Polyphenol oxidase activity and implications on the quality of intermediate moisture and dried apples

This study aimed at investigating the water activity threshold for the polyphenol oxidase activity in Golden Delicious apple. Freeze-dried powders obtained from blanched and unblanched apples were equilibrated and stored at four water activity levels, ranging from 0.11 to 0.56, at 20 and 40 \ub0C, to differentiate between nonenzymatic and enzymatic browning. The contents of hydroxycinnamic acids, phloridzin, catechin, epicatechin, polymeric flavan 3-ols, and 5-hydroxymethylfurfural, the antioxidant activity values, and the Hunter colorimetric parameters of apple products were analyzed. Results showed that no polyphenol oxidase activity occurred in unblanched dehydrated apples stored at water activity levels between 0.11 and 0.32. In this water activity range, blanching pre-treatment accelerated the Maillard reaction in the products stored at 40 \ub0C, as observed from both higher 5-hydroxymethylfurfural formation and more intense red color development in blanched apples with respect to the unblanched ones. At the water activity level of 0.56, both increased redness and higher antioxidant degradation were observed in the unblanched apples with respect to the blanched apples, indicating that the threshold water activity for polyphenol oxidase was in the range 0.32\u20130.56. Among apple antioxidants, epicatechin was mostly affected by polyphenol oxidase activity, either by direct oxidation or by a coupled oxidation mechanism. Therefore, \u2018\u2018mild\u2019\u2019 pre-heating treatments or no pre-treatments could be proposed when the apple is to be stored and used at water activity below 0.32, whereas blanching should be applied for intermediate moisture apples or in food applications where moisture transfer from other ingredients could bring apples above this critical water activity level

Stochastic Inverse Modeling and Parametric Uncertainty of Sediment Deposition Processes Across Geologic Time Scales

In this work an integrated methodological and operational framework for diagnosis and calibration of Stratigraphic Forward Models (SFMs) which are typically employed for the characterization of sedimentary basins is presented. Model diagnosis rests on local and global sensitivity analysis tools and leads to quantification of the relative importance of uncertain model parameters on modeling goals of interest. Model calibration is performed in a stochastic framework, leading to estimates of distributions of model parameters (and ensuing spatial distributions of model outputs) conditional on available information. Starting from a considerable number of uncertain model parameters, which is typically associated with SFMs of the kind analyzed, the approach leads to the identification of a reduced set of parameters which are most influential to drive stratigraphic modeling results. Probability distributions of these model parameters conditional on available data are then evaluated through stochastic inverse modeling. To alleviate computational efforts, this step is performed through a combination of a surrogate model constructed through the Polynomial Chaos Expansion approach and a machine learning algorithm for efficient search of the parameter space during model inversion. As a test bed for the workflow, focus is on a realistic synthetic three-dimensional scenario which is modeled through a widely used SFM that enables one to perform three-dimensional numerical simulations of the accumulation of siliciclastic and carbonate sediments across geologic time scales. These results constitute a robust basis upon which further deployment of the approach to industrial field settings can be designed

Surgical leg rotation : cortical neuroplasticity assessed through brain mapping using transcranial magnetic stimulation

Rotationplasty (Borggreve-Van Nes operation) is a rare limb salvage procedure, most often applied to children presenting with sarcoma of the distal femur. In type A1 operation, the distal thigh is removed and the proximal tibia is axially rotated by 180\ub0, remodeled, grafted onto the femoral stump, and then prosthetized. The neurovascular bundle is spared. The rotated ankle then works as a knee. The foot plantar and dorsal flexors act as knee extensors and flexors, respectively. Functional results may be excellent. Cortical neuroplasticity was studied in three men (30-31 years) who were operated on the left lower limb at ages between 7 and 11 years and were fully autonomous with a custom-made prosthesis, as well as in three age-sex matched controls. The scalp stimulation coordinates, matching the patients' brain MRI spots, were digitized through a 'neuronavigation' optoelectronic system, in order to guide the transcranial magnetic stimulation coil, thus ensuring spatial precision during the procedure. Through transcranial magnetic stimulation driven by neuronavigation, the cortical representations of the contralateral soleus and vastus medialis muscles were studied in terms of amplitude of motor evoked potentials (MEPs) and centering and width of the cortical areas from which the potentials could be evoked. Map centering on either hemisphere did not differ substantially across muscles and participants. In the operated patients, MEP amplitudes, the area from which MEPs could be evoked, and their product (volume) were larger for the muscles of the unaffected side compared with both the rotated soleus muscle (average effect size 0.75) and the muscles of healthy controls (average effect size 0.89). In controls, right-left differences showed an effect size of 0.38. In no case did the comparisons reach statistical significance (P>0.25). Nevertheless, the results seem consistent with cortical plasticity reflecting strengthening of the unaffected leg and a combination of cross-education and skill training of the rotated leg.This is an open access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0, where it is permissible to download, share and reproduce the work in any medium, provided it is properly cited. The work cannot be changed in any way or used commercially. http://creativecommons.org/licenses/by-nc-nd/3.0

Mirror movements after stroke suggest facilitation from non primary motor cortex: a case report

When stroke occurs in adulthood, mirror movements (MMs: involuntary movements occurring in one hand when performing unilateral movements with the contralateral hand) in the paretic hand rarely occur. We present a case of an apparently healthy 54-year-old male presenting MMs in his left (non-dominant) hand. Further evaluation revealed diminished strength and dexterity in left hand, increased spinal excitability, decreased corticospinal excitability, occurrence of ipsilateral motor responses, enlarged cortical motor representation and imaging findings consistent with a previously undiagnosed right-subcortical stroke. MMs and ipsilateral motor responses may reflect the increased spinal motor neurons' excitability sustained by the spared non-primary ipsilesional motor areas

Superior mesenteric artery blood flow in systemic sclerosis patients

OBJECTIVE: Intestinal involvement is frequently observed in systemic sclerosis (SSc) and is associated with malnutrition and a decreased survival rate. Vascular lesions are claimed to underlie and precede these changes. The aim of this study was to establish whether a reduced mesenteric blood flow was present in SSc patients with no signs or symptoms of small bowel involvement. METHODS: Superior mesenteric artery (SMA) blood flow in the fasting state was measured by colour Doppler ultrasonography in 27 SSc patients and in 25 controls. The effect of a balanced liquid meal on mesenteric blood flow was measured in six matched patients and controls. RESULTS: In fasting SSc patients, there were reductions in mean SMA diameter (P<0.001), blood flow (213+/-92 vs 398+/-125 ml/min in controls, P<0.0001) and pulsatility index (3.49+/-1.0 vs 4.13+/-0.97 in controls, P<0.07). In both groups, the meal increased basal flow values and the differences between controls and patients in the fasting state were not significant. CONCLUSIONS: In the absence of symptoms of small bowel involvement, reversible SMA vasoconstriction is demonstrable in the fasting state in SSc patients

Hot shale in an ice world : paleoceanographic evolution of the northern Godwana margin during the Early paleozoic (Tanezzuft Formation, Tunisia)

The Tanezzuft Formation deposited in marine periglacial conditions on the northern Gondwana margin during the end of the "ice-house" climate that characterized the lowermost Silurian. The basal part of this sedimentary sequence is characterized by organic-rich facies with locally very high measured Total Organic Carbon (TOC) content up to values greater than 20%. While deposition of organic-rich sediments during greenhouse time interval is well known, deposition of black shales during ice-house conditions is poorly documented. The extraordinary paleoceanographic conditions that led to the accumulation and preservation of enormous amounts of organic matter in periglacial settings, makes this formation an atypical example of black shales deposition.The study area is situated on the North African Platform in southern Tunisia, on the northern flank of the Ghadames Basin. Petrophysical logs, biostratigraphic, organic- and inorganic-geochemical data from nine wells, are here integrated with the aim of reconstructing the depositional history of the Tanezzuft Formation and the role played by organic matter production, preservation and dilution through time. Data indicate that dilution - that is, depositional style and framework - had an important control on lateral and vertical distribution of the C organic-rich facies. TOC and Hydrogen Index (HI) maxima are found in correspondence of the main transgressive phases, with repetitive stacking patterns strongly associated with source rock properties. Organic matter production, as observed by detailed palynofacies analysis, was mainly marine in nature, with important contribution by Amorphous Organic Matter, Leiosphaeridia/Tasmanaceae and minor amounts of graptolites fragments. Geochemical data indicate that the organic-richest interval ("Hot Shale") of the Tanezzuft Formation deposited under severe anoxic conditions that resulted in enhanced organic matter preservation at the sea-floor. OF-Mod 3D, an organic facies modelling software tool (by SINTEF), is used in order to reconstruct and quantify the peculiar processes that controlled the exceptional accumulation of organic matter at the time of deposition. Modelling results indicate that water stratification was the most plausible process that drove organic-matter sedimentation under mesotrophic conditions. Density stratification was probably controlled by the deglaciation phase after the Hirnantian glaciation and/or by the flooded complex basin physiography that induced an inefficient circulation of the water masses. The complete recovery from these extreme paleoceanographic conditions implied progressive processes that took several hundred thousand years

Modelling parametric uncertainty in large-scale stratigraphic simulations

Abstract We combine forward stratigraphic models with a suite of uncertainty quantification and stochastic model calibration algorithms for the characterization of sedimentary successions in large scale systems. The analysis focuses on the information value provided by a probabilistic approach in the modelling of large-scale sedimentary basins. Stratigraphic forward models (SFMs) require a large number of input parameters usually affected by uncertainty. Thus, model calibration requires considerable time both in terms of human and computational resources, an issue currently limiting the applications of SFMs. Our work tackles this issue through the combination of sensitivity analysis, model reduction techniques and machine learning-based optimization algorithms. We first employ a two-step parameter screening procedure to identify relevant parameters and their assumed probability distributions. After selecting a restricted set of important parameters these are calibrated against available information, i.e., the depth of interpreted stratigraphic surfaces. Because of the large costs associated with SFM simulations, probability distributions of model parameters and outputs are obtained through a data driven reduced complexity model. Our study demonstrates the numerical approaches by considering a portion of the Porcupine Basin, Ireland. Results of the analysis are postprocessed to assess (i) the uncertainty and practical identifiability of model parameters given a set of observations, (ii) spatial distribution of lithologies. We analyse here the occurrences of sand bodies pinching against the continental slope, these systems likely resulting from gravity driven processes in deep sea environment