Studies of Site Specific DNA Binding of Small Peptides by Competitive Assays with Hoechst 33258

With a view to finding out precisely how small peptides recognize a particular binding site of DNA, we have accomplished DNA binding studies of two peptides, H-Tyr-Arg-OH (YR) and H-Gly-Gly-His-OH (GGH) by using measurements in comparison with the binding between DNA and Hoechst 33258. The inhibition mode by YR and GGH to DNA binding of Hoechst 33258 was analyzed by Lineweaver-Burk plot which shows the plot of typical competitive inhibition at concentration of Hoechst 33258 from 3.66 ( 10-9 mol / L to 1.09 ( 10-8 mol / L. And it is concluded that YR binds to DNA in its minor groove (AT rich regions) with a binding constant K = 1.02 ( 108 (mol / L)-1. The GGH(s specificity is reduced at high concentration because it can also bind GC base pair.

Study on Site Specific Design Earthquake Ground Motion of Nuclear Power Plants in China

The main technical backgrounds and requirements are introduced with regard to earthquake ground motion design parameters in several domestic and American standards,codes and guides involved in the seismic analysis and design activities of nuclear power plants in China.Based on the research results from site seismic safety evaluation of domestic nuclear power plant projects in the last years,characteristics and differences of site specific design spectra are analyzed in comparison with standard response spectra,and the suitability of standard response spectra for domestic nuclear power plant projects is discussed.

Sequence-specific Hydrolysis of Single-stranded DNA by PNA-Cerium （Ⅳ） Adduct

A novel artificial site specific cleavage reagent, with peptide nucleic acid （PNA） as sequence-recognizing moiety and cerium （IV） ions as “scissors” for cleaving target DNA, was synthesized. Subsequently, it was employed in the cleavage of target 26-mer single-stranded DNA （ssDNA）, which has 10-mer sequence complementary with PNA recognizer in the hybrids, under physiological conditions. Reversed-phase high-performance liquid chromatogram （RPHPLC） experiments indicated that the artificial site specific cleavage reagent could cleave the target DNA specifically.

Recent Advances on the Technologies to Increase Fertilizer Use Efficiency

To increase fertilizer use efficiency （FUE） and to minimize its negative impact on environment have been the focal points in the world for a long time. It is very important to increase FUE in China for its relatively low FUE and serious losses of nutrients. Recent advances of the technologies to increase FUE are reviewed in this article. These include site-specific and real-time nitrogen management, non-destructive quick test of the nitrogen status of plants, new types of slow release and controlled release fertilizers, site-specific nutrient management, and use of urease inhibitor and nitrification inhibitor to decrease nitrogen losses. Future outlook in technologies related to FUE improvement is also discussed.

Site-specific PEGylation of Human Growth Hormone by Mutated Sortase A

Human growth hormone（hGH）, a classic therapeutic protein, which promotes growth and wound healing, is released from the pituitary gland. As a protein drug, its short half-life is its main barrier to therapeutic efficacy. Various strategies have been designed to prolong its serum half-life, the most conunon of which is the conjugation with polyethylene glycol（PEG）, as this has been shown to significantly extend protein＇s serum half-life. However, PEGylation often results in random conjugation, which can lead to impaired protein function and hinder purification, characterization and evaluation of the PEGylated protein. Therefore, site specific PEGylation is a promising direction for PEG-protein conjugation. Here we took advantages of the mutated sortase A（7M） enzyme, which can enzymati- cally ligate the universal a-amino acids to a C-terminal tagged protein. This then allows specific modification of the C-terminal of hGH with PEG. This site-specific bound PEG-hGH has similar efficacy, receptor binding and cell proliferation as wild-type hGH; however, pharmacokinetic analysis demonstrates that its serum half-life is almost 24 times that of wild-type hGH. Herein, we provided a promising advancement in the development of site specific PEGylated therapeutic proteins.

Allometric prediction of above-ground biomass of eleven woody tree species in the Sudanian savanna-woodland of West Africa

Allometric models are necessary for estimating biomass in terrestrial ecosystems. Generalized allometric relationship exists for many tropical trees, but species- and region-specific models are often lacking. We developed species-specific allometric models to predict aboveground biomass for 11 native tree species of the Sudanian savanna- woodlands. Diameters at the base and at breast height, with species means ranging respectively from 11 to 28 cm and 9 to 19 cm, and the height of the trees were used as predictor variables. Sampled trees spanned a wide range of sizes including the largest sizes these species can reach. As a response variable, the biomass of the trees was obtained through destructive sampling of 4 754 trees during wood harvesting. We used a stepwise multiple regression analysis with backward elimination procedure to develop models separately predicting, total biomass of the trees, stem biomass, and biomass of branches and twigs. All species- specific regression models relating biomass with measured tree dimen- sions were highly significant （p 〈 0.001）. The biomass of branches and twigs was less predictable compared to stem biomass and total biomass, although their models required fewer predictors and predictor interac- tions. The best-fit equations for total above-ground biomass and stem biomass bad R2 〉 0.70, except for the Acacia species; for branches including twig biomass, R2-values varied from 0.749 for Anogeissus leiocarpa to 0.183 for Acacia macrostachya. The use of these equations in estimating available biomass will avoid destructive sampling, and aid in planning for sustainable use of these species.

Toxicity of Magnetic Albumin Microspheres Bearing Adriamycin

Magnetic albumin microspheres bearing adriamycin (ADM MAM) is a novel chemotherapeutic compound with site specific drug delivery characteristics. The acute and subacute toxic tests of the compound, local irritating test and anaphylactic test were performed on mice and guinea pigs. The results showed there was no macroscopically and microscopically direct cytotoxic injuries of the compound to the animal organs or to the cells. The LD 50 value of the compound was higher than that of the single used adriamycin, indicating that the compound was less toxic than the single adriamycin and quite safe in its therapeutic dosage. Furthermore, there was also no side effects or toxic reactions to be observed on clinical patients with advanced carcinoma or gastric cancer.

Variable Rate Technology and Cotton Yield Response in Texas

Variable Rate Technology （VRT） takes within-field variability into consideration and aims to match resource application to crop requirement. Even though Texas is the most important cotton producing state in the US, the rate of VRT adoption is very low here. Hence, analyzing the factors influencing the adoption and providing a regional estimate of the impact of VRT adoption on cotton yield is very important. This study used the 2009 Southern Cotton Precision Farming Survey to analyze the farm and farmer characteristics affecting the adoption of VRT among Texas cotton farmers and to empirically estimate the impact of adoption of VRT on cotton yield in Texas. A two-stage least square procedure with a logistic regression model in the first stage and a multiple linear regression model in the second stage was used to analyze the data. The study revealed that there are significant regional differences in adoption pattern within the state of Texas; and the farmers from the coastal region, where there is higher within-field variability, were more likely to adopt VRT compared to other regions. Younger farmers, farmers managing larger farms, and farmers who use computers for farming operations were more likely to adopt VRT. The results also showed that, on an average, the adoption of VRT does not lead to significant yield improvements for cotton in Texas. Since the impact of VRT adoption on yield is not significant, the source of economic advantage of VRT adoption in Texas may be the reduction of input cost.

Assessment of the Internal Instability for Granular Soils Subjected to Seepage

The knowledge of the internal stability of granular soils is a key factor for the design of granular and filter for the geotechnical infrastructures such as dykes, barrages, weirs and roads embankment. To evaluate the internal instability of granular soils different criteria are generally used in the practice. However, the results of these criteria on the same soil may lead to different evaluations of the internal instability. In this paper the common criteria used for the internal instability have been presented and compared as far as possible. It was found that the most internal instability criteria define a limit value for the secant slope of the grain size distribution curve of the granular soils. Based on this finding an own criterion for the evaluation of the internal instability of granular soil has been developed and compared to the common criteria. A very good agreement between some criteria was found. Furthermore, a site specific assessment for the evaluation of the internal instability of granular soil has been proposed in order to get more confidence in this evaluation.

Machine Learning and Pattern Analysis Identify Distinctive Influences from Long-term Weekly Net Ecosystem Exchange at Four Deciduous Woodland Locations

A methodology integrating correlation,regression(MLR),machine learning(ML),and pattern analysis of long-term weekly net ecosystem exchange(NEE)datasets are applied to four deciduous broadleaf forest(DBF)sites forming part of the AmeriFlux(FLUXNET2015)database.Such analysis effectively characterizes and distinguishes those DBF sites for which long-term NEE patterns can be accurately predicted using the recorded environmental variables,from those sites cannot be so delineated.Comparisons of twelve NEE prediction models(5 MLR;7 ML),using multi-fold cross-validation analysis,reveal that support vector regression generates the most accurate and reliable predictions for each site considered,based on fits involving between 16 and 24 available environmental variables.SVR can accurately predict NEE for datasets for DBF sites US-MMS and US-MOz,but fail to reliably do so for sites CA-Cbo and MX-Tes.For the latter two sites the predicted versus recorded NEE weekly data follow a Y≠X pattern and are characterized by rapid fluctuations between low and high NEE values across leaf-on seasonal periods.Variable influences on NEE,determined by their importance to MLR and ML model solutions,identify distinctive sets of the most and least influential variables for each site studied.Such information is valuable for monitoring and modelling the likely impacts of changing climate on the ability of these sites to serve as long-term carbon sinks.The periodically oscillating NEE weekly patterns distinguished for sites CA-Cbo and MX-Tes are not readily explained in terms of the currently recorded environmental variables.More detailed analysis of the biological processes at work in the forest understory and soil at these sites are recommended to determine additional suitable variables to measure that might better explain such fluctuations.

Characterizing selected soil attributes of different land-use management to assess reforestation benefits of deforested riparian buffers

Introduction:The information available on the sensitivity of soil biotic and abiotic attributes,which can be used to track the impact of reforestation in riparian buffers,is often insufficient to refine management practices and convince stakeholders of the benefits of reforestation.Methods:In this study,conducted in Victoria,Australia,the changes in soil biotic and abiotic attributes,organic carbon(OC),mineral nitrogen(MN),total dissolved solutes(TDS)and pH were characterised to assess the impact of land-use change from bare riparian(BR)to reforested riparian(RR).Additionally,the benefits of revegetating a deforested creek bank with regard to salinity abatement and C-sequestration potentials were assessed.Results:The TDS depletion in the RR strips varied spatiotemporally from 65 to 169 mg/L,the net OC deposition from 16 to 19 g C/kg soil and MN deposition from 1.2 to 2.1 g N/kg soil,respectively.Additionally,the net changes in pH from alkaline to near neutral condition varied by 0.4 to 1.0 pH units.Approximately 30%to 60%of the net OC depletion after deforestation was redeposited under RR over 3 to 6 years.The TDS depletion after land-use changed from BR to RR ranged from 15 to 32%over 3 to 6 years.Conclusion:The soil attributes OC,MN and TDS characteristics under different land-use practices varied spatiotemporally.This information may be useful to convince stakeholders to undertake reforestation of creek banks for salinity abatement,and that change in land-use has the potential to increase C sequestration at a farm scale.