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Pan F.,CAS Institute of Subtropical Agriculture | Pan F.,Cuangxi Normal University | Pan F.,Chinese Academy of Sciences | Zhang W.,CAS Institute of Subtropical Agriculture | And 7 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2011

Ecological stoichiometry theory' which was put forward to investigate nutrient cycling of marine ecosystem by Reiners' has been incorporated successfully into many research fields such as decomposition dynamics' nutrient cycling and biology ecological response to global change and so on. The ratio of carbon: nitrogen: phosphorus (C:N:P) in planktonic biomass was found to be well-constrained in marine ecosystem. Some analyses indicated the existence of analogous ratios in plants' suggesting that the theory may be applicable in terrestrial ecosystems. Here we tested if the ecological stoichiometry theory is applicable to the typical Karst Peak-Cluster Depression' where our previous studies showed that soil nutrient in the upward slope was higher than in the downward slope. It was speculated that the possible reason could be that the litter carbon' nitrogen' phosphorus and carbon: nitrogen: phosphorus (C:N:P) ratio were the same as soil nutrient. It was also inferred that litter C: N: P ratio could play an important role in the decomposition and nutrient cycling of Karst forested ecosystems. In this study' the slope gradients of litter carbon' nitrogen' phosphorus and their mass ratio in four vegetation succession stages was analyzed in order to understand the spatial differentiation and ecological stoichiometry trail of litter nutrient of plant communities in the typical Karst Peak-Cluster Depression. The results of this study showed that (1) carbon, nitrogen, phosphorus and N:P ratio in litter standing crops increased from the early to the later succession stages, while the ratio of C:N and C:P decreased. (2) The content of litter carbon, ratio of C:N, C:P and N:P in upward slope were larger than that in downward slope, while the reverse trend was exhibited in phosphorus content and no significantly different nitrogen content was observed among slopes (P<0.05). The result of Canonical Correspondence Analysis (CCA) showed that the succession stages and slope position had greater impact on the litter accumulation, nutrient distribution and storage, compared to that of slope and bare rock. (3) It is known that the litter decomposition and nutrient cycling is mainly constrained by the N:P ratio. Previous research indicated that litter P concentrations and low N:P ratio did not limit decomposition, but litter N concentrations and high N:P ratios showed contrary results. The lack of significant differences among N elements among slopes and significant difference of P elements reflected that the fluctuations of P content affected vegetation litter N:P ratio and the changing decomposition rate in typical Karst Peak-Cluster Depression. Lower N and high lignin content (namely higher N:P ratio) under the case of low P leading decomposition rate become lower, thus lower N:P ratio is easy for litter decomposition. It is presumed that litter decomposed faster in the downward slope and in young-growth plant communities than that in the upward slope and in old-growth plant communities due to the lower N:P ratio. As a result, less litter nutrient was stored in the downward slope and in young-growth plant communities. Therefore, litter in the upward slope, old-growth forests were conducive to the accumulation of nutrients. Source


Tiyu H.,South China Institute of Endangered Animals | Tiyu H.,Cuangxi Normal University | Yanyan G.,South China Institute of Endangered Animals | Yanyan G.,Cuangxi Normal University | And 4 more authors.
Acta Theriologica Sinica | Year: 2011

During August to November 2009, we captured five males Miniopterus pusillus (Chiroptera: Vesperlilionidae) with partial albinism on their ventral neck in a irrigation works cave around suburb of Zengchen City, and one female Hipposideros pomona (Chiroptera; Hipposideridae) with partial albinism on its head and back neck in a bomb shelter in Conghua City, both in Guangdong Province. We measured the forearm length, ear length, ear width, hind-foot length, tibia length, tail length and body mass of the albino individuals, and found that the parameters of albinisms were all in the range of normal individuals. In this paper, we reported the partial albinism of M. pusillus and H. pomona. Source


Zhang H.,Cuangxi Normal University | Bian H.,Cuangxi Normal University | Yu Q.,Cuangxi Normal University | Liang H.,Cuangxi Normal University
Chemistry Bulletin / Huaxue Tongbao | Year: 2010

The interaction between bovine serum albumin ( BSA ) and phosphomolybdic acid ( PMA ) at physiological condition was investigated by spectroscopies of ultraviolet-visible,fluorescence,synchronous fluorescence and FT-IR. The UV absorbance of BSA decreased and the peaks had red-shift after adding PMA ,which indicated that there was a complex formed. The fluorescence quenching spectra indicated that PMA can quench the fluorescence of BSA with the quenching mechanism. The binding constant (K.) of BSA and PMA was 2.539 x 10 4L-mol-1. The displacement experiment showed that PMA can bind to the site I. The distance between the 214 tryptophan residues in BSA and PMA was estimated to be 1. 93nm using Foster's equation on the basis of fluorescence energy transfer. FT-IR experiments showed that the secondary structure of BSA is changed while adding PMA and the a-helical content of BSA was reduced. Source


Tian J.,Cuangxi Normal University | Zhou L.,Cuangxi Normal University | Lian Y.,Cuangxi Normal University | Zhao Y.,Cuangxi Normal University | Zhao S.,Cuangxi Normal University
Chemistry Bulletin / Huaxue Tongbao | Year: 2012

The interaction of bovine serum albumin (BSA) and Core-shell CdTe/CdS quantum dots (QDs) was investigated by absorption, circular dichroism (CD) and fluorescence spectroscopy. The static quenching exists between QDs and BSA in physiological solution. The quenching constant was obtained at different temperatures (298, 305, 310 K). According to the thermodynamic parameters, it showed that binding power between QDs and BSA is mainly by Van der Waals force or hydrogen bonds forces. The results showed that QDs can quench the fluorescence of BSA with a static quenching mechanism. Synchronous fluorescence spectra, ultraviolet absorption spectroscopy and circular dichroism were used to investigate the conformational changes of BSA. Source

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