Publications (31) View all
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Article: Synthesis of Mn-doped α-Ni(OH)2 nanosheets assisted by liquid-phase laser ablation and their electrochemical properties.
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ABSTRACT: We designed a new strategy, namely, the laser ablation of a target material in an aqueous ionic solution, to prepare Mn-doped Ni(OH)2 nanosheets based on reactions between the pulsed laser-induced plasma plume of Mn and the surrounding NiCl2 solution. The crystalline phase, morphology and structure of the as-derived products are characterised by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. Results indicate the hierarchical assembly of numerous tiny nanosheet building blocks into a Mn-doped α-Ni(OH)2 spherical structure. Importantly, the positive electrode made of Mn-doped α-Ni(OH)2 nanosheets exhibits a high specific capacitance of ∼1000 F g-1 under a current density of 5 A g-1, concurrently possessing excellent cycling ability. This novel strategy may offer researchers an alternative for designing interesting solid targets and ionic solutions towards the fabrication of other new nanostructures for fundamental research and potential applications.Physical Chemistry Chemical Physics 03/2013; · 3.57 Impact Factor -
Article: Whole-genome sequencing of giant pandas provides insights into demographic history and local adaptation.
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ABSTRACT: The panda lineage dates back to the late Miocene and ultimately leads to only one extant species, the giant panda (Ailuropoda melanoleuca). Although global climate change and anthropogenic disturbances are recognized to shape animal population demography their contribution to panda population dynamics remains largely unknown. We sequenced the whole genomes of 34 pandas at an average 4.7-fold coverage and used this data set together with the previously deep-sequenced panda genome to reconstruct a continuous demographic history of pandas from their origin to the present. We identify two population expansions, two bottlenecks and two divergences. Evidence indicated that, whereas global changes in climate were the primary drivers of population fluctuation for millions of years, human activities likely underlie recent population divergence and serious decline. We identified three distinct panda populations that show genetic adaptation to their environments. However, in all three populations, anthropogenic activities have negatively affected pandas for 3,000 years.Nature Genetics 12/2012; 45(1):67-71. · 35.53 Impact Factor -
Article: Relationship of the Estrogen Surge and Multiple Mates to Cub Paternity in the Giant Panda (Ailuropoda melanoleuca): Implications for Optimal Timing of Copulation or Artificial Insemination.
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ABSTRACT: The effectiveness of ex situ breeding programs for endangered species can be limited by challenges in mimicking mating competitions that naturally occur among multiple mates in the wild. The objective of this study was to evaluate the impact of timed natural matings and/or artificial inseminations (AI) in the context of the urinary estrogen surge on cub production in the giant panda (Ailuropoda melanoleuca). We used a large cohort of giant pandas, including 12 females and 17 males. DNA paternity exclusion was used to pinpoint accurately the interval during the estrogen surge that coincided with the ideal sperm deposition time to produce offspring. Of the 31 cubs (in 19 pregnancies), 22 (71.0%; 15 pregnancies) were produced from matings occurring on the day of, or the day after, the maximal urinary estrogen peak. Sixteen of the 19 pregnancies (84.2%) produced at least one offspring sired by the first male mating with the dam. There was a preponderance of twins (12 of 19; 63.2%), and dual paternities were discovered in three of 12 twin sets (25%). These findings indicate a strong relationship between the excreted estrogen surge and sperm deposition to achieve pregnancy in the giant panda. To ensure the production of the most genetically diverse young, it is imperative that the most appropriate male mate first and on the day of, or the day after, the highest detected estrogen value. There is no advantage to increasing the number of copulations or mating partners within 1 day of the estrogen peak on the incidence of twinning, although this practice may increase the prevalence of dual paternity in cases of multiple births.Biology of Reproduction 09/2012; · 4.01 Impact Factor -
Article: A fast and effective method to perform paternity testing for Wolong giant pandas
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ABSTRACT: Captive populations provide a precious genetic resource for endangered animals and a source of individuals for reintroduction to depleted habitats. Therefore, accuracy in determining paternity is of vital importance for managing captive populations and in selecting representative individuals of known genetic characteristics for release. In this study, we established a fast and effective method to conduct paternity testing for captive giant pandas in the Wolong population. This technique uses two highly polymorphic microsatellites initially, subsequent use of five less polymorphic markers and then paternity exclusion testing carried out using the giant panda paternity exclusion program we have developed. Our results revealed that (1) both sets of markers successfully identified the real fathers in 25 cases of paternity testing and (2) the success rate of paternity exclusion varied with the degree of polymorphism of the markers used. Subsequently, we conducted correlation analysis between the success rates of paternity identification with these markers, parameters of genetic diversity and tests of neutrality. We found that the paternity exclusion power of microsatellites was significantly correlated with the number of alleles (Na), expected heterozygosity (H E) and observed homozygosity statistic (F O) (all P < 0.05). From this, we developed a new variable, Na×H E/F O, showing a highly significant positive correlation with the resolution power of microsatellites (P = 0.001). Moreover, the first two highly polymorphic loci gave a 100% success rate of excluding non-paternal males because they yielded higher values of Na×H E/F O than the other five less polymorphic markers. Thus, the Na×H E/F O parameter appears suitable to serve as a criterion for selecting microsatellite markers, which could be used for high-resolution molecular techniques of paternity determination among a range of captive animals besides giant pandas. Keywordsgiant panda–paternity testing–microsatellite–correlationChinese Science Bulletin 04/2012; 56(24):2559-2564. · 1.32 Impact Factor -
Article: The impact of giant panda foraging on bamboo dynamics in an isolated environment
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ABSTRACT: Wildlife species are threatened by massive habitat destruction worldwide. Habitat fragmentation and isolation spatially constrain animals and in turn cause non-sustainable rates of animal foraging on plant populations. However, little empirical research has been done in large controlled settings to investigate foraging impacts. We conducted an experiment to characterize the impact of panda foraging on the sustainability of its food resource, bamboo, in an enclosed area of natural habitat (approximately 19ha). We monitored bamboo density, age, and percent cover throughout the enclosure across a 3-year period. We documented marked declines in bamboo density and percent cover as a result of panda foraging, particularly in younger bamboo age classes. We constructed simultaneous autoregressive models to explain bamboo loss to panda foraging and subsequent bamboo recovery as a function of habitat conditions. Areas with high initial bamboo cover not only were prone to high rates of bamboo percent cover loss but also experienced high rates of subsequent bamboo recovery, as bamboo cover loss opened up the understory for new growth. Variograms of ordinary least squares model residuals revealed that the range of spatial autocorrelation in bamboo loss increased over time as available bamboo forage declined. The results have implications for understanding the impact of animal foraging on vegetation and also highlight the importance of preventing further habitat fragmentation and isolation. KeywordsHabitat fragmentation and isolation–Giant panda–Bamboo–Foraging–Wildlife–VegetationPlant Ecology 04/2012; 212(1):43-54. · 1.83 Impact Factor
