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1

Different sensitivities of unicellular and colonial microcystis strains (Cyanophyceae) to six emergent macrophytes

100%
Zhao J., He X., Sun P., Zhang S.
Polish Journal of Environmental Studies
|
2013
|
tom 22
|
nr 5
The effects of six emergent macrophytes (Typha orientalis, Acorus calamus, Oenanthe javanica, Scirpus validus, Sagittaria sagittifolia, and Pontederia cordata) on the growth of two strain Microcystis aeruginosa were studied under co-culture conditions. And the sensitivities of unicellular and colonial Microcystis strains to six emergent macrophytes were compared using an exudation experiment. Based on laboratory experiments, T. orientalis, A. calamus, O. javanica, S. validus, S. sagittifolia, and P. cordata had strong inhibitory effects on growth of unicellular M. aeruginosa, while only A. calamus and P. cordata show obvious growth inhibition on colonial M. aeruginosa. When the biomass density was 20 g FW·L⁻¹, the growth inhibition rate of unicellular M. aeruginosa can exceed 90% for all of the six emergent macrophytes. When macrophytes coexisted with the colonial M. aeruginosa, only A. calamus, P. cordata, and S. sagittifolia showed the growth inhibition of algae. Maximal inhibition of Chl a growth was 75% (p<0.05) for A. calamus, 69% (p<0.05) for P. cordata, and 40% for S. sagittifolia at 45 g FW·L⁻¹ on day 15. The results of the exudation experiment indicated that there were no significant differences between control and treatment of Chl a concentrations of colonial M. aeruginosa for all of the six macrophyte exudations on days 6 and 12. While after 6 d incubation in 100% and 50% macrophyte exudations (40 g FW·L⁻¹), the cell densities of unicellular M. aeruginosa in control were obviously higher than all those in treatment (p < 0.05). The maximal algal growth inhibition (89.62%) of unicellular M. aeruginosa was achieved in 100% exudation of A. calamus on day 6 (p < 0.05). So according to the results of exudation experiments, the unicellular M. aeruginosa was more sensitive than the colonial strain to six emergent macrophytes. And this different sensitivity between Microcystis species probably correlated positively with colony size.
2

Stable carbon and nitrogen isotopes reveal the food diet of Tibetan antelope Pantholops hodgsonii (Abel 1826) in Kekexili Nature Reserve (China)

100%
Sun P., Yu H.-H., Zhao X.-Q., Wang D.-H.
Polish Journal of Ecology
|
2013
|
tom 61
|
nr 2
The stable isotope technique has been widely used to infer the dietary ecology of a range of animal species. The δ¹³C technique provides a valuable tool for researchers when designing pastures for dual environmental and production purposes. Tibetan antelope, Pantholops hodgsoni (chiru), is endemic species to the high-altitude Qinghai-Tibet Plateau of western China – Kekexili Nature Reserve area. The aim of this study was to identify the food diet of Tibetan antelope among plants with C₃ and C₄ photosynthetic pathways. Faeces and plant samples were collected at the Kekexili Nature Reserve (KNR, 34°19’ ~ 36°16’N, 89°25’ ~94°05’E) in Qinghai Province, China. Stable isotope values of carbon and nitrogen of faeces and plant samples were measured under EAMS (element-analysis meter and spectrometer) conditions. Enrichment and food content ratio were calculated according to previous research methods to determine the relative importance of plant sources in the food diet of Tibetan antelopes. The results indicate that faecal samples provided the most convenient and uninjurious sources to predict the food diet and that C₃ plants were selected as the food by chiru. Dualisotope multiple-source mixing model suggested that the food content of antelope is including Gramineae, Cyperaceae, Compositae, Leguminosae, and Cruciferae. An understanding of what chiru selects allows for development of appropriate grazing and protecting strategies, especially in fragile ecosystem. According to our knowledge, this is the first essay to reveal the food diet of chiru with stable isotope analysis method.
3

Opposite-sex sibling recognition in adult root vole, Microtus oeconomus Pallas: phenotype matching or association

100%
Sun P., Zhu W., Zhao X.
Polish Journal of Ecology
|
2008
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tom 56
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nr 4
701-708
Hypothesis of phenotype matching and association are the most likely mechanisms in kin recognition. These hypotheses were tested by observing behavioral responses of cross-fostered root voles to urine cues from familiar and unfamiliar kin and non-kin. In experiment I, approach latency by males was significantly longer in response to non-sibling reared together (NSRT) than to non-sibling reared apart (NSRA) females, whereas, investigatory and sniffing time were significantly less in response to NSRT than to NSRA. However females showed no event bias to odors from NSRT and NSRA males. In experiment II, the behavioral responses of males and females to urine odors from siblings reared apart (SRA) and NSRA were not related to the degree of genetic relationship. It was concluded that: Association mechanism is used by male root voles in opposite-sex sibling recognition; Female voles possibly adopt multiple recognition mechanisms in different social tests.
4

Chemical communication in mammal population: urinary olfactory chemosignals in lactating female root voles (Microtus oeconomus Pallas)

100%
Yu H., Zhao X., Yue P., Sun P.
Polish Journal of Ecology
|
2010
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tom 58
|
nr 1
Urine is a major source of mammalian chemosignals. Among rodents, the sexual attractiveness and chemical constituents of urine vary with different reproductive stages. We confirmed the differing sexual attractiveness to males of the urine of lactating and non-lactating female root voles (Microtus oeconomus) and analyzed individual coding forms and lactation-specific putative pheromones, using gas chromatography-mass spectrometry (GC-MS). First, we documented the behavioral preference of male voles to urine odors of lactating and non-lactating females in a choice maze. The results showed that male voles engaged in more sniffing behavior and spent more time self-grooming in response to urinary odors of lactating females than to urinary odors of non-lactating females. We then used GC-MS to analyze the urine’s individual coding forms and potential chemosignals. We identified 34 volatile compounds, corresponding to 34 GC peaks, in the urine of female voles. The components identified in the urine samples included benzo- forms, alkanes, alkenes, acids, esters, pyrans, alcohols, and other volatile compounds. 12 basic volatiles were detected in all urine samples while others were specific to individuals. (E)5-octadecene and (N) hexadecanoic acid were specific to the lactating stage. A quantitative comparison of the relative abundances of the basic GC peaks showed no difference between the lactating and non-lactating stages, suggesting that individual identity is coded in digital form. We suggest that the urine of lactating females possesses stronger sexual attraction cues because of the presence of (E)5-octadecene and (N)hexadecanoic acid, which are putative lactating pheromones. However, the specific function of the pheromones should be assessed further by bioassay.
5

Effect of burrowing activity of root vole [Microtus oeconomus Pallas] on plant diversity in alpine meadow

100%
Sun P., Zhao X., Zhu W., Xu S.
Polish Journal of Ecology
|
2005
|
tom 53
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nr 4
Herbivory and burrowing activity of mammals may influence the species composition and diversity of plant communities. The effect of corridors and holes systems constructed by root vole (Microtus oeconomus Pallas) on the plant species diversity was studied in the habitat of high - mountain meadow (3250 m a.s.l in Qinghai-Tibet Plateau, China). By using grid method, these disturbances were studied on 16 plots (100 cm × 100 cm) distributed in 4 transects in studied area, in August 2000 and 2001. The disturbance intensity index, D, was calculated as the percent of the ground surface disturbed by voles in the study area. Plant species were identified and counted on the same plots. In total 46 plant species were identified – 39% of this number was considered as sensitive to the vole disturbances as their occurrence and/or abundance decreased along the disturbance intensity. Generally, a significantly negative correlation (r = – 0.911, P < 0.01) between vole aboveground disturbances and plant species diversity (H’) was found. The results suggest that root vole ground disturbances, especially in the form of actively utilized holes and corridors have significantly negative influence on plant species diversity in high-mountain grassland habitat.
6

Two new marine species of Pseudovorticella [Ciliophora, Peritrichia] from Qingdao, North China

100%
Sun P., Song W., Xu D.
Acta Protozoologica
|
2007
|
tom 46
|
nr 1
7

Behavioural reaction of root vole [Microtus oeconomus Pallas] males of different social ranks to familiar and novel odour of conspecific males

100%
Sun P., Zhao Y., Zhao X., Wang D.
Polish Journal of Ecology
|
2007
|
tom 55
|
nr 3
In this experiment, we tested the hypothesis that males of root voles (Microtus oeconomus Pallas) of different social ranks display different behavioural strategies. To document behavioural differences between social ranks, we investigated patterns in the behavioural responses to urine cues from familiar and novel individuals in a choice maze. Ten pairs of male voles were effectively used in this experiment. All behaviour was recorded with OBSERVER 5.0. When experiment was finished, video tapes were transformed into digital data. Then all data were analyzed by SPSS. The results showed that the approach latency of subordinates was shorter for familiar odours than novel ones, dominant individuals preferentially entered the strange odourant box, subordinates preferred familiar odours over novel ones, subordinates spent more time visiting familiar odours compared to the novel odours, dominants preferred novel odours to familiar ones, subordinates approached familiar odours more frequently than novel ones and self-groomed more often in the familiar odourant box than in the novel box, and dominant and subordinate individuals showed significantly different countermarking behaviours to familiar and novel odours. In conclusion, the dominants and subordinates displayed different behaviour patterns when faced to familiar and novel conspecific males’ urine cues. The data support our hypothesis that differences in social rank induce differences in behavioural patterns.
8

Local warming about 1.3 degree Celsius in alpine meadow has no effect on root vole [Microtus oeconomus L.] population during winter

100%
Sun P., Zhao X., Klein J. A., Wei W.
Polish Journal of Ecology
|
2005
|
tom 53
|
nr 1
The influence of air and soil warming on root vole (Microtus oeconomus L.) population was studied in winter period in top open chambers (OTC) (0.8–1.8 m²) warmed by conical fiberglass material and situated in alpine meadow (3250 m) at Qinghai-Tibet Plateau, China. The OTCs were distributed on an area of 30 × 30 m of experimental warming site; another site of the same area was a control one. The root vole population was investigated on two pairs of sites in “low-grazing” and “high-grazing” (by sheep) parts of the meadow; mark-recapture method was used. The winter-season averaged air and soil temperature inside of the chambers were 1.3°C higher than the temperature outside the chambers. The warming in the chambers had no statistically significant effect on root vole numbers, on average body mass of individual, and on average body mass of males and females. In conclusion, as small as 1.3°C warming of soil and air introduced locally and on small (several m²) scale, in the alpine meadow habitat in winter period, has possibly no effect on root vole numbers and biomass.
9

mRNA expression of select hypoxia-inducible genes and apoptotic control genes in zebrafish exposed to hypoxia during development

76%
Ding Z., Sun P., Hua X., Bai Y., Shang E. H. H., Wu R. S. S., Zuo Y.
Polish Journal of Environmental Studies
|
2013
|
tom 22
|
nr 2
Hypoxia is well known to occur in contaminated water environments, but it is still unclear about its effects on transcription of hypoxia-inducible genes and apoptotic control genes in zebrafish during development. In this study, the expression of select genes during zebrafish embryonic development was detected at mRNA level to investigate spatio-temporal changes of hypoxia-inducible genes and apoptosis control genes, as well as the correlation between these genes. Results showed that up-regulation of hypoxia-inducible factor 1 (HIF-1α) mRNA occurred within the first 2 h of exposure to hypoxia, followed by up-regulation of other hypoxia-inducible genes controlled by HIF-1α, such as erythropoietin and vascular endothelial growth factor. 48 hpf (the critical period for embryonic development, especially for the development of a cardiac system) and 40 dpf (the critical period for sex differentiation and development) were found to be the two sensitive windows to hypoxia, at which time significant changes in the mRNA expression of all selected hypoxia-inducible genes were clearly evident. A higher ratio of pro-apoptotic gene (Bax) vs. anti-apoptotic gene (Bcl-2) transcriptions was found in the head as compared with in the tail under hypoxia. A higher Bax/Bcl-2 ratio was found in hypoxic males than in hypoxic females, suggesting that hypoxia potentially favors the formation of testes by inducing apoptosis in ovaries during the hermaphroditism in zebrafish, which in turn causes a malebiased sex ratio.
10
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Development of a SYBR Green I real-time PCR assay for detection of novel porcine parvovirus 7

64%
Li Y. D., Yu Z. D., Bai C. X., Zhang D., Sun P., Peng M. L., Liu H., Wang J., Wang Y.
Polish Journal of Veterinary Sciences
|
2021
|
tom 24
|
nr 1
11
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SYBR Green-based real-time polymerase chain reaction assay for detection of porcine parvovirus 6 in pigs

64%
Sun P., Bai C. X., Zhang D., Wang J., Yang K. K., Cheng B. Z., Li Y. D., Wang Y.
Polish Journal of Veterinary Sciences
|
2020
|
tom 23
|
nr 2
12

The variations of concentrations, profilies and possible sources of metals and polycyclic aromatic hydrocarbons in PM10 from Lanzhou, China

64%
Yu Y., Wang Q., Li L., Sun P., Zhang Y., Lin H., Chen J., Lin B., Xiang M.
Polish Journal of Environmental Studies
|
2016
|
tom 25
|
nr 3
Metals and polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants in airborne particulate matter. In order to better understand the concentrations and origins of metals and PAHs bound to particulate matter in Lanzhou city in northwest China, six metals (Cu, Zn, Ni, Pb, Cd, and Cr) and 16 selected PAHs in 108 part iculate matter samples were quantified by inductively coupled plasma/mass spectrometry (ICP-MS) and gas chromatography/mass spectrometry. Results demonstrated that metals and PAHs in the ambient air of Lanzhou city showed regional and seasonal trends, and their concentrations were higher than those in several other Asian and European cities. The high molecular weight PAHs in winter were higher than in summer in both Xigu District and Yuzhong town. The principle components analysis (PCA) method was applied to analyze the sources of metals bound to particulate matters (PM2.5, PM10, TSP) and PAHs bound to PM10, and results showed that vehicle emissions, coal combustion, and oil combustion were probably the main sources of metal and PAHs in Lanzhou PM.
13

Comparison and redefinition of four marine, coloured Pseudokeronopsis spp. [Ciliophora: Hypotrichida], with emphasis on their living morphology

64%
Song W., Warren A., Roberts D., Wilbert N., Li L., Sun P., Hu X., Ma H.
Acta Protozoologica
|
2006
|
tom 45
|
nr 3
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