Macro-ecological patterns in seed removal by animals

This thesis aims to improve our understanding of several long-held ideas concerning seed removal by animals across large-scale gradients. By assembling a database of 13,135 animal-seed interactions across all vertebrate taxa, I provided the first broad test of the idea that large animals ingest large seeds. Surprisingly, I found that the size of ingested seeds was significantly negatively correlated with animal body weight. This negative relationship was driven by large animals, particularly ungulates, ingesting small seeds. The results show that the loss of large animals could have negative effects on the dispersal of small-seeded plants, in addition to the more widely acknowledged impacts on large-seeded plants. Next, I used data for 4008 Australian species to provide the first quantitative analysis of the idea that fleshy fruits are more prevalent towards the tropics. Plants were more likely to bear fleshy fruits at low latitudes, and in regions with warm, wet and stable climates. Fruit type was more strongly affected by conditions during the parts of the year in which they grow than by conditions during the harshest parts of the year, suggesting that some current theories on plant traits may focus on the wrong aspects of climate. Finally, I performed a field study across 25 sites spanning 28 degree of latitude along the east coast of Australia, to provide the first empirical test of the idea that seed predation and seed defense are greater towards the tropics. Contrary to traditional expectations, neither seed predation nor seed physical defence was more intense at low latitudes. In fact, pre-dispersal predation and defence were greater at higher latitudes. My results are consistent with recent findings on latitudinal gradients in herbivory and defences in leaves. My findings cast further doubt on the generality of latitudinal gradients in biotic interactions, and suggest that increased seed/seedling mortality as predicted by the Janzen-Connell hypothesis does not provide a plausible explanation for the greater diversity of tropical ecosystems. My thesis has tested several well-accepted ideas on seed removal by animals, and shown that our understanding of the factors that shape global patterns in biodiversity needs to be reshaped

Capital ratios and the cross-section of bank stock returns: Evidence from Japan

Abstract We propose a market-valued capital ratio as an indicator to gauge the riskiness of banks. In particular, we examine the cross-sectional relation between the market-valued capital ratio and stock returns of listed Japanese banks. It is found that banks with lower market-valued capital ratios have had higher returns on average than banks with higher market-valued capital ratios. However, we show that this negative relation between market-valued capital ratio and average stock returns could essentially be attributed to differences in exposure to risk factors. The market-valued capital ratio appears to proxy for sensitivity to common risk factors in bank stock returns. We also relate the cross-sectional variation in market-valued capital ratios to systematic patterns in relative profitability by showing that low market-valued capital ratio signals persistently poor profitability. Finally, we provide evidence to show that the market-valued capital ratio can indeed serve as a strong predictive indicator for bank's share performance during the financial crisis in the late 1990s, even after controlling for a variety of other traditional risk measures.Market-valued capital ratio BIS capital ratio Cross-section of bank stock returns

Essays on the Dynamic and Cross-Section of Stock Returns

博士（商学）甲第544号3, 175pHitotsubashi University(一橋大学

Style classification and prediction of residential buildings based on machine learning

Architectural style positioning is an important part in the process of residential building design and project planning. However, in practice, due to the complexity and ambiguity of styles, style positioning often relies more on the subjective judgement of the designers and lacks scientificity. This paper proposes a method for the classification and prediction of residential building styles. Through structured interviews and questionnaire surveys on front-line designers and project planners, it refines the key morphological elements and the site economic factors that influence architectural style classification and positioning. Based on machine learning, after analysing the data of 372 newly built real estate projects in Hangzhou, the research finds t|TABE_A_1779728|TABE_A_1779728hat the current real estate styles can generally be divided into 8 categories. Whether it is a curved volume, the shape of the roof and the richness of the tones are the most important morphological variables that differentiate style categories, and the building height is the most important economic factor for style positioning. When using the selected five economic factors as independent variables to train a neural network model and predict the morphological elements and style categories, the average accuracy reaches 77.2%

Bank Competition, Foreign Bank Entry, and Risk-Taking Behavior: Cross Country Evidence

This unique study examines the interactive role of bank competition and foreign bank entry in explaining the risk-taking of banks over the globe. We used cross-country data for the banking sector from 2000 to 2016. Using the pooled regression model and Two-stage Least Squares model (2SLS with Generalized Method of Moments GMM), we document that foreign bank entry decreases the risk-taking behavior of the banks to a certain level and exhibits an inverted U-shaped relation with financial stability. Furthermore, the joint effect of bank competition and foreign bank entry brings financial fragility because host banks tend to make risky investments due to undue competition induced by foreign bank entry. We support the competition–fragility hypothesis when foreign bank entry goes beyond a certain threshold. Our results also suggest that restrictions on bank activities and capital regulation stringency reduce the level of the risk factor. We also applied various robustness tests, which further confirm our mainstream results. Our findings have policy implications for foreign investors and regulatory authorities

Ellagic acid inhibits tumor growth and potentiates the therapeutic efficacy of sorafenib in hepatocellular carcinoma

Background: Sorafenib is a classic molecular targeted drug approved for hepatocellular carcinoma (HCC) therapy. However, a poor response rate and increasing resistance to sorafenib make its therapeutic efficacy suboptimal. Combination treatment with an agent capable of potentiating sorafenib sensitivity may be a promising solution. Aim: The aim of this study was to determine the synergistic effect of ellagic acid (EA), a natural polyphenol, and sorafenib on HCC. Methods: CCK-8, EdU incorporation and colony formation assays were used to study the effect of EA on HCC cell proliferation. Apoptosis was detected by flow cytometry in HCC cells and TUNEL assay in xenograft tumors. Transcriptome analysis was utilized to investigate alterations in signaling pathways with EA treatment. A xenograft mouse model was used to confirm the synergistic effect of sorafenib and EA on HCC tumors in vivo. Results: We found that EA inhibited growth and induced apoptosis in both HCC cells and xenograft tumors. Mechanistically, EA treatment reduced the activation of the MAPK and Akt/mTOR signaling pathways in HCC cells. Furthermore, combined EA and sorafenib treatment further inhibited the MAPK and Akt/mTOR signaling pathways compared to EA or sorafenib alone. EA synergistically potentiated the anticancer activity of sorafenib against HCC both in vitro and in vivo. Conclusion: EA inhibits HCC growth by inducing apoptosis through attenuation of the MAPK and Akt/mTOR signaling pathways. EA potentiates the response of HCC tumors to sorafenib both in vitro and in vivo, an effect that may be attributed to further inhibition of the MAPK and Akt/mTOR signaling pathways. These results suggest that EA is an effective adjuvant option for sorafenib therapy

A Facile Synthesis of Hexagonal Spinel λ-MnO2 Ion-Sieves for Highly Selective Li+ Adsorption

Ion-sieves are a class of green adsorbent for extraction Li+ from salt lakes. Here, we propose a facile synthesis of hexagonal spinel LiMn2O4 (LMO) precursor under mild condition which was first prepared via a modified one-pot reduction hydrothermal method using KMnO4 and ethanol. Subsequently, the stable spinel structured λ-MnO2 (HMO) were prepared by acidification of LMO. The as-prepared HMO shows a unique hexagonal shape and can be used for rapid adsorption-desorption process for Li+ adsorption. It was found that Li+ adsorption capacity of HMO was 24.7 mg·g−1 in Li+ solution and the HMO also has a stable structure with manganese dissolution loss ratio of 3.9% during desorption process. Moreover, the lithium selectivity ( α Mg Li ) reaches to 1.35 × 103 in brine and the distribution coefficients ( K d ) of Li+ is much greater than that of Mg2+. The results implied that HMO can be used in extract lithium from brine or seawater containing high ratio of magnesium and lithium

Data from: Species richness and phylogenetic diversity of seed plants across vegetation zones of Mount Kenya, East Africa

Mount Kenya is of ecological importance in tropical east Africa due to the dramatic gradient in vegetation types that can be observed from low to high elevation zones. However, species richness and phylogenetic diversity of this mountain have not been well studied. Here, we surveyed distribution patterns for a total of 1,335 seed plants of this mountain and calculated species richness and phylogenetic diversity across seven vegetation zones. We also measured phylogenetic structure using the net relatedness index (NRI) and the nearest species index (NTI). Our results show that lower montane wet forest has the highest level of species richness, density, and phylogenetic diversity of woody plants, while lower montane dry forest has the highest level of species richness, density, and phylogenetic diversity in herbaceous plants. In total plants, NRI and NTI of four forest zones were smaller than three alpine zones. In woody plants, lower montane wet forest and upper montane forest have overdispersed phylogenetic structures. In herbaceous plants, NRI of Afro‐alpine zone and nival zone are smaller than those of bamboo zone, upper montane forest, and heath zone. We suggest that compared to open dry forest, humid forest has fewer herbaceous plants because of the closed canopy of woody plants. Woody plants may have climate‐dominated niches, whereas herbaceous plants may have edaphic and microhabitat‐dominated niches. We also proposed lower and upper montane forests with high species richness or overdispersed phylogenetic structures as the priority areas in conservation of Mount Kenya and other high mountains in the Eastern Afro‐montane biodiversity hotspot regions

Preparation and Properties of Biobased, Cationic, Waterborne Polyurethanes Dispersions from Castor Oil and Poly (Caprolactone) Diol

Biobased cationic waterborne polyurethanes (WPUs) were prepared using isophorone diisocyanate (IPDI), N-methyl diethanolamine (N-MDEA), polycaprolactone (PCL) diol, hydrochlotic acid (HCl), and 1,4-butanediol (BDO). To improve the mechanical performance and adhesive strength of the waterborne polyurethane films, different amounts of castor oil (CO) acting as a cross-linking agent were incorporated in the polyurethane structure. The structures of the waterborne polyurethanes were assessed by Fourier-transform infrared spectroscopy (FTIR). The combination of CO had a positive effect on the dispersion and stability properties of WPUs. WPUs containing higher content of CO demonstrated a remarkable enhancement in homogeneity among particles. The stable aqueous dispersion was obtained even when N-MDEA loading was as low as 3.2 wt%; a bonus of this low hydrophilic moiety was the excellent adhesive strength, whose T-peel strength could reach up to 36.8 N/25 mm, about 114% higher than that of WPU (17.2 N/25 mm) without any CO content. The elongation at break of CO7.40%-WPU was 391%. In addition, the fracture mechanism of the waterborne polyurethane films transformed from the brittle failure to the ductile fracture. The experiment results showed the CO-modified WPUs displayed excellent film-forming property, flexibility, and adhesion, which can be employed for constructing the eco-friendly, biodegradable, cationic, waterborne polyurethanes

Gut microbiota and microbiota-derived metabolites in cardiovascular diseases.

AbstractCardiovascular diseases, including heart failure, coronary artery disease, atherosclerosis, aneurysm, thrombosis, and hypertension, are a great economic burden and threat to human health and are the major cause of death worldwide. Recently, researchers have begun to appreciate the role of microbial ecosystems within the human body in contributing to metabolic and cardiovascular disorders. Accumulating evidence has demonstrated that the gut microbiota is closely associated with the occurrence and development of cardiovascular diseases. The gut microbiota functions as an endocrine organ that secretes bioactive metabolites that participate in the maintenance of cardiovascular homeostasis, and their dysfunction can directly influence the progression of cardiovascular disease. This review summarizes the current literature demonstrating the role of the gut microbiota in the development of cardiovascular diseases. We also highlight the mechanism by which well-documented gut microbiota-derived metabolites, especially trimethylamine N-oxide, short-chain fatty acids, and phenylacetylglutamine, promote or inhibit the pathogenesis of cardiovascular diseases. We also discuss the therapeutic potential of altering the gut microbiota and microbiota-derived metabolites to improve or prevent cardiovascular diseases