Long-term occupational exposures on disability-free survival and mortality in older adults
- Alif, Sheikh, Benke, Geza, Kromhout, Hans, Vermeulen, Roel, Tran, Cammie, Ronaldson, Kathlyn, Walker-Bone, Karen, Woods, Robyn, Beilin, Lawerence, Tonkin, Andrew, Owen, Alice, McNeil, John
- Authors: Alif, Sheikh , Benke, Geza , Kromhout, Hans , Vermeulen, Roel , Tran, Cammie , Ronaldson, Kathlyn , Walker-Bone, Karen , Woods, Robyn , Beilin, Lawerence , Tonkin, Andrew , Owen, Alice , McNeil, John
- Date: 2023
- Type: Text , Journal article
- Relation: Occupational Medicine Vol. 73, no. 8 (2023), p. 492-499
- Full Text:
- Reviewed:
- Description: Background The impact of long-term occupational exposures on health in older adults is increasingly relevant as populations age. To date, no studies have reported their impact on survival free of disability in older adults. Aims We aimed to investigate the association between long-term occupational exposure and disability-free survival (DFS), all-cause mortality and cause-specific mortality in initially healthy older adults. Methods We analysed data from 12 215 healthy participants in the ASPirin in Reducing Events in the Elderly (ASPREE) study whose mean age was 75 years. Their work history was collated with the ‘ALOHA-plus JEM’ (Job Exposure Matrix) to assign occupational exposures. The primary endpoint, DFS, was a composite measure of death, dementia or persistent physical disability. The secondary endpoint, mortality, was classified according to the underlying cause. Cox proportional hazard models were used to calculate hazard ratios and 95% confidence intervals, adjusted for confounders. Results A total of 1835 individuals reached the DFS endpoint during the median 4.7 years follow-up period. Both ever-high and cumulative exposure to all dusts and all pesticides during a person’s working years were associated with reduced DFS. Compared to no exposure, men with high exposure to dusts and pesticides had a reduced DFS. Neither of these exposures were significantly associated with all-cause mortality. Men with high occupational exposure to solvents and women exposed to dusts experienced higher all-cause and cancer-related mortality. Conclusions Long-term occupational exposure to all dusts and pesticides was associated with a reduced DFS and increased mortality in community-dwelling healthy older adults. © The Author(s) 2023. Published by Oxford University Press on behalf of the Society of Occupational Medicine.
- Authors: Alif, Sheikh , Benke, Geza , Kromhout, Hans , Vermeulen, Roel , Tran, Cammie , Ronaldson, Kathlyn , Walker-Bone, Karen , Woods, Robyn , Beilin, Lawerence , Tonkin, Andrew , Owen, Alice , McNeil, John
- Date: 2023
- Type: Text , Journal article
- Relation: Occupational Medicine Vol. 73, no. 8 (2023), p. 492-499
- Full Text:
- Reviewed:
- Description: Background The impact of long-term occupational exposures on health in older adults is increasingly relevant as populations age. To date, no studies have reported their impact on survival free of disability in older adults. Aims We aimed to investigate the association between long-term occupational exposure and disability-free survival (DFS), all-cause mortality and cause-specific mortality in initially healthy older adults. Methods We analysed data from 12 215 healthy participants in the ASPirin in Reducing Events in the Elderly (ASPREE) study whose mean age was 75 years. Their work history was collated with the ‘ALOHA-plus JEM’ (Job Exposure Matrix) to assign occupational exposures. The primary endpoint, DFS, was a composite measure of death, dementia or persistent physical disability. The secondary endpoint, mortality, was classified according to the underlying cause. Cox proportional hazard models were used to calculate hazard ratios and 95% confidence intervals, adjusted for confounders. Results A total of 1835 individuals reached the DFS endpoint during the median 4.7 years follow-up period. Both ever-high and cumulative exposure to all dusts and all pesticides during a person’s working years were associated with reduced DFS. Compared to no exposure, men with high exposure to dusts and pesticides had a reduced DFS. Neither of these exposures were significantly associated with all-cause mortality. Men with high occupational exposure to solvents and women exposed to dusts experienced higher all-cause and cancer-related mortality. Conclusions Long-term occupational exposure to all dusts and pesticides was associated with a reduced DFS and increased mortality in community-dwelling healthy older adults. © The Author(s) 2023. Published by Oxford University Press on behalf of the Society of Occupational Medicine.
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.
- 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.
- 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.
Computing elastic moduli of igneous rocks using modal composition and effective medium theory
- Aligholi, Saeed, Khandelwal, Manoj
- Authors: Aligholi, Saeed , Khandelwal, Manoj
- Date: 2022
- Type: Text , Journal article
- Relation: Geosciences (Switzerland) Vol. 12, no. 11 (2022), p.
- Full Text:
- Reviewed:
- Description: Elastic constants of rock materials are the basic parameters required for modeling the response of rock materials under mechanical loads. Experimental tests for determining these properties are expensive, time-consuming and suffer from a high uncertainty due to both experimental limitations and the heterogeneous nature of rock materials. To avoid such experimental difficulties, in this paper a method is suggested for determining elastic constants of rock materials by determining their porosity and modal composition and employing effective medium theory. The Voigt–Reuss–Hill average is used to determine effective elastic constants of the studied igneous rocks according to the elastic moduli of their mineral constituents. Then, the effect of porosity has been taken into account by considering rock as a two-phase material, and the Kuster–Toksoz formulation is used for providing a close estimation of different moduli. The solutions are provided for different isotropic igneous rocks. This sustainable method avoids destructive tests and the usage of energy for performing time-consuming and expensive tests and requires simple equipment. © 2022 by the authors.
- Authors: Aligholi, Saeed , Khandelwal, Manoj
- Date: 2022
- Type: Text , Journal article
- Relation: Geosciences (Switzerland) Vol. 12, no. 11 (2022), p.
- Full Text:
- Reviewed:
- Description: Elastic constants of rock materials are the basic parameters required for modeling the response of rock materials under mechanical loads. Experimental tests for determining these properties are expensive, time-consuming and suffer from a high uncertainty due to both experimental limitations and the heterogeneous nature of rock materials. To avoid such experimental difficulties, in this paper a method is suggested for determining elastic constants of rock materials by determining their porosity and modal composition and employing effective medium theory. The Voigt–Reuss–Hill average is used to determine effective elastic constants of the studied igneous rocks according to the elastic moduli of their mineral constituents. Then, the effect of porosity has been taken into account by considering rock as a two-phase material, and the Kuster–Toksoz formulation is used for providing a close estimation of different moduli. The solutions are provided for different isotropic igneous rocks. This sustainable method avoids destructive tests and the usage of energy for performing time-consuming and expensive tests and requires simple equipment. © 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.
- 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
- 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
Quantifying the cohesive strength of rock materials by roughness analysis using a domain based multifractal framework
- Aligholi, Saeed, Torabi, Ali, Khandelwal, Manoj
- Authors: Aligholi, Saeed , Torabi, Ali , Khandelwal, Manoj
- Date: 2023
- Type: Text , Journal article
- Relation: International Journal of Rock Mechanics and Mining Sciences Vol. 170, no. (2023), p.
- Full Text:
- Reviewed:
- Description: Cohesive strength or intrinsic tensile strength as well as cohesive length are two important unknowns for cohesive modelling of fracture and failure analysis of quasi-brittle materials including rocks. There is no direct method for measuring these parameters and their quantification is always challenging and controversial. In this study, a novel multifractal framework is employed to quantify the cohesive length of four different rock types including sandstone, marble, fine-grained granite and coarse-grained granite by analysing the roughness of their fracture surfaces in a wide range of length scales. On the one hand, microstructural heterogeneities of rock material at small enough length scales will cause multifractality of the roughness of its fractured surface. On the other hand, this intrinsic heterogeneity together with extrinsic features including loading and environmental conditions as well as geometrical features including shape and size of a quasi-brittle specimen or structure are forming a fracture process zone (FPZ) in front of any stress concentrators before crack propagation. Therefore, it is proposed that locating the transition from multifractality to mono-fractality of a rough rock fractured surface using the employed statistical mechanics method leads to quantifying the effective length of FPZ of a sharp crack or the cohesive length. This length is quantified for the studied rocks ranging from 0.4 to 1.1 mm. Moreover, by employing the theory of critical distances, the cohesive strength
- Authors: Aligholi, Saeed , Torabi, Ali , Khandelwal, Manoj
- Date: 2023
- Type: Text , Journal article
- Relation: International Journal of Rock Mechanics and Mining Sciences Vol. 170, no. (2023), p.
- Full Text:
- Reviewed:
- Description: Cohesive strength or intrinsic tensile strength as well as cohesive length are two important unknowns for cohesive modelling of fracture and failure analysis of quasi-brittle materials including rocks. There is no direct method for measuring these parameters and their quantification is always challenging and controversial. In this study, a novel multifractal framework is employed to quantify the cohesive length of four different rock types including sandstone, marble, fine-grained granite and coarse-grained granite by analysing the roughness of their fracture surfaces in a wide range of length scales. On the one hand, microstructural heterogeneities of rock material at small enough length scales will cause multifractality of the roughness of its fractured surface. On the other hand, this intrinsic heterogeneity together with extrinsic features including loading and environmental conditions as well as geometrical features including shape and size of a quasi-brittle specimen or structure are forming a fracture process zone (FPZ) in front of any stress concentrators before crack propagation. Therefore, it is proposed that locating the transition from multifractality to mono-fractality of a rough rock fractured surface using the employed statistical mechanics method leads to quantifying the effective length of FPZ of a sharp crack or the cohesive length. This length is quantified for the studied rocks ranging from 0.4 to 1.1 mm. Moreover, by employing the theory of critical distances, the cohesive strength
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.
Bone char as a green sorbent for removing health threatening fluoride from drinking water
- Alkurdi, Susan, Al-Juboori, Raed, Bundschuh, Jochen, Hamawand, Ihsan
- Authors: Alkurdi, Susan , Al-Juboori, Raed , Bundschuh, Jochen , Hamawand, Ihsan
- Date: 2019
- Type: Text , Journal article , Review
- Relation: Environment International Vol. 127, no. (2019), p. 704-719
- Full Text:
- Reviewed:
- Description: Millions of people around the world suffer from or prone to health problems caused by high concentration of fluoride in drinking water sources. One of the environmentally friendly and cost-effective ways for removing fluoride is the use of bone char. In this review, the structural properties and binding affinity of fluoride ions from different water sources was critically discussed. The effect of experimental conditions on enhancing the adsorption capacity of fluoride ions using bone char samples was addressed. It appears that surface properties, and conditions of the bone char production such as temperature and residence time play an important role in designing the optimal fluoride removal process. The optimum temperature for fluoride removal seems to be in the range of 500–700 °C and a residence time of 2 h. Applying various equilibrium adsorption isotherms for understanding fluoride adsorption mechanism was presented. The effect of bone char modification with different elements were discussed and recommendations for a further increase in the removal efficiency was proposed. Cost of bone char production and large-scale treatment systems were also discussed based on information available from scientific and commercial sources. Challenges with existing domestic defluoridation designs were highlighted and suggestions for new conceptual designs were provided.
- Authors: Alkurdi, Susan , Al-Juboori, Raed , Bundschuh, Jochen , Hamawand, Ihsan
- Date: 2019
- Type: Text , Journal article , Review
- Relation: Environment International Vol. 127, no. (2019), p. 704-719
- Full Text:
- Reviewed:
- Description: Millions of people around the world suffer from or prone to health problems caused by high concentration of fluoride in drinking water sources. One of the environmentally friendly and cost-effective ways for removing fluoride is the use of bone char. In this review, the structural properties and binding affinity of fluoride ions from different water sources was critically discussed. The effect of experimental conditions on enhancing the adsorption capacity of fluoride ions using bone char samples was addressed. It appears that surface properties, and conditions of the bone char production such as temperature and residence time play an important role in designing the optimal fluoride removal process. The optimum temperature for fluoride removal seems to be in the range of 500–700 °C and a residence time of 2 h. Applying various equilibrium adsorption isotherms for understanding fluoride adsorption mechanism was presented. The effect of bone char modification with different elements were discussed and recommendations for a further increase in the removal efficiency was proposed. Cost of bone char production and large-scale treatment systems were also discussed based on information available from scientific and commercial sources. Challenges with existing domestic defluoridation designs were highlighted and suggestions for new conceptual designs were provided.
Biochar versus bone char for a sustainable inorganic arsenic mitigation in water : What needs to be done in future research?
- Alkurdi, Susan, Herath, Indika, Bundschuh, Jochen, Al-Juboori, Raed, Vithanage, Meththika, Mohan, Dinesh
- Authors: Alkurdi, Susan , Herath, Indika , Bundschuh, Jochen , Al-Juboori, Raed , Vithanage, Meththika , Mohan, Dinesh
- Date: 2019
- Type: Text , Journal article , Review
- Relation: Environment International Vol. 127, no. (2019), p. 52-69
- Full Text:
- Reviewed:
- Description: Arsenic (As) is an emerging contaminant on a global scale posing threat to environmental and human health. The relatively brief history of the applications of biochar and bone char has mapped the endeavors to remove As from water to a considerable extent. This critical review attempts to provide a comprehensive overview for the first time on the potential of bio- and bone-char in the immobilization of inorganic As in water. It seeks to offer a rational assessment of what is existing and what needs to be done in future research as an implication for As toxicity of human health risks through acute and chronic exposure to As contaminated water. Bio- and bone-char are recognized as promising alternatives to activated carbon due to their lower production and activation cost. The surface modification via chemical methods has been adopted to improve the adsorption capacity for anionic As species. Surface complexation, ion exchange, precipitation and electrostatic interactions are the main mechanisms involved in the adsorption of As onto the char surface. However, arsenic-bio-bone char interactions along with their chemical bonding for the removal of As in aqueous solution is still a subject of debate. Hence, the proposed mechanisms need to be scrutinized further using advanced analytical techniques such as synchrotron-based X-ray. Moving this technology from laboratory phase to field scale applications is an urgent necessity in order to establish a sustainable As mitigation in drinking water on a global scale.
- Authors: Alkurdi, Susan , Herath, Indika , Bundschuh, Jochen , Al-Juboori, Raed , Vithanage, Meththika , Mohan, Dinesh
- Date: 2019
- Type: Text , Journal article , Review
- Relation: Environment International Vol. 127, no. (2019), p. 52-69
- Full Text:
- Reviewed:
- Description: Arsenic (As) is an emerging contaminant on a global scale posing threat to environmental and human health. The relatively brief history of the applications of biochar and bone char has mapped the endeavors to remove As from water to a considerable extent. This critical review attempts to provide a comprehensive overview for the first time on the potential of bio- and bone-char in the immobilization of inorganic As in water. It seeks to offer a rational assessment of what is existing and what needs to be done in future research as an implication for As toxicity of human health risks through acute and chronic exposure to As contaminated water. Bio- and bone-char are recognized as promising alternatives to activated carbon due to their lower production and activation cost. The surface modification via chemical methods has been adopted to improve the adsorption capacity for anionic As species. Surface complexation, ion exchange, precipitation and electrostatic interactions are the main mechanisms involved in the adsorption of As onto the char surface. However, arsenic-bio-bone char interactions along with their chemical bonding for the removal of As in aqueous solution is still a subject of debate. Hence, the proposed mechanisms need to be scrutinized further using advanced analytical techniques such as synchrotron-based X-ray. Moving this technology from laboratory phase to field scale applications is an urgent necessity in order to establish a sustainable As mitigation in drinking water on a global scale.
Cardiovascular data analytics for real time patient monitoring
- Authors: Allami, Ragheed
- Date: 2017
- Type: Text , Thesis , PhD
- Full Text:
- Description: Improvements in wearable sensor devices make it possible to constantly monitor physiological parameters such as electrocardiograph (ECG) signals for long periods. Remote patient monitoring with wearable sensors has an important role to play in health care, particularly given the prevalence of chronic conditions such as cardiovascular disease (CVD)—one of the prominent causes of morbidity and mortality worldwide. Approximately 4.2 million Australians suffer from long-term CVD with approximately one death every 12 minutes. The assessment of ECG features, especially heart rate variability (HRV), represents a non-invasive technique which provides an indication of the autonomic nervous system (ANS) function. Conditions such as sudden cardiac death, hypertension, heart failure, myocardial infarction, ischaemia, and coronary heart disease can be detected from HRV analysis. In addition, the analysis of ECG features can also be used to diagnose many types of life-threatening arrhythmias, including ventricular fibrillation and ventricular tachycardia. Non-cardiac conditions, such as diabetes, obesity, metabolic syndrome, insulin resistance, irritable bowel syndrome, dyspepsia, anorexia nervosa, anxiety, and major depressive disorder have also been shown to be associated with HRV. The analysis of ECG features from real time ECG signals generated from wearable sensors provides distinctive challenges. The sensors that receive and process the signals have limited power, storage and processing capacity. Consequently, algorithms that process ECG signals need to be lightweight, use minimal storage resources and accurately detect abnormalities so that alarms can be raised. The existing literature details only a few algorithms which operate within the constraints of wearable sensor networks. This research presents four novel techniques that enable ECG signals to be processed within the limitations of resource constraints on devices to detect some key abnormalities in heart function. - The first technique is a novel real-time ECG data reduction algorithm, which detects and transmits only those key points that are critical for the generation of ECG features for diagnoses. - The second technique accurately predicts the five-minute HRV measure using only three minutes of data with an algorithm that executes in real-time using minimal computational resources. - The third technique introduces a real-time ECG feature recognition system that can be applied to diagnose life threatening conditions such as premature ventricular contractions (PVCs). - The fourth technique advances a classification algorithm to enhance the performance of automated ECG classification to determine arrhythmic heart beats based on noisy ECG signals. The four novel techniques are evaluated in comparison with benchmark algorithms for each task on the standard MIT-BIH Arrhythmia Database and with data generated from patients in a major hospital using Shimmer3 wearable ECG sensors. The four techniques are integrated to demonstrate that remote patient monitoring of ECG using HRV and ECG features is feasible in real time using minimal computational resources. The evaluation show that the ECG reduction algorithm is significantly better than existing algorithms that can be applied within sensor nodes, such as time-domain methods, transformation methods and compressed sensing methods. Furthermore, the proposed ECG reduction is found to be computationally less complex for resource constrained sensors and achieves higher compression ratios than existing algorithms. The prediction of a common HRV measure, the five-minute standard deviation of inter-beat variations (SDNN) and the accurate detection of PVC beats was achieved using a Count Data Model, combined with a Poisson-generated function from three-minute ECG recordings. This was achieved with minimal computational resources and was well suited to remote patient monitoring with wearable sensors. The PVC beats detection was implemented using the same count data model together with knowledge-based rules derived from clinical knowledge. A real-time cardiac patient monitoring system was implemented using an ECG sensor and smartphone to detect PVC beats within a few seconds using artificial neural networks (ANN), and it was proven to provide highly accurate results. The automated detection and classification were implemented using a new wrapper-based hybrid approach that utilized t-distributed stochastic neighbour embedding (t-SNE) in combination with self-organizing maps (SOM) to improve classification performance. The t-SNE-SOM hybrid resulted in improved sensitivity, specificity and accuracy compared to most common hybrid methods in the presence of noise. It also provided a better, more accurate identification for the presence of many types of arrhythmias from the ECG recordings, leading to a more timely diagnosis and treatment outcome.
- Description: Doctor of Philosophy
- Authors: Allami, Ragheed
- Date: 2017
- Type: Text , Thesis , PhD
- Full Text:
- Description: Improvements in wearable sensor devices make it possible to constantly monitor physiological parameters such as electrocardiograph (ECG) signals for long periods. Remote patient monitoring with wearable sensors has an important role to play in health care, particularly given the prevalence of chronic conditions such as cardiovascular disease (CVD)—one of the prominent causes of morbidity and mortality worldwide. Approximately 4.2 million Australians suffer from long-term CVD with approximately one death every 12 minutes. The assessment of ECG features, especially heart rate variability (HRV), represents a non-invasive technique which provides an indication of the autonomic nervous system (ANS) function. Conditions such as sudden cardiac death, hypertension, heart failure, myocardial infarction, ischaemia, and coronary heart disease can be detected from HRV analysis. In addition, the analysis of ECG features can also be used to diagnose many types of life-threatening arrhythmias, including ventricular fibrillation and ventricular tachycardia. Non-cardiac conditions, such as diabetes, obesity, metabolic syndrome, insulin resistance, irritable bowel syndrome, dyspepsia, anorexia nervosa, anxiety, and major depressive disorder have also been shown to be associated with HRV. The analysis of ECG features from real time ECG signals generated from wearable sensors provides distinctive challenges. The sensors that receive and process the signals have limited power, storage and processing capacity. Consequently, algorithms that process ECG signals need to be lightweight, use minimal storage resources and accurately detect abnormalities so that alarms can be raised. The existing literature details only a few algorithms which operate within the constraints of wearable sensor networks. This research presents four novel techniques that enable ECG signals to be processed within the limitations of resource constraints on devices to detect some key abnormalities in heart function. - The first technique is a novel real-time ECG data reduction algorithm, which detects and transmits only those key points that are critical for the generation of ECG features for diagnoses. - The second technique accurately predicts the five-minute HRV measure using only three minutes of data with an algorithm that executes in real-time using minimal computational resources. - The third technique introduces a real-time ECG feature recognition system that can be applied to diagnose life threatening conditions such as premature ventricular contractions (PVCs). - The fourth technique advances a classification algorithm to enhance the performance of automated ECG classification to determine arrhythmic heart beats based on noisy ECG signals. The four novel techniques are evaluated in comparison with benchmark algorithms for each task on the standard MIT-BIH Arrhythmia Database and with data generated from patients in a major hospital using Shimmer3 wearable ECG sensors. The four techniques are integrated to demonstrate that remote patient monitoring of ECG using HRV and ECG features is feasible in real time using minimal computational resources. The evaluation show that the ECG reduction algorithm is significantly better than existing algorithms that can be applied within sensor nodes, such as time-domain methods, transformation methods and compressed sensing methods. Furthermore, the proposed ECG reduction is found to be computationally less complex for resource constrained sensors and achieves higher compression ratios than existing algorithms. The prediction of a common HRV measure, the five-minute standard deviation of inter-beat variations (SDNN) and the accurate detection of PVC beats was achieved using a Count Data Model, combined with a Poisson-generated function from three-minute ECG recordings. This was achieved with minimal computational resources and was well suited to remote patient monitoring with wearable sensors. The PVC beats detection was implemented using the same count data model together with knowledge-based rules derived from clinical knowledge. A real-time cardiac patient monitoring system was implemented using an ECG sensor and smartphone to detect PVC beats within a few seconds using artificial neural networks (ANN), and it was proven to provide highly accurate results. The automated detection and classification were implemented using a new wrapper-based hybrid approach that utilized t-distributed stochastic neighbour embedding (t-SNE) in combination with self-organizing maps (SOM) to improve classification performance. The t-SNE-SOM hybrid resulted in improved sensitivity, specificity and accuracy compared to most common hybrid methods in the presence of noise. It also provided a better, more accurate identification for the presence of many types of arrhythmias from the ECG recordings, leading to a more timely diagnosis and treatment outcome.
- Description: Doctor of Philosophy
ECG reduction for wearable sensor
- Allami, Ragheed, Stranieri, Andrew, Balasubramanian, Venki, Jelinek, Herbert
- Authors: Allami, Ragheed , Stranieri, Andrew , Balasubramanian, Venki , Jelinek, Herbert
- Date: 2016
- Type: Text , Conference proceedings
- Relation: 2016 12th International Conference on Signal-Image Technology & Internet-Based Systems (SITIS); Naples, Italy; 28th November-1st December 2016 p. 520-525
- Full Text:
- Reviewed:
- Description: The transmission, storage and analysis of electrocardiogram (ECG) data in real-time is essential for remote patient monitoring with wearable ECG devices and mobile ECG contexts. However, this remains a challenge to achieve within the processing power and the storage capacity of mobile devices. ECG reduction algorithms have an important role to play in reducing the processing requirements for mobile devices, however many existing ECG reduction and compression algorithms are computationally expensive to execute in mobile devices and have not been designed for real-time computation and incremental data arrival. In this paper, we describe a computationally naive, yet effective, algorithm that achieves high ECG reduction rates while maintaining key diagnostic features including PR, QRS, ST, QT and RR intervals. While reduction does not enable ECG waves to be reproduced, the ability to transmit key indicators (diagnostic features) using minimal computational resources, is particularly useful in mobile health contexts involving power constrained sensors and devices. Results of the proposed reduction algorithm indicate that the proposed algorithm outperforms other ECG reduction algorithms at a reduction/compression ratio (CR) of 5:1. If power or processing capacity is low, the algorithm can readily switch to a compression ratio of up to 10: 1 while still maintaining an error rate below 10%.
- Authors: Allami, Ragheed , Stranieri, Andrew , Balasubramanian, Venki , Jelinek, Herbert
- Date: 2016
- Type: Text , Conference proceedings
- Relation: 2016 12th International Conference on Signal-Image Technology & Internet-Based Systems (SITIS); Naples, Italy; 28th November-1st December 2016 p. 520-525
- Full Text:
- Reviewed:
- Description: The transmission, storage and analysis of electrocardiogram (ECG) data in real-time is essential for remote patient monitoring with wearable ECG devices and mobile ECG contexts. However, this remains a challenge to achieve within the processing power and the storage capacity of mobile devices. ECG reduction algorithms have an important role to play in reducing the processing requirements for mobile devices, however many existing ECG reduction and compression algorithms are computationally expensive to execute in mobile devices and have not been designed for real-time computation and incremental data arrival. In this paper, we describe a computationally naive, yet effective, algorithm that achieves high ECG reduction rates while maintaining key diagnostic features including PR, QRS, ST, QT and RR intervals. While reduction does not enable ECG waves to be reproduced, the ability to transmit key indicators (diagnostic features) using minimal computational resources, is particularly useful in mobile health contexts involving power constrained sensors and devices. Results of the proposed reduction algorithm indicate that the proposed algorithm outperforms other ECG reduction algorithms at a reduction/compression ratio (CR) of 5:1. If power or processing capacity is low, the algorithm can readily switch to a compression ratio of up to 10: 1 while still maintaining an error rate below 10%.
A count data model for heart rate variability forecasting and premature ventricular contraction detection
- Allami, Ragheed, Stranieri, Andrew, Balasubramanian, Venki, Jelinek, Herbert
- Authors: Allami, Ragheed , Stranieri, Andrew , Balasubramanian, Venki , Jelinek, Herbert
- Date: 2017
- Type: Text , Journal article
- Relation: Signal Image and Video Processing Vol. 11, no. 8 (2017), p. 1427-1435
- Full Text:
- Reviewed:
- Description: Heart rate variability (HRV) measures including the standard deviation of inter-beat variations (SDNN) require at least 5 min of ECG recordings to accurately measure HRV. In this paper, we predict, using counts data derived from a 3-min ECG recording, the 5-min SDNN and also detect premature ventricular contraction (PVC) beats with a high degree of accuracy. The approach uses counts data combined with a Poisson-generated function that requires minimal computational resources and is well suited to remote patient monitoring with wearable sensors that have limited power, storage and processing capacity. The ease of use and accuracy of the algorithm provide opportunity for accurate assessment of HRV and reduce the time taken to review patients in real time. The PVC beat detection is implemented using the same count data model together with knowledge-based rules derived from clinical knowledge.
- Authors: Allami, Ragheed , Stranieri, Andrew , Balasubramanian, Venki , Jelinek, Herbert
- Date: 2017
- Type: Text , Journal article
- Relation: Signal Image and Video Processing Vol. 11, no. 8 (2017), p. 1427-1435
- Full Text:
- Reviewed:
- Description: Heart rate variability (HRV) measures including the standard deviation of inter-beat variations (SDNN) require at least 5 min of ECG recordings to accurately measure HRV. In this paper, we predict, using counts data derived from a 3-min ECG recording, the 5-min SDNN and also detect premature ventricular contraction (PVC) beats with a high degree of accuracy. The approach uses counts data combined with a Poisson-generated function that requires minimal computational resources and is well suited to remote patient monitoring with wearable sensors that have limited power, storage and processing capacity. The ease of use and accuracy of the algorithm provide opportunity for accurate assessment of HRV and reduce the time taken to review patients in real time. The PVC beat detection is implemented using the same count data model together with knowledge-based rules derived from clinical knowledge.
Australian nursing students’ perceptions of being a nurse : a mixed methods study
- Authors: Allen, Louise
- Date: 2023
- Type: Text , Thesis , PhD
- Full Text:
- Description: Background Nursing students often enter nursing programs with idealistic, altruistic perceptions of what it means to be a nurse. Over time, however, many discover that these perceptions are naïve and unrealistic. Nursing is a demanding profession that requires knowledge, skill and emotional resilience in often demanding and challenging situations that can influence emotional intelligence. Therefore, an early and realistic understanding of professional requirements may reduce transition shock and attrition rates. Aim The aim of this thesis is to explore Bachelor of Nursing (BN) students’ perceptions of being a nurse in Australia. Methods This study used an explanatory sequential mixed methods design. The 34-item Perceptions of a Registered Nurse (PRN) survey tool was developed using a Nominal Group Technique and validated with a sample of 797 participants across three universities and states. Descriptive and inferential statistical analysis was incorporated as applicable. In addition, online semi-structured interviews with 23 nursing students (n = 23) explored their perceptions of a nurse in detail, with a thematic analysis of outcomes. Results Demographic variables influenced perceptions. There were significant differences in item-by-item perceptions related to ‘primary language spoken at home’ (13/34 items; p < .04), ‘university of study’ (10/34 items; p
- Description: Doctor of Philosophy
- Authors: Allen, Louise
- Date: 2023
- Type: Text , Thesis , PhD
- Full Text:
- Description: Background Nursing students often enter nursing programs with idealistic, altruistic perceptions of what it means to be a nurse. Over time, however, many discover that these perceptions are naïve and unrealistic. Nursing is a demanding profession that requires knowledge, skill and emotional resilience in often demanding and challenging situations that can influence emotional intelligence. Therefore, an early and realistic understanding of professional requirements may reduce transition shock and attrition rates. Aim The aim of this thesis is to explore Bachelor of Nursing (BN) students’ perceptions of being a nurse in Australia. Methods This study used an explanatory sequential mixed methods design. The 34-item Perceptions of a Registered Nurse (PRN) survey tool was developed using a Nominal Group Technique and validated with a sample of 797 participants across three universities and states. Descriptive and inferential statistical analysis was incorporated as applicable. In addition, online semi-structured interviews with 23 nursing students (n = 23) explored their perceptions of a nurse in detail, with a thematic analysis of outcomes. Results Demographic variables influenced perceptions. There were significant differences in item-by-item perceptions related to ‘primary language spoken at home’ (13/34 items; p < .04), ‘university of study’ (10/34 items; p
- Description: Doctor of Philosophy
Perceptions of being a registered nurse (PRN) : development and validation of a survey tool
- Allen, Louise, Cooper, Simon, Missen, Karen
- Authors: Allen, Louise , Cooper, Simon , Missen, Karen
- Date: 2023
- Type: Text , Journal article
- Relation: BMC Nursing Vol. 22, no. 1 (2023), p.
- Full Text:
- Reviewed:
- Description: Background: Nursing students enter nursing programs with idealistic perceptions of what it is to be a nurse. Upon graduation, many find these perceptions mismatched with the actual nurse’s role. This can lead to discontentment in their chosen career. These issues highlight the importance of nursing students developing an understanding of the nurse’s role during their undergraduate nursing education. One way to accomplish this is to assess perceptions and address them accordingly during the nursing program. Survey tools assessing perceptions of nursing exist but lack contemporary and multicultural foci. Aim: To develop a feasible, valid, and reliable survey tool to identify nursing students’ perceptions of being a nurse. Design/Methods: In Phase 1, a literature review and Nominal Group Technique meetings were used to generate primary survey items. Phase 2 included a pre-pilot and online pilot testing of the Perceptions of being a Registered Nurse (PRN) survey tool with 797 nursing students across all year levels at three Australian Universities. Results: The 34-item PRN survey tool uses a five-point Likert scale to measure nursing students’ perceptions of nursing, including factors influencing a nurse’s well-being, attributes and qualities of nurses, the role of the nurse, and nursing professionalism. The Item-Content validity index was high (> 0.78), and the inter-item correlation validity was identified by Pearson’s product-moment coefficient of r =.712. Internal reliability was confirmed with a Cronbach’s alpha = 0.83. Based upon the participation completion rate, the survey tool was deemed applicable and feasible. The majority of respondents believed that nurses have altruistic attributes; however, perceptions of nursing varied significantly when rating factors influencing the physical, emotional, and social well-being of a nurse. In later stages of training, respondents were more likely to agree that nursing is physically and emotionally demanding and that nurses experience social isolation due to shift work, finding it difficult to achieve a work-life balance. Conclusions: The PRN survey tool was found to be valid, reliable, and feasible. Future use and outcomes from PRN assessments may lead to changes to nursing curricula that enhance nursing students’ perceptions of nursing. © 2023, The Author(s).
- Authors: Allen, Louise , Cooper, Simon , Missen, Karen
- Date: 2023
- Type: Text , Journal article
- Relation: BMC Nursing Vol. 22, no. 1 (2023), p.
- Full Text:
- Reviewed:
- Description: Background: Nursing students enter nursing programs with idealistic perceptions of what it is to be a nurse. Upon graduation, many find these perceptions mismatched with the actual nurse’s role. This can lead to discontentment in their chosen career. These issues highlight the importance of nursing students developing an understanding of the nurse’s role during their undergraduate nursing education. One way to accomplish this is to assess perceptions and address them accordingly during the nursing program. Survey tools assessing perceptions of nursing exist but lack contemporary and multicultural foci. Aim: To develop a feasible, valid, and reliable survey tool to identify nursing students’ perceptions of being a nurse. Design/Methods: In Phase 1, a literature review and Nominal Group Technique meetings were used to generate primary survey items. Phase 2 included a pre-pilot and online pilot testing of the Perceptions of being a Registered Nurse (PRN) survey tool with 797 nursing students across all year levels at three Australian Universities. Results: The 34-item PRN survey tool uses a five-point Likert scale to measure nursing students’ perceptions of nursing, including factors influencing a nurse’s well-being, attributes and qualities of nurses, the role of the nurse, and nursing professionalism. The Item-Content validity index was high (> 0.78), and the inter-item correlation validity was identified by Pearson’s product-moment coefficient of r =.712. Internal reliability was confirmed with a Cronbach’s alpha = 0.83. Based upon the participation completion rate, the survey tool was deemed applicable and feasible. The majority of respondents believed that nurses have altruistic attributes; however, perceptions of nursing varied significantly when rating factors influencing the physical, emotional, and social well-being of a nurse. In later stages of training, respondents were more likely to agree that nursing is physically and emotionally demanding and that nurses experience social isolation due to shift work, finding it difficult to achieve a work-life balance. Conclusions: The PRN survey tool was found to be valid, reliable, and feasible. Future use and outcomes from PRN assessments may lead to changes to nursing curricula that enhance nursing students’ perceptions of nursing. © 2023, The Author(s).
Susceptibility of rehabilitated mine batter surface to mass movement
- Authors: Allen, Tristan
- Date: 2018
- Type: Text , Thesis , Masters
- Full Text:
- Description: The goal of the research is to quantify coal properties that may affect the processes and controls governing rehabilitated brown coal mine surface mass movements. The research investigates weathering of coal and assesses the difference in strength characteristics between fresh and weathered coal. In addition to quantifying the mechanical properties of coal surfaces in a rehabilitated slope, permeability changes due to weathering of coal are also investigated. Changes in coal strength influence sliding resistance. Changes in coal permeability impact pore pressures above the coal surface, which may also affect sliding resistance on the coal – cover interface. To assess these issues, direct and residual shear tests were used to investigate the changes in shear strength due to weathering at low normal stresses applicable to shallow cover materials. Testing was undertaken with abrasive surfaces to simulate sliding on the contact coal surface beneath cover materials assuming that the cover material is stronger than the coal. The roughness of the abrasive surface proved to be unimportant for large strain shear strength. The shear strength for coal with different weathering and normal effective stresses was examined. Coal cohesion was found to be low, but some rebinding of coal would occur with time. A coal residual friction angle of 39.1 and 37.0 degrees was found for the unsaturated and saturated tested coal respectively. Permeability tests using oxygenated water were undertaken to investigate changes to brown coal permeability as a result of weathering. Even with low levels of oxidation achievable with the permeability test apparatus, coal permeability dropped over time. While the magnitude of the reduction was not large for low oxidation magnitudes, the impact on permeability was demonstrated. A weathering index was developed as part of the study to provide a quantitative basis for assessing the weathered state of coal samples. The index employed changes to Fourier Transform Infrared Spectroscopy (FTIR) spectra to define the state of weathering. To assess the rate and magnitude of weathering of coal through oxidation an autoclave was used to artificially weather brown coal. Fourier Transform Infrared Spectroscopy and Gas Chromatography used to analyse the results. As for the permeability testing the autoclave experiments could not be run for sufficient time to progress to complete weathering by oxidation. Nevertheless the principles of the test and the equipment specifications were developed so that they could be used in future to complete the determination of weathering rates. The research has demonstrated the importance of understanding coal weathering at the upper boundary of a rehabilitated coal surface to the potential for cover mass movements due to sliding at the coal cover interface.
- Description: Masters by Research
- Authors: Allen, Tristan
- Date: 2018
- Type: Text , Thesis , Masters
- Full Text:
- Description: The goal of the research is to quantify coal properties that may affect the processes and controls governing rehabilitated brown coal mine surface mass movements. The research investigates weathering of coal and assesses the difference in strength characteristics between fresh and weathered coal. In addition to quantifying the mechanical properties of coal surfaces in a rehabilitated slope, permeability changes due to weathering of coal are also investigated. Changes in coal strength influence sliding resistance. Changes in coal permeability impact pore pressures above the coal surface, which may also affect sliding resistance on the coal – cover interface. To assess these issues, direct and residual shear tests were used to investigate the changes in shear strength due to weathering at low normal stresses applicable to shallow cover materials. Testing was undertaken with abrasive surfaces to simulate sliding on the contact coal surface beneath cover materials assuming that the cover material is stronger than the coal. The roughness of the abrasive surface proved to be unimportant for large strain shear strength. The shear strength for coal with different weathering and normal effective stresses was examined. Coal cohesion was found to be low, but some rebinding of coal would occur with time. A coal residual friction angle of 39.1 and 37.0 degrees was found for the unsaturated and saturated tested coal respectively. Permeability tests using oxygenated water were undertaken to investigate changes to brown coal permeability as a result of weathering. Even with low levels of oxidation achievable with the permeability test apparatus, coal permeability dropped over time. While the magnitude of the reduction was not large for low oxidation magnitudes, the impact on permeability was demonstrated. A weathering index was developed as part of the study to provide a quantitative basis for assessing the weathered state of coal samples. The index employed changes to Fourier Transform Infrared Spectroscopy (FTIR) spectra to define the state of weathering. To assess the rate and magnitude of weathering of coal through oxidation an autoclave was used to artificially weather brown coal. Fourier Transform Infrared Spectroscopy and Gas Chromatography used to analyse the results. As for the permeability testing the autoclave experiments could not be run for sufficient time to progress to complete weathering by oxidation. Nevertheless the principles of the test and the equipment specifications were developed so that they could be used in future to complete the determination of weathering rates. The research has demonstrated the importance of understanding coal weathering at the upper boundary of a rehabilitated coal surface to the potential for cover mass movements due to sliding at the coal cover interface.
- Description: Masters by Research
The competing discourses of workplace health
- Authors: Allender, Steven
- Date: 2001
- Type: Text , Thesis , PhD
- Full Text:
- Description: "This study provides a postcritical analysis of the discourses on workplace health, using data gathered with information technology company Labyrinth Computing."
- Description: Doctor of Philosophy
- Authors: Allender, Steven
- Date: 2001
- Type: Text , Thesis , PhD
- Full Text:
- Description: "This study provides a postcritical analysis of the discourses on workplace health, using data gathered with information technology company Labyrinth Computing."
- Description: Doctor of Philosophy
Fermentation and the microbial community of Japanese koji and miso : a review
- Allwood, Joanne, Wakeling, Lara, Bean, David
- Authors: Allwood, Joanne , Wakeling, Lara , Bean, David
- Date: 2021
- Type: Text , Journal article , Review
- Relation: Journal of Food Science Vol. 86, no. 6 (2021), p. 2194-2207
- Full Text:
- Reviewed:
- Description: Abstract: Miso is a well-known traditional Japanese fermented food, with a characteristic savory flavor and aroma, known predominately as the seasoning in miso soup. Miso production involves a two-stage fermentation, where first a mold, such as Aspergillus oryzae, is inoculated onto a substrate to make koji. A subsequent fermentation, this time by bacteria and yeast, occurs when the koji is added to a salt and soybean mash, with the miso left to ferment for up to 2 years. The microbial community of miso is considered essential to the development of the unique taste, texture, and nutritional profile of miso. Despite the importance of microorganisms in the production of miso, very little research has been undertaken to characterize and describe the microbial process. In this review, we provide an overview of the two-stage fermentation process, describe what is currently known about the microbial communities involved and consider any potential health benefits associated with the consumption of miso, along with food safety concerns. As the popularity of miso continues to expand globally and is produced under new environmental conditions, understanding the microbiological processes involved will assist to ensure that global production of miso is safe as well as delicious. © 2021 Institute of Food Technologists®
- Authors: Allwood, Joanne , Wakeling, Lara , Bean, David
- Date: 2021
- Type: Text , Journal article , Review
- Relation: Journal of Food Science Vol. 86, no. 6 (2021), p. 2194-2207
- Full Text:
- Reviewed:
- Description: Abstract: Miso is a well-known traditional Japanese fermented food, with a characteristic savory flavor and aroma, known predominately as the seasoning in miso soup. Miso production involves a two-stage fermentation, where first a mold, such as Aspergillus oryzae, is inoculated onto a substrate to make koji. A subsequent fermentation, this time by bacteria and yeast, occurs when the koji is added to a salt and soybean mash, with the miso left to ferment for up to 2 years. The microbial community of miso is considered essential to the development of the unique taste, texture, and nutritional profile of miso. Despite the importance of microorganisms in the production of miso, very little research has been undertaken to characterize and describe the microbial process. In this review, we provide an overview of the two-stage fermentation process, describe what is currently known about the microbial communities involved and consider any potential health benefits associated with the consumption of miso, along with food safety concerns. As the popularity of miso continues to expand globally and is produced under new environmental conditions, understanding the microbiological processes involved will assist to ensure that global production of miso is safe as well as delicious. © 2021 Institute of Food Technologists®
Food safety considerations in the production of traditional fermented products : Japanese rice koji and miso
- Allwood, Joanne, Wakeling, Lara, Post, Laurie, Bean, David
- Authors: Allwood, Joanne , Wakeling, Lara , Post, Laurie , Bean, David
- Date: 2023
- Type: Text , Journal article , Review
- Relation: Journal of Food Safety Vol. 43, no. 4 (2023), p.
- Full Text:
- Reviewed:
- Description: While established in Asia, rice koji and miso are fermented foods that are becoming more popular in western countries. They have been shown to contain a variety of microorganisms, consisting of bacteria, yeasts, and fungal species. Many contemporary miso varieties are not pasteurized as consumers are looking for more natural products, and/or have the desire to consume fermented foods containing live microorganisms. While correctly prepared fermented foods are rarely associated with food safety outbreaks, incidences have been recorded. On these occasions, pathogenic, or spoilage microorganisms were introduced into the products from external sources such as the raw material or the processing environment. Consequently, hygiene and fermentation conditions need to be carefully monitored to ensure food safety. Furthermore, many of the production steps during koji and miso manufacture do not fit into contemporary food safety guidelines for foods. Although pH is a required food safety hurdle for fermented foods, this does not apply to nonacidic foods such as koji or miso. This review focuses on control of microbial pathogens and discusses the processes of miso fermentation, and how fermentation of rice koji and miso fits with current food safety hurdles in western countries. © 2023 The Authors. Journal of Food Safety published by Wiley Periodicals LLC.
- Authors: Allwood, Joanne , Wakeling, Lara , Post, Laurie , Bean, David
- Date: 2023
- Type: Text , Journal article , Review
- Relation: Journal of Food Safety Vol. 43, no. 4 (2023), p.
- Full Text:
- Reviewed:
- Description: While established in Asia, rice koji and miso are fermented foods that are becoming more popular in western countries. They have been shown to contain a variety of microorganisms, consisting of bacteria, yeasts, and fungal species. Many contemporary miso varieties are not pasteurized as consumers are looking for more natural products, and/or have the desire to consume fermented foods containing live microorganisms. While correctly prepared fermented foods are rarely associated with food safety outbreaks, incidences have been recorded. On these occasions, pathogenic, or spoilage microorganisms were introduced into the products from external sources such as the raw material or the processing environment. Consequently, hygiene and fermentation conditions need to be carefully monitored to ensure food safety. Furthermore, many of the production steps during koji and miso manufacture do not fit into contemporary food safety guidelines for foods. Although pH is a required food safety hurdle for fermented foods, this does not apply to nonacidic foods such as koji or miso. This review focuses on control of microbial pathogens and discusses the processes of miso fermentation, and how fermentation of rice koji and miso fits with current food safety hurdles in western countries. © 2023 The Authors. Journal of Food Safety published by Wiley Periodicals LLC.
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.
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.
- 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).
- 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).
Differential associations of hypoxia, sleep fragmentation, and depressive symptoms with cognitive dysfunction in obstructive sleep apnea
- Alomri, Ridwan, Kennedy, Gerard, Wali, Siraj, Ahejaili, Faris, Robinson, Stephen
- Authors: Alomri, Ridwan , Kennedy, Gerard , Wali, Siraj , Ahejaili, Faris , Robinson, Stephen
- Date: 2021
- Type: Text , Journal article
- Relation: Sleep Vol. 44, no. 4 (2021), p.
- Full Text:
- Reviewed:
- Description: Obstructive sleep apnea (OSA) is characterized by recurrent episodes of partial or complete cessation of breathing during sleep and increased effort to breathe. This study examined patients who underwent overnight polysomnographic studies in a major sleep laboratory in Saudi Arabia. The study aimed to determine the extent to which intermittent hypoxia, sleep disruption, and depressive symptoms are independently associated with cognitive impairments in OSA. In the sample of 90 participants, 14 had no OSA, 30 mild OSA, 23 moderate OSA, and 23 severe OSA. The findings revealed that hypoxia and sleep fragmentation are independently associated with impairments of sustained attention and reaction time (RT). Sleep fragmentation, but not hypoxia, was independently associated with impairments in visuospatial deficits. Depressive symptoms were independently associated with impairments in the domains of sustained attention, RT, visuospatial ability, and semantic and episodic autobiographical memories. Since the depressive symptoms are independent of hypoxia and sleep fragmentation, effective reversal of cognitive impairment in OSA may require treatment interventions that target each of these factors. © Sleep Research Society 2020. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.
- Authors: Alomri, Ridwan , Kennedy, Gerard , Wali, Siraj , Ahejaili, Faris , Robinson, Stephen
- Date: 2021
- Type: Text , Journal article
- Relation: Sleep Vol. 44, no. 4 (2021), p.
- Full Text:
- Reviewed:
- Description: Obstructive sleep apnea (OSA) is characterized by recurrent episodes of partial or complete cessation of breathing during sleep and increased effort to breathe. This study examined patients who underwent overnight polysomnographic studies in a major sleep laboratory in Saudi Arabia. The study aimed to determine the extent to which intermittent hypoxia, sleep disruption, and depressive symptoms are independently associated with cognitive impairments in OSA. In the sample of 90 participants, 14 had no OSA, 30 mild OSA, 23 moderate OSA, and 23 severe OSA. The findings revealed that hypoxia and sleep fragmentation are independently associated with impairments of sustained attention and reaction time (RT). Sleep fragmentation, but not hypoxia, was independently associated with impairments in visuospatial deficits. Depressive symptoms were independently associated with impairments in the domains of sustained attention, RT, visuospatial ability, and semantic and episodic autobiographical memories. Since the depressive symptoms are independent of hypoxia and sleep fragmentation, effective reversal of cognitive impairment in OSA may require treatment interventions that target each of these factors. © Sleep Research Society 2020. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.