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1

Resilience of energy and CO2 exchange to a summer heatwave in an alpine humid grassland on the Qinghai-Tibetan Plateau

100%
Zhang F., Cao G.
Polish Journal of Environmental Studies
|
2017
|
tom 26
|
nr 1
Summer heatwaves are expected to be much more frequent and severe with negative effects on terrestrial ecosystem water and carbon budgets, while the impacts on alpine grasslands remain poorly understood. Here we analyzed eddy flux and meteorological dataset of a seven-day (July 26 to August 1) summer heatwave in an alpine humid grassland in northeastern Qinghai-Tibetan Plateau in 2015. Compared with pre-heatwave, only diurnal ecosystem respiration (RES) increased by 30.7%, evidently (P < 0.001) during the heatwave. Diurnal sensible heat fluxes (H) and latent heat fluxes (LET) increased by 18.1% (P = 0.08) and 27.5% (P = 0.02) from 9:00 to 16:00. The heatwave did not lead to substantial increments of daily H and daily LET, while daily Bowen ratio (H/LET) decreased a little (P = 0.07). Daily net ecosystem CO₂ exchange increased by 76.7% (P = 0.03), mainly resulting from remarkable growth in daily RES (P<0.001) and undetectable fluctuation in daily gross primary production (GPP) (P = 0.13). Daily ecosystem water use efficiency (GPP/evapotranspiration) decreased by 20.8%. The little difference of energy and CO₂ fluxes between pre-heatwave and post-heatwave indicated strong resilience to the summer heatwave in the alpine humid grassland. Our results revealed that the present-day summer heatwave exerted a limited influence on energy exchange and vegetation photosynthetic activity but did stimulate ecosystem respiration, which would provide a positive feedback to climate warming with more carbon efflux from alpine grassland.
2

Increased nitrous oxide emissions resulting from nitrogen addition and increased precipitation in an alpine meadow ecosystem

81%
Du Y., Guo X., Cao G., Li Y.
Polish Journal of Environmental Studies
|
2016
|
tom 25
|
nr 1
The effects of nitrogen (N) addition and increased precipitation on nitrous oxide (N2O) emissions in alpine meadow ecosystems are still unclear. In this study, we measured N2O fluxes on the Tibetan plateau under interactions of moderate atmospheric N deposition and increased precipitation using a closed chamber method. Under all applied treatment conditions, the alpine meadow ecosystem acted as a source of N2O. The N2O emission rate reached a maximum of 74.83±14.40 μg m-2 h-1, with a significant increase in emission rate of 68.76% following N addition when compared with the control plot (p<0.05). Increased precipitation, and its interactive combination with N deposition, enhanced the N2O emission rate by 53.90% and 44.52%, respectively. However, there was no significant difference between these two treatments. Increased precipitation would help to mitigate N2O fluxes under global nitrogen deposition conditions.
3

Associations between polymorphism in the 2,4-dienoyl-CoA reductase 1 gene (DECR1) and growth traits of Shanxi White pig

81%
Li B., Guo X., Cao G., Zhou Z.
Animal Science Papers and Reports
|
2011
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tom 29
|
nr 4
A polymorphism within exon 2 of the 2, 4-dienoyl-CoA reductase gene (DECR1) was investigated by PCR-SSCP in 228 Shanxi White pigs. An association between the DECR1 polymorphism and growth traits in Shanxi White pigs was determined with an univariate animal model. The polymorphism was found within exon 2 of the DECR1, giving rise to genotypes AA, BB or AB. This polymorphism exhibited a significant effect of generation and sex (P<0.05, P<0.01) on growth traits and backfat thickness. At the age of six months BB pigs showed the body weight and chest girth higher than AA and AB animals. However, the polymorphism revealed no significant effects on other growth traits (P>0.05) though a trend of BB>AB>AA was showed.
4

Simulating N2O emission from Kobresia humilis Serg. alpine meadow on Tibetan Plateau with the DNDC model

71%
Du Y., Cui X., Cao G., Zhao X., Yang G.
Polish Journal of Ecology
|
2011
|
tom 59
|
nr 3
Field me asured N2O emissions in two years were used to parameterize and validate a process-based model, DNDC, for an alpine Kobresia humilis meadow on the Tibetan Plateau in China. Although this model failed to capture the N2O fluxes in some time periods in the spring or autumn, the modeled results showed overall a good performance in terms of simulating the seasonal variation of N2O fluxes and quantifying the annual total emissions. The relative deviation on the annual basis was about 12.4% and –15.9% for the two years, respectively. The modeled data showed that nitrification contributed about 53% of total N2O production, slightly higher than denitrification. The modeled fluxes were sensitive to soil organic content (SOC), pH, and temperature, but less sensitive to variation of precipitation, soil ammonium and nitrate contents. Further mo difications for the model were suggested to focus on the process of soil freezing and thawing as well as the crop growth sub-model that would improve the model’s performance for quantifying N2O emission from the alpine meadow.
5

Arachidonic acid production by Mortierella alpina using raw crop materials

71%
Cao G., Guan Z., Liu F., Liao X., Cai Y.
Acta Scientiarum Polonorum. Technologia Alimentaria
|
2015
|
tom 14
|
nr 2
Background. Arachidonic acid (ARA) is one of the three essential fatty acids, and it is important for human body to keep healthy and is widely used. At present, expensive materials such as glucose and yeast extract are generally reported to be optimal for ARA production. A new cost-effective fermentation process including cheaper material for ARA production is of great significance. Material and methods. Feasibility of using com meal and powdered soybean for fungal growth and lipid accumulation was evaluated by means of single factor test. N-hexadecane concentration was optimized, and the effect of temperature on biomass and ARA content was examined. Results. Mortierella alpina made better use of the aforementioned material as carbon and nitrogen sources for both hyphae growth and ARA production compared with glucose and yeast extract. Maximal levels of 10.9 g/L ARA and 26.1 g/L total lipids were obtained when 66 g/L com meal, 54 g/L soybean meal and 6% (v/v) n-hexadecane were supplemented. A temperature-shift strategy involved three steps, namely, 30°C (3 days) - 25°C (4 days) - 20°C (4 days), which further improved ARA production by 24.7%. Conclusion. Several factors such as carbon and nitrogen sources, temperature and dissolved oxygen had great influence on biomass and microbial oil production. Mortierella alpina preferred com and soybean meal compared with glucose and yeast extract, which would surely alleviate the high cost of ARA production. Based on this study, the new process is both low cost and practicable.
6

C-banding analysis of eight species Kengyilia [Poaceae: Triticeae]

71%
Zeng J., Cao G., Liu J., Zhang H. Q., Zhou Y. H.
Journal of Applied Genetics
|
2008
|
tom 49
|
nr 1
11-21
To characterize chromosomes and the interspecific relationships within the genus Kengyilia, 8 species were used for Giemsa C-banding analysis. Results indicated that the species differed in C-banding patterns. K. gobicola, K. alatavica and K. batalinii had distinct centromeric bands and no banded chromosomes, while K. hirsuta, K. longiglumis, K. melanthera, K. rigidula and K. thoroldiana had more abundant and diagnostic C-bands with interstitial and terminal bands.
7

Effect of grazing intensity on soil and plant δ15N of an alpine meadow

71%
Du Y., Guo X., Zhou G., Cao G., Li Y.
Polish Journal of Environmental Studies
|
2017
|
tom 26
|
nr 3
The mechanisms underlying the retention of inorganic N were still not well understood in an alpine meadow on the Tibetan Plateau as well as in other high-altitude meadow sites greatly grazed and disturbed. We conducted field soil and dominant species foliar nitrogen natural abundance of stable isotope ratios (δ¹⁵N) under four grazing intensities. It was demonstrated that soil δ¹⁵N decreased significantly from 5.83±0.20‰ to 2.17±0.48‰ at 0-10 cm with the elevation of grazing intensity. Grazing reduced the degree of ecosystem N openness. The δ¹⁵N value of surface soil was mainly affected by soil total nitrogen. Furthermore, the degree of nitrogen limitation increased with grazing elevation for sedge family and Gramineae family plants.
8

Contribution of the vegetation layers in the nitrous oxide emission from Alpine Kobresia humulis Serg. meadow ecosystem on the Tibetan Plateau

71%
Du Y., Cao G., Deng Y., Sun G., Cui X.
Polish Journal of Ecology
|
2010
|
tom 58
|
nr 1
Nitrous oxide (N₂O) was one of the major atmospheric greenhouse gases. Its budget was poorly understood in alpine meadow, a dominant vegetation type on the Tibetan Plateau. To characterize a Kobresia humilis meadow on the plateau, N₂O emission rates were monitored from June 2003 to June 2006 in the study area located at 3280 m a.s.l. Nine plots with 1 m × 1 m each were divided into three treatments, i.e. intact herbaceous community (HCK), removal of aboveground plant biomass (CBK), and removal of both above and belowground plant biomass (BSK), to estimate contribution of plants, r hizosphere and bulk soil to the total N₂O emission. N₂O emission from plant aboveground biomass was calculated by flux difference between HCK and CBK, denoted as F (HCK-CBK), from rhizosphere by F (CBK-BSK), and from bulk soil was the flux in BSK treatment. Static chambers (height 50 cm, area 0.5 × 0.5 m²) were used for gas collection. N₂O emission rate was significantly correlated with soil temperature at 5 cm depth in both HCK and BSK (P <0.001). Both treatments demonstrated a seasonal peak rate in growing season and minimum rate in dormancy period. The mean emission rates in the three years were 39.7±2.9 and 30.6±2.5 μg m⁻² h⁻¹ in HCK and BSK, respectively, with the former significantly higher than the latter (P <0.05). In CBK, however, the emission rate did not show consistent correlation with soil temperature, especially in growing season. Its three-year mean emission rate was 36.2±3.3 μg m⁻² h⁻¹. In the K. humilis meadow, bulk soil contributed much more than plants and rhizosphere. The mean emission rate was 3.5±2.9, 5.7±3.8, and 30.6±2.5 μg m⁻² h⁻¹ (P <0.001) from plants, rhizosphere and bulk soil, and these accounted for 9, 14 and 77%, separately. Our results implied that N₂O emission rate decreased little with grazing as indicated by the difference between HCK and CBK in K. humilis meadow (P <0.05). N₂O emission from alpine meadow could not be ignored in addressing regional greenhouse gases budget on the Tibetan Plateau, considering the vast area and much higher radiative forcing of N₂O.
9
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Molecular characterization and expression patterns of ghrelin in the reindeer (Rangifer tarandus)

51%
Zhang M., Zhu X., Xu X., Jin X., Bao H., Dugger S., Du C., Cao G., Yang Y.
Polish Journal of Veterinary Sciences
|
2018
|
tom 21
|
nr 1
10

Polymorphism and structure of exon 2 of caprine melatonin receptor 1b gene and its relations to fertility and seasonal estrus

51%
Jia L., Chu M. X., Di R., Cao G., Feng T., Chen H., Sun J., Fang L.
Animal Science Papers and Reports
|
2012
|
tom 30
|
nr 2
The first description is presented of nucleotide sequence of exon 2 of caprine melatonin receptor 1b (MT2). No polymorphisms of MT2 gene were detected between high fertility and year-round estrous goat breeds and low fertility and seasonal estrous goat breeds. It is likely that exon 2 of MT2 gene is not associated with fertility or reproductive seasonality in goat breeds. The nucleotide sequence of exon 2 of MT2 gene of Jining Grey goats shows much closer phylogenetic relation to the MT2 of sheep (97%) and cattle (94%) than to that of pig (84%), human (80%) and mouse (74%). A rather high nucleotide identity (62-64%) with the melatonin receptor 1a (MT1) of goat, sheep, human and mouse was also found. The caprine MT2 contains the same NAXXY motif in transmembrane 7 as the other melatonin receptors. Both DRY and CYVCR motifs were detected just downstream from its third transmembrane domain (the same as in sheep and cattle) rather than NRY and CYICH found in other melatonin receptor groups.
11

Effect of Val66Met polymorphism in BDNF on attentional bias in an extroverted Chinese Han population

51%
Gong P., Xi S., Li S., Cao G., Zhang P., Shen G., Zhang F., Shen Y., Ma H.
Acta Neurobiologiae Experimentalis
|
2013
|
tom 73
|
nr 2
Studies have indicated that a functional polymorphism (Val66Met) in a brain-derived neurotrophic factor (BDNF) gene can influences human cognitive functions and mood disorders. In this study, we examined associations of BDNF Val66Met with attentional bias and personality in an unaffected population. The results showed that BDNF Val66Met was significantly associated with attentional disengagement for positive cueing words in extraverts. Moreover, there was a positive correlation between the dosages of Met allele and attentional disengagement, however, we did not observe any significant influences of BDNF Val66Met on personality traits. These preliminary results indicate that the individual differences in attentional bias for positive words are partially underpinned by BDNF.
12

Effects of landuse change on CH4 soil-atmospheric exchange in alpine meadow on the Tibetan Plateau

51%
Guo X., Du Y., Han D., Xu X., Zhang F., Lin L., Li Y., Liu S., Ouyang J., Cao G.
Polish Journal of Environmental Studies
|
2015
|
tom 24
|
nr 4
Degradation of shrub meadows and reclamation of alpine meadows may heavily affect the soil sink for atmospheric methane (CH₄), but this is poorly understood. Therefore, in situ measurements of atmospheric CH₄ consumption were conducted in four landuse types: natural alpine meadow (NM), Elymus nutans pasture (EP), herbaceous meadow in shrub (HS), and a P. fruticosa shrub meadow (PS) within two years. CH₄ fluxes were measured using static chambers and gas chromatography. All four types of land use showed atmospheric CH₄ sink throughout the two years, with mean soil CH₄ consumption rates at 24.6±10.9, 33.8±15.0, 39.8±10.3, and 28.1±12.1 µg CH₄·m⁻²·hr⁻¹ for NM, EP, PS, and HS, respectively. Soil CH₄ consumption increased by 40% by reclamation from NM to EP, while it decreased by 30% by degradation from PS to HS. Soil CH₄ consumption in four types of land use was significantly correlated with temperature at 5 cm depth (P<0.01) and the soil water-filled pore space (WFPS) (P<0.05). Temperature showed stronger effects on soil CH₄ consumption than WFPS, except in NM. UV radiation was positively correlated with soil CH₄ consumption with increasing temperature and decreasing soil moisture. These findings indicate that a decrease in the grazing pressure in shrub meadows and increase in the area of artificial pasture reclaimed from alpine meadows would enhance the CH₄ sink in alpine meadows on the Tibetan Plateau.
13

Aerobic methane emission from plant: comparative study of different communities and plant species of Alpine meadow

51%
Guo X., Du Y., Li J., Liu S., Han D., Li Y., Lin L., Zhang F., Oyang J., Cao G.
Polish Journal of Ecology
|
2015
|
tom 63
|
nr 2
This study was aimed at qualifying the methane emission ability of different communities in alpine meadow, and monitoring if the dominant species from these communities could emit methane in a sand culture experiment. Using the static chamber technique and gas chromatography method, two experiments were conducted in the field and in laboratory. First, the methane flux rate was measured in plant communities: natural alpine meadows (NM), Elymus nutans pasture (EP), herbaceous community in shrub (HS), and a Poa fruticosa meadow (PS). A 3-month sand culture experiment was conducted to show the non-microbial methane emission from living plants. Average methane emission rates were estimated to be 16.83 µg m⁻² h⁻¹(range -49.3–107.8), 28.49 µg m⁻² h⁻¹ (range -55.0–96.2) and 20.91 µg m⁻² h⁻¹ (range -31.9– 145.8) for NM, EP, and PS, respectively. Methane emission rate from EP was significantly higher than from NM during the growing season. The reclaim of grassland would enhance the methane emission in this aera through this one year's measurement, but whether this conclusion suit to the whole Tibet Plateau, it remains further longer time and larger spatial scale experiments to verify it. The result of the sand culture experiment showed that some plant species emitted methane in an aerobic, nonmicrobial environment, most of herbaceous species showed a methane emission characteristic, the methane emission from plant may have a species dependent characteristic.
14

Polymorphism of AA-NAT gene and its relationship with litter size of Jining Grey goat of China

42%
Chu M., Yan Y., Wang P., Guligena, Yang H., Hao G., Yu J., Tang Q., Feng T., Cao G., Huang D., Di R., Liu Q., Li N.
Animal Science Papers and Reports
|
2013
|
tom 31
|
nr 1
The polymorphisms of arylalkylamine-N-acetyltransferase (AA-NAT) gene in high-prolificacy Jining Grey goat, medium-prolificacy Boer goat and low-prolificacy Liaoning Cashmere, Inner Mongolia Cashmere and Angora goats were detected to analyse their relationships with litter size.Primers (P1-P5) were designed to detect the polymorphisms by PCR-SSCP and PCR-RFLP. For P2,AA, AB and BB genotypes were detected. Sequencing revealed one silent mutation (T132C) of AANAT gene in BB in comparison to AA. For P3, CC and CD genotypes were detected and sequencing revealed one mutation (C265T) of AA-NAT gene in CD in comparison to CC, and this mutation resulted in an amino acid change of Arg→Cys (R89C). The Jining Grey does with genotype CD delivered by 0.56 kids (P<0.05) more than those with CC genotype. For P5, EE, EF and FF genotypes were detected and sequencing revealed one mutation (C586T) of AA-NAT gene in FF in comparison to EE. This mutation caused an amino acid change of Arg→Trp (R196W). For both P2 and P5, the differences in litter size among three genotypes were not significant in Jining Grey goats (P>0.05).These results preliminarily indicate that allele D at the C265T locus of AA-NAT gene is a potential marker in genetic improvement of litter size in goats.
15

Effects of increased precipitation and nitrogen deposition on methane uptake of Alpine meadow in Qinghai-Tibet Plateau: in situ experiments

42%
Guo X., Dail L., Zhang F., Li Y., Lin L., Li Q., Dawen Q., Fan B., Ke X., Cao G., Zhou H., Du Y.
Polish Journal of Ecology
|
2020
|
tom 68
|
nr 2
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