数学方法在市场预测中的运用

文章对市场预测的主要方法进行了讨论,对数学方法在各类预测方法中的运用进行了探讨。

Establishment of a New Method for Genetic Transformation of Dunaliella salina

The exogenous gene was integrated into Dunaliella salina successfully by using LiAc/PEG mediating method for the first time. According to the results of histochemical staining, transgenic D. salina was blue, showing that the exogenous GUS gene was successfully expressed in the cells of D. salina. Meanwhile, the effects of growth state of D. salina, plasmid concentration and temperature on its transformation efficiency were studied, and the transformation conditions were optimized. The results show that the optimum conditions for the genetic transformation of D. salina are shown as follows： D. salina was in the early logarithmic phase; plasmid DNA concentration was 600 μg/ml; temperature was 29 ℃, and transformation efficiency was up to 74.8‰ under the best conditions. According to the results of PCR amplification and PCR-Southern hybridization, the target gene had been integrated into genome and was hereditary.

Establishment of Reverse-transcription Loopmediated Isothermal Amplification Method for Detection of Wheat Streak Mosaic Virus

A reverse-transcription loop-mediated isothermal amplification （RT-LAMP） method was established for the detection of wheat streak mosaic virus （WSMV）. Ac-cording to the conservative regions of the genes that encode the coat protein of WSMV, 2 pairs of primers were designed. Final y, the 1st pair of primers was select-ed through the specificity test. The sensitivity test showed the sensitivity of RT-LAMP method was 10 times higher than that of RT-PCR. In addition, the amplifica-tion of target gene could be judged visual y from the presence of fluorescence （cal-cein） in the final reaction system. The RT-LAMP method, established in this study, was rapid, easy, specific and sensitive. Moreover, it did not require sophisticated equip-ment. The RT-LAMP was suitable for the rapid detection of WSMV.

Comparison of Biolistic and Agrobacterium-mediated Transformation Methods on Transgene Copy Number and Rearrangement Frequency in Rice

Transferring foreign DNA into plant cells by biolistic and Agrobacterium _mediated methods may result in random integration of different copy numbers of the transgene, and different proportions of intact vs. rearranged copies of the transgene. This may, in turn, affect transgene expression levels. To test the above hypothesis, we first introduced the same plasmid, pAc1PG_CAM, into rice (Oryza sativa L.) calli separately by the biolistic method and by the Agrobacterium _mediated method. To show whether different plasmids may affect the results, we also introduced pTOK233 by the Agrobacterium _mediated method and pJPM44 by the biolistic method. Transgene expression of R0 plants was monitored by histochemical analysis of GUS activity. Transgene copy number was determined by Southern blot analysis after digesting genomic DNA with an enzyme that has a unique cutting site within the input plasmid. The total genomic DNA was also digested by a two_cut enzyme (the cuts are located at two sides of a given transgene expression cassette), followed by Southern blotting analysis, for determining the number of intact transgene expression cassettes. Our data showed that Agrobacterium _mediated transformation resulted in lower transgene copy number (average between 2.1 and 2.3) in transgenic rice plants, compared with those plants obtained by the biolistic method (average between 4.2 and 5.6). The frequency of DNA rearrangement in expression cassettes is lower in transgenic rice plants obtained by the Agrobacterium _ mediated method than those obtained by the biolistic method. The average rearrangement frequency is 0.07 to 0.106 for the Agrobacterium _mediated method, and 0.57 to 0.66 for the biolistic method. Our results suggest that it is better to compare the number of intact expression cassettes instead of the total copy number of the transgene in demonstrating their influence on the level of transgene expression. This is the first report on the frequency of expression cassette rearrangement in transgenic plants transformed with the same plasmid by two different transformation methods.

Transgenic Maize Plants Obtained by Pollen-mediated Transformation

The genetic transformation was achieved by pollen_mediated approach on maize ( Zea mays L.) inbred lines Tai 9101 and Zong 31. Plasmid DNA of pGLⅡ_RC_1 was mixed with fresh pollen of maize inbreds in sucrose solution. The pollens were treated by ultrasonication and collected, pollinated on silks of maize ears. Transformants were confirmed by dot blot hybridization, PCR amplification and PCR_Southern blot hybridization. The pollen_mediated transformation approach could circumvent the tedious tissue culture procedures like in particle bombardment and Agrobacterium infection, etc. This approach is simple, easy to operate, and could be widely used in practice.

Novel insight into mechanisms of cholestatic liver injury

Cholestasis results in a buildup of bile acids in serum and in hepatocytes.Early studies into the mechanisms of cholestatic liver injury strongly implicated bile acidinduced apoptosis as the major cause of hepatocellular injury.Recent work has focused both on the role of bile acids in cell signaling as well as the role of sterile inflammation in the pathophysiology.Advances in modern analytical methodology have allowed for more accurate measuring of bile acid concentrations in serum,liver,and bile to very low levels of detection.Interestingly,toxic bile acid levels are seemingly far lower than previously hypothesized.The initial hypothesis has been based largely upon the exposure of μmol/L concentrations of toxic bile acids and bile salts to primary hepatocytes in cell culture,the possibility that in vivo bile acid concentrations may be far lower than the observed in vitro toxicity has far reaching implications in the mechanism of injury.This review will focus on both how different bile acids and different bile acid concentrations can affect hepatocytes during cholestasis,and additionally provide insight into how these data support recent hypotheses that cholestatic liver injury may not occur through direct bile acid-induced apoptosis,but may involve largely inflammatory cell-mediated liver cell necrosis.

Salubrinal protects against tunicamycin and hypoxia induced cardiomyocyte apoptosis via the PERK-eIF2a signaling pathway

Objectives This study examined the protective effect of salubrinal and the mechanism underlying this protection against tunicamycin （TM）- and hypoxia-induced apoptosis in rat cardiomyocytes. Methods Neonatal rat cardiomyocytes were cultured from the ventricles of l-day-old Wistar rats. Cells were exposed to different concentrations of salubrinal （10, 20, and 40 gmol/L） for 30 min followed by TM treatment or hypoxia for 36 h. Apoptosis was measured by a multiparameter HCS （high content screening） apoptosis assay, TUNEL assay and flow cytometry. The phosphorylation of eukaryotic translation initiation factor 2 subunit alpha （eIF2c0 and the expression of cleaved caspase-12 were determined by Western blotting. C/EBP homologous protein （CHOP） was detected by immunocytochemistry. Results HCS, TUNEL assays and flow cytometry showed that salubrinal protected cardiomyocytes against apoptosis induced by TM or hypoxia. Western blotting showed that salubrinal protected cardiomyocytes against apoptosis by inducing eIF2ct phosphorylation and down-regulating the expression of the endoplasmic reticulum stress-mediated apoptotic proteins, CHOP and cleaved caspase-12. Conclusions Our study suggests that salubrinal protects rat cardiomyocytes against TM- or hypoxia-associated apoptosis via a mechanism involving the inhibition of ER stress-mediated apoptosis.

Resonance and Antiresonance in Electronic Transport Process Through a T-Shaped Quantum Waveguide

By means of the transfer matrix approach, the linear conductance spectrum for electronic transport through a T-shaped quantum waveguide is calculated. The resonant peaks and the antiresonant dips in the conductance spectrum are mainly focused. The previous prediction about their positions by other theoretical approaches is checked. In addition, a function of spin filtering is suggested based on the interplay of the resonance and antiresonance in this T-shaped quantum waveguide.

Collision-induced Rotational Energy Transfer in an Atom-Diatom System

As a further theoretical study of the collision-induced quantum interference on rotational energy transfer in an atom-diatom system, based on the first-Born approximation of time-dependent perturbation theory, taking into account the anisotropic Lennard-Jones interaction potential and the long-range interaction potential, the differential interference angles in singlet-triplet mixed states of CO A^1Π（v=9）-e3∑-（v=1） system in collision with He, Ne, Ar, and other partners were calculated theoretically. The relationships of differential interference angle versus impact parameters, including collision parameter b and velocity, are obtained.

PEG－mediated Gene Transfer into Orychophragmus Violaceus Cotyledon Protoplast and Regeneration of Transgenic Plants

Transgenic plants were obtained by PEG-mediated tranfer of foreign gene into cotyledon protoplasts of Orychophragums violaceus. Systematic study was carricd out on PEG-mediatcd transformation of cotyledon protoplast using transient expression system, which showed 25-30 μg of pasmid, 15% PEG and a pH value of 8.0 as the optimal parameters contributing to the highest expression level. Using these parameters, cotyledon protoplasts were isolated, treated with bacterial plasmid DNA (pBI222 with HPT as selective marker) and PEG, and cultured at a density of 5×10 4/ml.After 10-15 days,they were selected by adding 25 μg/ml hygromycine. One month later, a few calli were observed, which were then transferred onto a solid medium with 50-100 μg/ml hygromycine for proliferation. Later they were transferred successively onto differentiation and rooting media and finally hygromycineresistant whole plants were obtaincd. The plants grew well in pots and a regeneration rate of 5 ×10(-5) was achieved. Then,excised leaves of the transgenic plants were used as explants for Southern blot analysis, which confirmed the stable integration of HPT gene into the chromosomal genome of Orychophragmus violaceus The transformation frequency was 10-5.

Recognition algorithm for turn light of front vehicle

Intelligent vehicle needs the turn light information of front vehicles to make decisions in autonomous navigation. A recognition algorithm was designed to get information of turn light. Approximated center segmentation method was designed to divide the front vehicle image into two parts by using geometry information. The number of remained pixels of vehicle image which was filtered by the morphologic feaatres was got by adaptive threshold method, and it was applied to recognizing the lights flashing. The experimental results show that the algorithm can not only distinguish the two turn lights of vehicle but also recognize the information of them. The algorithm is quiet effective, robust and satisfactory in real-time performance.

Comparative study of de novo assembly and genome-guided assembly strategies for transcriptome reconstruction based on RNA-Seq

Transcriptome reconstruction is an important application of RNA-Seq,providing critical information for further analysis of transcriptome.Although RNA-Seq offers the potential to identify the whole picture of transcriptome,it still presents special challenges.To handle these difficulties and reconstruct transcriptome as completely as possible,current computational approaches mainly employ two strategies:de novo assembly and genome-guided assembly.In order to find the similarities and differences between them,we firstly chose five representative assemblers belonging to the two classes respectively,and then investigated and compared their algorithm features in theory and real performances in practice.We found that all the methods can be reduced to graph reduction problems,yet they have different conceptual and practical implementations,thus each assembly method has its specific advantages and disadvantages,performing worse than others in certain aspects while outperforming others in anther aspects at the same time.Finally we merged assemblies of the five assemblers and obtained a much better assembly.Additionally we evaluated an assembler using genome-guided de novo assembly approach,and achieved good performance.Based on these results,we suggest that to obtain a comprehensive set of recovered transcripts,it is better to use a combination of de novo assembly and genome-guided assembly.

China＇s Market Transition： A Third Reform Strategy

This paper tries to explain how China can keep domestic stability under both socialist government and rapid capitalist economic growth. By tracing China＇s reform experience and comparing it with the mainstream reform strategies, the paper argues that, first, Chin＇s reform strategy is fundamentally different from the conventional reform strategies; second, China＇s success to a large extent is the result of Chinese leaders＇ decision making and careful management over reform process rather than of simply market force. Finally, the paper suggests that the active role the Chinese Communist Party plays in economic reform grants its legitimacy, thus enabling it to enjoy political stability under long term rapid economic and social transition.