Heuristic and exact algorithms for a min–max selective vehicle routing problem

In this work, we investigate a vehicle routing problem where not all clients need to be visited and the goal is to minimize the longest vehicle route. We propose two exact solution approaches for solving the problem: a Branch-and-cut (BC) algorithm and a Local Branching (LB) method that uses BC as its inner solver. Our computational experience indicates that, in practice, the problem is difficult to solve, mainly when the number of vehicles grows. In addition to the exact methods, we present a heuristic that relies on GRASP and on the resolution of a restricted integer program based on a set covering reformulation for the problem. The heuristic was capable of significantly improving the best solutions provided by BC and LB, in one tenth of the times taken by them to achieve their best upper bounds.     

In-mouth mechanisms leading to flavor release and perception

During eating, foods are submitted to two main oral processes-chewing, including biting and crushing with teeth, and progressive impregnation by saliva resulting in the formation of a cohesive bolus and swallowing of the bolus. Texture influences the chewing behavior, including mastication and salivation, and in turn, these parameters influence texture perception and bolus formation. During this complex mouth process, flavor compounds are progressively released from the food matrix. This phenomenon is mainly dependent on the food texture, the composition and in-mouth breakdown, and on saliva impregnation and activity, but an individual's anatomical and physiological aspects characteristics should also be taken into account. This article reviews the knowledge and progresses on in-mouth processes leading to food breakdown and flavor release and affecting perception. Relationships between food texture and composition, food breakdown, oral physiology, and flavor release are developed and discussed. This review includes not only the mechanical aspects of oral physiology but also the biological aspects such as the influence of saliva composition, activity, and regulation on flavor perception. In vitro and in silico approaches are also described.     

Mortality risk in hemodialysis patients according to anemia control and erythropoietin dosing

There is no consensus about the toxicity of erythropoiesis‐stimulating agents among hemodialysis patients. We aimed to calculate the risk of death according to anemia control and erythropoietin (EPO) dosing among end‐stage renal disease patients undergoing hemodialysis. We retrospectively studied 156 end‐stage renal disease patients on hemodialysis from a single renal unit during 12 months. Participants were classified according to anemia control into four groups: excellent (A), good (B), moderate (C) and bad (D) control. They were also classified according to EPO dosing into two groups: usual and high EPO dosing. The Cox proportional hazards regression model, adjusted for the difference in age, sex, time on dialysis, comorbidity, albumin, and Kt/V index, was performed to calculate the risk of death according to anemia control and EPO dosing profiles. Multivariate analysis by backward stepwise logistic regression was used to calculate the risk of death according to the variables that differed in the comparison between survivors and nonsurvivors. The hazard ratio of death was not significant according to anemia control profile C/D vs. A/B, but hazard ratio was 2.967 (95% confidence interval [CI] = 1.132–7.777; P = 0.027) for high EPO dosing profile patients. The multivariate analysis showed comorbidity (odds ratio [OR] = 8.958; 95% CI = 2.843–26.223; P < 0.001], high EPO dosing profile (OR = 5.172; 95% CI = 1.663–16,081; P = 0.005), age (OR = 1.056; 95% CI = 1.020–1.094; P = 0.002), and mean hemoglobin (OR = 0.435; 95% CI = 0.267–0.709; P = 0.001) to be predictive of death. Even though we cannot conclude that mortality risk is due to EPO toxicity, hemodialysis patients using high EPO dosing must be seen as at risk.     

Partial discharge signal denoising with spatially adaptive wavelet thresholding and support vector machines

In this paper an improved method to denoise partial discharge (PD) signals is presented. The method is based on the wavelet transform (WT) and support vector machines (SVM) and is distinct from other WT-based denoising strategies in the sense that it exploits the high spatial correlations presented by PD wavelet decompositions as a way to identify and select the relevant coefficients. PD spatial correlations are characterized by WT modulus maxima propagation along decomposition levels (scales), which are a strong indicative of the their time-of-occurrence. Denoising is performed by identification and separation of PD-related maxima lines by an SVM pattern classifier. The results obtained confirm that this method has superior denoising capabilities when compared to other WT-based methods found in the literature for the processing of Gaussian and discrete spectral interferences. Moreover, its greatest advantages become clear when the interference has a pulsating or localized shape, situation in which traditional methods usually fail.     

Relevance of omission tests to determine flavour-active compounds in food: application to cheese taste

One of the main problems to overcome in determining the flavour-active compounds of a food product is to point out a causative linkage which may exist between its composition obtained by physico-chemical analysis, and its flavour properties determined by a trained sensory panel. Starting with an overview of the strategies classically used to solve the problem and their limitations, this paper presents an alternative methodology based on omission tests. Through different applications concerning cheese taste studies, the main interests of this methodology are shown and discussed.     

Contents of Carotenoids, Tocopherols and Sterols in Acacia cyanophylla Seed Oils

Seeds from 12 Acacia cyanophylla ecotypes, harvested in Tunisia, were examined for their seed oil contents of carotenoids, tocopherols and phytosterols. The average carotenoid content (lutein and zeaxanthin) was ca. 102 mg kg^?1 of total extracted lipids. Lutein (ca. 97 mg kg^?1 of total extracted lipids) was usually more abundant than zeaxanthin (ca. 5 mg kg^?1 of total extracted lipids). The mean total tocopherol content was ca. 704 mg kg^?1 of total extracted lipids. The main isomer was α‐tocopherol, with more than 75 % of total tocopherols (ca. 528 mg kg^?1 of total extracted lipids), followed by γ‐tocopherol (ca. 168 mg kg^?1 of total extracted lipids) and δ‐tocopherol (ca. 86 mg kg^?1 of total lipids). High levels of phytosterols (ca. 7.8 g kg^?1 of total extracted lipids) were detected, among which β‐sitosterol was the most abundant (47 %). All these results highlight the richness of carotenoids, tocopherols and sterols in A. cyanophylla seed oil, and imply that this species might constitute a potential resource for the development of functional foods.     

Overexpression of DNA polymerase beta in cell results in a mutator phenotype and a decreased sensitivity to anticancer drugs

DNA polymerase beta (pol beta) is the most error prone of all known eukaryotic DNA polymerases tested in vitro. Here, we show that cells overexpressing pol beta cDNA have acquired a spontaneous mutator phenotype. By measuring the appearance of mutational events using three independent assays, we found that genetic instability increased in the cell lines that overexpressed pol beta. In addition, these cells displayed a decreased sensitivity to cancer chemotherapeutic, bifunctional, DNA-damaging agents such as cisplatin, melphalan, and mechlorethamine, resulting in enhanced mutagenesis compared with control cells. By using cell-free extracts and modified DNA substrates, we present data in support of error-prone translesion replication as one of the key determinants of tolerance phenotype. These results have implications for the potential role of pol beta overexpression in cancer predisposition and tumor progression during chemotherapy.