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Numerous bed bug research papers have been published in the past 20 yr as a result of bed bug (Cimex spp.) (Hemiptera: Cimicidae) resurgence in the world. Yet, few of them focused on the management of the tropical bed bug, C. hemipterus (F.). Here, we describe a case of tropical bed bug infestation in two dormitory buildings and effectiveness of a tropical bed bug treatment program. The study site consisted of 125 dormitories in two buildings. An initial building-wide monitoring with ClimbUp interceptors revealed 25 infestations. The spatial distribution of bed bug infested rooms showed a significant aggregated distribution pattern with same infestation status for neighboring units sharing walls. All infested rooms were monitored every 2 wk and treated using a combination of steam and diatomaceous earth (DE) dust application if bed bugs were still found. For the 25 initially identified infested rooms, after 14 wk treatment, 44% of them no longer had bed bugs, and the mean number of bed bugs captured per room decreased by 94.1%. A combination of steam and DE dust treatment is an effective strategy for suppressing tropical bed bug infestations in dormitory environment.

Accidental falls represent a major cause of fatal injuries for construction workers. Failure to seek medical attention after a fall can significantly increase the risk of death for construction workers. Wearable sensors, computer vision, and manual techniques are common modalities for detecting worker falls in the literature. However, they are severely constrained by issues such as cost, lighting, background, clutter, and privacy. To address the problems associated with the existing proposed methods, a new method has been conceived to identify construction worker falls by analyzing the CSI signals extracted from commercial Wi-Fi routers. In this research context, our study aimed to investigate the potential of using Channel State Information (CSI) to identify falls among construction workers. To achieve the aim of this study, CSI data corresponding to 360 sets of activities were collected from six construction workers on real construction sites. The results indicate that (1) the behavior of construction workers is highly correlated with the magnitude of CSI, even in real construction sites, and (2) the CSI-based method for identifying construction worker falls has an accuracy of 99% and can also accurately distinguish between falls and fall-like actions. The present study makes a significant contribution to the field by demonstrating the feasibility of utilizing low-cost Wi-Fi routers for the continuous monitoring of fall incidents among construction workers. To the best of our knowledge, this is the first investigation to address the issue of fall detection using commercial Wi-Fi devices in real-world construction environments. Considering the dynamic nature of construction sites, the new method developed in this study helps to detect falls at construction sites automatically and helps injured construction workers to seek medical attention on time.

Ground-level ozone (O

Studies showing that deserts can sequester CO

In order to investigate the effect of Wolbachia on fitness of their hosts, the biological characteristics of a primarily parthenogenetic line and a bisexual restored line (obtained by antibiotic treatment) of Trichogramma pretiosum were compared in the laboratory. Results indicated that both the mean longevity and fecundity of parthenogenetic line (14.2 d and 165 eggs/female) were significantly higher than those in bisexual restored line (8.4 d and 124.2 eggs/female). Both lines of T. pretiosum had the highest daily fecundity (23.3 eggs/female for parthenogenetic line and 19.8 eggs/female for bisexual restored line) on the first day during their reproduction period, and their survival rate and daily fecundity decreased gradually with age; however, the survival rate and daily fecundity of the parthenogenetic line were always higher than those of bisexual restored line, during the entire experimental period. There was no significant difference in emergence rate and deformity rate between the two T. pretiosum lines. The life-table parameter results indicated that net reproduction rate (R0) and mean generation time (T) in parthenogenetic line (133 and 16.8) were significantly higher than those in bisexual restored line (61.7 and 15.5); intrinsic rate of natural increase (rm) and finite rate of increase (λ) in parthenogenetic line (0.29 and 1.34) were higher than those in bisexual restored line (0.26 and 1.3). Based on these results, it can be confirmed that the removal of Wolbachia in the parthenogenetic line had an adverse effect on fitness of T. pretiosum.

Rising CO2 concentration and temperatures in urban areas are now well-known, but the potential of an emerging oxygen crisis in the world's large cities has so far attracted little attention from the science community. Here, we investigated the oxygen balance and its related risks in 391 global large cities (with a population of more than 1 million people) using the oxygen index (OI), which is the ratio of oxygen consumption to oxygen production. Our results show that the global urban areas, occupying only 3.8% of the global land surface, accounted for 39% (14.3 ± 1.5 Gt/yr) of the global terrestrial oxygen consumption during 2001-2015. We estimated that 75% of cities with a population more than 5 million had an OI of greater than 100. Also, cities with larger OI values were correlated with more frequent heatwaves and severe water withdrawals. In addition, cities with excessively large OI values would likely experience severe hypoxia in extremely calm weather. Thus, mitigation measures should be adopted to reduce the urban OI in order to build healthier and more sustainable cities.

Major disruptions, often caused by locked m/n = 2/1 modes (m/n is the poloidal/toroidal mode number), are great threat to a tokamak fusion reactor and should be mitigated or avoided. The locked 2/1 modes have been unlocked by electrode biasing (EB) for the first time in J-TEXT tokamak experiments. The application of a sufficiently negative EB voltage in plasma edge region quickly changes the phase and amplitude of the locked 2/1 mode and drives the mode to rotate in about 10–30 ms. For a larger EB current or a smaller locked mode amplitude, the mode is more easily to be unlocked, revealing a new method for mode unlocking and avoiding plasma disruptions.

In the last two years, three major technical improvements have been made on J-TEXT in supporting of the expanded operation regions and diagnostic capabilities. (1) The successful commission of the 105 GHz/500 kW/1 s electron cyclotron resonance heating (ECRH) system increasing the core electron temperature from 0.9 keV up to around 1.5 keV. (2) The poloidal divertor configuration with an X-point in the high-field side has been achieved. In particular, the 400 kW electron cyclotron wave has also been successfully injected into the diverted plasma. (3) A 256-channel electron cyclotron emission imaging diagnostic system and two sets of four-channel Doppler backscattering diagnostics have been successfully developed on J-TEXT, allowing detailed measurement of the electron temperature and density fluctuations for turbulence and MHD research. The locked mode (LM), especially the 2/1 LM, is one of the biggest threats to the plasma operation. Both the thresholds of 2/1 and 3/1 LM are observed to vary non-monotonically on electron density. The electrode biasing was applied successfully to unlock the LM from either a rotating or static resonant magnetic perturbation (RMP) field. In the presence of 2/1 LM, three kinds of standing wave (SW) structures have been observed to share a similar connection to the island structure, i.e. the nodes of the SWs locate around the O- or X-points of the 2/1 island. The control and mitigation of disruption is essential to the safe operation of ITER, and it has been systematically studied by applying a RMP field, massive gas injection (MGI) and shattered pellet injection on J-TEXT. When the RMP-induced 2/1 LM is larger than a critical width, the MGI shutdown process can be significantly influenced. If the phase difference between the O-point of LM and the MGI valve is +90° (or −90°), the penetration depth and the assimilation of impurities can be enhanced (or suppressed) during the pre-thermal quench (TQ) phase and result in a faster (or slower) TQ. A secondary MGI can also suppress the runaway electron (RE) generation, if the additional high-Z impurity gas arrives at the plasma edge before TQ. When the secondary MGI has been applied after the formation of the RE current plateau, the RE current can be dissipated, and the dissipation rate increases with the injected impurity quantity but saturates with a maximum of 28 MA s−1. The non-local transport is experimentally observed in the ion transport channel. The electron thermal diffusivity significantly increases with the ECRH power. Theoretical work shows that significant intrinsic current can be driven by electromagnetic turbulence, and the robust formation mechanism of the E × B staircase is identified from the Hasegawa–Wakatani system.

To investigate the buoyancy characteristics of building façades, this study deals with experimental and numerical investigations on building façade flow and temperature field in different façade temperature conditions with different height-aspect ratio of building facade. PIV measurements are conducted in a static wind platform for obtaining the mean velocity, the vertical velocity and the horizontal velocity around the building surface. To simulate the plume characteristics accurately, this study adopt three numerical model and compared the numerical results with the PIV experimental data. The result indicated that the simulation result of the RNG k-ε model best agreement with experimental data. Analysis of numerical results indicated that the wind speed kept increasing in the vertical direction, while the wind speed first increased and then decreased in the horizontal direction. The air temperature tended to be constant in the vertical direction, but air temperature first drooped sharply and tended to be constant in the horizontal direction. As the heat flow density increases, the building facade plume strength increases. When the wall heat flow increases from 100W/m2 to 200 W/m2, the maximum velocity of the wall increases by 1.6 m/s and the temperature increases by 15 °C.

The temperature in the urban areas are higher compared with rural areas because of the UHI effect. The wind-driven ventilation play a significant role on the heat removal. Moreover, the air velocity in the urban areas is influenced by the background wind speed, the exposure of heated surfaces and building layout. However, available experimental data for the thermal diffusion mechanism of different heat source conditions and building layout is limited. Aim at the problem above, the thermal diffusion mechanism of different surface heating conditions and building layout was analysed by conducting wind tunnel experiment with PIV system. To investigate the thermal diffusion mechanism, the building façade, impervious road surface, and traditional roof are heated up three different temperatures to induce buoyant. The effects of three different buildings layouts on flow and temperature also were investigated in this paper. The results showed that building layouts had a marked impact on the flow field near buildings. The terraced building layout is best for heat removal. This study improves understanding of how the buoyancy and wind speed influence the thermal diffusion in different buildings layouts, expands experimental database under different surface temperature conditions and buildings layouts in wind tunnel experiments with PIV.

From the 1960s to the 1980s, with the implementation of nationwide ‘Four-Pest Elimination’ campaigns (bed bugs, Cimex lectularius L. and Cimex hemipterus (F.) (Hemiptera: Cimicidae), were listed as one of the targeted pests), bed bug infestations were gradually eliminated in most provinces in China. However, during the last two decades, reports of bed bug infestations in the Pearl River Delta of China have shown an upward trend. Up to now, the bed bug species occurring in this area was much less frequently reported. In this study, we used both morphological and molecular methods to accurately identify the species of bed bugs collected from the cities of Guangzhou and Foshan, China. Results indicated that no significant difference was observed in the mean pronotum width-to-length ratio of Guangzhou (2.6) and Foshan (2.4) specimens; however, both were significantly lower than that of a laboratory strain C. lectularius (3.1). The genetic distances of our specimens with C. hemipterus and C. lectularius were 0–0.2% and 22.2–22.6%, respectively. On the basis of the morphological characteristics and mitochondrial DNA sequence data, it can be affirmed that bed bugs collected from Guangzhou and Foshan were C. hemipterus.

This paper investigates the high frequency response of the Mirnov probe based on a test platform, which is capable of generating a uniform AC magnetic field within the frequency range of 1–300 kHz. The eddy current effect is quantitatively reflected by the phase shift ϕc and normalized amplitude δ of the measured magnetic field between cases with and without a conducting plate located near the Mirnov probe. This method compensates the resonant effect in the Mirnov probe circuit and hence reflects purely the eddy current effect. The eddy current effect increases with the decrease in the distance between the probe and the conducting plate. With the increase in frequency, the magnitude of δ decreases to a saturated value at 10 kHz but increases significantly above 100 kHz for 304-stainless steel, while the eddy current effect with graphite appears at around 10 kHz and the magnitude of δ decreases to the minimum at 125 kHz, followed by a significant increase above 125 kHz. With the increase in f, the magnitude of ϕc increased until 2.5 kHz and 40 kHz for steel and graphite, respectively, then decreased with a further increase in f. The phasor expression is introduced to describe the AC magnetic field and allows an easy expression of the eddy current field. The phase of the eddy current field decreases toward −180° with f. The amplitude of the eddy current field increases with f and reaches its maximum when the skin depth reduces to a critical value. The eddy current field decreases with a further increase in the frequency.

Drylands are one of the most sensitive areas to anthropogenic climate change and are projected to experience accelerated expansion throughout the end of this century. However, the responses of drylands degradation to anthropogenic ecosystem changes remain unclear. This study proposes a new perspective of the ‘oxygen footprint’, defined as the ratio between oxygen consumption and oxygen production, which could be regarded as an indicator in evaluating the effects of anthropogenic climate change on global dryland ecosystems. A global distribution of the trend of oxygen footprint in response to climate change indicators and the transformations for ecosystem functioning is presented. The response of oxygen footprint to human activities and global warming is projected to enhance in the 21st century. Under a high emissions scenario (RCP8.5), linear regression analysis between oxygen footprint and other indicators shows oxygen footprint to increase with the increase of air temperature, precipitation, potential evapotranspiration and dryland areas, respectively. Our study suggests that when oxygen production is unsustainable combined with oxygen consumption, this scenario will accelerate the degradation of dryland ecosystem, with fundamental and negative consequences for the capacity of drylands to supply essential ecosystem services.

Magnetohydrodynamic (MHD) instabilities are widely observed during tokamak plasma operation. Magnetic diagnostics provide important information which supports the understanding and control of MHD instabilities. This paper presents the current status of the magnetic diagnostics dedicated to measuring MHD instabilities at the J-TEXT tokamak; the diagnostics consist of five Mirnov probe arrays for measuring high-frequency magnetic perturbations and two saddle-loop arrays for low-frequency magnetic perturbations, such as the locked mode. In recent years, several changes have been made to these arrays. The structure of the probes in the poloidal Mirnov arrays has been optimized to improve their mechanical strength, and the number of in-vessel saddle loops has also been improved to support better spatial resolution. Due to the installation of high-field-side (HFS) divertor targets in early 2019, some of the probes were removed, but an HFS Mirnov array was designed and installed behind the targets. Owing to its excellent toroidal symmetry, the HFS Mirnov array has, for the first time at J-TEXT, provided valuable new information about the locked mode and the quasi-static mode (QSM) in the HFS. Besides, various groups of magnetic diagnostics at different poloidal locations have been systematically used to measure the QSM, which confirmed the poloidal mode number m and the helical structure of the QSM. By including the HFS information, the 2/1 resonant magnetic perturbation (RMP)-induced locked mode was measured to have a poloidal mode number m of ∼2.

An understanding of the global terrestrial carbon cycle is crucial to predict future climate change. Deserts are an important part of the terrestrial ecosystem, but their role in the terrestrial carbon cycle has long been neglected. Recent studies have shown that deserts may sequester enormous volumes of CO2 and play a pivotal role as a carbon sink. As the world’s second-largest shifting desert, the Taklimakan Desert (TD) contributes substantially to the global desert carbon sink. However, the contributions of the internal processes of the TD to its carbon sink and the long-term trend of the carbon sink under climate change are still unclear. Based on an observational study, we determined that both the expansion/contraction of soil air containing CO2 caused by heat fluctuation in shifting sand and the salt/alkali chemistry control the release/absorption processes of soil respiration in shifting sand. Besides, the mutual offset of these processes indicates that the shifting sand in the TD acts as a stable carbon sink at present, with an annual average CO2 uptake rate of 7.11 g m−2. However, an increase in soil temperature difference will stimulate soil air expansion and release more CO2 into the atmosphere under climate change, gradually lessening the carbon sink rate of shifting sand in TD in the future. These processes will be accelerated by a positive feedback loop, where this effect triggered by climate change will enhance regional warming. Our results highlight the status of deserts in the global carbon cycle and provide crucial information regarding the world’s missing carbon sink.

Ecological security is the state when an ecosystem maintains its stability under external stress. Due to climate change and the increase in human activities since the 20th century, the rapid decline in global ecological security has threatened sustainable human development. The evaluation and projection of global ecological security is important for forming adaptation strategies to maintain sustainable development in sensitive areas. However, the current assessments of ecological security mainly focus on regional scales, and the interactions among different factors have not been considered, resulting in future projections having substantial uncertainty. Here, a new index of ecological security was developed by including biological, oxygen, carbon, thermal and hydrological cycles and the impacts to ecosystem stability from climate change and human activities at a global scale. A global distribution map of ecological security has been established that covers the past 60 years and includes projections for the future 100 years. A severe decline in ecological security has occurred in drylands that has expanded into surrounding regions over the past 60 years. The response of ecological security to global warming and human activities is projected to be stronger. By ~2100, under a high greenhouse gas emissions scenario, the amount of globally insecure land would cover more than 57% of the land in the world.

The remediation of fluorine-contaminated kaolin using ammonia enhanced electrokinetics coupled with bamboo charcoal adsorption was assessed. Six electrokinetic experiments were conducted in self-made electrokinetic apparatus with deionized water as catholyte. Ammonia with concentration of 0, 0.01 and 0.1 mol/L was used as anolyte, and the voltage gradient was set at 1.0 and 1.5 V/cm. Bamboo charcoal was loaded in the central part of the electrolytic cell as adsorbent to adsorb various forms of fluorine pollutants migrating here. The effects of different ammonia concentration and voltage gradient on the removal of soil fluorine were analyzed. Ammonia enhanced electrokinetic not only increased electric current, but also changed the pH values of catholyte, anolyte and soil which made different fluorine speciation exist in soil such as anions F − , HF 2 − and cations (AlF) 2+ , AlF 2 + . The removal of fluorine increased significantly with the concentration of the ammonia, which indicated that ammonia could facilitate soil fluorine to transform into dissolved form effectively and desorption of soil fluorine was a key limiting factor for fluorine-contaminated soil by electrokinetics. F − , HF 2 − , and (AlF) 2+ , AlF 2 + in soil solution had opposite charges and moved in reverse direction under the function of electrokinetics, which caused fluorine pollutants to move to the central section of the electrolytic cell, where they were adsorbed exactly by the bamboo charcoal loaded there. The maximum adsorption capacity of fluorine by bamboo charcoal was 3.17 mg/g and the removal rate of soil fluorine reached 75.70%. The integration of ammonia enhanced electrokinetics with bamboo charcoal adsorption as a hybrid method was most effective for the remediation of fluorine-contaminated soil.

To study the effect of tongfei mixture (TFM, a Chinese recipe mainly consisted of angelica and rehmannia root) on nocturnal hypoxia in patients with chronic obstructive pulmonary disease (COPD).Sixty patients with COPD of remission phase were randomly divided into 3 groups, 20 in each group. Group A was the control group; Group B, the group simply treated with oxygen; Group C, treated with oxygen and TFM. Changes of pulmonary function, diaphragm muscle mobility (DMM), 6 min walk distance (6MWD), morning arterial blood gas, nocturnal lowest oxygen saturation (LSaO2), mean blood oxygen saturation (MSaO2), the percentage of saturation lower than 90% time account for total sleeping time (SLT90%) and ultrasonocardiogram before and after treatment were observed.Levels of LSaO2, MSaO2 and SLT90% in Groups B and C were significantly higher than those in Group A (P0.05, P0.01). The lowering of PaCO2 in Group C was more significant than that in Group B (P0.05). The mPAP level in Group C was lower, FEV1, 6MWD and DMM were improved than those in Group A and B, showing significant difference (P0.05).Combined use of oxygen therapy and TFM could not only improve the nocturnal hypoxia, but also lower PaCO2. TFM is an important supplement of oxygen therapy.