title: Predicting glucose level with an adapted branch predictor

authors: Koutny, Tomas

subjects: computer science

abstract: Background and objective
Diabetes mellitus manifests as prolonged elevated blood glucose levels resulting from impaired insulin production. Such high glucose levels over a long period of time damage multiple internal organs. To mitigate this condition, researchers and engineers have developed the closed loop artificial pancreas consisting of a continuous glucose monitor and an insulin pump connected via a microcontroller or smartphone. A problem, however, is how to accurately predict short term future glucose levels in order to exert efficient glucose-level control. Much work in the literature focuses on least prediction error as a key metric and therefore pursues complex prediction methods such a deep learning. Such an approach neglects other important and significant design issues such as method complexity (impacting interpretability and safety), hardware requirements for low-power devices such as the insulin pump, the required amount of input data for training (potentially rendering the method infeasible for new patients), and the fact that very small improvements in accuracy may not have significant clinical benefit.

Methods
We propose a novel low-complexity, explainable blood glucose prediction method derived from the Intel P6 branch predictor algorithm. We use Meta-Differential Evolution to determine predictor parameters on training data splits of the benchmark datasets we use. A comparison is made between our new algorithm and a state-of-the-art deep-learning method for blood glucose level prediction.

Results
To evaluate the new method, the Blood Glucose Level Prediction Challenge benchmark dataset is utilised. On the official test data split after training, the state-of-the-art deep learning method predicted glucose levels 30 min ahead of current time with 96.3% of predicted glucose levels having relative error less than 30% (which is equivalent to the safe zone of the Surveillance Error Grid). Our simpler, interpretable approach prolonged the prediction horizon by another 5 min with 95.8% of predicted glucose levels of all patients having relative error less than 30%.

Conclusions
When considering predictive performance as assessed using the Blood Glucose Level Prediction Challenge benchmark dataset and Surveillance Error Grid metrics, we found that the new algorithm delivered comparable predictive accuracy performance, while operating only on the glucose-level signal with considerably less computational complexity.

text: Predicting glucose level with an adapted branch predictor Background and objective
Diabetes mellitus manifests as prolonged elevated blood glucose levels resulting from impaired insulin production. Such high glucose levels over a long period of time damage multiple internal organs. To mitigate this condition, researchers and engineers have developed the closed loop artificial pancreas consisting of a continuous glucose monitor and an insulin pump connected via a microcontroller or smartphone. A problem, however, is how to accurately predict short term future glucose levels in order to exert efficient glucose-level control. Much work in the literature focuses on least prediction error as a key metric and therefore pursues complex prediction methods such a deep learning. Such an approach neglects other important and significant design issues such as method complexity (impacting interpretability and safety), hardware requirements for low-power devices such as the insulin pump, the required amount of input data for training (potentially rendering the method infeasible for new patients), and the fact that very small improvements in accuracy may not have significant clinical benefit.

Methods
We propose a novel low-complexity, explainable blood glucose prediction method derived from the Intel P6 branch predictor algorithm. We use Meta-Differential Evolution to determine predictor parameters on training data splits of the benchmark datasets we use. A comparison is made between our new algorithm and a state-of-the-art deep-learning method for blood glucose level prediction.

Results
To evaluate the new method, the Blood Glucose Level Prediction Challenge benchmark dataset is utilised. On the official test data split after training, the state-of-the-art deep learning method predicted glucose levels 30 min ahead of current time with 96.3% of predicted glucose levels having relative error less than 30% (which is equivalent to the safe zone of the Surveillance Error Grid). Our simpler, interpretable approach prolonged the prediction horizon by another 5 min with 95.8% of predicted glucose levels of all patients having relative error less than 30%.

Conclusions
When considering predictive performance as assessed using the Blood Glucose Level Prediction Challenge benchmark dataset and Surveillance Error Grid metrics, we found that the new algorithm delivered comparable predictive accuracy performance, while operating only on the glucose-level signal with considerably less computational complexity.

year: 2022

title: Some structural and photochemical studies in triterpenoids

authors: Zhu, Julie Hehui

abstract: This thesis describes the photochemical behaviour of 22-hydroxyhopan-7-one, hop-22(29)-en-7-one, 22-hydroxyhopan-15-one, hop-21-en-15-one, hop-22(29)-en-15-one, hopan-15-one and 21α-H-hopan-15-one in different solvents, and the isolation and structural elucidation of a new stictane and a new flavicane triterpene from the New Zealand lichen Pseudocyphellaria colensoi.

Photolysis of 22-hydroxyhopan-7-one in benzene-methanol was reinvestigated and confirmed to afford methyl 22-hydroxy-7,8-secohopan-7-oate. The photochemical behaviour of 22-hydroxyhopan-7-one and hop-22(29)-en-7-one in the presence of benzene alone, and in benzene-isopropanol, were also investigated.

Photolysis of hop-22(29)-en-7-one in benzene-methanol afforded methyl 7,8-secohop-22(29)en-7-oate while photolysis of 22-hydroxyhopan-7-one in methanol-isopropanol afforded isopropyl 22-hydroxy-7,8-secohopan-7-oate. Photolysis of 22-hydroxy-hopan-7-one in benzene alone afforded mainly unreacted starting material and some minor products, one of which was believed to be 22-hydroxy-7,8-secohop-8(26)-en-7-al.

The stereochemistry at C-8 for these compounds was determined by analyses of ROESY or NOESY NMR spectral data which showed the C-8 methyl group to be β-oriented, and indicated that photochemical rearrangement reactions proceeded with retention of configuration at C-8. Modelling analyses indicated the 8β-methyl secoesters to have lower energy than the corresponding 8α-methyl isomers.

Complete assignments of the ¹H and ¹³C NMR signals of methyl 22-hydroxy-7,8-secohopan-7-oate, isopropyl 22-hydroxy-7,8-secohopan-7-oate and methyl 7,8-secohop-22(29)-en-7-oate, were achieved using a combination of one- and two-dimensional NMR techniques.

The three products obtained on photolysis of 22-hydroxyhopan-15-one, in benzene-methanol, benzene-isopropanol, or benzene alone, were identified as 14,15-seco-15,22-O-abeohop-14(27)-en-15α-ol, 14,15-seco-15,22-O-abeohop-14(27)-en-15-one, and 14,15-seco-15,22-O-abeohopa-14(27), 15-diene, respectively. These products can be envisaged as arising from participation of the 22-hydroxyl group in the photoreaction pathway, after the initial formation of a 14,15-secoaldehyde.

Photolysis of hop-21-en-15-one in benzene-methanol afforded 14,15-secohopa-14(27),21-dien-15-al as the major product, while photolysis of hop-22(29)-en-15-one gave a complex mixture of products which was not further investigated. Photolysis of hopan-15-one yielded two products which were identified as the isomeric alcohols, 14,15-seco-15,22-abeohop-14(27)-en-15α-ol and 14,15-seco-15,22-abeohop-14(27)-en-15β-ol. Photolysis of 21α-H-hopan-15-one afforded two products, which were identified as methyl 14α,21α-H-14,15-secohopan-15-oate and methyl 21α-H-14,15-secohopan-15-oate.

Complete assignments of the ¹H and ¹³C NMR signals of the foregoing series of 15-oxohopanoid photoreaction products, and where appropriate the stereochemistry at C-14 and/or C-15, were achieved using a combination of one- and two-dimensional ROESY, NOESY, COSY, HMBC, and HSQC NMR spectral data, and molecular modelling results.

The results of the series of 15-oxohopanoid photoreactions can be interpreted indicating that in the presence of an α-oriented side chain (ie 22-hydroxyisopropyl group or isopropyl group) at C-21, the photoreaction proceeds with hydrogen transfer via an eight-membered transition state to afford a secoaldehyde or 14,15-secohop-4(27)-en-15-al which then affords 14,15-seco-15,22-O-abeohop-14(27)-en-15α-ol via participation of the 22-hydroxyl group and related analogues. Similarly the isomeric alcohols, 14,15-seco-15,22-abeohop-14(27)-en-15α-ol and 14,15-seco-15,22-abeohop-14(27)-en-15β-ol, obtained on photolysis of hopan-15-one can be viewed as 22-H participation products. On the other hand photolysis of a 15-oxohopanoid possessing a β-oriented side chain at C-21 was found to proceed with hydrogen transfer via a six-membered transition state to afford a pair of epimeric 14,15-secoesters.

A new stictane triterpene, and a new flavicane triterpene were isolated from extracts of the New Zealand lichen Pseudocyphellaria colensoi, and identified by analyses of mass spectral and one- and two-dimensional NMR spectral data to be 3α,6β,22α-triacetoxystictane and 22-hydroxyflavicano-25,3β-lactone, respectively. Complete assignments of the ¹H ¹³C NMR signals of the new triterpenes, and revisions to previously reported ¹³C NMR signal assignments for 22α-hydroxystictano-25,3β-lactone are reported.

text: Some structural and photochemical studies in triterpenoids This thesis describes the photochemical behaviour of 22-hydroxyhopan-7-one, hop-22(29)-en-7-one, 22-hydroxyhopan-15-one, hop-21-en-15-one, hop-22(29)-en-15-one, hopan-15-one and 21α-H-hopan-15-one in different solvents, and the isolation and structural elucidation of a new stictane and a new flavicane triterpene from the New Zealand lichen Pseudocyphellaria colensoi.

Photolysis of 22-hydroxyhopan-7-one in benzene-methanol was reinvestigated and confirmed to afford methyl 22-hydroxy-7,8-secohopan-7-oate. The photochemical behaviour of 22-hydroxyhopan-7-one and hop-22(29)-en-7-one in the presence of benzene alone, and in benzene-isopropanol, were also investigated.

Photolysis of hop-22(29)-en-7-one in benzene-methanol afforded methyl 7,8-secohop-22(29)en-7-oate while photolysis of 22-hydroxyhopan-7-one in methanol-isopropanol afforded isopropyl 22-hydroxy-7,8-secohopan-7-oate. Photolysis of 22-hydroxy-hopan-7-one in benzene alone afforded mainly unreacted starting material and some minor products, one of which was believed to be 22-hydroxy-7,8-secohop-8(26)-en-7-al.

The stereochemistry at C-8 for these compounds was determined by analyses of ROESY or NOESY NMR spectral data which showed the C-8 methyl group to be β-oriented, and indicated that photochemical rearrangement reactions proceeded with retention of configuration at C-8. Modelling analyses indicated the 8β-methyl secoesters to have lower energy than the corresponding 8α-methyl isomers.

Complete assignments of the ¹H and ¹³C NMR signals of methyl 22-hydroxy-7,8-secohopan-7-oate, isopropyl 22-hydroxy-7,8-secohopan-7-oate and methyl 7,8-secohop-22(29)-en-7-oate, were achieved using a combination of one- and two-dimensional NMR techniques.

The three products obtained on photolysis of 22-hydroxyhopan-15-one, in benzene-methanol, benzene-isopropanol, or benzene alone, were identified as 14,15-seco-15,22-O-abeohop-14(27)-en-15α-ol, 14,15-seco-15,22-O-abeohop-14(27)-en-15-one, and 14,15-seco-15,22-O-abeohopa-14(27), 15-diene, respectively. These products can be envisaged as arising from participation of the 22-hydroxyl group in the photoreaction pathway, after the initial formation of a 14,15-secoaldehyde.

Photolysis of hop-21-en-15-one in benzene-methanol afforded 14,15-secohopa-14(27),21-dien-15-al as the major product, while photolysis of hop-22(29)-en-15-one gave a complex mixture of products which was not further investigated. Photolysis of hopan-15-one yielded two products which were identified as the isomeric alcohols, 14,15-seco-15,22-abeohop-14(27)-en-15α-ol and 14,15-seco-15,22-abeohop-14(27)-en-15β-ol. Photolysis of 21α-H-hopan-15-one afforded two products, which were identified as methyl 14α,21α-H-14,15-secohopan-15-oate and methyl 21α-H-14,15-secohopan-15-oate.

Complete assignments of the ¹H and ¹³C NMR signals of the foregoing series of 15-oxohopanoid photoreaction products, and where appropriate the stereochemistry at C-14 and/or C-15, were achieved using a combination of one- and two-dimensional ROESY, NOESY, COSY, HMBC, and HSQC NMR spectral data, and molecular modelling results.

The results of the series of 15-oxohopanoid photoreactions can be interpreted indicating that in the presence of an α-oriented side chain (ie 22-hydroxyisopropyl group or isopropyl group) at C-21, the photoreaction proceeds with hydrogen transfer via an eight-membered transition state to afford a secoaldehyde or 14,15-secohop-4(27)-en-15-al which then affords 14,15-seco-15,22-O-abeohop-14(27)-en-15α-ol via participation of the 22-hydroxyl group and related analogues. Similarly the isomeric alcohols, 14,15-seco-15,22-abeohop-14(27)-en-15α-ol and 14,15-seco-15,22-abeohop-14(27)-en-15β-ol, obtained on photolysis of hopan-15-one can be viewed as 22-H participation products. On the other hand photolysis of a 15-oxohopanoid possessing a β-oriented side chain at C-21 was found to proceed with hydrogen transfer via a six-membered transition state to afford a pair of epimeric 14,15-secoesters.

A new stictane triterpene, and a new flavicane triterpene were isolated from extracts of the New Zealand lichen Pseudocyphellaria colensoi, and identified by analyses of mass spectral and one- and two-dimensional NMR spectral data to be 3α,6β,22α-triacetoxystictane and 22-hydroxyflavicano-25,3β-lactone, respectively. Complete assignments of the ¹H ¹³C NMR signals of the new triterpenes, and revisions to previously reported ¹³C NMR signal assignments for 22α-hydroxystictano-25,3β-lactone are reported.

year: 2000

title: Talking About Race and Positionality in Psychology: Asians as Tangata Tiriti

authors: Tan, Kyle K. H.

subjects: tangata whenua

abstract: The article discusses the dominance of Western, educated, industrialized, rich, and democratic (WEIRD) perspectives in the field of psychology in Aotearoa New Zealand. This has resulted in a racial hierarchy of knowledge, with Indigenous and culturally diverse epistemologies marginalized. The lack of diversity in the curriculum and the limited representation of non-Pākehā (non-New Zealand European) psychologists in the country have led to calls for a more inclusive environment.

The first perspective proposed is to understand Asians as a racialized group with diverse experiences. Asians in Aotearoa come from various backgrounds and face different degrees of racism and acculturation. The notion of 'Asian' may be used to marginalize the interests of Māori, perpetuating institutional racism. The concept of 'Asianisations' describes different forms of racial marginalization experienced by Asians in the country.

The second perspective emphasizes the positionality of Asians as tangata Tiriti (people of the Treaty). Te Tiriti o Waitangi, the Treaty between the British Crown and Māori chiefs, is seen as granting tangata Tiriti equal rights and privileges alongside Pākehā and Māori. As tangata Tiriti, Asians have a responsibility to uphold Tiriti principles, which include partnership, active protection, equity, and options to address Māori inequities. Asian psychologists can engage in culturally safe care for Māori clients and collaborate with and empower Māori leadership in research.

The article highlights the need for Asian psychologists to reflect on their positionality, power structures, and biases within the discipline and society. It encourages them to challenge the dominance of WEIRD psychology and work towards decolonizing the field. By doing so, they can contribute to the flourishing of Kaupapa Māori psychology and develop culturally informed practices that draw on the richness of Asian cultures.

text: Talking About Race and Positionality in Psychology: Asians as Tangata Tiriti The article discusses the dominance of Western, educated, industrialized, rich, and democratic (WEIRD) perspectives in the field of psychology in Aotearoa New Zealand. This has resulted in a racial hierarchy of knowledge, with Indigenous and culturally diverse epistemologies marginalized. The lack of diversity in the curriculum and the limited representation of non-Pākehā (non-New Zealand European) psychologists in the country have led to calls for a more inclusive environment.

The first perspective proposed is to understand Asians as a racialized group with diverse experiences. Asians in Aotearoa come from various backgrounds and face different degrees of racism and acculturation. The notion of 'Asian' may be used to marginalize the interests of Māori, perpetuating institutional racism. The concept of 'Asianisations' describes different forms of racial marginalization experienced by Asians in the country.

The second perspective emphasizes the positionality of Asians as tangata Tiriti (people of the Treaty). Te Tiriti o Waitangi, the Treaty between the British Crown and Māori chiefs, is seen as granting tangata Tiriti equal rights and privileges alongside Pākehā and Māori. As tangata Tiriti, Asians have a responsibility to uphold Tiriti principles, which include partnership, active protection, equity, and options to address Māori inequities. Asian psychologists can engage in culturally safe care for Māori clients and collaborate with and empower Māori leadership in research.

The article highlights the need for Asian psychologists to reflect on their positionality, power structures, and biases within the discipline and society. It encourages them to challenge the dominance of WEIRD psychology and work towards decolonizing the field. By doing so, they can contribute to the flourishing of Kaupapa Māori psychology and develop culturally informed practices that draw on the richness of Asian cultures.

year: 2023-07-24