Surface treatments and coatings to maintain fresh‐cut mango quality in storage

BACKGROUND: Edible coatings may extend fresh‐cut fruit storage by preventing moisture loss and decreasing gas exchange. This study evaluated the effect of an antibrowning dip (calcium ascorbate, citric acid and N‐acetyl‐L ‐cysteine), followed or not with carboxymethylcellulose (CMC) or carrageenan coatings on quality of fresh‐cut mangoes stored at 5 °C for up to 20 days. A fourth treatment, only used in one of four experiments, consisted of chitosan. Treatments were applied on ‘Tommy Atkins’, ‘Kent’ and ‘Keitt’ mangoes harvested from Homestead (FL), and on imported store‐bought mangoes. RESULTS: The antibrowning dips maintained the best visual quality during storage for all cultivars, as indicated by higher b*, hue and L*. The CMC coating maintained similar visual quality, but carrageenan or chitosan decreased L* and b*. The antibrowning dip containing calcium ascorbate reduced firmness loss on cut pieces of ‘Keitt’, ‘Kent’ and store‐bought mangoes. The antibrowning treatment maintained higher titratable acidity for ‘Kent’ and ‘Keitt’, resulting in lower sensory sweetness. CONCLUSION: This study with repeated experiments showed that calcium ascorbate with citric acid and N‐acetyl‐L ‐cysteine maintained cut mango slices attractiveness in storage by keeping light color in both varieties. The addition of a polysaccharide coating did not consistently improve quality. Published in 2010 by John Wiley & Sons, Ltd.     

Parallel interference cancellation efficiency for noisy signals in O-CDMA system

The aim of this paper is to evaluate the robustness of Parallel Interference Cancellation (Pic) to noise contribution for an optical Code Division Multiple Access system. The theoretical expression of thePic error probability is developed in the case of white additive Gaussian noise. From theoretical analysis, we show that, even with noise contribution, thePic receiver outperforms the Conventional Correlation Receiver (Ccr). Moreover, the results highlight that, for a given performance, thePic receiver relaxes not only the constraint on the code length, but also the Signal to Noise Ratio compared toCcr. Particularly, this is proofed in access network context, i.e. 30 users withBer lt; 10^?9.     

Epicuticular Factors Involved in Host Recognition for the Aphid Parasitoid Aphidius rhopalosiphi

In insect parasitoids, fitness is dependent on the host finding and recognition abilities of the female. Host recognition cues have been described for various host–parasitoid systems, but are still under investigation in aphid parasitoids. Our study aimed to clarify the respective role of physical and chemical cues in recognition of the aphid cuticle. Shed aphid exuviae were used as an elicitor in order to avoid any influence of color, movement, or volatiles present in a living aphid. We assessed the effect of chemical and heat treatments on the texture of the cuticle by using scanning electron microscopy and tested the recognition of treated cuticles by the parasitoid. We showed that recognition cues of the cuticle can be removed chemically (using combined treatments with n-hexane and methanol). Moreover, heat treatment destroyed the physical texture of the cuticle without significantly reducing parasitoid recognition. In a second step, we showed that epicuticular extracts deposited on pieces of paper triggered female attack behavior. First results concerning the chemical composition of the active extract are presented. This study shows that chemical compounds extractable by organic solvents mediate cuticle recognition by aphid parasitoids.     

Embedding a Threshold Concept in Teaching and Learning of Product Development Management

This paper uses insights from the literature on threshold concepts to develop a structure for understanding teaching and learning in the area of managing product development. The paper defines the threshold concept, outlines pedagogic principles and describes learning activities that seek to enact these principles. The paper is based upon experience of an established final‐year university undergraduate course.     

Oxidation in fish oil-enriched mayonnaise: 4. Effect of tocopherol concentration on oxidative deterioration

The effect of the water-dispersible tocopherol preparation, Grindox 1032, and the oil-soluble tocopherol preparation, Toco 70, on oxidative stability in fish oil-enriched mayonnaise was examined. The two commercial antioxidant preparations were supplemented in different levels corresponding to 20-280 ppm tocopherol in addition to the 600 ppm present in the oils used for the mayonnaise. The oxidative stability was assessed by sensory analysis, the tendency of formation of free radicals, and concentrations of lipid hydroperoxides and volatile oxidation products. The effect of tocopherol on oxidation depended on the nature and the concentration of the tocopherol preparation employed, and it also depended on the parameters evaluated. Addition of high levels of Grindox 1032 (~140-280 ppm tocopherol) thus decreased the intensity of rancid off-flavor, but increased the formation of fishy off-flavors, the tendency of free radical formation and the concentration of certain volatiles. In contrast, low levels of Grindox 1032 (<70 ppm tocopherol) reduced the concentration of some volatiles, but did not seem to influence the off-flavor profile of the mayonnaise. Toco 70, which was only supplemented in low levels (<40 ppm tocopherol) increased the tendency for free radical formation, changed the profile of volatiles, and did not have a clear effect on the fishy and rancid off-flavor formation. Thus, additional tocopherol did not appear to be an efficient antioxidant in fish oil-enriched mayonnaise, perhaps because it cannot prevent the metal-catalyzed decomposition of peroxides, which we previously suggested to play an important role in mayonnaise.     

Passive geolocalization of radio transmitters: Algorithm and performance in narrowband context

Passive localization commonly consists of a two steps strategy. In the first step, intermediate parameters, often called measurements (such as angles of arrival (AOA), times of arrival (TOA), etc.) are measured on several base stations equipped with sensor arrays. In a second step, the transmitted intermediate parameters are then used to estimate the position at a central processing unit. Such approach is suboptimal. To overcome this limitation, one step algorithms were recently proposed. They exploit simultaneously all received signals of all base stations seen as a global array in order to provide the source positions directly. In this paper, we propose an original one step algorithm called global MUSIC approach (GMA). The GMA offers better performance in narrowband context. Moreover it does not require the use of filter banks in the wideband signal context, contrary to the recently proposed direct position determination (DPD). GMA appears to outperform the DPD in wideband context. We also investigate in this paper by means of a Cramer-Rao bound analysis the potential gain achievable by a one step approach compared to a conventional two steps approach. Finally, numerical results illustrate the improvement of the proposed method compared to existing techniques in terms of location error and robustness to the time-bandwidth product.     

An exploration of empowerment in manufacturing enterprises

This paper investigates empowerment within manufacturing production. Empowerment is multidimensional. Understanding the implications of operationalising empowerment requires an appreciation of all its dimensions. These dimensions are captured in Empowerment Profiles, which are incorporated within a conceptual framework. A sample of the Empowerment Profiles is validated using case studies. The Empowerment Profiles appear to have potential as a tool to assist in preparing to implement empowered work strategies, focusing attention on issues to be considered.