This paper addresses the stability and L ∞ -gain analysis problem for continuous-time positive fractional-order delay systems with incommensurate orders between zero and one. A necessary and ...sufficient condition is firstly given to characterize the positivity of continuous-time fractional-order systems with bounded time-varying delays. Moreover, by exploiting the monotonic and asymptotic property of the constant delay system by virtue of the positivity, and comparing the trajectory of the time-varying delay system with that of the constant delay system, it is proved that the asymptotic stability of positive fractional-order systems is not sensitive to the magnitude of delays. In addition, it is shown that the L ∞ -gain of a positive fractional-order system is independent of the magnitude of delays and fully determined by the system matrices. Finally, a numerical example is given to show the validity of the theoretical results.
We note that in the literature it is often taken for granted that for fractional-order system without delays, whenever the system trajectory reaches the equilibrium, it will stay there. In fact, this ...is the well-known phenomenon of finite-time stability. However, in this paper, we will prove that for fractional-order nonlinear system described by Caputo’s or Riemann–Liouville’s definition, any equilibrium cannot be finite-time stable as long as the continuous solution corresponding to the initial value problem globally exists. In addition, some examples of stability analysis are revisited and linear Lyapunov function is used to prove the asymptotic stability of positive fractional-order nonlinear systems.
Peripheral nerve injury can lead to partial or complete loss of limb function, and nerve transfer is an effective surgical salvage for patients with these injuries. The inability of deprived cortical ...regions representing damaged nerves to overcome corresponding maladaptive plasticity after the reinnervation of muscle fibers and sensory receptors is thought to be correlated with lasting and unfavorable functional recovery. However, the concept of central nervous system plasticity is rarely elucidated in classical textbooks involving peripheral nerve injury, let alone peripheral nerve transfer. This article is aimed at providing a comprehensive understanding of central nervous system plasticity involving peripheral nerve injury by reviewing studies mainly in human or nonhuman primate and by highlighting the functional and structural modifications in the central nervous system after peripheral nerve transfer. Hopefully, it will help surgeons perform successful nerve transfer under the guidance of modern concepts in neuroplasticity.
Circular RNAs (circRNAs) are long, non-coding RNAs that result from the non-canonical splicing of linear pre-mRNAs. However, the characteristics and the critical role of circRNA in ...co-/post-transcriptional regulation were not well recognized until the "microRNA sponge" function of circRNA is discovered. Recent studies have mainly been devoted to the function of the circular RNA sponge for miR-7 (ciRS-7) and sex-determining region Y (SRY) by targeting microRNA-7 (miR-7) and microRNA-138 (miR-138), respectively. In this review, we illustrate the specific role of circRNAs in a wide variety of cancers and in regulating the biological behavior of cancers via miR-7 or miR-138 regulation. Furthermore, circRNA, together with its gene silencing ability, also shows its potential in RNA interference (RNAi) therapy by binding to target RNAs, which provides a novel perspective in cancer treatment. Thus, this review concerns the biogenesis, biological function, oncogenesis, progression and possible therapies for cancer involving circRNAs.
This paper addresses the L∞-gain analysis problem of positive linear systems with distributed delays. By virtue of the positivity and linearity of the system, we first study the monotonic and ...asymptotic property of the system with distributed delays. Then, by resorting to an auxiliary system without time delay, an explicit expression of the L∞-gain of positive systems with distributed delays is given in terms of system matrices. Moreover, the results are extended to positive systems with distributed delays over a bounded time-varying interval. Finally, a necessary and sufficient condition on the L∞-gain of an asymptotically stable positive system with distributed delays is presented via linear programming.
With the rapid development of cloud computing, cloud storage has been accepted by an increasing number of organizations and individuals, therein serving as a convenient and on-demand outsourcing ...application. However, upon losing local control of data, it becomes an urgent need for users to verify whether cloud service providers have stored their data securely. Hence, many researchers have devoted themselves to the design of auditing protocols directed at outsourced data. In this paper, we propose an efficient public auditing protocol with global and sampling blockless verification as well as batch auditing, where data dynamics are substantially more efficiently supported than is the case with the state of the art. Note that, the novel dynamic structure in our protocol consists of a doubly linked info table and a location array. Moreover, with such a structure, computational and communication overheads can be reduced substantially. Security analysis indicates that our protocol can achieve the desired properties. Moreover, numerical analysis and real-world experimental results demonstrate that the proposed protocol achieves a given efficiency in practice.
We are entering an era of great expectations towards our cities. The vision of “smart city” has been pursued worldwide to transform urban habitats into superior efficiency, quality, and ...sustainability. This phenomenon prompts us to ponder what role the scholars in operations management (OM) can assume. In this essay, we express our initial thoughts on expanding OM to the smart‐city scope. We review smart‐city initiatives of governments, industry, national laboratories and academia. We argue that the smart‐city movement will transition from the tech‐oriented stage to the decision‐oriented stage. Hence, a smart city can be perceived as a system scope within which planning and operational decisions are orchestrated at the urban scale, reflective of multi‐dimensional needs, and adaptive to massive data and innovation. The benefits of studying smart‐city OM are manifold and significant: contributing to deeper understanding of smart cities by providing advanced analytical frameworks, pushing OM knowledge boundaries (such as data‐driven decision making), and empowering the OM community to deliver much broader impacts than before. We discuss several research opportunities to embody these thoughts, in the interconnected contexts of smart buildings, smart grid, smart mobility and new retail. These opportunities arise from the increasing integration of systems and business models at the urban scale.
The Triple‐A supply chain (Lee 2004) has become one of the most influential concepts for practitioners and researchers in supply chain management. It stipulates that supply chains should strive to ...improve along the dimensions of agility, adaptability, and alignment, as opposed to focusing exclusively on cost and efficiency improvements. While various strategies have since been adopted across different industries to foster the Triple‐A, the digitalization movement poses both new challenges and opportunities for developing Triple‐A supply chains. In this article, we shall discuss an emerging mode of supply chain innovation, known as the consumer‐to‐manufacturer (C2M) model, and how it enables new possibilities for achieving Triple‐A “digital” supply chains. C2M establishes digital links between end consumers and upstream manufacturers and product designers, and provides a variety of tactics to shorten the information flow process of the supply chain. Our discussion focuses on the implementation of C2M at JD.com, a leading online retailer in China.
The scavenger receptor, class B type 1 (SR-B1), is a multiligand membrane receptor protein that functions as a physiologically relevant high-density lipoprotein (HDL) receptor whose primary role is ...to mediate selective uptake or influx of HDL-derived cholesteryl esters into cells and tissues. SR-B1 also facilitates the efflux of cholesterol from peripheral tissues, including macrophages, back to liver. As a regulator of plasma membrane cholesterol content, SR-B1 promotes the uptake of lipid soluble vitamins as well as viral entry into host cells. These collective functions of SR-B1 ultimately affect programmed cell death, female fertility, platelet function, vasculature inflammation, and diet-induced atherosclerosis and myocardial infarction. SR-B1 has also been identified as a potential marker for cancer diagnosis and prognosis. Finally, the SR-B1-linked selective HDL-cholesteryl ester uptake pathway is now being evaluated as a gateway for the delivery of therapeutic and diagnostic agents. In this review, we focus on the regulation and functional significance of SR-B1 in mediating cholesterol movement into and out of cells.
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