Bauhinia forficata Link authenticity using flavonoids profile: Relation with their biological properties

HPLC-DAD-ESI/MSⁿ was used to ascertain the authenticity of two certified and two commercial Bauhinia forficata Link samples. Different flavonoids profiles were obtained, involving 39 compounds. Just kaempferol-3-O-(2-rhamnosyl)rutinoside was found in all analysed samples. Five compounds were common to the certified samples of B. forficata Link and B. forficata Link subsp. pruinosa (Vogel) Fortunato & Wunderlin, being kaempferol derivatives the most representative ones. The phenolic composition of B. forficata Link subsp. pruinosa (Vogel) Fortunato & Wunderlin is described herein for the first time, accounting for eight compounds, while 10 new compounds were identified in B. forficata Link. Commercial B. forficata Link showed higher contents of quercetin derivatives, in addition to the presence of myricetin derivatives and flavonoids-(galloyl)glycosides, for which the MS fragmentation pattern is reported for the first time. B. forficata Link and the two commercial samples were able to inhibit α-glucosidase, with EC₅₀ values lower than that found for acarbose. Mild effects on cholinesterases were observed with the certified samples, while commercial ones were more effective. The same behaviour was observed concerning the scavenging of DPPH, nitric oxide and superoxide radicals. The presence of high contents of quercetin derivatives in commercial samples seems to directly influence their biological properties. The differences between phenolic profiles and their relation with the authenticity of commercial samples are discussed.     

Browning Inhibition in Fresh-cut'Fuji'Apple Slices by Natural Antibrowning Agents

ABSTRACT Response surface methodology was used to study the effect of antibrowning agents (4‐hexylresorci‐nol, glutathione, N‐acetylcysteine, and ascorbic acid) and storage time (14 d) on the color of minimally processed Fuji apples. The selected color parameters were L*,a*, b*, hue angle (h*), and color difference (ΔE*). Storage time had a significant effect on all the studied color parameters (P± 0.05). 4‐hexylresorcinol showed the most effective individual effect on keeping constant a*values (P± 0.0001). Besides, the interaction of N‐acetylcysteine/ glutathione was found to have a significant effect (P± 0.05) on maintaining a* values over time. On the other hand, individual treatment with N‐acetylcysteine in concentrations higher than 0.75% w/v may be used to preserve a*and h*.According to the F‐test, 4‐hexylresorcinol and N‐acetylcysteine (P± 0.05) displayed a significant individual effect on ΔE*, indicating that ΔE* decreased when increasing the concentration of these antibrowning agents. Nevertheless, color difference went down when 4‐hexylresorcinol concentration increased up to 0.5%, but higher concentrations of this agent led to an increase in ΔE* that indicates browning.     

General model to build awnings and external walls with optimum shading interaction

A general model is proposed to optimize the shading interaction between an awning and an external wall that project shadows on the facade of a construction. The original method was presented by the authors in Renewable Energy 28 (2003): 111, for a particular shading proposal. They emphasize the advantage of a one-dimensional approach to solve the problem of this interaction, analyzing the shadows projected by these elements from a side view. The generalized method, presented in this paper, is useful for architects to design shelter projects with more alternatives in the use of such shading devices. The general model also permits study and evaluation of any strategy chosen by the builder to shadow a facade, with an emphasis on windowpane shading, through graphical outputs of the solar performance.     

Uncalibrated visual servoing using the fundamental matrix

This paper describes a new algorithm for visual control of an uncalibrated 3 DOF joint system, using two weakly calibrated fixed cameras. The algorithm estimates on-line the Image Jacobian, a matrix which linearly relates joint velocity and image feature velocity. In our experiments we prove that by using the fundamental matrix, robustness of the estimation in the presence of noise is significantly increased with respect to already existing algorithms in specialized literature.     

Optimal and heuristic solution methods for a multiprocessor machine scheduling problem

This paper deals with the scheduling of operations on a multiprocessor machine in the context of shoe manufacturing. Multiprocessor machines are composed of several parallel processors. Unlike parallel machines, the entire machine needs to be stopped whenever a single processor needs a setup. Our industrial partner, one of the major winter-shoe manufacturers in Canada, offers a relatively large variety of models. For each of these models, all the sizes proposed by this manufacturer must be produced in various quantities. Our objective is to schedule the production of the required sizes on the machine's different processors in order to minimize the global makespan, which includes both the production time and the set up time. We first present a mathematical formulation of the problem. Then, we introduce a decomposition procedure based on the mathematical model, and we demonstrate that this procedure is very efficient for small- and medium-size instances. We also propose two construction heuristics and two improvement heuristics for larger problems, and we report the results of our extensive computational experiments to demonstrate the quality of the proposed heuristics in terms of reducing production time and computational effort.     

A search space reduction methodology for data mining in large databases

Given the present need for Customer Relationship and the increased growth of the size of databases, many new approaches to large database clustering and processing have been attempted. In this work, we propose a methodology based on the idea that statistically proven search space reduction is possible in practice. Two clustering models are generated: one corresponding to the full data set and another pertaining to the sampled data set. The resulting empirical distributions were mathematically tested to verify a tight non-linear significant approximation.     

Control of a Robotic Wheelchair Using Recurrent Networks

This paper describes an adaptive neural control system for governing the movements of a robotic wheelchair. It presents a new model of recurrent neural network based on a RBF architecture and combining in its architecture local recurrence and synaptic connections with FIR filters. This model is used in two different control architectures to command the movements of a robotic wheelchair. The training equations and the stability conditions of the control system are obtained. Practical tests show that the results achieved using the proposed method are better than those obtained using PID controllers or other recurrent neural networks models     

Circadian rhythm of fatty acid desaturation in mouse liver

A study was made of the diurnal changes in liver microsomal desaturation of labeled stearic, linoleic and α-linolenic acids to oleic, γ-linolenic and octadeca-6,9,12,15-tetraenoic acids, respectively. C3H-S mice were used and were exposed to light-dark cycles. A circadian rhythm was observed for stearic acid desaturation, and a different one for linoleic acid. Linoleic and α-linolenic desaturation had similar responses in the day cycle. This would indicate that different mechanisms control the oxidative desaturations of the fatty acids in the 9 and 6 carbons. The fatty acid composition of the whole liver and liver microsomes also showed variations. Remarkable oscillations were observed for stearic and oleic acids. Neither the total protein synthesis nor the free fatty acid concentration in the microsomes followed a rhythm parallel to the desaturation of the studied fatty acids. The injection of cycloheximide 4 hr before measuring the desaturation modified the circadian variation of both the 9 and 6 desaturations. The modification induced by cycloheximide was considered to indicate that both variations are related to the synthesis of specific proteins but not to that of a degradative or inhibitory protein.     

Nutritional and antioxidant status of an institutionalized elderly group in Murcia (Spain)

The aging of the population is giving rise to a large number of studies aimed at improving the quality of life, considering diet as a major contributing factor in this life stage. The objectives of the present study were to evaluate the nutritional status of a group of institutionalized elderly in Murcia, Spain, and to relate the diet to anthropometric and biochemical indices, paying special attention to total antioxidant status. The dietary evaluation showed excessive intakes of proteins and lipids, and deficiencies in those of carbohydrates, dietary fiber, zinc, iodine and vitamins A, E and D. The high proportion of overweight observed were not significantly correlated to the energy intakes. Although total plasma antioxidant status was low (0.62 mM eq Trolox and 0.98 mM eq Fe(II)) compared with reference values, estimated oxidative risk in this group of elderly was low according to plasma levels of vitamins C, A & E.