Multi Location Field Evaluation of BC1F2 Sorghum Populations for Striga Resistance in Niger

In Niger, a landlocked country, sorghum is the second staple food cultivated over the country by smallholder farmer. The crop is important for human and animal consumption. Despite its importance, the crop is affected by biotic and abiotic constraints. Among those constraints, striga has a high impact on yield. In fact, to survive, farmers are growing their local preferred sorghum varieties wish is highly sensible to the weed. Striga management is a challenge that requires a permanent solution. In addition, the development of high-yielding Striga resistant genotypes will be appreciated by farmers. The development of striga resistance will be based on the breeding population performances under farmer’s diverse environmental conditions adaptation. The main objective of this study is to evaluate two breeding populations for striga resistance in two different environments at Boulke and Dibissou in Tahoua region, to identify the early and high-yielding striga tolerant genotypes under natural infestation.

The impact of heavy metals on bacterial tolerance of antibiotic resistance and growth in the aquatic environment of Vietnam

Heavy metals may induce bacterial antibiotic resistance and affect their growth in the ecosystem.In this study,we aim to determine bacterial growth and antibiotic resistance in the pressure of heavy metals.Observed the changing morphology by gram staining was checked for bacterial toleration with heavy metal,developing of the colony form unit(CFU)was analysed bacterial kinetic growths and their biofilm formation.The disk diffusion test was used to perform bacterial susceptibility profiles with Ceftazidime(30μg),Ceftriaxone(30μg),Colistin sulfate(10μg),Meropenem or Imipenem(10μg),Ciprofloxacin(5μg)and Azithromycin(15μg)and the CLSI was applied for interpreting the data.The bacterial morphology remarkably changed from normal to short,round shape at a high concentration of heavy metals after 1 month.Their changing shape adapted to heavy metals by survival growing and resisted to Azithromycin,Ciprofloxacin,and Colistin without biofilm formation after 1 month,that was continued increasing after 2 months.The bacterial growth and antibiotic resistance were significant differences between provinces(P=0.01),type of bacterial species,and concentration of heavy metals.These results indicate that heavy metals are a crucial factor-driven for enhancing bacterial adaptation in pollution water resources and inducing their antimicrobial resistance in the aquatic environment.

Comparing Resistant Microorganisms Isolated from Patients and Environment in an Intensive Care Unit

Background: Recently, the probable involvement of surfaces from the hospital environment as a disseminating source of resistant bacteria has been highlighted. The aim of the study was to compare resistant microorganisms isolated from inanimate surfaces, equipments and patient blood culture samples in an Intensive Care Unit from Belo Horizonte, Brazil. Methods: A cross-sectional study was performed from July to October 2009. Data sources were microbiologic samples from environment and patient blood culture. Duplicate samples were obtained by swabs from up to seven different touch sites around two different patients in four different days. Jointly with the environmental samples, bacterial isolates from an adult ICU patients’ routine blood cultures were obtained from hospital laboratory. The samples were identified, tested for sensitivity and compared by rep-PCR test to verify similarity. Results: Difference among the averages of Colony Forming Units was found within the environment samples (p < 0.004). In the environment were identified antibiotic resistant microorganisms such as Vancomycin resistant Enterococcus faecalis, imipenem and ciprofloxacin Pseudomonas aeruginosa and multidrug-resistant Acinetobacter baumannii. Similarities (60% -80%) were established among environmental and blood culture samples. Conclusion: The environmental sampling showed different averages of contamination of the surfaces and equipment. The similarity among the bacterial isolates of patients’ blood cultures and environmental samples reinforces the hypothesis of the horizontal transference of pathogens.

Corrosion Resistance Enhancement of Pure Zirconium in Various Environments via Microstructure Tailoring

The corrosion properties of pure zirconium(Zr)with different grain sizes in acid,alkali,and salt environments were studied.The microstructures of pure Zr were observed by optical microscope,X-ray diffractometer,and electron backscattered diffraction probe.The corrosion resistance of pure Zr was analyzed by electrochemical corrosion test and immersion test.Results show that pure Zr with grain size of 4–32μm can be obtained after annealing at 800°C for different durations,and the relationship between grain size and annealing duration is D^(3)−D_(0)^(3)=3.35t.The electrochemical corrosion and immersion corrosion test results show that the pure Zr with grain size of about 24μm(annealing at 800°C for 20 h)possesses the optimal corrosion resistance.

The Frost-resisting Durability of High Strength Self-Compacting Pervious Concrete in Deicing Salt Environment

A high strength self-compacting pervious concrete(SCPC) with top-bottom interconnected pores was prepared in this paper. The frost-resisting durability of such SCPC in different deicing salt concentrations(0%, 3%, 5%, 10%, and 20%) was investigated. The mass-loss rate, relative dynamic modulus of elasticity, compressive strength, flexural strength and hydraulic conductivity of SCPC after 300 freeze-thaw cycles were measured to evaluate the frost-resisting durability. In addition, the microstructures of SCPC near the top-bottom interconnected pores after 300 freeze-thaw cycles were observed by SEM. The results show that the high strength SCPC possesses much better frost-resisting durability than traditional pervious concrete(TPC) after 300 freeze-thaw cycles, which can be used in heavy loading roads. The most serious freeze-thaw damage emerges in the SCPC immersed in the 3% of Na Cl solution, while there is no obvious damage in 20% of Na Cl solution. Furthermore, it can be deduced that the high strength SCPC can be used for 100 years in a cold environment.

Landscape of global urban environmental resistome and its association with local socioeconomic and medical status

Antimicrobial resistance(AMR)poses a critical threat to global health and development,with environmental factors—particularly in urban areas—contributing significantly to the spread of antibiotic resistance genes(ARGs).However,most research to date has been conducted at a local level,leaving significant gaps in our understanding of the global status of antibiotic resistance in urban environments.To address this issue,we thoroughly analyzed a total of 86,213 ARGs detected within 4,728 metagenome samples,which were collected by the Meta SUB International Consortium involving diverse urban environments in 60 cities of 27 countries,utilizing a deep-learning based methodology.Our findings demonstrated the strong geographical specificity of urban environmental resistome,and their correlation with various local socioeconomic and medical conditions.We also identified distinctive evolutionary patterns of ARG-related biosynthetic gene clusters(BGCs)across different countries,and discovered that the urban environment represents a rich source of novel antibiotics.Our study provides a comprehensive overview of the global urban environmental resistome,and fills a significant gap in our knowledge of large-scale urban antibiotic resistome analysis.

Heat strain in chemical protective clothing in hot-humid environment:Effects of clothing thermal properties

Heat strain experienced by individuals wearing chemical protective clothing(CPC)is severe and dangerous especially in hot-humid environment.The development of material science and interdisciplinary studies including ergonomics,physiology and heat transfer is urgently required for the reduction of heat strain.The aim of this paper was to study the relationship among clothing thermal properties,physiological responses and environmental conditions.Three kinds of CPC were selected.Eight participants wore CPC and walked(4 km/h,two slopes with 5%and 10%)on a treadmill in an environment with(35±0.5)℃ and RH of(60±5)%.Core temperature,mean skin temperature,heart rate,heat storage and tolerance time were recorded and analyzed.Physiological responses were significantly affected by the clothing thermal properties and activity intensity in hot-humid environment.The obtained results can help further development of heat strain model.New materials with lower evaporative resistance and less weight are necessary to release the heat strain in hot-humid environments.

Drug resistance and new therapies in colorectal cancer

Colorectal cancer(CRC) is often diagnosed at an advanced stage when tumor cell dissemination has taken place. Chemo-and targeted therapies provide only a limited increase of overall survival for these patients. The major reason for clinical outcome finds its origin in therapy resistance. Escape mechanisms to both chemo-and targeted therapy remain the main culprits. Here, we evaluate major resistant mechanisms and elaborate on potential new therapies. Amongst promising therapies is α-amanitin antibodydrug conjugate targeting hemizygous p53 loss. It becomes clear that a dynamic interaction with the tumor microenvironment exists and that this dictates therapeutic outcome. In addition, CRC displays a limited response to checkpoint inhibitors, as only a minority of patients with microsatellite instable high tumors is susceptible. In this review, we highlight new developments with clinical potentials to augment responses to checkpoint inhibitors.

ALLOY ELEMENTS' EFFECT ON STEEL CORROSION IN MARINE ENVIRONMENT

Investigation of the effect of alloy elements on the corrosion resistance of 18 types of low alloy steel in marine atmospheric zone, splash zone and seawater zone by the electric connection method showed that the corrosion resistance of low alloy steel was obviously affected by Cu, P, Mo in the marine atmospheric zone, by P, Mo, Cu in the splash zone, and by Al, Cr in the seawater zone. The experimental results were used to derive three regression equations to describe the corrosive behavior of these steels.

Research on shock resistance of modularization cabin

Underwater explosion impulsive loading would not only cause serious damage to ship structure,but also influence the shock resistance of cabin structure.In this paper,based on Duha Man integral theory,the idea of cabin structure about isolation vibration based on modularization design was presented,which can improve the shock resistance of existing cabins.The shock resistance analysis of the modularization cabin about connection pattern by bolt,single-layer,double-layer and floating raft system of vibration isolation is carried out.The results showed that the shock resistance of bolt is the worst and floating raft is relatively superior above all.

Roadmap to tackle antibiotic resistance in the environment under the One Health framework

Antibiotic resistance has been recognized as a major challenge worldwide for humans.“One Health”has been recognized as a key concept for containment of antibiotic resistance.Under the framework,the role of the environment in the development of antibiotic resistance genes(ARGs)has become increasingly obvious.Despite numerous efforts,response to antibiotic re-sistance is considered to be inadequate,which is probably due to the lack of a clear roadmap.Here,we propose a“One Health”roadmap to combat antibiotic resistance in the environment through(1)understanding environmental resistome.The environmental gene pool has long been recognized as the single largest reservoir of both known and novel ARGs.(2)Standardizing ARG quantification.Systematic joint efforts based on standardized quantification are urgently needed to un-derstand the true tempospatial profiles of the environmental resistome.(3)Identifying mechanisms of resistome development.Horizontal gene transfer and co-selection have been recognized as the two main mechanisms contributing to the environmental resistome.(4)Establishing a risk-assessment framework.The first critical step for large-scale cost-effective targeted ARG management in the environment is the risk assessment to identify the priority ARGs for control.(5)Formulating regulatory standards.By correlating the environmental ARG profile with public health,we may identify the indicator ARGs that can be integrated into current environmental quality standards.(6)Developing control strategies.Systematic analysis of available control technologies is required to identify the most feasible ones to curtail the spread of ARGs in the environment.The proposed roadmap under the“One Health”framework provides a guide to tackle antibiotic resistance in the environment.

Effects of mechanical boundary conditions on thermal shock resistance of ultra-high temperature ceramics

The effects of mechanical boundary conditions, often encountered in thermalstructural engineering, on the thermal shock resistance（TSR） of ultra-high temperature ceramics（UHTCs） are studied by investigating the TSR of a UHTC plate with various types of constraints under the first, second, and third type of thermal boundary conditions. The TSR of UHTCs is strongly dependent on the heat transfer modes and severity of the thermal environments. Constraining the displacement of the lower surface in the thickness direction can significantly decrease the TSR of the UHTC plate, which is subject to the thermal shock at the upper surface. In contrast, the TSR of the UHTC plate with simply supported edges or clamped edges around the lower surface is much better.

Adaptability and Phenotypic Stability of Resistance to Two Viral Diseases and Yield Traits in Cassava

Cassava productivity is hampered by pests and diseases including cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). The main objective of this study was to identify stable superior genotypes that combine disease resistance and high yield. Sixteen cassava genotypes were planted in a randomized complete block design with three replications for six planting seasons (years) at five sites in Tanzania. The genotypes were assessed using the additive main effect and multiplicative interaction (AMMI) analysis, and highly significant (P < 0.001) effects of genotype, environment, and genotype-by-environment (G*E) interactions were observed for all traits studied. Percent sum of squares (SS) due to environment (12.66% - 85.23%) was the highest followed by G*E (14.12% - 39.56%) for CMD foliar symptoms, root weight and dry matter. On the other hand, % SS due to genotype (52.14% - 69.14%) was highest followed by G*E (26.14% - 35.91%) for CBSD foliar and root symptoms indicating that the environment and G*E greatly influenced trait expression. The most stable genotypes which combined disease resistance and high yield were NDL 2003/31 and NDL 2003/111. The findings of this study will give impetus for the release of new cassava varieties that are not only high yielding but are also dually resistant to both CMD and CBSD in different locations and sites.

Energy Consumption and Erosion Mechanism of Polyester Fiber Reinforced Cement Composite in Wind-blown Sand Environments

Considering the economic and environmental benefits associated with the recycling of polyester(PET)fibres,it is vital to study the application of fibre-reinforced cement composites.According to the characteristics of the wind-blown sand environment in Inner Mongolia,the erosion resistance of the polyester fibre-reinforced cement composites(PETFRCC)with different PET fibre contents to various erosion angles,velocities and sand particle flows was investigated by the gas-blast method.Based on the actual conditions of sandstorms in Inner Mongolia,the sand erosion parameters required for testing were calculated by the similarity theory.The elastic-plastic model and rigid plastic model of PETFRCC and cement mortar were established,and the energy consumption mechanism of the model under particle impact was analyzed.The experimental results indicate that the microstructure of PETFRCC rafter hydration causes a spring-like buffering effect,and the deformation of PETFRCC under the same impact load is slightly smaller than that of cement mortar,and the damage mechanism of PETFRCC is mainly characterized by fiber deformation and slight brittle spalling of matrix.And under the most unfavorable conditions of the erosion,the erosion rate of 0.5PETFRCC is about 57.69%lower than that of cement mortar,showing better erosion resistance.

Highly reliable and selective ethanol sensor based on α-Fe2O3 nanorhombs working in realistic environments

A highly reliable and selective ethanol gas sensor working in realistic environments based on alpha-Fe2O3(α-Fe2O3)nanorhombs is developed. The sensor is fabricated by integrating α-Fe2O3 nanorhombs onto a low power microheater based on micro-electro-mechanical systems(MEMS) technology. The α-Fe2O3 nanorhombs, prepared via a solvothermal method, is characterized by transmission electron microscopy(TEM), Raman spectroscopy, x-ray diffraction(XRD), and x-ray photoelectron spectroscopy(XPS). The sensing performances of the α-Fe2O3 sensor to various toxic gases are investigated. The optimum sensing temperature is found to be about 280℃. The sensor shows excellent selectivity to ethanol.For various ethanol concentrations(1 ppm-20 ppm), the response and recovery times are around 3 s and 15 s at the working temperature of 280℃, respectively. Specifically, the α-Fe2O3 sensor exhibits a response shift less than 6% to ethanol at280℃ when the relative humidity(RH) increases from 30% to 70%. The good tolerance to humidity variation makes the sensor suitable for reliable applications in Internet of Things(IoT) in realistic environments. In addition, the sensor shows great long-term repeatability and stability towards ethanol. A possible gas sensing mechanism is proposed.

Evaluation of Factors of Soil Resistivity in the Niger Delta

Soil conductivity is responsible for its aggressive behavior to metallic objects either in contact or buried in the ground. Rapid deterioration and eventual rupture of pipelines leading ultimately to crude oil spillages have been of economic as well as environmental concern. Although many factors contribute to soil resistivity, these relationships have hardly been quantitatively expressed. This paper explores the factors affecting soil resistivity firstly by matching the spatial regional distribution with each of the identified factors of influence, including ground elevation soil type, depth to water table and undrained strength. 183 Vertical Electrical Sounding VES with the ABEM SAS 1000, using Schlumberger electrode configuration were carried out along a pipeline route to generate resistivity distribution across a linear alignment that traverses three geomorphic sub-environments in the Niger Delta Region. The apparent resistivity values averaged over depths of 3 m and 10 m were plotted against the co-ordinates using Surfer-16 and overlaid on Google earth Pro to produce a spatial distribution with enhanced location visibility. The results show that apparent resistivity is influenced by depth to water table with lower values in areas of shallow water table occurrence. Furthermore, it is shown that changes in resistivity below the water table are more due to variation in soil type. Within a soil type above the water table, soil resistivity increases monotonically with depth until the depth of probe extends to a different soil horizon. Results of this study provide guidance as to what ground resistivity to expect in different part of the delta as well as provide valuable information to assess the risks to assets either as a means of prioritizing maintenance or of improving design for new installations in the Niger Delta Region.

钴含量对Ni-W-Co合金镀层耐蚀性的影响

[目的]研究镀层Co含量对Ni-W-Co合金镀层耐蚀性的影响。[方法]通过调节镀液的钴盐(Co SO_(4)·7H_(2)O)用量,在N80钢表面直流电沉积得到不同Co含量的Ni-W-Co合金。通过镀层厚度测量、成分分析、形貌观察、全浸腐蚀试验、动电位极化曲线测试等方式研究了钴盐质量浓度对沉积速率及合金镀层成分、形貌和耐蚀性的影响。[结果]随着镀液中钴盐质量浓度的增大,沉积速率增大,镀层的Co质量分数增大,表面变得粗糙,耐蚀性先变好后变差。Co SO_(4)·7H_(2)O的质量浓度为2.0 g/L时获得的Ni-W-Co合金镀层在5%Na Cl溶液和土酸溶液(由10%盐酸与5%氢氟酸组成)中的腐蚀速率最低,耐蚀性最佳。[结论]通过调整镀液的钴盐用量可电沉积得到适用于油田环境的耐腐蚀Ni-W-Co合金镀层。

电阻探针腐蚀监测技术的研究进展

介绍了电阻探针腐蚀监测系统和监测原理,综述了当前国内外电阻探针腐蚀监测技术的研究进展,重点分析了有关电阻探针腐蚀监测系统在电阻探针、监测数据处理和监测数据传输方向的研究现状,总结了电阻探针腐蚀监测技术在大气环境、水环境和土壤环境3种不同环境下应用的研究进展,最后对电阻探针腐蚀监测技术进行了展望,以为电阻探针腐蚀监测技术的发展和应用提供新的思路和指导意义。

无引线封装的SOI高温压力传感器设计

为解决高温环境下的压力监测问题,对无引线封装压力传感器进行了研究。首先,对高温压力敏感芯片进行设计,使用绝缘体上硅(SOI)材料提高了敏感芯片的高温稳定性;使用Ti⁃Pt⁃Au复合电极提高了金属电极与硅引线之间欧姆接触的可靠性。使用导电银浆实现敏感芯片电极和基座引脚的电连接,使用玻璃浆料实现芯片与基座的耐高温封装。利用同步热分析仪对导电银浆和玻璃浆料进行了DSC⁃TG同步分析,并借助扫描电镜对其微观形貌进行对比观察,确定其最佳烧结工艺曲线。对封装后的压力传感器进行测试,结果表明:传感器在25~300℃范围内具备优异的性能,综合精度可达0.25%FS。

时局、地理与全面抗战时期的云南蚕桑业

抗战时期是云南蚕桑业发展的重要阶段。为推动后方建设,支援抗战,促进地方经济发展,云南蚕桑业发展受到国民政府、云南地方和社会各界的重视,提出了云南蚕桑复兴计划,在宜蚕区积极推广蚕桑业。但是,受云南特殊的高原山地地理环境的制约,以及“战时”影响,在较短时间内,云南蚕桑业发展的成效较为有限。