Regulation Mechanism of Exogenous Brassinolide on Bulbil Formation and Development in Pinellia ternata

The bulbil is the propagative organ of the P. ternata, which has a great effect on the yield of P. ternata. It is well known that plant hormones play important roles in bulbil formation and development. However, there is not clear about brassinolide (BR) regulation on bulbil formation and development. In this study, we revealed the effects of BR and BR biosynthesis inhibitors (propiconazole, Pcz) application on the histological observation, starch and sucrose metabolism, photosynthesis pathway, and hormone signaling pathway of P. ternata. The results showed that BR treatment reduced starch catabolism to maltodextrin and maltose in bulbil by decreasing BAM and ISA genes expression and increased cellulose catabolism to D-glucose in bulbil by enhancing edg and BGL genes expression. BR treatment enhanced the photosynthetic pigment content and potential maximum photosynthetic capacity and improved the photoprotection ability of P. ternata by increasing the dissipation of excess light energy to heat, thus reduced the photodamage in the PSII center. BR treatment increased the GA and BR content in bulbil of P. ternata, and decreased the ABA content in bulbil of P. ternata. Pcz treatment increased the level of GA, SL, ABA, and IAA in bulbil of P. ternata. BR regulated the signal transduction of BR, IAA, and ABA to regulate the formation and development of bulbil in P. ternata. These results provide molecular insight into BR regulation on bulbil formation and development.

Application of Risk Analysis in the Screening of Flood Disaster Hot Spots and Adaptation Strategies

In recent years, Taiwan has established a sound flood control foundation in terms of river management. Due to climate change and land development, surface runoff has increased. In addition, the functions of flood control engineering facilities have their limits. Surface runoff cannot be fully absorbed by rivers, and frequent floods still occur in some areas. According to the characteristics of water flowing along the terrain to low-lying land, the terrain features can be used to find out the hot areas prone to flooding and the appropriate location of flood storage space for improving flooding. On the basis of the natural terrain environment, the disaster risk framework is used to manage environmental complexity, and to carry out research on flood warning and governance decision-making systems, so that human beings can coexist with the uncertainty of flood risk. In this study, the Zhuoshuixi Basin was used as the sample area, the SCS-CN method was used to analyze the excess runoff, and the risk concept was used to establish a flood evaluation model. In addition, through the changes in land use, the SCS-CN method estimates the difference of potential maximum retention, quantifies the variation of excess rainfall in each watershed division, and uses the digital elevation model to calculate the depression site to analyze the relationship between the difference of potential maximum retention and the depression space of the watershed. The results show that the adaptation strategy for high-risk flooded areas should be strengthened, and areas with large water storage space and a small potential maximum retention difference can be the best location for offsite compensation.

Price Reversals After Extreme Price Shocks: Impact of Earnings Information With Time Series Evidence From Emerging Market

The purpose of the article is to analyze the relevance of earnings fundamentals in predicting extreme price reversals of an emerging stock market. We collect monthly price data on six sector indices from Bombay Stock Exchange (BSE) of India for the period 2004–2019. The research decomposes industry stock returns into Potential Maximum Gains (PMG) and Potential Maximum Losses (PML) with price extremes at first and then tests price reversal behavior using Generalized AutoRegressive Conditional Heteroskedasticity (GARCH) and vector autoregressive (VAR) models. The study finds symmetry between PMG and PML in the banking, realty, and oil sectors, while the asymmetric reversal behavior is noted in the automobiles and capital goods industries. The presence of industry fundamentals in the models estimating the reversal behavior of share prices enhances their predictive power, which suggests the significance of value strategies in making gains from extreme price variations. The price reversal behavior is sector specific and found inconsistent in emerging market. Hence, the investors cannot overlook the relevance of the industry characteristics and earnings fundamentals while predicting the stock price behavior in emerging markets.

On extreme value theory in the presence of technical trend: pre and post Covid-19 analysis of cryptocurrency markets

Purpose Research on price extremes and overreactions as potential violations of market efficiency has a long tradition in investment literature. Arguably, very few studies to date have addressed this issue in cryptocurrencies trading. The purpose of this paper is to consider the extreme value modelling for forecasting COVID-19 effects on cryptocoin markets. Additionally, this paper examines the importance of technical trading indicators in predicting the extreme price behaviour of cryptocurrencies. Design/methodology/approach This paper decomposes the daily-time series returns of four cryptocurrency returns into potential maximum gains (PMGs) and potential maximum losses (PMLs) at first and then tests their lead–lag relations under an econometric framework. This paper also investigates the non-random properties of cryptocoins by computing the incremental explanatory power of PML–PMG modelling with technical trading indicators controlled. Besides, this paper executes an event study to identify significant changes caused by COVID-19-related events, which is capable of analysing the cryptocoin market overreactions. Findings The findings of this paper produce the evidence of both market overreactions and trend persistence in the potential gains and losses from coins trading. Extreme price behaviour explains volatility and price trends in crypto markets before and after the outbreak of a pandemic that substantiate the non-random walk behaviour of crypto returns. The presence of technical trading indicators as control variables in the extreme value regressions significantly improves the predictive power of models. COVID-19 crisis affects the market efficiency of cryptocurrencies that improves the usefulness of extreme value predictions with technical analysis. Research limitations/implications This paper strongly supports for the robustness of technical trading strategies in cryptocurrency markets. However, the “beast is moving quick” and uncertainty as to the new normalcy about the post-COVID-19 world puts constraint on making best predictions. Practical implications The paper contributes substantially to our understanding of the pricing efficiency of cryptocurrency markets after the COVID-19 outbreak. The findings of continuing return predictability and price volatility during COVID-19 show that profitable investment opportunities for cryptocoin traders are prevailing in pandemic times. Originality/value The paper is unique to understand extreme return reversals behaviour of cryptocurrency markets regarding events related to COVID-19 breakout.

Sensitivity analysis of a simplified precipitation-runoff model to estimate water availability in Southern Portuguese watersheds

The water availability estimation in large regions is a relevant procedure to define broad water resources management policies but may prove difficult due to the lack of data and uncertainty to related regional hydrological and hydrogeological characterization. BALSEQ, a daily sequential water budget model, was applied in a set of twenty-two watersheds in southern Portugal, aiming to understand the possible relations between the model parameters and watershed characteristics that may allow assembling calibration functions for non-monitored watersheds. A sensitivity analysis was conducted by comparing BALSEQ results with measured surface flow, focusing specifically on the fraction of the potential maximum retention (φ) and the maximum amount of water available in the soil for evapotranspiration (AGUT) parameters and the underlying hydrogeological conceptual model that ultimately controls the surface-groundwater interactions. The overall results did not allow to identify clear relations that permit extrapolation to other regions without data as the sensitivity analysis procedures returned similar results for wide intervals of parameters for the majority of watersheds. The results confirmed that the groundwater discharge is an important component for the total measured surface flow and that the φ parameter should not be overlooked when calculating direct runoff. Poor adjustments between the model results and measured flow were observed in watersheds with a low Surface flow – Rainfall ratio.

A Modified Distributed CN-VSA Method for Mapping of the Seasonally Variable Source Areas

Many watershed models employ the Soil Conservation Service Curve Number (SCS-CN) approach for runoff simulation based on soil and land use information. These models implicitly assume that runoff is generated by the Hortonian process and; therefore, cannot correctly account for the effects of topography, variable source area (VSA) and/or soil moisture distribution in a watershed. This paper presents a new distributed CN-VSA method that is based on the SCS-CN approach to estimate runoff amount and uses the topographic wetness index (TWI) to distribute the runoff-generating areas within the watershed spatially. The size of the saturated-watershed areas and their spatial locations are simulated by assuming an average annual value of potential maximum retention. However, the literature indicates significant seasonal variation in potential maximum retention which can considerably effect water balance and amount of nonpoint source pollution. This paper focuses on developing a modified distributed CN-VSA method that accounts for the seasonal changes in the potential maximum retention. The results indicate that the modified distributed CN-VSA approach is better than distributed CN-VSA to simulate runoff amount and spatial distribution of runoff-generating areas. Overall, the study results are significant for improved understanding of hydrological response of watershed where seasonal factors describe the potential maximum retention, and, thus, saturation excess runoff generation in the watershed.

Development of a High-Throughput Method to Study the Inhibitory Effect of Phytochemicals on Trimethylamine Formation

Choline is metabolized by the gut microbiota into trimethylamine (TMA), the precursor of pro-atherosclerotic molecule trimethylamine N-oxide (TMAO). A reduction in TMA formation has shown cardioprotective effects, and some phytochemicals may reduce TMA formation. This study aimed to develop an optimized, high-throughput anaerobic fermentation methodology to study the inhibition of choline microbial metabolism into TMA by phenolic compounds with healthy human fecal starter. Optimal fermentation conditions were: 20% fecal slurry (1:10 in PBS), 100 µM choline, and 12 h fermentation. Additionally, 10 mM of 3,3-dimethyl-1-butanol (DMB) was defined as a positive TMA production inhibitor, achieving a ~50% reduction in TMA production. Gallic acid and chlorogenic acid reported higher TMA inhibitory potential (maximum of 80–90% TMA production inhibition), with IC50 around 5 mM. Neither DMB nor gallic acid or chlorogenic acid reduced TMA production through cytotoxic effects, indicating mechanisms such as altered TMA-lyase activity or expression.

Development of a High Throughput Method to Study the Inhibitory Effect of Phytochemicals on Trimethylamine Formation

Choline is metabolized by the gut microbiota into trimethylamine (TMA), the precursor of pro-atherosclerotic molecule trimethylamine N-oxide (TMAO). Reduction of TMA formation has been shown to provide to cardioprotective effects, and some phytochemicals may produce such reduction. This study aimed to develop an optimized, high-throughput anaerobic fermentation methodology to study inhibition of choline microbial metabolism into TMA by phenolic compounds with healthy human fecal starter. Optimal fermentation conditions were: 20 % fecal slurry (1:10 in PBS), 100 M choline, and 12 h fermentation. Also, 10 mM of 3,3-dimethyl-1-butanol (DMB) was defined as a positive TMA production inhibitor, achieving a ~50 % reduction in TMA production. Gallic acid and chlorogenic acid reported higher TMA inhibitory potential (maximum of 80 -90 % in. TMA production inhibition), with IC50 around 5 mM. Nor DMB neither gallic acid and chlorogenic acid reduced TMA production through cytotoxic effects, indicating mechanisms such as altered TMA lyase activity or expression.

Influence of a small and maximum lake and wetland extent on the simulated West African monsoon precipitation during the mid-Holocene

<p>During the mid-Holocene, an expansion of vegetation, lakes and wetlands over North Africa reinforced the West African monsoon precipitation increase that was initiated by changes in the orbital forcing. Sedimentary records reflect these surface changes, however, they provide only limited spatial and temporal information about the size and distribution of mid-Holocene lakes and wetlands. Previous simulation studies that investigated the influence of mid-Holocene lakes and wetlands on the West African monsoon precipitation, prescribed either a small lake and wetland extent or focusing on mega-lakes only. In contrast to these simulation studies, we investigate the<strong> </strong>range of simulated West African monsoon precipitation changes caused by a small and a potential maximum lake and wetland extent during the mid-Holocene.</p><p>Therefore, four mid-Holocene sensitivity experiments are conducted using the atmosphere model ICON-A and the land model JSBACH4 at 160 km resolution. The simulations have a 30-year evaluation period and only differ in their lake and wetland extent over North Africa: (1) pre-industrial lakes, (2) small lake extent, (3) maximum lake extent and (4) maximum wetland extent. The small lake extent is given by the reconstruction map of Hoelzmann et al. (1998) and the potential maximum lake and wetland extent is given by a model derived map of Tegen et al. (2002).</p><p>The simulation results reveal that the maximum lake extent shifts the Sahel precipitation threshold (> 200 mm/year) about 3 ° further northward than the small lake extent. The major precipitation differences between the small and maximum lake extent results from the lakes over the West Sahara. Additionally, the maximum wetland extent causes a stronger West African monsoon precipitation increase than the equally large maximum lake extent, particularly at higher latitudes.</p>

Evaluation of Sediment Yield and Risk Management of Sediment Disaster With the Natural Resources Conservation Service-Curve Number Method

Subtropical areas are often struck by typhoons. The sediment disasters that accompany typhoons severely affect the environment. However, sediment yield (SY) data usually lack integrity. This study used long-term daily river discharge and SY data to establish a runoff–SY rating curve (Q–Qs rating curve) and used it to estimate the SY of typhoon events. In addition, based on the curve number, this study analyzed the relationship between the potential maximum retention (S) and SY; the results showed that different amounts of cumulative rainfall correspond to different S–SY functions; thus, the potential maximum erosion (A) of the catchment area could be estimated using this characteristic. For a sediment management strategy, this study took subdivisions as a unit and incorporated the potential maximum erosion (A) and slope to establish a map indicating the spatial distribution of sediment disaster risks. To determine the priority areas for management, the relationship between the cumulative number of subdivisions and landslide rate could be used to determine the areas with high potential, which can serve as a reference for related management research.