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AbstractThis paper provides a review of cyber risk research accomplished in different disciplines, with a primary goal to aid researchers in the field of insurance and actuarial science in identifying potential research gaps as well as leveraging useful models and techniques that have been considered in the literature. We highlight the recent advancements in cyber risk prediction, modeling, management, and insurance achieved in different domains including computer engineering, actuarial science, and business studies. The surveyed works are classified according to their respective modeling approaches, allowing readers to more easily compare the technical aspects of the surveyed works and spot out research gaps based on the research tools of their liking. We conclude this paper with a summary of possible research directions that are identified from the review.

AbstractWith the recent outbreak of COVID-19, evaluating the epidemic risk appears to be a pressing issue of global concern and one of the major challenges recently. In the fight against pandemics, the ability to understand, model, and forecast the transmission dynamics of infectious diseases plays a crucial role. This paper provides an overview of foundational compartment models and introduces the Susceptible-Exposed-Infected-Containing-3-Substates-Recovered-Dead model to study the dynamics of COVID-19. A meticulous data calibration procedure is employed to study the evolution trend of an actual pandemic using real-world data from Victoria, Australia. Additionally, the paper discusses innovative applications of epidemic models to the insurance industry, which are currently under investigation. Through the use of the newly developed analytically tractable model, insurance companies are able to determine fair premium levels during an outbreak. Moreover, the paper provides practical guidance for insurance companies by examining the variation in reserve levels over time.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with progressive loss of motor neurons in the spinal cord, cerebral cortex and brain stem. ALS is characterized by gradual muscle atrophy and dyskinesia. The limited knowledge on the pathology of ALS has impeded the development of therapeutics for the disease. Previous studies have shown that autophagy and astrocyte-mediated neuroinflammation are involved in the pathogenesis of ALS, while 5HTR2Aparticipates in the early stage of astrocyte activation, and 5HTR2Aantagonism may suppress astrocyte activation. In this study, we evaluated the therapeutic effects of desloratadine (DLT), a selective 5HTR2Aantagonist, in human SOD1G93A(hSOD1G93A) ALS model mice, and elucidated the underlying mechanisms. HSOD1G93Amice were administered DLT (20 mg·kg−1·d−1, i.g.) from the age of 8 weeks for 10 weeks or until death. ALS onset time and lifespan were determined using rotarod and righting reflex tests, respectively. We found that astrocyte activation accompanying with serotonin receptor 2 A (5HTR2A) upregulation in the spinal cord was tightly associated with ALS-like pathology, which was effectively attenuated by DLT administration. We showed that DLT administration significantly delayed ALS symptom onset time, prolonged lifespan and ameliorated movement disorders, gastrocnemius injury and spinal motor neuronal loss in hSOD1G93Amice. Spinal cord-specific knockdown of 5HTR2Aby intrathecal injection of adeno-associated virus9 (AAV9)-si-5Htr2aalso ameliorated ALS pathology in hSOD1G93Amice, and occluded the therapeutic effects of DLT administration. Furthermore, we demonstrated that DLT administration promoted autophagy to reduce mutant hSOD1 levels through 5HTR2A/cAMP/AMPK pathway, suppressed oxidative stress through 5HTR2A/cAMP/AMPK/Nrf2-HO-1/NQO-1 pathway, and inhibited astrocyte neuroinflammation through 5HTR2A/cAMP/AMPK/NF-κB/NLRP3 pathway in the spinal cord of hSOD1G93Amice. In summary, 5HTR2Aantagonism shows promise as a therapeutic strategy for ALS, highlighting the potential of DLT in the treatment of the disease.

Heterodera filipjevicontinues to be a major threat to wheat production worldwide. Rapid detection and quantification of cyst nematodes are essential for more effective control against this nematode disease. In the present study, a TaqMan-minor groove binder (TaqMan-MGB) probe-based fluorescence quantitative real-time PCR (qPCR) was successfully developed and used for quantifying H. filipjevifrom DNA extracts of soil. The primers and probe designed from the obtained RAPD-SCAR marker fragments of H. filipjevishowed high specificity to H. filipjeviusing DNA from isolates-confirmed species of 23 Heteroderaspp., 1 Globoderaspp. and 3 Pratylenchusspp. The qPCR assay is highly sensitive and provides improved H. filipjevidetection sensitivity of as low as 4–3single second-stage juvenile (J2) DNAs, 10–3female DNAs, and 0.01 μg μL–1genomic DNAs. A standard curve relating to the threshold cycle and log values of nematode numbers was generated and validated from artificially infested soils and was used to quantify H. filipjeviin naturally infested field soils. There was a high correlation between the H. filipjevinumbers estimated from 32 naturally infested field soils by both conventional methods and the numbers quantified using the qPCR assay. qPCR potentially provides a useful platform for the efficient detection and quantification of H. filipjevidirectly from field soils and to quantify this species directly from DNA extracts of field soils.

ABSTRACTPancreatic cancer (PC) is one of the most fatal cancers with a very poor prognosis. Here, we found that N6-methyladenosine (m6A) RNA demethylase fat mass and obesity-related protein (FTO) promote the growth, migration and invasion of PC. FTO expression level is increased in human PC and is associated with poor prognosis of PC patients. Knockdown of FTO increases m6A methylation of TFPI-2 mRNA in PC cells, thereby increasing mRNA stability via the m6A reader YTHDF1, resulting in up-regulation of TFPI-2 expression, and inhibits PC proliferation, colony formation, sphere formation, migration and invasion in vitro, as well as tumour growth in vivo. Rescue assay further confirms that FTO facilitates cancer progression by reducing the expression of TFPI-2. Mechanistically, FTO promotes the progression of PC at least partially through reducing m6A/YTHDF1 mediated TFPI-2 mRNA stability. Our findings reveal that FTO, as an m6A demethylase, plays a critical role in promoting PC growth, migration and invasion, suggesting that FTO may be a potential therapeutic target for treating PC.

Soybean cyst nematode (SCN) Heterodera glycinesis considered as the major constraint to soybean production. GmSHMT08at Rhg4locus on chromosome 08, encoding a serine hydroxylmethyltransferase, is a major gene underlying resistance against H. glycinesin Peking-type soybeans. However, the molecular mechanism underpinning this resistance is less well characterized, and whether GmSHMT08 could interact with proteins in H. glycinesremains unclear. In this study, yeast two-hybrid screening was conducted using GmSHMT08 as a bait protein, and a fragment of a 70-kDa heat shock protein (HgHSP70) was screened from H. glycinesthat exhibited interaction with GmSHMT08. This interaction was verified by both GST pull-down and bimolecular fluorescence complementation assays. Our finding reveals HgHSP70could be applied as a potential candidate gene for further exploring the mechanism on GmSHMT08-mediated resistance against SCN H. glycines.

Potassium (K), an important nutrient element, can improve the stress resistance/tolerance of crops. The application of K in resisting plant-parasitic nematodes shows that the K treatment can reduce the occurrence of nematode diseases and increase crop yield. However, data on K2SO4induced rice resistance against the root-knot nematode Meloidogynegraminicolaare still lacking. In this work, K2SO4treatment reduced galls and nematodes in rice plants and delayed the development of nematodes. Rather than affecting the attractiveness of roots to nematodes and the morphological phenotype of giant cells at feeding sites, such an effect is achieved by rapidly priming hydrogen peroxide (H2O2) accumulation and increasing callose deposition. Meanwhile, galls and nematodes in rice roots were more in the potassium channel OsAKT1 and transporter OsHAK5 gene-deficient plants than in wild-type, while the K2SO4-induced resistance showed weaker in the defective plants. In addition, during the process of nematode infection, the expression of jasmonic acid (JA)/ethylene (ET)/brassinolide (BR) signaling pathway-related genes and pathogenesis-related (PR) genes OsPR1a/OsPR1bwas up-regulated in rice after K2SO4treatment. In conclusion, K2SO4induced rice resistance against M. graminicola. The mechanism of inducing resistance was to prime the basal defense and required the participation of the K+channel and transporter in rice. These laid a foundation for further study on the mechanism of rice defense against nematodes and the rational use of potassium fertilizer on improving rice resistance against nematodes in the field.

Intrauterine hypoxia (IUH) affects the growth and development of offspring. It remains unclear that how long the impact of IUH on cognitive function lasts and whether sexual differences exist. Spermidine (SPD) has shown to improve cognition, but its effect on the cognitive function of IUH offspring remains unknown. In the present study we investigated the influence of IUH on body weight and neurological, motor and cognitive function and the expression of APP, BACE1 and Tau5 proteins in brain tissues in 2- and 4-month-old IUH rat offspring, as well as the effects of SPD intervention on these parameters. IUH rat model was established by treating pregnant rats with intermittent hypoxia on gestational days 15–21, meanwhile pregnant rats were administered SPD (5 mg·kg−1·d−1;ip) for 7 days. Neurological deficits were assessed in the Longa scoring test; motor and cognitive functions were evaluated in coat hanger test and active avoidance test, respectively. We found that IUH decreased the body weight of rats in both sexes but merely impaired motor and cognitive function in female rats without changing neurological function in the rat offspring of either sex at 2 months of age. For 4-month-old offspring, IUH decreased body weight in males and impaired neurological function and increased cognitive function in both sexes. IUH did not affect APP, BACE1 or Tau5 protein expression in either the hippocampus or cortex of all offspring; however, it increased the cortical Tau5 level in 2-month-old female offspring. Surprisingly, SPD intervention prevented weight loss. SPD intervention reversed the motor and cognitive decline caused by IUH in 2-month-old female rat offspring. Taken together, IUH-induced cognitive decline in rat offspring is sex-dependent during puberty and can be recovered in adult rats. SPD intervention improves IUH-induced cognitive and neural function decline.

This work develops an approximation procedure for a class of non-zero-sum stochastic differential investment and reinsurance games between two insurance companies. Both proportional reinsurance and excess-of loss reinsurance policies are considered. We develop numerical algorithms to obtain the approximation to the Nash equilibrium by adopting the Markov chain approximation methodology. We establish the convergence of the approximation sequences and the approximation to the value functions. Numerical examples are presented to illustrate the applicability of the algorithms.

This paper develops an optimal dividend policy for an insurance company, whose asset and liability have different dynamics, and whose surplus follows a regime-switching jump–diffusion process. The insurer aims to maximize the expected total discounted value of dividends paid out under the debt management constraint. By using the dynamic programming principle, a generalized system of integro-differential Hamilton–Jacobi–Bellman equations is derived. Moreover, this paper studies two cases where the liability of the insurer follows a uniform claim density and a generalized Pareto density in a two-regime economy, respectively. Closed-form solutions of the value functions and the optimal dividend payment strategies are obtained in both cases. A numerical example is provided to illustrate the relationship between the key parameters in the model and the value functions, as well as some interesting economic insights.

This paper provides a survey on several numerical approximation schemes for stochastic control problems that arise from actuarial science and finance. The problems to be considered include dividend optimization, reinsurance game, and quantile hedging for guaranteed minimum death benefits. To better describe the complicated financial markets and their inherent uncertainty and randomness, the so-called regime-switching models are adopted. Such models are more realistic and versatile, however, far more complicated to handle. Due to the complexity of the construction, the regime-switching diffusion systems can only be solved in very special cases. In general, it is virtually impossible to obtain closed-form solutions. We use Markov chain approximation techniques to construct discrete-time controlled Markov chains to approximate the value function and optimal controls. Examples are presented to illustrate the applicability of the numerical methods.

This work develops a new model to deal with the scenario that some companies can still run business even the surplus falls below zero temporarily. With such a scenario in mind, we allow the surplus process to continue in this negative-surplus period, during which capital injections will be ordered to assist in the stabilization of financial structure, until the financial status becomes severe enough to file bankruptcy. The capital injections will be modeled as impulse controls. By introducing the capital injections with time delays, optimal dividend payment and capital injection policies are considered. Using the dynamic programming approach, the value function obeys a quasi-variational inequality. With delays in capital injections, the company will be exposed to the risk of bankruptcy during the delay period. In addition, the optimal dividend payment and capital injection strategies should balance the expected cost of the possible capital injections and the time value of the delay periods. This gives rise to a stochastic control problem with mixed singular and delayed impulse controls. Under general assumptions, the lower capital injection barrier is determined, where bankruptcy occurs. The closed-form solution to the value function and corresponding optimal policies are obtained.

Based on the characteristics of weather modification in Yunnan Province, this paper proposed a weather modification operation model which aims to help operating managers with operating scenario and provide operating spots, fixed or mobile, with detailed intelligent decision-making information, including: operating spot, fire elevation, azimuth, amount of ammunition. The data that this model utilizes is from the conventional sounding materials, XDR radar and DPL radar together with the historical applications and actual usage.

The elm wood samples were tested by the technique of ultrasonic, and the testing results were analyzed by using the statistic software of SPSS. The results showed that the moister content of wood, wood crack, the sizes of holes and numbers of holes have significant influence on propagation parameters and dynamic modulus of elasticity. If there are holes or cracks in the propagation path, the propagation time will be longer, and the propagation velocity and wood modulus will decrease accordingly. The studying results of this paper will provide a sound background for the application of ultrasonic technique in detecting the inner defects of wood products and other wooden structures, and also offer important reference for testing the inner defects of old trees and ancient buildings.

The elm wood samples were tested by the technique of stress wave, and the testing results were analyzed by using the statistic software of SPSS. The results showed that the moister content of wood, wood crack, the sizes of holes and numbers of holes have significant influence on propagation parameters and dynamic modulus of elasticity. Under the same specifications, the propagation time of the stress wave was longer in the wood with holes or cracks than the perfect wood samples, and the time become longer with the increasing the sizes and numbers of holes or cracks. The studying results of the thesis will provide a sound background for the application of stress-wave technique in detecting the inner defects of wood products and other wooden structures.

A mathematical model was developed to assess the economic feasibility of a biomass-based power plant in the Northeast of China. The objective of this model is to maximizes the net present value (NPV) of a biopower plant over its economic life, which subjects to the constraints of biomass availability, plant investment and operation & maintenance costs, plant capacity, transportation logistics, raw material and product pricing, financing, and business taxes. The model was applied in a biopower plant located in Wangkui County, China, which belongs to the National Bio-Energy Group Company Limited. Results showed that the maximum NPV of the Wangkui Biopower plant in the base case was approximately 117 million Yuan given the electricity sale price of 0.64 Yuan kWh-1 (or 0.75Yuan kWh-1 with tax). This study provides a reference for evaluating the economic feasibility of biopower plants based on biomass logistics networks in China.

The operation of many biomass-based power plants in China have demonstrated that biomass supply logistics system is a key part to achieve economic, stable, and safe operation for such plants. In this paper, the straw biomass supply system of a biomass-based power plant located in Wangkui County, Heilongjiang Province was analyzed, and a mathematical model was established to optimize the fuel supply system. In consideration of the current straw biomass fuel supply system in China, that is "fuel origin – purchasing station - power plant", appropriate hypothesis and simplification were made on the linear transportation model. The logistics parameters for the biopower plant were obtained through the model analysis. Sensitivity analyses were conducted to analyze the optimal delivered cost of biomass under different operation scenarios, which enhanced the reliability of the final results. The optimal model proposed in this paper can also be used as a reference for the other biopower plants in the other regions.

The current status of broiler production in one of the subsidiary companies in Heilongjiang Chia Tai Group was investigated. Based on the summarization and analysis on its production flow and production layout, some layout symbols were put forward. These symbols can bring more convenience if used together with production flow chart in the planning and design of production logistics.

While cloud computing related technologies are gaining increasing amount of popularities nowadays, we are focusing our resent research on the aspects of software evolution processes under the environments of cloud computing. During our pervious research, we have proposed SEPUCCC, a software evolution process prototype under the circumstancees of cloud computing. In this article, we are going to have a further disscussion on SEPUCCC by giving it’s in-depth performance analysis, by which the model’s abilities, the abilities to supporting the evolution process under the circumstances of cloud computing as well as reducing the cost of process improvemnet, was demomstrated.

Abstract: Interest in inverse reinforcement learning (IRL) has recently increased, that is, interest in the problem of recovering the reward function underlying a Markov decision process (MDP) given the dynamics of the system and the behavior of an expert. This paper deals with an incremental approach to online IRL. First, the convergence property of the incremental method for the IRL problem was investigated, and the bounds of both the mistake number during the learning process and regret were provided by using a detailed proof. Then an online algorithm based on incremental error correcting was derived to deal with the IRL problem. The key idea is to add an increment to the current reward estimate each time an action mismatch occurs. This leads to an estimate that approaches a target optimal value. The proposed method was tested in a driving simulation experiment and found to be able to efficiently recover an adequate reward function.

Abstract: We improve inverse reinforcement learning (IRL) by applying dimension reduction methods to automatically extract abstract features from human-demonstrated policies, to deal with the cases where features are either unknown or numerous. The importance rating of each abstract feature is incorporated into the reward function. Simulation is performed on a task of driving in a five-lane highway, where the controlled car has the largest fixed speed among all the cars. Performance is almost 10.6% better on average with than without importance ratings.

The development of polymers that are viable for chemical recycling to monomers is highly significant in terms of both environmental issues and resource reuse. Sulfur-rich polymers that possess several enhanced features, such as good refractive index and thermal and mechanical properties, are conventionally non-recyclable. Herein, we present a strategy for obtaining a recyclable polytrithiocarbonate, a typical category of sulfur-rich polymers, via organic base-mediated ring-opening polymerization of seven-membered cyclic trithiocarbonate (δ-CTC). The resulting polytrithiocarbonates exhibit good thermal, mechanical, and optical properties, which are superior to their analogue polycarbonate. Notably, the polytrithiocarbonates can return to the starting δ-CTC monomers via a simple pyrolysis. The recycled monomers can be transformed into the polymers in high efficiency as the starting monomers. Moreover, this method is applicable for tuning the structure of recyclable polytrithiocarbonates by copolymerizing δ-CTC with α-position methyl-substituted δ-CTC, thus realizing the adjustment of the properties of the polytrithiocarbonate.

Six somatic embryogenesis-associated cDNAs (PgEMB2, 6, 7, 8, 24 and 34) from white spruce (Picea glauca (Moench) Voss) somatic embryos have been characterized. Transcript accumulation during somatic embryo development and subsequent germination related to these genes, indicated that they were developmentally regulated. The transcripts related to clones PgEMB2, 6, 24 and 34 were also detected during zygotic embryo development, but transcripts of clones PgEMB7 and 8 were not. PgEMB24 had a similar gene expression pattern to spruce Em-like late embryo abundant (lea) gene, but other clones had no similarities in gene expression to either spruce lea-like or storage protein genes. Abscisic acid, a stimulator for spruce somatic embryo maturation, did not obviously affect gene expression corresponding to these cDNAs. The predicted proteins are distinguishable from known LEA proteins based on analyses of hydropathy plots, amino acid compositions and deduced protein structures. The similarities of the spruce cDNAs, and protein sequences predicted from these cDNAs, to other sequence data are described.

Abstract.: Five abscisic acid (ABA)-responsive cDNAs that were identified by differential screening of a white spruce [Picea glauca (Moench) Voss] cotyledonary somatic embryo cDNA library are characterized. Three of the cDNAs (PgEMB12, 14, 15) are predicted to encode homologues of different late-embryogenesis-abundant (LEA) proteins, a further two (PgEMB 5 and 23) share little similarity to any known DNA or protein sequences. When suspension cultures were fed 1.5 × 105 M S-(+)-ABA and assessed for transcript abundance over 48 h, gene expression corresponding to each lea-like gene was inducible and was evident during the 48-h period. Conversely, transcripts were at a very low abundance when suspensions were fed R-(−)-ABA. When suspensions were treated with a range of S-(+)-ABA and R-(−)-ABA concentrations (10−7–10−4 M), expression was induced at S-(+)-ABA concentrations of 10−5 M or above. Expression corresponding to PgEMB5 and PgEMB23 indicates less specificity for ABA stereostructure, with similar expression patterns being observed for either enantiomer during the 48 h after feeding. The two corresponding genes also appear more responsive to ABA concentration than the predicted lea genes, within the range examined (10−7–10−4 M).

We have established a regeneration protocol for melon (Cucumis melo L.), using cotyledons as explants, in which the overall regeneration frequency reached more than 90 percent, and combined this protocol with Agrobacterium tumefaciens transformation to produce transgenic melon plants. Cotyledon explants were coculti-vated with A. tumefaciens carrying a disarmed Ti plasmid in which a dihydrofo-late reductase (DHFR) coding sequence and a β-glucuronidase (GUS) coding sequence were separately fused to the Cauliflower Mosaic Virus (CaMV) 35S promoter. A second strain carried a plasmid in which the neomycin phosphotransfer-ase II (NPTII) and GUS coding sequences were fused to a bidirectional CaMV 35S promoter. Under optimal conditions, the highest transformation frequency was approximately 6 percent. The transgenic melon plants were normal in morphology and fertile. Segregation analysis of R1 seedlings showed that the transgenes were inherited in a Mendelian manner. The CaMV 35S promoter was found to be active in most but not all tissues of transgenic melon plants, and the expression pattern conferred by the promoter changed during plant development.

Abscisic acid (ABA) is involved in various physiological processes in plant growth and in the development of embryos and the maturation of seed. There is still much to learn about the influence of ABA on regulation of gene expression during plant and seed development. Perhaps not surprisingly, ABA has a major role in the stimulation of somatic embryo maturation in several conifer species, especially spruces. In spite of this, our knowledge of the effects of exogenous ABA is incomplete, for example the effect of ABA concentration on its uptake and fate has rarely been investigated during somatic embryo culture, and our knowledge of molecular events in conifer somatic embryo development is very scant. The intent of this review is to summarize some of the recent research in spruce somatic embryo development related to the use of ABA and to the consequence of its use.

Three cDNAs (PgEMB22, 27 and 29) predicted to encode low-molecular-weight (LMW) heat-shock proteins (HSPs) were cloned and characterized from white spruce [Picea glauca (Moench) Voss] somatic embryo tissues by differentially screening a cotyledonary embryo cDNA library. Clone PgEMB22 is predicted to encode a putative mitochondria-localized LMW HSP, and PgEMB27 and 29 are predicted to encode different cytoplasmic class II LMW HSPs, although they share 84.7% identity within DNA coding regions and 83.0% identity for predicted proteins. They are developmentally regulated during somatic embryo development and subsequent embryo germination, in addition they show strong response to heat-shock stress. Transcripts of the two kinds of hsp genes could be detected in embryogenic tissues before induction of embryo maturation, but subsequently increased, being most abundant at late embryo stages. Gene expression levels were very low or not detectable in germinated plantlets or needle tissues from older plants. Abscisic acid and polyethylene glycol, stimulators for spruce embryo maturation, could also induce the hsp genes.

Embryogenic tissues of white spruce [Picea glauca (Moench) Voss] remain in an early developmental stage while cultured on 2,4-dichlorophenoxyacetic acid and N6-benzyladenine, but develop to cotyledonary embryos when these phytohormones are replaced by abscisic acid. Twenty-eight cDNAs were isolated from cotyledonary embryos by differential screening against immature embryo and non-embryonic tissues. Temporal expression patterns of these cDNAs during ABA-stimulated somatic embryo development were observed. This showed that clones could be allocated to various groups, including embryo-abundant, embryo-maturation-induced, and those whose expression was modulated during embryo development, germination or in non-embryogenic tissues. Expression corresponding to these cDNA clones showed that there were various responses to exogenous ABA or polyethylene glycol during a period of 48 h. Analyses of DNA and predicted amino acid sequence revealed that 12 of 28 cDNA clones had no known homologues, while others were predicted to encode different late-embryogenesis-abundant proteins, early methionine-labelled proteins, storage proteins, heat-shock proteins, glycine-rich cell wall protein, metallothionein-like protein and some other metabolic enzymes.

Cellular transformation intensities on flax (Linum usitatissimum) hypocotyl explants using disarmed Agrobacterium tumefaciens were investigated through various preculture durations, cocultivation durations and removal of epidermis. The expression of an intron-containing ß-glucuronidase (GUS) gene driven by CaMV 35S promoter served as a reporter for determination of transformed tissues on hypocotyls. The binary plasmid p35SGUSINT in octopine-type Agrobacterium strain GV2260 was used as the vector system. A prolonged cocultivation duration (5–7 days) resulted in a much higher transformation staining intensity (frequency * tissue area) than 2- or 3-day-cocultivation duration on hypocotyls variously precultured prior to inoculation. A high staining intensity on the two cut ends was obtained from nonprecultured hypocotyls. A reduction in intensity on the upper cut end of hypocotyls was observed with preculture times greater than 6 days. Peeled hypocotyls with a post-peeling preculture of 2 or 3 days had a high proportion of superficial area covered by transformed tissues after a 7 day-cocultivation duration. These results will help to improve the efficiency of recovery of transgenic plants by increasing the proportion of transformation in the regenerable tissues.

A simple and efficient procedure suitable for extraction of high-quality RNA from cultured conifer tissues, somatic embryos, zygotic embryos, needles, stem and root tissues was developed. It produced from 100 µg up to 700 µg total RNA per gram tissue dependent on the types of tissues used. RNA quality was estimated by spectrophotometry, agarose gel electrophoresis, in vitro translation of mRNA, cDNA synthesis and Northern blot analysis. The method also worked well with Arabidopsis thaliana and tobacco tissues.

Cotyledons of various ages from seedlings of eight watermelon (Citrullus vulgaris) cultivars were cultured on MS medium supplemented with different combinations of phytohormones. High frequency shoot regeneration (60.0–92.0%) was induced from 5-day-old cotyledons of cultivars cultured on MS medium containing 5.0 mg/l 6-benzylaminopurine (BA) and 0.5 mg/l indole-3-acetic acid (IAA). Multiple shoot buds elongated on MS medium containing 0.2 mg/l kinetin (KT) and 5–10 shoots per expiant could be recovered depending on the cultivars. Elongated shoots rooted on MS medium with 0.1 mg/l a-naphthalene acetic acid (NAA). Zeatin riboside (ZT) had a similar efficiency as BA in shoot induction, and it was significantly more functional than 2-isopentenyladenine (2iP) or kinetin (KT). Cotyledons from 5-day-old seedlings were the most responsive to shoot induction.

The extract of Penthorum chinensePursh (PCP), a well-known Miao herb medicine, has been used as a key component for a Chinese patented drug to treat several kinds of liver-related diseases. In this work, 3 pinocembrin derivatives, S1, S2, and S3, were isolated from PCP stems and identified with high-performance liquid chromatography and electrospray ionization mass spectrometer. The molecular masses of S1, S2, and S3 were identical to Pinocembrin-7-O-[4″,6″-hexahydroxydiphenoyl (HHDP)]-β-D-glucose, Pinocembrin-7-O-[3″-O-galloyl-4″,6″-(s)-HHDP)-β-D-glucose, and Thonningianin A, respectively. Their free radical scavenging capability was evaluated with the 2,2-diphenyl-1-picrylhydrazyl assay. The half-maximal effective concentrations of S1, S2, and S3 were 26.75, 9.06, and 5.50 μg/mL, respectively. In vitro AML-12 assays demonstrated that S1 (5-20 μg/mL), S2 (10-40 μg/mL), and S3 (10-40 μg/mL) not only protected cells from H2O2-induced oxidation and alcohol-induced cell damages, but also reduced oleic acid (OA)-induced triglyceride accumulations in a dose-dependent manner. However, the 3 compounds potently exhibited similar cytotoxicity effect at high concentrations. The half-maximal inhibitory concentrations of S1, S2, and S3 to AML-12 cells were 74.19, 85.86, and 80.43 μg/mL. In addition, the 3 compounds also showed antibacterial activity on Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, Lactobacillus rhamnosus,and Bacillus subtilis.