Hebei Academy of Science
Hebei Academy of Science
Li Z.,Agricultural University of Hebei |
Zhang Y.,Agricultural University of Hebei |
Ge H.,Hebei Academy of science
Food Chemistry | Year: 2017
Surface browning is an important cause of deterioration of fresh-cut fruit during postharvest handling. In this paper, four pear cultivars with different extents of natural browning were selected to analyse the factors involved in browning. The main results are as follows: the lipoxygenase (LOX) activity of ‘Mantianhong’ and ‘Yali’ pears was higher accompanied by a stronger degree of browning, while the LOX activity in ‘Xueqing’ and ‘Xinli 7’ pears was lower, with less browning. A higher unsaturated fatty acid ratio of pear resulted in reduced browning. The cell membranes disappeared 30 min after being cut in ‘Mantianhong’ pear, which browns easily; however, the cell membranes were still intact 30 min after being cut in ‘Xueqing’ pear, which does not brown easily. Therefore, it can be assumed that the stability of the cell membrane plays an important role in inhibiting browning of fresh-cut pears. © 2017
Kou X.,Beijing Normal University |
Jiang L.,Beijing Normal University |
Yan S.,Hebei Academy of science |
Zhao T.,CAS Institute of Remote Sensing |
And 2 more authors.
Remote Sensing of Environment | Year: 2017
The freeze/thaw (F/T) cycle plays an important role in climate change and ecology research. Currently, soil F/T monitoring is restricted by low satellite spatial resolution or a relative long revisit cycle, which is one of the main problems in improving F/T monitoring resolution using available satellite data. Because temperature is a key parameter in determining soil F/T status, in this study, relatively high-resolution merged land surface temperature data were obtained using the Bayesian Maximum Entropy (BME) method by blending LSTs retrieved from passive microwave and infrared remotely sensed data. The merged temperature data were then used to downscale the passive microwave brightness temperature from 0.25° to 0.05°. Finally, the merged temperature and downscaled brightness temperature data were applied to discriminate the surface freeze/thaw status. A comparison with in situ data turned out that the downscaled brightness temperature could be used to determine soil F/T status with a total classification accuracy higher than 80%. The total freeze/thaw classification accuracy using merged temperature data was only 59.7%, which can be attributed to the temperature difference between the land surface and soil. After the adjustment with a relationship between soil temperature and land surface temperature, the classification accuracy reached 89.7%. © 2017 Elsevier Inc.
Wu A.,Hebei Academy of science |
Zhao Y.,Hebei Academy of science
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2017
Ecological land is of great significance in safeguarding important ecological processes and providing essential ecosystem services, and the classification and evaluation of the ecosystem services of ecological land have become increasingly important in recent years. In order to change the trend of ecological land loss caused by blind economic development and to improve the regional pattern for ecological security, it is necessary to study the rational allocation of the quantitative structure and the spatial patterns of ecological land. Based on land use data of Bashang plateau in 1990, 1995, 2000, 2005, 2010 and 2015, GIS (geographic information system) technology was used to analyze ecological land pattern evolution and ecosystem service values of Bashang plateau. The results were as follows: (1) The ecological land in Bashang plateau was classified into 4 types (forest, grassland, wetland and other ecological land) and 15 sub-types; the quantity of ecological land decreased from 904 500 to 881 800 hm2 during 1990- 2015 due to the decreased grassland and wetland and the increased forest and other ecological land. The quantities of forest and other ecological land increased from 275 000 and 8 300 to 324 900 and 11 300 hm2 respectively, and meanwhile the quantities of grassland and wetland decreased from 501 500 and 119 700 to 437 300 and 108 300 hm2 respectively. (2) The transfer rates of forest, other ecological land, grassland and wetland were 1.45%, 0.73%, -0.51% and -0.38% from 1990 to 2015, respectively. The dynamic degree during 1990-2000 was -0.50%, while it was 2.43% during 2000-2015, which indicated that the activity degree of ecological land in 2000-2015 was much higher than that in 1990-2000. The decrease of grassland and the increase of forest land accelerated, while the reduction of wetland slowed down, and other ecological land change increased. All of these were mainly due to a series of key ecological projects that were carried out in Bashang plateau to control sandstorm source of Tianjin and Beijing, which have led to the rapid growth of forest; meanwhile, as the climate of Bashang plateau tended to be dry after entering 21 century, as well as the unreasonable utilization of grassland and wetland resources, the areas of grassland and wetland decreased. (3) The retention land rates of forest, grassland, wetland and other ecosystem land in the study area were 63.22%, 41.23%, 34.88% and 11.90% respectively, indicating that the spatial stability of forest was the best, followed by grassland and wetland, and the stability of other ecological land was the worst. The ecological evolution process was mainly concentrated in the transfer from grassland to non-ecological land and forest, the transfer from forest to grassland, the transfer from wetland to non-ecological land and the transfer from non-ecological land to grassland and forest. The transfer from non-ecological land to grassland and forest land showed that the series of ecological construction projects had achieved initial success. (4) The ecosystem service values of ecological land decreased from 46.01×108 yuan in 1990 to 428.26×108 yuan in 2015, enlarged by 831%. The average annual growth rate of ecosystem service values increased from 15.82% during 1990-2000 to 17.37% during 2000-2015. The forest ecosystem service values were the maximum, while the other ecological land ecosystem service values were the minimum. We should continue to strengthen the construction of ecological nature preserves, use biological recovery technology and artificial replenishment such as scientific grazing, adjust the industrial structure and use other measures to restore and increase the forest, wetland and grassland ecosystems. © 2017, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
Xu J.,University of Florida |
Jia Z.,Hebei Academy of Science |
Knutson M.D.,University of Florida |
Leeuwenburgh C.,University of Florida
International Journal of Molecular Sciences | Year: 2012
Aging is associated with disturbances in iron metabolism and storage. During the last decade, remarkable progress has been made toward understanding their cellular and molecular mechanisms in aging and age-associated diseases using both cultured cells and animal models. The field has moved beyond descriptive studies to potential intervention studies focusing on iron chelation and removal. However, some findings remain controversial and inconsistent. This review summarizes important features of iron dyshomeostasis in aging research with a particular emphasis on current knowledge of the mechanisms underlying age-associated disorders in rodent models. © 2012 by the authors; licensee MDPI, Basel, Switzerland.
Wang X.-Z.,Hebei University |
He Y.-L.,Hebei University |
Dong L.-C.,Hebei University |
Zhao H.-Y.,Hebei Academy of science
Information Sciences | Year: 2011
Fuzzy measures and fuzzy integrals have been successfully used in many real applications. How to determine fuzzy measures is the most difficult problem in these applications. Though there have existed some methodologies for solving this problem, such as genetic algorithms, gradient descent algorithms and neural networks, it is hard to say which one is more appropriate and more feasible. Each method has its advantages and limitations. Therefore it is necessary to develop new methods or techniques to learn distinct fuzzy measures. In this paper, we make the first attempt to design a special particle swarm algorithm to determine a type of general fuzzy measures from data, and demonstrate that the algorithm is effective and efficient. Furthermore we extend this algorithm to identify and revise other types of fuzzy measures. To test our algorithms, we compare them with the basic particle swarm algorithms, gradient descent algorithms and genetic algorithms in literatures. In addition, for verifying whether our algorithms are robust in noisy-situations, a number of numerical experiments are conducted. Theoretical analysis and experimental results show that, for determining fuzzy measures, the particle swarm optimization is feasible and has a better performance than the existing genetic algorithms and gradient descent algorithms. © 2011 Elsevier Inc. All rights reserved.
Liu R.,Nanjing Agricultural University |
Liu R.,Nanjing Normal University |
Chen L.,Nanjing Agricultural University |
Chen L.,Zhejiang Academy of Agricultural Sciences |
And 6 more authors.
Molecular Plant-Microbe Interactions | Year: 2011
AtMYB44 is a transcription factor that functions in association with the ethylene-signaling pathway in Arabidopsis thaliana. The pathway depends on ETHYLENE INSENSITIVE2 (EIN2), an essential component of ethylene signaling, to regulate defense responses in the plant following treatment with HrpNEa, a harpin protein from a bacterial plant pathogen. Here, we show that AtMYB44 regulates induced expression of the EIN2 gene in HrpNEa-treated Arabidopsis plants. A HrpNEa and ethylene-responsive fragment of the AtMYB44 promoter is sufficient to support coordinate expression of AtMYB44 and EIN2 in specific transgenic Arabidopsis. In the plant, the AtMYB44 protein localizes to nuclei and binds the EIN2 promoter; the HrpNEa treatment promotes AtMYB44 production, binding activity, and transcription of AtMYB44 and EIN2. AtMYB44 overexpression results in increased production of the AtMYB44 protein and the occurrence of AtMYB44-EIN2 interaction under all genetic backgrounds of wild-type Arabidopsis and the etr1-1, ein2-1, ein3-1, and ein5-1 mutants, which have defects in the ethylene receptor ETR1 and the signal regulators EIN2, EIN3, and EIN5. However, AtMYB44 overexpression leads to enhanced EIN2 expression only under backgrounds of wild type, ein3-1, and ein5-1 but not etr1-1 and ein2-1, suggesting that ethylene perception is necessary to the regulation of EIN2 transcription by AtMYB44. © 2011 The American Phytopathological Society.
Xi C.,Hong Kong Polytechnic University |
Hongxing Y.,Hong Kong Polytechnic University |
Lin L.,Hong Kong Polytechnic University |
Jinggang W.,Hebei University of Engineering |
Wei L.,Hebei Academy of science
Energy | Year: 2011
This paper presents experimental studies on a solar-assisted ground coupled heat pump (SAGCHP) system for space heating. The system was installed at the Hebei Academy of Sciences in Shijiazhuang (lat. N38°03', long. E114°26'), China. Solar collectors are in series connection with the borehole array through plate heat exchangers. Four operation modes of the system were investigated throughout the coldest period in winter (Dec 5th to Dec 27th). The heat pump performance, borehole temperature distributions and solar colleting characteristics of the SAGCHP system are analyzed and compared when the system worked in continuous or intermittent modes with or without solar-assisted heating. The SAGCHP system is proved to perform space heating with high energy efficiency and satisfactory solar fraction, which is a promising substitute for the conventional heating systems. It is also recommended to use the collected solar thermal energy as an alternative source for the heat pump instead of recharging boreholes for heat storage because of the enormous heat capacity of the earth. © 2011 Elsevier Ltd.
Zhang X.,Agricultural University of Hebei |
Zhang X.,Hebei Academy of Science |
Guo W.,Agricultural University of Hebei
International Journal of Biological Sciences | Year: 2011
There are many more glycoproteins in Helicoverpa armigera peritrophic membrane than midgut separated by SDS-PAGE analysis after Periodic acid-Schiff (PAS) and coomassie staining. The peritrophic membrane (PM) of H. armigera larvae contains about forty associated proteins. A cDNA library was constructed from H. armigera midgut mRNA to study the new target for pest biocontrol. An antiserum against Spodoptera exigua integral/total PM proteins cross reacted with several H. armigera PM proteins and was used to isolate a complete cDNA encoding an insect intestinal mucin (HaIIM86). The deduced protein sequence of the cDNA contained one potentially glycosylated, mucin-like domain, five cysteine-rich chitin-binding domains (CBDs) and two D-G rich regions. Mucin domain was lined between the first and second CBDs; the two additional D-G rich regions were proposed to internal reside at the amino terminus of the protein flanked by three cysteine-rich CBDs. HaIIM86 contains two D-G-rich tandem repeat domains flanked by cysteine-rich sequences in peritrophic membrane proteins which is not present in all the currently known PM proteins. Howerer the functions of D-G rich domains require further investigation. HaIIM86 was shown as 200kDa protein by SDS-PAGE analysis and appeared to be associated with the PM. HaIIM86 has chitin-binding activity and can be degraded into 90 and 70 kDa by HaGV Enhancin in vivo. The finding has shown that HaIIM86 is the target substrate for enhancin and the potential target for pest control. © Ivyspring International Publisher.
Xu C.,Hebei Academy of science
Wei sheng wu xue bao = Acta microbiologica Sinica | Year: 2011
Quorum-sensing (QS) is a regulatory mechanism with which bacteria regulate the gene expression according to their population density. Pseudomonas aeruginosa regulates the expression of multiple genes via a hierarchical quorum-sensing cascade through LasR and RhlR and their cognate signal molecules N-(3-oxododecanoyl)-L-homoserine lactone (30-C12-HSL) and N-(butanoyl)-L-homoserine lactone (C4-HSL). It aims to explore the regulation of QS on biosynthesis of polyhydroxyalkanoates (PHA) in P. aeruginosa. Wild-type P. aeruginosa PA01 and its QS mutants were used to investigate the effects of quorum-sensing on biosynthesis of PHA by GC and real-time PCR at physiological and molecular level. After treated with QS signal molecule synthesis inhibitor azithromycin, the accumulation of PHA significantly decreased in P. aeruginosa PA01 and its QS mutant strains. The content of PHA in C4-HSL synthase gene rhlI mutant strain PA0210 had no significant difference compared with that of the wild type. However, the PHA contents were significantly affected in 30C12-HSL synthase gene lasl mutant strain PA055, 30C12-HSL transcriptional regulator gene lasR mutant strain PA056 and lasI/lasR double mutant strain PA057. PHA synthase gene phaC1 expression exhibited a significant reduction in lasI mutant and lasR mutant strains. 30C12-HSL signal molecules complementary experiment shows that the expression of phaC1 can be recovered to the level of the wild type, but the synthesis of PHA is only partially restored in lasI mutant strain. The results implicates that lasI/lasR system might be involved in the regulation of intracellular PHA biosynthesis in P. aeruginosa PA01.
Zhao Q.,Hebei Academy of science |
Song S.-S.,Hebei Academy of science
Plant Physiology Communications | Year: 2010
There is a complex interaction between plant and bacteria. Bacterial quorum sensing signals, N-acylhomoserine lactones (AHLs), are also important signals mediating plant and bacterial interaction. AHLs play an important role on plant growth and development. In this review, we would discuss recent findings in the regulation of plant growth and development by AHLs. It would be benefit for us to understand plant communication mechanism with bacteria completely, and to guide on promoting plant growth and enhancing crops production in practice.