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Soil hydraulic properties are basic inputs for simulating water and solute transport in the vadose zone. Many methods have been developed to directly measure or indirectly estimate soil hydraulic properties. However, low-cost, simple and robust methods are still scarce even in a laboratory. Here we present a new analytical method, based on an approximate solution to the one-dimensional vertical infiltration problem that can be used to determine Brooks-Corey model parameters. Measurements include cumulative infiltration, wetting front advance with time, and initial and final upper boundary water contents, during a one-dimensional vertical infiltration experiment. Infiltration experiments with twelve disturbed soils were performed to test the new method. The results indicated that the estimated saturated hydraulic conductivities from transient infiltration processes were consistent with those measured with a constant-head method. The estimated soil water retention curves (SWRCs) by the analytical method for the twelve soils were in agreement with those measured by a direct method in which soil water potentials were measured through tensiometers. The root mean square error (RMSE) of the estimated soil water contents by the new method were less than 0.045 cm3 cm-3 for the twelve soils. Compared to most direct methods, the new method is inexpensive, rapid and easy to use, and thus can be a substitute for direct methods in a laboratory. Although how to monitor representative wetting front remains unsolved, the new method has a potential for use in the future in determining in situ soil hydraulic properties where lateral flows are negligible. [ABSTRACT FROM AUTHOR]

The Green--Ampt model (GAM) is a widely used water infiltration model. However, it lacks a reliable theoretical basis to independently and simultaneously determine the GAM parameters of effective hydraulic conductivity (Ke ) and the average matric pressure head at the wetting front (Hf ) from those commonly measured soil hydraulic properties. In this paper, we derived an approximate analytical solution similar to GAM for one-dimensional vertical infiltration into soils with initially uniform soil moisture distribution, with Ke and Hf being simultaneously related to the Brooks--Corey (BC) model parameters. The new relationships are not restricted to the piston-type moisture profile or delta-type water diffusivity like in the traditional GAM (TGAM). Infiltration experiments on three soils of various textures were conducted to validate the new approximate analytical solution and the corresponding GAM parameters. It was demonstrated that the predicted cumulative infiltrations and soil moisture profiles by the GAM with Ke and Hf calculated by the new expressions (new GAM, NGAM) generally agreed well with the numerical solutions, especially for initially dry soils. In contrast, cumulative infiltrations were considerably over-predicted by the TGAM using Ke = Ks and Hf calculated by Neuman's equation. Our theoretical analysis further indicated that even without air entrapped during infiltration, the effective hydraulic conductivity can still be less than the saturated hydraulic conductivity Ks . The relative effective hydraulic conductivity ζ (Ke/Ks ) and the relative average matric pressure head at the wetting front η (-Hf/hd where hd is absolute value of the air-entry suction) show a dependency only on soil pore structure index (n) and effective initial soil-water saturation (Si ). The values of ζ increased but η decreased with Si and n. The theoretical ranges of ζ and η were from 0.5 and 2 for dry heavy-texture soils to 1 and 0 for saturated soils, respectively, which are consistent with the experimental values reported in literatures. [ABSTRACT FROM AUTHOR]

In this study, a regional irrigation schedule optimization method was proposed and applied in Fengqiu County in the North China Plain, which often suffers serious soil water drainage and nitrogen (N) leaching problems caused by excessive irrigation. The irrigation scheduling method was established by integrating the 'checkbook irrigation method' into a GIS-coupled soil water and nitrogen management model (WNMM) as an extension. The soil water and crop information required by the checkbook method, and previously collected from field observations, was estimated by the WNMM. By replacing manually observed data with simulated data from WNMM, the application range of the checkbook method could be extended from field scale to regional scale. The WNMM and the checkbook irrigation method were both validated by field experiments in the study region. The irrigation experiment in fluvo-aquic soil showed that the checkbook method had excellent performance; soil water drainage and N leaching were reduced by 83.1 and 85.6%, respectively, when compared with local farmers' flood irrigation. Using the validated WNMM, the performance of checkbook irrigation in an entire winter wheat and summer maize rotation was also validated: the average soil water drainage and N leaching in four types of soils decreased from 331 to 75 mm year and 47.7 to 9.3 kg hayear, respectively; and average irrigation water use efficiency increased from 26.5 to 57.2 kg ha mm. The regional irrigation schedule optimization method based on WNMM was applied in Fengqiu County. The results showed a good effect on saving irrigation water, decreasing soil water drainage and then saving agricultural inputs. In a typical meteorological year, it could save >110 mm of irrigation water on average, translating to >7.26 × 10 m of agricultural water saved each year within the county. Annual soil water drainage was reduced to <143 mm and N leaching to <27 kg ha in most soils, all of which were significantly lower than local farmers' flood irrigation. In the mean time, crop yield also had an average increase of 2,890 kg ha when checkbook irrigation was applied. [ABSTRACT FROM AUTHOR]

The Green-Ampt equation is often used to estimate infiltration in hydrologic modeling. Only a few of the currently used simulation models, however, can simulate infiltration into a heterogeneous soil with nonuniform initial soil water content by the Green-Ampt equation during nonsteady rainfall. In this study, we derived an infiltration model for layered soils under nonsteady infiltration based on the Green-Ampt method (Green-Ampt for Layered Soils, or GALS). In the GALS model, a formula for estimating average suction (5) was derived to include initial soil water effect, and the soil profile was divided into several layers to consider both soil texture and initial soil moisture effects on infiltration. The new model can predict infiltration capacity, ponding time, and cumulative infiltration. Three infiltration experiments, steady-state infiltration into a layered soil with nonuniform initial soil water content, nonsteady infiltration into a layered soil with uniform soil water content; and nonsteady-state infiltration into a layered soil with nonuniform soil water content, were conducted for model testing. Comparison showed that the GALS model was in good agreement with another Green-Ampt-based model and the measured data. [ABSTRACT FROM AUTHOR]

In this experiment, when the strontium chloride–citrate acid extractant (0.02 M SrCl 2 –0.05 M citrate) was used for extraction of calcareous soils with calcium carbonate greater than 70 g kg -1 , the filtrate was turbid. Furthermore, white precipitation appeared when this extract was used for phosphorus determination with the Murphy and Riley method. As the concentration of citrate in strontium chloride–citrate acid extractant decreased to 0.025 or 0 M , the filtrate became clean. Further experiments indicated that the 0.02 M SrCl 2 extractant could be used as a universal extractant for soil nitrate+nitrite and potassium; the extracted nitrate+nitrite and potassium significantly correlated with nitrogen and potassium phytoavailability, respectively, determined with ryegrass pot experiment ( P [ABSTRACT FROM AUTHOR]

The loess region in northern China is an important area of apple ( Pyrus malus L.) and pear ( Pyrus communis L.) production due to its favorable soil and climate. In recent years, as the apple and pear production in this region rapidly increased, more orchards experienced iron deficiency chlorosis. However, information on soil nutrient status and fruit tree chlorosis of this region is scarce. In this research, we collected soil and fruit tree leaf samples from 25 pear and apple orchards (10 chlorotic orchards and 15 nonchlorotic orchards). Soil samples were collected at depths of 0–20 cm, 20–40 cm, 40–60 cm, and 60–80 cm. Soil organic matter, total nitrogen (TN), alkali-hydrolyzable N, Olsen-phosphorus (P), ammonium acetate-potassium (K), DTPA-iron (Fe), and less than 0.01-mm soil particle content were analyzed, soil bulk density of 0–10 cm, 10–20 cm, 20–30 cm, and 30–40 cm were also determined. Leaf samples were analyzed for chlorophyll content. Comparison of soil properties was performed between chlorotic orchard soils and nonchlorotic orchard soils; stepwise multiple regression was performed between leaf chlorophyll content and soil properties. The results indicated that those orchard soils were rich in P and K but deficient in Fe. Chlorotic orchard soils contained more K, bicarbonate and less than 0.01-mm soil particles, and less DTPA-Fe in certain layers than those of nonchlorotic orchard soils. Leaf chlorophyll content negatively correlated with soil bicarbonate, alkali-hydrolysable N, and ammonium acetate-K and positively correlated with TN, DTPA-Fe, and bulk density at certain depths. Most of these soil properties that have a significant difference between these two kinds of orchard soils or affect leaf chlorophyll content occur below 40 cm in the soil profile. These results suggested that high bicarbonate content and low available Fe content in soils were the primary causes for fruit tree chlorosis in the loess region. Shallow groundwater table in the chlorotic orchards and root growth impairment in the surface soil because of tillage are supposed to be the reason why deeper depth in soil profile play an important role in fruit tree chlorosis in this region. [ABSTRACT FROM AUTHOR]

Nonlinear least squares algorithm is commonly used to fit the evaporation experiment data and to obtain the 'optimal' soil hydraulic model parameters. But the major defects of nonlinear least squares algorithm include non-uniqueness of the solution to inverse problems and its inability to quantify uncertainties associated with the simulation model. In this study, it is clarified by applying retention curve and a modified generalised likelihood uncertainty estimation method to model calibration. Results show that nonlinear least squares gives good fits to soil water retention curve and unsaturated water conductivity based on data observed by Wind method. And meanwhile, the application of generalised likelihood uncertainty estimation clearly demonstrates that a much wider range of parameters can fit the observations well. Using the 'optimal' solution to predict soil water content and conductivity is very risky. Whereas, 95% confidence interval generated by generalised likelihood uncertainty estimation quantifies well the uncertainty of the observed data. With a decrease of water content, the maximum of nash and sutcliffe value generated by generalised likelihood uncertainty estimation performs better and better than the counterpart of nonlinear least squares. 95% confidence interval quantifies well the uncertainties and provides preliminary sensitivities of parameters. [ABSTRACT FROM AUTHOR]

Artificial cyanophages are considered to be an effective biological method to control harmful cyanobacterial bloom. However, no synthetic cyanophage genome has been constructed and where its obstacles are unclear. Here, we survey a stretch of 16 kb length sequence of cyanophage A-4L that is unclonable in Escherichia coli. We test 12 predicted promoters of cyanophage A-4L which were verified all active in E. coli. Next, we screen for eight ORFs that hindered the assembly of intermediate DNA fragments in E. coli and describe that seven ORFs in the 16 kb sequence could not be separately cloned in E. coli. All of unclonable ORFs in high-copy-number plasmid were successfully cloned using low-copy-number vector, suggesting that these ORFs were copy-number-dependent. We propose a clone strategy abandoned the promotor and the start codon that could be applied for unclonable ORFs. Last, we de novo synthesized and assembled the full-length genome of cyanophage A-4L. This work deepens the understanding of synthetic cyanophages studies. [ABSTRACT FROM AUTHOR]

A 27-year field experiment with various fertilization regimes was chosen for evaluating how fertilization regimes influence soil denitrification potential (SDP), to determine whether the microbial mechanism of SDP variation varies with fertilization regimes. The results showed that the compost (OM) fertilizer treatment presented the highest SDP followed by half compost plus half chemical fertilizer (NPKOM) treatment. Both SDPs were 3-25 times higher than those of the other treatments, and the SDP was higher in the OM than NPKOM, indicating an increase in SDP with the application of compost. The higher SDPs from OM and NPKOM were closely associated with higher abundances of functional genes, and enrichments of Rubrivivax gelatinosus and Azospirillum sp. TSO28-1, is mainly determined by the organic carbon (SOC), total nitrogen (TN), and dissolved organic carbon (DOC). For the treatments without compost, SDP mainly followed the order of chemical fertilizers of N and P (NP) > chemical fertilizers of N and K (NK) > unfertilized (Nil) > chemical fertilizers of N, P, and K (NPK) > chemical fertilizers of P and K (PK), in which the variations had a close association with different specific microbial species. That is, relative to Nil, the enhanced SDP in NP and NK was coupled with the enrichment of Ideonella sp. NC3L-43b and R. gelatinosus, likely due to their higher NO3 contents, while the reduced SDP in NPK was linked to the depletions of R. gelatinosus and Azospira sp. NC3H-14, and that in PK to the depletion of R. gelatinosus and Azospirillum sp. TSO28-1, probably as a result of their lower N:P ratios. Microbial mechanisms for SDP differences varied with fertilization regimes, and R. gelatinosus can be regarded as a universal microbial indicator for SDP differences across the fertilization treatments. [ABSTRACT FROM AUTHOR]

Three dimensional soil textural structure in a township was conditionally simulated using a transition probability-based indicator geostatistical method based on 270 soil texture samples from 27 profiles. Additionally the distribution of soil profiles lacking clay interlayers (indicating high irrigation water and nutrient leaching risk) was analyzed using 500 realizations from the simulation. The results indicated that the simulation could predict the soil texture distribution with low uncertainties using the existing data, and the predicted soil map (0-10 cm) formed by the maximum probable soil textures also exhibited a good agreement with the legacy soil survey map. For water and nutrient leaching risk analysis, the areas lacking clay interlayer could be located; however, their distribution was still highly uncertain if based only on the existing sampling data. That means supplementary sampling in future is required for the risk assessment, and the existing study can help to optimise the sampling points and their distribution. Generally, the transition probability-based geostatistical simulation, as a stochastic conditional simulation method, exhibited its potential in soil texture spatial reproduction and related risk assessment. [ABSTRACT FROM AUTHOR]

Background: One important protein family that functions in nucleotide excision repair (NER) factors is the SNF2 family. A newly identified mouse ERCC6-like gene, Ercc6l (excision repair cross-complementing rodent repair deficiency, complementation group 6-like), has been shown to be another developmentally related member of the SNF2 family. Methodology/Principal Findings: In this study, Sika deer Ercc6l cDNA was first cloned and then sequenced. The full-length cDNA of the Sika deer Ercc6l gene is 4197 bp and contains a 3732 bp open reading frame that encodes a putative protein of 1243 amino acids. The similarity of Sika deer Ercc6l to Bos taurus Ercc6l is 94.05% at the amino acid sequence level. The similarity, however, is reduced to 68.42-82.21% when compared to Ercc6l orthologs in other mammals and to less than 50% compared to orthologs in Gallus gallus and Xenopus. Additionally, the expression of Ercc6l mRNA was investigated in the organs of fetal and adult Sika deer (FSD and ASD, respectively) by quantitative RT-PCR. The common expression level of Ercc6l mRNA in the heart, liver, spleen, lung, kidney, and stomach from six different developmental stages of 18 Sika deer were examined, though the expression levels in each organ varied among individual Sika deer. During development, there was a slight trend toward decreased Ercc61 mRNA expression. The highest Ercc6l expression levels were seen at 3 months old in every organ and showed the highest level of detection in the spleen of FSD. The lowest Ercc6l expression levels were seen at 3 years old. Conclusions/Significance: We are the first to successfully clone Sika deer Ercc6l mRNA. Ercc6l transcript is present in almost every organ. During Sika deer development, there is a slight trend toward decreased Ercc61 mRNA expression. It is possible that Ercc6l has other roles in embryonic development and in maintaining the growth of animals. [ABSTRACT FROM AUTHOR]

MiR-375 is a conserved noncoding RNA that is known to be involved in tumor cell proliferation, migration, and drug resistance. Previous studies have shown that miR-375 affects the epithelial–mesenchymal transition (EMT) of human tumor cells via some key transcription factors, such as Yes-associated protein 1 (YAP1), Specificity protein 1 (SP1) and signaling pathways (Wnt signaling pathway, nuclear factor κB (NF-κB) pathway and transforming growth factor β (TGF-β) signaling pathway) and is vital for the development of cancer. Additionally, recent studies have identified microRNA (miRNA) delivery system carriers for improved in vivo transportation of miR-375 to specific sites. Here, we discussed the role of miR-375 in different types of cancers, as well as molecular mechanisms, and analyzed the potential of miR-375 as a molecular biomarker and therapeutic target to improve the efficiency of clinical diagnosis of cancer. [ABSTRACT FROM AUTHOR]

Hydroxyurea (HU) is an FDA-approved drug used to treat a variety of diseases, especially malignancies, but is harmful to fertility. We used porcine oocytes as an experimental model to study the effect of HU during oocyte maturation. Exposure of cumulus-oocyte complexes (COCs) to 20 µM (P<0.01) and 50 µM (P<0.001) HU reduced oocyte maturation. Exposure to 20 µM HU induced approximately 1.5- and 2-fold increases in Caspase-3 (P<0.001) and P53 (P<0.01) gene expression levels in cumulus cells, respectively, increased Caspase-3 (P<0.01) and P53 (P<0.001) protein expression levels in metaphase II (MII) oocytes and increased the percentage of apoptotic cumulus cells (P<0.001). In addition, HU decreased the mitochondrial membrane potential (Δφm) (P<0.01 and P<0.001) and glutathione (GSH) levels (P<0.01 and P<0.001) of both cumulus cells and MII oocytes, while increasing their reactive oxygen species (ROS) levels (P<0.001). Following parthenogenetic activation of embryos derived from MII oocytes, exposure to 20 µMHU significantly reduced total blastocyst cell numbers (P<0.001) and increased apoptosis of blastocyst cells (P<0.001). Moreover, HU exposure reduced the rate of development of two-celled, four- to eight-celled, blastocyst, and hatching stages after parthenogenetic activation (P<0.05). Our findings indicate that exposure to 20 µM HU caused significant oxidative stress and apoptosis of MII oocytes during maturation, which affected their developmental ability. These results provide valuable information for safety assessments of HU. [ABSTRACT FROM AUTHOR]

Objective: An experiment was conducted to determine the effects of L-arginine (L-Arg) and N-carbamoylglutamic acid (NCG) on the growth, metabolism, immunity and community of cecal bacterial flora of weanling and young rabbits. Methods: Eighteen normal-grade male weanling Japanese White rabbits (JWR) were selected and randomly divided into 6 groups with or without L-Arg and NCG supplementation. The whole feeding process was divided into weanling stage (day 37 to 65) and young stage (day 66 to 85). The effects of L-Arg and NCG on the growth, metabolism, immunity and development of the ileum and jejunum were compared via nutrient metabolism experiments and histological assessment. The different communities of cecal bacterial flora affected by L-Arg and NCG were assessed using high-throughput sequencing technology and bioinformatics analysis. Results: The addition of L-Arg and NCG enhanced the growth of weanling and young rabbit by increasing the nitrogen metabolism, protein efficiency ratio, and biological value, as well as feed intake and daily weight gain. Both L-Arg and NCG increased the concentration of immunoglobulin A (IgA), IgM, and IgG. NCG was superior to L-Arg in promoting intestinal villus development by increasing villus height, villus height/crypt depth index, and reducing the crypt depth. The effects of L-Arg and NCG on the cecal bacterial flora were mainly concentrated in different genera, including Parabacteroides, Roseburia, dgA-11_gut_group, Alistipes, Bacteroides, and Ruminococcaceae_UCG-005. These bacteria function mainly in amino acid transport and metabolism, energy production and conversion, lipid transport and metabolism, recombination and repair, cell cycle control, cell division, and cell motility. Conclusion: L-Arg and NCG can promote the growth and immunity of weanling and young JWR, as well as effecting the jejunum and ileum villi. L-Arg and NCG have different effects in the promotion of nutrient utilization, relieving inflammation and enhancing adaptability through regulating microbial community. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the influence of negative pressure on boar semen quality during liquid preservation at 17°C. Semen samples from ten large white boars were collected and pooled, divided into four equal parts, and diluted with Modena containing 0.4% (w/v) of bovine serum albumin. The semen samples were placed in a closed container with valve, and a negative pressure was applied for 2-5 minutes using a vacuum pump with a barometer. The control group had no treatment, the P200 group was treated at 200 mbar, the P400 group at 400 mbar, and the P800 group at 800 mbar. During liquid preservation, sperm motility, total antioxidant capacity, and semen H2O2 content were analyzed every 24 h. The effective survival time of boar semen during preservation was evaluated. The results indicated that a suitable negative pressure decreased the effects on reactive oxygen species on boar sperm quality during liquid preservation compared with the control group. Among all the groups, the 400 mbar negative pressure group had the highest sperm motility, total antioxidant capacity, and the percentage of spermatozoa with high mitochondrial membrane potential. The P400 group also had semen H2O2 content than the other groups. A suitable negative pressure improves sperm quality by reducing oxidative stress and the respiratory metabolism of sperm, and the optimum negative pressure is 400 mbar. [ABSTRACT FROM AUTHOR]

In order to solve some problems of lower blastocyst rate of early embryos in vitro and poor quality of blastocyst, application of a microfluidic chip with mechanical stimuli (MS) to imitate microenvironment of fallopian tube, to investigate the effect of a microfluidic chip with mechanical stimuli on the early embryo development in mammalian. We designed and made a novel and simple system to apply MS similar to those generated inside the oviduct to cultured mammalian embryos by using poly(dimethylsiloxiane). Using this microfluidic chip embryo culture device to culture 2-cell stage mouse embryo from in vitro fertilization. There were large differences in development rates of > 4-cell stage, development rates of morula (63.1 ± 12.5% vs. 80.6 ± 17.9%) and blastocyst (58.6 ± 2.3% vs. 73.2 ± 2.8%) between control and microfluidic chip group (p < 0.05). meanwhile, there was large differences in cell numbers of inner cell mass in blastocyst between control and microfluidic chip group (p < 0.05). These results suggested that the culture device can significantly improve blastocyst development rate of embryo in vitro and the quality of the blastocyst in mice, this novel and simple system was feasible to generate and apply MS similar to those generated inside the oviduct to cultured mammalian embryos. [ABSTRACT FROM AUTHOR]

Heat stress dramatically decreases bull sperm quality and has recently received more attention due to the warmer global climate and more intensive production. However, no data exist regarding sperm quality or the related molecular mechanisms under heat stress. Recent studies showed that inducible heat shock proteins (HSPs) play an important role in the dairy heat stress regulation. In this article, to investigate the impacts of heat stress on sperm quality and the associated molecular mechanisms, sperm quality and enzyme activities concerning acrosome reaction were assessed in Simmental, Limousin and Yanbian bulls under heat stress. Subsequently, changes in heat shock protein expression profiles of Simmental bulls were observed, because we observed that sperm quality of these bulls was most sensitive to heat stress. Finally, the relationship between sperm quality and heat shock protein expression under heat stress was analyzed. The results show that summer heat stress decreased the sperm quality of the three bull breeds significantly. Moreover, different levels of heat stimulation induced various enzyme activity changes, among which the activity change in acrosomal enzyme was the most remarkable. Furthermore, the expression of heat shock proteins in the sperm was influenced by the imposed heat stress, among which the expression levels of HSP60 and HSP70 were increased while HSP90 decreased. In summary, our data show that heat stress seriously affects sperm quality and that HSP90 was most sensitive, although it should be noted that seasonal effects may confound these results. This change in heat shock protein expression may be the major factor that affected the sperm quality of the bulls. The findings may provide a new hypothesis for how heat stress impacts reproduction mechanistically. [ABSTRACT FROM AUTHOR]

Recent experimental results showed that the Tg of cured resin scarcely decreased and the impact strength of resins increased by over 50% when a tetrafunctional epoxy named N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl ether (TGDDE) was introduced to an appropriate flexible chain from a dimer fatty acid (DFA). In order to understand the reason for this phenomenon, the modification and the chemical structure of the prepolymer together with the curing reaction and the viscoelasticity of the cured resins were studied in detail in the present work. The results indicated that the modification would help the prepolymer improve its molecular mobility. As a result, the resins could be further cured, resulting in the cross-linking density increasing. This is because the curing efficiency was increased, but the tetrafunctional epoxy was not cured completely due to its large steric hindrance. Moreover, the flexibility of some parts of the networks was improved, which was beneficial for the toughness of the cured resins. Therefore, the toughness of the tetrafunctional resin was improved with little influence on the thermal properties when the epoxies were modified with an appropriate content of DFA. [ABSTRACT FROM AUTHOR]

Mathematical descriptions of classical particle size distribution (PSD) data are often used to estimate soil hydraulic properties. Laser diffraction methods (LDM) now provide more detailed PSD measurements, but deriving a function to characterize the entire range of particle sizes is a major challenge. The aim of this study was to compare the performance of eighteen PSD functions for fitting LDM data sets from a wide range of soil textures. These models include five lognormal models, five logistic models, four van Genuchten models, two Fredlund models, a logarithmic model, and an Andersson model. The fits were evaluated using Akaike’s information criterion (AIC), adjusted R2, and root-mean-square error (RMSE). The results indicated that the Fredlund models (FRED3 and FRED4) had the best performance for most of the soils studied, followed by one logistic growth function extension model (MLOG3) and three lognormal models (ONLG3, ORLG3, and SHCA3). The performance of most PSD models was better for soils with higher silt content and poorer for soils with higher clay and sand content. The FRED4 model best described the PSD of clay, silty clay, clay loam, silty clay loam, silty loam, loam, and sandy loam, whereas FRED3, MLOG3, ONLG3, ORLG3, and SHCA3 showed better performance for most soils studied. [ABSTRACT FROM AUTHOR]

Organic manure (OM) fertilization has a profound impact on agroecosystems. However, little is known about temporal responses and roles of the specific soil microbial guilds involved in the increases of soil fertility and crop yield triggered by OM fertilization. To unravel these interactions, a series of fresh and archived soil samples from a fertilization experiment started in 1989 in North China Plain (NCP) was systematically investigated. Molecular assays of contemporary fresh samples unravel that Bacillus asahii responded most distinctly to OM fertilization, while no shifts in microbial community structure were observed between chemical fertilizations and the control without fertilization; a series of archived soil samples from 1989 to 2009 reveal that the indigenous B. asahii took 2-4 years to become specifically dominant and its ratio fluctuated between 40% and 72% during 20 years. Culture-dependent assessments of isolated B. asahii strain further indicate that its rise subsequently played a key role in the increases of both crop yield and soil fertility, especially via accelerating carbon and phosphorus cycling. This insight deepens our understanding of how OM impacts agroecosystems through soil microbial processes, and highlights the possibility of using archived microbial information as a reference to develop an efficient and sustainable agricultural strategy. [ABSTRACT FROM AUTHOR]

A balanced fertilization can increase crop yields partly due to stimulated microbial activities and growths. In this study, we investigated arbuscular mycorrhizal fungi (AMF) in arable soils to determine the optimal practices for an effective fertilization. We used pyrosequencing-based approach to study AMF diversity, as well as their responses to different long-term (>20 years) fertilizations, including OM (organic manure) and mix chemical fertilizers of NP (nitrogen-phosphorus), NK (nitrogen-potassium), and NPK (nitrogen-phosphorus-potassium). Results revealed that 124?998 of 18S rRNA gene fragments were dominated by Glomeromycota with 59?611 sequences, generating 70 operational taxonomic units (OTUs), of which the three largest families were Glomeraceae, Gigasporaceae and Acaulosporaceae. In Control and NK plots, AMF diversity and richness significantly decreased under long-term P fertilizations, such as NP, NPK, and OM. Concomitantly, the AMF community structure shifted. Supported by canonical correspondence analysis, we hereby propose that long-term balanced fertilization, especially P fertilizer with additional N fertilizer, helps the build-up of soil nutrients. Consequently, some AMF community constituents are sacrificed, propelled by the self-regulation of plant-AMF-microbes system, resulting in an agro-ecosystem with a better sustainability. This knowledge would be valuable toward better understandings of AMF community in agro-ecosystem, and long-term ecosystem benefits of the baled fertilization. [ABSTRACT FROM AUTHOR]

Gonadotropin-regulated testicular RNA helicase (GRTH/DDX25), a testis-specific member of the DEAD-box family, is an essential post-transcriptional regulator of spermatogenesis. Failure of expression of Transition protein 2 (TP2) and Protamine 2 (Prm2) proteins (chromatin remodelers, essential for spermatid elongation and completion of spermatogenesis) with preservation of their mRNA expression was observed in GRTH-null mice (azoospermic due to failure of spermatids to elongate). These were identified as target genes for the testis-specific miR-469, which is increased in the GRTH-null mice. Further analysis demonstrated that miR-469 repressed TP2 and Prm2 protein expression at the translation level with minor effect on mRNA degradation, through binding to the coding regions of TP2 and Prm2 mRNAs. The corresponding primary-microRNAs and the expression levels of Drosha and DGCR8 (both mRNA and protein) were increased significantly in the GRTH-null mice. miR-469 silencing of TP2 and Prm2 mRNA in pachytene spermatocytes and round spermatids is essential for their timely translation at later times of spermiogenesis, which is critical to attain mature sperm. Collectively, these studies indicate that GRTH, a multifunctional RNA helicase, acts as a negative regulator of miRNA-469 biogenesis and consequently their function during spermatogenesis. [ABSTRACT FROM AUTHOR]

Background—We previously demonstrated that macrophage low-density lipoprotein receptor (LDLR)-related protein 1 (LRP1) deficiency increases atherosclerosis despite antiatherogenic changes including decreased uptake of remnants and increased secretion of apolipoprotein E (apoE). Thus, our objective was to determine whether the atheroprotective effects of LRP1 require interaction with apoE, one of its ligands with multiple beneficial effects. Methods and Results—We examined atherosclerosis development in mice with specific deletion of macrophage LRP1 (apoE-/- MΦLRP1-/-) and in LDLR-/- mice reconstituted with apoE-/- MΦLRP1-/- bone marrow. The combined absence of apoE and LRP1 promoted atherogenesis more than did macrophage apoE deletion alone in both apoE-producing LDLR-/- mice (+88%) and apoE-/- mice (+ 163%). The lesions of both mouse models with apoE-/- LRP1-/- macrophages had increased macrophage content. In vitro, apoE and LRP1 additively inhibit macrophage apoptosis. Furthermore, there was excessive accumulation of apoptotic cells in lesions of both LDLR-/- mice (+ 110%) and apoE-/- MΦLRP1-/- mice (+252%). The apoptotic cell accumulation was partially due to decreased efferocytosis as the ratio of free to cell-associated apoptotic nuclei was 3.5-fold higher in lesions of apoE-/- MΦLRP1-/- versus apoE-/- mice. Lesion necrosis was also increased (6 fold) in apoE-/- MΦLRP1-/- versus apoE-/- mice. Compared with apoE-/- mice, the spleens of apoE-/- MΦLRP1-/- mice contained 1.6-and 2.4-fold more total and Ly6-Chigh monocytes. Finally, there were 3.6- and 2.4-fold increases in Ly6-Chigh and CC-chemokine receptor 2-positive cells in lesions of apoE-/- MΦLRP1-/- versus apoE-/- mice, suggesting that accumulation of apoptotic cells enhances lesion development and macrophage content by promoting the recruitment of inflammatory monocytes. Conclusion—Low-density lipoprotein receptor protein I exerts antiatherogenic effects via pathways independent of apoE involving macrophage apoptosis and monocyte recruitment. [ABSTRACT FROM AUTHOR]

The P efficiency, crop yield, and response of wheat to arbuscular mycorrhizal fungus (AMF) Glomus caledonium were tested in an experimental field with long-term (19 years) fertilizer management. The experiment included five fertilizer treatments: organic amendment (OA), half organic amendment plus half mineral fertilizer (1/2 OM), mineral fertilizer NPK, mineral fertilizer NK, and the control (without fertilization). AMF inoculation responsiveness (MIR) of wheat plants at acquiring P were estimated by comparing plants grown in unsterilized soil inoculated with G. caledonium and in untreated soil containing indigenous AMF. Without AMF inoculation, higher crop yields but lower colonization rates were observed in the NPK and two OA-inputted treatments, and NPK had significantly ( P < 0.05) lower impacts on organic C and available P in soils and thereby P acquisition of wheat plants compared with OA and 1/2 OM. G. caledonium inoculation significantly ( P < 0.05) increased colonization rates with the NPK and two P-deficient treatments but significantly ( P < 0.05) increased vegetative biomass, crop yield, and P acquisition of wheat as well as soil alkaline phosphatase (ALP) activity, only with the NPK treatment. This gave an MIR of ca. 45% on total P acquisition of wheat plants. There were no other remarkable MIRs. It suggested that the MIR is determined by soil available P status, and rational combination of AMF with chemical NPK fertilizer can compensate for organic amendments by improving P-acquisition efficiency in arable soils. [ABSTRACT FROM AUTHOR]

The effects of mineral fertilizer (NPK) and organic manure on the community structure of soil ammonia-oxidizing bacteria (AOB) was investigated in a long-term (16-year) fertilizer experiment. The experiment included seven treatments: organic manure, half organic manure N plus half fertilizer N, fertilizer NPK, fertilizer NP, fertilizer NK, fertilizer PK, and the control (without fertilization). N fertilization greatly increased soil nitrification potential, and mineral N fertilizer had a greater impact than organic manure, while N deficiency treatment (PK) had no significant effect. AOB community structure was analyzed by PCR-denaturing gradient gel electrophoresis (PCR-DGGE) of the amoA gene, which encodes the α subunit of ammonia monooxygenase. DGGE profiles showed that the AOB community was more diverse in N-fertilized treatments than in the PK-fertilized treatment or the control, while one dominant band observed in the control could not be detected in any of the fertilized treatments. Phylogenetic analysis showed that the DGGE bands derived from N-fertilized treatments belonged to Nitrosospira cluster 3, indicating that N fertilization resulted in the dominance of Nitrosospira cluster 3 in soil. These results demonstrate that long-term application of N fertilizers could result in increased soil nitrification potential and the AOB community shifts in soil. Our results also showed the different effects of mineral fertilizer N versus organic manure N; the effects of P and K on the soil AOB community; and the importance of balanced fertilization with N, P, and K in promoting nitrification functions in arable soils. [ABSTRACT FROM AUTHOR]

A pot experiment was conducted in a glasshouse to clarify and quantify the effect of plant part, water regime, growth period, and cultivar on carbon isotope discrimination (CID), and to analyze the relationship between CID, stomatal behavior and water-use efficiency (WUE). The experiment was comprised of two upland rice (Oryza sativa L.) cultivars and three water regimes (100, 70, and 40% of saturation moisture) in a completely randomized design. Plants were harvested at tillering, flowering, and maturity. No significant cultivar differences in above-ground dry matter-based WUE (WUEA) and total dry matter-based WUE (WUET) were observed. WUEA (and WUET) increased with water stress up to tillering, but decreased with water stress after tillering. Significant cultivar differences in CID in all the analyzed plant parts were observed at all harvest times. Reduction in CID with water stress was greatest at tillering, and the effect was less pronounced at flowering and at maturity. At each harvest, the effect was most pronounced in newly developed plant parts. Root and grain tended to have the lowest CID values, and stem the highest, at all harvest times. A negative relationship was observed between CID measured at tillering and WUEA (and WUET) measured over the period from seedling to tillering, whereas a reverse relationship was obtained between CID measured at flowering and WUEA (and WUET) measured over the period from tillering to flowering, and an unclear relationship between CID measured at maturity and WUEA (and WUET) measured over the period from flowering to maturity. The ratio of the intercellular and atmospheric concentration of CO2 (Ci/Ca) were closely associated with CID throughout the water regimes when one cultivar was considered, however, cultivar differences in CID were not related to variations in Ci/Ca. The results indicate that significant cultivar difference existed in CID in all the analyzed plant parts at all harvest times, while corresponding difference in WUEA (and WUET) between the cultivars was not necessarily consistent. Abbreviations: WUE – water-use efficiency; WUEi – instantaneous WUE (or leaf transpiration efficiency); ADM – above-ground dry matter; TDM – total dry matter; WUEA – ADM-based WUE; WUET – TDM-based WUE}; CID – carbon isotope discrimination; NL – the newest leaves; FEL – recently fully expanded leaves; FL – flag leaves; P – photosynthesis rate; g – leaf stomatal conductance to water vapor; Ci – intercellular CO2 concentration; Ca – atmospheric CO2 concentration; T – transpiration rate; gs – total conductance of CO2 [ABSTRACT FROM AUTHOR]

[Objective] This study aimed to clone and express formyltransferase (Wbkc) gene from Brucella abortus in E. coli, purify the expressed protein and analyze its immunogenicity. [Method] A gene encoding 27-35 ku formyltransferase (Wbkc) was amplified from the genomic DNA of Brucella abortus by PCR. The amplified fragments were digested with BamH I and Sal I, and inserted into pET28a vector. The constructed recombinant plasmid pET 28 a-Wbkc was transformed into E. coli BL21 and was induced to express the fusion protein. Subsequently, the protein was purified by histidine-binding resin column chromatography, and the immunogenicity was detected by Western blot assay. The recombinant plasmid was identified by colony PCR, double digestion and sequencing analysis. [Result] Wbkc was successfully cloned and expressed in E. coli. A specific protein band of 29 ku was detected by SDS-PAGE. Western blot showed specific im-munoreactivity of the purified fusion protein. [Conclusion] This study provided a solid foundation for further investigating diagnostic proteins for brucellosis and developing Brucella gene-deletion vaccines. [ABSTRACT FROM AUTHOR]