Adult Repellency and Larvicidal Activity of Five Plant Essential Oils Against Mosquitoes

The larvicidal activity and repellency of 5 plant essential oils—thyme oil, catnip oil, amyris oil, eucalyptus oil, and cinnamon oil—were tested against 3 mosquito species: Aedes albopictus, Ae. aegypti, and Culex pipiens pallens. Larvicidal activity of these essentials oils was evaluated in the laboratory against 4th instars of each of the 3 mosquito species, and amyris oil demonstrated the greatest inhibitory effect with LC50 values in 24 h of 58 µg/ml (LC90  =  72 µg/ml) for Ae. aegypti, 78 µg/ml (LC90  =  130 µg/ml) for Ae. albopictus, and 77 µg/ml (LC90  =  123 µg/ml) for Cx. p. pallens. The topical repellency of these selected essential oils and deet against laboratory-reared female blood-starved Ae. albopictus was examined. Catnip oil seemed to be the most effective and provided 6-h protection at both concentrations tested (23 and 468 µg/cm2). Thyme oil had the highest effectiveness in repelling this species, but the repellency duration was only 2 h. The applications using these natural product essential oils in mosquito control are discussed

Direct and indirect effects of climate on richness drive the latitudinal diversity gradient in forest trees

Data accessibility statement: Full census data are available upon reasonable request from the ForestGEO data portal, http://ctfs.si.edu/datarequest/ We thank Margie Mayfield, three anonymous reviewers and Jacob Weiner for constructive comments on the manuscript. This study was financially supported by the National Key R&D Program of China (2017YFC0506100), the National Natural Science Foundation of China (31622014 and 31570426), and the Fundamental Research Funds for the Central Universities (17lgzd24) to CC. XW was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB3103). DS was supported by the Czech Science Foundation (grant no. 16-26369S). Yves Rosseel provided us valuable suggestions on using the lavaan package conducting SEM analyses. Funding and citation information for each forest plot is available in the Supplementary Information Text 1.Peer reviewedPostprin

The Study of PAFSSB on RO Pre-Treatment in Pulp and Paper Wastewater

AbstractReverse osmosis approach was used to dispose pulp and paper wastewater from a papermaking company. To meet the requirements of reverse osmosis membranes for water quality, a proper pretreatment had been done before raw water into RO membranes. A new efficient composite flocculant named PAFSSB had been used in the pre-treatment of pulp and paper wastewater. In the paper, the results showed that the treatment effect of PAFSSB was better, COD content was down to 10mg/L and COD removal rate was up to 75%. The pre-treatment process was simplified and processing costs were reduced

Effects of Ozone Treatment on Postharvest Mucor Rot of <i>Codonopsis pilosula</i> Caused by <i>Actinomucor elegans</i>

Fresh Codonopsis pilosula is highly susceptible to fungus contamination during post-harvest storage, which not only compromises the quality of C. pilosula but also contributes mycotoxin contamination, posing a significant threat to human health. Studies have indicated that ozone treatment can inhibit post-harvest diseases in fruits and vegetables. The impact of ozone treatment on the disease incidence, disease severity index, and weight loss rate of the fresh C. pilosula infected with Actinomucor elegans was investigated through the spray inoculation of A. elegans on C. pilosula tissues. Changes in the main active ingredients of C. pilosula after ozone treatment were analyzed, and the effects of ozone treatment on the integrity of cell membranes in C. pilosula tissue and reactive oxygen species (ROS) metabolism were studied. The results showed that ozone treatment had a significant inhibitory effect on the A. elegans-induced mucor rot in C. pilosula, significantly reducing the incidence of the disease. Compared with the control group, the ozone-treated group maintained the effective components of C. pilosula well. Furthermore, ozone treatment reduced the cell membrane permeability and Malondialdehyde (MDA) content in C. pilosula, significantly increased the activity of antioxidant enzymes in the ROS metabolism pathway, prevented oxidative stress caused by the accumulation of ROS in C. pilosula tissues, and maintained the integrity of cell membranes

Electronic and Magnetic Properties of Ni-Doped Zinc-Blende ZnO: A First-Principles Study

The electronic structure, band structure, density of state, and magnetic properties of Ni-doped zinc-blende (ZB) ZnO are studied by using the first-principles method based on the spin-polarized density-functional theory. The calculated results show that Ni atoms can induce a stable ferromagnetic (FM) ground state in Ni-doped ZB ZnO. The magnetic moments mainly originate from the unpaired Ni 3d orbitals, and the O 2p orbitals contribute a little to the magnetic moments. The magnetic moment of a supercell including a single Ni atom is 0.79 &mu;B. The electronic structure shows that Ni-doped ZB ZnO is a half-metallic FM material. The strong spin-orbit coupling appears near the Fermi level and shows obvious asymmetry for spin-up and spin-down density of state, which indicates a significant hybrid effects from the Ni 3d and O 2p states. However, the coupling of the anti-ferromagnetic (AFM) state show metallic characteristic, the spin-up and spin-down energy levels pass through the Fermi surface. The magnetic moment of a single Ni atom is 0.74 &mu;B. Moreover, the results show that the Ni 3d and O 2p states have a strong p-d hybridization effect near the Fermi level and obtain a high stability. The above theoretical results demonstrate that Ni-doped zinc blende ZnO can be considered as a potential half-metal FM material and dilute magnetic semiconductors

Air Target Threat Assessment: A Kernel Extreme Learning Machine Based on a Multistrategy Improved Sparrow Search Algorithm

Air strikes are among the main means of attack in modern warfare. To improve air defense capabilities and aid military decision-making, threat assessment models have been introduced. As the parameters of the kernel extreme learning machine (KELM) model need to be set individually, this study proposes a parameter learning strategy based on a multistrategy improved sparrow search algorithm (MISSA). First, a reasonable threat assessment model was established based on the capability and situation factors of air targets. Second, the sparrow search algorithm was improved in terms of population position initialization and position update strategy, incorporating tent chaos reverse learning, nonlinear inertia weights, a global search strategy, and adaptive t-distribution. The effectiveness of the MISSA strategy was verified using nine common benchmark functions. The results show that the proposed MISSA finds an effective balance between global and local searches. Moreover, when the MISSA is applied to solve the tuning problem of KELM, the values of mean absolute percentage error, mean square error, root mean square error, and mean absolute error for MISSA–KELM in the air target threat assessment problem are 2.013 × 10−2, 1.282 × 10−4, 1.132 × 10−2, and 8.316 × 10−3, respectively, all of which are higher than that of the other metaheuristic algorithms (e.g., ACWOA-KELM and HGWO-KELM). Therefore, the method proposed in this study can be used as a parameter-tuning tool for KELM, enabling KELM to perform better in practical applications

Selection, Identification, and Transcript Expression Analysis of Antioxidant Enzyme Genes in <i>Neoseiulus barkeri</i> after Short-Term Heat Stress

Phytoseiid mite Neoseiulus barkeri is a crucial biological control agent utilized to control pest mites and many insects in crops all over the world. However, they are vulnerable to multiple environmental pressures, with high-temperature stress being the most significant challenge. Heat stress disrupts the balance of reactive oxygen species (ROS) levels in organisms, resulting in oxidative stress within the body. Antioxidant enzymes play a crucial role in effectively neutralizing and clearing ROS. In this study, comparative transcriptomics and quantitative real-time PCR (qRT-PCR) were employed to assess the impact of short-term heat stress on the transcript expression of antioxidant enzyme genes in N. barkeri. We primarily identified four antioxidant enzyme genes (NbSOD, NbPrx, NbCAT, and NbGPX) in N. barkeri after exposure to short-term heat stress. Then, new data on the expression patterns of these genes were generated. RNA sequencing and bioinformatics analysis revealed that NbSOD belongs to the Fe/Mn family of superoxide dismutase (SOD), which was identified as MnSOD. NbPrx was classified as a 1-Cys peroxiredoxin of the peroxidase family, whereas NbCAT was recognized as a classical catalase, and NbGPX was determined as cytoplasmic glutathione peroxidase-1 (GPX1). Transcriptional expression analysis of these four genes was conducted at different high temperatures: 36 °C, 38 °C, and 40 °C for 2, 4, and 6 h. The results also showed that all four genes exhibited significant up-regulation in response to short-term heat stress. Similarly, the highest expression levels for NbSOD, NbPrx, and NbCAT were observed at 40 °C for 4 h. However, NbGPX displayed its maximum expression value at 38 °C for 4 h. Overall, the obtained data suggest that short-term heat stress increases levels of ROS generated inside living organisms, which disrupts the oxidative balance and leads to alterations in the expression levels of antioxidant enzyme genes

State Evaluation of Self-Powered Wireless Sensors Based on a Fuzzy Comprehensive Evaluation Model

The energy harvesters used in self-powered wireless sensing technology, which has the potential to completely solve the power supply problem of the sensing nodes from the source, usually require mechanical movement or operate in harsh environments, resulting in a significant reduction in device lifespan and reliability. Therefore, the influencing factors and failure mechanisms of the operating status of self-powered wireless sensors were analyzed, and an innovative evaluation index system was proposed, which includes 4 primary indexes and 13 secondary indexes, including energy harvesters, energy management circuits, wireless communication units, and sensors. Next, the weights obtained from the subjective analytic hierarchy process (AHP) and objective CRITIC weight method were fused to obtain the weights of each index. A self-powered sensor evaluation scheme (FE-SPS) based on fuzzy comprehensive evaluation was implemented by constructing a fuzzy evaluation model. The advantage of this scheme is that it can determine the current health status of the system based on its output characteristics. Finally, taking vibration energy as an example, the operational status of the self-powered wireless sensors after 200 h of operation was comprehensively evaluated. The experimental results show that the test self-powered wireless sensor had the highest score of “normal”, which is 0.4847, so the evaluation result was “normal”. In this article, a reliability evaluation strategy for self-powered wireless sensor was constructed to ensure the reliable operation of self-powered wireless sensors

Density Functional Theory Study of Electronic Structure and Optical Properties of Ln³⁺-Doped γ-Bi₂MoO₆ (Ln=Gd, Ho, Yb)

Based on density functional theory (DFT), theoretical models of three kinds of lanthanide rare earth metal ion-doped γ-Bi2MoO6 were constructed (Ln-BMO (Ln=Gd, Ho, Yb)). The geometric structure, electronic structure, and optical properties of the model were calculated, and the influence of doped Ln3+ ions on the structures and properties of the system was analyzed. The results revealed that the substitution of smaller ionic radius Ln3+ ions for Bi3+ ions caused a contraction of the lattice parameters. At the same time, the contribution of the [Ln]4d near valence band and conduction band reduced the bandwidth of γ-Bi2MoO6, forming the Ln-O ionic bond with different strengths to obtain higher charge conductivity and charge-separation ability. Secondly, Ln3+ ions have a strongly ionic charge, which leads to the appearance of optical absorption bands in the infrared region and part of the visible region. This reduces the reflection in the visible region, improves the utilization rate, delays the loss of electron energy, and promotes phase matching in the visible region. And the Gd3+-doped system has better photocatalytic activity than the other Ln3+-doped system. This research provides theoretical insights into doped lanthanide rare earth ions and also provides strategies for the modification of γ-Bi2MoO6 nanomaterials