Data-Driven Recommendations for Establishing Threshold Values for the NIS Trend Indicator in the Mediterranean Sea

In the present work, we analysed time series data on the introduction of new non-indigenous species (NIS) in the Mediterranean between 1970 and 2017, aiming to arrive at recommendations concerning the reference period and provisional threshold values for the NIS trend indicator. We employed regression analysis and breakpoint structural analysis. Our results confirm earlier findings that the reference conditions differ for the four Mediterranean subregions, and support a shortening of the reporting cycle from six to three years, with a two-year time lag for the ensuing assessment. Excluding Lessepsian fishes and parasites, the reference period, defined as the most recent time segment with stable mean new NIS values, was estimated as 1997–2017 for the eastern Mediterranean, 2012–2017 for the central Mediterranean, 2000–2017 for the Adriatic and 1970–2017 for the western Mediterranean. These findings are interpreted primarily on the basis of a basin scale temperature regime shift in the late 1990s, shifts in driving forces such as shellfish culture, and as a result of intensified research efforts and citizen scientist initiatives targeting NIS in the last decade. The threshold values, i.e., the three-year average new NIS values during the reference period, are indicative and will ultimately depend on the choice of species and pathways to be used in the calculations. This is discussed through the prism of target setting in alignment with specific management objectives.

Influence of Topographic Conditions on Teak Growth Performance in Mountainous Landscapes of Lao PDR

Teak is a globally valuable hardwood tree species, as its growth performance is important for timber productivity. The purpose of this study was to establish an effective management system for teak plantations in the Lao PDR. Using diameter at breast height (DBH) and height growth as significant indicators of growth performance, we investigated the relationship between tree growth curve parameters of teak and topographic conditions. Stem analysis data for 81 sample trees (three trees selected in canopy trees with predominant height in each plot) were examined for growth performance using the Mitscherlich growth function. The results of Spearman’s partial rank correlation indicated that the upper limits of DBH and tree height growth had significant negative correlations with the slope gradient and stand density. The curvature of DBH and tree height growth curves showed significant positive correlations with the slope form. Moreover, the elevation and slope gradient showed significant negative correlations with the curvature of tree height growth curve. However, the time lag of DBH growth showed a significant negative correlation with the slope position, while the slope gradient was positively correlated with the time lag of tree height growth. These results suggest that teak planted at lower slopes has faster growth rates and that there is an interaction with the gentle concave slope of this area.

Evaluating Research Trends from Journal Paper Metadata, Considering the Research Publication Latency

Investigating the research trends within a scientific domain by analyzing semantic information extracted from scientific journals has been a topic of interest in the natural language processing (NLP) field. A research trend evaluation is generally based on the time evolution of the term occurrence or the term topic, but it neglects an important aspect—research publication latency. The average time lag between the research and its publication may vary from one month to more than one year, and it is a characteristic that may have significant impact when assessing research trends, mainly for rapidly evolving scientific areas. To cope with this problem, the present paper is the first work that explicitly considers research publication latency as a parameter in the trend evaluation process. Consequently, we provide a new trend detection methodology that mixes auto-ARIMA prediction with Mann–Kendall trend evaluations. The experimental results in an electronic design automation case study prove the viability of our approach.

Tunning CO2 Separation Performance of Ionic Liquids through Asymmetric Anions

This work aims to explore the gas permeation performance of two newly-designed ionic liquids, [C2mim][CF3BF3] and [C2mim][CF3SO2C(CN)2], in supported ionic liquid membranes (SILM) configuration, as another effort to provide an overall insight on the gas permeation performance of functionalized-ionic liquids with the [C2mim]+ cation. [C2mim][CF3BF3] and [C2mim][CF3SO2C(CN)2] single gas separation performance towards CO2, N2, and CH4 at T = 293 K and T = 308 K were measured using the time-lag method. Assessing the CO2 permeation results, [C2mim][CF3BF3] showed an undermined value of 710 Barrer at 293.15 K and 1 bar of feed pressure when compared to [C2mim][BF4], whereas for the [C2mim][CF3SO2C(CN)2] IL an unexpected CO2 permeability of 1095 Barrer was attained at the same experimental conditions, overcoming the results for the remaining ILs used for comparison. The prepared membranes exhibited diverse permselectivities, varying from 16.9 to 22.2 for CO2/CH4 and 37.0 to 44.4 for CO2/N2 gas pairs. The thermophysical properties of the [C2mim][CF3BF3] and [C2mim][CF3SO2C(CN)2] ILs were also determined in the range of T = 293.15 K up to T = 353.15 K at atmospheric pressure and compared with those for other ILs with the same cation and anion’s with similar chemical moieties.

Optimization and Evaluation of SO2 Emissions Based on WRF-Chem and 3DVAR Data Assimilation

Emission inventories are important for modeling studies and policy-making, but the traditional “bottom-up” emission inventories are often outdated with a time lag, mainly due to the lack of accurate and timely statistics. In this study, we developed a “top-down” approach to optimize the emission inventory of sulfur dioxide (SO2) using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) and a three-dimensional variational (3DVAR) system. The observed hourly surface SO2 concentrations from the China National Environmental Monitoring Center were assimilated and used to estimate the gridded concentration forecast errors of WRF-Chem. The concentration forecast errors were then converted to the emission errors by assuming a linear response from SO2 emission to concentration by grids. To eliminate the effects of modelling errors from aspects other than emissions, a strict data-screening process was conducted. Using the Multi-Resolution Emission Inventory for China (MEIC) 2010 as the a priori emission, the emission inventory for October 2015 over Mainland China was optimized. Two forecast experiments were conducted to evaluate the performance of the SO2 forecast by using the a priori (control experiment) and optimized emissions (optimized emission experiment). The results showed that the forecasts with optimized emissions typically outperformed the forecasts with 2010 a priori emissions in terms of the accuracy of the spatial and temporal distributions. Compared with the control experiment, the bias and root-mean-squared error (RMSE) of the optimized emission experiment decreased by 71.2% and 25.9%, and the correlation coefficients increased by 50.0%. The improvements in Southern China were more significant than those in Northern China. For the Sichuan Basin, Yangtze River Delta, and Pearl River Delta, the bias and RMSEs decreased by 76.4–94.2% and 29.0–45.7%, respectively, and the correlation coefficients increased by 23.5–53.4%. This SO2 emission optimization methodology is computationally cost-effective.

Problems seeded in the past: lagged effects of historical land-use changes can cause an extinction debt in long-lived species due to movement limitation

Context Land-use change is one of the main threats to biodiversity on the global scale. Legacy effects of historical land-use changes may affect population dynamics of long-lived species, but they are difficult to evaluate through observational studies alone. We present here an interdisciplinary modelling approach as an alternative to address this problem in landscape ecology. Objectives Assess effects of agricultural abandonment and anthropisation on the population dynamics of long-lived species. Specifically, we evaluated: (a) how changes in movement patterns caused by land-use change might impact population dynamics; (b) time-lag responses of demographic variables in relation to land-use changes. Methods We applied an individual-based and spatial-explicit simulation model of the spur-tighed tortoise (Testudo graeca), an endangered species, to sequences of real-world landscape changes representing agricultural abandonment and anthropisation at the local scale. We analysed different demographic variables and compared an “impact scenario” (i.e., historical land-use changes) with a “control scenario” (no land-use changes). Results While agricultural abandonment did not lead to relevant changes in demographic variables, anthropisation negatively affected the reproductive rate, population density and the extinction probability with time-lag responses of 20, 30 and 130 years, respectively, and caused an extinction debt of 22%. Conclusions We provide an understanding of how changes in animal movement driven by land-use changes can translate into lagged impacts on demography and, ultimately, on population viability. Implementation of proactive mitigation management are needed to promote landscape connectivity, especially for long-lived species for which first signatures of an extinction debt may arise only after decades.

Frequency dependence on polarization switching measurement in ferroelectric capacitors

Ferroelectric hysteresis loop measurement under high driving frequency generally faces great challenges. Parasitic factors in testing circuits such as leakage current and RC delay could result in abnormal hysteresis loops with erroneous remnant polarization (P r) and coercive field (E c). In this study, positive-up-negative-down (PUND) measurement under a wide frequency range was performed on a 10-nm thick Hf0.5Zr0.5O2 ferroelectric film. Detailed analysis on the leakage current and RC delay was conducted as the polarization switching occurs in the FE capacitor. After considering the time lag caused by RC delay, reasonable calibration of current response over the voltage pulse stimulus was employed in the integral of polarization current over time. In such a method, rational P–V loops measured at high frequencies (>1 MHz) was successfully achieved. This work provides a comprehensive understanding on the effect of parasitic factors on the polarization switching behavior of FE films.