Search

This study proposed an innovative automated approach to differentiation of the vocabulary proficiency of Chinese speakers. A robust K-means algorithm was designed to compare the oral proficiency between L1 and L2 Chinese speakers regarding lexical richness and how relatively effective the various lexical measures were in performing the differentiation task. Eighteen lexical richness measures were surveyed and compared using the clustering analysis. The effectiveness of each selected measure as well as an overall evaluation of all the measures for the concerned differentiation tasks were comprehensively calibrated. The results demonstrate that, while the L1 versus L2 group difference in lexical richness was observed with statistical significance for each of the chosen measures, the clustering and membership prediction accuracy of individual speakers varied greatly from one measure to another. The implication is that a more fully defined metric of lexical richness is still a worthwhile endeavor for language proficiency assessment, with optimal directions for such endeavors discussed in the concluding remarks.

While the public sector is traditionally the sole provider for much of infrastructure, the pendulum is shifting in light of the enormous investment gap. Across the Global South, public utilities and planning agencies are engaging with the private sector to help bridge the gap. What are the key patterns of private participation in infrastructure (PPI) across countries in the Global South? What macro factors underscore such private participation? These research questions motivate this paper, focusing on five infrastructure sectors across the Global South and its regions. Following a historical synthesis of the changing balance of public and private provision, the paper outlines recent patterns of PPI. Drawing from a World Bank database, a regression analysis includes key macro-level predictors for private sector financing, for both the number of projects and stock of investment. Key results point to the importance of market size and in turn the potential for risk diversification, as well as a set of governance factors underlining investor confidence and stable environment. [ABSTRACT FROM AUTHOR]

The self‐assembly of the π‐conjugated 1,4‐di(1H‐imidazol‐1‐yl)benzene (dib) and 4,4′‐di(1H‐imidazol‐1‐yl)‐1,1′‐biphenyl (dibp) ligands together with 4′‐(3,4‐ dicarboxylphenyloxy)‐4‐biphenylcarboxylic acid (H3L) reacts with metal Zn (II) salts to construct two new coordination polymers (CPs), namely [Zn (dib)(HL)(H2O)] (1) and [Zn (dibp)(HL)] (2). Fluorescence measurements reveal that 1 and 2 could display a highly sensitive fluorescence response toward Hg2+ and nitrofurazone (NFZ). Fluorescence investigations suggest that 1 and 2 are promising multi‐responsive sensing materials for detecting Hg2+ and NFZ through fluorescence quenching (turn‐off). The limits of detection toward Hg2+ ions are 0.221 μM and 0.124 μM, while the limits of detection toward NFZ are 0.757 μM and 0.960 for 1 and 2, respectively. Interestingly, these Hg2+ and NFZ selective sensing processes can even be completed by the reusable CPs detected by the naked eyes. Hirshfeld surfaces and fingerprint plots are extensively used to investigate intermolecular interactions, which play a crucial role in creating diverse supramolecular designs that can be compared. [ABSTRACT FROM AUTHOR]

Recognizing the importance of incorporating different risk measures in the portfolio management model, this paper examines the dynamic mean-risk portfolio optimization problem using both variance and value at risk (VaR) as risk measures. By employing the martingale approach and integrating the quantile optimization technique, we provide a solution framework for this problem. We demonstrate that, under a general market setting, the optimal terminal wealth may exhibit different patterns. When the market parameters are deterministic, we derive the closed-form solution for this problem. Examples are provided to illustrate the solution procedure of our method and demonstrate the benefits of our dynamic portfolio model compared to its static counterpart. [ABSTRACT FROM AUTHOR]

Simple Summary: Insects have special receptors called RDL that regulate the effects of a neurotransmitter GABA in their nervous system. Interestingly, these receptors are also the main targets of many insecticides used to control pests. We used fruit flies with different variants of the Rdl gene and tested four new types of meta-diamide and isoxazoline insecticides. The results showed that some mutations made the flies less sensitive to certain insecticides, while another mutation made the flies super resistant to all of the insecticides tested. Using computer simulations, we explored how these mutations might be affecting the insecticides' ability to attach. We found that specific areas between parts of the receptor seem to be important for these new insecticides to work. This helps us understand how insects can resist these insecticides and might lead to better ways to control pests in the future. Ionotropic γ-aminobutyric acid (GABA) receptors in insects, specifically those composed of the RDL (resistant to dieldrin) subunit, serve as important targets for commonly used synthetic insecticides. These insecticides belong to various chemical classes, such as phenylpyrazoles, cyclodienes, meta-diamides, and isoxazolines, with the latter two potentially binding to the transmembrane inter-subunit pocket. However, the specific amino acid residues that contribute to the high sensitivity of insect RDL receptors to these novel insecticides remain elusive. In this study, we investigated the susceptibility of seven distinct Drosophila melanogaster Rdl point mutants against four meta-diamide and isoxazoline insecticides: isocycloseram, fluxametamide, fluralaner, and broflanilide. Our findings indicate that, despite exhibiting increased sensitivity to fluralaner in vitro, the RdlI276C mutant showed resistance to isocycloseram and fluxametamide. Similarly, the double-points mutant RdlI276F+G279S also showed decreased sensitivity to the tested isoxazolines. On the other hand, the RdlG335M mutant displayed high levels of resistance to all tested insecticides. Molecular modeling and docking simulations further supported these findings, highlighting similar binding poses for these insecticides. In summary, our research provides robust in vivo evidence supporting the idea that the inter-subunit amino acids within transmembrane M1 and M3 domains form the binding site crucial for meta-diamide and isoxazoline insecticide interactions. This study highlights the complex interplay between mutations and insecticide susceptibility, paving the way for more targeted pest control strategies. [ABSTRACT FROM AUTHOR]

AbstractChina’s rapid urbanization has been driven by large-scale internal migrants, and it is worth exploring the impact of internal migrants on local labor markets. Based on data from China’s population census, population sample survey and urban household survey, this study empirically tests the wage premium effect of internal migrants on local labor, and further investigates the mechanisms of wage premium from skill complementarity, as well as the policy adjustment effect of labor market reforms. The results show that: (1) The wage premium effect originating from migrants is significant, and gradually decreases over time and with the increase of local worker wages. (2) The wage premium effect is more prominent in large cities, mega and super-sized cities, which can be explained by economic agglomeration and division of labor induced by skill complementarities. (3) Labor market-oriented reforms contribute to enhancing the wage premium effect, with marginal effects of 3.71% and 3.64%. [ABSTRACT FROM AUTHOR]

A tunable multiband terahertz metamaterial absorber, based on vanadium dioxide (VO2), is demonstrated. The absorber comprises a three-layer metal–insulator–metal (MIM) configuration with a split ring and slots of VO2 on the uppermost layer, a middle dielectric substrate based on silicon dioxide (SiO2), and a gold reflector on the back. The simulation results indicate that, when VO2 is in the metallic state, the proposed metamaterial exhibits nearly perfect absorption at six distinct frequencies. The design achieves an average absorption of 98.2%. The absorptivity of the metamaterial can be dynamically tuned from 4% to 100% by varying the temperature-controlled conductivity of VO2. The proposed metamaterial absorber exhibits the advantages of polarization insensitivity and maintains its absorption over 80% under different incident angle conditions. The underlying physical mechanism of absorption is explained through impedance matching theory, interference theory, and the distribution of electric fields. The ability to achieve multiband absorption with tunable characteristics makes the proposed absorber a promising candidate for applications in terahertz sensing, imaging, communication, and detection. The polarization insensitivity further enhances its practicality in various scenarios, allowing for versatile and reliable performance in terahertz systems. [ABSTRACT FROM AUTHOR]

Abstract Background Cystic echinococcosis (CE) is a human and animal health problem in many endemic areas worldwide. It is considered a neglected zoonotic disease caused by the larval form (hydatid cyst) of Echinococcus spp. tapeworm. There are limited studies on echinococcosis in Pakistan. Methods A cross-sectional survey was conducted to find out recent knowledge, attitudes and practices on the occurrence of cystic echinococcosis in butchers and dog owners in both urban and rural areas of Rawalpindi/Islamabad regions, Pakistan. The quantitative data was collected in the form of questionnaires to investigate the knowledge and awareness of CE among community members and their routine practices that were behind the factors involved in hydatid cyst infection. The practices and infrastructure of abattoirs/butcher shops and their role in transmission of cystic echinococcosis were also evaluated in the present study. Results The participants involved in the study were dog owners and people who kept animals. A total of 400 people were interviewed and 289 questionnaires were received. The results showed that only 4.1% of people have heard about the disease, and 58.1% were closely associated with dogs. Sixty-three percent of dogs in study area were consuming uncooked organs (e.g. liver, lung, etc.) of slaughtered animals, while 100% of dogs at butcher shops were consuming uncooked organs. Home slaughtering was common in 20.06%. Among butchers, 32.3% had heard about zoonoses and 7.61% knew about CE. The statistical analysis showed that there was highly significant difference (P < 0.05) among most of the practices that were associated with the prevalence of CE. Conclusions It was concluded from the present study that, the knowledge and awareness of CE among people of Rawalpindi/Islamabad were low. Because of dogs and poor knowledge of CE among community members and butchers, the transmission of echinococcosis is facilitated. Therefore, there is urgent need to strengthen awareness and health education among people, as well as proper practices related to the CE not only in the study area, but also in other areas of Pakistan.