Selection of Process Conditions for High Pressure Pasteurization of Sea Buckthorn Juice Retaining High Antioxidant Activity

Sea buckthorn berries juice is a nutritious beverage, rich in vitamin C and carotenoids with high antioxidant activity. The main requirements for a freshly squeezed sea buckthorn juice production are the cloud stability and antioxidant activity retention after processing. Appropriate process technologies and conditions have to be applied in order to inactivate pectin methyl esterase (PME), responsible for cloud loss, while maintaining the nutritional characteristics and antioxidant activity of the juice. The objectives of the present work were to study and model the effect of thermal treatment and high pressure (HP) processing on the inactivation kinetics of endogenous PME and on total antioxidant activity alteration. Thermal treatment significantly affected PME inactivation and residual antioxidant activity. Processing even at mild process conditions (60 °C for 1 min) resulted in 2.5-fold antioxidant activity reduction and 50 % PME inactivation compared to untreated sample. Pressure and temperature acted synergistically for PME inactivation that followed first-order kinetics with a residual PME activity at all pressure–temperature combinations used (200–600 MPa and 25–35 °C). The effect of temperature and pressure on the inactivation rate constants was expressed through the activation energy and activation volume, respectively. Values of 163 kJ/mol and ?17 mL/mol at reference pressure of 600 MPa and reference temperature of 35 °C were estimated, respectively. Antioxidant activity of the samples was expressed through the determination of the effective concentration (EC₅₀). A slight increase in sea buckthorn antioxidant activity when applying pressures (200–600 MPa) at ambient temperature (25 °C) was observed compared to the corresponding value of untreated juice. Processing at higher temperatures did not significantly alter the total antioxidant activity of sea buckthorn juice. For sample treated at 600 MPa–35 °C for 5 min, a 5 % reduction of total antioxidant activity was observed. These conditions are proposed as effective process conditions for sea buckthorn juice cold pasteurization, based on the higher antioxidant activity retention and simultaneous PME inactivation.     

Mixed logit analysis of safety-belt use in single- and multi-occupant vehicles

In this paper we demonstrate a modeling approach that can be used to better understand the use of safety belts in single- and multi-occupant vehicles, and the effect that vehicle, roadway and occupant characteristics have on usage rates. Using data from a roadside observational survey of safety-belt use in Indiana, a mixed (random parameters) logit model is estimated. Potentially interrelated choices of safety-belt use by drivers and front-seat passengers are examined. The approach we use also allows for the possibility that estimated model parameters can vary randomly across vehicle occupants to account for unobserved effects potentially relating to roadway characteristics, vehicle attributes, and driver behavior. Estimation findings indicate that the choices of safety-belt use involve a complex interaction of factors and that the effect of these factors can vary significantly across the population. Our results show that the mixed logit model can provide a much fuller understanding of the interaction of the numerous variables which correlate with safety-belt use than traditional discrete-outcome modeling approaches.     

Integrating Diffuse and Concentrated Recharge in Karst Models

Distributed parameter models of mature karst aquifers need to take into consideration both the dual character of flow in the saturated zone and the heterogeneous infiltration conditions. Usually, in the modeling of unconfined aquifers, recharge due to infiltration is considered as uniformly distributed over the entire domain. The present study evaluates the contribution of distinct infiltration zones and examines different hypotheses on the spatial distribution of recharge zones. The applied methodology comprises two parts: i) the development of a 3D transient model and ii) the development and examination of different scenarios on the spatial distribution of recharge. The model is developed using the finite element code FEFLOW which allows for the integration of discrete features such as channels in a porous matrix. The scenarios for the spatial distribution of the recharge zones describe three hypotheses. In the first scenario, recharge is exclusively introduced through faulted zones. In the second scenario, the entire model domain receives the recharge. In the third scenario, recharge is distributed in sub-areas selected based on geomorphological and hydrogeological criteria. For each scenario, simulation model results for the water table are compared with field measurements and discussed. The derived results indicate that greater model accuracy is achieved for Scenarios 2 and 3. Finally, a forth scenario, designed by combining Scenarios 2 and 3, exhibits the best fitting between simulation results and observation data. The methodology is applied to the karst aquifer of Palaikastro-Chochlakies in Eastern Crete, Greece, for the period 2008–2012.     

Comparative assessment of statistical and machine learning techniques towards estimating the risk of developing type 2 diabetes and cardiovascular complications

The aim of the present study is to comparatively assess the performance of different machine learning and statistical techniques with regard to their ability to estimate the risk of developing type 2 diabetes mellitus (Case 1) and cardiovascular disease complications (Case 2). This is the first work investigating the application of ensembles of artificial neural networks (EANN) towards producing the 5‐year risk of developing type 2 diabetes mellitus and cardiovascular disease as a long‐term diabetes complication. The performance of the proposed models has been comparatively assessed with the performance obtained by applying logistic regression, Bayesian‐based approaches, and decision trees. The models' discrimination and calibration have been evaluated using the classification accuracy (ACC), the area under the curve (AUC) criterion, and the Hosmer–Lemeshow goodness of fit test. The obtained results demonstrate the superiority of the proposed models (EANN) over the other models. In Case 1, EANN with different topologies has achieved high discrimination and good calibration performance (ACC = 80.20%, AUC = 0.849, p value = .886). In Case 2, EANN based on bagging has resulted in good discrimination and calibration performance (ACC = 92.86%, AUC = 0.739, p value = .755).     

FuzzEG: Fuzzy logic for adaptive scenarios in an educational adventure game

Multimedia Tools and Applications - Nowadays, there is an increased interest in using computer games for educational purposes. Educational computer games attempt to increase the students’...     

Alirocumab in a high cardiovascular risk patient on hemodialysis with liver abnormalities

We present a male diabetic type 2 patient on hemodialysis (HD) with high cardiovascular (CVD) risk and hyperlipidemia. The patient was under cholesterol‐lowering therapy with statin and ezetimibe but he was obligated to discontinue due to chronic hepatitis C virus infection. Statins and ezetimibe may exert a potential hepatotoxic effect and for this reason, we attempted to find an alternative treatment to prevent CVD. Given that a potential hepatotoxic effect has not been reported for Abs SPCK9, we administered alirocumab 150 mg every 2 weeks for a total of 8 weeks. Low‐density lipoprotein levels have decreased and no side effects have been observed. In conclusion, alirocumab is a safe and efficient alternative therapy approach for HD patients with high CVD risk and liver abnormalities. We suggest that SPCK 9 inhibitors should be considered as a first line treatment for lowering cholesterol in this specific patient group.     

Comparison of block matching and differential methods for motion analysis of the carotid artery wall from ultrasound images

Motion of the carotid artery wall is important for the quantification of arterial elasticity and contractility and can be estimated with a number of techniques. In this paper, a framework for quantitative evaluation of motion analysis techniques from B-mode ultrasound images is introduced. Six synthetic sequences were produced using 1) a real image corrupted by Gaussian and speckle noise of 25 and 15 dB, and 2) the ultrasound simulation package Field II. In both cases, a mathematical model was used, which simulated the motion of the arterial wall layers and the surrounding tissue, in the radial and longitudinal directions. The performance of four techniques, namely optical flow (OF (HS)), weighted least-squares optical flow (OF (LK(WLS))), block matching (BM), and affine block motion model (ABMM), was investigated in the context of this framework. The average warping indices were lowest for OF (LK(WLS)) (1.75 pixels), slightly higher for ABMM (2.01 pixels), and highest for BM (6.57 pixels) and OF (HS) (11.57 pixels). Due to its superior performance, OF (LK(WLS)) was used to quantify motion of selected regions of the arterial wall in real ultrasound image sequences of the carotid artery. Preliminary results indicate that OF (LK(WLS)) is promising, because it efficiently quantified radial, longitudinal, and shear strains in healthy adults and diseased subjects.     

Polyphenol characterization and encapsulation in β-cyclodextrin of a flavonoid-rich Hypericum perforatum (St John's wort) extract

Purified methanolic extracts of Hypericum perforatum (HP) from Northern Greece were very rich in flavonoids. Among simple polyphenols determined by GC-MS, epicatechin, catechin and quercetin predominated, their concentrations being 118.9 ± 20.6, 8.7 ± 1.4 and 5.8 ± 0.8 mg/g extract. LC-MS analysis revealed that the HP extract was mainly consisted of quercetin glucosides, catechin and quercetin. Among anthocyanins, malvidine was present at 1.96 ± 0.2 mg/g. The 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and the ferric reducing antioxidant power (FRAP) assays showed that the HP extract exerted significant antioxidant activity. The inclusion complex of HP with β-cyclodextrin (β-CD) was prepared by mixing 1:4 mass ratios of its components in aqueous media and subsequent freeze-drying. The encapsulation was verified by differential scanning calorimetry (DSC) and NMR studies, and encapsulation efficiencies were 27.5, 30.0 and 35.0% for catechin, epicatechin and quercetin respectively. DSC after thermal oxidation indicated that the inclusion complex remained intact at temperatures where the free HP extract was oxidized. It is concluded that the encapsulation in β-CD improves the thermal stability of nutraceutical antioxidants present in St John's wort extract, suggesting that the inclusion complex could serve as a flavonoids-rich food supplement or a novel additive to enhance the antioxidant capacity of fresh or thermally processed food.     

An unusual dichromium(II,II) compound bearing di-2-pyridyl ketone oximate ligands and prepared by the ligand-assisted reduction of a trichromium(III,III,III) complex in air

The reaction of the oxide-centred triangular, trichromium(III,III,III) complex [Cr₃O(O₂CCMe₃)₆(H₂O)₃](O₂CCMe₃) with di-2-pyridyl ketone oxime, (py)₂CNOH, in MeCN under aerobic and refluxing conditions yields the pivalate-free, dichromium(II,II) complex [Cr₂{(py)₂CNO}₄] · 2H₂O (1 · 2H₂O). The dinuclear complex can also be prepared by the reaction of [Cr(CO)₆] with (py)₂CNOH in refluxing MeCN/H₂O in air. The two high-spin Cr^II atoms are doubly bridged by two 2.1110 oximate ligands, while a chelating 1.0110 (py)₂CNO⁻ ion completes distorted trigonal bipyramidal coordination at each metal centre. The dimers are stabilized by intramolecular stacking interactions between the terminal (py)₂CNO⁻ ligands, and the structural effects of these interactions are discussed.