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High temperatures (HT) before heading strongly inhibit the development of spikelets in rice. Spermidine (Spd) can improve rice’s resistance to HT stress; however, the mechanism underlying this effect has not been elucidated. This study investigated several parameters, including yield, superoxide anion (O2.-), protective enzyme activities, and polyamine content, in a heat-sensitive genotype, Shuanggui 1. The yield and yield components decreased dramatically when subjected to HT stress, while this reduction could be partially recovered by exogenous Spd. Spd also slowed the generation rate of O2.- and increased protective enzyme, superoxide dismutase (SOD) and catalase (CAT) activities both under normal and high temperatures, which suggested that Spd may participate in the antioxidant system. Furthermore, genes involved in polyamine synthesis were analyzed. The results show that HT before heading significantly increased the expression of arginine decarboxylase OsADC1, Spd synthase OsSPDS1 and OsSPDS3 and had little effect on the expression of the S-adenosylmethionine decarboxylase OsSAMDC2 and ornithine decarboxylase OsODC1. In addition, exogenous Spd considerably reduced the expression of OsSAMDC2, OsSPDS1 and OsSPDS3 under HT but not the expression of OsADC1. The above mentioned results indicate that the exogenous Spd could help young rice spikelets to resist HT stress by reducing the expression of OsSAMDC2, OsSPDS1 and OsSPDS3, resulting in higher levels of endogenous Spd and Spm, which were also positively correlated with yield. In conclusion, the adverse effect of HT stress on young spikelets seems to be alleviated by increasing the amounts of Spd and Spm, which provides guidance for adaptation to heat stress during rice production.

Alternative splicing (AS) exists in eukaryotes to increase the complexity and adaptability of systems under biophysiological conditions by increasing transcriptional and protein diversity. As a classic hormone, abscisic acid (ABA) can effectively control plant growth, improve stress resistance, and promote dormancy. At the transcriptional level, ABA helps plants respond to the outside world by regulating transcription factors through signal transduction pathways to regulate gene expression. However, at the post-transcriptional level, the mechanism by which ABA can regulate plant biological processes by mediating alternative splicing is not well understood. Therefore, this paper briefly introduces the mechanism of ABA-induced alternative splicing and the role of ABA mediating AS in plant response to the environment and its own growth.

To explore the impact of the periodic evolution in habitats on the prevention and control of the infectious disease, we consider a diffusive SIS epidemic model in a heterogeneous and periodically evolving domain. By assuming that the evolving domain is uniform and isotropic, the epidemic model in a evolving domain is converted to the reaction diffusion problem in a fixed domain. The basic reproduction number, which depends on the evolving rate of the domain and spatial heterogeneity, is defined. The driving mechanism of the model is obtained by using the principal eigenvalue and the upper and lower solutions method, and a biological explanation of the impact of regional evolution on disease is given. Our theoretical results and numerical simulations show that small evolving rate benefits the control of the infectious disease.

The sensitivity of traditional tracking control algorithm for weak disturbance signals is low and lack of flexibility. Therefore, a tracking algorithm of disturbance signals in weak power system based on observation control is proposed. Combining the characteristics of the tracking loop structure of weak disturbance signal, the tracking equation and the state control equation are designed, and the tracking control of the signals is completed. Experimental results show that the proposed algorithm simplifies the computational complexity, and has higher tracking sensitivity and accuracy.

The forests of the Tibetan Plateau store large amounts of soil organic carbon (OC) but are among the most vulnerable and sensitive ecosystems to environmental change. The lack of knowledge regarding the distribution and turnover of OC and nitrogen (N) in Tibetan Plateau forest soils limits the ability to predict how this ecosystem will respond to climate change. In this study, we collected mineral soils from coniferous and broadleaf forests on the southern Tibetan Plateau and measured OC and N contents in both bulk soils and water-stable aggregates. We also determined the mineralization of OC and N in bulk soils and examined the effects of N addition on OC mineralization. Our objectives were to investigate the distribution and mineralization of soil OC and N in various forest types and to determine the stability of OC following N addition. Our results showed that OC and N in macroaggregates contributed 76% of the OC and N in bulk soils. Forest type did not affect the OC or N contents of either bulk soils or aggregates. Similarly, OC and N mineralization and their relationships with soil OC or N contents were similar between broadleaf and coniferous forests, indicating that soil OC and N distribution and turnover were insensitive to forest type. Nitrogen mineralization was dominated by ammonification in these forest soils. Nitrogen addition did not affect OC mineralization or its relationship with soil OC or N contents. These results indicate that the OC contents of forest soils of the southern Tibetan Plateau are relatively insensitive to N addition.

To evaluate the correlation of Fast-track extubation ultrasound score (FTEUS) and clinical multi-organ information indicators in post-cardiac surgery patients.prospectively recruit post-cardiac surgery patients who were about to extubating from Febuary 2019 to September 2019. A fast-track extubation ultrasound score protocol (FTE-USP) was developed on the basis of the conventional fast-track extubation standard precisely and individualized. Cardiac, pulmonary and inferior vena cava ultrasound examinations were performed by specially trained observers, video data were saved, FTE-USP was used for scoring, Kendall consistency coefficient was used to meature the interobserver consistency. The correlation between the FTEUS and the patients' clinical indicators was evaluated.A total of 207 patients were recruited in the study, including 89 males and 118 females, aged (54.63±11.80) years. The FTEUS was performed at bedside with a mean time of (8.23±2.08) min, Kendall consistency coefficient is 0.941. With the increase of the total score of FTEUS, the incidence of clinical adverse events increased (especially the arrhythmia), and there were significant changes in liver, kidney, heart, lung and other organ function indicators, among which serum creatinine level, serum cystatin C level, serum NT-pro-brain natriuretic peptide, length of stay in intensive care unit, non-invasive mechanical ventilation time after extubation, and incidence of arrhythmia were positively correlated with FTEUS (FTE-USP integrates multi-organ informations, can be performed quickly at the bedside and alerts adverse events. It has the potential to be applied to assist clinical decision-making in post-cardiac surgery patients before extubation.

Little is known about the status of the snow leopard Panthera uncia in Qomolangma National Nature Reserve, located on the northern aspect of Mount Everest in Tibet. To address this, during May–September 2014 we conducted line transects, camera trapping, household interviews, and socioeconomic statistics analysis. We surveyed 14 transects and located 287 putative snow leopard signs, with a mean density of 1.9 sign sites km–1, 3.8 signs km–1, and 1.4 scrapes km–1. We set 41 camera traps and recorded a minimum of seven individual snow leopards. Our results were comparable to snow leopard abundance estimates for neighbouring protected areas in Nepal. Semi-structured interviews with 46 (59%) households found that local people were generally supportive of snow leopard conservation, for a variety of economic, legislative, and religious reasons. The socio-economic situation in the Reserve underwent dramatic changes between 2000 and 2014. The human population increased by 28.9%, the livestock population decreased by 9.9%, the number of tourists in 2014 was 6.8 times greater than in 2005, and the local gross domestic product underwent an annual increase of 15%. We discuss the current threats to snow leopards, and recommend that more rigorous, comprehensive, and interdisciplinary research be undertaken to provide an evidential basis for the formulation of effective conservation policies and programmes.

Purpose Because of the inconvenience and inflexibility of the laser controller, the applied range of optogenetics is limited. This paper aims to present the design of a portable remote-controlled laser controller system, including the remote-controlled system and the laser stimulator. Design/methodology/approach The remote-controlled system is handheld, which can wirelessly adjust the power and the emitting frequency of the laser by utilizing the ZigBee module. Findings The laser stimulator can be mounted on the animal as it is light weight (35 g) and small in size (40 × 40 × 20 mm), and its power and frequency can be appropriately adjusted by changing the current amplitude and duty radio. In the end, the experiments verify the reliability and effectiveness of the laser controller. Originality/value In virtue of the modular design of the driven circuit and the reasonable layout, the whole system has the advantages of small volume, convenient control and high stability, which provide the convenience for the development of portable optogenetics animal robot experiment and has broad market prospects.

Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is an important disease on wheat, seriously threatening wheat production worldwide. China is one of the largest stripe rust epidemic regions in the world. The pathogen sexual reproduction and migration routes between Tibet and the other regions in China are still unknown. In this study, we obtained 961 Pst isolates from 1,391 wheat leaf samples from Gansu (277), Shaanxi (253), Sichuan (172), and Tibet (259), comprising 13 natural populations, and genotyped them with simple sequence repeat (SSR) markers. The isolates can be divided into two distinct clusters based on DAPC and STRUCTURE analyses. The genetic diversity of Longnan (in Gansu) and Yibin (in Sichuan) populations was the highest and lowest among the 13 populations, respectively. The hypothesis of multilocus linkage disequilibrium was rejected for the populations from Linzhi in the Himalayan, Longnan, Hanzhong, Guangyuan, Mianyang, Liangshan, and Chendu in the south Qinling Mountains at the level of P = 0.01, which indicated significant linkage among markers in these populations. Populations in the other regions had extensive gene exchange (Nm > 4); little gene exchange was found between Tibet and the other regions (Nm < 1). The results suggest that the Tibet epidemic region of Pst is highly differentiated from the other epidemic regions in China.

Background Little information is available regarding the knowledge, attitudes and practices (KAP) of the owners of yaks in Tibet with respect to brucellosis. Methods This manuscript reports on the results of a cross-sectional survey using a structured questionnaire investigating the KAP of 317 yak herders from 34 villages in the three main yak-rearing counties of Maizhokunggar, Damxung and Yadong from April to August 2015. Results Although 60.6% of the respondents had heard of brucellosis, there was an overall low level of knowledge about the disease. Herders did, however, adopt management/husbandry practices which would reduce transmission of the disease to humans and other animals. Multivariable logistic modelling showed that a better knowledge was predicted by age, production system adopted, education level and number of people in a household. Differences in attitudes and practices were predicted by education level, production system and household size. Conclusions In order to increase the awareness of herders on brucellosis and to reduce the risk of infection in both humans and other animals, public health education campaigns should be developed and offered to livestock owners in Tibet.

This paper studies designing resilient asynchronous H ∞ state feedback controller for Markov jump systems with transition probabilities partly unknown. By Finsler's Lemma, and with the help of three matrices with special structure, the problem of inter connection between the Lyapunov matrices and the system matrices is solved. In order to make the theory have more practical value, this paper considers the transition probabilities as partly unknown. The controller designed in this paper improves the robustness of the systems and is able to work when the jump between the system modes and the controller modes is asynchronous, meanwhile makes sure the system has a prescribed H ∞ performance index but also is stochastically stable.

An improved method based on the D-H method is proposed for a 5-DOF manipulator with special structure which is difficult to establish joint transformation by using normal D-H method. The forward kinematics of this manipulator with special structure is established by adding virtual joint. The method is suitable for manipulators with rotating joints, and the coordinate transformation must be achieved by transform along the Z axis. The process of inverse kinematics of the manipulator is analyzed. The conditions for the existence of inverse solution and the number of inverse solutions are also analyzed. Finally, the simulation of the proposed scheme is carried out to verify its correctness. And it has been applied to the physical mechanical arm.

This paper investigates three-party password authenticated key exchange protocols using elliptic curve cryptosystem (ECC). We first show that the direct elliptic curve analog of Chien’s protocol proposed most recently is vulnerable to off-line dictionary attack. Thereafter, we present an enhanced protocol based on ECC. Our proposal can defeat password-guessing attacks and the stolen-verifier attacks. And yet, it is also efficient. Furthermore, we can provide the rigorous proof of the security for it. Therefore, the protocol is quite popular in low resource environments.

Phenolic compounds, the most abundant secondary metabolites in plants, have received more and more attention in recent years because of their distinct bioactivities. This review summarizes different types of phenolic compounds and their extraction and analytical methods used in the recent reports, involving 59 phenolic compounds from 52 kinds of plants. The extraction methods include solid-liquid extraction, ultrasound-assisted extractions, microwave-assisted extractions, supercritical fluid extraction, and other methods. The analysis methods include spectrophotometry, gas chromatography, liquid chromatography, thin-layer chromatography, capillary electrophoresis, and near-infrared spectroscopy. After illustrating the specific conditions of the analytical methods, the advantages and disadvantages of each method are also summarized, pointing out their respective suitability. This review provides valuable reference for identification and/or quantification of phenolic compounds from natural products.

This paper is to study the linear minimum variance estimation for discrete-time singular WSN systems with multiplicative noises and additive noises. The state and the state disturbed by multiplicative noise are both included in the observation equation. A simple approach of projection theorem is proposed.

To broadcast a message secretly and consistently to the receivers in the broadcasting networks, Jeong et al. suggested an efficient secret broadcast scheme using binding encryption quite recently. In this letter, we first show that their scheme just achieves consistency in a relatively weak security model but not in a stronger model. Furthermore, we point out their scheme is not so efficient even when their model is accepted. Thereafter, we suggest a simple and more efficient scheme, which can be proved in their model without using random oracles.

To overcome the congenital defects of the UMTS's Authentication and Key Agreement (AKA) protocol standard, Ou et al. proposed an improved protocol called the cocktail-AKA protocol recently. In this paper, we first show that it has some security weaknesses, which can be exploited by an adversary to mount a denial of service attack and an impersonation attack. Finally, an effective countermeasure is suggested.

In order to obtain the optimal conditions for separating the alkaloids from the extract of Stemona japonica by selecting appropriate cation exchange resins.Seven types of cation exchange resins were evaluated in separating efficiency with measuring the adsorption ratio and eluting ratio of total alkaloids as indices, and the content of total alkaloids from Stemona japonica was determined as an index by spectrophotometry to choose the optimal technological parameters.The optimal result of extraction was obtained as Stemona japonica shattered into thick powder, adding eight times amount of 90% alcohol and refluxing and extracting for 3 h (totally extracting for 3 times). Each gram of D004 cation exchange resin could absorb 0.5003 mg of the total alkaloid, and the desorption ratio was 68.45%. The transfer rate of total alkaloids was 58.70%. the product purity of alkaloids was up to 70%.The D004 cation exchange resin can be used for purificating total alkaloids from Stemona japonica and the established procedure is simple and feasible.

To optimize the process for purification of geniposide in the extract fluid of Gardenia jasminoides with macroporous absorption resin.By comparing the content and transfer ratio of geniposide during the process of purification, we optimized the process for purification of geniposide.The optimal process for purification of geniposide with D301R macroporous absorption resin included the diameter height ratio 1:7.5, the concentration of the extract fluid of Gardenia jasminoides 2:1, the flow rate 1BV/h (1BV represented one column volume), the sample volume 1/3BV. We loaded the sample and left it for 2 hours, afterwards, rinsed the macroporous absorption resin using 2BV water until the solution became colourless. Then we rinsed the macroporous absorption resin with 20% alcohol,and the volume of elution solvent was 2BV. We collected 20% alcohol elution solvent and recycle alcohol using rotating evaporation and dried the rest solution in a vacuum to get the light yellow powder which was the purified geniposide.This process is simple and affordable, can be used to refine and purify geniposide in the extract fluid of Gardenia jasminoides Ellis. It provides a guidance for industrial production basis.

The paper is concerned with Kalman filtering for wireless sensor network (WSN) with multiple multiplicative noises. Two measurements which are received through two different channels are considered in this system, and some packets are lost independently. Kalman filter for the above system is presented by solving a Lyapunov equation and a Riccati equation. Moreover, the optimal filter for the case of the system with multiple multiplicative noises is also presented. Furthermore, some results for the Lyapunov equation and the Riccati equation are proposed to analyze the performances of the Kalman filters.

The paper deals with the Kalman filtering problem for a linear discrete-time system with both instantaneous and time-delayed measurements, where the delayed measurements are from multipath or multi-channel. Different from the standard system, multipath delayed measurements are introduced in the state-space. Projection formulation and reorganized innovation analysis are used to deal with such a problem. The solution to the derived Kalman filter is given in terms of Riccati difference equations.

Most recently, Yang et al proposed a new set of security requirements for two-factor smart-card-based password mutual authentication and then suggested a new scheme satisfying all their security requirements. In this paper, however, we first show one critical security weakness being overlooked, i.e., allowing key-compromise impersonation. We provide an attack to illustrate the adversary is able to masquerade any user to access the server's service in their protocol once if the long-term key of the server is compromised. Thereafter, we suggests key-compromise impersonation resilience should be added as one more important security requirement for two-factor smart-card based password mutual authentication and then propose an improved protocol to eliminate the security weakness existing in Yang et al's protocol.

Recently, Lu et al. presented an enhanced authenticated key agreement protocol based on elliptic curves cryptography and included their protocol in 3GPP2 specifications to improve the security of A-Key distribution. In this paper, we first show the proposed protocol can’t resist the offline password guessing attack, and then present an enhanced protocol to remedy the security loopholes. On the other hand, through this work, we also hope to contribute towards a better understanding of the importance and necessity of including the key derivation step in key agreement protocols.

Most recently, Chang et al proposed an authentication scheme with anonymity for roaming service in global mobility networks. Unfortunately, the scheme was still found insecure by Youn et al. However, they did not present any countermeasures to fix its security weaknesses. In this paper, we propose such an enhanced scheme that can remedy the security loopholes existing in Chang et al’s scheme while the merits of the original scheme are left unchanged. In addition, we consider a lot from practical aspects in our scheme. Therefore, the end result is a secure and efficient user authentication scheme well-suited to roaming service in global mobility networks.

Quite recently, Yang et al. presented an efficient three-party authenticated key exchange protocol based upon elliptic curve cryptography for mobile-commerce environments. In this paper, we demonstrate that Yang et al's three-party authenticated protocol is potentially vulnerable to an unknown key-share attack. Thereafter, we suggest a countermeasure to resist our described attacks while the merits of the original protocol are left unchanged. On the other hand, through this work, we also highlight that the existence of insider attacks needs to be taken into consideration in the three-party setting.

Quite recently, Li et al's suggested an efficient verifier-based password-authentication key exchange protocol via elliptic curves. In this paper, we shows that their protocol is still vulnerable to off-line dictionary attack and unknown key-share attack. Through our work, we hope the similar mistakes can be avoided in future designs.