The origin of the temperature divergence between Holocene proxy reconstructions and model simulations remains controversial, but it possibly results from potential biases in the seasonality of reconstructions or in the climate sensitivity of models. Here we present an extensive dataset of Holocene seasonal temperatures reconstructed using 1310 pollen records covering the Northern Hemisphere landmass. Our results indicate that both summer and winter temperatures warmed from the early to mid-Holocene (~11-7 ka BP) and then cooled thereafter, but with significant spatial variability. Strong early Holocene warming trend occurred mainly in Europe, eastern North America and northern Asia, which can be generally captured by model simulations and is likely associated with the retreat of continental ice sheets. The subsequent cooling trend is pervasively recorded except for northern Asia and southeastern North America, which may reflect the cross-seasonal impact of the decreasing summer insolation through climatic feedbacks, but the cooling in winter season is not well reproduced by climate models. Our results challenge the proposal that seasonal biases in proxies are the main origin of model-data discrepancies and highlight the critical impact of insolation and associated feedbacks on temperature changes, which warrant closer attention in future climate modelling.
Abstract. The Liqiao and Xianping plutons can provide crucial evidence for the collision-orogeny process of the Proto-Tethys Ocean in the western section of the North Qinling Orogen. In this study, we present petrological, zircon U-Pb geochronological, geochemical, and zircon Lu-Hf isotopic data for these plutons. Both the Liqiao and Xianping plutons are characterized as high-K, calc-alkaline, metaluminous to weakly peraluminous granites, with ages of 429 Ma and 421 Ma, respectively. The Liqiao pluton was classified as I-type granite, displaying positive εHf(t) values ranging from -0.1 to +3.4, and high Mg# values from 37.86 to 48.25. We interpret this to indicate that it was generated by the partial melting of juvenile felsic lower crust, with a contribution from mantle-derived material. In contrast, the Xianping pluton exhibited lower Mg# values (20.40 to 35.11) and negative εHf(t) values (-18.0 to -13.9), consistent with the geochemical characteristics of highly fractionated I-type granite. This suggests that the Xianping pluton formed through the partial melting and extensive fractional crystallization of ancient felsic crust. We propose that the Liqiao pluton originated in a syn-collisional setting, while the Xianping pluton formed in a post-collisional environment. Both plutons are products of the collisional orogeny between the Yangtze Block and the North Qinling Orogen, which were associated with the closure of the Wushan-Shangdan Ocean, the northern of the Proto-Tethys Ocean.
In numerical simulations of complex flows with discontinuities, it is necessary to use nonlinear schemes. The spectrum of the scheme used have a significant impact on the resolution and stability of the computation. Based on the approximate dispersion relation method, we combine the corresponding spectral property with the dispersion relation preservation proposed by De and Eswaran (J. Comput. Phys. 218 (2006) 398-416) and propose a quasi-linear dispersion relation preservation (QL-DRP) analysis method, through which the group velocity of the nonlinear scheme can be determined. In particular, we derive the group velocity property when a high-order Runge-Kutta scheme is used and compare the performance of different time schemes with QL-DRP. The rationality of the QL-DRP method is verified by a numerical simulation and the discrete Fourier transform method. To further evaluate the performance of a nonlinear scheme in finding the group velocity, new hyperbolic equations are designed. The validity of QL-DRP and the group velocity preservation of several schemes are investigated using two examples of the equation for one-dimensional wave propagation and the new hyperbolic equations. The results show that the QL-DRP method integrated with high-order time schemes can determine the group velocity for nonlinear schemes and evaluate their performance reasonably and efficiently.
Abstract Carbonate rocks frequently exhibit less predictable seismic attribute–porosity relationships because of complex and heterogeneous pore geometry. Pore geometry plays an important role in carbonate reservoir interpretation, as it influences acoustic and elastic characters. So in porosity prediction of carbonate reservoirs, pore geometry should be considered as a factor. Thus, based on Gassmann’s equation and Eshelby–Walsh ellipsoidal inclusion theory, we introduced a parameter C to stand by pore geometry and then deduced a porosity calculating expression from compressional expression of Gassmann’s equation. In this article, we present a porosity working flow as well as calculate methods of every parameter needed in the porosity inverting equation. From well testing and field application, it proves that the high-accuracy method is suitable for carbonate reservoirs.
The pathogenesis of hallux valgus is not clearly understood.However, genetics research about hallux valgus is rare.Therefore, the present study aimed to explore the pathogeny of hallux valgus from the perspective of genetics.Human samples were collected from normal bone tissue and hallux valgus region bone tissue.The bone samples were studied using real time-PCR, western blot and immunohistochemical.Lentivirus-mediated miR-182 transfected osteoblasts and tested the expression of FGF9 mRNA with real time-PCR.To test alkaline phosphatase activity, number of calcium nodules and proliferation of osteoblast with enzymatic activity analysis, calcium nodules stained and MTT assay.We found that (1) FGF9 expressed in hallux valgus region bone tissue was significantly higher than normal bone tissue.(2) miR-182 expression levels in hallux valgus region bone tissue were notably lower than those of normal bone tissue.(3) miR-182 could negatively regulate the expression of FGF9 in osteoblasts.(4) FGF9 may enhance osteoblasts proliferation.We have demonstrated that miR-182 promotes the formation of bone by targeting FGF9, implicating an essential role of miR-182 in the etiology of hallux valgus.Moreover, miR-182 might potentially be a therapeutic target for hallux valgus treatment.
The global gradual economic recovery has restored the voluntary turnover rate to the level before the outbreak of the epidemic. Cultural differences are considered to be an additional reason for the brain drain of foreign multinational enterprises. A survey was conducted to collect responses from 202 millennial in selected foreign multinational corporations in China. Therefore, the purpose of this study is to explore the relationship between human resource practice (HRPs) mediated by individualism/ collectivism (IC) and turnover intention (TI) by adopting the recognized and well-established social exchange theory, so as to provide new academic ideas for the Millennium employee management of multinational corporations in China. This study was utilized a cross-sectional study as a tools for data collection. For data analysis, this study implemented a Partial-Least Square (PLS) as tools of data analysis. The results highlight the mediating role of individualism/collectivism, reduce Millennium employee turnover intention. In addition, the results verify the negative effect of human resource practice on turnover intention. Therefore, it is important for the management of multinational enterprises in China to develop human resources practices that meet the cultural cognitive of Chinese employees. This study is the first to measure the mediating effect of individualism/collectivism, which defines the theoretical and practical significance and the direction of future research. In addition, more cultural factors will be added to the future research.
Abstract Objective This study aimed to explore the relationship between coping styles, social support and quality of life among disabled older adults and to examine the mediating role of coping styles in the relationship between social support and quality of life. Methods Using a purposive sampling method, three investigators conducted a face‐to‐face questionnaire survey of eligible participants in the geriatric department of a tertiary care hospital in one of the largest cities in southern China between August 2021 and March 2022. A total of 187 questionnaires were collected, of which 176 were valid, with an effective response rate of 94.1%. Results Social support and positive coping were positively related to disabled older adults' quality of life, while negative coping was negatively related to both social support and disabled older adults' quality of life. According to the mediating effect analysis after covariate adjustment, positive coping completely mediated the relationship between social support and older adults' quality of life ( p < 0.01), with the mediating effect size accounting for 76.9% of the total effect. Negative coping had some mediating effect on the relationship between social support and older adults' quality of life ( p < 0.01), with the mediating effect size accounting for 13.0% of the total effect. Conclusion The quality of life of disabled older adults is low, which is closely related to their social support and coping styles. Therefore, it is important to recognize and emphasize the key role that social support systems play in improving the quality of life of this population, broaden their access to social support and guide them to adopt positive coping styles.
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