Determinants of Loan Loss Provisions in Chinese Banking

The economy in China has developed rapidly since the reform and opening in 1987. Recently, especially after the financial crisis in 2008, the growth of the economy has slowed down. As the main channel of financing in China is indirect financing, banks credit has already taken up 80% of financial market. According to the report which China Banking Regulatory Commission (CBRC) published in 2016, Chinese commercial banks’ impaired loan is 1.53 trillion RMB. The problem of non-performing loans is becoming increasingly severe. In my dissertation, panel data is used to figure out the determinants of loan loss provision in Chinese banking industry. This empirical analysis is performed by collecting data for 34 Chinese banks for the period of 2011 to 2016. Using the System Generalized Method of Moment(S-GMM) and Stochastic Frontier Analysis, I examine whether bank managers employ LLP to smooth their income stream, manage capital adequacy and if these provisions are procyclical in terms of the business cycles. Empirical evidence proves that managers do smooth their income and there exists a pro-cyclical behavior. But it is hard to find evidence to support the capital management theory

The Interplay Between Hydrogen Sulfide and Phytohormone Signaling Pathways Under Challenging Environments

Hydrogen sulfide (H2S) serves as an important gaseous signaling molecule that is involved in intra- and intercellular signal transduction in plant–environment interactions. In plants, H2S is formed in sulfate/cysteine reduction pathways. The activation of endogenous H2S and its exogenous application has been found to be highly effective in ameliorating a wide variety of stress conditions in plants. The H2S interferes with the cellular redox regulatory network and prevents the degradation of proteins from oxidative stress via post-translational modifications (PTMs). H2S-mediated persulfidation allows the rapid response of proteins in signaling networks to environmental stimuli. In addition, regulatory crosstalk of H2S with other gaseous signals and plant growth regulators enable the activation of multiple signaling cascades that drive cellular adaptation. In this review, we summarize and discuss the current understanding of the molecular mechanisms of H2S-induced cellular adjustments and the interactions between H2S and various signaling pathways in plants, emphasizing the recent progress in our understanding of the effects of H2S on the PTMs of proteins. We also discuss future directions that would advance our understanding of H2S interactions to ultimately mitigate the impacts of environmental stresses in the plants

Electronically phase separated nano-network in antiferromagnetic insulating LaMnO3/PrMnO3/CaMnO3 tricolor superlattice

Strongly correlated materials often exhibit an electronic phase separation (EPS) phenomena whose domain pattern is random in nature. The ability to control the spatial arrangement of the electronic phases at microscopic scales is highly desirable for tailoring their macroscopic properties and/or designing novel electronic devices. Here we report the formation of EPS nanoscale network in a mono-atomically stacked LaMnO3/CaMnO3/PrMnO3 superlattice grown on SrTiO3 (STO) (001) substrate, which is known to have an antiferromagnetic (AFM) insulating ground state. The EPS nano-network is a consequence of an internal strain relaxation triggered by the structural domain formation of the underlying STO substrate at low temperatures. The same nanoscale network pattern can be reproduced upon temperature cycling allowing us to employ different local imaging techniques to directly compare the magnetic and transport state of a single EPS domain. Our results confirm the one-to-one correspondence between ferromagnetic (AFM) to metallic (insulating) state in manganite. It also represents a significant step in a paradigm shift from passively characterizing EPS in strongly correlated systems to actively engaging in its manipulation

Engineering zinc oxide hybrid selenium nanoparticles for synergetic anti-tuberculosis treatment by combining Mycobacterium tuberculosis killings and host cell immunological inhibition

IntroductionAs a deadly disease induced by Mycobacterium tuberculosis (Mtb), tuberculosis remains one of the top killers among infectious diseases. The low intracellular Mtb killing efficiency of current antibiotics introduced the long duration anti-TB therapy in clinic with strong side effects and increased drug-resistant mutants. Therefore, the exploration of novel anti-TB agents with potent anti-TB efficiency becomes one of the most urgent issues for TB therapies. MethodsHere, we firstly introduced a novel method for the preparation of zinc oxide-selenium nanoparticles (ZnO-Se NPs) by the hybridization of zinc oxide and selenium to combine the anti-TB activities of zinc oxide nanoparticles and selenium nanoparticles. We characterized the ZnO-Se NPs by dynamic laser light scattering and transmission electron microscopy, and then tested the inhibition effects of ZnO-Se NPs on extracellular Mtb by colony-forming units (CFU) counting, bacterial ATP analysis, bacterial membrane potential analysis and scanning electron microscopy imaging. We also analyzed the effects of ZnO-Se NPs on the ROS production, mitochondrial membrane potential, apoptosis, autophagy, polarization and PI3K/Akt/mTOR signaling pathway of Mtb infected THP-1 macrophages. At last, we also tested the effects of ZnO-Se NPs on intracellular Mtb in THP-1 cells by colony-forming units (CFU) counting. ResultsThe obtained spherical core-shell ZnO-Se NPs with average diameters of 90 nm showed strong killing effects against extracellular Mtb, including BCG and the virulent H37Rv, by disrupting the ATP production, increasing the intracellular ROS level and destroying the membrane structures. More importantly, ZnO-Se NPs could also inhibit intracellular Mtb growth by promoting M1 polarization to increase the production of antiseptic nitric oxide and also promote apoptosis and autophagy of Mtb infected macrophages by increasing the intracellular ROS, disrupting mitochondria membrane potential and inhibiting PI3K/Akt/mTOR signaling pathway. DiscussionThese ZnO-Se NPs with synergetic anti-TB efficiency by combining the Mtb killing effects and host cell immunological inhibition effects were expected to serve as novel anti-TB agents for the development of more effective anti-TB strategy

Improved human papillomavirus DNA typing methods and biology of cervival cancer

Cervical cancer is the second most common cancer among women worldwide. Persistent HPV has been identified as a main risk factor in cervical cancer development. Oncoproteins E6 and E7 of highrisk HPV interact with cellular proteins, subverting cell cycle checkpoint, inducing carcinogenesis. However, only a small proportion of HPV-Minfected women will develop cervical cancer. Other factors may be involved in carcinogenesis, such as other sexually transmitted infections (STIs), genetic predisposition and impaired immune response. Early diagnosis and treatment of cervical precancerous lesions can prevent cervical cancer progression. Widespread use of the Pap smear has decreased the incidence of cervical cancer by 70% in developed countries. HPV DNA testing may further improve the efficiency of cervical cancer screening. In addition, HPV induced cellular protein-biomarkers may act as diagnostic markers in predicting disease progression. HPV vaccines, currently in development, may eventually prevent HPV infection and further decrease the incidence of cervical cancer. Accurate detection and genotyping of HPV is important for the clinics. By using multiple sequencing primers method, we were able to genotype a panel of 65 cervical and 17 oropharyngeal samples for the most clinically important HPV genotypes (HPV 6, 11, 16, 18, 31, 33, and 45) using Pyrosequencing technique. By introducing the sequence pattern recognition, we are able to identify multiple coinfections of HPV types. We also showed that this method is suitable for amplicons with non-specific amplification products and samples with low amplification yields (Paper I). Furthermore, we developed a rapid assay for twelve most common oncogenic HPV genotypes (HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58 and 59) that use a single base, acting as a sentinel to identify the presence of particular HPV genotypes in the specimen. 244 HPV positive cervical specimens were genotyped with this sentinel-base method. The results showed about 25% of them had multiple co-infections of HPV. Thus this sentinel-base method is capable of rapidly genotyping samples containing single or multiple HPV co-infections (Paper II). Other STIs may act as cofactors for cervical carcinogenesis. Co-infection of AAV and HPV can occur in the cervix. AAV-2 Rep78 gene inhibits HPV-induced cell transformation in vitro. To investigate the role of AAV in cervical cancer development, we detected AAV-2 DNA in a retrospective, populationbased nested case-control study. 104 cases and 104 controls were matched by age and time of sampling. Our data showed a link between AAV and cervical cancer. This has to be confirmed in a larger population study base would be required and experiments to show causality (Paper III). Immunological factors play an important role in cervical cancer development. Two genetic variations in chemokine receptors CCR2 and CCR5 were investigated for their association with HPV infection in cervical neoplasia. We analyzed 50 CIS or CIN cases and 50 matched normal controls, and 100 cervical cancer cases and 100 matched healthy controls. All the cases and their responding controls were matched by age and date of sampling. We found that those with the A32/A32 genotype of the CCR5 have a risk of 4.58 (Cl 0.40-52.64, pvalue=0.045), whereas those with CCR2-641 polymorphism did not confer any increased risk for HPV infection. However, there is no evidence of association between these two chemokine receptor gene polymorphisms and the development of cervical neoplasia (Paper IV). During carcinogenesis, oncoproteins E6 and E7 of high-risk HPVs interact with host cellular proteins, particularly through p 1 CINK4A-cyclin D 1 -CDK4/6-pRb-E2F and p 14ARF-MDM2-p53 pathway, resulting in over proliferation and genomic instability of the host cell, further leading to tumorigenesis. We employed immunohistochemistry to investigate the expression of host cellular proteins (biomarkers) p16INK4A, p14ARF, p53 and PCNA on paraffin sections of serial consecutive biopsies from cervical cancer patients. Our results suggested that increased p16INK4A and p14ARF , and decreased or stable p53 expression, are associated with disease progression. The disease developed more quickly among samples staining positive for p16INK4A or p14 ARF, and those with altered p53 expression. Thus, these biomarkers can act as prediction markers for cervical cancer progression (Paper V)

Determinants of Loan Loss Provisions in Chinese Banking

The economy in China has developed rapidly since the reform and opening in 1987. Recently, especially after the financial crisis in 2008, the growth of the economy has slowed down. As the main channel of financing in China is indirect financing, banks credit has already taken up 80% of financial market. According to the report which China Banking Regulatory Commission (CBRC) published in 2016, Chinese commercial banks’ impaired loan is 1.53 trillion RMB. The problem of non-performing loans is becoming increasingly severe. In my dissertation, panel data is used to figure out the determinants of loan loss provision in Chinese banking industry. This empirical analysis is performed by collecting data for 34 Chinese banks for the period of 2011 to 2016. Using the System Generalized Method of Moment(S-GMM) and Stochastic Frontier Analysis, I examine whether bank managers employ LLP to smooth their income stream, manage capital adequacy and if these provisions are procyclical in terms of the business cycles. Empirical evidence proves that managers do smooth their income and there exists a pro-cyclical behavior. But it is hard to find evidence to support the capital management theory

An Efficient and Privacy-Preserving Blockchain-Based Authentication Scheme for Low Earth Orbit Satellite Assisted Internet of Things

Recently, integrating satellite networks (e.g. Low-earth-orbit satellite constellation) into the Internet of Things (IoT) ecosystem has emerged as a potential paradigm to provide more reliable, ubiquitous and seamless network services. The LEO satellite networks serves as a key enabler to transform the connectivity across industries and geographical border. Despite the convenience brought from the LEO satellite networks, it arises security concerns, in which the essential one is to secure the communication between the IoT devices and the LEO satellite network. However, some challenges inheriting from the LEO satellite networks need to be considered : 1) the dynamic topology; 2) the resource-constraint satellites; 3) the relative long latency; 4) multiple beams authentication. In particular, the centralized authentication schemes are no longer suitable for the emerging LEO satellite assisted IoT ecosystem. In this paper, we first introduce the architecture of the LEO satellite network assisted IoT ecosystem. Then, we propose an efficient and privacy-preserving blockchain-based authentication scheme. The proposed authentication scheme takes the advantages of certificateless encryption and consortium blockchain to provide lightweight key pair computation without appealing devices’ information and efficient signature querying and verification. In addition, a fast authentication mechanism is implemented in the scheme in order to reduce the time complexity from querying a certain record for the authentication within a satellite among multiple beams. With the analysis of the storage and computation complexity, the performance evaluation demonstrates the effectiveness of the proposed scheme.peerReviewe

YdfD, a Lysis Protein of the Qin Prophage, Is a Specific Inhibitor of the IspG-Catalyzed Step in the MEP Pathway of Escherichia coli

Bacterial cryptic prophage (defective prophage) genes are known to drastically influence host physiology, such as causing cell growth arrest or lysis, upon expression. Many phages encode lytic proteins to destroy the cell envelope. As natural antibiotics, only a few lysis target proteins were identified. ydfD is a lytic gene from the Qin cryptic prophage that encodes a 63-amino-acid protein, the ectopic expression of which in Escherichia coli can cause nearly complete cell lysis rapidly. The bacterial 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway is responsible for synthesizing the isoprenoids uniquely required for sustaining bacterial growth. In this study, we provide evidence that YdfD can interact with IspG, a key enzyme involved in the MEP pathway, both in vivo and in vitro. We show that intact YdfD is required for the interaction with IspG to perform its lysis function and that the mRNA levels of ydfD increase significantly under certain stress conditions. Crucially, the cell lysis induced by YdfD can be abolished by the overexpression of ispG or the complementation of the IspG enzyme catalysis product methylerythritol 2,4-cyclodiphosphate. We propose that YdfD from the Qin cryptic prophage inhibits IspG to block the MEP pathway, leading to a compromised cell membrane and cell wall biosynthesis and eventual cell lysis