Molecular circuit for exponentiation based on the domain coding strategy

DNA strand displacement (DSD) is an efficient technology for constructing molecular circuits. However, system computing speed and the scale of logical gate circuits remain a huge challenge. In this paper, a new method of coding DNA domains is proposed to carry out logic computation. The structure of DNA strands is designed regularly, and the rules of domain coding are described. Based on this, multiple-input and one-output logic computing modules are built, which are the basic components forming digital circuits. If the module has n inputs, it can implement 2n logic functions, which reduces the difficulty of designing and simplifies the structure of molecular logic circuits. In order to verify the superiority of this method for developing large-scale complex circuits, the square root and exponentiation molecular circuits are built. Under the same experimental conditions, compared with the dual-track circuits, the simulation results show that the molecular circuits designed based on the domain coding strategy have faster response time, simpler circuit structure, and better parallelism and scalability. The method of forming digital circuits based on domain coding provides a more effective way to realize intricate molecular control systems and promotes the development of DNA computing

eCOTS: Efficient and Cooperative Task Sharing for Large-Scale Smart City Sensing Application

With the pervasive use of mobile devices and increasingly computational ability, more concrete and deeper collaborations among mobile users are becoming possible and needed. However, most of the studies fail to consider load balancing requirement among mobile users. When tasks are unevenly distributed, the processing time as well as energy consumption will be extremely high on some devices, which will inevitably counterweight the benefits from incentive mechanism and task scheduling scheme. In this work, we propose eCOTS (Efficient and Cooperative Task Sharing for Large-scale Smart City Sensing Application). We leverage the “balls and bins” theory for task assignment, where d mobile users in contact range are investigated, and select the least loaded one among the d users. It has been proved that such simple case can effectively reduce the largest queueing length from θ ( log n / log log n ) to θ ( log log n / log d ) . Simulation and real-trace driven studies have shown that, eCOTS can effectively improve the balancing effects in typical network scenarios, even the energy level and computational capability are diverse. In simulation study, eCOTS can reduce the gap between the maximum and minimum queueing lengths up to 5× and over 2× in real trace data evaluations

Ontogenetic Development of Digestive Enzymes in Orange-Spotted Grouper (Epinephelus coioides, Hamilton, 1822) Larvae

The digestive physiology of orange-spotted grouper (Epinephelus coioides) was studied by assessing the specific and total activities of alkaline phosphatase, amylase, lipase, chymotrypsin, and trypsin, from hatching to 34 days post-hatching (DPH). From the onset of exogenous feeding, total alkaline phosphatase, amylase, lipase, and chymotrypsin activity fluctuated then sharply increased from 18 to 34 DPH. In contrast to other enzymes, the specific and total activity of trypsin remained at a low level from 1-26 DPH, and reached the maximum on 30 DPH. Digestive enzymes activity indicated that orange-spotted grouper were able to digest proteins, lipids, and carbohydrates at an early developmental stage. Results from the present study will improve understanding of the ontogeny of orange-spotted grouper during the larval stage, and provide a guide to hatchery feeding of this economically important fish

False Negative Problem of Counting Bloom Filter

Bloom filter is effective, space-efficient data structure for concisely representing a data set and supporting approximate membership queries. Traditionally, researchers often believe that it is possible that a Bloom filter returns a false positive, but it will never return a false negative under well-behaved operations. By investigating the mainstream variants, however, we observe that a Bloom filter does return false negatives in many scenarios. In this work, we show that the undetectable incorrect deletion of false positive items and detectable incorrect deletion of multiaddress items are two general causes of false negative in a Bloom filter. We then measure the potential and exposed false negatives theoretically and practically. Inspired by the fact that the potential false negatives are usually not fully exposed, we propose a novel Bloom filter scheme, which increases the ratio of bits set to a value larger than one without decreasing the ratio of bits set to zero. Mathematical analysis and comprehensive experiments show that this design can reduce the number of exposed false negatives as well as decrease the likelihood of false positives. To the best of our knowledge, this is the first work dealing with both the false positive and false negative problems of Bloom filter systematically when supporting standard usages of item insertion, query, and deletion operations