Effects of habitat fragmentation on the functional diversity of insects in Thousand Island Lake, China

Tian‐Hao Tu,Ji-Rui WANG,Jian-Qiang GU,Tian-Qi LI,Kun LV,Guo-Xin ZHOU,Zhi-Hong XU 한국곤충학회 2019 Entomological Research Vol.49 No.2

Due to habitat fragmentation, the loss of species diversity has been extensively studied. On the contrary, the effects of habitat fragmentation on functional diversity is still poorly understood. In the Thousand Island Lake, we conducted studies of insect functional diversity on a set of 29 isolated islands. We used 10 functional diversity indices from three aspects (functional richness, functional evenness and functional divergence) to respectively describe functional diversity of insects on sample islands. We found the following results: (i) The functional indices selected could reflect the functional diversity of sample islands and it is further proved that in general, three components of functional diversity were independent of each other; (ii) Sample islands could be divided into two categories, island JSD and the remaining islands; (iii) Functional richness increased with island area and shape index, but had no significant correlation with isolation. Likewise, both functional evenness and functional divergence had no significant correlation with island attributes. The conclusion to emphasize from our research is that: (i) habitat fragmentation reduced the biological functional diversity to some extent, further demonstrating the importance of habitat continuity in biodiversity protection; and (ii) for functional diversity protection of insects in a fragmented landscape, an island which has high approximate shape index values of at least hundred hectare magnitude order has a critical promoting effect.

Favorable Impact Toughness of High Heat Input Coarse-Grained HAZ in an Ultra-Low Carbon High-Strength Microalloyed Steel

Fuhui Cui,Junjie Wang1,Xiangdong Gan,Dawei Yu,Ilya Vladimirovich Okulov,Qinghua Tian,Xueyi Guo 대한금속ᆞ재료학회 2023 METALS AND MATERIALS International Vol.29 No.2

Liquid Mg is capable of quickly eroding the refractory Ni-based superalloy and selectively dissolve Ni, which opens up anew avenue for the recycling of superalloy scraps for comprehensive metal reclamation. This study aims at investigating theunderlining mechanism and kinetics of the selective dissolution of Ni from Inconel 718 (one type of Ni-based superalloy)with liquid Mg, by experimenting at 750, 800, and 850 °C for various amounts of time in an inert atmosphere. This selectivedissolution process is also known as liquid metal dealloying. Results show that a permeable dealloyed layer was formedresulting from the preferential dissolution of Ni over other metallic elements (e.g., Fe, Cr, Nb, Mo, and Ti). At the dealloyingforefront, the grain boundaries of the matrix γ phase were preferentially eroded by liquid Mg. The opposite concentrationgradients of Ni (4–9 wt%) and Mg (12–18 wt%) cross the dealloyed layer suggested their counter diffusion. A higher heatingtemperature substantially increased the dealloying rate.

Role of folP1 and folP2 Genes in the Action of Sulfamethoxazole and Trimethoprim Against Mycobacteria

( Tian Zhou Liu ),( Bang Xing Wang ),( Jin Tao Guo ),( Yang Zhou ),( Mugweru Julius ),( Moses Njire ),( Yuan Yuan Cao ),( Tian Wu ),( Zhi Yong Liu ),( Chang Wei Wang ),( Yong Xu ),( Tian Yu Zhang ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.9

The combination of trimethoprim (TMP) and sulfamethoxazole (SMX) has been shown to be active against Mycobacterium tuberculosis (Mtb) in clinical tuberculosis (TB) treatment. However, the mechanism of action of TMP-SMX against Mtb is still unknown. To unravel this, we have studied the effect of TMP and SMX by deleting the folP2 gene in Mycobacterium smegmatis (Msm), and overexpressing the Mtb and Msm folP1/2 genes in Msm. Knocking out of the folP2 gene in Msm reduced the minimum inhibitory concentration of SMX 8-fold compared with wild type. Overexpression of the folP1 genes from Mtb and Msm increased the MICs by 4- and 2-fold in Msm for SMX and TMP, respectively. We show a strong correlation between the expression of folP1 and folP2 genes and TMP-SMX resistance in mycobacteria. This suggests that a combination of FolP2 inhibitor and SMX could be used for TB treatment with a better outcome.

Regulatory Network of MicroRNAs, Host Genes, Target Genes and Transcription Factors in Human Esophageal Squamous Cell Carcinoma

Wang, Tian-Yan,Xu, Zhi-Wen,Wang, Kun-Hao,Wang, Ning Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.9

Abnormally expressed microRNAs (miRNAs) and genes have been found to play key roles in esophageal squamous cell carcinoma (ESCC), but little is known about the underlying mechanisms. The aim of this paper was to assess inter-relationships and the regulatory mechanisms of ESCC through a network-based approach. We built three regulatory networks: an abnormally expressed network, a related network and a global network. Unlike previous examples, containing information only on genes or miRNAs, the prime focus was on relationships. It is worth noting that abnormally expressed network emerged as a fault map of ESCC. Theoretically, ESCC might be treated and prevented by correcting the included errors. In addition, the predicted transcription factors (TFs) obtained by the P-match method also warrant further study. Our results may further guide gene therapy researchers in the study of ESCC.

Melatonin protects endothelial progenitor L255cells against AGE-induced apoptosis via autophagy flux stimulation and promotes wound healing in diabetic mice

Haiming Jin,Zengjie Zhang,Chengui Wang,Qian Tang,Jianle Wang,Xueqin Bai,Qingqing Wang,Majid Nisar,Naifeng Tian,Quan Wang,Cong Mao,Xiaolei Zhang,Xiangyang Wang 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

Wound healing is delayed in diabetic patients. Increased apoptosis and endothelial progenitor cell (EPC) dysfunction are implicated in delayed diabetic wound healing. Melatonin, a major secretory product of the pineal gland, promotes diabetic wound healing; however, its mechanism of action remains unclear. Here, EPCs were isolated from the bone marrow of mice. Treatment of EPCs with melatonin alleviated advanced glycation end product (AGE)-induced apoptosis and cellular dysfunction. We further examined autophagy flux after melatonin treatment and found increased light chain 3 (LC3) and p62 protein levels in AGE-treated EPCs. However, lysosome-associated membrane protein 2 expression was decreased, indicating that autophagy flux was impaired in EPCs treated with AGEs. We then evaluated autophagy flux after melatonin treatment and found that melatonin increased the LC3 levels, but attenuated the accumulation of p62, suggesting a stimulatory effect of melatonin on autophagy flux. Blockage of autophagy flux by chloroquine partially abolished the protective effects of melatonin, indicating that autophagy flux is involved in the protective effects of melatonin. Furthermore, we found that the AMPK/mTOR signaling pathway is involved in autophagy flux stimulation by melatonin. An in vivo study also illustrated that melatonin treatment ameliorated impaired wound healing in a streptozotocin-induced diabetic wound healing model. Thus, our study shows that melatonin protects EPCs against apoptosis and dysfunction via autophagy flux stimulation and ameliorates impaired wound healing in vivo, providing insight into its mechanism of action in diabetic wound healing.

Numerical simulation of ice loads on a ship in broken ice fields using an elastic ice model

Wang, Chao,Hu, Xiaohan,Tian, Taiping,Guo, Chunyu,Wang, Chunhui The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.-

The finite element method is used to simulate the navigation of an ice-area bulk carrier in broken ice fields. The ice material is defined as elastic, and the simulations are accomplished at four model speeds and three ice concentrations. The movements of ice floes in the simulation are consistent with those in the model test, and the percentage deviation of the numerical ice resistance from the ice resistance in the model test can be controlled to be less than 15 %. The key characteristics of ice loads, including the average ice loads, extreme ice loads, and characteristic frequency, are analyzed thoroughly in a comprehensive manner. Moreover, the effects of sailing speed and ice concentration on the ice loads are analyzed. In particular, the stress distribution of ice floes is presented to help understand how model speed and concentration affect the ice loads. The "ice pressure" phenomenon is observed at 90 % ice concentration, and it is realistically reflected both in the time―and frequency―domain ice force curves.

Further Analyzing the Sybil Attack in Mitigating Peer-to-Peer Botnets

( Tian-zuo Wang ),( Huai-min Wang ),( Bo Liu ),( Bo Ding ),( Jing Zhang ),( Pei-chang Shi ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.10

Sybil attack has been proved effective in mitigating the P2P botnet, but the impacts of some important parameters were not studied, and no model to estimate the effectiveness was proposed. In this paper, taking Kademlia-based botnets as the example, the model which has the upper and lower bound to estimate the mitigating performance of the Sybil attack is proposed. Through simulation, how three important factors affect the performance of the Sybil attack is analyzed, which is proved consistent with the model. The simulation results not only confirm that for P2P botnets in large scale, the Sybil attack is an effective countermeasure, but also imply that the model can give suggestions for the deployment of Sybil nodes to get the ideal performance in mitigating the P2P botnet.

Short-selling and security lending under market segmentation: how do they a¤ect the security price?

( Tian Du Wang ),( Cheng Hu Ma ),( Qian Sun ) 한국금융공학회 2014 한국금융공학회 학술발표회 Vol.2014 No.1

We develop a simple model to address the interaction between the security lending market and the security trading market. We identify three types of segmentation that contribute to the relatively small aggregate short interest and the positive lending fee observed in the market. With such segmentation, we show in our model that an exogenous shock on shorting supply/demand should be largely absorbed by the lending market, and thus have minimal impact on the spot price. A positive lending fee implies that the negative opinion of short sellers is offset by the opposite view of security lenders, leaving the equilibrium security price that reflects only the perception of optimistic non-lenders. We further perform static analyses of the change in the scope of the short-selling prohibition, the population mass of potential lenders, the degree of heterogeneity in beliefs, institutional ownership, and margin requirement. The analytical results derived from this model are potentially useful for resolving inconclusive empirical findings regarding the impact of short-selling on security prices.

Naringenin ameliorates atopic dermatitis by inhibiting inflammation and enhancing immunity through the JAK2/STAT3 pathway

Tian Limin,Wang Mengjie,Wang Yangxingyun,Li Wei,Yang Yuenan 한국유전학회 2024 Genes & Genomics Vol.46 No.3

Objective Atopic dermatitis (AD) is an inflammatory skin disease. Naringenin (Nar) possesses an anti-inflammatory property. This paper attempts to discuss the functional mechanism of Nar in AD mice through the Janus kinase 2 (JAK2)/signal transducer and activation of transcription 3 (STAT3) pathway. Methods Mouse models of DNFB-induced AD were established and treated with Nar, followed by intraperitoneal injection with the JAK2/STAT3 pathway activator Coumermycin A1. Dermatitis severity was scored and the thickness of right ear was measured. The pathological changes in dorsal skin tissues were observed by HE staining. The number of infiltrated mast cells and eosinophilic granulocytes was counted by TB staining. The serum IgE level and levels of TNF-α, IL-6, IFN-γ, IL-12, and IL-5 in dorsal skin tissues were measured by ELISA. The levels of p-JAK2, JAK2, p-STAT3, and STAT3 were determined by Western blot. Results Nar decreased dermatitis scores and right ear thickness, alleviated skin lesions, and reduced the number of infiltrated mast cells and eosinophilic granulocytes in AD mice. The serum IgE level and levels of TNF-α, IL-6, IFN-γ, IL-12, and IL-5 in dorsal skin tissues of AD mice were diminished after Nar treatment in a dose-dependent manner. Nar inhibited the activation of the JAK2/STAT3 pathway. The activation of the JAK2/STAT3 pathway partially nullified the therapeutic function of Nar on AD mice. Conclusion Nar protects mice from AD by inhibiting inflammation and promoting immune responses through the inhibition of the JAK2/STAT3 pathway.

Experimental Study of Cooling Speed for Ultra-Thick Steel Plate during the Jet Impinging and Quenching Process

Tian-Liang Fu,Xiang-Tao Deng,Guo-Huai Liu,Zhao-Dong Wang,Guo-Dong Wang 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.17 No.11

The quenching temperature drop curve for Q345B steel plate with 84 mm and 170 mm thickness was tested to analyze the distributing regularities and influencing factors of cooling speed for ultra-thick steel plate during the jet impinging and quenching process. The influences for temperature drop, temperature gradient and cooling speed were analyzed under the conditions of 60~100 m3/h water amount, 0.4~1.0 MPa water pressure, transient switching of quenching mode and the distribution of heat exchanger. Threedimensional heat anti transfer model, surface heat transfer coefficient model and thermal physical parameter model were built up by finite element and optimization. The results showed that the deviation of calculated and measured values was less than 4% for temperature drop curve model. The cooling speed of vertical section for 84 mm-thick steel plate was approximately proportional to surface heat transfer coefficient. The influence of surface heat transfer to cooling speed became weak when the thickness was increased. The influences of temperature effect when switching different quenching modes and temperature gradient of vertical section to cooling speed were stronger. The minimum value of cooling speed was about 1.0~1.8oC/s, between H/6 and H/3 region. These data provide the key information for increasing the cooling speed and uniformity.