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Plant roots explore the soil for water and nutrients, thereby determining plant fitness and agricultural yield, as well as determining ground substructure, water levels, and global carbon sequestration. The colonization of the soil requires investment of carbon and energy, but how sugar and energy signaling are integrated with root branching is unknown. Here, we show through combined genetic and chemical modulation of signaling pathways that the sugar small-molecule signal, trehalose-6-phosphate (T6P) regulates root branching through master kinases SNF1-related kinase-1 (SnRK1) and Target of Rapamycin (TOR) and with the involvement of the plant hormone auxin. Increase of T6P levels both via genetic targeting in lateral root (LR) founder cells and through light-activated release of the presignaling T6P-precursor reveals that T6P increases root branching through coordinated inhibition of SnRK1 and activation of TOR. Auxin, the master regulator of LR formation, impacts this T6P function by transcriptionally down-regulating the T6P-degrader trehalose phosphate phosphatase B in LR cells. Our results reveal a regulatory energy-balance network for LR formation that links the 'sugar signal' T6P to both SnRK1 and TOR downstream of auxin. [ABSTRACT FROM AUTHOR]

The development of sensing cloud provides new network architecture and optimization ideas for wireless sensor networks. In this paper, we study the service performance problems of sensor clouds in multi-user and multi-task service scenarios and optimize the sensing task distribution strategy in sensor clouds. Based on the characteristics of sensing task issuance and execution, a load-aware energy efficient clustering service algorithm for sensing cloud is proposed by introducing the measurement of regional load in the process of sensing cloud network services. The algorithm achieves load balancing and energy consumption balancing by improving the existing energy efficient clustering algorithm. The algorithm selects the best cluster head node by considering the energy of each sensor node and the distance from the data center. In addition, the algorithm assigns service tasks to the nodes that are most suitable to serve the current task based on the regional service load and selects the minimum number of nodes to collect packets to meet the user's requirements. The algorithm is verified through simulation experiments to be better than similar algorithms in key service metrics such as node energy consumption, node survival rate, and service area coverage. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to investigate accurate and effective experimental methods for measuring the frictional loss of bearings (FLB) in mechanical systems and to measure the effect of various operating parameters on the frictional loss of high-speed mechanical systems. Design/methodology/approach: Two novel methods were studied in this paper to measure the FLB: the free-deceleration method and the energy-balance method. A special high-speed motorised spindle and a friction loss test rig were designed and built to measure the effects of rotational speed, lubrication, preload and operating temperature on the FLB. Findings: The experimental results showed that the frictional torque of bearings increases initially but then decreases with an increase in rotational speed. Similarly, the FLB decreases initially and then increases with an increase in temperature because of the influence of the viscosity–temperature relationship of the lubricant and the thermomechanical coupling factor. The optimal lubricant flow was determined, and the effectiveness of a novel preload online adjusting device was verified through experiments. Originality/value: The research results of this paper provide the basis and methods for the measurement, reduction and prediction of the FLB in mechanical systems. [ABSTRACT FROM AUTHOR]

This paper presents a review of tree based energy balanced routing protocols in wireless sensor networks. General self-organizing tree branching energy balance (GSTEB) routing protocol outperforms many protocols in terms of network lifetime and energy consumption per round. In GSTEB, BS assigns a root node and broadcasts its ID and coordinates in the selected network of sensor nodes. Here leaf node makes use of beacon instead of packets thus decreasing the number of bits. Subsequently, each node selects its parent node by considering its own information or considering the neighbors information thus it makes GSTEB a dynamic routing protocol. Also make efforts to overcome load balancing problem as it is much difficult to attain the load balance on each and every node. [ABSTRACT FROM AUTHOR]

Wireless sensor network (WSN) is a system composed of a large number of low-cost micro-sensors. This network is used to collect and send various kinds of messages to a base station (BS). WSN consists of low-cost nodes with limited battery power, and the battery replacement is not easy for WSN with thousands of physically embedded nodes, which means energy efficient routing protocol should be employed to offer a long-life work time. To achieve the aim, we need not only to minimize total energy consumption but also to balance WSN load. Researchers have proposed many protocols such as LEACH, HEED, PEGASIS, TBC and PEDAP. In this paper, we propose a General Self-Organized Tree-Based Energy-Balance routing protocol (GSTEB) which builds a routing tree using a process where, for each round, BS assigns a root node and broadcasts this selection to all sensor nodes. Subsequently, each node selects its parent by considering only itself and its neighbors’ information, thus making GSTEB a dynamic protocol. Simulation results show that GSTEB has a better performance than other protocols in balancing energy consumption, thus prolonging the lifetime of WSN. [ABSTRACT FROM PUBLISHER]

Energy-efficient data gathering in multi-hop wireless sensor networks was studied, considering that different node produces different amounts of data in realistic environments. A novel dominating set based clustering protocol (DSCP) was proposed to solve the data gathering problem in this scenario. In DSCP, a node evaluates the potential lifetime of the network (from its local point of view) assuming that it acts as the cluster head, and claims to be a tentative cluster head if it maximizes the potential lifetime. When evaluating the potential lifetime of the network, a node considers not only its remaining energy, but also other factors including its traffic load, the number of its neighbors, and the traffic loads of its neighbors. A tentative cluster head becomes a final cluster head with a probability inversely proportional to the number of tentative cluster heads that cover its neighbors. The protocol can terminate in O( n/lg n) steps, and its total message complexity is O( n/lg n). Simulation results show that DSCP can effectively prolong the lifetime of the network in multi-hop networks with unbalanced traffic load. Compared with EECT, the network lifetime is prolonged by 56.6% in average. [ABSTRACT FROM AUTHOR]

Aiming at the data unbalance of sensor nodes in the wireless sensor networks (WSN), this paper mainly studies the data gathering algorithm for linear WSNs. As the data amount varies from the time spent on data gathering of entire network minimal, it is a key factor to balance energy consumption and further prolong the network lifetime. Therefore, this paper proposes a TDMA scheduling algorithm for general k-hop networks, and takes detail performance analysis on the algorithm. Furthermore, we present the method of selecting the optimal hop-count and its formula as well as the formula of the number of timeslots required for converge-cast in order to maximize network lifetime. Finally, we obtain some general conclusions of network optimization based on the theoretical analysis and simulations. Compared with the 1-hop algorithm in (C. Florens and R. McEliece, Packets Distribution Algorithms for Sensor Networks, IEEE INFOCOM, San Diego, pp. 1063–1072, 2003), the TDMA scheduling algorithm for the general k-hop network proposed in our paper is more universal and has more practical application value. [ABSTRACT FROM AUTHOR]