Can optimum solar radiation exposure or supplemented vitamin D intake reduce the severity of COVID-19 symptoms?
- Abraham, Joji, Dowling, Kim, Florentine, Singarayer
- Authors: Abraham, Joji , Dowling, Kim , Florentine, Singarayer
- Date: 2021
- Type: Text , Journal article , Review
- Relation: International Journal of Environmental Research and Public Health Vol. 18, no. 2 (2021), p. 1-21
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- Description: The foremost mortality-causing symptom associated with COVID-19 is acute respiratory distress syndrome (ARDS). A significant correlation has been identified between the deficiency in vitamin D and the risk of developing ARDS. It has been suggested that if we can reduce or modify ARDS in COVID-19 patients, we may significantly reduce the severity of COVID-19 symptoms and associated mortality rates. The increased mortality of dark-skinned people, who have a reduced UV absorption capacity, may be consistent with diminished vitamin D status. The factors associated with COVID-19 mortality, such as old age, ethnicity, obesity, hypertension, cardiovascular diseases, and diabetes, are all found to be linked with vitamin D deficiency. Based on this review and as a precautionary measure, it is suggested that the adoption of appropriate and safe solar exposure and vitamin D enriched foods and supplements should be considered to reduce the possible severity of COVID-19 symptoms. Safe sun exposure is deemed beneficial globally, specifically in low and middle- income countries, as there is no cost involved. It is also noted that improved solar exposure and vitamin D levels can reduce the impact of other diseases as well, thus assisting in maintaining general human well-being. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
- Authors: Abraham, Joji , Dowling, Kim , Florentine, Singarayer
- Date: 2021
- Type: Text , Journal article , Review
- Relation: International Journal of Environmental Research and Public Health Vol. 18, no. 2 (2021), p. 1-21
- Full Text:
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- Description: The foremost mortality-causing symptom associated with COVID-19 is acute respiratory distress syndrome (ARDS). A significant correlation has been identified between the deficiency in vitamin D and the risk of developing ARDS. It has been suggested that if we can reduce or modify ARDS in COVID-19 patients, we may significantly reduce the severity of COVID-19 symptoms and associated mortality rates. The increased mortality of dark-skinned people, who have a reduced UV absorption capacity, may be consistent with diminished vitamin D status. The factors associated with COVID-19 mortality, such as old age, ethnicity, obesity, hypertension, cardiovascular diseases, and diabetes, are all found to be linked with vitamin D deficiency. Based on this review and as a precautionary measure, it is suggested that the adoption of appropriate and safe solar exposure and vitamin D enriched foods and supplements should be considered to reduce the possible severity of COVID-19 symptoms. Safe sun exposure is deemed beneficial globally, specifically in low and middle- income countries, as there is no cost involved. It is also noted that improved solar exposure and vitamin D levels can reduce the impact of other diseases as well, thus assisting in maintaining general human well-being. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Does climate play any role in covid-19 spreading? : an Australian perspective
- Abraham, Joji, Turville, Christopher, Dowling, Kim, Florentine, Singarayer
- Authors: Abraham, Joji , Turville, Christopher , Dowling, Kim , Florentine, Singarayer
- Date: 2021
- Type: Text , Journal article
- Relation: International Journal of Environmental Research and Public Health Vol. 18, no. 17 (2021), p.
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- Description: Compared to other countries, the COVID-19 pandemic did not severely affect Australia as measured by total deaths until mid-2021. Though a substantial number of daily confirmed cases (up to 698) were reported during the second wave, most of them were from the southern state of Victoria. This study examined the possible correlations between climate variables and the number of daily confirmed COVID-19 cases in Victoria, Australia, from 25 January to 31 October 2020. Appropriate regression models and cross-correlation diagnostics were used to examine the effect of temperature, rainfall, solar exposure, and ultraviolet index (UVI) with the number of daily confirmed cases. Significant positive associations were identified for solar exposure and maximum and average UVI for confirmed cases one and 19 days later. Negative associations for these variables were found for confirmed cases five days later. Minimum temperature had a significant negative correlation one day later and a positive effect 21 days later. No significant correlation was found for maximum temperature and rainfall. The most significant relationships were found for confirmed cases 19 days after changes in the meteorological variables. A 1% increase in solar exposure, maximum UVI, and average UVI was associated with a 0.31% (95% CI: 0.13 to 0.51), 0.71% (95% CI: 0.43 to 0.98), and 0.63% (95%CI: 0.20 to 1.61) increase 19 days later in the number of confirmed cases, respectively. The implications of these results can be used in the public health management of any possible future events in Australia. It also highlights the significance of considering the climatic variables and seasonality in all kinds of epidemics and pandemics. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
- Authors: Abraham, Joji , Turville, Christopher , Dowling, Kim , Florentine, Singarayer
- Date: 2021
- Type: Text , Journal article
- Relation: International Journal of Environmental Research and Public Health Vol. 18, no. 17 (2021), p.
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- Description: Compared to other countries, the COVID-19 pandemic did not severely affect Australia as measured by total deaths until mid-2021. Though a substantial number of daily confirmed cases (up to 698) were reported during the second wave, most of them were from the southern state of Victoria. This study examined the possible correlations between climate variables and the number of daily confirmed COVID-19 cases in Victoria, Australia, from 25 January to 31 October 2020. Appropriate regression models and cross-correlation diagnostics were used to examine the effect of temperature, rainfall, solar exposure, and ultraviolet index (UVI) with the number of daily confirmed cases. Significant positive associations were identified for solar exposure and maximum and average UVI for confirmed cases one and 19 days later. Negative associations for these variables were found for confirmed cases five days later. Minimum temperature had a significant negative correlation one day later and a positive effect 21 days later. No significant correlation was found for maximum temperature and rainfall. The most significant relationships were found for confirmed cases 19 days after changes in the meteorological variables. A 1% increase in solar exposure, maximum UVI, and average UVI was associated with a 0.31% (95% CI: 0.13 to 0.51), 0.71% (95% CI: 0.43 to 0.98), and 0.63% (95%CI: 0.20 to 1.61) increase 19 days later in the number of confirmed cases, respectively. The implications of these results can be used in the public health management of any possible future events in Australia. It also highlights the significance of considering the climatic variables and seasonality in all kinds of epidemics and pandemics. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
COVID-19 : psychological distress, fear, and coping strategies among community members across the United Arab Emirates
- Al Dweik, Rania, Rahman, Muhammad Aziz, Ahamed, Fathima, Ramada, Heba, Al Sheble, Yousef, ElTaher, Sondos, Cross, Wendy, Elsori, Deena
- Authors: Al Dweik, Rania , Rahman, Muhammad Aziz , Ahamed, Fathima , Ramada, Heba , Al Sheble, Yousef , ElTaher, Sondos , Cross, Wendy , Elsori, Deena
- Date: 2023
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 18, no. 3 March (2023), p.
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- Description: Background The COVID-19 pandemic impacted the psychosocial well-being of the United Arab Emirates [UAE] population like other communities internationally. Objectives We aimed to identify the factors associated with psychological distress, fear, and coping amongst community members across the UAE. Methods We conducted a cross-sectional online survey across the UAE during November 2020. Adults aged
- Authors: Al Dweik, Rania , Rahman, Muhammad Aziz , Ahamed, Fathima , Ramada, Heba , Al Sheble, Yousef , ElTaher, Sondos , Cross, Wendy , Elsori, Deena
- Date: 2023
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 18, no. 3 March (2023), p.
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- Description: Background The COVID-19 pandemic impacted the psychosocial well-being of the United Arab Emirates [UAE] population like other communities internationally. Objectives We aimed to identify the factors associated with psychological distress, fear, and coping amongst community members across the UAE. Methods We conducted a cross-sectional online survey across the UAE during November 2020. Adults aged
E-cigarette use among male smokers in Al-Ahsa, Kingdom of Saudi Arabia : a cross-sectional study
- Al Rajeh, Ahmed, Mahmud, Ilias, Al Imam, Mahmudul, Rahman, Muhammad Aziz, Al Shehri, Fariss, Alomayrin, Salman, Alfazae, Nawaf, Elmosaad, Yousif, Alasqah, Ibrahim
- Authors: Al Rajeh, Ahmed , Mahmud, Ilias , Al Imam, Mahmudul , Rahman, Muhammad Aziz , Al Shehri, Fariss , Alomayrin, Salman , Alfazae, Nawaf , Elmosaad, Yousif , Alasqah, Ibrahim
- Date: 2023
- Type: Text , Journal article
- Relation: International Journal of Environmental Research and Public Health Vol. 20, no. 1 (2023), p.
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- Description: E-cigarette use is increasing globally. Recent evidence suggests that e-cigarettes contain harmful substances that could cause adverse health outcomes. This study investigated the prevalence and associated factors of e-cigarette use among male current smokers in Saudi Arabia. We conducted a cross-sectional survey of adult male current smokers in the Al-Ahsa province of Saudi Arabia. Data were collected using a structured questionnaire. We performed logistic regression analyses to investigate the factors associated with e-cigarette use among adult male current smokers. 325 current smokers participated in the study. A third of them (33.5%) were e-cigarette users. Almost all the study participants (97.0%) had heard about e-cigarettes. Participants who were occasional smokers (Odds Ratio (OR): 2.28; 95% Confidence Interval (CI): 1.17–4.41) and had good knowledge perception of e-cigarettes (OR 3.49; 95% CI: 2.07–5.90) had higher odds of using e-cigarettes when compared to regular smokers of conventional cigarettes and current smokers with poor knowledge perception of e-cigarettes, respectively. In contrast, private employees (OR: 0.25, 95% CI: 0.07–0.85), and business owners (OR: 0.09, 95% CI: 0.01–0.63) had lower odds of using e-cigarettes compared to unemployed individuals. Compared with non-e-cigarette users, the rate of conventional cigarette smoking per day was significantly lower among e-cigarette users. Use of e-cigarette (OR: 3.57, 95% CI: 2.14–5.98), believing that e-cigarette quitting is hard (OR: 2.02, 95% CI: 1.17–3.49) and trying to quit e-cigarettes (OR: 2.17, 95% CI: 1.1–4.25) were found to be significant predictors of good knowledge perception of e-cigarettes among the current smokers. The use and knowledge perception of e-cigarettes were higher among occasional conventional male cigarette smokers than regular male smokers in Al-Ahsa province. The use of e-cigarettes as smoking cessation aids should be examined further in the Saudi Arabian setting. © 2022 by the authors.
- Authors: Al Rajeh, Ahmed , Mahmud, Ilias , Al Imam, Mahmudul , Rahman, Muhammad Aziz , Al Shehri, Fariss , Alomayrin, Salman , Alfazae, Nawaf , Elmosaad, Yousif , Alasqah, Ibrahim
- Date: 2023
- Type: Text , Journal article
- Relation: International Journal of Environmental Research and Public Health Vol. 20, no. 1 (2023), p.
- Full Text:
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- Description: E-cigarette use is increasing globally. Recent evidence suggests that e-cigarettes contain harmful substances that could cause adverse health outcomes. This study investigated the prevalence and associated factors of e-cigarette use among male current smokers in Saudi Arabia. We conducted a cross-sectional survey of adult male current smokers in the Al-Ahsa province of Saudi Arabia. Data were collected using a structured questionnaire. We performed logistic regression analyses to investigate the factors associated with e-cigarette use among adult male current smokers. 325 current smokers participated in the study. A third of them (33.5%) were e-cigarette users. Almost all the study participants (97.0%) had heard about e-cigarettes. Participants who were occasional smokers (Odds Ratio (OR): 2.28; 95% Confidence Interval (CI): 1.17–4.41) and had good knowledge perception of e-cigarettes (OR 3.49; 95% CI: 2.07–5.90) had higher odds of using e-cigarettes when compared to regular smokers of conventional cigarettes and current smokers with poor knowledge perception of e-cigarettes, respectively. In contrast, private employees (OR: 0.25, 95% CI: 0.07–0.85), and business owners (OR: 0.09, 95% CI: 0.01–0.63) had lower odds of using e-cigarettes compared to unemployed individuals. Compared with non-e-cigarette users, the rate of conventional cigarette smoking per day was significantly lower among e-cigarette users. Use of e-cigarette (OR: 3.57, 95% CI: 2.14–5.98), believing that e-cigarette quitting is hard (OR: 2.02, 95% CI: 1.17–3.49) and trying to quit e-cigarettes (OR: 2.17, 95% CI: 1.1–4.25) were found to be significant predictors of good knowledge perception of e-cigarettes among the current smokers. The use and knowledge perception of e-cigarettes were higher among occasional conventional male cigarette smokers than regular male smokers in Al-Ahsa province. The use of e-cigarettes as smoking cessation aids should be examined further in the Saudi Arabian setting. © 2022 by the authors.
The experiences of people with diabetes during covid-19 pandemic lockdown
- Al-Moteri, Modi, Plummer, Virginia, Youssef, Hanan, Yaseen, Ruba, Al Malki, Mohammed, Elryah, Ahmed, Al Karani, Ahmed
- Authors: Al-Moteri, Modi , Plummer, Virginia , Youssef, Hanan , Yaseen, Ruba , Al Malki, Mohammed , Elryah, Ahmed , Al Karani, Ahmed
- Date: 2022
- Type: Text , Journal article
- Relation: International Journal of Environmental Research and Public Health Vol. 19, no. 1 (2022), p.
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- Description: Little is known about the theoretical foundation underling the response of people with diabetes managing their everyday routines during COVID-19 pandemic lockdown. Aim: To explore the experience of people with diabetes during COVID-19 pandemic lockdown in light of the risk perception, response and behavioral change theories. Method: A qualitative descriptive design was employed, and Braun and Clark’s six step analysis were used for thematic analysis. Semi-structured interviews were conducted online using Zoom Videos Communication. Result: Five themes were defined as follows: (1) perceived the threat and faced their fears, (2) appraised the damage, (3) identified the challenges, (4) modified their routine, and (5) identified the strengths that facilitate the efficacy of their response. There were eight sub-themes within the themes. Conclusion: The results of this study may provide an opportunity for nurses to reflect on issues highlighted by the patients regarding more effective communication, knowledge and skill development for people to support self-care during national emergencies. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
- Authors: Al-Moteri, Modi , Plummer, Virginia , Youssef, Hanan , Yaseen, Ruba , Al Malki, Mohammed , Elryah, Ahmed , Al Karani, Ahmed
- Date: 2022
- Type: Text , Journal article
- Relation: International Journal of Environmental Research and Public Health Vol. 19, no. 1 (2022), p.
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- Description: Little is known about the theoretical foundation underling the response of people with diabetes managing their everyday routines during COVID-19 pandemic lockdown. Aim: To explore the experience of people with diabetes during COVID-19 pandemic lockdown in light of the risk perception, response and behavioral change theories. Method: A qualitative descriptive design was employed, and Braun and Clark’s six step analysis were used for thematic analysis. Semi-structured interviews were conducted online using Zoom Videos Communication. Result: Five themes were defined as follows: (1) perceived the threat and faced their fears, (2) appraised the damage, (3) identified the challenges, (4) modified their routine, and (5) identified the strengths that facilitate the efficacy of their response. There were eight sub-themes within the themes. Conclusion: The results of this study may provide an opportunity for nurses to reflect on issues highlighted by the patients regarding more effective communication, knowledge and skill development for people to support self-care during national emergencies. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Roles of selective agriculture practices in sustainable agricultural performance : a systematic review
- Ali, Basharat, Dahlhaus, Peter
- Authors: Ali, Basharat , Dahlhaus, Peter
- Date: 2022
- Type: Text , Journal article , Review
- Relation: Sustainability (Switzerland) Vol. 14, no. 6 (2022), p.
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- Description: Feeding the growing global population while improving the Earth’s economic, environmental, and social values is a challenge recognised in both the United Nations Sustainable Development Goals and the United Nations Framework Convention on Climate Change. Sustaining global agricultural performance requires regular revision of current farming models, attitudes, and practices. In systematically reviewing the international literature through the lens of the sustainability framework, this paper specifically identifies precision conservation agriculture (PCA), digital agriculture (DA), and resilient agriculture (RA) practices as being of value in meeting future challenges. Each of these adaptations carries significantly positive relationships with sustaining agricultural performance, as well as positively mediating and/or moderating each other. While it is clear from the literature that adopting PCA, DA, and RA would substantially improve the sustainability of agricultural performance, the uptake of these adaptations generally lags. More in-depth social science research is required to understand the value propositions that would encourage uptake of these adaptations and the barriers that prevent them. Recommendations are made to explore the specific knowledge gap that needs to be understood to motivate agriculture practitioners to adopt these changes in practice. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
- Authors: Ali, Basharat , Dahlhaus, Peter
- Date: 2022
- Type: Text , Journal article , Review
- Relation: Sustainability (Switzerland) Vol. 14, no. 6 (2022), p.
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- Description: Feeding the growing global population while improving the Earth’s economic, environmental, and social values is a challenge recognised in both the United Nations Sustainable Development Goals and the United Nations Framework Convention on Climate Change. Sustaining global agricultural performance requires regular revision of current farming models, attitudes, and practices. In systematically reviewing the international literature through the lens of the sustainability framework, this paper specifically identifies precision conservation agriculture (PCA), digital agriculture (DA), and resilient agriculture (RA) practices as being of value in meeting future challenges. Each of these adaptations carries significantly positive relationships with sustaining agricultural performance, as well as positively mediating and/or moderating each other. While it is clear from the literature that adopting PCA, DA, and RA would substantially improve the sustainability of agricultural performance, the uptake of these adaptations generally lags. More in-depth social science research is required to understand the value propositions that would encourage uptake of these adaptations and the barriers that prevent them. Recommendations are made to explore the specific knowledge gap that needs to be understood to motivate agriculture practitioners to adopt these changes in practice. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
Mineral texture identification using local binary patterns equipped with a Classification and Recognition Updating System (CARUS)
- Aligholi, Saeed, Khajavi, Reza, Khandelwal, Manoj, Armaghani, Danial
- Authors: Aligholi, Saeed , Khajavi, Reza , Khandelwal, Manoj , Armaghani, Danial
- Date: 2022
- Type: Text , Journal article
- Relation: Sustainability (Switzerland) Vol. 14, no. 18 (2022), p.
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- Description: In this paper, a rotation-invariant local binary pattern operator equipped with a local contrast measure (riLBPc) is employed to characterize the type of mineral twinning by inspecting the texture properties of crystals. The proposed method uses photomicrographs of minerals and produces LBP histograms, which might be compared with those included in a predefined database using the Kullback–Leibler divergence-based metric. The paper proposes a new LBP-based scheme for concurrent classification and recognition tasks, followed by a novel online updating routine to enhance the locally developed mineral LBP database. The discriminatory power of the proposed Classification and Recognition Updating System (CARUS) for texture identification scheme is verified for plagioclase, orthoclase, microcline, and quartz minerals with sensitivity (TPR) near 99.9%, 87%, 99.9%, and 96%, and accuracy (ACC) equal to about 99%, 97%, 99%, and 99%, respectively. According to the results, the introduced CARUS system is a promising approach that can be applied in a variety of different fields dealing with classification and feature recognition tasks. © 2022 by the authors.
- Authors: Aligholi, Saeed , Khajavi, Reza , Khandelwal, Manoj , Armaghani, Danial
- Date: 2022
- Type: Text , Journal article
- Relation: Sustainability (Switzerland) Vol. 14, no. 18 (2022), p.
- Full Text:
- Reviewed:
- Description: In this paper, a rotation-invariant local binary pattern operator equipped with a local contrast measure (riLBPc) is employed to characterize the type of mineral twinning by inspecting the texture properties of crystals. The proposed method uses photomicrographs of minerals and produces LBP histograms, which might be compared with those included in a predefined database using the Kullback–Leibler divergence-based metric. The paper proposes a new LBP-based scheme for concurrent classification and recognition tasks, followed by a novel online updating routine to enhance the locally developed mineral LBP database. The discriminatory power of the proposed Classification and Recognition Updating System (CARUS) for texture identification scheme is verified for plagioclase, orthoclase, microcline, and quartz minerals with sensitivity (TPR) near 99.9%, 87%, 99.9%, and 96%, and accuracy (ACC) equal to about 99%, 97%, 99%, and 99%, respectively. According to the results, the introduced CARUS system is a promising approach that can be applied in a variety of different fields dealing with classification and feature recognition tasks. © 2022 by the authors.
Intermittency of rock fractured surfaces : a power law
- Aligholi, Saeed, Khandelwal, Manoj
- Authors: Aligholi, Saeed , Khandelwal, Manoj
- Date: 2022
- Type: Text , Journal article
- Relation: Water (Switzerland) Vol. 14, no. 22 (2022), p.
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- Description: Roughness of rock fractured surfaces is one of the most important factors controlling fluid flow in rock masses. Roughness quantification is of prime importance for modelling the flow of ground waters as well as reservoir fluid mechanics. In this study, with the aid of high-resolution 3D X-ray CT scanning and image processing techniques, the roughness of four different rock types is reconstructed with a resolution of 16.5 microns. Moreover, the correlation and structure functions are used to analyse height fluctuations as well as statistical intermittency of the studied rock fractured surfaces. It is observed that at length scales smaller than a critical length scale, fractures surfaces are correlated and show multifractality. Monofractals are neither intermittent nor correlated; hence, a meaningful link between statistical intermittency and the correlation function of multifractals is expected. However, a model that considers this relationship and predicts multifractal spectra of disordered systems is still missing. A simple power law that can exactly forecast the multiscaling spectrum of rock fracture process zone is being introduced. It is explained how the exponent of this power function
- Authors: Aligholi, Saeed , Khandelwal, Manoj
- Date: 2022
- Type: Text , Journal article
- Relation: Water (Switzerland) Vol. 14, no. 22 (2022), p.
- Full Text:
- Reviewed:
- Description: Roughness of rock fractured surfaces is one of the most important factors controlling fluid flow in rock masses. Roughness quantification is of prime importance for modelling the flow of ground waters as well as reservoir fluid mechanics. In this study, with the aid of high-resolution 3D X-ray CT scanning and image processing techniques, the roughness of four different rock types is reconstructed with a resolution of 16.5 microns. Moreover, the correlation and structure functions are used to analyse height fluctuations as well as statistical intermittency of the studied rock fractured surfaces. It is observed that at length scales smaller than a critical length scale, fractures surfaces are correlated and show multifractality. Monofractals are neither intermittent nor correlated; hence, a meaningful link between statistical intermittency and the correlation function of multifractals is expected. However, a model that considers this relationship and predicts multifractal spectra of disordered systems is still missing. A simple power law that can exactly forecast the multiscaling spectrum of rock fracture process zone is being introduced. It is explained how the exponent of this power function
Order of intermittent rock fractured surfaces
- Aligholi, Saeed, Khandelwal, Manoj
- Authors: Aligholi, Saeed , Khandelwal, Manoj
- Date: 2023
- Type: Text , Journal article
- Relation: Sustainability (Switzerland) Vol. 15, no. 1 (2023), p.
- Full Text:
- Reviewed:
- Description: According to chaos theory, some underlying patterns can disclose the order of disordered systems. Here, it has been discussed that intermittency of rough rock fractured surfaces is an orderable disorder at intermediate length scales. However, this kind of disorder is more complicated than simple fractal or even multi-scaling behaviours. It is planned to deal with some multifractal spectra that systematically change as a function of the analysed domain. Accordingly, some parameters are introduced that can perfectly take into account such systematic behaviour and quantify the intermittency of the studied surfaces. This framework can be used to quantify and model the roughness of fractured surfaces as a prerequisite factor for the analysis of fluid flow in rock media as well as the shear strength of rock joints. Ultimately, the presented framework can be used for analysing the intermittency of time series and developing new models for predicting, for instance, seismic or flood events in a short time with higher accuracy. © 2022 by the authors.
- Authors: Aligholi, Saeed , Khandelwal, Manoj
- Date: 2023
- Type: Text , Journal article
- Relation: Sustainability (Switzerland) Vol. 15, no. 1 (2023), p.
- Full Text:
- Reviewed:
- Description: According to chaos theory, some underlying patterns can disclose the order of disordered systems. Here, it has been discussed that intermittency of rough rock fractured surfaces is an orderable disorder at intermediate length scales. However, this kind of disorder is more complicated than simple fractal or even multi-scaling behaviours. It is planned to deal with some multifractal spectra that systematically change as a function of the analysed domain. Accordingly, some parameters are introduced that can perfectly take into account such systematic behaviour and quantify the intermittency of the studied surfaces. This framework can be used to quantify and model the roughness of fractured surfaces as a prerequisite factor for the analysis of fluid flow in rock media as well as the shear strength of rock joints. Ultimately, the presented framework can be used for analysing the intermittency of time series and developing new models for predicting, for instance, seismic or flood events in a short time with higher accuracy. © 2022 by the authors.
Association between nocturnal activity of the sympathetic nervous system and cognitive dysfunction in obstructive sleep apnoea
- Alomri, Ridwan, Kennedy, Gerard, Wali, Siraj, Alhejaili, Faris, Robinson, Stephen
- Authors: Alomri, Ridwan , Kennedy, Gerard , Wali, Siraj , Alhejaili, Faris , Robinson, Stephen
- Date: 2021
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 11, no. 1 (2021), p. 11990-11990.
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- Description: Obstructive sleep apnoea (OSA) is associated with repetitive breathing obstructions during sleep. These episodes of hypoxia and associated arousals from sleep induce physiological stress and nocturnal over-activation of the sympathetic nervous system (SNS). One consequence of OSA is impairment in a range of cognitive domains. Previous research into cognitive impairment in OSA have focussed on intermittent hypoxia and disrupted sleep, but not nocturnal over-activation of the SNS. Therefore, we investigated whether nocturnal over-activity of the SNS was associated with cognitive impairments in OSA. The extent of nocturnal SNS activation was estimated from heart rate variability (HRV), pulse wave amplitude (PWA) and stress response biomarkers (cortisol and glucose levels). OSA severity was significantly associated with PWA indices and the HRV low frequency/ high frequency ratio (p < 0.05). Morning blood glucose levels were significantly associated with the duration of a blood oxygen saturation (SaO2) < 90% (p < 0.01). PWA and HRV were significantly associated with the time taken to perform a task involving visuospatial functioning (p < 0.05), but not with impairments in sustained attention, reaction time or autobiographical memory. These results suggest that the visuospatial dysfunction observed in people with OSA is associated with increased nocturnal activity of the SNS. © 2021, The Author(s).
- Authors: Alomri, Ridwan , Kennedy, Gerard , Wali, Siraj , Alhejaili, Faris , Robinson, Stephen
- Date: 2021
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 11, no. 1 (2021), p. 11990-11990.
- Full Text:
- Reviewed:
- Description: Obstructive sleep apnoea (OSA) is associated with repetitive breathing obstructions during sleep. These episodes of hypoxia and associated arousals from sleep induce physiological stress and nocturnal over-activation of the sympathetic nervous system (SNS). One consequence of OSA is impairment in a range of cognitive domains. Previous research into cognitive impairment in OSA have focussed on intermittent hypoxia and disrupted sleep, but not nocturnal over-activation of the SNS. Therefore, we investigated whether nocturnal over-activity of the SNS was associated with cognitive impairments in OSA. The extent of nocturnal SNS activation was estimated from heart rate variability (HRV), pulse wave amplitude (PWA) and stress response biomarkers (cortisol and glucose levels). OSA severity was significantly associated with PWA indices and the HRV low frequency/ high frequency ratio (p < 0.05). Morning blood glucose levels were significantly associated with the duration of a blood oxygen saturation (SaO2) < 90% (p < 0.01). PWA and HRV were significantly associated with the time taken to perform a task involving visuospatial functioning (p < 0.05), but not with impairments in sustained attention, reaction time or autobiographical memory. These results suggest that the visuospatial dysfunction observed in people with OSA is associated with increased nocturnal activity of the SNS. © 2021, The Author(s).
Evidence of subdivisions on evolutionary timescales in a large, declining marsupial distributed across a phylogeographic barrier
- Alpers, Deryn, Walker, Faith, Taylor, Andrea, Sunnucks, Paul, Bellman, Steven, Hansen, Birgita, Sherwin, William
- Authors: Alpers, Deryn , Walker, Faith , Taylor, Andrea , Sunnucks, Paul , Bellman, Steven , Hansen, Birgita , Sherwin, William
- Date: 2016
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 11, no. 10 (2016), p. 1-22
- Full Text:
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- Description: Major prehistoric forces, such as the climatic shifts of the Pleistocene, can remain visible in a species' population genetics. Inference of refuges via genetic tools is useful for conservation management as it can identify populations whose preservation may help retain a species' adaptive potential. Such investigation is needed for Australia's southern hairy-nosed wombat (Lasiorhinus latifrons), whose conservation status has recently deteriorated, and whose phylogeographic history during the Pleistocene may be atypical compared to other species. Its contemporary range spans approximately 2000 km of diverse habitat on either side of the Spencer Gulf, which was a land bridge during periods of Pleistocene aridity that may have allowed for migration circumventing the arid Eyrean barrier. We sampled from animals in nearly all known sites within the species' current distribution, mainly using non-invasive methods, and employed nuclear and mitochondrial DNA analyses to assess alternative scenarios for Pleistocene impacts on population structure. We found evidence for mildly differentiated populations at the range extremes on either side of Spencer Gulf, with secondary contact between locations neighbouring each side of the barrier. These extreme western and eastern regions, and four other regions in between, were genetically distinct in genotypic clustering analyses. Estimates indicate modest, but complex gene flow patterns among some of these regions, in some cases possibly restricted for several thousand years. Prior to this study there was little information to aid risk assessment and prioritization of conservation interventions facilitating gene flow among populations of this species. The contributions of this study to that issue are outlined. © 2016 Alpers et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
- Authors: Alpers, Deryn , Walker, Faith , Taylor, Andrea , Sunnucks, Paul , Bellman, Steven , Hansen, Birgita , Sherwin, William
- Date: 2016
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 11, no. 10 (2016), p. 1-22
- Full Text:
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- Description: Major prehistoric forces, such as the climatic shifts of the Pleistocene, can remain visible in a species' population genetics. Inference of refuges via genetic tools is useful for conservation management as it can identify populations whose preservation may help retain a species' adaptive potential. Such investigation is needed for Australia's southern hairy-nosed wombat (Lasiorhinus latifrons), whose conservation status has recently deteriorated, and whose phylogeographic history during the Pleistocene may be atypical compared to other species. Its contemporary range spans approximately 2000 km of diverse habitat on either side of the Spencer Gulf, which was a land bridge during periods of Pleistocene aridity that may have allowed for migration circumventing the arid Eyrean barrier. We sampled from animals in nearly all known sites within the species' current distribution, mainly using non-invasive methods, and employed nuclear and mitochondrial DNA analyses to assess alternative scenarios for Pleistocene impacts on population structure. We found evidence for mildly differentiated populations at the range extremes on either side of Spencer Gulf, with secondary contact between locations neighbouring each side of the barrier. These extreme western and eastern regions, and four other regions in between, were genetically distinct in genotypic clustering analyses. Estimates indicate modest, but complex gene flow patterns among some of these regions, in some cases possibly restricted for several thousand years. Prior to this study there was little information to aid risk assessment and prioritization of conservation interventions facilitating gene flow among populations of this species. The contributions of this study to that issue are outlined. © 2016 Alpers et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Duration of intervals in the care seeking pathway for lung cancer in Bangladesh : a journey from symptoms triggering consultation to receipt of treatment
- Ansar, Adnan, Lewis, Virginia, McDonald, Christine, Liu, , Chaojie, Rahman, Muhammad Aziz
- Authors: Ansar, Adnan , Lewis, Virginia , McDonald, Christine , Liu, , Chaojie , Rahman, Muhammad Aziz
- Date: 2021
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 16, no. 9 September (2021), p.
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- Description: Timeliness in seeking care is critical for lung cancer patients survival and better prognosis. The care seeking trajectory of patients with lung cancer in Bangladesh has not been explored, despite the differences in health systems and structures compared to high income countries. This study investigated the symptoms triggering healthcare seeking, preferred healthcare providers (including informal healthcare providers such as pharmacy retailers, village doctors, and "traditional healers"), and the duration of intervals in the lung cancer care pathway of patients in Bangladesh. A cross-sectional study was conducted in three tertiary care hospitals in Bangladesh among diagnosed lung cancer patients through face-Toface interview and medical record review. Time intervals from onset of symptom and care seeking events were calculated and compared between those who sought initial care from different providers using Wilcoxon rank sum tests. Among 418 study participants, the majority (90%) of whom were males, with a mean age of 57 ±9.86 years, cough and chest pain were the most common (23%) combination of symptoms triggering healthcare seeking. About two-Thirds of the total respondents (60%) went to informal healthcare providers as their first point of contact. Living in rural areas, lower levels of education and lower income were associated with seeking care from such providers. The median duration between onset of symptom to confirmation of diagnosis was 121 days, between confirmation of diagnosis and initiation of treatment was 22 days, and between onset of symptom and initiation of treatment was 151 days. Pre-diagnosis durations were longer for those who had sought initial care from an informal provider (p<0.05). Time to first contact with a health provider was shorter in this study compared to other developed and developing countries but utilizing informal healthcare providers caused delays in diagnosis and initiation of treatment. Encouraging people to seek care from a formal healthcare provider may reduce the overall duration of the care seeking pathway. © 2021 Public Library of Science. All rights reserved.
- Authors: Ansar, Adnan , Lewis, Virginia , McDonald, Christine , Liu, , Chaojie , Rahman, Muhammad Aziz
- Date: 2021
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 16, no. 9 September (2021), p.
- Full Text:
- Reviewed:
- Description: Timeliness in seeking care is critical for lung cancer patients survival and better prognosis. The care seeking trajectory of patients with lung cancer in Bangladesh has not been explored, despite the differences in health systems and structures compared to high income countries. This study investigated the symptoms triggering healthcare seeking, preferred healthcare providers (including informal healthcare providers such as pharmacy retailers, village doctors, and "traditional healers"), and the duration of intervals in the lung cancer care pathway of patients in Bangladesh. A cross-sectional study was conducted in three tertiary care hospitals in Bangladesh among diagnosed lung cancer patients through face-Toface interview and medical record review. Time intervals from onset of symptom and care seeking events were calculated and compared between those who sought initial care from different providers using Wilcoxon rank sum tests. Among 418 study participants, the majority (90%) of whom were males, with a mean age of 57 ±9.86 years, cough and chest pain were the most common (23%) combination of symptoms triggering healthcare seeking. About two-Thirds of the total respondents (60%) went to informal healthcare providers as their first point of contact. Living in rural areas, lower levels of education and lower income were associated with seeking care from such providers. The median duration between onset of symptom to confirmation of diagnosis was 121 days, between confirmation of diagnosis and initiation of treatment was 22 days, and between onset of symptom and initiation of treatment was 151 days. Pre-diagnosis durations were longer for those who had sought initial care from an informal provider (p<0.05). Time to first contact with a health provider was shorter in this study compared to other developed and developing countries but utilizing informal healthcare providers caused delays in diagnosis and initiation of treatment. Encouraging people to seek care from a formal healthcare provider may reduce the overall duration of the care seeking pathway. © 2021 Public Library of Science. All rights reserved.
Prediction of blast-induced ground vibration at a limestone quarry : an artificial intelligence approach
- Arthur, Clement, Bhatawdekar, Ramesh, Mohamad, Edy, Sabri, Mohanad, Bohra, Manish, Khandelwal, Manoj, Kwon, Sangki
- Authors: Arthur, Clement , Bhatawdekar, Ramesh , Mohamad, Edy , Sabri, Mohanad , Bohra, Manish , Khandelwal, Manoj , Kwon, Sangki
- Date: 2022
- Type: Text , Journal article
- Relation: Applied Sciences (Switzerland) Vol. 12, no. 18 (2022), p.
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- Description: Ground vibration is one of the most unfavourable environmental effects of blasting activities, which can cause serious damage to neighboring homes and structures. As a result, effective forecasting of their severity is critical to controlling and reducing their recurrence. There are several conventional vibration predictor equations available proposed by different researchers but most of them are based on only two parameters, i.e., explosive charge used per delay and distance between blast face to the monitoring point. It is a well-known fact that blasting results are influenced by a number of blast design parameters, such as burden, spacing, powder factor, etc. but these are not being considered in any of the available conventional predictors and due to that they show a high error in predicting blast vibrations. Nowadays, artificial intelligence has been widely used in blast engineering. Thus, three artificial intelligence approaches, namely Gaussian process regression (GPR), extreme learning machine (ELM) and backpropagation neural network (BPNN) were used in this study to estimate ground vibration caused by blasting in Shree Cement Ras Limestone Mine in India. To achieve that aim, 101 blasting datasets with powder factor, average depth, distance, spacing, burden, charge weight, and stemming length as input parameters were collected from the mine site. For comparison purposes, a simple multivariate regression analysis (MVRA) model as well as, a nonparametric regression-based technique known as multivariate adaptive regression splines (MARS) was also constructed using the same datasets. This study serves as a foundational study for the comparison of GPR, BPNN, ELM, MARS and MVRA to ascertain their respective predictive performances. Eighty-one (81) datasets representing 80% of the total blasting datasets were used to construct and train the various predictive models while 20 data samples (20%) were utilized for evaluating the predictive capabilities of the developed predictive models. Using the testing datasets, major indicators of performance, namely mean squared error (MSE), variance accounted for (VAF), correlation coefficient (R) and coefficient of determination (R2) were compared as statistical evaluators of model performance. This study revealed that the GPR model exhibited superior predictive capability in comparison to the MARS, BPNN, ELM and MVRA. The GPR model showed the highest VAF, R and R2 values of 99.1728%, 0.9985 and 0.9971 respectively and the lowest MSE of 0.0903. As a result, the blast engineer can employ GPR as an effective and appropriate method for forecasting blast-induced ground vibration. © 2022 by the authors.
- Authors: Arthur, Clement , Bhatawdekar, Ramesh , Mohamad, Edy , Sabri, Mohanad , Bohra, Manish , Khandelwal, Manoj , Kwon, Sangki
- Date: 2022
- Type: Text , Journal article
- Relation: Applied Sciences (Switzerland) Vol. 12, no. 18 (2022), p.
- Full Text:
- Reviewed:
- Description: Ground vibration is one of the most unfavourable environmental effects of blasting activities, which can cause serious damage to neighboring homes and structures. As a result, effective forecasting of their severity is critical to controlling and reducing their recurrence. There are several conventional vibration predictor equations available proposed by different researchers but most of them are based on only two parameters, i.e., explosive charge used per delay and distance between blast face to the monitoring point. It is a well-known fact that blasting results are influenced by a number of blast design parameters, such as burden, spacing, powder factor, etc. but these are not being considered in any of the available conventional predictors and due to that they show a high error in predicting blast vibrations. Nowadays, artificial intelligence has been widely used in blast engineering. Thus, three artificial intelligence approaches, namely Gaussian process regression (GPR), extreme learning machine (ELM) and backpropagation neural network (BPNN) were used in this study to estimate ground vibration caused by blasting in Shree Cement Ras Limestone Mine in India. To achieve that aim, 101 blasting datasets with powder factor, average depth, distance, spacing, burden, charge weight, and stemming length as input parameters were collected from the mine site. For comparison purposes, a simple multivariate regression analysis (MVRA) model as well as, a nonparametric regression-based technique known as multivariate adaptive regression splines (MARS) was also constructed using the same datasets. This study serves as a foundational study for the comparison of GPR, BPNN, ELM, MARS and MVRA to ascertain their respective predictive performances. Eighty-one (81) datasets representing 80% of the total blasting datasets were used to construct and train the various predictive models while 20 data samples (20%) were utilized for evaluating the predictive capabilities of the developed predictive models. Using the testing datasets, major indicators of performance, namely mean squared error (MSE), variance accounted for (VAF), correlation coefficient (R) and coefficient of determination (R2) were compared as statistical evaluators of model performance. This study revealed that the GPR model exhibited superior predictive capability in comparison to the MARS, BPNN, ELM and MVRA. The GPR model showed the highest VAF, R and R2 values of 99.1728%, 0.9985 and 0.9971 respectively and the lowest MSE of 0.0903. As a result, the blast engineer can employ GPR as an effective and appropriate method for forecasting blast-induced ground vibration. © 2022 by the authors.
Prevalence of and factors associated with anaemia in women of reproductive age in Bangladesh, Maldives and Nepal : evidence from nationally-representative survey data
- Ashfikur Rahman, Md, Sazedur Rahman, Md, Rahman, Muhammad Aziz, Szymlek-Gay, Ewa, Uddin, Riaz, Islam, Sheikh
- Authors: Ashfikur Rahman, Md , Sazedur Rahman, Md , Rahman, Muhammad Aziz , Szymlek-Gay, Ewa , Uddin, Riaz , Islam, Sheikh
- Date: 2021
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 16, no. 1 January (2021), p.
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- Description: Background Anaemia is a significant public health problem in most South-Asian countries, causing increased maternal and child mortality and morbidity. This study aimed to estimate the prevalence of and factors associated with anaemia in women of reproductive age in Bangladesh, Maldives, and Nepal. Methods We used the nationally-representative Demographic and Health Surveys Program data collected from women of reproductive age (15-49 years) in 2011 in Bangladesh (n = 5678), 2016 in Maldives (n = 6837), and 2016 in Nepal (n = 6419). Anaemia was categorized as mild (haemoglobin [Hb] of 10.0-10.9 g/dL for pregnant women and 11.0-11.9 g/dL for non-pregnant women), moderate (Hb of 7.0-9.9 g/dL for pregnant women and 8.0-10.9 g/dL for non-pregnant women), and severe (Hb <7.0 g/dL for pregnant women and <8.0 g/dL for non-pregnant women). Multinomial logistic regression analyses were used to identify factors associated with anaemia. Results The prevalence of anaemia was 41.8% in Bangladesh, 58.5% in Maldives, and 40.6% in Nepal. In Bangladesh, postpartum amenorrhoeic, non-educated, and pregnant women were more likely to have moderate/severe anaemia compared to women who were menopausal, had secondary education, and were not pregnant, respectively. In Maldives, residence in urban areas, underweight, having undergone female sterilization, current pregnancy, and menstruation in the last six weeks were associated with increased odds of moderate/severe anaemia. In Nepal, factors associated with increased odds of moderate/ severe anaemia were having undergone female sterilization and current pregnancy. Conclusion Anaemia remains a significant public health issue among 15-49-year-old women in Bangladesh, Maldives, and Nepal, which requires urgent attention. Effective policies and programmes for the control and prevention of anaemia should take into account the unique factors associated with anaemia identified in each country. In all three countries, strategies for the prevention and control of anaemia should particularly focus on women who are pregnant, underweight, or have undergone sterilization. © 2021 Rahman et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
- Authors: Ashfikur Rahman, Md , Sazedur Rahman, Md , Rahman, Muhammad Aziz , Szymlek-Gay, Ewa , Uddin, Riaz , Islam, Sheikh
- Date: 2021
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 16, no. 1 January (2021), p.
- Full Text:
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- Description: Background Anaemia is a significant public health problem in most South-Asian countries, causing increased maternal and child mortality and morbidity. This study aimed to estimate the prevalence of and factors associated with anaemia in women of reproductive age in Bangladesh, Maldives, and Nepal. Methods We used the nationally-representative Demographic and Health Surveys Program data collected from women of reproductive age (15-49 years) in 2011 in Bangladesh (n = 5678), 2016 in Maldives (n = 6837), and 2016 in Nepal (n = 6419). Anaemia was categorized as mild (haemoglobin [Hb] of 10.0-10.9 g/dL for pregnant women and 11.0-11.9 g/dL for non-pregnant women), moderate (Hb of 7.0-9.9 g/dL for pregnant women and 8.0-10.9 g/dL for non-pregnant women), and severe (Hb <7.0 g/dL for pregnant women and <8.0 g/dL for non-pregnant women). Multinomial logistic regression analyses were used to identify factors associated with anaemia. Results The prevalence of anaemia was 41.8% in Bangladesh, 58.5% in Maldives, and 40.6% in Nepal. In Bangladesh, postpartum amenorrhoeic, non-educated, and pregnant women were more likely to have moderate/severe anaemia compared to women who were menopausal, had secondary education, and were not pregnant, respectively. In Maldives, residence in urban areas, underweight, having undergone female sterilization, current pregnancy, and menstruation in the last six weeks were associated with increased odds of moderate/severe anaemia. In Nepal, factors associated with increased odds of moderate/ severe anaemia were having undergone female sterilization and current pregnancy. Conclusion Anaemia remains a significant public health issue among 15-49-year-old women in Bangladesh, Maldives, and Nepal, which requires urgent attention. Effective policies and programmes for the control and prevention of anaemia should take into account the unique factors associated with anaemia identified in each country. In all three countries, strategies for the prevention and control of anaemia should particularly focus on women who are pregnant, underweight, or have undergone sterilization. © 2021 Rahman et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Rockfalls : Predicting high-risk behaviour from beliefs
- Aucote, Helen, Miner, Anthony, Dahlhaus, Peter
- Authors: Aucote, Helen , Miner, Anthony , Dahlhaus, Peter
- Date: 2010
- Type: Journal article
- Relation: Disaster Prevention and Management Vol. 19, no. 1 (2010), p. 20-31
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- Description: Purpose – The purpose of this paper is to gain an understanding of the public's beliefs, attitudes and knowledge regarding rockfalls, and to see whether these variables could predict whether a person is likely to enter high-risk rockfall areas. Design/methodology/approach – A questionnaire was developed to measure beliefs (informed by the health belief model), knowledge, and previous behaviour in relation to rockfalls. Questions were also included to measure attitudes regarding rockfall caution signs. In total, 138 members of the general public completed the questionnaire. Findings – High-risk behaviour was more likely if the person was male and if the person had the belief that sign-posted high-risk areas were not dangerous. Further, believing that the sign-posted areas were not dangerous was more likely among people who held negative attitudes towards cautionary signs; specifically, these participants were more likely to doubt the validity of the warning signs. Research limitations/implications – The research was exploratory in nature. Further research should be conducted with a larger sample size and a more random selection of the general population. Ways of improving measurement of the variables are discussed. Practical implications – Efforts should be made to increase the public's perception of the validity of rockfall cautionary signs. Doing so may decrease injury and death as a result of rockfalls. Suggestions on ways to increase the validity of signage are made. Originality/value – It is presumed that this study is the first to attempt to gain an understanding of the beliefs and attitudes that may lead a person into engaging in high-risk behaviour in relation to rockfalls.
- Authors: Aucote, Helen , Miner, Anthony , Dahlhaus, Peter
- Date: 2010
- Type: Journal article
- Relation: Disaster Prevention and Management Vol. 19, no. 1 (2010), p. 20-31
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- Description: Purpose – The purpose of this paper is to gain an understanding of the public's beliefs, attitudes and knowledge regarding rockfalls, and to see whether these variables could predict whether a person is likely to enter high-risk rockfall areas. Design/methodology/approach – A questionnaire was developed to measure beliefs (informed by the health belief model), knowledge, and previous behaviour in relation to rockfalls. Questions were also included to measure attitudes regarding rockfall caution signs. In total, 138 members of the general public completed the questionnaire. Findings – High-risk behaviour was more likely if the person was male and if the person had the belief that sign-posted high-risk areas were not dangerous. Further, believing that the sign-posted areas were not dangerous was more likely among people who held negative attitudes towards cautionary signs; specifically, these participants were more likely to doubt the validity of the warning signs. Research limitations/implications – The research was exploratory in nature. Further research should be conducted with a larger sample size and a more random selection of the general population. Ways of improving measurement of the variables are discussed. Practical implications – Efforts should be made to increase the public's perception of the validity of rockfall cautionary signs. Doing so may decrease injury and death as a result of rockfalls. Suggestions on ways to increase the validity of signage are made. Originality/value – It is presumed that this study is the first to attempt to gain an understanding of the beliefs and attitudes that may lead a person into engaging in high-risk behaviour in relation to rockfalls.
Modeling the effects of particle shape on damping ratio of dry sand by simple shear testing and artificial intelligence
- Baghbani, Abolfazl, Costa, Susanga, Faradonbeh, Roohoollah, Soltani, Amin, Baghbani, Hasan
- Authors: Baghbani, Abolfazl , Costa, Susanga , Faradonbeh, Roohoollah , Soltani, Amin , Baghbani, Hasan
- Date: 2023
- Type: Text , Journal article
- Relation: Applied Sciences (Switzerland) Vol. 13, no. 7 (2023), p.
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- Description: This study investigates the effects of sand particle shape, in terms of roundness, sphericity and regularity, on the damping ratio of a dry sand material. Twelve different cyclic simple shear testing scenarios were considered and applied using vertical stresses of 50, 150 and 250 kPa and cyclic stress ratios (CSR) of 0.2, 0.3, 0.4 and 0.5 in both constant- and controlled-stress modes. Each testing scenario involved five tests, using the same sand that was reconstructed from its previous cyclic test. On completion of the cyclic tests, corresponding hysteresis loops were established to determine the damping ratio. The results indicated that the minimum and maximum damping ratios for this sand material were 6.9 and 25.5, respectively. It was observed that the shape of the sand particles changed during cyclic loading, becoming progressively more rounded and spherical with an increasing number of loading cycles, thereby resulting in an increase in the damping ratio. The second part of this investigation involved the development of artificial intelligence models, namely an artificial neural network (ANN) and a support vector machine (SVM), to predict the effects of sand particle shape on the damping ratio. The proposed ANN and SVM models were found to be effective in predicting the damping ratio as a function of the particle shape descriptors (i.e., roundness, sphericity and regularity), vertical stress, CSR and number of loading cycles. Finally, a sensitivity analysis was conducted to identify the importance of the input variables; the vertical stress and regularity were, respectively, ranked as first and second in terms of importance, while the CSR was found to be the least important parameter. © 2023 by the authors.
- Authors: Baghbani, Abolfazl , Costa, Susanga , Faradonbeh, Roohoollah , Soltani, Amin , Baghbani, Hasan
- Date: 2023
- Type: Text , Journal article
- Relation: Applied Sciences (Switzerland) Vol. 13, no. 7 (2023), p.
- Full Text:
- Reviewed:
- Description: This study investigates the effects of sand particle shape, in terms of roundness, sphericity and regularity, on the damping ratio of a dry sand material. Twelve different cyclic simple shear testing scenarios were considered and applied using vertical stresses of 50, 150 and 250 kPa and cyclic stress ratios (CSR) of 0.2, 0.3, 0.4 and 0.5 in both constant- and controlled-stress modes. Each testing scenario involved five tests, using the same sand that was reconstructed from its previous cyclic test. On completion of the cyclic tests, corresponding hysteresis loops were established to determine the damping ratio. The results indicated that the minimum and maximum damping ratios for this sand material were 6.9 and 25.5, respectively. It was observed that the shape of the sand particles changed during cyclic loading, becoming progressively more rounded and spherical with an increasing number of loading cycles, thereby resulting in an increase in the damping ratio. The second part of this investigation involved the development of artificial intelligence models, namely an artificial neural network (ANN) and a support vector machine (SVM), to predict the effects of sand particle shape on the damping ratio. The proposed ANN and SVM models were found to be effective in predicting the damping ratio as a function of the particle shape descriptors (i.e., roundness, sphericity and regularity), vertical stress, CSR and number of loading cycles. Finally, a sensitivity analysis was conducted to identify the importance of the input variables; the vertical stress and regularity were, respectively, ranked as first and second in terms of importance, while the CSR was found to be the least important parameter. © 2023 by the authors.
Improving soil stability with alum sludge : an ai-enabled approach for accurate prediction of california bearing ratio
- Baghbani, Abolfazl, Nguyen, Minh, Alnedawi, Ali, Milne, Nick, Baumgartl, Thomas, Abuel-Naga, Hossam
- Authors: Baghbani, Abolfazl , Nguyen, Minh , Alnedawi, Ali , Milne, Nick , Baumgartl, Thomas , Abuel-Naga, Hossam
- Date: 2023
- Type: Text , Journal article
- Relation: Applied Sciences (Switzerland) Vol. 13, no. 8 (2023), p.
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- Description: Alum sludge is a byproduct of water treatment plants, and its use as a soil stabilizer has gained increasing attention due to its economic and environmental benefits. Its application has been shown to improve the strength and stability of soil, making it suitable for various engineering applications. However, to go beyond just measuring the effects of alum sludge as a soil stabilizer, this study investigates the potential of artificial intelligence (AI) methods for predicting the California bearing ratio (CBR) of soils stabilized with alum sludge. Three AI methods, including two black box methods (artificial neural network and support vector machines) and one grey box method (genetic programming), were used to predict CBR, based on a database with nine input parameters. The results demonstrate the effectiveness of AI methods in predicting CBR with good accuracy (R2 values ranging from 0.94 to 0.99 and MAE values ranging from 0.30 to 0.51). Moreover, a novel approach, using genetic programming, produced an equation that accurately estimated CBR, incorporating seven inputs. The analysis of parameter sensitivity and importance, revealed that the number of hammer blows for compaction was the most important parameter, while the parameters for maximum dry density of soil and mixture were the least important. This study highlights the potential of AI methods as a useful tool for predicting the performance of alum sludge as a soil stabilizer. © 2023 by the authors.
- Authors: Baghbani, Abolfazl , Nguyen, Minh , Alnedawi, Ali , Milne, Nick , Baumgartl, Thomas , Abuel-Naga, Hossam
- Date: 2023
- Type: Text , Journal article
- Relation: Applied Sciences (Switzerland) Vol. 13, no. 8 (2023), p.
- Full Text:
- Reviewed:
- Description: Alum sludge is a byproduct of water treatment plants, and its use as a soil stabilizer has gained increasing attention due to its economic and environmental benefits. Its application has been shown to improve the strength and stability of soil, making it suitable for various engineering applications. However, to go beyond just measuring the effects of alum sludge as a soil stabilizer, this study investigates the potential of artificial intelligence (AI) methods for predicting the California bearing ratio (CBR) of soils stabilized with alum sludge. Three AI methods, including two black box methods (artificial neural network and support vector machines) and one grey box method (genetic programming), were used to predict CBR, based on a database with nine input parameters. The results demonstrate the effectiveness of AI methods in predicting CBR with good accuracy (R2 values ranging from 0.94 to 0.99 and MAE values ranging from 0.30 to 0.51). Moreover, a novel approach, using genetic programming, produced an equation that accurately estimated CBR, incorporating seven inputs. The analysis of parameter sensitivity and importance, revealed that the number of hammer blows for compaction was the most important parameter, while the parameters for maximum dry density of soil and mixture were the least important. This study highlights the potential of AI methods as a useful tool for predicting the performance of alum sludge as a soil stabilizer. © 2023 by the authors.
Molecular phylogeny of Burkholderia pseudomallei from a remote region of Papua New Guinea
- Baker, Anthony, Pearson, Talima, Price, Erin, Dale, Julia, Keim, Paul, Hornstra, Heidie, Greenhill, Andrew, Padilla, Gabriel, Warner, Jeffrey
- Authors: Baker, Anthony , Pearson, Talima , Price, Erin , Dale, Julia , Keim, Paul , Hornstra, Heidie , Greenhill, Andrew , Padilla, Gabriel , Warner, Jeffrey
- Date: 2011
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 6, no. 3 (2011), p.
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- Description: Background: The island of New Guinea is located midway between the world's two major melioidosis endemic regions of Australia and Southeast Asia. Previous studies in Papua New Guinea have demonstrated autochthonous melioidosis in Balimo, Western province. In contrast to other regions of endemicity, isolates recovered from both environmental and clinical sources demonstrate narrow genetic diversity over large spatial and temporal scales. Methodology/Principal Findings: We employed molecular typing techniques to determine the phylogenetic relationships of these isolates to each other and to others worldwide to aid in understanding the origins of the Papua New Guinean isolates. Multi-locus sequence typing of the 39 isolates resolved three unique sequence types. Phylogenetic reconstruction and Structure analysis determined that all isolates were genetically closer to those from Australia than those from Southeast Asia. Gene cluster analysis however, identified a Yersinia-like fimbrial gene cluster predominantly found among Burkholderia pseudomallei derived from Southeast Asia. Higher resolution VNTR typing and phylogenetic reconstruction of the Balimo isolates resolved 24 genotypes with long branch lengths. These findings are congruent with long term persistence in the region and a high level of environmental stability. Conclusions/Significance: Given that anthropogenic influence has been hypothesized as a mechanism for the dispersal of B. pseudomallei, these findings correlate with limited movement of the indigenous people in the region. The palaeogeographical and anthropogenic history of Australasia and the results from this study indicate that New Guinea is an important region for the further study of B. pseudomallei origins and dissemination.
- Authors: Baker, Anthony , Pearson, Talima , Price, Erin , Dale, Julia , Keim, Paul , Hornstra, Heidie , Greenhill, Andrew , Padilla, Gabriel , Warner, Jeffrey
- Date: 2011
- Type: Text , Journal article
- Relation: PLoS ONE Vol. 6, no. 3 (2011), p.
- Full Text:
- Reviewed:
- Description: Background: The island of New Guinea is located midway between the world's two major melioidosis endemic regions of Australia and Southeast Asia. Previous studies in Papua New Guinea have demonstrated autochthonous melioidosis in Balimo, Western province. In contrast to other regions of endemicity, isolates recovered from both environmental and clinical sources demonstrate narrow genetic diversity over large spatial and temporal scales. Methodology/Principal Findings: We employed molecular typing techniques to determine the phylogenetic relationships of these isolates to each other and to others worldwide to aid in understanding the origins of the Papua New Guinean isolates. Multi-locus sequence typing of the 39 isolates resolved three unique sequence types. Phylogenetic reconstruction and Structure analysis determined that all isolates were genetically closer to those from Australia than those from Southeast Asia. Gene cluster analysis however, identified a Yersinia-like fimbrial gene cluster predominantly found among Burkholderia pseudomallei derived from Southeast Asia. Higher resolution VNTR typing and phylogenetic reconstruction of the Balimo isolates resolved 24 genotypes with long branch lengths. These findings are congruent with long term persistence in the region and a high level of environmental stability. Conclusions/Significance: Given that anthropogenic influence has been hypothesized as a mechanism for the dispersal of B. pseudomallei, these findings correlate with limited movement of the indigenous people in the region. The palaeogeographical and anthropogenic history of Australasia and the results from this study indicate that New Guinea is an important region for the further study of B. pseudomallei origins and dissemination.
Groundwater seeps facilitate exposure to Burkholderia pseudomallei
- Baker, Anthony, Tahani, Donald, Gardiner, Christopher, Bristow, Keith, Greenhill, Andrew, Warner, Jeffrey
- Authors: Baker, Anthony , Tahani, Donald , Gardiner, Christopher , Bristow, Keith , Greenhill, Andrew , Warner, Jeffrey
- Date: 2011
- Type: Text , Journal article
- Relation: Applied and Environmental Microbiology Vol. 77, no. 20 (2011), p. 7243-7246
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- Description: Burkholderia pseudomallei is a saprophytic bacterium which is the causative agent of melioidosis, a common cause of fatal bacterial pneumonia and sepsis in the tropics. The incidence of melioidosis is clustered spatially and temporally and is heavily linked to rainfall and extreme weather events. Clinical case clustering has recently been reported in Townsville, Australia, and has implicated Castle Hill, a granite monolith in the city center, as a potential reservoir of infection. Topsoil and water from seasonal groundwater seeps were collected around the base of Castle Hill and analyzed by quantitative real-time PCR targeting the type III secretion system genes for the presence of B. pseudomallei. The organism was identified in 65% (95% confidence interval [CI], 49.5 to 80.4) of soil samples (n =40) and 92.5% (95% CI, 83.9 to 100) of seasonal groundwater samples (n =40). Further sampling of water collected from roads and gutters in nearby residential areas after an intense rainfall event found that 88.2% (95% CI, 72.9 to 100) of samples (n =16) contained viable B. pseudomallei at concentrations up to 113 CFU/ml. Comparison of isolates using multilocus sequence typing demonstrated clinical matches and close associations between environmental isolates and isolates derived from clinical samples from patients in Townsville. This study demonstrated that waterborne B. pseudomallei from groundwater seeps around Castle Hill may facilitate exposure to B. pseudomallei and contribute to the clinical clustering at this site. Access to this type of information will advise the development and implementation of public health measures to reduce the incidence of melioidosis. © 2011, American Society for Microbiology.
- Authors: Baker, Anthony , Tahani, Donald , Gardiner, Christopher , Bristow, Keith , Greenhill, Andrew , Warner, Jeffrey
- Date: 2011
- Type: Text , Journal article
- Relation: Applied and Environmental Microbiology Vol. 77, no. 20 (2011), p. 7243-7246
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- Description: Burkholderia pseudomallei is a saprophytic bacterium which is the causative agent of melioidosis, a common cause of fatal bacterial pneumonia and sepsis in the tropics. The incidence of melioidosis is clustered spatially and temporally and is heavily linked to rainfall and extreme weather events. Clinical case clustering has recently been reported in Townsville, Australia, and has implicated Castle Hill, a granite monolith in the city center, as a potential reservoir of infection. Topsoil and water from seasonal groundwater seeps were collected around the base of Castle Hill and analyzed by quantitative real-time PCR targeting the type III secretion system genes for the presence of B. pseudomallei. The organism was identified in 65% (95% confidence interval [CI], 49.5 to 80.4) of soil samples (n =40) and 92.5% (95% CI, 83.9 to 100) of seasonal groundwater samples (n =40). Further sampling of water collected from roads and gutters in nearby residential areas after an intense rainfall event found that 88.2% (95% CI, 72.9 to 100) of samples (n =16) contained viable B. pseudomallei at concentrations up to 113 CFU/ml. Comparison of isolates using multilocus sequence typing demonstrated clinical matches and close associations between environmental isolates and isolates derived from clinical samples from patients in Townsville. This study demonstrated that waterborne B. pseudomallei from groundwater seeps around Castle Hill may facilitate exposure to B. pseudomallei and contribute to the clinical clustering at this site. Access to this type of information will advise the development and implementation of public health measures to reduce the incidence of melioidosis. © 2011, American Society for Microbiology.
Identifying tobacco retailers in the absence of a licensing system : lessons from Australia
- Baker, John, Masood, Mohd, Rahman, Muhammad Aziz, Thornton, Lukar, Begg, Stephen
- Authors: Baker, John , Masood, Mohd , Rahman, Muhammad Aziz , Thornton, Lukar , Begg, Stephen
- Date: 2021
- Type: Text , Journal article
- Relation: Tobacco Control Vol. 31, no. 4 (2021), p. 543-548
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- Description: ObjectivesTo estimate the proportion of retailers that sell tobacco in the absence of appropriate local government oversight, and to describe the characteristics by which they differ from those that can expect to receive such oversight.MethodsA database of listed tobacco retailers was obtained from a regional Victorian local government. Potential unlisted tobacco retailers were added using online searches, and attempts to visit all retailers were undertaken. GPS coordinates and sales type information of retailers that sold tobacco were recorded and attached to neighbourhood-level data on socioeconomic disadvantage and smoking prevalence using ArcMap. Logistic regression analyses, χ2 tests and t-tests were undertaken to explore differences in numbers of listed and unlisted retailers by business and neighbourhood-level characteristics.ResultsOf 125 confirmed tobacco retailers, 43.2% were trading potentially without government oversight. Significant differences were found between listed and unlisted retailers by primary business type (p<0.001), and sales type (p<0.001) but not by the other characteristics.ConclusionsThe database of tobacco retailers was inaccurate in two ways: (1) a number of listed retailers no longer operated or sold tobacco, and (2) 43.2% of businesses confirmed as selling tobacco were missing. As no form of licensing system exists in Victoria, it is difficult to identify the number of retailers operating, or to determine how many receive formal regulatory oversight. A positive licensing system is recommended to regulate the sale of tobacco and to generate a comprehensive database of retailers, similar to that which exists for food registration, gaming and liquor-licensed premises.
- Authors: Baker, John , Masood, Mohd , Rahman, Muhammad Aziz , Thornton, Lukar , Begg, Stephen
- Date: 2021
- Type: Text , Journal article
- Relation: Tobacco Control Vol. 31, no. 4 (2021), p. 543-548
- Full Text:
- Reviewed:
- Description: ObjectivesTo estimate the proportion of retailers that sell tobacco in the absence of appropriate local government oversight, and to describe the characteristics by which they differ from those that can expect to receive such oversight.MethodsA database of listed tobacco retailers was obtained from a regional Victorian local government. Potential unlisted tobacco retailers were added using online searches, and attempts to visit all retailers were undertaken. GPS coordinates and sales type information of retailers that sold tobacco were recorded and attached to neighbourhood-level data on socioeconomic disadvantage and smoking prevalence using ArcMap. Logistic regression analyses, χ2 tests and t-tests were undertaken to explore differences in numbers of listed and unlisted retailers by business and neighbourhood-level characteristics.ResultsOf 125 confirmed tobacco retailers, 43.2% were trading potentially without government oversight. Significant differences were found between listed and unlisted retailers by primary business type (p<0.001), and sales type (p<0.001) but not by the other characteristics.ConclusionsThe database of tobacco retailers was inaccurate in two ways: (1) a number of listed retailers no longer operated or sold tobacco, and (2) 43.2% of businesses confirmed as selling tobacco were missing. As no form of licensing system exists in Victoria, it is difficult to identify the number of retailers operating, or to determine how many receive formal regulatory oversight. A positive licensing system is recommended to regulate the sale of tobacco and to generate a comprehensive database of retailers, similar to that which exists for food registration, gaming and liquor-licensed premises.