Authenticity green coffee bean species and geographical origin using near-infrared spectroscopy combined with chemometrics

To prevent the adulteration of agricultural resources and provide a solution to enhance the green coffee bean supply chain, authentication using the near-infrared spectroscopy (NIRS) technique was investigated. Partial least square with discrimination analysis (PLS-DA) models combined with various preprocessing methods were built from NIR spectra of 153 Vietnamese green coffee samples. The model combined with the standard normal variate and the first order of derivative yielded excellent performance in predicting coffee species with the error cross-validation of 0.0261. PLS-DA model of mean centre and first-order derivative spectra also yielded good performance in verifying geographical indication of green coffee with the error of 0.0656. By contrast, the predicting abilities of post-harvest methods were poor. The overall results showed a high potential of the NIRS in online authentication practices.     

Coexistence of three ferroelectric phases and enhanced piezoelectric properties in BaTiO3–CaHfO3 lead-free ceramics

Perovskite ferroelectrics possess the fascinating piezoelectric properties near a morphotropic phase boundary, attributing to a low energy barrier that the results in structural instability and easy polarization rotation. In this work, a new lead-free system of (1-x)BaTiO₃-xCaHfO₃ was designed, and characterized by a coexistence of ferroelectric rhombohedral-orthorhombic-tetragonal (R-O-T) phases. With the increase amount of CaHfO₃ (x), a stable coexistence region of three ferroelectric phases (R-O-T) exists at 0.06 ≤ x ≤ 0.08. Both large piezoelectric coefficient (d₃₃～400 pC/N), inverse piezoelectric coefficient (d₃₃^*～547 pm/V) and planar electromechanical coupling factor (k_p～58.2%) can be achieved for the composition with x = 0.08 near the coexistence of three ferroelectric phases. Our results show that the materials with the composition located at a region where the three ferroelectric R-O-T phases coexist would have the lowest energy barrier and thus greatly promote the polarization rotation, resulting in a strong piezoelectric response.     

Research on the overall architecture of Internet of Things middleware for intelligent industrial parks

With the continuous development of the Internet of Things technology and the proposal of “Made in China 2025”, the construction of IoT applicat     

The extended quadratic residue code is the only (48,24,12) self-dual doubly-even code

An extremal self-dual doubly-even binary (n,k,d) code has a minimum weight d=4/spl lfloor/n/24/spl rfloor/+4. Of such codes with length divisible by 24, the Golay code is the only (24,12,8) code, the extended quadratic residue code is the only known (48,24,12) code, and there is no known (72,36,16) code. One may partition the search for a (48,24,12) self-dual doubly-even code into three cases. A previous search assuming one of the cases found only the extended quadratic residue code. We examine the remaining two cases. Separate searches assuming each of the remaining cases found no codes and thus the extended quadratic residue code is the only doubly-even self-dual (48,24,12) code.     

Mining constrained gradients in large databases

Many data analysis tasks can be viewed as search or mining in a multidimensional space (MDS). In such MDSs, dimensions capture potentially important factors for given applications, and cells represent combinations of values for the factors. To systematically analyze data in MDS, an interesting notion, called "cubegrade" was recently introduced by Imielinski et al. [2002], which focuses on the notable changes in measures in MDS by comparing a cell (which we refer to as probe cell) with its gradient cells, namely, its ancestors, descendants, and siblings. We call such queries gradient analysis queries (GQs). Since an MDS can contain billions of cells, it is important to answer GQs efficiently. We focus on developing efficient methods for mining GQs constrained by certain (weakly) antimonotone constraints. Instead of conducting an independent gradient-cell search once per probe cell, which is inefficient due to much repeated work, we propose an efficient algorithm, LiveSet-Driven. This algorithm finds all good gradient-probe cell pairs in one search pass. It utilizes measure-value analysis and dimension-match analysis in a set-oriented manner, to achieve bidirectional pruning between the sets of hopeful probe cells and of hopeful gradient cells. Moreover, it adopts a hypertree structure and an H-cubing method to compress data and to maximize sharing of computation. Our performance study shows that this algorithm is efficient and scalable. In addition to data cubes, we extend our study to another important scenario: mining constrained gradients in transactional databases where each item is associated with some measures such as price. Such transactional databases can be viewed as sparse MDSs where items represent dimensions, although they have significantly different characteristics than data cubes. We outline efficient mining methods for this problem.     

Modelling biological gel contraction by cells: mechanocellular formulation and cell traction force quantification

Traction forces developed by most cell types play a significant role in the spatial organisation of biological tissues. However, due to the complexity of cell-extracellular matrix interactions, these forces are quantitatively difficult to estimate without explicitly considering cell properties and extracellular mechanical matrix responses. Recent experimental devices elaborated for measuring cell traction on extracellular matrix use cell deposits on a piece of gel placed between one fixed and one moving holder. We formulate here a mathematical model describing the dynamic behaviour of the cell-gel medium in such devices. This model is based on a mechanical force balance quantification of the gel visco-elastic response to the traction forces exerted by the diffusing cells. Thus, we theoretically analyzed and simulated the displacement of the free moving boundary of the system under various conditions for cells and gel concentrations. This model is then used as the theoretical basis of an experimental device where endothelial cells are seeded on a rectangular biogel of fibrin cast between two floating holders, one fixed and the other linked to a force sensor. From a comparison of displacement of the gel moving boundary simulated by the model and the experimental data recorded from the moving holder displacement, the magnitude of the traction forces exerted by the endothelial cell on the fibrin gel was estimated for different experimental situations. Different analytical expressions for the cell traction term are proposed and the corresponding force quantifications are compared to the traction force measurements reported for various kind of cells with the use of similar or different experimental devices.     

Effects of Al3+ and Be2+ ions combined with NaF on ciliary process adenylyl cyclase activity and aqueous humor dynamics in the rabbit eye

PURPOSE: The activity of Al3+, Ga3+, and Be2+ ions in the presence of NaF to directly activate G-proteins was investigated by their potentiative effect on forskolin (FSK)-activated adenylyl cyclase in rabbit ciliary process membranes and their effects on aqueous humor dynamics in vivo. METHODS: Adenylyl cyclase (AC) was determined by radiometric conversion of ATP to cAMP by the particulate fraction of rabbit ciliary processes. Intravitreal injections of sterile solutions of analytical grade salts were made into the center of the vitreous in a volume of 20 microliters. Intraocular pressure, aqueous humor flow, and uveoscleral outflow measurements were made by pneumatonometry, fluorophotometry, and fluorescein-dextran method, respectively. Outflow facility was determined by tonography in the intact eyes and by two-level constant pressure perfusion in cannulated eyes. RESULTS: Both Al3+ (EC50, 40 mumol/l) and Be2+ (EC50, 11 mumol/l) in the presence of 0.5-2 mM NaF activated the stimulatory G-protein Gs. Ga3+ was ineffective and did not antagonize the activation by Al3+. Intravitreal injections of Al3+ (1 mumol/eye) or Be2+ (0.5 or 1 mumol/eye) had no significant intraocular pressure (IOP) effect, nor did 1.5 or 3 mumol/eye of NaF, but when either cation was injected together with NaF, IOP decreased by up to 40% for up to 140 hr. At the time of maximum IOP effect (72 hr) aqueous humor flow determined by fluorophotometry was decreased in BeCl2+ NaF-treated eyes by 40% relative to BeCl2-treated eyes; however, tonographic facility of outflow was unaffected. Uveoscleral flow was also decreased by 38% in BeCl2+ NaF treated eyes. CONCLUSIONS: These findings support the hypothesis that Gs activation of ciliary process adenylyl cyclase decreases aqueous humor formation rate in rabbit eyes, and that activation of G-proteins mediates contraction of ciliary muscles causing a decrease of aqueous humor outflow via the uveoscleral route. The results suggest that G-proteins putatively involved in trabecular facility changes are less sensitive to activation by BeF3- than are other parameters of aqueous humor dynamics.