With the goal of evaluating the wave and wave energy conditions in the Philippines,the simulated wave nearshore(SWAN)model was used to estimate the wavefield using 30 years of cross-calibrated multi-platform(CCMP)wind...With the goal of evaluating the wave and wave energy conditions in the Philippines,the simulated wave nearshore(SWAN)model was used to estimate the wavefield using 30 years of cross-calibrated multi-platform(CCMP)wind field data(1987-2016).The spatiotemporal patterns of annual and monthly averaged significant wave heights and wave energy in the Philippines were analyzed based on the simulated data.Results showed that they had similar values;in particular,significant wave heights and wave energy were smaller in the south and southwest and higher in the north and northeast.A total of 12 representative points along the Philippine coast were selected to draw wave and wave energy roses.A directional analysis showed that the dominant wave was in the north north-east(NNE),northeast(NE),and east north-east(ENE)directions.Wave energy was mainly distributed in regions with an energy period between 1 and 10 s and significant wave heights between 0 and 4 m.To better utilize wave energy data in the Philippines,this paper studied the available and rich area of wave energy and analyzed the annual and monthly variability index of wave energy in the country.Moreover,the available significant wave heights of wave energy conversion devices(WECs)were set as 0.5-4 m,and the maximum annual average available wave energy occurred in the eastern Philippine Sea area,reaching 13 kW m^(-1).For the safety of WECs,extreme typhoon-induced wave conditions must be considered.Furthermore,the results showed that the maximum significant wave height and mean period over the 50-year return period reached 18 m and 15 s,respectively.展开更多
Background: Malaria remains a major cause of morbidity and mortality in Zambia, affecting all levels of society, with children under the age of five and pregnant women being most at risk of serious illness. The availa...Background: Malaria remains a major cause of morbidity and mortality in Zambia, affecting all levels of society, with children under the age of five and pregnant women being most at risk of serious illness. The availability of antimalarial medicines is one of the key interventions of malaria management. This study assessed the availability of antimalarial medicines in community pharmacies in Lusaka district, Zambia. Materials and Methods: This was a cross-sectional study that was conducted among 210 community pharmacies from September to November 2022 using a well-structured checklist in selected areas of Lusaka district. The availability was verified by a physical check of the product. The checklist contained the medicines listed both in the guidelines for diagnosis and treatment of malaria in Zambia as well as in the World Health Organization (WHO) malaria treatment guidelines. Results: This study found that all antimalarials listed in the local treatment guidelines for malaria were available in community pharmacies, though with the varying distribution. Of the 210 community pharmacies, 209 (99.5%) had artemether/lumefantrine in stock. The lowest available antimalarial was quinine/clindamycin, which was only available in 3 (1.4%) of the outlets. Conversely, 3 out of 16 (18.8%) antimalarials that were available in community pharmacies were not listed in the local treatment guidelines of malaria in Zambia, despite being listed in the WHO malaria treatment guidelines. This translated into a compliance level of 81.2% based on the local malaria treatment guidelines. Conclusion: This study concluded that antimalarials were available for all categories of malaria management in community pharmacies, though with a varying distribution. The presence of antimalarials not listed in the Zambian treatment guidelines is of public health concern which may have an impact on antimicrobial resistance in the future.展开更多
Nitrogen(N) and phosphorus(P) are two essential mineral nutrients for plant growth,which are required in relative high amount in plants.Plants have evolved a series of strategies for coordinately acquiring and utilizi...Nitrogen(N) and phosphorus(P) are two essential mineral nutrients for plant growth,which are required in relative high amount in plants.Plants have evolved a series of strategies for coordinately acquiring and utilizing N and P.However,physiological and molecular mechanisms underlying of N and P interactions remain largely unclear in soybean(Glycine max).In this study,interactions of N and P were demonstrated in soybean as reflected by significant increases of phosphate(Pi) concentration in both leaves and roots by N deficiency under Pi sufficient conditions.A total of four nitrogen limitation adaptation(NLA),encoding RING-type E3 ubiquitin ligase were subsequently identified in soybean genome.Among them,transcription of Gm NLA1-1 and Gm NLA1-3 was decreased in soybean by N starvation under Pi sufficient conditions,not for Gm NLA1-2.Suppression of all three Gm NLA1 members was able to increase Pi concentration regardless of the P and N availability in the growth medium,but decrease fresh weight under normal conditions in soybean hairy roots.However,comparted to changes in control lines at two N levels,N deficiency only resulted in a relatively higher increase of Pi concentration in Gm NLA1-1 or Gm NLA1-3 suppression lines,strongly indicating that Gm NLA1-1 and Gm NLA1-3 might regulate P homeostasis in soybean response to N starvation.Taken together,our result suggest that redundant and diverse functions present in Gm NLA1 members for soybean coordinate responses to P and N availability,which mediate P homeostasis.展开更多
To achieve the high availability of health data in erasure-coded cloud storage systems,the data update performance in erasure coding should be continuously optimized.However,the data update performance is often bottle...To achieve the high availability of health data in erasure-coded cloud storage systems,the data update performance in erasure coding should be continuously optimized.However,the data update performance is often bottlenecked by the constrained cross-rack bandwidth.Various techniques have been proposed in the literature to improve network bandwidth efficiency,including delta transmission,relay,and batch update.These techniques were largely proposed individually previously,and in this work,we seek to use them jointly.To mitigate the cross-rack update traffic,we propose DXR-DU which builds on four valuable techniques:(i)delta transmission,(ii)XOR-based data update,(iii)relay,and(iv)batch update.Meanwhile,we offer two selective update approaches:1)data-deltabased update,and 2)parity-delta-based update.The proposed DXR-DU is evaluated via trace-driven local testbed experiments.Comprehensive experiments show that DXR-DU can significantly improve data update throughput while mitigating the cross-rack update traffic.展开更多
This research article is based on a study of optimal frequency to the repairable system due to the failure finding interval to maximize as well as minimize the availability of some components devices. We studied toget...This research article is based on a study of optimal frequency to the repairable system due to the failure finding interval to maximize as well as minimize the availability of some components devices. We studied together maintenance and corrective actions that carried out item of failure and periodic failure finding designed to check whether a system is still working. The model is proved as well as useful application in detecting the problem related to finding failure tasks of different scheme devices by maximization. The model formulated and the numerical application to the relevant mathematical model have been discussed to demonstrate the article quality. Therefore based on probability analytic development, the optimal maintenance policy is then obtained as solution of an optimization problem in which the maintenance cost rate is the objective function and the risk of corrective maintenance is the constraint function. Finally, the solution to the optimal device in the considered development model has been well adjusted due to derivation to the experimental observation rather than theory which will be taken into consideration in the next applied practical design research related and the system device provided that, the proactive device agreed with using the exponential distribution to the survive distribution function which can not be considered as valid.展开更多
Unified identity authentication has become the basic information service provided by colleges and universities for teachers and students. Security, stability, high concurrency and easy maintenance are our requirements...Unified identity authentication has become the basic information service provided by colleges and universities for teachers and students. Security, stability, high concurrency and easy maintenance are our requirements for a unified identity authentication system. Based on the practical work experience of China University of Geosciences (Beijing), this paper proposes a high availability scheme of unified identity authentication system based on CAS, which is composed of multiple CAS Servers, Nginx for load balancing, and Redis as a cache database. The scheme has been practiced in China University of Geosciences (Beijing), and the application effect is good, which has practical reference significance for other universities.展开更多
All the regulations that define a maximum concentration of metals in the receiving soil are based on total soil metal concentration. However, the potential toxicity of a heavy metal in the soil depends on its speciati...All the regulations that define a maximum concentration of metals in the receiving soil are based on total soil metal concentration. However, the potential toxicity of a heavy metal in the soil depends on its speciation and availability. We studied the effects of heavy metal speciation and availability on soil microorganism activities along a Cu/Zn contamination gradient. Microbial biomass and enzyme activity of soil contaminated with both Cu and Zn were investigated. The results showed that microbial biomass was negatively affected by the elevated metal levels. The microbial biomass-C (Cmic)/organic C (Corg) ratio was closely correlated to heavy metal stress. There were negative correlations between soil microbial biomass, phosphatase activity and NH4NO3 extractable heavy metals. The soil microorganism activity could be predicted using empirical models with the availability of Cu and Zn. We observed that 72% of the variation in phosphatase activity could be explained by the NH4NO3-extractable and total heavy metal concentration. By considering different monitoring approaches and different viewpoints, this set of methods applied in this study seemed sensitive to site differences and contributed to a better understanding of the effects of heavy metals on the size and activity of microorganisms in soils. The data presented demonstrate the relationship between heavy metals availability and heavy metal toxicity to soil microorganism along a contamination gradient.展开更多
The availability of three dissolved organic phosphorus (DOP) compounds as nutrient sources for experimentalcultare of three algae was studied. Results indicated that these compounds could be utilized byalgae, and th...The availability of three dissolved organic phosphorus (DOP) compounds as nutrient sources for experimentalcultare of three algae was studied. Results indicated that these compounds could be utilized byalgae, and that dissolved inorganic phosphorus (DIP) was first to be uptaken when various forms ofphosphorus (DIP and DOP) co-existed. Dicrateria zhanjiangensis’ uptake of sodium glycerophosphatewas faster than that of D-ribose-5-phosphate. The increase of sodium glycerphosphate had little effecton the maximum uptake rate(V<sub>max</sub>) of Chlorella sp., but increased the semisaturation constant(K<sub>s</sub>) remarkably;the photosynthesis rates(PR) of Dicrateria zhanjiangensis and Chlorella sp. were rarely affected byusing various forms of phosphorus in the culture experiments. The possible DOP pathways utilizedby algae are discussed.展开更多
Eremosparton songoricum (Litv.) Vass is a dwarf clonal shrubby legume developed on the windward slopes of mobile or semi-fixed sand dunes of Central Asia. It is assumed that E. songoricum must possess a high degree ...Eremosparton songoricum (Litv.) Vass is a dwarf clonal shrubby legume developed on the windward slopes of mobile or semi-fixed sand dunes of Central Asia. It is assumed that E. songoricum must possess a high degree of phenotypic plasticity for such a heterogeneous habitat. The variations of E. songoricum plants growing in two typical microhabitats (the upper slope and the lower slope of semi-mobile dune) were investigated. The morphological characteristics and the biomass allocation patterns were measured and compared at the clonal fragment level. Compared with the clonal fragment on the lower slope of dune, the clonal fragment on the upper slope of the dune (a) declined in total biomass and ramet height, (b) increased the length of rhizomes and the number of roots, (c) increased the degree of asym- metry, and (d) heightened allocation to the belowground biomass. Our results confirmed the hypothesis of high phenotypic adjustment capacity of E. songoricum to habitat moisture availability. Phenotypic plasticity of E. songoricum contributed to reduce the damage risk, led to an environmentally induced specialization in function of resources exploitation, resulted in its persistence in heterogeneous environments and was adaptive in sand dune environment.展开更多
Soil with low phosphorus (P) availability and organic matter contents exists in large area of southwest of China, but some soybean genotypes still show well adaptations to this low yield farmland. However, to date, th...Soil with low phosphorus (P) availability and organic matter contents exists in large area of southwest of China, but some soybean genotypes still show well adaptations to this low yield farmland. However, to date, the underlying mechanisms of how soybean regulates soil P availability still remains unclear, like microbe-induced changes. The objective of the present study was to compare the differences of rhizosphere bacterial community composition between E311 and E109 in P-sufficiency (10.2 mg kg^-1) and P-insufficiency (5.5 mg kg^-1), respectively, which then feedback to soil P availability. In P-sufficiency, significant differences of the bacterial community composition were observed, with fast-growth bacterial phylum Proteobacteria, genus Dechloromonas, Pseudomonas, Massilia, and Propionibacterium that showed greater relative abundances in E311 compared to E109, while in P-insufficiency were not. A similar result was obtained that E311 and E109 were clustered together in P-insufficiency rather than in P-sufficiency by using principal component analysis and hierarchical clustering analysis. The quadratic relationships between bacterial diversity and soil P availability in rhizosphere were analyzed, confirming that bacterial diversity enhanced the soil P availability. Moreover, the high abundance of Pseudomonas and Massilia in the rhizosphere of E311 might increased the P availability. In the present study, the soybean E311 showed capability of shaping rhizosphere bacterial diversity, and subsequently, increasing soil P availability. This study provided a strategy for rhizosphere management through soybean genotype selection and breeding to increase P use efficiency, or upgrade middle or low yield farmland.展开更多
The new model for parallel repairable system is introduced, and it is based on the practice problems of maintenance and the idea of Ion-Channel modeling. In the new model, repair times that are sufficiently short (le...The new model for parallel repairable system is introduced, and it is based on the practice problems of maintenance and the idea of Ion-Channel modeling. In the new model, repair times that are sufficiently short (less than some critical value) do not result in system failure, and such a repair interval is omitted from the downtime record. Usually, the underlying process is Markov process if the durations of working and repair time have the negative-exponential distributions, but the new system has not the Markov properties, which is worth to study. The reliability indexes such as instantaneous availability and steady-state availabilities for the new system are given through probability analysis. A numerical example is given to illustrate the results.展开更多
One hundred and forty-four Avin broilers (1 d of age) were randomly divided into six groups, with three replicates of eight birds each to study on the effects of different oligosaccharides on performance and availabil...One hundred and forty-four Avin broilers (1 d of age) were randomly divided into six groups, with three replicates of eight birds each to study on the effects of different oligosaccharides on performance and availability of nutrients in broilers. The control group(Group I)was fed with corn-soybean meal as basal diet, and the trial groups (Group II, III, IV,V and VI) were fed with basal diet plus 0.1% Manoligosaccharides(MOS), 0.3% Soybean-Oligosaccharides(SBOS), 0.3% Fructo-oligosaccharides(FOS), 0.3% α-Glucooligosaccharides(α-GOS) and 50 mg·L-1 Chlortetracycline(CTC), respectively. The results showed that the supplementation of oligosaccharides slightly improved daily gain and feed intake. SBOS supplementation improved, but MOS and α-GOS significantly decreased availability of energy. Oligosaccharides supplementation improved availability of energy, phosphorus, calcium, magnesium and iron, and significantly increased cholesterol content of fecal, and did not affect on availability of protein and cholesterol contents in serum and muscle. Availability of phosphorus of broilers fed with FOS was much higher than that with α-GOS. SBOS supplementation remarkably increased availability of iron.展开更多
Conventional reliability models of belt drive systems in the failure mode of fatigue are mainly based on the static stress strength interference model and its extended models, which cannot consider dynamic factors in ...Conventional reliability models of belt drive systems in the failure mode of fatigue are mainly based on the static stress strength interference model and its extended models, which cannot consider dynamic factors in the operational duration and be used for further availability analysis. In this paper, time-dependent reliability models, failure rate models and availability models of belt drive systems are developed based on the system dynamic equations with the dynamic stress and the material property degradation taken into account. In the proposed models, dynamic failure dependence and imperfect maintenance are taken into consideration. Furthermore, the issue of time scale inconsistency between system failure rate and system availability is proposed and addressed in the proposed system availability models. Besides, Monte Carlo simulations are carried out to validate the established models. The results from the proposed models and those from the Monte Carlo simulations show a consistency. Furthermore, the case studies show that the failure dependence, imperfect maintenance and the time scale inconsistency have significant influences on system availability. The independence assumption about the belt drive systems results in underestimations of both reliability and availability. Moreover, the neglect of the time scale inconsistency causes the underestimate of the system availability. Meanwhile, these influences show obvious time-dependent characteristics.展开更多
This paper considers a project scheduling problem with the objective of minimizing resource availability costs appealed to finish al activities before the deadline. There are finish-start type precedence relations amo...This paper considers a project scheduling problem with the objective of minimizing resource availability costs appealed to finish al activities before the deadline. There are finish-start type precedence relations among the activities which require some kinds of renewable resources. We predigest the process of sol-ving the resource availability cost problem (RACP) by using start time of each activity to code the schedule. Then, a novel heuris-tic algorithm is proposed to make the process of looking for the best solution efficiently. And then pseudo particle swarm optimiza-tion (PPSO) combined with PSO and path relinking procedure is presented to solve the RACP. Final y, comparative computational experiments are designed and the computational results show that the proposed method is very effective to solve RACP.展开更多
Passive Optical Networks(PONs)are considered as the preferred solution for broadband fibre-based access networks.This is because PONs present low cost deployment,low energy consumption and also meet high bandwidth dem...Passive Optical Networks(PONs)are considered as the preferred solution for broadband fibre-based access networks.This is because PONs present low cost deployment,low energy consumption and also meet high bandwidth demands from end users.In addition,end users expect a high availability for access networks,while operators are more concerned about reducing the failure impact(number of clients affected by failures).Moreover,operators are also interested in reducing the cost of the access network.This paper provides a deep insight into the consequences that the physical topology and design decisions cause on the availability,the failure impact and the cost of a PON.In order to do that,the physical layout of the PON deployment area is approximated by a network geometric model.A PON deployed according to the geometric model is then assessed in terms of failure impact,availability and cost.This way,the effects of different design decisions and the physical layout on these three parameters are evaluated.In addition,the tradeoffs between availability,failure impact and cost caused by planning decisions and the physical topology are identified and pinpointed.展开更多
Fungi capable of arsenic(As) accumulation and volatilization are hoped to tackle As-contaminated environment in the future. However, little data is available regarding their performances in field soils. In this stud...Fungi capable of arsenic(As) accumulation and volatilization are hoped to tackle As-contaminated environment in the future. However, little data is available regarding their performances in field soils. In this study, the chlamydospores of Trichoderma asperellum SM-12F1 capable of As resistance, accumulation, and volatilization were inoculated into As-contaminated Chenzhou(CZ) and Shimen(SM) soils, and subsequently As volatilization and availability were assessed. The results indicated that T. asperellum SM-12F1 could reproduce well in As-contaminated soils. After cultivated for 42 days, the colony forming units(cfu) of T. asperellum SM-12F1 in CZ and SM soils reached 10^10–10^11 cfu g^–1 fresh soil when inoculated at a rate of 5.0%. Inoculation with chlamydospores of T. asperellum SM-12F1 could significantly accelerate As volatilization from soils. The contents of volatilized As from CZ and SM soils after being inoculated with chlamydospores at a rate of 5.0% for 42 days were 2.0 and 0.6 μg kg^–1, respectively, which were about 27.5 and 2.5 times higher than their corresponding controls of no inoculation(CZ, 0.1 μg kg^–1; SM, 0.3 μg kg^–1). Furthermore, the available As content in SM soils was decreased by 23.7%, and that in CZ soils increased by 3.3% compared with their corresponding controls. Further studies showed that soil p H values significantly decreased as a function of cultivation time or the inoculation level of chlamydospores. The p H values in CZ and SM soils after being inoculated with 5.0% of chlamydospores for 42 days were 6.04 and 6.02, respectively, which were lowered by 0.34 and 1.21 compared with their corresponding controls(CZ, 6.38; SM, 7.23). The changes in soil p H and As-binding fractions after inoculation might be responsible for the changes in As availability. These observations could shed light on the future remediation of As-contaminated soils using fungi.展开更多
The objectives of the current study were to estimate evapotranspiration(ET) over the grassland and assess seasonal variation of moisture availability at the wind-water erosion crisscross region in the northern Loess...The objectives of the current study were to estimate evapotranspiration(ET) over the grassland and assess seasonal variation of moisture availability at the wind-water erosion crisscross region in the northern Loess Plateau of China. The Liudaogou Catchment which has the representative climatic and hydrological characteristics of the wind-water erosion crisscross region was chosen as the study location. The reference crop evapotranspiration(ET 0) was estimated by Penmen method, which was recommended by FAO56 and the evapotranspiration over the grassland(ET) was estimated by Penmen-Monteith equation using the observed meteorological data with time unit of 1 h. The soil moisture availability factor was defined by m a =ET/ET 0. The calculated results for 2006 indicated that the total ET 0 was slightly more than the total yearly precipitation and ET accounted for 37 % of that, ET increased distinctly after the intensive rainfall event in the rainy season. Most of the m a was less than 0.4 and its annual mean was 0.34. It was expected that the results provided a basis for studies on dynamic functional analysis of soil moisture, relationship between soil water and crop growth at the wind-water erosion crisscross region in the northern Loess Plateau.展开更多
In this paper, we obtain optimum allocation of replaceable and repairable components in a system design. When repair and replace time are considered as random in the constraints. We convert probabilistic constraint in...In this paper, we obtain optimum allocation of replaceable and repairable components in a system design. When repair and replace time are considered as random in the constraints. We convert probabilistic constraint into an equivalent deterministic constraint by using chance constrained programming. We have used the selective maintenance policy to determine how many components to be replaced & repaired within the limited maintenance time interval and cost. A Numerical example is presented to illustrate the computational procedure and problem is solved by using LINGO Software.展开更多
Gymnastics is a discipline that has some factors that differentiate from other sports, such as: force, postural control on movement, extreme range of motion, and of the body expression. The objec- tive of the present ...Gymnastics is a discipline that has some factors that differentiate from other sports, such as: force, postural control on movement, extreme range of motion, and of the body expression. The objec- tive of the present paper was to compare: somatotype, body composition and energy availability in female gymnasts students in search for a better sport performance. We evaluated 24 healthy female children aged 7 - 12 years by means of a nutritional and anthropometric examinations, somatotype and body composition calculation, and energy availability measurement. We observed a low consumption of real calories intake, carbohydrates, and low amount of the real body weight mesurements among gymnatics students. Mesomorphic and ectomorfic somatotypes were the more frequent somatotypes found. Moreover, we saw significant differences in body composition and in energy availability among the differente somatotypes in student of gymnastics. Differences were located between endomorphic, mesomorphic, and ectomorphic somatotype groups in body composition while in energy availability were among mesomorphic-ectomorphic, and between endomorphic-ectomorphic groups. In conclusion, our data had important implications for per- formance of gymnastics in students and were discussed here.展开更多
In this paper, we study availability and profit optimization of a series-parallel system consisting of three subsystems A, B and C in which A and B are cold standby. Subsystem A consists of linear consecutive k-out-of...In this paper, we study availability and profit optimization of a series-parallel system consisting of three subsystems A, B and C in which A and B are cold standby. Subsystem A consists of linear consecutive k-out-of-n units while subsystems B and C consist of a single unit each. The system works if any of A or B and C work. The objective of this study is to maximize the steady-state availability and profit. To solve the optimization problem, different numbers of units for n = 2, 3, 4, 5 in subsystem A are considered. Explicit expressions for busy period of repairmen, steady-state availability and profit function are derived using linear first order differential equations. Several cases are analyzed graphically for n = 2, 3, 4, 5 to investigate the effects of various system parameters on availability and profit. The paper also presents graphical comparison for specific values of system parameters and finds that the optimal system configuration is when n = 5.展开更多
基金The study was supported by the National Natural Science Foundation of China–Shandong Joint Fund(No.U1706226)the National Natural Science Foundation of China(No.52171284).
文摘With the goal of evaluating the wave and wave energy conditions in the Philippines,the simulated wave nearshore(SWAN)model was used to estimate the wavefield using 30 years of cross-calibrated multi-platform(CCMP)wind field data(1987-2016).The spatiotemporal patterns of annual and monthly averaged significant wave heights and wave energy in the Philippines were analyzed based on the simulated data.Results showed that they had similar values;in particular,significant wave heights and wave energy were smaller in the south and southwest and higher in the north and northeast.A total of 12 representative points along the Philippine coast were selected to draw wave and wave energy roses.A directional analysis showed that the dominant wave was in the north north-east(NNE),northeast(NE),and east north-east(ENE)directions.Wave energy was mainly distributed in regions with an energy period between 1 and 10 s and significant wave heights between 0 and 4 m.To better utilize wave energy data in the Philippines,this paper studied the available and rich area of wave energy and analyzed the annual and monthly variability index of wave energy in the country.Moreover,the available significant wave heights of wave energy conversion devices(WECs)were set as 0.5-4 m,and the maximum annual average available wave energy occurred in the eastern Philippine Sea area,reaching 13 kW m^(-1).For the safety of WECs,extreme typhoon-induced wave conditions must be considered.Furthermore,the results showed that the maximum significant wave height and mean period over the 50-year return period reached 18 m and 15 s,respectively.
文摘Background: Malaria remains a major cause of morbidity and mortality in Zambia, affecting all levels of society, with children under the age of five and pregnant women being most at risk of serious illness. The availability of antimalarial medicines is one of the key interventions of malaria management. This study assessed the availability of antimalarial medicines in community pharmacies in Lusaka district, Zambia. Materials and Methods: This was a cross-sectional study that was conducted among 210 community pharmacies from September to November 2022 using a well-structured checklist in selected areas of Lusaka district. The availability was verified by a physical check of the product. The checklist contained the medicines listed both in the guidelines for diagnosis and treatment of malaria in Zambia as well as in the World Health Organization (WHO) malaria treatment guidelines. Results: This study found that all antimalarials listed in the local treatment guidelines for malaria were available in community pharmacies, though with the varying distribution. Of the 210 community pharmacies, 209 (99.5%) had artemether/lumefantrine in stock. The lowest available antimalarial was quinine/clindamycin, which was only available in 3 (1.4%) of the outlets. Conversely, 3 out of 16 (18.8%) antimalarials that were available in community pharmacies were not listed in the local treatment guidelines of malaria in Zambia, despite being listed in the WHO malaria treatment guidelines. This translated into a compliance level of 81.2% based on the local malaria treatment guidelines. Conclusion: This study concluded that antimalarials were available for all categories of malaria management in community pharmacies, though with a varying distribution. The presence of antimalarials not listed in the Zambian treatment guidelines is of public health concern which may have an impact on antimicrobial resistance in the future.
基金supported by the National Key Research and Development Program of China (2021YFF1000500)Major Program of Guangdong Basic and Applied Research (2019B030302006)+2 种基金the National Natural Science Foundation of China (32172659,32172658, 31872164)the STIC Grant (SGDX20210823103535007)the Natural Science Foundation of Guangdong Province of China(2021A1515010826, 2020A1515110261)。
文摘Nitrogen(N) and phosphorus(P) are two essential mineral nutrients for plant growth,which are required in relative high amount in plants.Plants have evolved a series of strategies for coordinately acquiring and utilizing N and P.However,physiological and molecular mechanisms underlying of N and P interactions remain largely unclear in soybean(Glycine max).In this study,interactions of N and P were demonstrated in soybean as reflected by significant increases of phosphate(Pi) concentration in both leaves and roots by N deficiency under Pi sufficient conditions.A total of four nitrogen limitation adaptation(NLA),encoding RING-type E3 ubiquitin ligase were subsequently identified in soybean genome.Among them,transcription of Gm NLA1-1 and Gm NLA1-3 was decreased in soybean by N starvation under Pi sufficient conditions,not for Gm NLA1-2.Suppression of all three Gm NLA1 members was able to increase Pi concentration regardless of the P and N availability in the growth medium,but decrease fresh weight under normal conditions in soybean hairy roots.However,comparted to changes in control lines at two N levels,N deficiency only resulted in a relatively higher increase of Pi concentration in Gm NLA1-1 or Gm NLA1-3 suppression lines,strongly indicating that Gm NLA1-1 and Gm NLA1-3 might regulate P homeostasis in soybean response to N starvation.Taken together,our result suggest that redundant and diverse functions present in Gm NLA1 members for soybean coordinate responses to P and N availability,which mediate P homeostasis.
基金supported by Major Special Project of Sichuan Science and Technology Department(2020YFG0460)Central University Project of China(ZYGX2020ZB020,ZYGX2020ZB019).
文摘To achieve the high availability of health data in erasure-coded cloud storage systems,the data update performance in erasure coding should be continuously optimized.However,the data update performance is often bottlenecked by the constrained cross-rack bandwidth.Various techniques have been proposed in the literature to improve network bandwidth efficiency,including delta transmission,relay,and batch update.These techniques were largely proposed individually previously,and in this work,we seek to use them jointly.To mitigate the cross-rack update traffic,we propose DXR-DU which builds on four valuable techniques:(i)delta transmission,(ii)XOR-based data update,(iii)relay,and(iv)batch update.Meanwhile,we offer two selective update approaches:1)data-deltabased update,and 2)parity-delta-based update.The proposed DXR-DU is evaluated via trace-driven local testbed experiments.Comprehensive experiments show that DXR-DU can significantly improve data update throughput while mitigating the cross-rack update traffic.
文摘This research article is based on a study of optimal frequency to the repairable system due to the failure finding interval to maximize as well as minimize the availability of some components devices. We studied together maintenance and corrective actions that carried out item of failure and periodic failure finding designed to check whether a system is still working. The model is proved as well as useful application in detecting the problem related to finding failure tasks of different scheme devices by maximization. The model formulated and the numerical application to the relevant mathematical model have been discussed to demonstrate the article quality. Therefore based on probability analytic development, the optimal maintenance policy is then obtained as solution of an optimization problem in which the maintenance cost rate is the objective function and the risk of corrective maintenance is the constraint function. Finally, the solution to the optimal device in the considered development model has been well adjusted due to derivation to the experimental observation rather than theory which will be taken into consideration in the next applied practical design research related and the system device provided that, the proactive device agreed with using the exponential distribution to the survive distribution function which can not be considered as valid.
文摘Unified identity authentication has become the basic information service provided by colleges and universities for teachers and students. Security, stability, high concurrency and easy maintenance are our requirements for a unified identity authentication system. Based on the practical work experience of China University of Geosciences (Beijing), this paper proposes a high availability scheme of unified identity authentication system based on CAS, which is composed of multiple CAS Servers, Nginx for load balancing, and Redis as a cache database. The scheme has been practiced in China University of Geosciences (Beijing), and the application effect is good, which has practical reference significance for other universities.
基金Project supported by the National Natural Science Foundation of Chi-na (No. 40432004, 40601086) the Natural Science Foundationof Zhejiang Province (No. Y504109).
文摘All the regulations that define a maximum concentration of metals in the receiving soil are based on total soil metal concentration. However, the potential toxicity of a heavy metal in the soil depends on its speciation and availability. We studied the effects of heavy metal speciation and availability on soil microorganism activities along a Cu/Zn contamination gradient. Microbial biomass and enzyme activity of soil contaminated with both Cu and Zn were investigated. The results showed that microbial biomass was negatively affected by the elevated metal levels. The microbial biomass-C (Cmic)/organic C (Corg) ratio was closely correlated to heavy metal stress. There were negative correlations between soil microbial biomass, phosphatase activity and NH4NO3 extractable heavy metals. The soil microorganism activity could be predicted using empirical models with the availability of Cu and Zn. We observed that 72% of the variation in phosphatase activity could be explained by the NH4NO3-extractable and total heavy metal concentration. By considering different monitoring approaches and different viewpoints, this set of methods applied in this study seemed sensitive to site differences and contributed to a better understanding of the effects of heavy metals on the size and activity of microorganisms in soils. The data presented demonstrate the relationship between heavy metals availability and heavy metal toxicity to soil microorganism along a contamination gradient.
基金This work was supported by a grant from Fund of Doctorial Programmes of State Educational Commission of China
文摘The availability of three dissolved organic phosphorus (DOP) compounds as nutrient sources for experimentalcultare of three algae was studied. Results indicated that these compounds could be utilized byalgae, and that dissolved inorganic phosphorus (DIP) was first to be uptaken when various forms ofphosphorus (DIP and DOP) co-existed. Dicrateria zhanjiangensis’ uptake of sodium glycerophosphatewas faster than that of D-ribose-5-phosphate. The increase of sodium glycerphosphate had little effecton the maximum uptake rate(V<sub>max</sub>) of Chlorella sp., but increased the semisaturation constant(K<sub>s</sub>) remarkably;the photosynthesis rates(PR) of Dicrateria zhanjiangensis and Chlorella sp. were rarely affected byusing various forms of phosphorus in the culture experiments. The possible DOP pathways utilizedby algae are discussed.
基金supported by the Key Knowledge Innovation Project of Chinese Academy of Sciences (KSCX2-YW-Z- 1020)the National Basic Research Program of China (2009CB825104)the National Natural Science Foundation of China (30970547)
文摘Eremosparton songoricum (Litv.) Vass is a dwarf clonal shrubby legume developed on the windward slopes of mobile or semi-fixed sand dunes of Central Asia. It is assumed that E. songoricum must possess a high degree of phenotypic plasticity for such a heterogeneous habitat. The variations of E. songoricum plants growing in two typical microhabitats (the upper slope and the lower slope of semi-mobile dune) were investigated. The morphological characteristics and the biomass allocation patterns were measured and compared at the clonal fragment level. Compared with the clonal fragment on the lower slope of dune, the clonal fragment on the upper slope of the dune (a) declined in total biomass and ramet height, (b) increased the length of rhizomes and the number of roots, (c) increased the degree of asym- metry, and (d) heightened allocation to the belowground biomass. Our results confirmed the hypothesis of high phenotypic adjustment capacity of E. songoricum to habitat moisture availability. Phenotypic plasticity of E. songoricum contributed to reduce the damage risk, led to an environmentally induced specialization in function of resources exploitation, resulted in its persistence in heterogeneous environments and was adaptive in sand dune environment.
基金supported by the National Key Research and Development Program of China (2016YFD03001093)the National Natural Science Foundation of China (31671626, 31771728)
文摘Soil with low phosphorus (P) availability and organic matter contents exists in large area of southwest of China, but some soybean genotypes still show well adaptations to this low yield farmland. However, to date, the underlying mechanisms of how soybean regulates soil P availability still remains unclear, like microbe-induced changes. The objective of the present study was to compare the differences of rhizosphere bacterial community composition between E311 and E109 in P-sufficiency (10.2 mg kg^-1) and P-insufficiency (5.5 mg kg^-1), respectively, which then feedback to soil P availability. In P-sufficiency, significant differences of the bacterial community composition were observed, with fast-growth bacterial phylum Proteobacteria, genus Dechloromonas, Pseudomonas, Massilia, and Propionibacterium that showed greater relative abundances in E311 compared to E109, while in P-insufficiency were not. A similar result was obtained that E311 and E109 were clustered together in P-insufficiency rather than in P-sufficiency by using principal component analysis and hierarchical clustering analysis. The quadratic relationships between bacterial diversity and soil P availability in rhizosphere were analyzed, confirming that bacterial diversity enhanced the soil P availability. Moreover, the high abundance of Pseudomonas and Massilia in the rhizosphere of E311 might increased the P availability. In the present study, the soybean E311 showed capability of shaping rhizosphere bacterial diversity, and subsequently, increasing soil P availability. This study provided a strategy for rhizosphere management through soybean genotype selection and breeding to increase P use efficiency, or upgrade middle or low yield farmland.
基金Sponsored bythe National Natural Science Foundation of China(70671009)the Postgraduate Science and Innovation Project of Beijing Instituteof Technology (GC200818)
文摘The new model for parallel repairable system is introduced, and it is based on the practice problems of maintenance and the idea of Ion-Channel modeling. In the new model, repair times that are sufficiently short (less than some critical value) do not result in system failure, and such a repair interval is omitted from the downtime record. Usually, the underlying process is Markov process if the durations of working and repair time have the negative-exponential distributions, but the new system has not the Markov properties, which is worth to study. The reliability indexes such as instantaneous availability and steady-state availabilities for the new system are given through probability analysis. A numerical example is given to illustrate the results.
文摘One hundred and forty-four Avin broilers (1 d of age) were randomly divided into six groups, with three replicates of eight birds each to study on the effects of different oligosaccharides on performance and availability of nutrients in broilers. The control group(Group I)was fed with corn-soybean meal as basal diet, and the trial groups (Group II, III, IV,V and VI) were fed with basal diet plus 0.1% Manoligosaccharides(MOS), 0.3% Soybean-Oligosaccharides(SBOS), 0.3% Fructo-oligosaccharides(FOS), 0.3% α-Glucooligosaccharides(α-GOS) and 50 mg·L-1 Chlortetracycline(CTC), respectively. The results showed that the supplementation of oligosaccharides slightly improved daily gain and feed intake. SBOS supplementation improved, but MOS and α-GOS significantly decreased availability of energy. Oligosaccharides supplementation improved availability of energy, phosphorus, calcium, magnesium and iron, and significantly increased cholesterol content of fecal, and did not affect on availability of protein and cholesterol contents in serum and muscle. Availability of phosphorus of broilers fed with FOS was much higher than that with α-GOS. SBOS supplementation remarkably increased availability of iron.
基金Supported by Program for Liaoning Innovative Talents in University(Grant No.LR2017070)National Natural Science Foundation of China(Grant No.51505207)+1 种基金Open Foundation of Zhejiang Provincial Top Key Academic Discipline of Mechanical Engineering(Grant No.ZSTUME02A01)National Natural Science Foundation of China(Grant No.U1708255)
文摘Conventional reliability models of belt drive systems in the failure mode of fatigue are mainly based on the static stress strength interference model and its extended models, which cannot consider dynamic factors in the operational duration and be used for further availability analysis. In this paper, time-dependent reliability models, failure rate models and availability models of belt drive systems are developed based on the system dynamic equations with the dynamic stress and the material property degradation taken into account. In the proposed models, dynamic failure dependence and imperfect maintenance are taken into consideration. Furthermore, the issue of time scale inconsistency between system failure rate and system availability is proposed and addressed in the proposed system availability models. Besides, Monte Carlo simulations are carried out to validate the established models. The results from the proposed models and those from the Monte Carlo simulations show a consistency. Furthermore, the case studies show that the failure dependence, imperfect maintenance and the time scale inconsistency have significant influences on system availability. The independence assumption about the belt drive systems results in underestimations of both reliability and availability. Moreover, the neglect of the time scale inconsistency causes the underestimate of the system availability. Meanwhile, these influences show obvious time-dependent characteristics.
基金supported by the National Natural Science Foundation of China(7120116671201170)
文摘This paper considers a project scheduling problem with the objective of minimizing resource availability costs appealed to finish al activities before the deadline. There are finish-start type precedence relations among the activities which require some kinds of renewable resources. We predigest the process of sol-ving the resource availability cost problem (RACP) by using start time of each activity to code the schedule. Then, a novel heuris-tic algorithm is proposed to make the process of looking for the best solution efficiently. And then pseudo particle swarm optimiza-tion (PPSO) combined with PSO and path relinking procedure is presented to solve the RACP. Final y, comparative computational experiments are designed and the computational results show that the proposed method is very effective to solve RACP.
基金Norwegian University of Science and Technology(Project 43255)
文摘Passive Optical Networks(PONs)are considered as the preferred solution for broadband fibre-based access networks.This is because PONs present low cost deployment,low energy consumption and also meet high bandwidth demands from end users.In addition,end users expect a high availability for access networks,while operators are more concerned about reducing the failure impact(number of clients affected by failures).Moreover,operators are also interested in reducing the cost of the access network.This paper provides a deep insight into the consequences that the physical topology and design decisions cause on the availability,the failure impact and the cost of a PON.In order to do that,the physical layout of the PON deployment area is approximated by a network geometric model.A PON deployed according to the geometric model is then assessed in terms of failure impact,availability and cost.This way,the effects of different design decisions and the physical layout on these three parameters are evaluated.In addition,the tradeoffs between availability,failure impact and cost caused by planning decisions and the physical topology are identified and pinpointed.
基金support from the National Natural Science Foundation of China(41101296)the Key Technologies R&D Program of China during the 12th Five-Year Plan period(2012BAD14B02)
文摘Fungi capable of arsenic(As) accumulation and volatilization are hoped to tackle As-contaminated environment in the future. However, little data is available regarding their performances in field soils. In this study, the chlamydospores of Trichoderma asperellum SM-12F1 capable of As resistance, accumulation, and volatilization were inoculated into As-contaminated Chenzhou(CZ) and Shimen(SM) soils, and subsequently As volatilization and availability were assessed. The results indicated that T. asperellum SM-12F1 could reproduce well in As-contaminated soils. After cultivated for 42 days, the colony forming units(cfu) of T. asperellum SM-12F1 in CZ and SM soils reached 10^10–10^11 cfu g^–1 fresh soil when inoculated at a rate of 5.0%. Inoculation with chlamydospores of T. asperellum SM-12F1 could significantly accelerate As volatilization from soils. The contents of volatilized As from CZ and SM soils after being inoculated with chlamydospores at a rate of 5.0% for 42 days were 2.0 and 0.6 μg kg^–1, respectively, which were about 27.5 and 2.5 times higher than their corresponding controls of no inoculation(CZ, 0.1 μg kg^–1; SM, 0.3 μg kg^–1). Furthermore, the available As content in SM soils was decreased by 23.7%, and that in CZ soils increased by 3.3% compared with their corresponding controls. Further studies showed that soil p H values significantly decreased as a function of cultivation time or the inoculation level of chlamydospores. The p H values in CZ and SM soils after being inoculated with 5.0% of chlamydospores for 42 days were 6.04 and 6.02, respectively, which were lowered by 0.34 and 1.21 compared with their corresponding controls(CZ, 6.38; SM, 7.23). The changes in soil p H and As-binding fractions after inoculation might be responsible for the changes in As availability. These observations could shed light on the future remediation of As-contaminated soils using fungi.
基金Supported by the National Natural Science Foundation of China(NSFC)(41271046)Postdoctoral Science Foundation of China(Oversea scholar,87328)+1 种基金Heilongjiang Provincial Department of Education Scientific Research Foundation for overseas scholars,China(1251H017)Scientific Research Foundation of Northeast Agricultural University of China(115-180152)
文摘The objectives of the current study were to estimate evapotranspiration(ET) over the grassland and assess seasonal variation of moisture availability at the wind-water erosion crisscross region in the northern Loess Plateau of China. The Liudaogou Catchment which has the representative climatic and hydrological characteristics of the wind-water erosion crisscross region was chosen as the study location. The reference crop evapotranspiration(ET 0) was estimated by Penmen method, which was recommended by FAO56 and the evapotranspiration over the grassland(ET) was estimated by Penmen-Monteith equation using the observed meteorological data with time unit of 1 h. The soil moisture availability factor was defined by m a =ET/ET 0. The calculated results for 2006 indicated that the total ET 0 was slightly more than the total yearly precipitation and ET accounted for 37 % of that, ET increased distinctly after the intensive rainfall event in the rainy season. Most of the m a was less than 0.4 and its annual mean was 0.34. It was expected that the results provided a basis for studies on dynamic functional analysis of soil moisture, relationship between soil water and crop growth at the wind-water erosion crisscross region in the northern Loess Plateau.
文摘In this paper, we obtain optimum allocation of replaceable and repairable components in a system design. When repair and replace time are considered as random in the constraints. We convert probabilistic constraint into an equivalent deterministic constraint by using chance constrained programming. We have used the selective maintenance policy to determine how many components to be replaced & repaired within the limited maintenance time interval and cost. A Numerical example is presented to illustrate the computational procedure and problem is solved by using LINGO Software.
文摘Gymnastics is a discipline that has some factors that differentiate from other sports, such as: force, postural control on movement, extreme range of motion, and of the body expression. The objec- tive of the present paper was to compare: somatotype, body composition and energy availability in female gymnasts students in search for a better sport performance. We evaluated 24 healthy female children aged 7 - 12 years by means of a nutritional and anthropometric examinations, somatotype and body composition calculation, and energy availability measurement. We observed a low consumption of real calories intake, carbohydrates, and low amount of the real body weight mesurements among gymnatics students. Mesomorphic and ectomorfic somatotypes were the more frequent somatotypes found. Moreover, we saw significant differences in body composition and in energy availability among the differente somatotypes in student of gymnastics. Differences were located between endomorphic, mesomorphic, and ectomorphic somatotype groups in body composition while in energy availability were among mesomorphic-ectomorphic, and between endomorphic-ectomorphic groups. In conclusion, our data had important implications for per- formance of gymnastics in students and were discussed here.
文摘In this paper, we study availability and profit optimization of a series-parallel system consisting of three subsystems A, B and C in which A and B are cold standby. Subsystem A consists of linear consecutive k-out-of-n units while subsystems B and C consist of a single unit each. The system works if any of A or B and C work. The objective of this study is to maximize the steady-state availability and profit. To solve the optimization problem, different numbers of units for n = 2, 3, 4, 5 in subsystem A are considered. Explicit expressions for busy period of repairmen, steady-state availability and profit function are derived using linear first order differential equations. Several cases are analyzed graphically for n = 2, 3, 4, 5 to investigate the effects of various system parameters on availability and profit. The paper also presents graphical comparison for specific values of system parameters and finds that the optimal system configuration is when n = 5.