A naïve discussion of Fermat’s last theorem conundrum is described. The present theorem’s proof is grounded on the well-known properties of sums of powers of the sine and cosine functions, the Minkowski norm de...A naïve discussion of Fermat’s last theorem conundrum is described. The present theorem’s proof is grounded on the well-known properties of sums of powers of the sine and cosine functions, the Minkowski norm definition, and some vector-specific structures.展开更多
Node of network has lots of information, such as topology, text and label information. Therefore, node classification is an open issue. Recently, one vector of node is directly connected at the end of another vector. ...Node of network has lots of information, such as topology, text and label information. Therefore, node classification is an open issue. Recently, one vector of node is directly connected at the end of another vector. However, this method actually obtains the performance by extending dimensions and considering that the text and structural information are one-to-one, which is obviously unreasonable. Regarding this issue, a method by weighting vectors is proposed in this paper. Three methods, negative logarithm, modulus and sigmoid function are used to weight-trained vectors, then recombine the weighted vectors and put them into the SVM classifier for evaluation output. By comparing three different weighting methods, the results showed that using negative logarithm weighting achieved better results than the other two using modulus and sigmoid function weighting, and was superior to directly concatenating vectors in the same dimension.展开更多
[Objective] The aim was to study the construction and expression of eukaryotic expression vectors of antibacterial peptides (mytilin and myticin) from Mytilus coruscus.[Method] By the screening of antibacterial pept...[Objective] The aim was to study the construction and expression of eukaryotic expression vectors of antibacterial peptides (mytilin and myticin) from Mytilus coruscus.[Method] By the screening of antibacterial peptide genes of mytilin and myticin of Mytilus coruscus,five antibacterial peptide genes were selected.Then,the relative eukaryotic expressing vectors were constructed by the use of PCR technique and DNA recombinant technology.Subsequently,they were transferred in to S78 Saccharomyces cerevisia by using LiAC transformation method,and then preliminary expressing analysis was carried out.[Result] Five eukaryotic expressing vectors of antibacterial peptides from Mytilus coruscus were successfully constructed,and the results of mRNA detection revealed that the five antibacterial peptides from Mytilus coruscus were successfully transcribed.[Conclusion] The results provide a basis for using genetic engineering to express antibacterial peptides of mytilin and myticin from Mytilus coruscus,and for developing the further study of antibacterial peptides from Mytilus coruscus based on this.展开更多
Delta-12 oleate desaturase gene (FAD2-1) which converts oleic acid into linoleic acid, is the key enzyme determining the fatty acid composition of cottonseed oil. By employing RT-PCR method, full length cDNA of cott...Delta-12 oleate desaturase gene (FAD2-1) which converts oleic acid into linoleic acid, is the key enzyme determining the fatty acid composition of cottonseed oil. By employing RT-PCR method, full length cDNA of cotton delta-12 oleate desat- urase gene GhFAD2-1 containing an open reading frame of 1 158 bp was cloned for constructing RNAi vector. A 515 bp long specific fragment of this gene was se- lected for constructing ihpRNA vector under the control of a seed-specific promoter NAPIN, named pFGC1008-NAPIN-FAD2-1; meanwhile miRNA gene-silencing vector pCAMBIA1302-amiRNA-FAD2-1 targeting GhFAD2-1 was also constructed.展开更多
[Objective] To construct prokaryotic expression vectors encoding gene Erb3binding protein (EBP1), which plays important roles in regulating plant organ size from Nervilia fordii (Hance) Schltr. [Methods] PCR produ...[Objective] To construct prokaryotic expression vectors encoding gene Erb3binding protein (EBP1), which plays important roles in regulating plant organ size from Nervilia fordii (Hance) Schltr. [Methods] PCR products of NfEBP1 with particular restriction sites and expression vectors, pET-28 and pET-16b were digested. Ligation, transformation and selection were performed to construct the recombinant plasmids pET-28-NfEBP1 and pET-16-NfEBP1. The recombinant plasmids were transformed into E. coli BL21 using heat -shock transformation. [Results] Recombinant plasmids pET-28-NfEBP1-1188 and pET-16-NfEBP1-1188 were constructed and transformed into expressional host cells, E. coli BL21, and validated by colony PCR, sequencing and double digestion. [Conclusion] Prokaryotic expression vectors of EBP1 gene from N. fordii were successfully constructed, which laid the foundation for characterization of the gene function.展开更多
Extending the lead time of precipitation nowcasts is vital to improvements in heavy rainfall warning, flood mitigation, and water resource management. Because the TREC vector (tracking radar echo by correlation) rep...Extending the lead time of precipitation nowcasts is vital to improvements in heavy rainfall warning, flood mitigation, and water resource management. Because the TREC vector (tracking radar echo by correlation) represents only the instantaneous trend of precipitation echo motion, the approach using derived echo motion vectors to extrapolate radar reflectivity as a rainfall forecast is not satisfactory if the lead time is beyond 30 minutes. For longer lead times, the effect of ambient winds on echo movement should be considered. In this paper, an extrapolation algorithm that extends forecast lead times up to 3 hours was developed to blend TREC vectors with model-predicted winds. The TREC vectors were derived from radar reflectivity patterns in 3 km height CAPPI (constant altitude plan position indicator) mosaics through a cross-correlation technique. The background steering winds were provided by predictions of the rapid update assimilation model CHAF (cycle of hourly assimilation and forecast). A similarity index was designed to determine the vertical level at which model winds were applied in the extrapolation process, which occurs via a comparison between model winds and radar vectors. Based on a summer rainfall case study, it is found that the new algorithm provides a better forecast.展开更多
Objective:To determine the larvicidal and adult emergence inhibition activities of castor (Ricinus communis) seed extract against three potential mosquito vectors Anopheles stephensi(An. slephensi),Culex quinquefa...Objective:To determine the larvicidal and adult emergence inhibition activities of castor (Ricinus communis) seed extract against three potential mosquito vectors Anopheles stephensi(An. slephensi),Culex quinquefasciatus(Cx.quinquefasciatus) and Aedes albopictus(Ae.albopictus) in India.Methods:The R.communis seed extract was tested,employing WHO procedure,against fourth larval instars of the three mosquito species for 24 h and larval mortalities were recorded at various concentrations(2-64μg/mL):the 24 h LC<sub>50</sub> values of the R.communis seed extract were determined following Probit analysis.The larval killing,antipupation and adult emergence inhibition rates of the test extract,using a single concentration of 2μLC<sub>50</sub>,were studied at different time periods(24-72 h):the extract toxicity was tested against a fish.Oreochromis niloticus(O.niloticus).Results:The R.communis seed extract exhibited larvicidal effects with 100%killing activities at concentrations 32-64μg/mL,and with LC<sub>50</sub> values 7.10.11.64 and 16.84μg/mL for Cx.quinquefasciatus,An.stephensi and Ae.albopictus larvae,respectively. When the larvae were treated with the extract at a single concentration of 2×LC<sub>50</sub>,significant differences were observed,compared to control groups,in rate of pupation(P【0.001) as well as in adult formation(P【0.001).Conclusions:The present findings suggest that the R.communis seed extract provided an excellent potential for controlling An.stephensi,Cx.quinquefasciatus and Ae. albopictus mosquito vectors.展开更多
BACKGROUND: Gene therapy as part of modern molecu-lar medicine holds great promise for the treatment of hepa-tocellular carcinoma (HCC) and has the potential to bringa revolutionary era to cancer treatment. For the pa...BACKGROUND: Gene therapy as part of modern molecu-lar medicine holds great promise for the treatment of hepa-tocellular carcinoma (HCC) and has the potential to bringa revolutionary era to cancer treatment. For the past de-cade various viral and non-viral vectors have been engi-neered for improved liver gene therapy.DATA RESOURCES: An English-language literature searchusing MEDLINE (2004), Index Medicus (2004) and biblio-graphic reviews of books and review articles. Liver-directedgene transfer vectors and their history and recent clinicalapplications.RESULTS: The ultimate goal of liver-directed gene therapyfor HCC is the stable expression of a therapeutic transgenein a significant proportion of hepatocytes. The design of avector system providing efficient and stable gene engraft-ment and expression in human hepatocytes is still a chal-lenging issue. The advantages and disadvantages of the ge-netically engineered vector of viral or non-viral origin arediscussed with respect to their essential relevance.CONCLUSION: Liver gene therapy has a long way to goand efficient and innocuous liver-directed gene transfer vec-tors are therefore urgently required.展开更多
The breeding method has been widely used to generate ensemble perturbations in ensemble forecasting due to its simple concept and low computational cost. This method produces the fastest growing perturbation modes to ...The breeding method has been widely used to generate ensemble perturbations in ensemble forecasting due to its simple concept and low computational cost. This method produces the fastest growing perturbation modes to catch the growing components in analysis errors. However, the bred vectors (BVs) are evolved on the same dynamical flow, which may increase the dependence of perturbations. In contrast, the nonlinear local Lyapunov vector (NLLV) scheme generates flow-dependent perturbations as in the breeding method, but regularly conducts the Gram-Schmidt reorthonormalization processes on the perturbations. The resulting NLLVs span the fast-growing perturbation subspace efficiently, and thus may grasp more com- ponents in analysis errors than the BVs. In this paper, the NLLVs are employed to generate initial ensemble perturbations in a barotropic quasi-geostrophic model. The performances of the ensemble forecasts of the NLLV method are systematically compared to those of the random pertur- bation (RP) technique, and the BV method, as well as its improved version--the ensemble transform Kalman filter (ETKF) method. The results demonstrate that the RP technique has the worst performance in ensemble forecasts, which indicates the importance of a flow-dependent initialization scheme. The ensemble perturbation subspaces of the NLLV and ETKF methods are preliminarily shown to catch similar components of analysis errors, which exceed that of the BVs. However, the NLLV scheme demonstrates slightly higher ensemble forecast skill than the ETKF scheme. In addition, the NLLV scheme involves a significantly simpler algorithm and less computation time than the ETKF method, and both demonstrate better ensemble forecast skill than the BV scheme.展开更多
In this paper the geometric description and general theory of mechanical twinning are reviewed, the twins in general lattices and superlattices are summarized, and the kinetic process by which mechanical twins form is...In this paper the geometric description and general theory of mechanical twinning are reviewed, the twins in general lattices and superlattices are summarized, and the kinetic process by which mechanical twins form is revisited. A case study of mechanical twinning of HfV2+Nb, (cubic) Laves phase, is presented and the synchroshear of selected atomic layers is proposed to explain the physical process of twin formation. If the twins form in this way, then long shear vectors and / or atomicshuffles are not really necessary.展开更多
Objective To construct lentivirus vectors carrying alphastatin gene,test its secretion expression in human umbilical vein endothelia cells(HUVECs)and observe its effects on growth,migration and tube formation of HUVEC...Objective To construct lentivirus vectors carrying alphastatin gene,test its secretion expression in human umbilical vein endothelia cells(HUVECs)and observe its effects on growth,migration and tube formation of HUVECs.Methods We constructed recombinant lentivirus vectors of NT4-alphastatin fusion gene containing neurotrophin-4 signal peptide,pro-region sequences and alphastatin,then transfected the recombinant lentivirus vectors into HUVECs to obtain secretory protein alphastatin and test its anti-angiogenic activities in vitro.Results Our data showed that recombinant self-inactivating lentivirus vectors of NT4-alphastatin were successfully constructed,and stable NT4-alphastatin transduced HUVECs were capable of sustainably secreting alphastatin which significantly suppressed HUVECs migration and differentiation but not VEGF-induced proliferation.Conclusion This report represents the first time on the use of lentivirus-based vectors to deliver alphastatin,the endogenous angiogenesis inhibitor,and reveals the potential utility of anti-angiogenic gene therapy with lentivirus vectors for treating cancer.展开更多
In this paper, from the viewpoint of the time value of money, we study the risk measures for portfolio vectors with discount factor. Cash subadditive risk measures for portfolio vectors are proposed. Representation re...In this paper, from the viewpoint of the time value of money, we study the risk measures for portfolio vectors with discount factor. Cash subadditive risk measures for portfolio vectors are proposed. Representation results are given by two different methods which are convex analysis and enlarging space. Especially, the method of convex analysis make the line of reasoning and the representation result be simpler. Meanwhile, spot and forward risk measures for portfolio vectors are also introduced, and the relationships between them are investigated.展开更多
In order to achieve a high precision in three-dimensional(3D) multi-camera measurement system, an efficient multi-cameracalibration method is proposed. A stitching method of large scalecalibration targets is deduced...In order to achieve a high precision in three-dimensional(3D) multi-camera measurement system, an efficient multi-cameracalibration method is proposed. A stitching method of large scalecalibration targets is deduced, and a fundamental of multi-cameracalibration based on the large scale calibration target is provided.To avoid the shortcomings of the method, the vector differencesof reprojection error with the presence of the constraint conditionof the constant rigid body transformation is modelled, and mini-mized by the Levenberg-Marquardt (LM) method. Results of thesimulation and observation data calibration experiment show thatthe accuracy of the system calibrated by the proposed methodreaches 2 mm when measuring distance section of 20 000 mmand scale section of 7 000 mm × 7 000 mm. Consequently, theproposed method of multi-camera calibration performs better thanthe fundamental in stability. This technique offers a more uniformerror distribution for measuring large scale space.展开更多
Objective: To demonstrate the utility of DNA vaccines for the tailored methods, the efficacy of enhanced immune responses, and the types of increased im- mune responses. Methods: Four recombinant plasmids constructed ...Objective: To demonstrate the utility of DNA vaccines for the tailored methods, the efficacy of enhanced immune responses, and the types of increased im- mune responses. Methods: Four recombinant plasmids constructed in- cluded the coding regions for the core protein (pC) and for the core, E_1 and E_2 together (pCE_1E_2), IL- 12 p35 and p40. These plasmids were transfected into mammalian cells to test their protein expression and were injected into the quadriceps muscles of BALB/ C mice for measurement of specific antibodies and cytotoxic T-lymphocyte (CTL) responses. Results: All the recombinant plasmids were shown to express specific antigens stably in mammalian cells. Codelivery of pIL-12 expression cassettes with pC and pCE_1E_2 in mice resulted in the enhancement of Ag-dependent CTL responses and the reduction of specific Ab response. The CTL activity was: pC= 18.65%±5.71%, pCE_1E_2=20.07%±11.11%, pC +pIL-12=60.11%±17.37%, pCE_1E_2+pIL-12= 67.48%±15.57%, respectively. The average A val- ues of anti-HCV were pC=0.415±0.127, pCE_1E_2= 0.358±0.096, pC+pIL-12=0.210±0.086, pCE_1E_2 +pIL-12=0.258±0.125. Conclusion: Codelivery of pIL-12 with plasmid DNA can enhance the efficacy of immune responses and shift the type of immune responses.展开更多
This study examined the differentiation character and pluripotency of mesenchymal stem cells (MSCs) under different conditions. Adult MSCs were initially isolated from the bone marrow of rats, cultured in vitro and id...This study examined the differentiation character and pluripotency of mesenchymal stem cells (MSCs) under different conditions. Adult MSCs were initially isolated from the bone marrow of rats, cultured in vitro and identified by flow cytometry. After MSCs were transferred to osteogenic and adipogenic medium respectively, the morphological characterization of induced cells was observed. The expression of marker genes was detected by RT-PCR analysis. Then MSCs were transfected with lenti- viral vectors pGC-FU-Sox9-EGFP. Enhanced green fluorescence protein (EGFP) expression and trans- fection efficiency were determined by fluorescence microscopy. The results demonstrated that EGFP caused no effect on the multilineage potential of adult MSCs. Sox9 gene expression of high level was maintained stable in the transfected MSCs and induced MSCs to differentiate into chondrocytes. Ag- gracan was positive in chondrogenic lineages and the expression of aggracan and type Ⅱ collagenwas significantly increased during MSCs chondrogenic differentiation. It was concluded that Sox9 gene-modified adult MSCs may be promising candidate cells for further studies on tissue engineering. EGFP facilitates the research on MSCs physiological behavior and application in tissue engineering during differentiation both in vitro and in vivo.展开更多
We identify the functions whose polynomial multiples are weak* dense in Qp spaces and prove that if |f(z)| ≥ |g(z)| and g is cyclic in Qp, then f is cyclic in Qp. We also show that the multiplication operato...We identify the functions whose polynomial multiples are weak* dense in Qp spaces and prove that if |f(z)| ≥ |g(z)| and g is cyclic in Qp, then f is cyclic in Qp. We also show that the multiplication operator Mx on Qp spaces is cellular indecomposable.展开更多
Lactobacillus species are non-spore-forming, gram-positive bacteria and lactic acid producing bacteria (LAPB) that naturally inhabit the human and animal gastrointestinal and mouth organs. The aim of this review was t...Lactobacillus species are non-spore-forming, gram-positive bacteria and lactic acid producing bacteria (LAPB) that naturally inhabit the human and animal gastrointestinal and mouth organs. The aim of this review was to evaluate the new progress regarding the use of Lactobacillus species as live delivery vectors, prevention, and treatment of pathogenic and metabolic diseases. Lactobacillus strains of probiotics have been extensively studied and have confirmed that they can absolutely improve performance as live delivery vectors, a treatment option of various diseases such as: Hemorrhagic cecal coccidiosis in young poultry, hypertension, avian flu, obesity, diabetes, Derzsy’s disease or parvovirus infection, human immunodeficiency virus infections, irritable bowel syndrome, gastrointestinal disorders, Fungal infections, vaginal eubiosis, fish and shellfish species diseases. We give you an idea about that Lactobacillus species have been proficient in preventing and treating both disorders in animal models and some are used for clinical trials. We present the most current studies on the use of Lactobacillus strains that had an impact on an effective immune response to a specific antigen because a variety of antigens have been expressed. Therefore Lactobacillus strains can be considered as good candidates because of its potential for diseases treatment and vaccine development as heterologous protein secretion to date.展开更多
The operational cloud-motion tracking technique fails to retrieve atmospheric motion vectors (AMVs) in areas lacking cloud; and while water vapor shown in water vapor imagery can be used, the heights assigned to the...The operational cloud-motion tracking technique fails to retrieve atmospheric motion vectors (AMVs) in areas lacking cloud; and while water vapor shown in water vapor imagery can be used, the heights assigned to the retrieved AMVs are mostly in the upper troposphere. As the noise-equivalent temperature difference (NEdT) performance of FY-2E split win- dow (10.3-11.5 μm, 11.6-12.8 μm) channels has been improved, the weak signals representing the spatial texture of water vapor and aerosols in cloud-free areas can be strengthened with algorithms based on the difference principle, and applied in calculating AMVs in the lower troposphere. This paper is a preliminary summary for this purpose, in which the principles and algorithm schemes for the temporal difference, split window difference and second-order difference (SD) methods are introduced. Results from simulation and cases experiments are reported in order to verify and evaluate the methods, based on comparison among retrievals and the "truth". The results show that all three algorithms, though not perfect in some cases, generally work well. Moreover, the SD method appears to be the best in suppressing the surface temperature influence and clarifying the spatial texture of water vapor and aerosols. The accuracy with respect to NCEP 800 hPa reanalysis data was found to be acceptable, as compared with the accuracy of the cloud motion vectors.展开更多
Most national malaria control programmes rely extensively on pyrethroid insecticides to control mosquito vectors of this disease. Unfortunately, the intensive use of this class of insecticides both in public health an...Most national malaria control programmes rely extensively on pyrethroid insecticides to control mosquito vectors of this disease. Unfortunately, the intensive use of this class of insecticides both in public health and agriculture has led to its reduced efficacy. The objective of this review was to assess the role of agricultural pesticides use on the development of resistance to insecticides in malaria vectors and the potential impact of this resistance on control activities. We searched library catalogues and public databases for studies that included data on resistance to the major classes of insecticides: organochlorines, carbamates, organophosphates and pyrethroids, in the malaria vectors of Anopheles genera. There is a strong geographical bias in published studies many originating from West African countries. Several studies demonstrate that resistance to pyrethroids is widespread in the major malaria vectors of the Anopheles gambiae and Anopheles funestus complexes. Assessing the impact of insecticide resistance on vector control is complicated owing to the lack of studies into the epidemiological consequences of resistance on the control of malaria and other vector borne diseases.展开更多
文摘A naïve discussion of Fermat’s last theorem conundrum is described. The present theorem’s proof is grounded on the well-known properties of sums of powers of the sine and cosine functions, the Minkowski norm definition, and some vector-specific structures.
文摘Node of network has lots of information, such as topology, text and label information. Therefore, node classification is an open issue. Recently, one vector of node is directly connected at the end of another vector. However, this method actually obtains the performance by extending dimensions and considering that the text and structural information are one-to-one, which is obviously unreasonable. Regarding this issue, a method by weighting vectors is proposed in this paper. Three methods, negative logarithm, modulus and sigmoid function are used to weight-trained vectors, then recombine the weighted vectors and put them into the SVM classifier for evaluation output. By comparing three different weighting methods, the results showed that using negative logarithm weighting achieved better results than the other two using modulus and sigmoid function weighting, and was superior to directly concatenating vectors in the same dimension.
基金Supported by Agricultural Research Project of Science and Technology Department of Zhejiang Province(2008C22026,2009C32016)Open Topic of Key Open Laboratory of Marine and Estuarine Fishery Resources and Ecology, Ministry of Agriculture ( Open-09-10 )+1 种基金Technology Bureau Project of Zhoushan City (Y20082080)Innovative Business Incubation Program of College Students~~
文摘[Objective] The aim was to study the construction and expression of eukaryotic expression vectors of antibacterial peptides (mytilin and myticin) from Mytilus coruscus.[Method] By the screening of antibacterial peptide genes of mytilin and myticin of Mytilus coruscus,five antibacterial peptide genes were selected.Then,the relative eukaryotic expressing vectors were constructed by the use of PCR technique and DNA recombinant technology.Subsequently,they were transferred in to S78 Saccharomyces cerevisia by using LiAC transformation method,and then preliminary expressing analysis was carried out.[Result] Five eukaryotic expressing vectors of antibacterial peptides from Mytilus coruscus were successfully constructed,and the results of mRNA detection revealed that the five antibacterial peptides from Mytilus coruscus were successfully transcribed.[Conclusion] The results provide a basis for using genetic engineering to express antibacterial peptides of mytilin and myticin from Mytilus coruscus,and for developing the further study of antibacterial peptides from Mytilus coruscus based on this.
文摘Delta-12 oleate desaturase gene (FAD2-1) which converts oleic acid into linoleic acid, is the key enzyme determining the fatty acid composition of cottonseed oil. By employing RT-PCR method, full length cDNA of cotton delta-12 oleate desat- urase gene GhFAD2-1 containing an open reading frame of 1 158 bp was cloned for constructing RNAi vector. A 515 bp long specific fragment of this gene was se- lected for constructing ihpRNA vector under the control of a seed-specific promoter NAPIN, named pFGC1008-NAPIN-FAD2-1; meanwhile miRNA gene-silencing vector pCAMBIA1302-amiRNA-FAD2-1 targeting GhFAD2-1 was also constructed.
基金Supported by Research Fund of the Doctoral Program of Higher Education (200805720004)Scientific Research Foundation for Returned Scholars, Ministry of Education of China ([2009]1001)~~
文摘[Objective] To construct prokaryotic expression vectors encoding gene Erb3binding protein (EBP1), which plays important roles in regulating plant organ size from Nervilia fordii (Hance) Schltr. [Methods] PCR products of NfEBP1 with particular restriction sites and expression vectors, pET-28 and pET-16b were digested. Ligation, transformation and selection were performed to construct the recombinant plasmids pET-28-NfEBP1 and pET-16-NfEBP1. The recombinant plasmids were transformed into E. coli BL21 using heat -shock transformation. [Results] Recombinant plasmids pET-28-NfEBP1-1188 and pET-16-NfEBP1-1188 were constructed and transformed into expressional host cells, E. coli BL21, and validated by colony PCR, sequencing and double digestion. [Conclusion] Prokaryotic expression vectors of EBP1 gene from N. fordii were successfully constructed, which laid the foundation for characterization of the gene function.
基金This study was provided by Natural Science Foundation of Guangdong Province under Grant No. 5001121the China Meteorological Administration under Grant Nos. CMATG2005Y05 and CMATG2008Z10the Guangdong Meteorological Bureau under Grant Nos. 2007A2 and GRMC2007Z03
文摘Extending the lead time of precipitation nowcasts is vital to improvements in heavy rainfall warning, flood mitigation, and water resource management. Because the TREC vector (tracking radar echo by correlation) represents only the instantaneous trend of precipitation echo motion, the approach using derived echo motion vectors to extrapolate radar reflectivity as a rainfall forecast is not satisfactory if the lead time is beyond 30 minutes. For longer lead times, the effect of ambient winds on echo movement should be considered. In this paper, an extrapolation algorithm that extends forecast lead times up to 3 hours was developed to blend TREC vectors with model-predicted winds. The TREC vectors were derived from radar reflectivity patterns in 3 km height CAPPI (constant altitude plan position indicator) mosaics through a cross-correlation technique. The background steering winds were provided by predictions of the rapid update assimilation model CHAF (cycle of hourly assimilation and forecast). A similarity index was designed to determine the vertical level at which model winds were applied in the extrapolation process, which occurs via a comparison between model winds and radar vectors. Based on a summer rainfall case study, it is found that the new algorithm provides a better forecast.
文摘Objective:To determine the larvicidal and adult emergence inhibition activities of castor (Ricinus communis) seed extract against three potential mosquito vectors Anopheles stephensi(An. slephensi),Culex quinquefasciatus(Cx.quinquefasciatus) and Aedes albopictus(Ae.albopictus) in India.Methods:The R.communis seed extract was tested,employing WHO procedure,against fourth larval instars of the three mosquito species for 24 h and larval mortalities were recorded at various concentrations(2-64μg/mL):the 24 h LC<sub>50</sub> values of the R.communis seed extract were determined following Probit analysis.The larval killing,antipupation and adult emergence inhibition rates of the test extract,using a single concentration of 2μLC<sub>50</sub>,were studied at different time periods(24-72 h):the extract toxicity was tested against a fish.Oreochromis niloticus(O.niloticus).Results:The R.communis seed extract exhibited larvicidal effects with 100%killing activities at concentrations 32-64μg/mL,and with LC<sub>50</sub> values 7.10.11.64 and 16.84μg/mL for Cx.quinquefasciatus,An.stephensi and Ae.albopictus larvae,respectively. When the larvae were treated with the extract at a single concentration of 2×LC<sub>50</sub>,significant differences were observed,compared to control groups,in rate of pupation(P【0.001) as well as in adult formation(P【0.001).Conclusions:The present findings suggest that the R.communis seed extract provided an excellent potential for controlling An.stephensi,Cx.quinquefasciatus and Ae. albopictus mosquito vectors.
基金This study was supported by a grant from the National Natural Science Foun-dation of China (No. 30170925).
文摘BACKGROUND: Gene therapy as part of modern molecu-lar medicine holds great promise for the treatment of hepa-tocellular carcinoma (HCC) and has the potential to bringa revolutionary era to cancer treatment. For the past de-cade various viral and non-viral vectors have been engi-neered for improved liver gene therapy.DATA RESOURCES: An English-language literature searchusing MEDLINE (2004), Index Medicus (2004) and biblio-graphic reviews of books and review articles. Liver-directedgene transfer vectors and their history and recent clinicalapplications.RESULTS: The ultimate goal of liver-directed gene therapyfor HCC is the stable expression of a therapeutic transgenein a significant proportion of hepatocytes. The design of avector system providing efficient and stable gene engraft-ment and expression in human hepatocytes is still a chal-lenging issue. The advantages and disadvantages of the ge-netically engineered vector of viral or non-viral origin arediscussed with respect to their essential relevance.CONCLUSION: Liver gene therapy has a long way to goand efficient and innocuous liver-directed gene transfer vec-tors are therefore urgently required.
文摘The breeding method has been widely used to generate ensemble perturbations in ensemble forecasting due to its simple concept and low computational cost. This method produces the fastest growing perturbation modes to catch the growing components in analysis errors. However, the bred vectors (BVs) are evolved on the same dynamical flow, which may increase the dependence of perturbations. In contrast, the nonlinear local Lyapunov vector (NLLV) scheme generates flow-dependent perturbations as in the breeding method, but regularly conducts the Gram-Schmidt reorthonormalization processes on the perturbations. The resulting NLLVs span the fast-growing perturbation subspace efficiently, and thus may grasp more com- ponents in analysis errors than the BVs. In this paper, the NLLVs are employed to generate initial ensemble perturbations in a barotropic quasi-geostrophic model. The performances of the ensemble forecasts of the NLLV method are systematically compared to those of the random pertur- bation (RP) technique, and the BV method, as well as its improved version--the ensemble transform Kalman filter (ETKF) method. The results demonstrate that the RP technique has the worst performance in ensemble forecasts, which indicates the importance of a flow-dependent initialization scheme. The ensemble perturbation subspaces of the NLLV and ETKF methods are preliminarily shown to catch similar components of analysis errors, which exceed that of the BVs. However, the NLLV scheme demonstrates slightly higher ensemble forecast skill than the ETKF scheme. In addition, the NLLV scheme involves a significantly simpler algorithm and less computation time than the ETKF method, and both demonstrate better ensemble forecast skill than the BV scheme.
文摘In this paper the geometric description and general theory of mechanical twinning are reviewed, the twins in general lattices and superlattices are summarized, and the kinetic process by which mechanical twins form is revisited. A case study of mechanical twinning of HfV2+Nb, (cubic) Laves phase, is presented and the synchroshear of selected atomic layers is proposed to explain the physical process of twin formation. If the twins form in this way, then long shear vectors and / or atomicshuffles are not really necessary.
基金supported by the National Natural Science Foundation of China(No.30672162)
文摘Objective To construct lentivirus vectors carrying alphastatin gene,test its secretion expression in human umbilical vein endothelia cells(HUVECs)and observe its effects on growth,migration and tube formation of HUVECs.Methods We constructed recombinant lentivirus vectors of NT4-alphastatin fusion gene containing neurotrophin-4 signal peptide,pro-region sequences and alphastatin,then transfected the recombinant lentivirus vectors into HUVECs to obtain secretory protein alphastatin and test its anti-angiogenic activities in vitro.Results Our data showed that recombinant self-inactivating lentivirus vectors of NT4-alphastatin were successfully constructed,and stable NT4-alphastatin transduced HUVECs were capable of sustainably secreting alphastatin which significantly suppressed HUVECs migration and differentiation but not VEGF-induced proliferation.Conclusion This report represents the first time on the use of lentivirus-based vectors to deliver alphastatin,the endogenous angiogenesis inhibitor,and reveals the potential utility of anti-angiogenic gene therapy with lentivirus vectors for treating cancer.
基金Supported by the National Natural Science Foundation of China(11371284,11771343)
文摘In this paper, from the viewpoint of the time value of money, we study the risk measures for portfolio vectors with discount factor. Cash subadditive risk measures for portfolio vectors are proposed. Representation results are given by two different methods which are convex analysis and enlarging space. Especially, the method of convex analysis make the line of reasoning and the representation result be simpler. Meanwhile, spot and forward risk measures for portfolio vectors are also introduced, and the relationships between them are investigated.
基金supported by the National Natural Science Foundation of China(61473100)
文摘In order to achieve a high precision in three-dimensional(3D) multi-camera measurement system, an efficient multi-cameracalibration method is proposed. A stitching method of large scalecalibration targets is deduced, and a fundamental of multi-cameracalibration based on the large scale calibration target is provided.To avoid the shortcomings of the method, the vector differencesof reprojection error with the presence of the constraint conditionof the constant rigid body transformation is modelled, and mini-mized by the Levenberg-Marquardt (LM) method. Results of thesimulation and observation data calibration experiment show thatthe accuracy of the system calibrated by the proposed methodreaches 2 mm when measuring distance section of 20 000 mmand scale section of 7 000 mm × 7 000 mm. Consequently, theproposed method of multi-camera calibration performs better thanthe fundamental in stability. This technique offers a more uniformerror distribution for measuring large scale space.
文摘Objective: To demonstrate the utility of DNA vaccines for the tailored methods, the efficacy of enhanced immune responses, and the types of increased im- mune responses. Methods: Four recombinant plasmids constructed in- cluded the coding regions for the core protein (pC) and for the core, E_1 and E_2 together (pCE_1E_2), IL- 12 p35 and p40. These plasmids were transfected into mammalian cells to test their protein expression and were injected into the quadriceps muscles of BALB/ C mice for measurement of specific antibodies and cytotoxic T-lymphocyte (CTL) responses. Results: All the recombinant plasmids were shown to express specific antigens stably in mammalian cells. Codelivery of pIL-12 expression cassettes with pC and pCE_1E_2 in mice resulted in the enhancement of Ag-dependent CTL responses and the reduction of specific Ab response. The CTL activity was: pC= 18.65%±5.71%, pCE_1E_2=20.07%±11.11%, pC +pIL-12=60.11%±17.37%, pCE_1E_2+pIL-12= 67.48%±15.57%, respectively. The average A val- ues of anti-HCV were pC=0.415±0.127, pCE_1E_2= 0.358±0.096, pC+pIL-12=0.210±0.086, pCE_1E_2 +pIL-12=0.258±0.125. Conclusion: Codelivery of pIL-12 with plasmid DNA can enhance the efficacy of immune responses and shift the type of immune responses.
文摘This study examined the differentiation character and pluripotency of mesenchymal stem cells (MSCs) under different conditions. Adult MSCs were initially isolated from the bone marrow of rats, cultured in vitro and identified by flow cytometry. After MSCs were transferred to osteogenic and adipogenic medium respectively, the morphological characterization of induced cells was observed. The expression of marker genes was detected by RT-PCR analysis. Then MSCs were transfected with lenti- viral vectors pGC-FU-Sox9-EGFP. Enhanced green fluorescence protein (EGFP) expression and trans- fection efficiency were determined by fluorescence microscopy. The results demonstrated that EGFP caused no effect on the multilineage potential of adult MSCs. Sox9 gene expression of high level was maintained stable in the transfected MSCs and induced MSCs to differentiate into chondrocytes. Ag- gracan was positive in chondrogenic lineages and the expression of aggracan and type Ⅱ collagenwas significantly increased during MSCs chondrogenic differentiation. It was concluded that Sox9 gene-modified adult MSCs may be promising candidate cells for further studies on tissue engineering. EGFP facilitates the research on MSCs physiological behavior and application in tissue engineering during differentiation both in vitro and in vivo.
基金supported by NNSF of China (10771130)Specialized Research Fund for the Doctoral Program of High Education (2007056004)+1 种基金NSF of GuangdongProvince (10151503101000025)NSF of Fujian Province (2009J01004)
文摘We identify the functions whose polynomial multiples are weak* dense in Qp spaces and prove that if |f(z)| ≥ |g(z)| and g is cyclic in Qp, then f is cyclic in Qp. We also show that the multiplication operator Mx on Qp spaces is cellular indecomposable.
文摘Lactobacillus species are non-spore-forming, gram-positive bacteria and lactic acid producing bacteria (LAPB) that naturally inhabit the human and animal gastrointestinal and mouth organs. The aim of this review was to evaluate the new progress regarding the use of Lactobacillus species as live delivery vectors, prevention, and treatment of pathogenic and metabolic diseases. Lactobacillus strains of probiotics have been extensively studied and have confirmed that they can absolutely improve performance as live delivery vectors, a treatment option of various diseases such as: Hemorrhagic cecal coccidiosis in young poultry, hypertension, avian flu, obesity, diabetes, Derzsy’s disease or parvovirus infection, human immunodeficiency virus infections, irritable bowel syndrome, gastrointestinal disorders, Fungal infections, vaginal eubiosis, fish and shellfish species diseases. We give you an idea about that Lactobacillus species have been proficient in preventing and treating both disorders in animal models and some are used for clinical trials. We present the most current studies on the use of Lactobacillus strains that had an impact on an effective immune response to a specific antigen because a variety of antigens have been expressed. Therefore Lactobacillus strains can be considered as good candidates because of its potential for diseases treatment and vaccine development as heterologous protein secretion to date.
基金supported by the National Natural Science Foundation of China(Grant Nos.41175035 and 40475018)the National Basic Research Program of China(Grant No.2009CB421502)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘The operational cloud-motion tracking technique fails to retrieve atmospheric motion vectors (AMVs) in areas lacking cloud; and while water vapor shown in water vapor imagery can be used, the heights assigned to the retrieved AMVs are mostly in the upper troposphere. As the noise-equivalent temperature difference (NEdT) performance of FY-2E split win- dow (10.3-11.5 μm, 11.6-12.8 μm) channels has been improved, the weak signals representing the spatial texture of water vapor and aerosols in cloud-free areas can be strengthened with algorithms based on the difference principle, and applied in calculating AMVs in the lower troposphere. This paper is a preliminary summary for this purpose, in which the principles and algorithm schemes for the temporal difference, split window difference and second-order difference (SD) methods are introduced. Results from simulation and cases experiments are reported in order to verify and evaluate the methods, based on comparison among retrievals and the "truth". The results show that all three algorithms, though not perfect in some cases, generally work well. Moreover, the SD method appears to be the best in suppressing the surface temperature influence and clarifying the spatial texture of water vapor and aerosols. The accuracy with respect to NCEP 800 hPa reanalysis data was found to be acceptable, as compared with the accuracy of the cloud motion vectors.
文摘Most national malaria control programmes rely extensively on pyrethroid insecticides to control mosquito vectors of this disease. Unfortunately, the intensive use of this class of insecticides both in public health and agriculture has led to its reduced efficacy. The objective of this review was to assess the role of agricultural pesticides use on the development of resistance to insecticides in malaria vectors and the potential impact of this resistance on control activities. We searched library catalogues and public databases for studies that included data on resistance to the major classes of insecticides: organochlorines, carbamates, organophosphates and pyrethroids, in the malaria vectors of Anopheles genera. There is a strong geographical bias in published studies many originating from West African countries. Several studies demonstrate that resistance to pyrethroids is widespread in the major malaria vectors of the Anopheles gambiae and Anopheles funestus complexes. Assessing the impact of insecticide resistance on vector control is complicated owing to the lack of studies into the epidemiological consequences of resistance on the control of malaria and other vector borne diseases.