This paper studies the role of lease financing in disaster-affected firms under collateral constraints. Disaster-affected firms demand funds for post-disaster reconstruction. However, the destruction ...of natural disasters leads to collateral constraints, which create external financing frictions. I find that affected firms obtain financing through operating leases after natural disasters. The significance of the findings highlights the importance of operating leases for collateral-constrained firms.
Boardroom networks and corporate investment Song, Suyong; Wang, Jiawei (Brooke)
Journal of corporate finance (Amsterdam, Netherlands),
February 2024, 2024-02-00, Letnik:
84
Journal Article
Recenzirano
This paper investigates whether network effects on investment exist and whether firms strategically herd their connected firms. To construct firm networks, we utilize board-interlock networks where ...two firms share at least one common board member and estimate network effects on firms’ investment decisions. Our identification strategy is built on adopting characteristics of the peers of peers as legitimate instrumental variables. Empirical findings confirm significant network effects on firms’ investment and show that firms strategically follow their connected firms with high-quality information.
•Elaborated respectively the influence mechanisms of the microgap and micromotion between the implant and the abutment on implant marginal bone loss in detail.•The relationship between microgap, ...micromotion, microleakage and mechanical damage, and their influences on bone resorption around implant neck are particularly explained.•Some feasible clinical methods to reduce the bone resorption engendered by the microgap and micromotion at the IAI are recommended.
To review the influences and clinical implications of micro-gap and micro-motion of implant-abutment interface on marginal bone loss around the neck of implant.
Literatures were searched based on the following Keywords: implant-abutment interface/implant-abutment connection/implant-abutment conjunction, microgap, micromotion/micromovement, microleakage, and current control methods available. The papers were then screened through titles, abstracts, and full texts.
A total of 83 studies were included in the literature review. Two-piece implant systems are widely used in clinics. However, the production error and masticatory load result in the presence of microgap and micromotion between the implant and the abutment, which directly or indirectly causes microleakage and mechanical damage. Consequently, the degrees of microgap and micromotion further increase, and marginal bone absorption finally occurs. We summarize the influences of microgap and micromotion at the implant-abutment interface on marginal bone loss around the neck of the implant. We also recommend some feasible methods to reduce their effect.
Clinicians and patients should pay more attention to the mechanisms as well as the control methods of microgap and micromotion. To reduce the corresponding detriment to the implant marginal bone, suitable Morse taper or hybrid connection implants and platform switching abutments should be selected, as well as other potential methods.
The emergence of autonomous vehicles (AVs) is expected to revolutionize road transportation in the near future. Although large-scale numerical simulations and small-scale experiments have shown ...promising results, a comprehensive theoretical understanding to smooth traffic flow via AVs is lacking. In this article, from a control-theoretic perspective, we establish analytical results on the controllability, stabilizability, and reachability of a mixed traffic system consisting of human-driven vehicles and AVs in a ring road. We show that the mixed traffic system is not completely controllable, but is stabilizable, indicating that AVs can not only suppress unstable traffic waves but also guide the traffic flow to a higher speed. Accordingly, we establish the maximum traffic speed achievable via controlling AVs. Numerical results show that the traffic speed can be increased by over 6% when there are only 5% AVs. We also design an optimal control strategy for AVs to actively dampen undesirable perturbations. These theoretical findings validate the high potential of AVs to smooth traffic flow.
Due to wide distribution, easy production, and difficult degradation, microplastic pollution has become a new environmental problem that has attracted worldwide attention. However, there is little ...information about the effects of microplastics in soil and their combined pollution with other organic pollutants on crop growth. In this study, we conducted soil culture experiments to evaluate the effects of polyethylene microplastics (PE-MPs) (0.5%, 1%, 2%, 5%, 8% w/w) individual and combined with phenanthrene (100 mg kg−1) on wheat growth for 15 days. Under PE-MPs alone and combined with phenanthrene exposure, dose-dependent toxicities in biomass, shoot height and root length were observed. Over 1% PE-MPs stimulate wheat root elongation. Compared with single phenanthrene treatment, the co-contamination of PE-MPs and phenanthrene reduces the accumulation of phenanthrene in wheat roots and leaves. In the range of 0–5%, the activity of wheat root antioxidant enzymes increases with increasing PE-MP concentration; but both phenanthrene and high concentrations (8%) of PE-MPs cause damage to the antioxidant system in wheat roots. In the presence or absence of phenanthrene, the photosynthetic pigment concentration of wheat leaves shows a dual concentration effect of low promotion and high inhibition under PE-MPs stress. The single pollution of PE-MPs destroys the photosynthetic system of wheat leaves, while the co-contamination of PE-MPs and phenanthrene exacerbates this destruction. Therefore, the co-contamination of PE-MPs and phenanthrene causes greater damage to wheat growth. Our findings can help to evaluate the individual and comprehensive toxicity of microplastics and polycyclic aromatic hydrocarbons to crops.
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•Combined pollution of PE-MPs and phenanthrene exhibits higher toxicity.•PE-MPs stimulate root elongation, but inhibit shoot weight at high concentrations.•The activity of antioxidant enzyme system in roots is increased by PE-MPs.•The effect of PE-MPs on photosynthesis shows low promotion and high inhibition.
Deep learning, a pivotal branch of artificial intelligence, has increasingly influenced the financial domain with its advanced data processing capabilities. This paper introduces Factor-GAN, an ...innovative framework that utilizes Generative Adversarial Networks (GAN) technology for factor investing. Leveraging a comprehensive factor database comprising 70 firm characteristics, Factor-GAN integrates deep learning techniques with the multi-factor pricing model, thereby elevating the precision and stability of investment strategies. To explain the economic mechanisms underlying deep learning, we conduct a subsample analysis of the Chinese stock market. The findings reveal that the deep learning-based pricing model significantly enhances return prediction accuracy and factor investment performance in comparison to linear models. Particularly noteworthy is the superior performance of the long-short portfolio under Factor-GAN, demonstrating an annualized return of 23.52% with a Sharpe ratio of 1.29. During the transition from state-owned enterprises (SOEs) to non-SOEs, our study discerns shifts in factor importance, with liquidity and volatility gaining significance while fundamental indicators diminish. Additionally, A-share listed companies display a heightened emphasis on momentum and growth indicators relative to their dual-listed counterparts. This research holds profound implications for the expansion of explainable artificial intelligence research and the exploration of financial technology applications.
Discharging of the aprotic Li‐O2 battery relies on the O2 reduction reaction (ORR) forming solid Li2O2 in the positive electrode, which is often characterized by a sharp voltage drop (that is, sudden ...death) at the end of discharge, delivering a capacity far below its theoretical promise. Toward unlocking the energy capabilities of Li‐O2 batteries, it is crucial to have a fundamental understanding of the origin of sudden death in terms of reactive sites and transport limitations. Herein, a mechanistic study is presented on a model system of Au|Li2O2|Li+ electrolyte, in which the Au electrode was passivated with a thin Li2O2 film by discharging to the state of sudden death. Direct conductivity measurement of the Li2O2 film and in situ spectroscopic study of ORR using 18O2 for passivation and 16O2 for further discharging provide compelling evidence that ORR (and O2 evolution reaction as well) occurs at the buried interface of Au|Li2O2 and is limited by electron instead of Li+ and O2 transport.
Direct conductivity measurement of an electrodeposited Li2O2 film and an in situ SERS study on the O2 reduction reaction (ORR) using 18O2 for passivation and 16O2 for further discharging unveiled the origin of sudden death of aprotic Li‐O2 batteries. Both ORR and O2 evolution (OER) occur at the buried interface of cathode|Li2O2, and thus the Li‐O2 electrochemistry is limited by electron transport instead of Li+ and O2 transport.
Bacteriophage infection, a pivotal process in microbiology, initiates with the phage's tail recognizing and binding to the bacterial cell surface, which then mediates the injection of viral DNA. ...Although comprehensive studies on the interaction between bacteriophage lambda and its outer membrane receptor, LamB, have provided rich information about the system's biochemical properties, the precise molecular mechanism remains undetermined. This study revealed the high-resolution cryo-electron microscopy (cryo-EM) structures of the bacteriophage lambda tail complexed with its irreversible Shigella sonnei 3070 LamB receptor and the closed central tail fiber. These structures reveal the complex processes that trigger infection and demonstrate a substantial conformational change in the phage lambda tail tip upon LamB binding. Providing detailed structures of bacteriophage lambda infection initiation, this study contributes to the expanding knowledge of lambda-bacterial interaction, which holds significance in the fields of microbiology and therapeutic development.
•Environmental and biological hazard risk were assessed by geostatistics and GIS.•Anthropogenic inputs and fine grained sediments might explain for high enrichment.•Arsenic was defined as main ...pollutant in the Yangtze River estuary.•The contamination degree would be assessed by the combination of heavy metals.
30 samples of eight heavy metals were collected in February 2011 within Yangtze River estuary (YRE). The mean concentrations met the primary standard criteria based on Marine Sediments Quality of China. The spatial distribution showed that a gradient concentration decreased gradually from inner-estuary to river mouth. Anthropogenic inputs might be the main contributor, and fine grained sediments might also aggravate the heavy metal contamination. The assessment results indicated that the YRE was in low risk of contamination caused by every single heavy metal. However, it was in considerable degree of contamination considering combination of all the heavy metals. The toxicities of heavy metals might be elevated when heavy metals were in combination. Arsenic should be of primary concern due to its higher assessment values and the potential of adverse biological effects. And the concentration of As in the YRE had a trend to increase because of anthropogenic activities nearby.
In plants, hyperosmolality stimuli triggers opening of the osmosensitive channels, leading to a rapid downstream signaling cascade initiated by cytosolic calcium concentration elevation. Members of ...the OSCA family in Arabidopsis thaliana, identified as the hyperosmolality-gated calcium-permeable channels, have been suggested to play a key role during the initial phase of hyperosmotic stress response. Here, we report the atomic structure of Arabidopsis OSCA1.2 determined by single-particle cryo-electron microscopy. It contains 11 transmembrane helices and forms a homodimer. It is in an inactivated state, and the pore-lining residues are clearly identified. Its cytosolic domain contains a RNA recognition motif and two unique long helices. The linker between these two helices forms an anchor in the lipid bilayer and may be essential to osmosensing. The structure of AtOSCA1.2 serves as a platform for the study of the mechanism underlying osmotic stress responses and mechanosensing.
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