Search

In this work,ultrasound was used for treating sludge,and released organics was used as electron donors for accelerating quinoline biodegradation.Flask experimental results showed that quinoline removal rates are proportional to the biomass of treated and untreated sludge,but 25% untreated sludge and 75% treated sludge were mixed for quinoline biodegradation to achieve the fastest removal rate,during which treated sludge played the role of electron donor mainly,and untreated sludge played the role bio-catalyzer.Electron balance was carried out to show that 18 mL supernatants of treated sludge played the same role of 3.65 mmol/L oxalate for accelerating quinoline biodegradation.

Background: In recent years, with the further research of human genome scanning, the relationship between matrix metalloproteinase-9 (MMP-9) gene polymorphisms and many diseases has aroused increased attention. But there is little research on the relationship between MMP-9 gene polymorphisms and ischemic stroke (IS). This study was conducted to evaluate the relationships between the rs3918242 and rs17577 polymorphisms in the MMP-9 gene and IS in a Chinese population. Methods: 152 cases of IS patients and 152 healthy controls were enrolled in this study. All subjects were genotyped for the MMP-9 rs3918242 and rs17577 polymorphisms by polymerase chain reaction (PCR) coupled with restriction fragment length polymorphism (RFLP) and restriction analysis. Results: Rs3918242 showed genotypes TT, TC, and CC, and rs17577 exhibited genotypes AA, AG, and GG. The MMP-9 polymorphisms rs3918242 and rs17577 exhibited complete linkage. Our study found there was no significant difference in genotype and allele between rs3918242 and rs17577 between patients and controls. The MMP-9 gene rs3918242 and rs17577 polymorphisms are not significantly correlated with IS risk. Genetic polymorphisms vary among ethnic and regional populations. Conclusion: Our results suggest that MMP-9 rs3918242 is completely linked to rs17577, while the rs3918242 and rs17577 polymorphisms are not significantly associated with the risk of IS. Genetic polymorphisms vary among ethnic and regional populations.

In this study, we constructed ditches across the slope of the land between two rows of jujube trees, which were filled with crushed biological material to harvest rainfall, named bamboo-style water harvesting ditches (BWHDs). We analyzed the soil moisture content of BWHD at three sampling points between July and September while the level bench terrace was used as the control. We found that the mean overall moisture content, soil water storage, and vertical profile of 0 to 200 cm (0 to 78.7 in) of BWHDs was higher than the control throughout the observation period. The mean BWHD soil moisture content of the three sampling points was in the order: middle > top > bottom. The difference between the middle position and the top or bottom was highly significant (P top > bottom, whereas that in the deeper layer was: middle > bottom > top. A comparison of the different layers showed that the overall soil moisture content was highest in the surface BWHD layer, although there was a decreasing trend from the end of July until the end of September. The middle layer was higher than the deeper layer and it was relatively stable throughout the observation period. The deeper layer was lowest, although there was an increasing trend. Therefore, BWHD improved the soil moisture level compared with the control, and had better application and popularization value as a new measures in the Hilly Loess Region of China.

Pear jujube(Ziziphus jujuba Mill.) as a common tree crop in the Loess Plateau region ofChina,but its ecological and economic benefits have failed to be fully realized because of the shortage of water resources.Therefore,improving jujube yield and water use efficiency are key goals.Studies of the water deficit index and water consumption rules can help to design more optimal irrigation systems and improve water use efficiency.In 2010 and 2011,we studied the water consumption of 4-year-old jujube plants subjected to one of four soil water treatments during their flowering and fruit development periods.We analyzed the correlation of water consumption to variation in trunk diameter and established a regression model.Our goal was to determine how pear jujube stem diameter responded to water conditions during the flowering and fruit development periods to determine a suitable water deficit index to use in building irrigation systems.The flowering and fruit development periods of pear jujube are critical water demand periods.Because these two processes define the main period of reproductive growth,they determine the quantity,volume,weight,and yield of fruit.Stem diameter change indexes included daily mean trunk diameter(MTD),daily maximum trunk diameter(MXTD),maximum daily shrinkage in trunk diameter(MDS),and daily growth of stem diameter(DG).The results indicated that(1) the tree water use increased with an increase in soil water content.Regardless of the treatment differences in soil water conditions,the maximum daily water use all occurred during the week following irrigation,and water consumption during the fruit expansion stage was greater than in flowering and fruit set stages.(2) Two years of experimental data proved that the logistic function could precisely express the changes in MTD and MXTD in the critical water demand periods of jujube,so these two indexes were equivalent in terms of assessing jujube trunk diameter growth during the study period,even though the growth rate varied annually and among treatments.(3) Under the high-water treatment,the indices derived from the trunk diameter(MTD,MXTD,MDS,and DG) were not sensitive to water consumption,while in the low-water treatment,MDS had a highly significant correlation with daily water use compared with the other indexes,indicating its potential as an indicator of jujube water consumption under water deficit conditions.The regression model between water consumption and trunk diameter that we established can be used to analyze the sensitivity of stem diameter variation to water deficit and to detect the water consumption status of pear jujube trees.

The regulation of water consumption by mountain jujube trees,jujube pear-like,has not been previously researched in a systematic fashion because of differences among the jujube samples,including age,variety,canopy morphology,meteorological conditions,and land surface conditions.Numerical simulation is an effective and convenient method to investigate the patterns of water consumption of trees,including jujube trees.Therefore,this paper introduces a mathematical model(HYDRUS-1D) to simulate the soil moisture requirements for jujube pear-like. First,to develop the model,the forecast parameters of the HYDRUS-1D model,such as soil properties,weather conditions,leaf area index(LAI),root distribution,and basal crop coefficient,were measured in the northern hilly area of Shannxi Province,China,from 2008 to 2010.Second,the dynamic characteristics of soil moisture in a rain-proof plot experiment were roughly simulated using the HYDRUS-1D model,then,we adjusted the model so that the simulated results better fit the measured data of soil moisture.We inversely extrapolated the parameters of soil water stress coefficient and extinction coefficient,which determine the values of the potential transpiration and potential evaporation,respectively,for the atmospheric boundary conditions.Finally,using the parameters we estimated,we used the HYDRUS-1D model to predict water consumption by eight-year-old jujube pear-like trees in the field. The results showed the following.(1) The changes in LAI of jujube pear-like were consistent with a Gaussian function from germination to fruit ripening.Average LAI of jujube pear-like increased from young to old trees,but the inter-annual differences in LAI decreased in trees that were older than six years.(2) Root depth of jujube pear-like increased linearly with the age of the tree.At the same time,the distribution of capillary roots decreased linearly with an increase in the root depth.The percentage of capillary roots at a depth of 40 cm was more than 70%.(3) To obtain the boundary conditions of the HYDRUS-1D model,we used LAI and the extinction coefficient combined with the crop coefficient to calculate the daily reference evapotranspiration.Fitting the model to the data indicated that,when extinction coefficient of mountain jujube pear-like was 0.52,the measured data of soil moisture fit the simulation quite well.(4) The correlation coefficient of simulated values and measured data of soil water storage reached 0.89,which proved that the parameters of the model with respect to water consumption of jujube pear-like were reliable and that the HYDRUS-1D model could simulate well the dynamic process of soil moisture changes and accurately estimate the water requirements of jujube pear-like.(5) As a result,cumulative evaporation of mountain jujube pear-like was 92 mm,and cumulative transpiration was 175 mm.The total water volume consumed by eight-year-old jujube pear-like trees,from germination to harvest,was 267 mm.Based on the actual amounts of local rainfall and water resources,jujube pear-like should be irrigated two to three times during its flowering and fruiting periods,and water application depths should reach 30—40 mm to meet the growth requirements of this crop plant.

The jujube industry is highly developed in the Yulin district of northern Shaanxi Province.Because jujube fruit yield is often affected by variation in precipitation throughout the year,accurate irrigation is an important method for increasing the potential of the local jujube industry. Water demand in jujube trees is most critical during two stages: 1) anthesis and fruit set and 2) fruit development.In this study,the effect of different ecological factors,such as soil water potential(WPs),solar radiation(Rs),air temperature(Ta),and air relative humidity(RH),on jujube trunk diameter(TD) contraction during fruit development was investigated.In addition,the most suitable indicator of TD contraction was determined for use in accurate irrigation management. Research was conducted in a rainproof shed at the micro-irrigation demonstration station in Mengcha,Yinzhou,Mizhi,Yulin,China.Three-year-old pear-jujube trees were studied using four different WPs treatments:-41 to-51 kPa(T1),-68 to-84 kPa(T2),-96 to-135 kPa(T3),and-311 to-390 kPa(T4).Individual test plots,separated by cement enclosures and containing three jujube trees,were 6 m long × 1 m wide × 1 m high.Each treatment was applied to three test plots.WPs was monitored continuously with an EQ15 equilibrium tensiometer and controlled automatically using a drip irrigation system that supplied water whenever WPs reached a minimum value.TD was continuously measured with a linear variable displacement transducer(LVDT);atmospheric factors were recorded using an automated weather station.Collected data were analyzed using DPS statistics software,and figures and tables were generated with Excel. The results showed that jujube TD contraction followed a U-shaped curve over the course of a day.In general,trunk diameter shrank during the day,reaching a minimum trunk diameter(MNTD) at 17:00-19:00;at night,trunk diameter expanded,with the maximum diameter(MXTD) occurring at 7:00-9:00.The interval between MNTD and MXTD was about 12 h.TD trended differently depending on growing period,weather,and WPs treatment.During fruit development,when WPs ranged from-41 to-390 kPa,TD increased with increasing WPs.MXTD was significantly different between the treatments,and higher WPs ranges resulted in increased trunk diameter.MXTD was an appropriate water-level diagnostic indicator at this stage.Trunk diameter growth(DG) increased at moderate WPs levels(T2 and T3),but was inhibited when WPs was excessively high(T1) or low(T4).DG was also influenced by weather conditions,increasing greatly on rainy days because of the higher RH.In contrast,the TD daily shrinking range was larger on sunny days,with no increase observed on rainy days.TD had a significant positive correlation with RH(correlation coefficient ca.0.9) and a significant negative correlation with Ta(correlation coefficient ca.-0.75),but little correlation with Rs.Thus,RH and Ta were the major atmospheric factors influencing TD contraction.Overall,jujube TD contraction was influenced simultaneously by various ecological factors,most significantly RH,Ta,and WPs.At higher WPs ranges,WPs had the greatest direct influence on TD contraction,followed by RH;at lower WPs ranges,RH was the primary factor,followed by WPs.TD was not directly affected by Ta,regardless of WPs level.

Pear jujube(Ziziphus jujuba Mill.grafted on wild jujube) is widely cultivated in the Loess Plateau region of China.However,pear jujube culture has been constrained by the wasteful use of limited water supplies that characterizes traditional irrigation,which has restricted the development of local agriculture.Thus,there is a need to develop new irrigation scheduling techniques that optimize water use.This paper aimed to determine a suitable soil water potential measure based on pear jujube tree responses to different soil water potentials during the fruit development period in the Loess Plateau.Fruit development is divided into two periods,i.e.,the slow-growing fruit stage,where the main fruit process is cell differentiation,and the fast-growing fruit stage,when the cells expand.Four soil water potential levels were tested with four-year-old pear jujube trees.It was found that the maximum daily trunk diameter increased slowly during the slow-growing fruit stage while high soil water potential decreased the proportion of fruit abscission.The fruit abscission rate decreased significantly when the soil water potential was higher than-84 kPa.The maximum daily trunk diameter and relative leaf water content indicated the pear jujube water content during the fast-growing fruit stage.Thus,higher soil water potential resulted in a greater maximum daily trunk diameter and increased relative leaf water content.Furthermore,the percentage of fruit abscission was negative,i.e.,fruit set number exceeded fruit abscission,when the soil water potential varied in the range of-41 kPa to-51 kPa during the fast-growing fruit stage.Fruit setting occurred in treatments where the soil water potential was higher than-84 kPa,whereas trees did not set fruit after receiving full irrigation that produced a soil water potential of-461 kPa in early experiments.However,fruit that set during the fast-growing fruit stage were always small because they had less time to grow.Thus,the single fruit weight with a full irrigation treatment was lower than other treatments.The soil water potential was similar to the control treatment after drought stress(-461 kPa),but leaf photosynthetic function and chlorophyll content were affected,i.e.,the leaf photosynthetic function was decreased and the chlorophyll content was the lowest among all treatments.The low chlorophyll content decreased the leaf photosynthetic function.We found that mild controlling the soil water content could increase the single fruit weight with no effect on production.This study showed that a suitable soil water potential during the fruit development period was-41 kPa to-84 kPa,because this treatment increased the leaf water use efficiency and the single fruit weight,which compensated for the lower number of fruit.

Loess Plateau is a typical rain-fed farming region, facing the threat of drought. Irrigation method is among the most important factors affecting jujube quality. This study investigated the response of Ziziphus jujuba Mill. cv. Lizao quality to three different irrigation methods (drip-, pipe- and surge spring root irrigation) combining two water levels (20 m(3)/hm(2) and 120 m(3)/hm(2)). The effects of the trials were evaluated by taking into account the physical-chemical characteristics of jujubes and the antioxidant activity. Concomitant to this, the concentration of some taste-related (viz. glucose, fructose, TSS and malic acid) and health-related compounds/parameters (viz. catechin and epicatechin) were generally much greater in jujube fruit treated with drip irrigation (120 m(3)/hm(2)). Different irrigation treatments had no significant effects on antioxidant capacity, total phenolics and proanthocyanidins (except for pipe irrigation 20 m(3)/hm(2)). The best compromise between quality and irrigation of jujube fruit was achieved with drip irrigation (120 m(3)/hm(2)).