 2022
- Type: Text , Journal article
- Relation: IEEE Access Vol. 10, no. (2022), p. 110590-110602
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- Description: Cascaded multilevel inverters (MLIs) generate an output voltage using series-connected power modules that employ standard configurations of low-voltage components. Each module may employ one or more switched capacitors to double or quadruple its input voltage. The higher number of switched capacitors and semiconductor switches in MLIs compared to conventional two-level inverters has led to concerns about overall system reliability. A fault-tolerant design can mitigate this reliability issue. If one part of the system fails, the MLI can continue its planned operation at a reduced level rather than the entire system failing, which makes the fault tolerance of the MLI particularly important. In this paper, a novel fault location technique is presented that leads to a significant reduction in fault location detection time based on the reliability priority of the components of the proposed fault-tolerant switched capacitor cascaded MLI (CSCMLI). The main contribution of this paper is to reduce the number of MLI switches under fault conditions while operating at lower levels. The fault-tolerant inverter requires fewer switches at higher reliability, and the comparison with similar MLIs shows a faster dynamic response of fault detection and reduced fault location detection time. The experimental results confirm the effectiveness of the presented methods applied in the CSCMLI. Also, all experimental data including processor code, schematic, PCB, and video of CSCMLI operation are attached. © 2013 IEEE.
- Authors: Akbari, Ehsan , Teimouri, Ali , Saki, Mojtaba , Rezaei, Mohammad , Hu, Jiefeng , Band, Shahab , Pai, Hao-Ting , Mosavi, Amir
- Date: 2022
- Type: Text , Journal article
- Relation: IEEE Access Vol. 10, no. (2022), p. 110590-110602
- Full Text:
- Reviewed:
- Description: Cascaded multilevel inverters (MLIs) generate an output voltage using series-connected power modules that employ standard configurations of low-voltage components. Each module may employ one or more switched capacitors to double or quadruple its input voltage. The higher number of switched capacitors and semiconductor switches in MLIs compared to conventional two-level inverters has led to concerns about overall system reliability. A fault-tolerant design can mitigate this reliability issue. If one part of the system fails, the MLI can continue its planned operation at a reduced level rather than the entire system failing, which makes the fault tolerance of the MLI particularly important. In this paper, a novel fault location technique is presented that leads to a significant reduction in fault location detection time based on the reliability priority of the components of the proposed fault-tolerant switched capacitor cascaded MLI (CSCMLI). The main contribution of this paper is to reduce the number of MLI switches under fault conditions while operating at lower levels. The fault-tolerant inverter requires fewer switches at higher reliability, and the comparison with similar MLIs shows a faster dynamic response of fault detection and reduced fault location detection time. The experimental results confirm the effectiveness of the presented methods applied in the CSCMLI. Also, all experimental data including processor code, schematic, PCB, and video of CSCMLI operation are attached. © 2013 IEEE.
- Buykx, Penny, Kinsman, Leigh, Cooper, Simon J., McConnell-Henry, Tracy, Cant, Robyn, Endacott, Ruth
- Authors: Buykx, Penny , Kinsman, Leigh , Cooper, Simon J. , McConnell-Henry, Tracy , Cant, Robyn , Endacott, Ruth
- Date: 2011
- Type: Text , Journal article
- Relation: Nurse Education Today Vol. 31, no. 7 (2011), p. 687-693
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- Description: Delayed assessment and mismanagement of patient deterioration is a substantial problem for which educational preparation can have an impact. This paper describes the development of the FIRST2ACT simulation model based on well-established theory and contemporary empirical evidence. The model combines evidence-based elements of assessment, simulation, self-review and expert feedback, and has been tested in undergraduate nurses, student midwives and post-registration nurses. Participant evaluations indicated a high degree of satisfaction and substantial self-rated increases in knowledge, confidence and competence. This evidence-based model should be considered for both undergraduate and post-registration education programs.
The molecular epidemiology of influenza in Cambodia
- Authors: Suttie, Annika
- Date: 2019
- Type: Text , Thesis , PhD
- Full Text:
- Description: Avian influenza viruses (AIVs) represent a risk to the health of humans and animals. The prevalence of AIVs in live bird markets in Cambodia is among the highest in the world, being detected in 45.5% of tested poultry in 2015. To better understand the potential risk presented by AIVs, this thesis investigated the genetic characteristics of AIVs circulating in Cambodia between 2014 to 2018; focusing on subtypes that pose the greatest risk to human and animal health (H5, H7 and H9). Highly pathogenic (HP) H5N1 clade 2.3.2.1c viruses and low pathogenic H9N2 BJ/94-like h9-4.2.5 clade viruses were the most frequently detected subtypes, and circulate endemically in Cambodia’s domestic poultry. Co-infections were detected and facilitated the production of two novel reassortant H5N1 AIVs with single genes from H9N2 viruses. Additionally, numerous intrasubtypic reassortment events were detected for H5 and H9 AIVs. This is concerning as reassortment events can rapidly produce novel viruses of public health risk. Phylogenetic analyses showed some genes of the Cambodian H5, H7 and H9 AIVs clustered with zoonotic viruses, suggesting a common origin. There are parallels between H5N1 and H9N2 AIVs detected in Cambodia and Vietnam, likely facilitated through the illegal trade of live poultry and/or the migration of wild birds. Molecular analyses showed H9 AIVs have major markers associated with adaptation to mammals; though during the study period the only human AIV cases were the result of HP H5N1. Molecular markers of resistance to adamantine antivirals was observed in 3% of H5 and 41% of H9 AIVs; however, both subtypes remain susceptible to first line antiviral treatment, neuraminidase inhibitors. The data presented in this thesis demonstrates that circulation of Cambodian AIVs represents a risk for the emergence of novel viruses. Interventions are urgently needed to mitigate the threat posed to poultry and humans.
- Description: Doctor of Philosophy
- Authors: Suttie, Annika
- Date: 2019
- Type: Text , Thesis , PhD
- Full Text:
- Description: Avian influenza viruses (AIVs) represent a risk to the health of humans and animals. The prevalence of AIVs in live bird markets in Cambodia is among the highest in the world, being detected in 45.5% of tested poultry in 2015. To better understand the potential risk presented by AIVs, this thesis investigated the genetic characteristics of AIVs circulating in Cambodia between 2014 to 2018; focusing on subtypes that pose the greatest risk to human and animal health (H5, H7 and H9). Highly pathogenic (HP) H5N1 clade 2.3.2.1c viruses and low pathogenic H9N2 BJ/94-like h9-4.2.5 clade viruses were the most frequently detected subtypes, and circulate endemically in Cambodia’s domestic poultry. Co-infections were detected and facilitated the production of two novel reassortant H5N1 AIVs with single genes from H9N2 viruses. Additionally, numerous intrasubtypic reassortment events were detected for H5 and H9 AIVs. This is concerning as reassortment events can rapidly produce novel viruses of public health risk. Phylogenetic analyses showed some genes of the Cambodian H5, H7 and H9 AIVs clustered with zoonotic viruses, suggesting a common origin. There are parallels between H5N1 and H9N2 AIVs detected in Cambodia and Vietnam, likely facilitated through the illegal trade of live poultry and/or the migration of wild birds. Molecular analyses showed H9 AIVs have major markers associated with adaptation to mammals; though during the study period the only human AIV cases were the result of HP H5N1. Molecular markers of resistance to adamantine antivirals was observed in 3% of H5 and 41% of H9 AIVs; however, both subtypes remain susceptible to first line antiviral treatment, neuraminidase inhibitors. The data presented in this thesis demonstrates that circulation of Cambodian AIVs represents a risk for the emergence of novel viruses. Interventions are urgently needed to mitigate the threat posed to poultry and humans.
- Description: Doctor of Philosophy