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Aims: Changes in global precipitation regimes are caused by an increase in the frequency of extremely wet and dry years inter-annually and extreme rainfall intensity intra-annually. However, the interactive effects of these precipitation variabilities remain relatively unclear. Methods: To better understand the responses of semi-arid ecosystems to precipitation changes, a manipulative field experiment was conducted with multilevel annual precipitation amounts and precipitation allocation, at a temporal scale, within desert shrubland in the Mu Us Desert in northern China. Results: With fewer, yet larger, precipitation events, the annual net primary production (ANPP) was found to increase in dry years. The annual precipitation amount and precipitation intervals affected the community ANPP. However, precipitation intervals only affected the ANPP in the context of low precipitation amounts. Extending the intervals between precipitation events significantly increased the ANPP of shrubs and weeds however decreased that of grasses. The nursery effect of shrubs on the herbs and competition between the grass and weeds can interfere with the response of the community ANPP to precipitation. Conclusions: With a global shift toward precipitation regimes dominated by lower frequency and higher intensity, an increase in productivity in this desert shrubland ecosystem is expected, with shrubs largely dominating the community composition. This study advances the current understanding of how community productivity is shaped by the interaction between inter-annual precipitation amount and intra-annual precipitation distribution. Meanwhile, plant–plant interactions between different functional species also have essential roles in community productivity stabilization within the context of precipitation change. [ABSTRACT FROM AUTHOR]

Background Published guidelines on decision-making and resuscitation of extremely preterm infants primarily focus on high-income countries. For rapidly industrializing ones like China, there is a lack of population-based data for informing prenatal management and practice guidelines. Methods The Sino-northern Neonatal Network conducted a prospective multi-centre cohort study between 1 January 2018 and 31 December 2021. Infants with a gestational age (GA) between 22 (postnatal age in days = 0) and 28 (postnatal age in days = 6) admitted to 40 tertiary NICUs in northern China were included and evaluated for death or severe neurological injury before discharge. Results For all extremely preterm infants (n = 5838), the proportion of admission to the neonatal was 4.1% at 22-24 weeks, 27.2% at 25-26 weeks, and 75.2% at 27 and 28 weeks. Among 2228 infants admitted to the NICU, 216 (11.1%) were still elected for withdrawal of care (WIC) due to non-medical factors. Survival rates without severe neurological injury were 6.7% for infants at 22-23 weeks, 28.0% at 24 weeks, 56.7% at 24 weeks, 61.7% at 25 weeks, 79.9% at 26 weeks, and 84.5% at 27 and 28 weeks. Compared with traditional criterion at 28 weeks, the relative risk for death or severe neurological injury were 1.53 (95% confidence interval (CI) = 1.26-1.86) at 27 weeks, 2.32 (95% CI = 1.73-3.11) at 26 weeks, 3.62 (95% CI = 2.43-5.40) at 25 weeks, and 8.91 (95% CI = 4.69-16.96) at 24 weeks. The NICUs with higher proportion of WIC also had a higher rate of death or severe neurological injury after maximal intensive care (MIC). Conclusions Compared to the traditional threshold of 28 weeks, more infants received MIC after 25 weeks, leading to significant increases in survival rates without severe neurological injury. Therefore, the resuscitation threshold should be gradually adjusted from 28 to 25 weeks based on reliable capacity. [ABSTRACT FROM AUTHOR]

Although the influence of mechanical sand control techniques on vegetation on degraded sand dunes has received much attention for a long time, our understanding of the underlying processes of plant community formation is not yet strong. Analyses of trends in the turnover and nestedness components of beta diversity can be informative of the process of response to sand dune stabilization. In this study, we applied a field investigation of sand dunes at different stabilization stages in northern China. We then used Baselga's method to calculate total beta diversity and partition it into spatial turnover and nestedness to clarify the underlying community change processes. Our study indicated that the implementation of straw checkerboard techniques significantly increased the beta diversity of the community, leading to species heterogeneity. Species turnover was the main contributor to species beta diversity, and it was caused by high environmental heterogeneity with sand dune stabilization. The contribution of the nestedness component to beta diversity decreased with dune stabilization, indicating that with stabilization, dissimilarity was largely driven by variation in community composition rather than differences in taxonomic richness. This study provides insights into the underlying variation in species composition among sites where mechanical sand fixation engineering has been implemented and important guidelines for combating desertification. [ABSTRACT FROM AUTHOR]

Cryptosporidium is an important zoonotic parasite that can infect a variety of hosts, including pigs and humans, through water and food. Many studies on Cryptosporidium infection in pigs have been reported worldwide. However, the meta‐analysis of Cryptosporidium infection in pigs in China has not been published. This study retrieved articles related to Cryptosporidium in pigs in China by using four databases: Chinese National Knowledge Infrastructure (CNKI), PubMed, VIP Chinese journal database and Wanfang Data. We retrieved 40 studies related to Cryptosporidium infection in China, and those articles were harvested from the inception to 1 January 2020. We estimated that the overall prevalence of pigs with Cryptosporidium in the selected period was 12.2% (4,349/30,404). In the sampling year subgroup, the prevalence rate after 2010 was the lowest at 8.7% (2,087/18,100). In Northern China, the Cryptosporidium prevalence was 47.9% (34/71). By contrast, the prevalence of Cryptosporidium in Southwestern China was only 6.9% (778/6,445). The infection rate of Cryptosporidium in diarrhoea pigs of 15.6% (74/384) was higher than that in non‐diarrhoea pigs at 10.8% (378/2,840). Among the four age groups, the prevalence of weaning pigs of 16.2% (530/3,243) was the highest, and the difference was significant (p <.05). The prevalence of Cryptosporidium in extensive farming was 25.7% (660/3,121), which was significantly higher than in intensive farming 8.7% (566/6,336), and the prevalence of infection was related to the farming modes (p <.05). We also analysed the impact of different geographic factor subgroups (longitude, latitude, precipitation, temperature, humidity, climate and altitude) on the prevalence of pigs. The results showed that cryptosporidiosis was widespread in pigs in China. We suggest that appropriate control schemes should be developed according to the differences in breeding patterns and geographic conditions in different regions, and effective management measures should be developed to reduce the spread between pigs. [ABSTRACT FROM AUTHOR]

Toxoplasma gondii and Chlamydia are common protozoan pathogens, which can pose health risks to people around the world and cause considerable economic losses. Although information on the seroprevalence of T. gondii and Chlamydia in chickens can be found in China, knowledge on the infection of these two diseases in rural chickens, ducks, and geese is limited. Therefore, blood samples from 377 chickens, 268 ducks, and 379 geese were taken from rural areas in seven cities in northeastern China, and their seropositivity was analyzed by the indirect hemagglutination antibody (IHA) test with a cutoff titer of 1:64. The overall seroprevalence of T. gondii and Chlamydia was 10.6% and 21.0%, respectively. Moreover, the free-range poultry (20.75% and 30.55%) have significantly higher seroprevalences than caged poultry (5.47% and 15.66%) (p < 0.001). Moreover, the seroprevalence of T. gondii in older and younger poultry was found to be 5.48% and 12.89%, and those in Chlamydia were 23.53% and 15.16%, respectively. There were significant differences between different ages (p < 0.05). But regarding the prevalence of both, it is not clear in this way which one is the prevalence for younger and older for each specific pathogen. Logistic regression analysis suggested that geography were considered as a risk factor for T. gondii infection in this study. Our study is the first report on the seroprevalence of T. gondii and Chlamydia in poultry in rural areas of Jilin Province, China. These data reflect that T. gondii and Chlamydia are widespread in poultry in northeastern China, leading to a risk of infection in human health. Therefore, the prevention and control of Toxoplasma and Chlamydia infection in poultry, other animals, and humans should be strengthened. [ABSTRACT FROM AUTHOR]

Water scarcity is the most critical constraint for sustainable cotton production in Xinjiang Province, northwest China. Drip irrigation under mulch is a major water-saving irrigation method that has been widely practiced for cotton production in Xinjiang. The performance of such an irrigation system should be evaluated for proper design and management. Therefore, a field experiment and a simulation study were conducted to (1) determine a modeling approach that can be applied to manage drip irrigation under mulch for cotton production in this region; and (2) examine the effects of irrigation amount and mulch on soil water distribution and root zone water balance components. In the experiment, four irrigation treatments were used: T1, 166.5 m3; T2, 140.4 m3; T3, 115.4 m3; and T4: 102.3 m3. The HYDRUS-2D model was calibrated, validated, and applied with the data obtained in this experiment. Soil water balance in the 0-70 cm soil profile was simulated. Results indicate that the observed soil water content and the simulated results obtained with HYDRUS-2D are in good agreement. The radius of the wetting pattern, root water uptake, and evaporation decreased as the amount of irrigation was reduced from T1 to T4, while a lot of stored soil water in the root zone was utilized and a huge amount of water was recharged from the layer below 70 cm to compensate for the decrease in irrigation amount. Mulch significantly reduced evaporation by 11.7 mm and increased root water uptake by 11.2 mm. Our simulation study suggests that this model can be applied to provide assistance in designing drip irrigation systems and developing irrigation strategies. [ABSTRACT FROM AUTHOR]

Background Inconsistent results have been found on the association between air pollution and stroke mortality. Additionally, evidence on people who are potentially sensitive to air pollution-associated stroke mortality is limited. Methods Daily stroke mortality of adults aged over 65 between 2003 and 2008 in Shanghai, China were collected. The time-stratified case-crossover approach was used to assess the association between daily concentrations of air pollutants including particles with size <10 µm, sulfur dioxide (S02) and nitrogen dioxide (N02) and stroke mortality. Results Both total-stroke and ischaemic-stroke mortalities were found to be significantly associated with all three air pollutants. Haemorrhagic stroke was significantly associated with S02 and N02 only. Substantial differences were observed for effect estimates of ischaemic-stroke mortality in relation to N02 among people with cardiac diseases compared with those without; for an increase of 10 µg/m3 in N02, the increase in ischaemic-stroke mortality was 7.05% (95% CI 1.92% to 12.17%) for people with comorbid cardiac diseases versus 0.60% (95% CI −0.49% to 1.68%) for those without. We did not find evidence of effect modification by hypertension and diabetes. Conclusions This study provides new evidence for the association between exposure to ambient air pollution and stroke mortality. Our results also suggest that underlying cardiac disorder may increase the risk for ischaemic-stroke mortality in relation to air pollution exposure, especially N02. [ABSTRACT FROM AUTHOR]

Bacteria carried by the pine wood nematode (PWN), Bursaphelenchus xylophilus, from both healthy and diseased Pinus thunbergii and P. massoniana were studied in five main pine wilt disease epidemic provinces in P. R. China. No bacteria were found in healthy pines but were found on PWN from all samples collected from diseased trees. Twenty-four bacteria strains were isolated from the nematodes and were identified by a combination of classical and automatic testing bacteriology (ATB) expression methods. Bioassay showed that 17 of the 24 identified strains produced phytotoxins. Eleven of these 17 phytotoxin producers belonged to the genus Pseudomonas. Glasshouse and field inoculation tests using sterile techniques showed that both PWN and the toxin-producing bacteria carried were necessary to induce disease. We hypothesise that pine wilt disease is a complex, induced by both PWN and the bacteria it carries. [ABSTRACT FROM AUTHOR]

Pulmonary fibrosis (PF) could severely disrupt the normal lung architecture and function with fatal consequences. Currently, there is no effective treatment for PF or idiopathic pulmonary fibrosis (IPF). The aim of this study was to investigate the effects of Sodium Houttuyfonate (SH) on bleomycin (BLM) induced PF mice model. Our results indicated that SH could attenuate BLM induced lung injury by reducing the inflammation, fibrogenesis and lung/body weight ratio. The proposed mechanisms for the protective effects of SH include: 1) improvement of pulmonary function in BLM mice, for instance, it can elevate the vital capacity (VC), increase the forced expiratory flow at 50% of forced vital capacity (FEF50) and improve other pulmonary function indices; 2) inhibition of collagen formation in BLM mice; 3) attenuation of the elevation of inflammatory cytokines, such as interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α), which are triggered by BLM administration; 4) reduction of the mRNA level and protein production of transforming growth factor-β1 (TGF-β1) in BLM mice. Furthermore, it was found that the protective effects of SH against BLM induced PF in mice was comparable to that of prednisone acetate (PA) tablets, a widely used drug for immunological diseases. Although Houttuynia Cordata Thunb has been widely used in China for lung infection and inflammation, the mechanism has not yet been fully elucidated. Our study provides the evidence that SH is an effective compound against pulmonary injury, irritation and fibrogenesis. [ABSTRACT FROM AUTHOR]

The two-dimensional overland flow simulation program, FullSWOF_2D, was revised to include submodules of determining infiltration by zones (Z) and grate-inlet (G) drainage from a 2D surface to a 1D pipe flow. The updated program, FullSWOF-ZG, was used to evaluate the performance of a road-bioretention strip (RBS) system and explore/understand key parameters of continuous RBS design. The program was validated using eight pervious surfaces under simulated rainfall events and tested with 20 experimental cases of a locally depressed curb inlet. The mean difference of simulated interception efficiencies (36.6%–86.0%) and observed interception efficiencies (34.8%–84.0%) of the curb inlet was 3.5%, which proves the program predicts the curb-inlet interception efficiency accurately. The 20 road-only and 20 RBS modeling cases were designed and modeled using the FullSWOF-ZG program. These case studies have different road lengths, curb inlet lengths, longitudinal slopes, cross slopes, bioretention-overflow inlet heights, and bioretention soil infiltration parameters. Only 34.6%–48.4% of the total runoff volume is intercepted by the RBS's curb inlet under heavy rainfall (250 mm/h) and the remaining part of the runoff flows downstream along the road, which may cause local inundation and become a safety hazard. The curb inlet becomes the bottleneck of the RBS system that could impede the runoff flowing into the bioretention strip for detention and infiltration to improve the stormwater quality. [ABSTRACT FROM AUTHOR]

Biodiesel is a non-toxic and biodegradable substitute for petroleum-based diesel. However, it is impractical to use refined edible oils to produce biodiesel due to its high cost and priority for food products, especially in China, while waste oils with high free fatty acids (FEAs) can be considered as the raw materials. In the present work, a solid acid catalyst comprising So4²-/TiO2-SiO2 was prepared, characterized and studied for its activity for the production of biodiesel from several low cost feedstocks with high FPAS. The solid acid catalyst can be recycled, easily removed and can simultaneously catalyze esterification and transesterification. The influence of reaction parameters was studied, and the optimized reaction parameters are reaction temperature 200°C, molar ratio of methanol to oil 9:1 and catalyst concentration 3 wt.%. The catalyst showed good stability. A continuous process for biodiesel production from cheap raw feedstocks was proposed, and a 10,000-tonnes/year biodiesel production demonstration plant has been built. [ABSTRACT FROM AUTHOR]

The temperature control of the spallation target in accelerator driven subcritical system is the important issue that has the direct impact on stable and reliable operation of the coupling system. The China initiative accelerator driven subcritical system (CiADS) is composed by three facilities, including the high power accelerator, dense granular spallation target (DGT) and the subcritical reactor, where the DGT is the key component in connecting the accelerator and subcritical reactor, and the gravity driven tungsten alloy granules are considered as the material and coolant for the spallation target. In order to keep the working temperature in normal operation condition around the presetting value without bringing the large perturbation, the intensity of proton beam and the flow speed of tungsten alloy granules are considered as the main control approaches in adjusting the temperature inside the DGT, and the proportional integral derivative (PID) controller has been established based on the two approaches for the better adaptability to the temperature control in spallation target system. Moreover, the simulation method and quantum evolutionary algorithm have been employed for the selection and optimization of main parameters in PID controller in order to substitute the time consuming and error prone tasks in traditional experiential selection process. Finally, the reference control scenarios have been used to demonstrate the feasibility and applicability of optimized method for the temperature control of the DGT system in CiADS. Image 1 • Control approaches of granular flow speed and beam intensity have been employed. • Logical structure of PID temperature controller has been established for DGT. • Quantum evolutionary algorithm has been used for temperature control of DGT. • Evolution of parameters in PID controller has been analyzed in predefined scenarios. [ABSTRACT FROM AUTHOR]

Enterocytozoon bieneusi (E. bieneusi) is an important zoonotic microsporidian pathogen that has a variety of hosts. Cattle are reservoir hosts of E. bieneusi, and play an important role in the epidemiology of E. bieneusi. However, no systematic research on the prevalence of E. bieneusi in cattle has been reported. Here, a systematic review and meta-analysis was performed to determine the prevalence of E. bieneusi in cattle. Six databases (PubMed, Web of Science, Springlink, Wanfang, CNKI, and VIP) were used for searching for relevant studies. The quantity of E. bieneusi infection in cattle was extracted and subjected to an estimation for the prevalence in cattle by using a random effects model. In total, forty articles from 12 countries were chosen from 524 studies from inception to 1st June 2021. An overall E. bieneusi prevalence (95% CI) in cattle was 12.9% (2566/19,791, 9.0-14.6%). The highest prevalence of E. bieneusi was 17.3% (13.9-20.3) in South America, and the lowest was 6.5% (4.1 - 9.4) in Africa 6.5%. The prevalence of E. bieneusi after 2016 (11.1%) was lower than 2016 and before (12.3%). Cattle aged 3-12 months had a higher prevalence (14.8%) as compared with cattle aged > 12 months (8.2%). The combined prevalence of E. bieneusi in the dairy cattle was 14.4%, which was higher than that in other species. In the subgroup of season, E. bieneusi prevalence in cattle was higher in spring (17.4%) and autumn (19.7%) than in summer (8.5%) and winter (8.5%). E. bieneusi prevalence in naturally grazed cattle was 3.6% and 13.7% in intensively fed cattle. A total of 83 E. bieneusi genotypes were prevalent in cattle, of which 15 genotypes found in the cattle had previously been found in humans. The global prevalence of E. bieneusi in cattle related to geographical and climate variables were evaluated as well. These data indicated that E. bieneusi was ubiquitous in cattle worldwide and carried a potential risk of infection in humans. Thus, the farm managers should provide a scientific mix of nutrients to improve cattle immunity, keep the environment clean, and disinfect regularly. Collectively, the control of E. bieneusi transmission in cattle is of importance for economic and public health., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interest or personal relationship that influenced the work reported in this study., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Giardia duodenalis has a wide range of host species and is a common causative agent of diarrheal disease in humans and animals. This study conducted a systematic review and meta-analysis to evaluate the pooled prevalence of Giardia among dogs in China. We extracted 33 studies related to the prevalence of G. duodenalis in dogs, with samples taken from 2001 to 2021. The random-effect model was used to calculate pooled prevalence estimates with 95% confidence intervals, and the analyzed data were from 14 provinces in China. The estimated overall prevalence of G. duodenalis among dogs in China was 11.2%. The prevalence of Giardia was significantly higher in Northwestern China (35.7%) than in other regions. The prevalence in 2010 or later (11.8%) was significantly higher than in 2010 or before (6.9%). The estimated prevalence detected by microscopy (9.3%) was lower than molecular (12.3%) and serological (14.3%) ones. The prevalence was higher in dogs <1 year of age (12.2%) than that >1 year (5.4%). Among the genotype groups, the positive rate of assemblage A (5.2%) was significantly higher than that of other assemblages. Depending on the dog' type, the prevalence of G. duodenalis in stray dogs (3.5%) was lower than that in pet dogs (6.7%) and intensively breeding dogs (11.8%). In addition, no correlation was found between Giardia positive rate and the dogs' gender ( p  > 0.05). We also analyzed the effects of different geographic factor subgroups (longitude, latitude, precipitation, temperature, humidity, and altitude) on the prevalence of G. duodenalis in dogs in China. The results showed that giardiasis was widespread in dogs in China. It is suggested that corresponding control scheme and effective management measures should be formulated and applied to reduce the transmission of G. duodenalis according to the difference in geographical conditions in different areas.

Toxoplasmosis is a zoonotic disease caused by Toxoplasma gondii, which is widespread in warm-blooded animals and humans. Currently, many studies regarding T. gondii infection in sheep have been published worldwide. However, there is no meta-analysis of sheep infection in China. In this study, five databases were used to retrieve articles related to T. gondii in China. A total of 59 studies from 1987 to June 30, 2020, have been included. We estimated that the combined prevalence of T. gondii in the selected period was 8.5% (3197/28,099). In the analysis of publication year, the lowest positive rate after 2010 was 7.4% (1883/17,313). Geographically, the highest prevalence of T. gondii in sheep was recorded in Southwest China 19.2% (490/2080). Analysis according to age showed that the prevalence of infection in sheep older than 12 months was significantly (P < 0.05) higher than that in younger animals. The prevalence of T. gondii in sheep farmed by farmers was 7.2% (566/6336), which was higher than 5.3% (660/3121) of large-scale farming, suggesting a role for the feeding and husbandry. We also analyzed the impact of different geographic and climatic factors on the prevalence of T. gondii infection in sheep. The results showed that the prevalence was higher in low altitude, warm, humid, and high rainfall areas. We suggest that appropriate control programs should be formulated according to the differences in reproduction patterns and geographical conditions in different regions to reduce the prevalence of T. gondii among sheep in China., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Toxoplasma gondii and Chlamydia are common protozoan pathogens, which can pose health risks to people around the world and cause considerable economic losses. Although information on the seroprevalence of T. gondii and Chlamydia in chickens can be found in China, knowledge on the infection of these two diseases in rural chickens, ducks, and geese is limited. Therefore, blood samples from 377 chickens, 268 ducks, and 379 geese were taken from rural areas in seven cities in northeastern China, and their seropositivity was analyzed by the indirect hemagglutination antibody (IHA) test with a cutoff titer of 1:64. The overall seroprevalence of T. gondii and Chlamydia was 10.6% and 21.0%, respectively. Moreover, the free-range poultry (20.75% and 30.55%) have significantly higher seroprevalences than caged poultry (5.47% and 15.66%) ( p  < 0.001). Moreover, the seroprevalence of T. gondii in older and younger poultry was found to be 5.48% and 12.89%, and those in Chlamydia were 23.53% and 15.16%, respectively. There were significant differences between different ages ( p  < 0.05). But regarding the prevalence of both, it is not clear in this way which one is the prevalence for younger and older for each specific pathogen. Logistic regression analysis suggested that geography were considered as a risk factor for T. gondii infection in this study. Our study is the first report on the seroprevalence of T. gondii and Chlamydia in poultry in rural areas of Jilin Province, China. These data reflect that T. gondii and Chlamydia are widespread in poultry in northeastern China, leading to a risk of infection in human health. Therefore, the prevention and control of Toxoplasma and Chlamydia infection in poultry, other animals, and humans should be strengthened.

Heat storage (Q) is an important component of the near-surface energy balance, and has been increasingly considered in recent energy balance studies. Studies have revealed that the hysteresis of heat storage was always been ignored, which leaded to the underestimation of heat storage proportion in energy balance. So, for further understanding the role of hysteresis effect in forestry heat storage, an observation experiment of heat storage in forestry of Pinus sylvestris var. mongolica Litv forestry - a common species in northern China - was conducted. Heat storage in the atmosphere beneath canopy, in the canopy biomass, and in the soil above a soil heat-flow plate were monitored continuously, to determine the distribution of stored heat, and solar radiation was simultaneously monitored to verify the hysteresis of heat storage versus radiation. Seasonal variations were separately analyzed to further clarify phenological effect on hysteresis. Correlation relationship was tested of lag time and underestimated energy versus climatic factors and physiological characteristics, for clarifying the reasons that resulting in hysteresis differences under different experimental day. The main results were as follows: (1) Hysteresis exists in heat storage and the lag time was 3.79 h in our study area; (2) The evaluation of hysteresis is crucial to avoid an underestimation of heat storage. Correction of lag time increases the heat storage proportion in R from 3.78% to 8.48%; (3) Increasing of air temperature and humility daily differences will enhance the underestimated energy. High radiation condition will weak the underestimation on heat storage and short the lag time. Soil moisture and leaf area index were not effect energy hysteresis significantly in sandy vegetation. Climatic factors were the main reason that resulting in the differences of hysteresis. This study helps to improve understanding energy transmitting in canopy and offering a new view in solving surface energy imbalance., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Since the establishment of blown sand physics, surface roughness has been widely used in current research to indicate the ability of a surface to resist wind erosion and to evaluate the windproof effect of protective measures. However, since the calculation of surface roughness can result in different values and its applicability is poor, there are disadvantages to its use. Therefore, it is proposed that the boundary layer displacement thickness should be used rather than roughness as an indicator to solve such problems. To analyze the new indicator's accuracy and applicability when evaluating the effect of protective measures, a wind tunnel simulation experiment on a typical mechanical protection measure commonly used for sand control in China was conducted. Indicators of roughness and boundary layer displacement thickness were compared in evaluating the windproof performance of a Salix psammophila sand barrier of differing heights, side lengths, and porosities. The wind speed acceleration rate and effective protection area, which can directly reflect the protective effect of a sand barrier, were analyzed as evaluation criteria. The results show that roughness can only reflect the influence of height on the windbreak effect of sand barriers, whereas the boundary layer displacement thickness accurately showed the influence of height, side length, and porosity on the windproof effect of the sand barriers. Compared with roughness, the boundary layer displacement thickness was more strongly correlated with the effective protection area. Therefore, the boundary layer displacement thickness, rather than roughness, should be used as a new indicator when evaluating the windproof effect of protective measures.

Due to their simple layout and adaptability to various environments, straw checkerboards are widely used to control windblown sand in China. To fully understand the wind proofing and sand-fixing benefits of different board specifications, and to determine the restorative effects of straw checkerboard, we tested different sizes of checkerboard, determined their performance as a windbreak and in trapping shifting sand, and constructed models based on wind tunnel tests, enabling the wind speed flow field to be analysed. We also sampled the soil in areas where straw checkerboards had been established for several years and analysed the trends in soil physical and chemical properties over time. We found that all sizes of straw checkerboard effectively reduced the wind speed near the surface and formed a protected area, with the best protective effect achieved for a one-meter board. All sizes of straw checkerboard effectively intercepted windblown sand to form surface accumulation, with the one-meter board again showing the best performance. The use of a straw checkerboard also effectively improved the physical and chemical properties of soil and promoted ecological restoration. These results indicate that straw checkerboards are a low-cost engineering measure that could play an important role in desertification control and the ecological restoration of sandy land ecosystems.

Objectives: To investigate the development and the health of reproductive organs of male children and juvenile between the Meng and the Han nationality in the Meng nationality area., Methods: Male juvenile(4-18 years old) of the Meng nationality (n = 2,315) and the Han nationality (n = 2,832) were divided into four age groups. Height, weight, length and perimeter of penis, volume of left and right testis and reproductive organs illness were examined., Results: In 13-18 years group, the developmental speed of reproductive organs was faster in Mongolia male juvenile than that in the Han nationality (P < 0.02). After 13 years old, the developmental speed of reproductive organs of male living in town is faster than that in the country (P < 0.05). Illness of male reproductive organs was common such as hernia, varicocle etc., Conclusions: There was difference of developmental status and the prevalence rate of reproductive organs of male children and juvenile between the Meng and the Han nationality.