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This paper presents a new method for simultaneous synthesis of dynamic controller and static anti-windup compensator for saturated Lipschitz systems. Thanks to the reformulated Lipschitz property, the Lipschitz systems can be transformed into LPV (linear parameter-varying) systems whose system matrices are affine in a parameter matrix. Based on the modified sector condition dealing with saturation nonlinearity, the design of a nonlinear anti-windup-based controller leads to the solvability of a set of bilinear matrix inequalities (BMI) on the vertices of a bounded convex set which can be solved by the so-called iterative linear matrix inequality (ILMI) algorithm. A numerical example is presented to illustrate the effectiveness of the proposed method.

Renal cell carcinoma (RCC) is a common tissue tumor that occurs across all age groups and has become one of the types of cancer with the fastest increasing incidence. Due to the resistance of RCC chemo- and radiotherapy, surgery is the only currently effective treatment. Therefore, specific markers for the diagnosis and prognosis of RCC are expected to result in novel methods of treatment. Ecto-5′-nucleotidase, also termed cluster of differentiation (CD)73, is a protein that is activated in several types of aggressive cancer and may promote cancer progression. CD73 was examined in the present study to determine the association between the protein and RCC. The expression levels of CD73 in 159 RCC tissue sections and 30 paratumorous normal renal tissue samples obtained from 235 patients that underwent nephrectomy were examined by immunohistochemical staining. By contrast, the expression level of P-glycoprotein (P-gp), a potential prognostic factor in RCC, was also examined in 85 RCC and 13 normal tissue samples. Intense CD73 expression was identified in 75 out of 159 RCC cell membranes compared with normal renal tissues. In contrast, there was high P-gp expression in the blood vessels of 42 out of 85 RCC tissues and there was no significant difference between the P-gp expression identified in RCC cells (34 out of 85) and the cell membrane of normal renal cells (2 out of 13). The expression level of CD73 in RCC cells was significantly associated with tumor type, tumor node metastasis (TNM) stage, and tumor grade. However, the expression of P-gp in RCC cells was only associated with the TNM stage and tumor grade. Using a multivariable Cox regression analysis, it was found that the median survival rate of RCC patients with intense CD73 expression in RCC cells was 62.06±5.35 months, which was drastically shorter compared with rare CD73 expression (103.72±3.67 months). In conclusion, the expression level of CD73 is significantly associated with RCC tumor progression and may serve as a favorable marker for the diagnosis and prognosis of RCC, in addition to being a therapeutic target for the treatment of RCC.

Exposure to radiofrequency fields (RF) has been reported to induce adverse effects on testosterone production and its daily rhythm. However, the mechanisms underneath this effect remain unknown. In this study, male mice were exposed to 1800 MHz radiofrequency fields (RF, 40 μW/cm2 power intensity and 0.0553 W/Kg SAR) 2 h per day for 32 days. The data suggested that RF exposure: (i) significantly reduced testosterone levels, (ii) altered the expression of genes involved in its synthesis (Star, P450scc, P450c17 and 3β-Hsd) in testicular tissue, (iii) significantly reduced regulatory protein CaMKI/RORα. Similar observations were also made in cultured primary Leydig cells exposed in vitro to RF. However, all of these observations were blocked by CaMK inhibitor, KN-93, and ionomycin reversed the down-regulation effects on intracellular [Ca2+]i and CaMKI/RORα expression induced by RF exposure. Thus, the data provided the evidence that RF-induced inhibition of testosterone synthesis might be mediated through CaMKI/RORα signaling pathway. Capsule: CaMKI/RORα signaling pathway was involved in the inhibition of testosterone synthesis induced by RF exposure.

Radiation-induced bystander effects are well-established phenomena, in which DNA damage responses are induced not only in the directly irradiated cells but also in the non-irradiated bystander cells through intercellular signal transmission. Recent studies hint that bystander effects are possibly mediated via small non-coding RNAs, especially microRNAs. Thus, more details about the roles of microRNA in bystander effects are urgently needed to be elucidated. Here we demonstrated that bystander effects were induced in human fetal lung MRC-5 fibroblasts through medium-mediated way by different types of radiation. We identified a set of differentially expressed microRNAs in the cell culture medium after irradiation, among which the up-regulation of miR-21 was further verified with qRT-PCR. In addition, we found significant upregulation of miR-21 in both directly irradiated cells and bystander cells, which was confirmed by the expression of miR-21 precursor and its target genes. Transfection of miR-21 mimics into non-irradiated MRC-5 cells caused bystander-like effects. Taken together, our data reveals that miR-21 is involved in radiation-induced bystander effects. Elucidation of such a miRNA-mediated bystander effect is of utmost importance in understanding the biological processes related to ionizing radiation and cell-to-cell communication.

The mechanisms of radiation-induced bystander effects (RIBE) have been investigated intensively over the past two decades. Although quite a few reports demonstrated that cytokines such as TGF-β1 are induced within the directly irradiated cells and play critical roles in mediating the bystander effects, little is known about the signaling pathways that occur in bystander cells. The crucial question as to why RIBE signals cannot be infinitely transmitted, therefore, remains unclear. In the present study, we showed that miR-663, a radiosensitive microRNA, participates in the regulation of biological effects in both directly irradiated and bystander cells via its targeting of TGF-β1. MiR-663 was downregulated, while TGFB1 was upregulated in directly irradiated cells. The regulation profile of miR-663 and TGFB1, on the other hand, was reversed in bystander cells, in which an elevated miR-663 expression was exhibited and led to downregulation of TGF-β1. Further studies revealed that miR-663 interacts with TGFB1 directly and that through its binding to the core regulation sequence, miR-663 suppresses the expression of TGFB1. Based on the results, we propose that miR-663 inhibits the propagation of RIBE in a feedback mode, in which the induction of TGF-β1 by reduced miR-663 in directly irradiated cells leads to increased level of miR-663 in bystander cells. The upregulation of miR-663 in turn suppresses the expression of TGF-β1 and limits further transmission of the bystander signals.

Space exploration represents great challenge to astronauts’ health because of the uncertain risk of carcinogenesis caused by space radiation, in which high-charge and -energy (HZE) particles should be the most harmful components. Although there are a number of researches confirming that HZE particles have more severe biological effects including tumorigenesis than low-LET radiations, it is still very hard to accurately estimate the cancer risk of space HZE radiation due to the lack of suitable epidemiological data on exposures to low-dose HZE particle irradiation. Ground-based experiments on high-energy heavy ion accelerators might be appropriate complement for understanding the risk of space radiation. On the other hand, effective countermeasures to reduce the radiation damage are essential to manned space exploration. Up to now, shielding is still the most practical way to attenuate biological responses of space radiation. However, the knowledge on the biological effects of secondary particles produced by the interaction of HZE particles with shielding materials is required for space shielding design. This review will discuss the issues of space HZE particles and the biological effects of secondary particles produced by the interaction of space radiation and shielding materials.

During a long-term exploration in space, astronauts will be constantly exposed to space radiation which contains various types of low dose-rate heavy particles. Although the fluxes of these heavy ions are very small, the heavy ions can cause severe biological effects including early effects and late effects. This short review will discuss the biological effects induced by space radiation and introduce a new anti-radiation agent we have developed. We synthesized a class of reactive oxygen species scavengers called GANRA-5 with lowly toxic but high radio-protective effect to both heavy ions and X-rays. GANRA-5 can protect cells from X-rays and carbon ions induced cell killing by significantly reducing the amount of free radical production therefor reduce double-strand breaks and genomic instability. In vivo, GANRA-5 can effectively protect the mice from the damage induced by X-rays irradiation by enhancing superoxide dismutase activities. In brief, GANRA-5 is potentially applicable in space flight.

This paper addresses the robust and accurate trajectory tracking problem for unmanned helicopters in the presence of model uncertainties and external disturbances. First, the helicopter's model is simplified to a six-degrees-of-freedom rigid body augmented with a simplified rotor dynamic model, with the model uncertainties and the external disturbances being treated as lumped unknown disturbances. Second, a nonlinear disturbance observer is designed to estimate this lumped disturbance. Then, a backstepping controller with disturbance compensation is designed to ensure robust and highly trajectory tracking. After that, the theoretical analysis of the efficiency of the designed disturbance observer-based backstepping controller (Backstepping+DO) is shown by the Lyapunov theory. Finally, simulation results and conclusions are presented and discussed.

High atomic number and high-energy (HZE) particles in deep space are of low abundance but substantially contribute to the biological effects of space radiation. Shielding is so far the most effective way to partially protect astronauts from these highly penetrating particles. However, simulated calculations and measurements have predicted that secondary particles resulting from the shielding of cosmic rays produce a significant fraction of the total dose and dose equivalent. In this study, we investigated the biological effects of secondary radiation with two cell types, and with cells exposed in different phases of the cell cycle, by comparing the biological effects of a 200 MeV/u iron beam with a shielded beam in which the energy of the iron ion beam was decreased from 500 MeV/u to 200 MeV/u with PMMA, polyethylene (PE), or aluminum. We found that beam shielding resulted in increased induction of 53BP1 foci and micronuclei in a cell-type-dependent manner compared with the unshielded 200 MeV/u Fe ion beam. These findings provide experimental proof that the biological effects of secondary particles resulting from the interaction between HZE particles and shielding materials should be considered in shielding design.

This paper presents a particle filter-based visual tracking method with online feature selection mechanism. In color-based particle filter algorithm the weights of particles do not always represent the importance correctly, this may cause that the object tracking based on particle filter converge to a local region of the object. In our proposed visual tracking method, the Bhattacharyya distance and the local discrimination between the object and background are used to define the weights of the particles, which can solve the existing local convergence problem. Experiments demonstrates that the proposed method can work well not only in single object tracking processes but also in multiple similar objects tracking processes.

Identification of a specific biomarker for cancer stem cells (CSCs) is of potential applications in the development of effective therapeutic strategies for renal cell carcinoma (RCC). In this study, both the RCC cell line 786-O and surgically removed clear cell RCC (ccRCC) tissues were implemented to grew as spheroids in serum-free medium supplemented with mitogens. This subpopulation possessed key characteristics defining CSCs. We also identified that surgically removed ccRCC tissues were heterogenic and there was a subpopulation of cells that was highly stained with rhodamine-123. Based on membrane-proteomic analyses, CD73 was identified as a candidate biomarker. We further found that CD73high cells were highly tumorigenic. As few as 100 CD73high cells were capable of forming xenograft tumors in non obese diabetic/severe combined immunodeficiency disease mice, whereas 1 × 105 CD73low cells did not initiate tumor formation. During successive culture, the CD73high population regenerated both CD73high and CD73low cells, whereas the CD73low population remained low expression level of CD73. Furthermore, the CD73high cells were more resistant to radiation and DNA-damaging agents than the CD73low cells, and expressed a panel of 'stemness' genes at a higher level than the CD73low cells. These findings suggest that a high level of CD73 expression is a bona fide biomarker of ccRCC stem-like cells. Future research will aim at the elucidation of the underlying mechanisms of CD73 in RCC development and the distinct aspects of ccRCC stem-like cells from other tumor types.

The robust controller is designed for certain BTT missile which is equipped with grid fin. In order to design the controller of BTT missile, the aerodynamic force of grid fin is analyzed when the grid fin rotates in flying, then the aerodynamic force and aerodynamic moment along with movement equations are linearized based on the small perturbation linear theory, the beginning state of the cruise is chosen as the feature point, and then the dynamical coefficient are calculated, then the longitudinal and lateral perturbation equations are established. The dynamic responses of each motion deviation under the longitudinal and lateral free disturbance are obtained through solving the perturbation equations. The transfer functions and the dynamic responses under the step deflection of grid fin are derived, then the dynamic characteristics of the missile can be obtained. The results indicate that the grid fin can provide favorable stability. The H ∞ controller of pitch and lateral bank channels are designed based on dynamic characteristics analysis, the simulation results indicate that the system dynamic performance can satisfy the requirement, and H ∞ controller has a fine robustness for the parametric variation.

In order to simulate the in-orbit movement of formation satellites, the unmanned helicopter is utilized to set up the microgravity environment relative navigation ground simulation platform. The platform can provide the movement of six degrees of freedom and can simulate the formation satellite flying in three-dimensional space. The test platform includes host computer system, communication system, UAVs formation control system, satellite attitude simulation system, and so on. Sensors are equipped with laser radar and visible light cameras. Formation control and navigation of multi-body can be achieved under complex network environment. The platform can be used for the test of satellite autonomous formation simulation, joint fleet navigation, and so on. The algorithm of multi-body formation, multi-source and multi-target tracking based on sensor network, multi-body navigation and remote control can be verified on this platform.

This study considers the leader-following formation problem for the nonholonomic mobile robots, where the dynamics of the leader robot is unknown to the follower. First, the leader-following formation is transformed into a special trajectory tracking. Then neural network observer by the follower robot is designed to estimate the dynamics of the leader robot and based on multiple sliding surface technique control laws are designed for the follower robot to track the leader robot in the desired separation and bearing. The efficiency of the control law design is illustrated by formal proof and simulation results. Finally, conclusions are discussed.

We address the problem of environmental contour line tracking for a class of autonomous vehicles. A reference velocity is designed for the autonomous vehicles to do contour line tracking. Based on Lashall invariance principle, an ideal controller is designed for the vehicle with ideal model and ideal information about the environmental concentration function to track the desired contour line. For the vehicle with possibly modeling uncertainty, we combine a neural controller containing a wavelet neural network (WNN) identifier with a robust control to construct a robust adaptive WNN control for the vehicle to track the desired environmental contour line. Then we give theoretical proof of the efficiency of the designed robust adaptive WNN control. Simulation results and conclusion are presented and discussed.

This paper addresses the robust trajectory tracking problem for a robot manipulator in the presence of uncertainties and disturbances. First, a neural network-based sliding mode adaptive control (NNSMAC), which is a combination of sliding mode technique, neural network (NN) approximation and adaptive technique, is designed to ensure trajectory tracking by the robot manipulator. It is shown using the Lyapunov theory that the tracking error asymptotically converge to zero. However, the assumption on the availability of the robot manipulator dynamics is not always practical. So, an NN-based adaptive observer is designed to estimate the velocities of the links. Next, based on the observer, a neural network-based sliding mode adaptive output feedback control (NNSMAOFC) is designed. Then it is shown by the Lyapunov theory that the trajectory tracking errors, the observer estimation errors asymptotically converge to zero. The effectiveness of the designed NNSMAC, the NN-based adaptive observer and the NNSMAOFC is illustrated by simulations.

MicroRNAs (miRNAs) are highly conserved small non-coding RNAs that alter protein expression and regulate multiple intracellular processes including cellular stress response. We previously uncovered several novel miRNAs, whose expressions are induced by X-rays irradiation in HeLa cells, using a miRNA array. Here, we examined the function of miR-5094 during cellular radiation response. With software predictions and confirmatory experiments, we identified the signal transduction and activator of transcription 5b (STAT5b), a known regulator of proliferation and survival, as a target of miR-5094. The study also showed that both miR-5094 induction by X-rays irradiation and miR-5094 mimics transfection decreased STAT5b expression, down-regulated STAT5b downstream genes, and consequently, reduced the cell survival and cell viability. Knockdown of miR-5094 by miRNA inhibitor after radiation partially reversed these suppressive effects. As STAT5b plays an important role in lymphocyte proliferation, we further confirmed the proliferation inhibitory effects of miR-5094/STAT5b pathway on Jurkat cells and human peripheral blood CD4+ T cells during cell radiation response. In conclusion, our study provided the first evidence that radiation induces upregulation of miR-5094, which in turn inhibits cell proliferation via targeting STAT5b. Citation Format: Nan Ding, Junrui Hua, Jinpeng He, Wenjun Wei, Hailong Pei, Guangming Zhou, Jufang Wang, Altaf A. Wani, Qianzheng Zhu. Radiation-induced miR-5094 expression inhibits cell proliferation by targeting STAT5b [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4414.

Background B cell translocation gene 1 (BTG1) has long been recognized as a tumor suppressor gene. Recent reports demonstrated that BTG1 plays an important role in progression of cell cycle and is involved in cellular response to stressors. However, the microRNAs mediated regulatory mechanism of BTG1 expression has not been reported so far. MicroRNAs can effectively influence tumor radiosensitivity by preventing cell cycle progression, resulting in enhancement of the cytotoxicity of radiotherapy efficacy. This study aimed to demonstrating the effects of microRNAs on the BTG1 expression and cellular radiosensitivity. Methods The human renal carcinoma 786-O cells were treated with 5 Gy of X-rays. Expressions of BTG1 gene and miR-454-3p, which was predicted to target BTG1 by software algorithm, were analyzed by quantitative polymerase chain reaction. Protein expressions were assessed by Western blot. Luciferase assays were used to quantify the interaction between BTG1 3′-untranslated region (3′-UTR) and miR-454-3p. The radiosensitivity was quantified by the assay of cell viability, colony formation and caspase-3 activity. Results The expression of the BTG1 gene in 786-O cells was significantly elevated after treatments with X-ray irradiation, DMSO, or serum starvation. The up-regulation of BTG1 after irradiation reduced cellular radiosensitivity as demonstrated by the enhanced cell viability and colony formation, as well as the repressed caspase-3 activity. In comparison, knock down of BTG1 by siRNA led to significantly enhanced cellular radiosensitivity. It was found that miR-454-3p can regulate the expression of BTG1 through a direct interaction with the 3′-UTR of BTG1 mRNA. Decreasing of its expression level correlates well with BTG1 up-regulation during X-ray irradiation. Particularly, we observed that over-expression of miR-454-3p by transfection inhibited the BTG1 expression and enhanced the radiosensitivity. In addition, cell cycle analysis showed that over-expression of miR-454-3p shifted the cell cycle arrest from G2/M phase to S phase. Conclusions Our results indicate that BTG1 is a direct target of miR-454-3p. Down-regulation of BTG1 by miR-454-3p renders tumor cells sensitive to radiation. These results may shed light on the potential application in tumor radiotherapy. Electronic supplementary material The online version of this article (doi:10.1186/1748-717X-9-179) contains supplementary material, which is available to authorized users.

In order to realize the localization demand of mobile robot, the motion model and observation model of mobile robot were analyzed, and the mobile robot real-time localization algorithm of given map environment based on extended Kalman filtering was described. Besides, the algorithm was simulated. The landmark model of map was built in the process of simulation, and the landmark that was observed under control action was used to correct the location of mobile robot, by which the positioning of robot was realized. The result of simulation shows that the positional accuracy of this algorithm is very high. In addition, the construction method of real-time map of mobile robot was described on extended Kalman filtering under unknown environment based on this. Experimental result shows that this algorithm can identify the location of landmark accurately so as to give reference for the real-time positioning and mapping construction of mobile robot.

In this paper, Universal Kriging (UK) technology combined with Model Predictive Control (MPC) algorithm is exploited to estimate the unknown situation of oil dispersion for just one unmanned aerial vehicle (UAV) to predict and track the objective boundary automatically. The advantage of the Kriging method is that it is an optimal interpolator in the sense that the estimates are unbiased and the minimum variance is known, so that it can relatively accurately construct the environment map. In addition, the advantage of the MPC is its constraint handling capacity. These two uncorrelated technologies, however, can be combined to realize some special functions. The simulation based on an advection diffusion equation demonstrates the proposed method is feasible and effective.

Ionizing radiation produces reactive oxygen species (ROS), which cause damage to cells. We have synthesized a class of ROS scavengers and found that one of them, named GANRA-5, exhibits high radio-protective effects against both heavy ion irradiation and X-rays, while at the same time displaying low levels of toxicity. Pre-administration with an effective dose of GANRA-5 reduces radiation-induced damage to tissues and increases the survival rate of exposed mice. In this study, we evaluated the changes to the immune system via X-ray irradiation, and investigated how pre-administration of GANRA-5 exhibited preventative characteristics. Compared to the irradiated control groups, GANRA-5 treatment significantly reduced the radiation-induced spleen shrinkage and pathological changes. Moreover, pretreatment with GANRA-5 significantly (p < 0.01) enhanced the cellular immune response, which was characterized by higher peritoneal macrophage as well as splenocyte survival, and a higher ratio of CD4(+)/CD8(+) T lymphocytes. In addition, GANRA-5 treatment before whole body irradiation significantly improved the humoral response (p < 0.01) as indicated by the higher antibody titers of IgG, IgA, and IgM. Furthermore, GANRA-5 treatment significantly (p < 0.01) countered radiation-induced decreases in the titers of serum IL-2 and IL-4 when compared to irradiated but untreated control groups. In summary, these findings indicate that GANRA-5 provides effective protection to the immune system against X-ray-induced immunosuppression.

This paper presents a hierarchical inner-outer loop-based approach to the longitudinal and lateral control of a small unmanned helicopter in the presence of parameter uncertainties and exogenous disturbances. The outer loop employs robust H ∞ output feedback to attenuate the wind disturbance and track the reference trajectory, while the inner loop controller is proposed to solve the parameter uncertainties problems using robust H ∞ static output feedback. The obtained control method takes advantage of the feature of hierarchical structure ensuring the stability of the flight attitude. Finally, the validity of the proposed control strategy is verified through simulation results.

This paper considers the robust static output feedback control of a miniature helicopter with parameter uncertainties and wind gust disturbances. A sufficient H 2 /LMI condition is derived for suboptimal controllers of uncertain system. Then by iterative LMI algorithm, the robust static output feedback controller is designed for the helicopter system with uncertainties. In the end, simulation results are given to validate the control method.

This paper considers the environmental boundary tracking problem where the objective is to steer a mobile robot to track the desired environmental boundary. Based on the kinematic model of the mobile robot, we design a kinematic control law for the robot to track the desired boundary. Kinematic control law needs perfect velocity tracking, which doesn't always hold for a mobile robot. So, dynamic control law is designed for the nonholonomic mobile robot to track a designated reference velocity, so as to track the desired environmental boundary. The stability of the designed control laws is verified by Lyapunov theory and Barbalat's Lemma and illustrated by simulation results.

This paper examines the fault tolerant control problem for a generic class of incipient failure modes that grow in severity as a function of component loading. Assuming that a prognostic model is available to evaluate the risk of incipient fault modes growing into catastrophic failure conditions, then fundamentally the fault adaptive control problem is to adjust component loads to minimize risk of failure, while not overly degrading nominal performance. A methodology is proposed for posing this problem as a finite horizon constrained optimization, where constraints correspond to maximum risk of failure and maximum allowable deviation from nominal performance. Simulation results are given for an example system with an active redundant DC motor configuration. The fault mode simulated in this system is temperature dependent motor winding insulation degradation.

This paper attempts to make a conceptual illustration of fault prognosis-enhanced reconfiguration control. The definition of fault propagation and the proposed control adaptation algorithm ensuring the mission completion are discussed in this paper, along with some illustrative examples on prognosis-enhanced reconfiguration control of servomechanisms.

In this paper, decentralized controllers are developed to drive a swarm of mobile agents with high-order (n > 2) nonlinear dynamics in strict feedback form into a moving target region while avoiding collisions among themselves. It is important to consider coordination of multiple high-order agent dynamics which generalize the existing simple single-integrator/double-integrator ones because, in practice, we may need to incorporate actuator dynamics into the vehicle dynamics in order to achieve better performance, thus increasing the order of the system dynamics. The control design is based on a fusion of two kinds of new potential functions (target potential functions and collision avoidance potential functions), backstepping technique and Lyapunov synthesis. The presence of parametric uncertainties is handled by adaptive control techniques. The framework does not depend on a fixed ordering of agents, and is robust to individual agent failures. Therefore, flexibility and scalability are improved. Simulation results illustrate the performance of the proposed approach.

This paper addresses the boundedness of L2-L∞ norm of polytopic system with time-varying delay. Delay-dependent sufficient conditions are presented such that the L2-L∞ norm of polytopic system is less than a prescribed scalar in terms of linear matrix inequalities. Numerical example is presented.

The core of the abstraction-refinement verification is the analysis of the counterexample and refinement of the abstract model, which are the most expensive parts of the verification procedure. In this paper, we present a method that aims at reducing the complexity as much as possible. Our method combines the qualitative analysis with the reachability analysis. Qualitative analysis checks the feasibility of pair-wise transitions without the explicit numerical reachability computation. While reachability analysis employs bidirectional analysis strategy to minimize the region to be refined. Experiment shows that the integration of these strategies and techniques make the verification more efficient.

In this paper, we present an autonomous helicopter with vision based navigation called South China University of Technology unmanned aerial vehicle (SCUAV). A GPS/INS system has been designed and implemented for getting stable navigation information. A Kalman filtering has been used in this system for data fusion. A real-time computer vision system is presented in this paper as the complement of the GPS/INS system. The vision algorithm is designed and implemented in this paper, which is integrated with algorithms for tracking a known landmark and estimating the helicopter positions. A method of image processing is designed for tracking and recognizing known land marks. At the end of the paper, we will present the experiment results to demonstrate our efficacious algorithm.

In this paper the concept and model of hybrid systems are introduced. Invariant sets introduced by LaSalle is proposed, and the concept is extended to invariant sets in hybrid systems which include disturbance. It is shown that the existence of invariant sets by arbitrary transition in hybrid systems is determined by whether there exist a common Lyapunov function in the systems. Based on the Lyapunov function, an efficient transition method is proposed to ensure the existence of invariant sets. An algorithm is concluded to compute the transition mode, and the invariant set can also be computed as a convex problem. The efficiency and correctness of the transition algorithm are demonstrated by an example of hybrid systems.

A small unmanned helicopter is constructed in South China University of Technology. It has already gained some rudimental capability of autonomously flying. In this paper we introduce the further design of its multi-variable control strategy, a robust gain-scheduling algorithm. The feasibility of the proposed design is proven via simulation results.

MicroRNA (miRNA), a small non-coding RNA molecule, is vital in genetic regulation, and miRNA pathway, which regulates gene expression through degradation or translational suppression of their target transcripts, is highly conservative in evolution. Although profiles of miRNAs are different in various cell types and tissues, miRNAs have been considered as a crucial class of regulators in cellular response to ionizing radiation (IR). By carrying out a series of experiments, we have found that altered transcriptional regulation network composed of radiation-mediated miRNAs regulates the expression of their downstream target genes in most biological processes to control cell growth, cell cycle and apoptosis. For example, the newly identified miR-3928 negatively regulates the expression of Dicer, which has been validated by the luciferase assay and western blotting. Dicer is not only a key participant in responding to radiation, but also a critical factor for the maturation of miRNAs, suggesting that miR-3928 affects on the expression of other miRNAs through regulating Dicer. Among the miRNAs controlled by the Dicer, we reveal that miR-185 and miR-663 can efficiently suppress ATR and TGF-β1 expression, which are both important responders in the process of radiobiological effects. Further experiments reveal that the expression of Dicer is suppressed by miR-3928 induced by IR and consequently, the maturation of other miRNAs including miR-185 and miR-663 is inhibited, resulting in the abundantly enhanced expression of ATR and TGF-β1 respectively. This mechanism to hammer at fixing DNA damage or promote cells to apoptosis caused by IR has important implications in the decision of cell fates. Moreover, it has been shown that the expression of BTG1 is characterized in response to factors that induce growth arrest and subsequent differentiation both in vivo and in vitro, affecting cellular physiological progresses of angiogenesis, follicular development and myoblast and B cell differentiation, through regulating cell growth, migration, cell cycle, apoptosis and differentiation. BTG1 gene is phylogenetically highly conserved in its coding and 3′-untranslated region (UTR), which is considered as a decisive element involved in regulation of BTG1 expression. We present evidence that BTG1 can be induced by IR and confirm that miR-454-3p, whose gene locates in the intron of Ska2 gene, can regulate BTG1 expression through directly binding to the 3′-UTR of BTG1 mRNA. These results point out that increased expression of BTG1 caused by the down-regulation of miR-454-3p in case that IR modulates endogenous activity of PRMT1, a BTG1-binding partner, which can methylate endogenous transcription factors to change gene expression pattern and reply radiostilumation. An inverse relationship between the levels of expression of BTG1 and miR-454-3p reveals that there exists a new pathway in response to IR stimulation. Furthermore, cell growth will be transiently increased by the knockdown of BTG1 by transfecting BTG1 siRNA or miR-454-3p mimic. However, the apoptotic state of cells can be tested after 2 days. Down-regulation of BTG1 by miR-454-3p increases the sensitivity of human renal cell carcinoma 786-O cells to IR-induced apoptosis, suggesting that BTG1 could serve as a terget for sensitizing renal carcinoma to standard radiotherapy. Taken together, all these data indicate that alteration of miRNA expression is evident in the cellular response to IR. MiR-3928, miR-185, miR-663 and miR-454-3p may constitute a complex network contributing to the regulation of radiobiological effects. It is apparent that the study of radiation-related miRNAs is beneficial to qualitatively and quantitatively modulating radiobiological effects, and also in favor of the advanced research of miRNA functions.