LPV-based quality interpretations on modeling and control of diabetes

In this study we introduce different novel interpretations in the case of Linear Parameter Varying (LPV) methodology, which are directly usable in modeling and control design in diabetes research. These novel interpretations are based on the parameter vectors of the LPV parameter space. The theoretical solutions are demonstrated on a simple, known Type 1 Diabetes Model used in intensive care

Evaluation of T1 relaxation time in prostate cancer and benign prostate tissue using a Modified Look-Locker inversion recovery sequence

Purpose of this study was to evaluate the diagnostic performance of T1 relaxation time (T1) for differentiating prostate cancer (PCa) from benign tissue as well as high- from low-grade PCa. Twenty-three patients with suspicion for PCa were included in this prospective study. 3 T MRI including a Modified Look-Locker inversion recovery sequence was acquired. Subsequent targeted and systematic prostate biopsy served as a reference standard. T1 and apparent diffusion coefficient (ADC) value in PCa and reference regions without malignancy as well as high- and low-grade PCa were compared using the Mann-Whitney U test. The performance of T1, ADC value, and a combination of both to differentiate PCa and reference regions was assessed by receiver operating characteristic (ROC) analysis. T1 and ADC value were lower in PCa compared to reference regions in the peripheral and transition zone (p < 0.001). ROC analysis revealed high AUCs for T1 (0.92; 95%-CI, 0.87-0.98) and ADC value (0.97; 95%-CI, 0.94 to 1.0) when differentiating PCa and reference regions. A combination of T1 and ADC value yielded an even higher AUC. The difference was statistically significant comparing it to the AUC for ADC value alone (p = 0.02). No significant differences were found between high- and low-grade PCa for T1 (p = 0.31) and ADC value (p = 0.8). T1 relaxation time differs significantly between PCa and benign prostate tissue with lower T1 in PCa. It could represent an imaging biomarker for PCa

Investigation of the TP-based modeling possibility of a nonlinear ICU diabetes model

In-silico modeling is an important part of biomedical engineering. Advanced controllers providing high quality control can be validated through it checking if the available mathematical model of the given biomedical process produces the desired output. However, due to high patient variability the advanced linear control methods applied on linearized models could produce several distortions compared to the original nonlinear models; hence, these errors should be reduced. Hierarchical control strategies could be a possibility or from modeling point of view using different control-oriented modeling methodologies. Linear Parameter Varying (LPV) approaches with Linear Matrix Inequality (LMI) based modeling and controller design represent one choice. In this paper, we investigate their generalized extension, the Tensor Product (TP) model transformation demonstrated on diabetes modeling. In concrete, the type 1 diabetes modeling on Intensive Care Units (ICU) is envisaged. The achieved results will be used for TP transformation based controller design in our later wor

Exploring the psychological rewards of a familiar semirural landscape: connecting to local nature through a mindful approach

This study analyses a 53,000 word diary of a year engaging with nature through over 200 trips to a semi-rural landscape. Thematic analysis revealed two themes; the transition from observer to nature connectedness and the ways in which the natural environment was experienced once a connection was made. These themes are discussed in relation to theories that seek to explain the positive effect of nature and nature connectedness. The findings are important as they suggest that repeated engagement with local semi-rural countryside can lead to a mindful approach and psychological rewards that do not require travel into the wilderness. The work informs further research into outcomes and processes of nature based interventions such as: trip frequency, duration and diary keeping

High-pressure polymorphism in pyridine

Single crystals of the high-pressure phases II and III of pyridine have been obtained by in situ crystallization at 1.09 and 1.69 GPa, revealing the crystal structure of phase III for the first time using X-ray diffraction. Phase II crystallizes in P212121 with Z' = 1 and phase III in P41212 with Z' = ½. Neutron powder diffraction experiments using pyridine-d5 establish approximate equations of state of both phases. The space group and unit-cell dimensions of phase III are similar to the structures of other simple compounds with C 2v molecular symmetry, and the phase becomes stable at high pressure because it is topologically close-packed, resulting in a lower molar volume than the topologically body-centred cubic phase II. Phases II and III have been observed previously by Raman spectroscopy, but have been mis-identified or inconsistently named. Raman spectra collected on the same samples as used in the X-ray experiments establish the vibrational characteristics of both phases unambiguously. The pyridine molecules interact in both phases through CH⋯π and CH⋯N interactions. The nature of individual contacts is preserved through the phase transition between phases III and II, which occurs on decompression. A combination of rigid-body symmetry mode analysis and density functional theory calculations enables the soft vibrational lattice mode which governs the transformation to be identified

Effect of Model, Observer and Their Interaction on State and Disturbance Estimation in Artificial Pancreas: An In-Silico Study

The state and disturbance estimations are an indispensable part of the state-of-the-art model-based controllers as related to the artificial pancreas, supporting the decision-making and self-tuning of the algorithms. They are not just important when state-feedback kind of controller structure is applied, but also play a crucial role in the estimation of, for example, the amount of the acting drug (insulin) in blood or meal intake estimation which has determining role in the short and long term effectivity of the given therapy. This information is also important for physicians to support them in knowledge-based decision-making to be sure a given therapy or device works well. This article compares three observers &#x2013; a linear-parameter-varying (LPV) dual Kalman filter (KF), a LPV joint KF, and a nonlinear sliding mode observer (NSMO) &#x2013; designed with two individualized models &#x2013; Hovorka and Identifiable Virtual Patient model (IVP). The article also statistically quantifies the effect of the observer algorithm and model structure on the accuracy of the estimation of plasma insulin, rate of glucose appearance, and glucose. Data for the analysis was generated by the UVa-Padova simulator. Results indicated that, for the rate of glucose appearance and the plasma insulin, the type of model and the observer structure explain less than 10&#x0025; of the variability in the error, while the inter-patient variability contributes to the error more than 50&#x0025;. This reveals a limiting factor in the estimation accuracy that might be improved by model parameter adaptation

Antecedents and outcomes of consumer environmentally friendly attitudes and behaviour

With the intensification of problems relating to the environment, a growing number of consumers are becoming more ecologically conscious in their preferences and purchases of goods. This paper presents the results of a study conducted among 500 Cypriot consumers, focusing on the factors that shape consumer environmental attitudes and behaviour, as well as on the resulting outcomes. The findings confirmed that both the inward and outward environmental attitudes of a consumer are positively influenced by his/her degree of collectivism, long-term orientation, political involvement, deontology, and law obedience, but have no connection with liberalism. The adoption of an inward environmental attitude was also found to be conducive to green purchasing behaviour that ultimately leads to high product satisfaction. On the other hand, an outward environmental attitude facilitates the adoption of a general environmental behaviour, which is responsible for greater satisfaction with life. The findings of the study have important implications for shaping effective company offerings to consumers in target markets, as well as formulating appropriate policies at the governmental level to enhance environmental sensitivity among citizens