AODVCS,a new bio-inspired routing protocol based on cuckoo search algorithm for mobile ad hoc networks

Mobile ad hoc networks (MANETs) are becoming an emerging technology that offer several advantages to users in terms of cost and ease of use. A MANET is a collection of mobile nodes connected by wireless links that form a temporary network topology that operates without a base station and centralized administration. Routing is a method through which information is forwarded from a transmitter to a specific recipient. Routing is a strategy that guarantees, at any time, the connection between any two nodes in a network. In this work, we propose a novel routing protocol inspired by the cuckoo search method. Our routing protocol is implemented using Network simulator 2. We chose Random WayPoint model as our mobility model. To validate our work, we opted for the comparison with the routing protocol ad hoc on-demand distance vector, destination sequence distance vector and the bio-inspired routing protocol AntHocNet in terms of the quality of service parameters: packet delivery ratio and end-to-end delay (E2ED).     

Transmission Power Control Aware Routing in Cognitive Radio Ad Hoc Networks

Abstract—Cognitive radio technology has drawn much attention since it is a promising candidate to efficiently utilize the scarce radio resources. However, cognitive radio introduces new challenges in the protocol stacks in wireless networks. This paper proposes a routing protocol for Cognitive Radio Ad Hoc Networks (CRAHNs), called Transmission Power Control aware AODV (TPC-AODV). TPC-AODV is based on Ad hoc On Demand Distance Vector (AODV) routing protocol. The main objectives of TPC-AODV are to avoid interruption of primary users’ communication and to support basic Quality of Service for secondary users. TPC-AODV takes inputs from both secondary users’ application requirements and the channel condition after spectrum sensing. These inputs enable secondary users’ communication with specific transmission power on the selected channel. Our simulation results show that TPC-AODV improves network performance in terms of throughput and delay compared to AODV in CRAHNs.     

Insights into the role of quorum sensing in food spoilage

Food spoilage is a consequence of the degrading enzymatic activity of some food-associated bacteria. Several proteolytic, lipolytic, chitinolytic, and pectinolytic activities associated with the deterioration of goods are regulated by quorum sensing, suggesting a potential role of such cell-to-cell communication in food spoilage. Here we review quorum sensing signaling molecules and methods of their detection and quantification, and we provide insights into the role of quorum sensing in food spoilage and address potential quorum sensing inhibitors that might be used as biopreservatives.     

Inhibitory effect of acid concentration,aging, and different packaging on Escherichia coli O157:H7 and on color stability of beef

The presence of pathogens such as Escherichia coli O157:H7 (EC) represents risks to public health and to economy of Brazilian beef industry. In this context, the application of lactic acid (LA) is an efficient practice employed to reduce bacterial count without compromising consumer safety. Our aim was to verify the inhibitory effect of LA application combined with aging and different packaging on EC and its effects on beef color. The LA effect on EC counts was concentration dependent during aging and storage, with T2 (10% of LA added) demonstrating greater (p < .05) reductions than T1 (5% of LA added). Aging did not affect (p > .05) EC counts, however reduced (p < .05) the total aerobic mesophilic bacteria. LA application promoted a decrease on beef redness (p > .05) after application and during storage. LA treatment (T2) promoted a reduction in E. coli O157:H7, despite the effects on beef color.

Practical applications

The present data evidence a breakthrough in lactic acid (LA) researches once evaluate the inhibitory effect of aging, LA concentration and package on Escherichia coli O157:H7 and the influence of these technologies in beef color. Moreover, the data presented allow clarifying the meat industry about the potential use of LA preservation on beef.     

Analysis of cooling curve to determine the end point of freezing

The cooling curve method used for the measurement of freezing point of food is further analyzed to explore whether it can be used to identify the end point of freezing or glass transition. In this method, slope of the cooling curve is determined and plotted as a function of time to identify the end point of freezing (T′_m). Initially, the slope is decreased and then reached a minimum value, which is identified as the nucleation of ice. Then the slope is increased until the end point of freezing. The end point of freezing is identified when the slope starts to decrease from its highest value or plateau. Sucrose solutions and starch gels were used to measure its T′_m in identifying validity of the proposed method. The measured values of T′_m by the proposed method is very close to the literature values.     

Xylitol: A Review on Bioproduction,Application, Health Benefits,and Related Safety Issues

Xylitol is a pentahydroxy sugar-alcohol which exists in a very low quantity in fruits and vegetables (plums, strawberries, cauliflower, and pumpkin). On commercial scale, xylitol can be produced by chemical and biotechnological processes. Chemical production is costly and extensive in purification steps. However, biotechnological method utilizes agricultural and forestry wastes which offer the possibilities of economic production of xylitol by reducing required energy. The precursor xylose is produced from agricultural biomass by chemical and enzymatic hydrolysis and can be converted to xylitol primarily by yeast strain. Hydrolysis under acidic condition is the more commonly used practice influenced by various process parameters. Various fermentation process inhibitors are produced during chemical hydrolysis that reduce xylitol production, a detoxification step is, therefore, necessary. Biotechnological xylitol production is an integral process of microbial species belonging to Candida genus which is influenced by various process parameters such as pH, temperature, time, nitrogen source, and yeast extract level. Xylitol has application and potential for food and pharmaceutical industries. It is a functional sweetener as it has prebiotic effects which can reduce blood glucose, triglyceride, and cholesterol level. This review describes recent research developments related to bioproduction of xylitol from agricultural wastes, application, health, and safety issues.     

Cheddar Cheese Ripening and Flavor Characterization: A Review

Cheddar cheese is a biochemically dynamic product that undergoes significant changes during ripening. Freshly made curds of various cheese varieties have bland and largely similar flavors and aroma and, during ripening, flavoring compounds are produced that are characteristic of each variety. The biochemical changes occurring during ripening are grouped into primary events including glycolysis, lipolysis, and proteolysis followed by secondary biochemical changes such as metabolism of fatty acids and amino acids which are important for the production of secondary metabolites, including a number of compounds necessary for flavor development. A key feature of cheese manufacture is the metabolism of lactose to lactate by selected cultures of lactic acid bacteria. The rate and extent of acidification influence the initial texture of the curd by controlling the rate of demineralization. The degree of lipolysis in cheese depends on the variety of cheese and may vary from slight to extensive; however, proteolysis is the most complex of the primary events during cheese ripening, especially in Cheddar-type cheese.