Search results for "Biological system"
showing 10 items of 319 documents
Equi-intensity across the SpectrumTM taste scales
2015
Abstract This work aimed to study the equi-intensity across the Spectrum™ taste scales. The approach consisted of a comparison of four reference points illustrating the same level of intensity across the scales using two very different methods: 2-alternative forced-choice (2-AFC) and Labeled Magnitude Scale (LMS). The comparisons across these scales were based on caffeine, citric acid, sodium chloride, sucrose, and monosodium glutamate in water solutions, at different concentrations, prepared according to the guidelines given for the Spectrum™ method. A scale concerning the umami taste, designed in the spirit of the Spectrum™ scales, was also studied in this work. Both procedures produced s…
Cluster classification of dysphagia-oriented products considering flow, thixotropy and oscillatory testing
2011
Abstract The present paper proposes an objective classification of commercial thickened food widely used in patients with dysphagia. A total of 34 commercial enteral nutrition products were analyzed (beverages, main courses and desserts) corresponding to 6 different commercial brands. All these products contain different hydrocolloids (i.e., starch, xanthan gum, carrageenans, etc.) as thickeners, in order to get the desired texture. Joint consideration has been made of viscous behavior (flow and thixotropy) and viscoelastic behavior (oscillatory testing). Rheological measurements were fitted to different rheological and empirical mathematical models, and a total of 11 parameters were genera…
A rapid method for the differentiation of yeast cells grown under carbon and nitrogen-limited conditions by means of partial least squares discrimina…
2012
This paper shows the ease of application and usefulness of mid-IR measurements for the investigation of orthogonal cell states on the example of the analysis of Pichia pastoris cells. A rapid method for the discrimination of entire yeast cells grown under carbon and nitrogen-limited conditions based on the direct acquisition of mid-IR spectra and partial least squares discriminant analysis (PLS-DA) is described. The obtained PLS-DA model was extensively validated employing two different validation strategies: (i) statistical validation employing a method based on permutation testing and (ii) external validation splitting the available data into two independent sub-sets. The Variable Importa…
Robust dynamical pattern formation from a multifunctional minimal genetic circuit.
2010
Abstract Background A practical problem during the analysis of natural networks is their complexity, thus the use of synthetic circuits would allow to unveil the natural mechanisms of operation. Autocatalytic gene regulatory networks play an important role in shaping the development of multicellular organisms, whereas oscillatory circuits are used to control gene expression under variable environments such as the light-dark cycle. Results We propose a new mechanism to generate developmental patterns and oscillations using a minimal number of genes. For this, we design a synthetic gene circuit with an antagonistic self-regulation to study the spatio-temporal control of protein expression. He…
Biologically inspired information processing and synchronization in ensembles of non-identical threshold-potential nanostructures.
2013
Nanotechnology produces basic structures that show a significant variability in their individual physical properties. This experimental fact may constitute a serious limitation for most applications requiring nominally identical building blocks. On the other hand, biological diversity is found in most natural systems. We show that reliable information processing can be achieved with heterogeneous groups of non-identical nanostructures by using some conceptual schemes characteristic of biological networks (diversity, frequency-based signal processing, rate and rank order coding, and synchronization). To this end, we simulate the integrated response of an ensemble of single-electron transisto…
The Respiratory Potential of Oxygen: A New Quantity to Characterize State, Effects and Bio-Availability of the Gas in Organism
1992
A number of quantities are known which enable to characterize the state of oxygen in blood, for instance: the concentration, which means the physically solved mass per volume; or the content, which comprises the whole mass per volume irrespective of the molecular state; or capacity, which is the chemically bound mass of oxygen per volume and, relatively, the saturation, or the oxygen partial pressure. These various quantities may be divided into two types: the mass-related and the not-mass-related ones.
Ovine Carotid Artery-Derived Cells as an Optimized Supportive Cell Layer in 2-D Capillary Network Assays
2014
PLoS one 9(3), e91664 (2014). doi:10.1371/journal.pone.0091664
QSPR with descriptors based on averages of vertex invariants. An artificial neural network study
2014
New type of indices, the mean molecular connectivity indices (MMCI), based on nine different concepts of mean are proposed to model, together with molecular connectivity indices (MCI), experimental parameters and random variables, eleven properties of organic solvents. Two model methodologies are used to test the different descriptors: the multilinear least-squares (MLS) methodology and the Artificial Neural Network (ANN) methodology. The top three quantitative structure–property relationships (QSPR) for each property are chosen with the MLS method. The indices of these three QSPRs were used to train the ANNs that selected the best training sets of indices to estimate the evaluation sets of…
QSPR/QSAR Studies of 2-Furylethylenes Using Bond-Level Quadratic Indices and Comparison with Other Computational Approaches
2017
The recently introduced, non-stochastic and stochastic quadratic indices (Marrero-Ponce <em>et al. J. Comp. Aided Mol. Des.</em> 2006, 20, 685-701) were applied to QSAR/QSPR studies of heteroatomic molecules. These novel bond-based molecular descriptors (MDs) were used for the prediction of the partition coefficient (log P), and the antibacterial activity of 34 derivatives of 2-furylethylenes. Two statistically significant QSPR models using non-stochastic and stochastic bond-based quadratic indices were obtained (R<sup>2</sup> = 0.971, s = 0.137 and R<sup>2</sup> = 0.986, s = 0.096). These models showed good stability to data variation in leave-one-out (L…
One-sensor electronic olfactometer for rapid sorting of fresh fruit juices
2001
Abstract A low-cost electronic olfactometer was developed, based on virtual sensors array (an array of signals from a single metal oxide sensor) and on our proprietary semi-automated sampling system. This concept enables us to drastically improve the sensitivity and selectivity of the entire olfactometer to make it suited to food products analysis. Each step of the prototype was checked separately in earlier work, and finally the system performance was evaluated first on pure chemicals, and then at-line for grape juice during grape-harvesting in Champagne. It is shown that over a 3-week vintage period, the drift of the unique-sensor was quite low (absolute baseline value: avg., 2152; std., …