History and Conservation of Rockwork in Gardens of Imperial China

From the last century, especially from the 1950s onward, many historical gardens in China have been repaired and restored. Although the aim was to preserve the cultural heritage, many of these gardens were modified during the conservation projects. This thesis focuses on one of the typical garden features, the rockwork. Like gardens, historic rockwork in China has often been transformed from a particular into a generic style. In view of this phenomenon, this thesis focuses on answering the following questions: How have the original appearance and states of rockwork been maintained in conservation projects? How can conservation practice be improved in order to accomplish more authentic restoration? Guided by these two main questions, this thesis aims to contribute to a more authentic restoration and conservation practice. At the beginning, with a critical review of the history of rockwork in China, evidence is shown that preferences in rockwork changed over time. Various trends and most common characteristics of different periods are also identified. The subsequent analysis of legislation and guidelines related to the conservation of rockwork reveal conservation principles during and since the twentieth century, which continue to develop and change up to the present day. An understanding of the various trends and conservation principles provides a solid basis for the evaluation of conservation projects. Four individual cases were then studied in depth to investigate the conservation treatments applied to historic rockwork and the influences on the retention of their original appearance and state. These case studies demonstrate that historic rockwork has been modified to various extents during the conservation process, its historic significance has been overlooked, and some have been restored based on current aesthetic standards. Even so, some of these projects are still considered as good examples to be followed. Based on the problems and good practices identified in the case studies, specific recommendations are finally provided, to prevent the repetition of past mistakes, and to guide and improve future conservation practices

A neural network-based direct adaptive fault tolerance flight control for control surface damage

AbstractIn order to enhance the reliability of flight control systems, a new neural network-based direct adaptive fault tolerance control was proposed for flight control system in the presence of control surface damage. Based on the accuracy approach of neural network, a fault parameter identification models were built to constitute hybrid compensator in order to ensure the strictly positive real of the failure flight control systems in the inner control loop. In the outer loop, a common direct adaptive controller was designed. The scheme was illustrated through simulations using an aircraft. The results show that an aircraft has also good dynamic performance in the control surface damage

Genetically modifying Arabidopsis thaliana with a gene from Drought-tolerant Xerophyte Larrea tridentata (Creosote Bush)

L. tridentata, or desert creosote bush, is a xerophytic C3 plant native to the American Southwest, and is known to have evolutionarily developed sophisticated cellular mechanisms to deal with periods of intense abiotic stress. Particularly, complex signaling pathways in L. tridentata allow it to survive in periods of severe water deficiency. Through the findings of Zou et al. [5,6], LtWRKY21 synergistically works with abscisic acid (ABA) to transactivate both ABA-inducible HVA1 and HVA22 promoters. In addition, as ABA and gibberellic acid (GA) pathways are known to act antagonistically. Expectantly, the findings of Zou et al. suggest that LtWRKY21 activates ABA signaling pathways and represses GA signaling pathways [5,6]. More importantly, the LtWRKY21 transcription factor’s synergy with ABA is directly linked to some remarkable molecular adaptations of L. tridentata, some of which include stomatal closure to prevent transpiration, and slowing down gene expression to withstand dehydration [6]. To examine some of these mechanisms, the model plant Arabidopsis thaliana will be transformed with the LtWRKY21 coding region via Agrobacterium-mediated transformation. Successful transformants will be selected and the subsequent generation of transgenic plants will be assayed. Both phenotypic (screening) and genotypic (qRT-PCR and Southern Blot) examination will allow the function and expression patterns of LtWRKY21 to be elucidated under simulated drought. In order for LtWRKY21 to be successfully transformed into Arabidopsis, a tumor-inducing (Ti) plasmid must be engineered to carry LtWRKY21

DUNE: Improving Accuracy for Sketch-INT Network Measurement Systems

In-band Network Telemetry (INT) and sketching algorithms are two promising directions for measuring network traffics in real time. To combine sketch with INT and preserve their advantages, a representative approach is to use INT to send a switch sketch in small pieces (called sketchlets) to end-host for reconstructing an identical sketch. However, in this paper, we reveal that when naively selecting buckets to sketchlets, the end-host reconstructed sketch is inaccurate. To overcome this problem, we present DUNE, an innovative sketch-INT network measurement system. DUNE incorporates two key innovations: First, we design a novel scatter sketchlet that is more efficient in transferring measurement data by allowing a switch to select individual buckets to add to sketchlets; Second, we propose lightweight data structures for tracing "freshness" of the sketch buckets, and present algorithms for smartly selecting buckets that contain valuable measurement data to send to end-host. We theoretically prove the effectiveness of our proposed methods, and implement a prototype on commodity programmable switch. The results of extensive experiments driven by real-world traffics on DUNE suggest that our proposed system can substantially improve the measurement accuracy at a trivial cost.Comment: Technical report for the paper published in IEEE INFOCOM 202

Observation of a thermoelectric Hall plateau in the extreme quantum limit

The thermoelectric Hall effect is the generation of a transverse heat current upon applying an electric field in the presence of a magnetic field. Here we demonstrate that the thermoelectric Hall conductivity $\alpha_{xy}$ in the three-dimensional Dirac semimetal ZrTe$_5$ acquires a robust plateau in the extreme quantum limit of magnetic field. The plateau value is independent of the field strength, disorder strength, carrier concentration, or carrier sign. We explain this plateau theoretically and show that it is a unique signature of three-dimensional Dirac or Weyl electrons in the extreme quantum limit. We further find that other thermoelectric coefficients, such as the thermopower and Nernst coefficient, are greatly enhanced over their zero-field values even at relatively low fields.Comment: 17+21 pages, 3+14 figures; published versio

Autophagy in ischemic stroke: role of circular RNAs

Stroke, a central nervous system (CNS) injury, is responsible for the second leading cause of death in the world, bringing a great burden on the world. Stroke is normally divided into ischemic and hemorrhagic stroke, among which ischemic stroke takes up 87% proportion. Accumulating evidence has denoted a rather pivotal role for autophagy in the pathogenesis of ischemic stroke, which is activated in neuronal cells, glial cells, and endothelial cells. Besides, circular RNAs (circRNAs), a novel type of epigenetic regulation, are highly expressed in the CNS and are involved in the process of CNS diseases, which is regarded as an important molecular mechanism in ischemic stroke. Meanwhile, circRNA and autophagy have a significant correlation. The intracellular signaling pathways regulating autophagy can either restrain or activate autophagy. However, under the circumstances of ischemic stroke, the precise communication between circRNA and stroke is largely unknown. This review aims to provide a summary of the relationship between circRNA, autophagy, and ischemic stroke, as well as the current research advancements in understanding how circRNA regulates autophagy in the context of stroke

Temperature- and field angular-dependent helical spin period characterized by magnetic dynamics in a chiral helimagnet MnNb3S6MnNb_3S_6

The chiral magnets with topological spin textures provide a rare platform to explore topology and magnetism for potential application implementation. Here, we study the magnetic dynamics of several spin configurations on the monoaxial chiral magnetic crystal $MnNb_3S_6$ via broadband ferromagnetic resonance (FMR) technique at cryogenic temperature. In the high-field forced ferromagnetic state (FFM) regime, the obtained frequency f vs. resonance field Hres dispersion curve follows the well-known Kittel formula for a single FFM, while in the low-field chiral magnetic soliton lattice (CSL) regime, the dependence of Hres on magnetic field angle can be well-described by our modified Kittel formula including the mixture of a helical spin segment and the FFM phase. Furthermore, compared to the sophisticated Lorentz micrograph technique, the observed magnetic dynamics corresponding to different spin configurations allow us to obtain temperature- and field-dependent proportion of helical spin texture and helical spin period ratio L(H)/L(0) via our modified Kittel formula. Our results demonstrated that field- and temperature-dependent nontrivial magnetic structures and corresponding distinct spin dynamics in chiral magnets can be an alternative and efficient approach to uncovering and controlling nontrivial topological magnetic dynamics.Comment: 29 pages (including Supporting Information), 7 figures, accepted by SCIENCE CHINA Physics, Mechanics & Astronom