Search Results (11)

Background: Enterococcus faecalis causes serious opportunistic infections in patients with weakened immune defenses, such as individuals suffering from malnutrition. We investigated the effects of Lactiplantibacillus plantarum MPL16 and CRL1506 on the resistance to E. faecalis infection in mice immunosuppressed by protein malnutrition. Methods: Male BALB/c mice received a protein-deficient diet for 21 days, followed by a 7-day renourishment period with a balanced conventional diet (BCD) with or without lactobacilli supplementation. Malnourished controls (MN) and renourished mice were treated with gentamicin for 3 days and then challenged orally with E. faecalis 102. Infection levels in the gut, liver, spleen, and blood, intestinal tissue damage, and the cytokine response were evaluated 2 days after the challenge. Results: Malnourished mice had an impaired ability to produce pro-inflammatory cytokines (TNF, IFN-γ, IL-1β, IL-6, IL-17, and KC) and the regulatory IL-10 in response to the infection compared to mice in the BCD group. The imbalance of inflammatory and regulatory mediators in MN mice favors colonization and invasion by E. faecalis and increases tissue damage, making the disease more severe than in animals renourished with BCD. Supplementing the BCD with L. plantarum strains significantly enhanced resistance to E. faecalis 102 infections, as evidenced by a marked reduction in bacterial loads and intestinal damage. The effect of lactobacilli was associated with enhanced levels of IFN-γ, IL-6, and IL-10 and reduced TNF, IL-1β, IL-17, and KC. Conclusions: Given their efficacy in enhancing host resistance, these Lactiplantibacillus strains hold great promise as a preventive strategy against E. faecalis infections in susceptible individuals. Full article

Wireless sensor networks (WSNs) face a fundamental challenge: their sensors run on batteries, making energy efficiency crucial. While researchers have tried to extend network lifespans by improving routing and access control protocols across different layers, this remains a complex issue. One promising solution is opportunistic routing (OR), which uses multiple nodes to relay data. This approach reduces how long senders must wait for a specific next-hop node and helps prevent data loss from collisions. That said, choosing which nodes should act as forwarders can greatly affect how well the network performs. To tackle this problem, we developed a new approach called FCM-OR, a local density-based forwarder selection algorithm for opportunistic routing in WSNs. Our algorithm is particularly effective in networks where sensors are not evenly spread out and are densely packed. It uses fuzzy c-means (FCM) clustering to smartly pick the best forwarders based on how many nodes are nearby. By focusing on the sender’s immediate surroundings, FCM-OR helps solve the problems that arise when different parts of the network have varying densities of nodes. We also created a new way to measure routing effectiveness called “forwarding rank”. To test how well our protocol works, we ran extensive simulations comparing it to existing methods, including opportunistic routing with duty-cycled WSNs and load-balanced opportunistic routing. The results are clear: FCM-OR significantly improves both network performance and energy efficiency, especially in networks where nodes are not uniformly distributed. Full article

Microbial dysbiosis may manifest as inflammation both orally and in the gastrointestinal tract. Altered oral and gut microbiota composition and decreased diversity have been shown in inflammatory bowel disease (IBD) and periodontal disease (PD). Recent studies have verified transmission of oral opportunistic microbes to the gut. Prebiotics, probiotics, or dietary interventions are suggested to alleviate IBD symptoms in addition to medicinal treatment. Lingonberries contain multiple bioactive molecules, phenolics, which have a broad spectrum of effects, including antimicrobial, anti-inflammatory, antioxidant, anti-proteolytic, and anti-cancer properties. An all-natural product, fermented lingonberry juice (FLJ), is discussed as a potential natural anti-inflammatory substance. FLJ has been shown in clinical human trials to promote the growth of oral lactobacilli, and inhibit growth of the opportunistic oral pathogens Candida, Streptococcus mutans, and periodontopathogens, and decrease inflammation, oral destructive proteolysis (aMMP-8), and dental microbial plaque load. Lactobacilli are probiotic and considered also beneficial for gut health. Considering the positive outcome of these oral studies and the fact that FLJ may be swallowed safely, it might be beneficial also for the gut mucosa by balancing the microbiota and reducing proteolytic inflammation. Full article

Major problems and issues in Internet of Things (IoT) systems include load balancing, lowering operational expenses, and power usage. IoT devices typically run on batteries because they lack direct access to a power source. Geographical conditions that make it difficult to access the electrical network are a common cause. Finding ways to ensure that IoT devices consume the least amount of energy possible is essential. When the network is experiencing high traffic, locating and interacting with the next hop is critical. Finding the best route to load balance by switching to a less crowded channel is hence crucial in network congestion. Due to the restrictions indicated above, this study analyzes three significant issues—load balancing, energy utilization, and computation cost—and offers a solution. To address these resource allocation issues in the IoT, we suggest a reliable method in this study termed Dynamic Energy-Efficient Load Balancing (DEELB). We conducted several experiments, such as bandwidth analysis, in which the DEELB method used 990.65 kbps of bandwidth for 50 operations, while other existing techniques, such as EEFO (Energy-Efficient Opportunistic), DEERA (Dynamic Energy-Efficient Resource Allocation), ELBS (Efficient Load-Balancing Security), and DEBTS (Delay Energy Balanced Task Scheduling), used 1700.91 kbps, 1500.82 kbps, 1300.65 kbps, and 1200.15 kbps of bandwidth, respectively. The experiment’s numerical analysis showed that our method was superior to other ways in terms of effectiveness and efficiency. Full article

One of the Internet’s fastest-growing technologies is cloud computing, which needs each user to share various resources and virtual computers to access the services they demand. The difficulty is in allocating the user’s tasks among the many resources at hand while maintaining a balanced workload. In this work, we present the design of a new scheduling approach for cloud virtual machines in order to process events (related to resource overuse or underuse). This reduces the amount of effort consumed while maintaining the required performance levels in the cloud data center. To evaluate the effectiveness of the approach with real load paths, we conducted an experiment using the open-source cloud computing platform OpenNebula. Full article

Mobile social networks suffer from an unbalanced traffic load distribution due to the heterogeneity in mobility of nodes (humans) in the network. A few nodes in these networks are highly mobile, and the proposed social-based routing algorithms are likely to choose these most “social” nodes as the best message relays. Finally, this could lead to inequitable traffic load distribution and resource utilisation, such as faster battery drain and/or storage consumption of the most (socially) popular nodes. We propose a framework called Traffic Load Distribution Aware (TraLDA) to improve traffic load balancing across network nodes. We present a novel method for calculating node popularity which takes into account both node inherent and social-relations popularity. The former is purely determined by the node’s sociability level in the network, and in TraLDA is computed using the Kalman prediction which considers the node’s periodicity behaviour. However, the latter takes the benefit of interactions with more popular neighbours (acquaintances) to boost the popularity of lower (social) level nodes. Using extensive simulations in the Opportunistic Network Environment (ONE) driven by real human mobility scenarios, we show that our proposed strategy enhances the traffic load distribution fairness of the classical, yet popular social-aware routing algorithms BubbleRap and SimBet without negatively impacting the overall delivery performance. Full article

With the recent evolution of mobile technology, modern devices equipped with multiple communication interfaces have become popular. The multipath transmission control protocol (MPTCP) has evolved to facilitate multiple communication interfaces through a single TCP connection for faster Internet access. MPTCP congestion control algorithms (MPTCP-CCAs) control data flow by fulfilling three design goals, i.e., ensuring improvement over single-path flows, ensuring fairness, and balancing congestion. Current MPTCP-CCAs cannot fulfill these design goals. For example, the opportunistic-linked increase algorithm (OLIA), a well-known MPTCP-CCA in load balancing, often results in low throughput because it cannot properly utilize the underlying network. In addition, the current Internet has a rapidly changing characteristic due to a large amount of short-lived traffic, making it difficult for MPTCP-CCAs to cope. An awareness of prevailing network delay conditions might help MPTCP-CCAs to utilize the network capacity fully. Therefore, we propose dynamic OLIA (D-OLIA), a hybrid MPTCP-CCA that enhances the performance of OLIA by integrating an awareness of the current network delay condition for deciding the congestion window (CWND) decrease factor. We estimate the current network delay condition, i.e., less-congested or congested, by observing the changes in the round-trip-time (RTT). Based on the estimated network delay condition, we decide the CWND decrease factor in real-time for reducing the CWND during packet loss events. We implemented D-OLIA in the Linux kernel and experimented using the Mininet emulator. The emulation results demonstrate that D-OLIA successfully estimates current network delay conditions and results in approximately a 20% increased throughput compared to the original OLIA. Compared to certain MPTCP-CCAs, it also yields a highly improved performance in terms of throughput, RTT, packet retransmissions, and fairness among the MPTCP sub-flows. Full article

Wireless sensor networks (WSNs) have been used for environmental monitoring and reporting for many decades. Energy consumption is a significant research topic because wireless sensor nodes are battery-operated to be highly energy-constrained. Several strategies have been introduced in routing and MAC (Medium Access Control) layer protocols to facilitate energy saving. At the routing layer, an energy-efficient routing protocol, known as opportunistic routing (OR), has been designed to improve efficiency. OR achieves energy efficiency via load-balancing, which forwards packets along multiple routes over WSNs. At the MAC layer, an energy-efficient MAC protocol known as the asynchronous duty-cycled MAC (ADCM) protocol achieves energy saving by turning on and off a sensor node’s transmitter and receiver to eliminate unnecessary energy wastage. These protocols each have their own advantages and disadvantages. OR achieves energy efficiency at the routing layer but it raises an issue at the MAC layer. ADCM achieves energy efficiency at the MAC layer, but it hinders the packet forwarding efficiency of the OR. To attain better energy efficiency, a combination of these two ideas led to the development of OR with asynchronous duty-cycled MAC (OR-ADCM). However, even with better energy efficiency, limitations still exist in combining load-balancing and duty-cycling due to conflicts in the inherent properties of OR and ADCM. In this paper, we present a survey of the evolution of OR-ADCM over WSNs to help the reader better understand and appreciate the details of this tradeoff, which we hope will lead to the development of better protocol designs. Full article

The opportunistic fog radio access network (OF-RAN) is a promising RAN architecture proposed for next-generation cellular networks. OF-RAN extends the current fog RAN (F-RAN) architecture by introducing virtual fog access points (v-FAPs) that can be formed on-demand by a set of resourceful end-user devices available in an opportunistic manner. These devices in the v-FAP collaboratively serve as the service nodes to a resource-limited local client by performing resource-demanding processing tasks on its behalf. Hence, appropriately assigning the client task to the service nodes of the v-FAP, i.e., task-to-node assignment (TNA), is a fundamental problem in OF-RAN. This paper formulates and solves the TNA as a multi-objective optimization problem, with the goals of minimizing energy and latency of the v-FAP, while maximizing fairness (or load balancing) amongst its service nodes by minimizing their maximum load. Full article

This paper presents a novel framework for economic cooling load dispatch in conventional water-cooled chillers. Moreover, information gap decision theory (IGDT) is applied to the optimal chiller loading (OCL) problem to find the optimum operating point of the test system in three decision-making modes: (a) risk-neutral approach, (b) risk-aversion or robustness approach, and (c) risk-taker or opportunistic approach. In the robustness mode of the IGDT-based OCL problem, the system operator enters a desired energy cost value in order to find the most appropriate loading points for the chillers so that the total electricity procurement cost over the study horizon is smaller than or equal to this critical value. Meanwhile, the cooling load increase is maximized to the highest possible level to find the most robust performance of the benchmark grid with respect to the overestimated load. Similarly, the risk-taker optimization method finds the on/off status and the partial load ratio (PLR) of the chillers in order to keep the total energy cost as low as the given cost function. In addition, the minimum value of cooling load decrease can be found while satisfying the refrigeration capacity of the chiller and the load-generation balance constraint. Thus, a mixed-integer non-linear programming problem is solved using the branch and reduce optimization (BARON) tool of the generalized algebraic mathematical modeling system (GAMS) for a five-chiller plant, to demonstrate that IGDT is able to find a good solution in robustness/risk-taker OCL problem. Full article

The ease of deployment and the auto-configuration capabilities of Wireless Sensor Networks (WSNs) make them very attractive in different domains like environmental, home automation or heath care applications. The use of multichannel communications in WSNs helps to improve the overall performance of the network. However, in heavy traffic scenarios, routing protocols should be adapted to allow load balancing and to avoid losing data packets due to congestion and queue overflow. In this paper, we present an Acknowledgement-Based Opportunistic Routing (ABORt) protocol designed for high data rate multichannel WSNs. It is a low overhead protocol that does not rely on synchronization for control traffic exchange during the operational phase of the network. ABORt is an opportunistic protocol that relies on link layer acknowledgements to disseminate routing metrics, which helps to reduce overhead. The performance of ABORt is evaluated using the Cooja simulator and the obtained results show that ABORt has a high packet delivery ratio with reduced packet end-to-end delay compared to two single channel routing protocols and two multichannel routing protocols that use number of hops and expected transmission count as routing metrics. Full article