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Abstract Despite a rapid expansion of Porcine reproductive and respiratory syndrome virus (PRRSV) sublineage 8.7 over recent years, very little is known about the patterns of virus evolution, dispersal, and the factors influencing this dispersal. Relying on a national PRRSV surveillance project established over 20 years ago, we expand the available genomic data of sublineage 8.7 from China. We perform independent interlineage and intralineage recombination analyses for the entire study period, which showed a heterogeneous recombination pattern. A series of Bayesian phylogeographic analyses uncover the role of Guangdong as an important infection hub within Asia. The spatial spread of PRRSV is highly linked with a composite of human activities and the heterogeneous provincial distribution of the swine industry, largely propelled by the smaller-scale Chinese rural farming systems in the past years. We sequence all four available modified live vaccines (MLVs) and perform genomic analyses with publicly available data, of which our results suggest a key “leaky” period spanning 2011–2017 with two concurrent amino acid mutations in ORF1a 957 and ORF2 250. Overall, our study provides an in-depth overview of the evolution, transmission dynamics, and potential leaky status of HP-PRRS MLVs, providing critical insights into new MLV development.

In recent years, NADC34-like strains of porcine reproductive and respiratory syndrome virus have gradually emerged as mainstream strains on Chinese pig farms. These strains have high mutation rates and can recombine with local strains, representing great challenges to prevention and control efforts. Previously, a new recombinant NADC34-like subtype strain was isolated in our laboratory. Herein, we evaluated the cross-protective effect of the VR2332 modified live virus (MLV) against the novel NADC34-like recombinant strain using the immune challenge protection test in piglets and sows. The results revealed that immunization with the vaccine in piglets significantly reduced viremia, lung damage and stimulated the production of PRRSV-N antibodies. In the sow challenge experiment, one abortion and one death were recorded in the positive control group, and the survival rate of offspring was only 25%. However, there were no sow deaths or abortions in the immunization group during the experiment, and the average piglet survival rate was high at 76.5%. In general, the VR2332 MLV confers a certain extent of cross-protection against the NADC34-like recombinant strain, providing an effective reference and guidance for prevention and control efforts and clinical vaccine use.

IntroductionGetah virus (GETV) is a multi-host virus found in pigs, horses, and blue foxes. Clinically, GETV can cause fever, diarrhea, and reproductive disorders in pigs, representing significant threats to pig breeding. At present, few studies have examined the pathogenicity of GETV in pigs of different ages.MethodsIn the present study, a new strain, named GETV-QJ, was isolated from clinically ill pigs, and whole genome sequencing analysis was performed. Besides the pathogenicity of piglets and pregnant sows of this strain was further studied.Resultsthe results illustrated that the strain belonged to group III. The strain had 93.6%–96.3% homology with other subtypes, and its homology with the same subtype strain ranged 96.5%–99%. Further studies on the pathogenicity of the virus indicated that this strain caused severe diarrhea, fever, and intestinal and lung damage in 7-day-old piglets, resulting in their death. The piglet survival rate was 0%. In pregnant sows, this strain did not cause fever, death, or abortion, but it induced viremia, which affected the farrowing performance of sows and led to reduced piglet survival.DiscussionIn this study, we isolated a highly virulent group III and comprehensively established a pathogenic model of GETV in piglets and sows, providing a reference and guidance for the prevention and control of this infection.

ABSTRACT Porcine reproductive and respiratory syndrome viruses (PRRSVs) exhibit high mutability and recombination, posing challenges to their immunization and control. This study isolated two new PRRSV strains, GD-7 and GX-3, from samples collected in Guangdong and Guangxi in 2023. Whole-genome sequencing, along with phylogenetic and recombination analyses, confirmed that GD-7 and GX-3 are natural novel recombinant strains of NADC30 PRRSV. Moreover, we established a pathogenicity model for piglets and sows based on the two isolates. The results of piglet pathogenicity revealed that both GD-7 and GX-3 caused clinical symptoms such as fever, loss of appetite, depression, and slow weight gain. Moreover, we observed that the mortality rate of GD-7-inoculated group piglets was 33.3%, which was similar to that of piglets infected with other highly pathogenic PRRSV strains and exceeded the mortality rate of most NADC30-like PRRSV. In pregnant sow models, the survival rate of sows in the GD-7 group was 75%, in contrast to the GX-3 group, where no sow mortality was observed, and both strains resulted in abortion, mummified fetuses, and stillbirths. These results highlight the elevated pathogenicity of these recombinant strains in sows, with GD-7 mainly causing sows to abort, and GX-3 mainly causing sows to give birth to mummified fetuses. This study introduces two distinct clinical recombinant PRRSV strains that differ from the prevalent strains in China. This research furthers our understanding of the epidemiology of PRRSV and underscores the significance of ongoing monitoring and research in the face of evolving virus strains. Moreover, these discoveries act as early warnings, underscoring the necessity for active control and immunization against PRRSV.IMPORTANCESince the discovery of NADC30-like PRRSV in China in 2013, it has gradually become the dominant strain of PRRSV in China. NADC30-like PRRSV exhibits high recombination characteristics, constantly recombining with different strains, leading to the emergence of numerous novel strains. Of particular importance is the observation that NADC30-like PRRSV with different recombination patterns exhibits varying pathogenicity, which has a significant impact on the pig farming industry. This emphasizes the necessity of monitoring and responding to evolving PRRSV strains to develop effective immunization and control strategies. In this paper, we conducted pathogenicity studies on the isolated NADC30-like PRRSV and analyzed the differences in the genomes and pathogenicity of the different strains by recording clinical symptoms, temperature changes, detoxification tests, and changes in viremia and histopathology in infected pigs. This was done to provide a theoretical basis for the epidemiological situation and epidemic prevention and control of PRRSV.

In recent years, the Ordos Basin has undergone a reevaluation, transitioning from a perception of a single block to a focus on understanding the influence of multiple stages and fault systems on hydrocarbon accumulation. This study utilizes the latest 3D seismic and drilling data alongside a theoretical model of strike-slip fault to analyze fault geometry and kinematics in the Xunyi-Yijun area of the basin's southern region. The mechanisms of fault formation are predicted and the related impacts on the formation and accumulation of deep carbonate rocks are also discussed. The results indicate the presence of three fault systems in the Xunyi-Yijun area, with decoupling between deep and shallow layers. The Lower Paleozoic strike-slip faults exhibit distinct characteristics, including high vertical structure, dip swing, and a "flower-shaped" structure in the section. The faults display "compression shear in the northwest, tension shear in the center, and segmental deformation on trunk fractures" on their planes.Moreover, the Lower Paleozoic strike-slip faults experienced two stages of tectonic activities with greater intensity observed from the Late Ordovician to the Silurian, marking the primary period of fault development. The activity intensity during the Middle to Late Permian was relatively weaker, with faults exhibiting inherited strike-slip characteristics. These faults formed two groups, one with a NE strike and the other with a NW strike. Additionally, during the second stage of the Caledonian period, ocean subduction and closure lead to stress being transferred to the basin interior. It is believed that the NE and NW strike basement weak zones existed in the southern Ordos Basin. As a result, the Lower Paleozoic strike-slip fault system likely formed due to the activation of oblique compression. This fault system has the potential to enhance the physical properties of deep carbonate reservoirs and create high-quality karst or tectonic fracture reservoirs in the Xunyi-Yijun area. Moreover, The formation of the "upper source and lower reservoir-lateral source and lateral reservoir" combination along the strike-slip fault belt is an area of interest for deep oil and gas exploration in the Xunyi-Yijun region.

Porcine circoviruses disease (PCVD), caused by porcine circovirus (PCVs), is an important swine disease characterized by porcine dermatitis, nephrotic syndrome and reproductive disorders in sows. However, diseases caused by PCV2, PCV3, or PCV4 are difficult to distinguish, so a simple, rapid, accurate and high-throughput diagnostic and identification method is urgently needed to differentiate these three types. In this study, specific primers and probes were designed based on the conserved region sequences of the Rep gene of PCV2, and the Cap gene of PCV3 and PCV4. A multiplex qPCR assay was developed and optimized that the limit of detection concentration could reach as low as 3.8 copies/μL, with all correlation coefficients (R2) exceeding 0.999. Furthermore, the method showed no cross-reaction with other crucial porcine viral pathogens, and both intra-repeatability and inter-reproducibility coefficients of variation were below 2%. The assay was applied to the detection of 738 pig samples collected from 2020 to 2021 in Guangdong Province, China. This revealed positive infection rates of 65.18% for PCV2, 29.27% for PCV3, and 0% for PCV4, with a PCV2/PCV3 co-infection rate of 23.17%. Subsequently, complete genome sequences of 17 PCV2 and 4 PCV3 strains were obtained from the above positive samples and pre-preserved positive circovirus samples. Nucleotide sequence analysis revealed that the 17 PCV2 strains shared 96.7–100% complete nucleotide identity, with 6 strains being PCV2b and 11 strains being PCV2d; the 4 PCV3 strains shared 98.9–99.4% complete nucleotide identity, with 2 strains being PCV3a-1 and 2 strains being PCV3b. This research provides a reliable tool for rapid PCVs identification and detection. Molecular epidemiological investigation of PCVs in pigs in Guangdong Province will help us to understand PCV2 and PCV3 epidemiological characteristics and evolutionary trends.

The mechanism of the combined process of ion beam sputtering (IBS) and HF acid etching on the chemical structure defects of fused silica and its laser damage resistance performance were investigated in this paper. During the removal process of surface material, the sputtering effect causes lattice atoms to flee their native space locations, and a large amount of unsaturated chemical structures are produced on the silica surface, which improves the chemical activity of Si and O atoms, accelerates the chemical reaction process between surface atoms and water molecules, increases the content of hydroxyl groups (OH-) in the shallow layer, and enhances the photothermal weak absorption intensity. However, the increase in hydroxyl content weakens the binding strength of silicon–oxygen bonds, destroys the spatial network structure of silica bulk, and reduces its mechanical strength, resulting in a decrease in its laser damage resistance performance. The paper reveals for the first time the mechanism by which IBS changes the structure characteristics of silica material, accelerates the surface hydroxylation process, and thereby reduces the laser damage resistance performance. This work provides technical guidance for effectively suppressing chemical structure defects on silica surfaces and improving the laser damage resistance performance of optical components under high-flux laser irradiation.

Newcastle disease (ND) is one of the diseases that seriously damage the health of poultry and is widely prevalent worldwide. It is characterized by high fever, respiratory distress, dysentery, neurological disorders, and mucosal hemorrhage, seriously threatening the growth and reproduction of poultry and production of poultry meat. Newcastle disease is caused by Newcastle disease virus (NDV), which has been prevalent for nearly 100 years and can infect more than 200 species of poultry, including chickens, ducks, geese and pigeons. It has many genotypes, and the variable genotypes bring great difficulties to the prevention and control of ND. The migration of birds plays an important role in the cross-border spread of the virus, resulting in Newcastle disease outbreaks in various regions of China, bringing huge economic losses to the poultry industry and seriously restricting the healthy development of the poultry breeding industry. In view of the wide distribution of NDV and the strong host mobility, it makes an important epidemic disease threatening the poultry breeding industry. Therefore, to understand the prevalence of NDV in China, the study analyzes its molecular epidemiology and the spatial and temporal distribution of each genotype, and it is found that ND in China is mainly distributed in southern China, such as Guangxi and Guangdong, eastern China, such as Jiangsu and Anhui, and northwestern China, such as Shaanxi and Gansu. The highly pathogenic Class Ⅱ strains isolated from these regions include multiple genotypes, with genotype Ⅱ and genotype Ⅶ strains being the main prevalent strains. The collation and analysis of NDV prevalence data provide reference data for epidemic prevention control, and vaccine development.

Organic farming in extensive production regions, such as the Canadian prairies have a particularly difficult challenge of replenishing soil reserves of phosphorus (P). Organic grains are exported off the farm while resupply of lost P is difficult due to limited availability of animal manures and low solubility of rock organic fertilizers. As a result, many organic farms on the prairies are deficient in plant-available P, leading to productivity breakdown. A portion of the solution may involve crop genetic improvement. A hypothetical ‘catch and release’ wheat ideotype for organic production systems is proposed to (i) enhance P uptake and use efficiency but (ii) translocate less P from the vegetative biomass into the grain. Root traits that would improve P uptake efficiency from less-available P pools under organic production are explored. The need to understand and classify ‘phosphorus use efficiency’ using appropriate indices for organic production is considered, as well as the appropriate efficiency indices for use if genetically selecting for the proposed ideotype. The implications for low seed P and high vegetative P are considered from a crop physiology, environmental, and human nutrition standpoint; considerations that are imperative for future feasibility of the ideotype.

The effects of increased nitrogen (N) deposition on desert ecosystems have been extensively studied from a plant community perspective. However, the response of soil microbial communities, which play a crucial role in nutrient cycling, to N inputs and plant community types remains poorly understood. In this study, we conducted a two-year N-addition experiment with five gradients (0, 10, 30, 60, and 120 kg N ha−1 year−1) to evaluate the effect of increased N deposition on soil bacterial and fungal communities in three plant community types, namely, Alhagi sparsifolia Shap., Karelinia caspia (Pall.) Less. monocultures and their mixed community in a desert steppe located on the southern edge of the Taklimakan Desert, Northwest China. Our results indicate that N deposition and plant community types exerted an independent and significant influence on the soil microbial community. Bacterial α-diversity and community dissimilarity showed a unimodal pattern with peaks at 30 and 60 kg N ha−1 year−1, respectively. By contrast, fungal α-diversity and community dissimilarity did not vary significantly with increased N inputs. Furthermore, plant community type significantly altered microbial community dissimilarity. The Mantel test and redundancy analysis indicated that soil pH and total and inorganic N (NH4+ and NO3−) levels were the most critical factors regulating soil microbial communities. Similar to the patterns observed in taxonomic composition, fungi exhibit stronger resistance to N addition compared to bacteria in terms of their functionality. Overall, our findings suggest that the response of soil microbial communities to N deposition is domain-specific and independent of desert plant community diversity, and the bacterial community has a critical threshold under N enrichment in arid deserts.

Abstract Background Pain relief for patients in the intensive care unit (ICU) can improve treatment outcomes and reduce the burden on doctors and nurses. This study aims to report the clinical analgesic and sedative effects of nalbuphine and sufentanil on ICU patients. Methods This study retrospectively analyzed the medical records of 87 critically ill patients who received nalbuphine or sufentanil infusion in the ICU, including demographic data, diagnosis, Acute Physiology and Chronic Health Evaluation (APACHE) II, Critical Care Pain Observation Tool (CPOT), Richmond Agitation-Sedation Scale (RASS), systolic and diastolic blood pressure, heart rate and blood oxygen saturation (SpO2). The primary outcomes of this study were CPOT and RASS scores. The secondary outcomes were hemodynamic changes, including systolic blood pressure, diastolic blood pressure, heart rate, and SpO2. The adverse events recorded during pain management, such as hypoxemia, respiration depression and bradycardia, were also collected and analyzed. Results None of the patients in both groups experienced episode of hypoxemia, respiration depression and bradycardia. However, age-stratified analyses showed that nalbuphine has a better analgesic effect than sufentanil for patients aged ≤ 60 (P 60 ( P

It remains uncertain how different N inputs as synthetic fertilizer or manure and irrigation types affect nitrous oxide (N2O) production and effluxes in the subsurface. A field trial was carried out in 2016 to evaluate the impacts of conventional urea, animal manure, and a 50/50 mix of urea and manure on N2O production/effluxes from a cotton (Gossypium hirsutum L.) field under flood or drip irrigation in northwestern China. Soil N2O concentrations were monitored at 5, 15, 30, and 60 cm depths to assess the production and diffusion rates of N2O in the soil profile. The results showed that N2O concentrations in 0–60 cm ranged between 221 and 532 nL L−1 and averaged 344 nL L−1, which was generally lower compared to other studies in the same region. Manure and flood irrigation significantly increased N2O production at 0–5 cm and 5–15 cm, respectively. That is, the effects of nitrogen management and irrigation types on the N2O production of the profile were reflected in the surface layers and subsurface layers, respectively. All N2O production occurred in the 0–15 cm layer, with the 0–5 cm depth contributing 87%–100% of the surface emissions. The response discrepancy of N2O production/diffusion to irrigation and nitrogen management in different soil depths should be fully considered in developing agricultural N2O emission reduction measures.

Soil nutrients are vital for plant growth and survival and present a crucial role in terrestrial function and productivity. However, little is known about the effect mechanism of groundwater table on soil nutrients in an arid desert ecological system. This study investigated the impacts of groundwater depth on the concentrations of soil organic carbon (C), available nitrogen (N), phosphorus (P), and potassium (K) at shallow groundwater depths (0.4, 0.8, 1.2, 1.8, and 2.2 m) and field deep groundwater depths (2.5, 4.5, and 11.0 m) in a desert-oasis ecotone in Central Asia in 2015 and 2016. Soil nitrate-N, inorganic-N, soil available P, and K concentrations were significantly affected by shallow and field deep groundwater. Groundwater depths did not alter soil ammonium-N concentration. Soil organic C concentration was influenced by field deep groundwater depth. Structural equation model showed that groundwater depth directly affected soil nitrate-N and K concentrations and indirectly altered the soil inorganic-N, soil organic C and available P concentrations in shallow groundwater. Moreover, groundwater depth directly influenced soil nitrate-N and soil organic C, available P and K concentrations and indirectly affected soil inorganic-N concentration in deep groundwater. Hence, groundwater depth should be considered one of the most critical environmental factors affecting soil nutrient variation in an arid desert. This study provides new insights into the soil nutrient variation under a declining groundwater depth in a hyper-arid ecosystem.

ObjectivesIn order to explore the laws of the emergency surfacing motion of submarines, a simplified model of propeller volume force was used to carry out the numerical simulation of submarine emergency surfacing motion at different speeds.MethodsNumerical simulations of the underwater fixed depth, ascent and surfacing of the hull were carried out, and submarine buoyancy under different speeds was compared and analyzed by matching the screw rotation speed with the speed of the submarine, as well as its ascent time and attitude.ResultsAs the results show, the faster the rotation speed, the shorter the time for the submarine to gain steady speed and maintain fixed depth underwater. Regardless of the trim angle or heeling angle, the time when the angle changes for the first time and that when the peak occurs show a trend of reduction although the rotational speed increases. At the same time, with the increase in rotation speed, the fluctuation time of trim angle increases, while the fluctuation time of heeling angle decreases.ConclusionsThe relevant calculation methods and results of this study can provide practical references for research on submarine emergency surfacing motion.

Abstract Background In industrial fermentation, pH fluctuation resulted from microbial metabolism influences the strain performance and the final production. The common way to control pH is adding acid or alkali after probe detection, which is not a fine-tuned method and often leads to increased costs and complex downstream processing. Here, we constructed an intelligent pH-sensing and controlling genetic circuits called “Genetic pH Shooting (GPS)” to realize microbial self-regulation of pH. Results In order to achieve the self-regulation of pH, GPS circuits consisting of pH-sensing promoters and acid-/alkali-producing genes were designed and constructed. Designed pH-sensing promoters in the GPS can respond to high or low pHs and generate acidic or alkaline substances, achieving endogenously self-responsive pH adjustments. Base shooting circuit (BSC) and acid shooting circuit (ASC) were constructed and enabled better cell growth under alkaline or acidic conditions, respectively. Furthermore, the genetic circuits including GPS, BSC and ASC were applied to lycopene production with a higher yield without an artificial pH regulation compared with the control under pH values ranging from 5.0 to 9.0. In scale-up fermentations, the lycopene titer in the engineered strain harboring GPS was increased by 137.3% and ammonia usage decreased by 35.6%. Conclusions The pH self-regulation achieved through the GPS circuits is helpful to construct intelligent microbial cell factories and reduce the production costs, which would be much useful in industrial applications.

Few studies have investigated how the reclamation of the desert to cropland affects soil nitrous oxide (N2O) emissions. A study site was initiated in 2005 at the southern Taklimakan Desert by establishing four fields along the desert−oasis ecotone. Three fields were reclaimed as croplands for continuous cotton (Gossypium hirsutum L.) production and received (1) high, (2) low, and (3) no fertilizer inputs and the fourth field remained as a native desert. Static-chamber monitoring of N2O flux was conducted from April 2019 to March 2021. N2O emissions occurred in cropland mainly after drip fertigation during the growing season. The two−year N2O emissions in the desert, no fertilizer, low fertilizer, and high fertilizer were 248, 670, 2232, and 3615 g N ha−1, respectively. The native desert was a weak source of N2O emissions, with the non−growing season emissions accounting for 66% of the annual emissions. N2O emissions from farmland mainly occurred over the growing season, accounting for 73−98% of the total annual emissions. The N2O flux was positively related to soil NO3−−N concentration and soil water−filled pore space (WFPS), highlighting the importance of soil N availability and moisture in affecting N2O emissions in extremely arid areas. Our results demonstrate that land reclamation from the desert to cropland significantly increased N2O emissions due to high nutrient inputs. Thus, appropriate fertilizer management in the reclaimed land is essential for maintaining yield, improving soil quality, and reducing N2O emissions for continuous cotton production.

The technology of intelligent IoT and ubiquitous access lead to the change of the learning mode.The traditional mobile phone assisted teaching mode just simply transplants some contents of classroom teaching to the Internet terminal,which does not give full play to the flexibility and interest of the mobile intelligent terminal.Based on the fragmentation of learning content and the innovation of mobile communication technology,a ubiquitous learning theory oriented to auxiliary teaching was proposed,which made full use of the advantages of fragmentation time and mobile learning and made fragmented learning possible.Then,the feasibility of game assisted teaching was demonstrated,including the collaborative learning network,situational cognitive theory and ubiquitous learning.In addition,a learner-centered game assisted teaching model was proposed,which consists of three parts including game assisted teaching strategy,learner and teaching design model.It pays more attention to the realization of expected teaching objectives and the maintenance of learning stickiness.Finally,the feasibility and effectiveness of ubiquitous learning theory were verified by the experimental results of two courses of mobile phone assisted teaching,which makes mobile game assisted teaching a useful supplement to traditional classroom teaching.

Nutrients are vital for plant subsistence and growth in nutrient-poor and arid ecosystems. The deep roots of phreatophytic plants are necessary to access groundwater, which is the major source of nutrients for phreatophytes in an arid desert ecosystem. However, the mechanisms through which changes in groundwater depth affect nutrient cycles of phreatophytic plants are still poorly understood. This study was performed to reveal the adaptive strategies involving the nutrient use efficiency (NUE) and nutrient resorption efficiency (NRE) of desert phreatophytes as affected by different groundwater depths. This work investigated the nitrogen (N), phosphorus (P), and potassium (K) concentrations in leaf, stem, and assimilating branch, as well as the NUE and NRE of the phreatophytic Alhagi sparsifolia. The plant was grown at groundwater depths of 2.5, 4.5, and 11.0 m during 2015 and 2016 in a desert-oasis transition ecotone at the southern rim of the Taklimakan Desert in northwestern China. Results show that the leaf, stem, and assimilating branch P concentrations of A. sparsifolia at 4.5 m groundwater depth were significantly lower than those at 2.5 and 11.0 m groundwater depths. The K concentrations in different tissues of A. sparsifolia at 4.5 m groundwater depth were significantly higher than those at 2.5 and 11.0 m groundwater depths. Conversely, the NRE of P in A. sparsifolia was the highest among the three groundwater depths, while that of K in A. sparsifolia was the lowest among the three groundwater depths in 2015 and 2016. The N concentration and NUE of N, P, and K in A. sparsifolia, however, were not influenced by groundwater depth. Further analyses using structural equation models showed that groundwater depth had significant effects on the P and K resorption of A. sparsifolia by changing soil P and senescent leaf K concentrations. Overall, our results suggest groundwater depths affect P and K concentrations and resorption but not their utilization in a desert phreatophyte in its hyper-arid environment. This study provides a new insight into the phreatophytic plant nutrient cycle strategy under a changing external environment in a hyper-arid ecosystem.

Nitrogen (N) addition is an important nutrient strategy for alpine grassland in northwestern China to improve productivity for livestock needs. A field experiment was conducted in a semi-arid alpine grassland in northwestern China to investigate the effect of N addition rates on soil N2O emissions over the growing seasons of 2017 and 2018. Treatments included six N addition rates (0, 10, 30, 60, 120, 240 kg N ha−1 y−1), which were applied before each growing season. The N2O fluxes increased with N addition rates and showed different episodic changes between the two growing seasons. In 2017, the maximum N2O flux rate occurred within 2 weeks following N addition. In 2018, however, the maximum N2O flux rate occurred later in the growing season due to a heavy rainfall event. Growing season cumulative N2O emissions ranged between 0.32 and 1.11 kg N ha−1, and increased linearly with N addition rates. Increasing N addition rates over 60 kg N ha−1 yr−1 did not further increase plant above-ground biomass. The inter-annual variability of N2O flux suggests the importance of soil moisture in affecting N2O emissions. It is particularly important to avoid over-applying N nutrients beyond plant needs to reduce its negative effect on the environment while maintaining livestock productivity. The N2O flux rate increased with soil dissolved organic carbon (DOC) and soil pH. These results suggest the optimal N addition rate to the livestock grassland in this region should be 60 kg N ha−1 yr−1.

This paper describes data of nitrous oxides (N2O) emissions from open-field and greenhouse systems in Chinese vegetable production. The data also describes the potential soil and management factors to identify the effective measures to mitigate N2O emissions. The data were collected from 21 peer-reviewed papers, covering 153 N2O emission field measurements as affected by fertilizer nitrogen (N) management. This data were subjected to meta-analysis for a comprehensive assessment on N2O emission and applied N based emission factor in Chinese vegetable production. Keywords: Chinese vegetable fields, Meta-analysis, Nitrous oxide emission, Emission factor

Application of inorganic nitrogen (N) fertilizer and manure can increase nitrous oxide (N2O) emissions. We tested the hypothesis that increased N2O flux from soils amended with manure reflects a change in bacterial community structure and, specifically, an increase in the number of denitrifiers. To test this hypothesis, a field experiment was conducted in a drip-irrigated cotton field in an arid region of northwestern China. Treatments included plots that were not amended (Control), and plots amended with urea (Urea), animal manure (Manure) and a 50/50 mix of urea and manure (U+M). Manure was broadcast-incorporated into the soil before seeding while urea was split-applied with drip irrigation (fertigation) over the growing season. The addition treatments did not, as assessed by nextgen sequencing of PCR-amplicons generated from rRNA genes in soil, affect the alpha diversity of bacterial communities but did change the beta diversity. Compared to the Control, the addition of manure (U+M and Manure) significantly increased the abundance of genes associated with nitrate reduction (narG) and denitrfication (nirK and nosZ). Manure addition (U+M and Manure) did not affect the nitrifying enzyme activity (NEA) of soil but resulted in 39–59 times greater denitrifying enzyme activity (DEA). In contrast, urea application had no impact on the abundances of nitrifier and denitrifier genes, DEA and NEA; likely due to a limitation of C availability. DEA was highly correlated (r = 0.70–0.84, P < 0.01) with the abundance of genes narG, nirK and nosZ. An increase in the abundance of these functional genes was further correlated with soil NO3−, dissolved organic carbon, total C, and total N concentrations, and soil C:N ratio. These results demonstrated a positive relationship between the abundances of denitrifying functional genes (narG, nirK and nosZ) and denitrification potential, suggesting that manure application increased N2O emission by increasing denitrification and the population of bacteria that mediated that process.

Ecological stoichiometry is an important aspect in the analysis of the changes in ecological system composition, structure, and function and understanding of plant adaptation in habitats. Leaf carbon (C), nitrogen (N), and phosphorus (P) concentrations in desert phreatophytes can be affected by different depths of groundwater through its effect on the adsorption and utilization of nutrient and plant biomass. We examined the biomass, soil organic C, available (mineral) N, and available P, and leaf C, N, and P concentrations of Alhagi sparsifolia grown at varying groundwater depths of 2.5, 4.5, and 11.0 m in 2015 and 2016 growing seasons in a desert-oasis ecotone in northwest China. The biomass of A. sparsifolia and the C, N, and P concentrations in soil and A. sparsifolia showed different responses to various groundwater depths. The leaf P concentration of A. sparsifolia was lower at 4.5 m than at 2.5 and 11.0 m likely because of a biomass dilution effect. By contrast, leaf C and N concentrations were generally unaffected by groundwater depth, thereby confirming that C and N accumulations in A. sparsifolia were predominantly determined by C fixation through the photosynthesis and biological fixation of atmospheric N2, respectively. Soil C, N, and P concentrations at 4.5 m were significantly lower than those at 11.0 m. Leaf P concentration was significantly and positively correlated with soil N concentration at all of the groundwater depths. The C:N and C:P mass ratios of A. sparsifolia at 4.5 m were higher than those at the other groundwater depths, suggesting a defensive life history strategy. Conversely, A. sparsifolia likely adopted a competitive strategy at 2.5 and 11.0 m as indicated by the low C:N and C:P mass ratios. To our knowledge, this study is the first to elucidate the variation in the C, N, and P stoichiometry of a desert phreatophyte at different groundwater depths in an arid ecosystem.

An experimental study that investigates the behavior of stone slabs strengthened in fixure with near surface mounted (NSM) technique using screw-thread steels and carbon fiber-reinforced polymer (CFRP) bars is presented. A total of ten full-scale stone slabs were tested under a four-point bending loading to investigate the effect of groove dimension, reinforcement ratios, and reinforcement materials on the flexural performance of stone slabs. The test results included failure characteristics, yield and ultimate capacities, deflection of midspan, and cracking behavior of stone slabs. The test results indicate that with the increase of groove height and groove width, cracking load and middeflection decrease by 6.4%–14.18%; however, failure load and middeflection increase by 4.7%–41.2%. Cracking load, failure load, and failure displacement of stone slabs adopting NSM screw-thread steels increased by 10.9%, 167%, and 617%, respectively, under the maximum reinforcement ratios of 0.629% over the control slab without NSM bars. Meanwhile, with the increase of reinforcement ratios, the failure mode transforms from brittle failure to ductile failure. The calculation results of strength are in agreement with the experimental results. Finally, it can be concluded that NSM CFRP bars are more effective than NSM screw-thread steels to improve flexural capacity with the same reinforcement ratios.

Caches play an important role in embedded systems to bridge the performance gap between fast processor and slow memory. And prefetching mechanisms are proposed to further improve the cache performance. While in real-time systems, the application of caches complicates the Worst-Case Execution Time (WCET) analysis due to its unpredictable behavior. Modern embedded processors often equip locking mechanism to improve timing predictability of the instruction cache. However, locking the whole cache may degrade the cache performance and increase the WCET of the real-time application. In this paper, we proposed an instruction-prefetching combined partial cache locking mechanism, which combines an instruction prefetching mechanism (termed as BBIP) with partial cache locking to improve the WCET estimates of real-time applications. BBIP is an instruction prefetching mechanism we have already proposed to improve the worst-case cache performance and in turn the worst-case execution time. The estimations on typical real-time applications show that the partial cache locking mechanism shows remarkable WCET improvement over static analysis and full cache locking.

Field experiments were conducted at two locations in Manitoba, Canada, to determine the effect of crop rotation, phosphorus (P) fertilization and tillage on grain yield and grain concentrations of Cd and Zn in durum wheat (Triticum durum L.). Compared to conventional tillage (CT), reduced tillage (RT) management decreased grain Cd and increased grain yield and grain Zn in half of the site-years. The type of preceding crops of spring wheat-flax or canola-flax had little influence. Rate and timing of P application had little effect on grain Cd, but increasing P rate tended to decrease grain Zn. No interactive effect was detected among tested factors. Grain Zn was not related to grain Cd, but positively to other nutrients such as Fe, Mn, P, Ca, K, and Mg. Both grain Zn and Fe correlated positively with grain protein content, suggesting protein may represent a sink for micronutrients. The study suggested that the tillage management may have beneficial effects on both grain yield and quality. Phosphorus fertilizer can remain available for subsequent crops and high annual inputs in the crop sequence may decrease crop grain Zn. Understanding the environment is important in determining the impact of agricultural management on agronomic and nutrient traits.

Organic farming in extensive production regions, such as the Canadian prairies have a particularly difficult challenge of replenishing soil reserves of phosphorus (P). Organic grains are exported off the farm while resupply of lost P is difficult due to limited availability of animal manures and low solubility of rock organic fertilizers. As a result, many organic farms on the prairies are deficient in plantavailable P, leading to productivity breakdown. A portion of the solution may involve crop genetic improvement. A hypothetical 'catch and release' wheat ideotype for organic production systems is proposed to (i) enhance P uptake and use efficiency but (ii) translocate less P from the vegetative biomass into the grain. Root traits that would improve P uptake efficiency from less-available P pools under organic production are explored. The need to understand and classify 'phosphorus use efficiency' using appropriate indices for organic production is considered, as well as the appropriate efficiency indices for use if genetically selecting for the proposed ideotype. The implications for low seed P and high vegetative P are considered from a crop physiology, environmental, and human nutrition standpoint; considerations that are imperative for future feasibility of the ideotype. [ABSTRACT FROM AUTHOR]

Inappropriate nitrogen fertilizer management for the intensive Chinese vegetable production has caused low N use efficiency (NUE), high reactive nitrogen (Nr) losses and serious environmental risks with limited yield increase. Innovative N management strategy is an urgent need to achieve sustainable vegetable production. This paper summarizes recent studies on Nr losses and identifies the limitations from Chinese vegetable production systems and proposes three steps for sustainable N management in Chinese vegetable production. The three N management steps include, but are not limited to, (1) knowledge-based optimization of N fertilizer rate strategy, which maintains soil N supply to meet the dynamic vegetable demand in time, space and quantity; (2) innovative products and technology, which regulates the soil N forms and promotes the vegetable root growth to reduce the Nr loss; (3) integrated knowledge and products strategy (IKPS). The knowledge-based optimization of N fertilizer rate strategy and innovative products and technology, can maintain or increase vegetable yield, significantly improve NUE, and mitigate the region-specific and crop-specific Nr losses. More importantly, IKPS, based on combination of in-season root-zone N management strategy, innovative products and technology, and best crop cultivation management, is needed to produce more vegetables with lower Nr losses. [ABSTRACT FROM AUTHOR]

The understanding of relationships between the plants and environmental variables is important for ecological restoration. The objective of this research was to investigate the controlling soil factor in plant growth and salt tolerance of leguminous plant Alhagi sparsifolia Shap. (A. sparsifolia) in a saline desert ecosystem of western China. Results showed that coverage of A. sparsifolia was positively linked to soil total K. A. sparsifolia accumulated the toxic Na+ in either roots or stems and thus reduced their allocation in the leaves to adapt the salt stress. The most important factor that determined Na+ uptake of A. sparsifolia was soil total K content, which suggests that total K can alleviate toxic Na+ accumulation in A. sparsifolia. In addition, there was a significant negative correlation among toxic Cl- concentration in A. sparsifolia, soil total K and pH. Overall, soil total K accounted for 18.2% of plant growth and salt tolerance of A. sparsifolia, followed by soil pH 13.1%, and soil total P 11.6%. In order to restore A. sparsifolia in the degraded desert ecosystems on salinized soil, first we need to consider the effects of soil total K, and then synergistically consider the soil pH and total P. [ABSTRACT FROM AUTHOR]

Fall application of anhydrous ammonia in Manitoba is common but its impact on nitrous oxide (N2O) emissions is not well known. A 2-yr study compared application before freeze-up in late fall to spring pre-plant application of anhydrous ammonia on nitrous oxide (N2O) emissions from a clay soil in the Red River Valley, Manitoba. Spring wheat (Triticum aestivum L.) and corn (Zea mays L.) were grown on two 4-ha fields in 2011 and 2012, respectively. Field-scale flux of N2O was measured using a fluxgradient micrometeorological approach. Late fall treatment did not induce N2O emissions soon after application or in winter likely because soil was frozen. Application time did alter the temporal pattern of emissions with late fall and spring pre-plant applications significantly increasing median daily N2O flux at spring thaw and early crop growing season, respectively. The majority of emissions occurred in early growing season resulting in cumulative emissions for the crop year being numerically 33% less for late fall than spring pre-plant application. Poor yield in the first year with late fall treatment occurred because of weed and volunteer growth with delayed planting. Results show late fall application of anhydrous ammonia before freeze-up increased N2O emissions at thaw and decreased emissions for the early growing season compared to spring pre-plant application. However, improved nitrogen availability of late fall application to crops the following year is required when planting is delayed because of excessive moisture in spring. [ABSTRACT FROM AUTHOR]

The effects of band placement of enhanced efficiency fertilizers (EEF) on nitrous oxide (N2O) emissions are uncertain. Placement and EEF on N2O emissions from spring wheat (Triticum aestivum L.) at two locations in Manitoba, in 2011 and 2012 were examined. Treatments were a no N control and 80 kg N ha-1 at planting of five combinations of placement and granular N source: broadcast-incorporated urea (Ureaj) and, subsurface side-banded urea (Urea M; each row side-banded), midrow-banded urea (UreaM; placement between every other set of rows), midrow-banded environmentally smart nitrogen (ESN, Agrium, Inc.) (ESNM), and midrow-banded SuperU (Koch Industries Inc.) (SuperUM). Planting in 2011 was delayed 40 d compared to 2012. Planting coincided with higher soil temperature and moisture resulting in three- to sevenfold more growing season N2O emissions (ΣN2O) in 2011 than 2012. In 2011, SuperUM and ESNM reduced ΣN2O, emission factor (EF) scaled by N-applied EF, and yield-scaled N2O emission intensity (El) by 47, 67, and 55%, respectively, compared with Ureaj. In 2011, increasing placement concentration of N in order broadcast-incorporation, side-banding, and midrow-banding tended to decrease ΣN2O, EF, and El of granular urea, but not statistically significant. The ΣN2O and nitrate exposure (NE), were significantly correlated over the site-years, indicating N availability from treatments in part determined emissions. Grain yield and crop N uptake were unaffected by sources and placement. These results suggest for early season wet and warm conditions, EEF N sources can reduce emissions compared with granular urea. Further studies are required to clarify placement effects on N2O emissions. [ABSTRACT FROM AUTHOR]

A field study was conducted to examine the influence of landscape position on greenhouse gases (GHG) accumulation in the soil profile and surface emissions from an undulating cropped field in the Prairie Pothole Region (PPR) of Manitoba. The field was segmented into four landscape elements: cropped Upper, Middle, and Lower, and uncropped Riparian. In fall 2005 and from spring-thaw through a growing season of flax (Linum usitatissimum L.) in 2006, soil concentrations of N2O, CH4, CO2, and O2 at 5-, 15-, 35-, and 65-cm depths and surface emissions were measured. Gas contents in gaseous and aqueous form were estimated at soil depths of 0 to 65 cm. Spring-thaw increased concentrations and contents of N2O at 1 5 to 35 cm in the Lower and Riparian elements, though surface emissions occurred only in the former. This suggested N2O accumulated during spring-thaw in both elements but was consumed under prolonged anaerobic conditions of the Riparian element before reaching the soil surface. For the Lower element, addition of N fertilizer to the soil surface resulted in shallow (5 cm) accumulation of N2O but higher surface emissions than at spring-thaw. The Riparian element consistently had the highest CH4 emissions. These occurred after the spring- thaw N2O emissions and with the accumulation of CH4 in the soil profile and declining O2 concentration. Soil concentrations and profile contents of CO2, as well as surface emissions, were consistently higher in the Riparian than the cropped elements and showed a similar increase with progression of the growing season. Thus, unlike N2O and CH4, CO2 was not subject to consumption processes in soil. The results suggest limiting N2O emissions in depression areas may be possible by shifting N2O production from the near soil surface to lower depths. Promotion of aeration to encourage CH4 consumption in the soil surface may lower CH4 emissions in wet years. Generally, the accumulation depth of GHG varied across the landscape elements reflecting differences in the biophysical factors controlling production and consumption and, thus, determining the surface emissions. [ABSTRACT FROM AUTHOR]

Soil N2O emissions vary with N source. A study was undertaken on a clay soil in the Red River Valley, Manitoba, Canada, to deter- mine the effect of granular N fertilizers and dairy manure on N2O emissions from a field cropped to rapeseed (Brassica napus L.) in 2009 and spring wheat (Triticum aestivum L.) in 2010. Treatments included an unamended control, granular urea, controlled- release urea (ESN), stabilized urea (SuperU), and solid dairy manure added at rates to achieve a total of 140 kg available N ha-1 (product plus soil N test). The N fertilizers were broadcast and shallowly incorporated each spring before planting; the manure was broadcast incorporated the previous fall. Nitrous oxide emissions were monitored from planting to freeze in fall and during spring thaw in 2011 using static-vented chambers. In both years, N2O emissions occurred within 4 to 5 wk of planting but not in fall after manure application. Area-scale cumulative N2O emissions (∑N2O, kg N ha-1) from planting to freeze were control < ESN = manure < urea = SuperU. Nitrous oxide emission factors were 0.017 kg N2O -N kg-1 available N added for urea and SuperU and 0.007 kg N2O-N kg-1 available N for ESN. Seventy-eight percent of the variation in ∑N2O could be explained by NO3-intensity, an integration of soil NO3-concentrations during the study periods. Greater ∑N2O were also associated with higher yields. These findings suggest that N release rates, as indicated by NO3-intensity and yield, determined emissions. The results highlight the challenge of meeting crop demand yet reducing N2O emissions by selection of an N source. [ABSTRACT FROM AUTHOR]

In the paper, a basic block based instruction prefetching (BBIP) mechanism is proposed that takes advantage of the relative small program size of the real-time application and the all or none attribute of basic blocks during execution. BBIP can not only avoid the useless prefetchings that exist in existing prefetching mechanisms, but also simplify the worst-case execution time (WCET) analysis of real-time applications. Results of simulation on 17 typical real-time benchmarks show that, about 70% to 80% misses can be removed, which leads to a remarkable decrease in execution time, about 50% for most benchmarks, even as high as 58%, compared with that collected on caches without instruction prefetching. [ABSTRACT FROM AUTHOR]

Abstract: To meet the growing demand for entertainment, the software running on Digital TV(DTV) becomes more and more powerful and complex. How to efficiently and accurately verify the applications puts a great challenge upon manufactures and application vendors. In this paper, we propose a fully automated system supporting black box test for software on DTV. The objectives and design of the testing system are thoroughly discussed. Finally, the usability and effectiveness of the proposed methodology has been experimentally evaluated. Detailed analysis of the experiment results has been reported, which shows that our system can improve the testing efficiency and have a high performance with verification accuracy. [Copyright &y& Elsevier]

growth chamber study was conducted to evaluate the effect of application of phosphate fertilizer on soil solution dynamics of cadmium (Cd) and Cd accumulation in durum wheat ( Triticum turgidum L. var. durum). Treatments consisted of three phosphate fertilizer sources containing 3.4, 75.2, and 232 mg Cd kg applied at three rates (20, 40 and 80 mg P kg) plus a no fertilization control. An unplanted treatment at 40 mg P kg was included to separate the effects on soil solution Cd dynamics of the crop from that of the fertilizer. Soil solution samples were obtained using soil moisture samplers every 10 days after germination. The experimental results indicated that plant biomass significantly increased with P application rates and decreased with increased Cd concentration in the phosphate fertilizers. Total cadmium concentration in soil solution was not consistently affected by phosphate fertilization rate and fertilizer sources, and therefore Cd concentration in the fertilizer. Application of phosphate fertilizer, however, increased the concentration and accumulation of Cd and shoot Cd/Zn ratio, and decreased shoot Zn concentration in durum wheat. Phosphate sources had a marginally significant effect ( P = 0.05) on shoot Cd concentration and did not affect Cd accumulation in durum wheat. Concentration of Cd in soil solution was unrelated to Cd concentration in durum wheat. These results suggest that the immediate increase in Cd concentration and Cd accumulation in durum wheat with phosphate application is due more to competition between Zn and Cd for absorption into plants, enhanced root to shoot translocation and enhanced root development, than to a direct addition effect from Cd contained in phosphate fertilizer. In the short term, application of phosphate fertilizers can increase Cd concentration in the crops, regardless of the Cd concentration of the fertilizer. An optimal P fertilization, possibly in combination with Zn application, may offer an important strategy for decreasing Cd concentration and accumulation in crops. [ABSTRACT FROM AUTHOR]

Cadmium concentration in durum ( Triticum durum L.) grain may be influenced by fertilizer management. A three year field study was conducted at two locations in southwestern Manitoba, Canada, to determine the effect of source, timing and placement of N fertilizer on grain Cd concentration of durum wheat under reduced-tillage (RT) and conventional-tillage (CT) management. There was a significant year-to-year variation in grain yield and grain Cd concentration, indicating a strong effect of environment on phytoavailability of Cd. Soil type also had a dominating effect on Cd in durum grain. Grain Cd concentration and accumulation were always lower at the Newdale clay loam (CL) location than the Stockton fine sandy loam (FSL) location. Compared to CT, RT management decreased grain Cd concentration and accumulation. Application of N fertilizer significantly increased grain Cd concentration and decreased grain Zn concentration. The increase in grain Cd could be due to the increasing Cd concentration in soil solution, the improved crop growth, or a competitive interaction between Cd and Zn for binding sites in the soil system and for uptake sites in the roots, following the application of N fertilizer. Time, source and placement of N fertilization showed inconsistent effect on grain yield and grain Cd concentration. The effects when observed were minor compared to effects of year and soil type on grain Cd concentration. Application of anhydrous ammonia (NH) generally resulted in higher Cd concentration in durum grain than application of same level of other N sources including urea ammonium nitrate (UAN), urea and ammonium nitrate (AN), probably due to greater N efficiency from the NH as compared to the other sources. Where differences due to placement occurred, banded application of fertilizers generally resulted in higher Cd concentration in durum grain than did dual-banded placement, indicating a higher fertilizer availability. Soil type, year and N fertilization greatly affected concentration of Cd in durum grain. Selection of a suitable source, timing and placement combination of N fertilization is important in optimizing crop yield and minimizing grain Cd concentration. [ABSTRACT FROM AUTHOR]