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Gas-water relative permeability was tested in the full diameter cores of three types of reservoirs (matrix pore, fracture and solution pore) in Gaoshiti-Moxi block under high pressure and temperature to analyze features of their gas-water relative permeability curves and gas well inflow dynamics. The standard plates of gas-water two-phase relative permeability curves of these types reservoirs were formed after normalization of experimental data. Based on the seepage characteristics of fractured reservoirs, the calibration methods of gas-water two-phase relative permeability curves were proposed and the corresponding plates were corrected. The gas-water two-phase IPR (inflow performance relationship) curves in different type reservoirs were calculated using the standard plates and validated by the actual performances of gas wells respectively. The results show that: water saturations at gas-water relative permeability equal points of studied reservoirs are over 70%, indicating strong hydrophilic; the dissolved cave type has the biggest gas-water infiltration interval and efficiency of water displacement by gas, followed by the matrix pore type and then fractured type; and the fractured type has the highest the permeability recovery degree, followed by the dissolved cave type and then matrix pore type. The calibrated gas-water two-phase relative permeability curves of fractured carbonate reservoirs can better reflect the gas-water two-phase seepage law of actual gas reservoirs and the standard plates can be used in the engineering calculation of various gas reservoirs. The characteristics of calculated IPR curves are consistent with the performance of actual producing wells, and are adaptable to guide production proration and performance analysis of gas wells. Key words: carbonate reservoir, simultaneous production of gas and water, gas-water relative permeability curves, IPR curve, gas well

Abstract Elevated triglyceride (TG) levels are well-correlated with the risk for cardiovascular disease (CVD). Apolipoprotein CIII (ApoC-III) is a key regulator of plasma TG levels through regulation of lipolysis and lipid synthesis. To identify novel regulators of TG levels, we carried out a high throughput screen (HTS) using an ApoC-III homogenous time resolved fluorescence (HTRF) assay. We identified several retinoic acid receptor (RAR) agonists that reduced secreted ApoC-III levels in human hepatic cell lines. The RARα specific agonist AM580 inhibited secreted ApoC-III by >80% in Hep3B cells with an EC50 ~2.9 nM. In high-fat diet induced fatty-liver mice, AM580 reduced ApoC-III levels in liver as well as in plasma (~60%). In addition, AM580 treatment effectively reduced body weight, hepatic and plasma TG, and total cholesterol (TC) levels. Mechanistically, AM580 suppresses ApoC-III synthesis by downregulation of HNF4α and upregulation of SHP1 expression. Collectively, these studies suggest that an RARα specific agonist may afford a new strategy for lipid-lowering and CVD risk reduction.

Abstract China experiences some of the highest rates of anthropogenic nitrogen deposition globally, with further increases projected. Understanding of soil feedbacks to the combined anthropogenic influences of climate change and nitrogen deposition in these systems is critical to improve predictive abilities for future climate scenarios. Here we used a Michaelis-Menten substrate-based kinetics framework to explore how soil CO2 production (Rsoil) responds to changes in temperature and available soil nitrogen (N) by combining field experiments with laboratory manipulations from sites experiencing elevated rates of anthropogenic N deposition but varying in soil N availabiltiy. The temperature sensitivity of Rsoil was strongly influenced by labile C additions. Furthermore, estimation of the temperature response of the Michaelis-Menten parameters supports the use of substrate-based kinetics in modeling efforts. Results from both field and laboratory experiments demonstrated a general decrease in Rsoil with increasing soil available N that was variably dependent on carbon (C) availability. Both the field and the laboratory measurements demonstrated a consistent decrease in the Michaelis-Menten parameter kM with increasing soil available N, indicating an increase in the efficiency of soil C decomposition with increasing N. Furthermore, these results provide evidence of interactions between N deposition and temperature sensitivity, which could influence C storage under combined anthropogenic global change drivers.

Soil contains a large amount of organic matter, which constitutes the largest terrestrial carbon pool. Heterotrophic or microbial respiration (Rh) that results from microbial decomposition of soil organic carbon (SOC) constitutes a substantial proportion of soil C efflux. Whether soil microbial biomass is of primary importance in controlling Rh remains under debate, and the question of whether the microbial biomass-decomposition relationship changes with warming and nitrogen (N) deposition has rarely been assessed. We conducted an incubation experiment to test the relationship between Rh and the size of soil microbial communities in two layers of soil collected from a natural subtropical forest and to examine whether the relationship was affected by changes in temperature and by added N in different forms. The results showed that regardless of the added N species, the N load did not significantly affect Rh or the size of the soil microbial communities. These results could be due to a long-term N-rich soil condition that acclimates soil microbial communities to resist N inputs into the studied forest; however, warming may significantly stimulate SOC decomposition, reducing soil microbial biomass under high temperatures. A significant linear soil microbial biomass-decomposition relationship was observed in our study, with the coefficients of determination ranging from 54 to 70%. Temperature rather than N additions significantly modified the linear relationship between soil microbial biomass and respiration. These results suggest that warming could impose a more substantial impact than N addition on the relationship between soil microbial biomass and SOC decomposition.

Seasonality, an exogenous driver, motivates the biological and ecological temporal dynamics of animal and plant communities. Underexplored microbial temporal endogenous dynamics hinders the prediction of microbial response to climate change. To elucidate temporal dynamics of microbial communities, temporal turnover rates, phylogenetic relatedness, and species interactions were integrated to compare those of a series of forest ecosystems along latitudinal gradients. The seasonal turnover rhythm of microbial communities, estimated by the slope (w value) of similarity-time decay relationship, was spatially structured across the latitudinal gradient, which may be caused by a mixture of both diurnal temperature variation and seasonal patterns of plants. Statistical analyses revealed that diurnal temperature variation instead of average temperature imposed a positive and considerable effect alone and also jointly with plants. Due to higher diurnal temperature variation with more climatic niches, microbial communities might evolutionarily adapt into more dispersed phylogenetic assembly based on the standardized effect size of MNTD metric, and ecologically form higher community resistance and resiliency with stronger network interactions among species. Archaea and the bacterial groups of Chloroflexi, Alphaproteobacteria, and Deltaproteobacteria were sensitive to diurnal temperature variation with greater turnover rates at higher latitudes, indicating that greater diurnal temperature fluctuation imposes stronger selective pressure on thermal specialists, because bacteria and archaea, single-celled organisms, have extreme short generation period compared to animal and plant. Our findings thus illustrate that the dynamics of microbial community and species interactions are crucial to assess ecosystem stability to climate variations in an increased climatic variability era.

Numerous reforestation projects have been conducted to improve soil fertility in degraded forests, often causing alterations to the soil microbial communities. However, it remains unclear whether microbial functional groups are affected and how these groups correlate with an increase in the nutrient contents during reforestation. We investigated the abundance and composition of free-living nitrogen-fixing microorganisms (diazotrophs) by quantifying and sequencing the marker gene nifH in bulk soils from five reforestation approaches, including legumes and non-legumes, in subtropical China. The relationships between diazotrophic community attributes and soil nitrogen (N) content [NO3−, NH4+, and microbial biomass N (MBN)] were examined under various approaches. Abundance of diazotrophs was highest in the native tree plantation (Schima spp. and Michelia macclurei) and Acacia mangium monoculture (AM), and lowest in the Pinus massoniana monoculture. The diazotrophic abundance correlated positively with soil organic matter and water content while there was a negative correlation to pH. The composition of diazotrophic community differed significantly among the five reforestation approaches examined and was closely correlated with variations in soil pH, NH4+ and water content. Diazotrophic community composition was closely related to soil NH4+ content, whereas abundance was not. The AM contained higher NH4+, NO3− and MBN contents than the other reforestation approaches, which may be associated with the indicator species of diazotrophs (Actinobacteria, Proteobacteria, and Firmicutes). However, there were more indicator species of Proteobacteria in the mixed Acacia plantation (Acacia mangium and Acacia crassicarpa) than in AM, which might have contributed to the remarkedly lower N content compared to AM. Overall, the soil N content under reforestation appeared to be more related to the composition of diazotroph community than to the abundance of diazotrophs.

The movable water saturation of tight sandstone reservoirs is an important parameter in characterizing water production capacity, and there is a great need to understand the relationship between movable water saturation and water production characteristics. However, movable water behavior in this context remains unclear. In this study, four groups of tight sandstone cores from the Sulige gas field are measured to understand the movable water saturation characteristics. Then, the effects such as reservoir micropore throat, clay mineral and physical properties on movable water saturation are analyzed, and the movable water saturation and water production characteristics are discussed. The results show that higher movable water saturation will result in a greater amount of water in the gas drive. There is a critical pressure difference of the gas drive, and a large amount of movable water will flow out. Movable water saturation is independent of the porosity, permeability and initial water saturation, while it is closely related to the reservoir micropore throat and clay mineral content. Movable water is mainly distributed in the medium and large pores; the larger the proportion of such pores, the higher the degree of movable water saturation. A lower mineral content will lead to higher movable water saturation in tight sandstone gas reservoirs. These results provide clues for identifying gas–water bearing reservoirs and evaluating and predicting the water production characteristics in gas wells in tight sandstone gas reservoirs.

Owing to their pleiotropic metabolic benefits, glucagon-like peptide-1 receptor (GLP-1R) agonists have been successfully utilized for treating metabolic diseases, such as type 2 diabetes and obesity. As part of our efforts in developing long-acting peptide therapeutics, we have previously reported a peptide engineering strategy that combines peptide side chain stapling with covalent integration of a serum protein-binding motif in a single step. Herein, we have used this strategy to develop a second generation extendin-4 analog rigidified with a symmetrical staple, which exhibits an excellent in vivo efficacy in an animal model of diabetes and obesity. To simplify the scale-up manufacturing of the lead GLP-1R agonist, a semisynthesis protocol was successfully developed, which involves recombinant expression of the linear peptide followed by attachment of a polyethylene glycol (PEG)-fatty acid staple in a subsequent chemical reaction step.

Airborne bacteria play important roles in air pollution, human health and biogeochemical cycles. However, their spatial variation and determinant factors in forest environments are poorly understood. In this study, we selected five forest types in the Liuxihe National Park, South China, to analyze how near-surface bacterial community structure is related to the forest community structure and soil physicochemical properties. The results indicated that the dominant communities were mainly constituted by seven bacterial genera of the phyla Proteobacteria (49.7%–55.4%) and Firmicutes (44.2%–49.8%), including Exiguobacterium (42.0%–46.4%), Citrobacter (20.7%–25.8%), Acinetobacter (20.1%–22.1%), and Pseudomonas (7.8%–8.9%) etc. However, differences in the composition and diversity of the airborne bacterial communities were evident among the five forests, especially with respect to the dominant taxa. The relative abundance of Enterococcus and Bacillus in coniferous and broad-leaved mixed forest (MF), broad-leaved mixed forest (BF), and pure Cunninghamia lanceolata forest (CL) was significantly higher than that of the other forests, while the relative abundance of Citrobacter was significantly lower. The relative abundance of Citrobacter, Acinetobacter, and Pseudomonas in Proteobacteria were significantly negatively correlated with plant diversity and acid phosphatase activity but positively correlated with soil pH and soil available potassium. Contrastingly, the correlation between the relative abundance of most genera of Firmicutes and the above environmental factors is just the opposite of that for Proteobacteria. We provide direct evidence that native plant communities in the middle stage of succession, compared to planted forests and forest open space, generally had higher airborne bacterial diversity. Airborne bacterial diversity showed a significantly positive correlation with plant diversity (p < 0.05). Over all, soil pH, soil available potassium, and soil available phosphorus contributed to a high rate of the diversity of the airborne bacterial community in near-surface, followed by the plant diversity of the arbor layer and the near-surface air temperature. These results extended our understanding of the ecological patterns of airborne bacteria in forest ecosystems.

Synchrony of energy and nitrogen release in rumen has been proposed to maximize ruminal microbial fermentation. However, the information regarding bacterial community composition and its metabolism under a higher or lower degree of synchronization is limited. In our study, a 0 to 6 h post-feeding infusion (first half infusion, FHI), 6 to 12 h post-feeding infusion (second half infusion, SHI), and 0 to 12 h post-feeding infusion (continuous infusion, CI) of maltodextrin were used to simulate varying degrees of synchronization of energy and nitrogen release in a rumen simulation system. In addition, the bacterial community, metabolite, enzyme activity, and microbial protein synthesis (MPS) were evaluated. Compared with the FHI and CI, the relative abundance of Fibrobacter, Ruminobacter, BF311, and CF231 decreased in the SHI, but that of Klebsiella and Succinivibrio increased in the SHI. The NH3-N and branched-chain volatile fatty acids were significantly higher, but propionate content and activities of glutamate dehydrogenase (GDH) and alanine dehydrogenase were significantly lower in the SHI than those in the FHI and CI. The SHI had lower MPS and less efficiency of MPS than the FHI and CI, which indicated that the SHI had a lower degree of synchronization. Correlation analysis showed that MPS was positively related to GDH activity and relative abundance of Fibrobacter but negatively related to NH3-N and relative abundance of Klebsiella. Therefore, a higher degree of synchronization of energy and nitrogen release increased MPS partly via influencing the bacterial community, metabolism, and enzyme activities of ammonia assimilation in the in vitro fermenters.

Prerequisite for selection of appropriate tree species in afforestation programs is to understand their water use strategy. Acacia mangium Willd., Schima wallichii Choisy, and Cunninghamia lanceolata (Lamb.) Hook are the three main vegetation restoration pioneer species in southern China, but no comparative research on the water use strategy of these three tree species have been reported. Our objective was to gain a detailed understanding of how photosynthetically active radiation (PAR), vapor pressure deficit (VPD), and soil water content (SWC) at different soil depths control the sap flux density (Js) in the dry and wet seasons. We measured the Js of these three tree species by using the thermal dissipation method in low subtropical China. We found that both S. wallichii and C. lanceolata differed clearly in their stomatal behavior from one season to another, while A. mangium did not. The canopy conductance per sapwood area of S. wallichii and C. lanceolata was very sensitive to VPD in the dry season, but not in the wet season. The Js of A. mangium was negatively correlated to SWC in all soil layers and during both seasons, while the other two species were not sensitive to SWC in the deeper layers and only positively correlated to SWC in dry season. Our results demonstrate that the three species have distinct water use strategies and may therefore respond differently to changing climate.

Reservoir quality and productivity of fractured gas reservoirs depend heavily on the degree of fracture development. The fracture evaluation of such reservoir media is the key to quantify reservoir characterization for the purposes such as well drilling and completion as well as development and simulation of fractured gas reservoirs. In this study, a pore-fracture network model was constructed to understand the effects of fracture on permeability in the reservoir media. The microstructure parameters of fractures including fracture length, fracture density, fracture number, and fracture radius were analyzed. Then two modes and effects of matrix and fracture network control were discussed. The results indicate that the network permeability in the fractured reservoir media will increase linearly with fracture length, fracture density, fracture number, and fracture radius. When the fracture radius exceeds 80 µm, the fracture radius has a little effect on network permeability. Within the fracture density less than 0.55, it belongs to the matrix control mode, while the fracture network control mode is dominant in the fracture density exceeding 0.55. The network permeability in the matrix and fracture network control modes is affected by fracture density and the ratio of fracture radius to pore radius. There is a great change in the critical density for the matrix network control compared with the fracture network control. This work can provide a better understanding of the relationship between matrix and fractures, and the effects of fracture on permeability so as to evaluate the fluid flow in the fractured reservoir media.

Drought has had considerable effects on the ecological functions and processes of terrestrial ecosystems. However, little is known about the impacts of seasonal drought on the water use efficiency (WUE) and plant nitrogen (N) availability of dominant trees under field conditions. In this study, a field throughfall exclusion experiment simulating short-term drought (∼67% throughfall exclusion during the dry season from October to March) and prolonged drought (∼67% throughfall exclusion prolonging the dry season from October to May) was designed to understand the effects of seasonal drought on two dominant tree species (Michelia macclurei and Schima superba) in subtropical forest. The C and N content and isotopes in the deeper but not the surface soils in the forest were significantly affected by the seasonal drought. Neither the short-term nor the prolonged drought significantly altered δ13C values in the leaves and fine roots of the two species, but the short-term drought caused significant changes in δ15N values in the leaves and fine roots of S. superba. The WUE of the two dominant trees, indicated by the leaf δ13C values, was not significantly changed by the short-term and the prolonged drought. However, the N availability of S. superba, indicated by the δ15N values, was significantly altered by the seasonal short-term drought. Long-term influence of seasonal drought on the forest hydrological and N cycling and the potential shifts of species dominance induced by the changed N availability in subtropical forests should be assessed in the future research. Keywords: Nitrogen availability, Seasonal drought, Subtropical forest, Throughfall exclusion, Water use efficiency

Shales in the Well district of Yu 106 of the Shanxi Formation in the Eastern Ordos Basin is deposited in the swamp between delta plains, distributary river channels, natural levee, the far end of crevasse splay, and depression environments. According to organic geochemistry, reservoir physical property, gas bearing capacity, lithology experimental analysis, combined with the data of drilling, logging, testing and sedimentary facies, the reservoir conditions of shale gas and the distribution of an advantageous area in Shanxi Formation have been conducted. The results show that the total organic carbon content of the Shanxi Formation is relatively high, with an average content value of 5.28% in the segment 2 and 3.02% in segment 1, and the organic matter is mainly kerogen type II2 and III. The maturity of organic matter is high with 1.89% as the average value of R o which indicates the superior condition for gas generation of this reservoir. The porosity of shales is 1.7% on average, and the average permeability is 0.0415 × 10 −3 µm 2 . The cumulative thickness is relatively large, with an average of 75 m. Brittle mineral and clay content in shales are 49.9% and 50.1%, respectively, but the burial depth of shale is less than 3000 m. The testing gas content is relatively high (0.64 × 10 4 m 3 /d), which shows a great potential in commercial development. The total organic carbon of the segment 2 is higher than that of the segment 1, and it is also better than segment 1 in terms of gas content. Based on the thickness of shale and the distribution of sedimentary facies, it is predicted that the advantageous area of shale gas in the segment 2 is distributed in a striped zone along the northeast and the northsouth direction, which is controlled by the swamp microfacies between distributary river channels.

Climate changes, including chronic changes in precipitation amounts, will influence plant physiology and growth. However, such precipitation effects on switchgrass, a major bioenergy crop, have not been well investigated. We conducted a two-year precipitation simulation experiment using large pots (95 L) in an environmentally controlled greenhouse in Nashville, TN. Five precipitation treatments (ambient precipitation, and -50%, -33%, +33%, and +50% of ambient) were applied in a randomized complete block design with lowland "Alamo" switchgrass plants one year after they were established from tillers. The growing season progression of leaf physiology, tiller number, height, and aboveground biomass were determined each growing season. Precipitation treatments significantly affected leaf physiology, growth, and aboveground biomass. The photosynthetic rates in the wet (+50% and +33%) treatments were significantly enhanced by 15.9% and 8.1%, respectively, than the ambient treatment. Both leaf biomass and plant height were largely increased, resulting in dramatically increases in aboveground biomass by 56.5% and 49.6% in the +50% and +33% treatments, respectively. Compared to the ambient treatment, the drought (-33% and -50%) treatments did not influence leaf physiology, but the -50% treatment significantly reduced leaf biomass by 37.8%, plant height by 16.3%, and aboveground biomass by 38.9%. This study demonstrated that while switchgrass in general is a drought tolerant grass, severe drought significantly reduces Alamo's growth and biomass, and that high precipitation stimulates its photosynthesis and growth.

Atmospheric nitrogen (N) deposition is changing in both load quantity and chemical composition. The load effects have been studied extensively, whereas the composition effects remain poorly understood. We conducted a microcosm experiment to study how N chemistry affected the soil microbial community composition characterized by phospholipid fatty acids (PLFAs) and activity indicated by microbial CO2 release. Surface and subsurface soils collected from an old-growth subtropical forest were supplemented with three N-containing materials (ammonium, nitrate, and urea) at the current regional deposition load (50 kg ha-1 yr-1) and incubated at three temperatures (10, 20, and 30°C) to detect the interactive effects of N deposition and temperature. The results showed that the additions of N, regardless of form, did not alter the microbial PLFAs at any of the three temperatures. However, the addition of urea significantly stimulated soil CO2 release in the early incubation stage. Compared with the control, N addition consistently reduced the temperature dependency of microbial respiration, implying that N deposition could potentially weaken the positive feedback of the warming-stimulated soil CO2 release to the atmosphere. The consistent N effects for the surface and subsurface soils suggest that the effects of N on soil microbial communities may be independent of soil chemical contents and stoichiometry.

Seasonal precipitation changes are increasingly severe in subtropical areas. However, the responses of soil nitrogen (N) cycle and its associated functional microorganisms to such precipitation changes remain unclear. In this study, two projected precipitation patterns were manipulated: intensifying the dry-season drought (DD) and extending the dry-season duration (ED) but increasing the wet-season storms following the DD and ED treatment period. The effects of these two contrasting precipitation patterns on soil net N transformation rates and functional gene abundances were quantitatively assessed through a resistance index. Results showed that the resistance index of functional microbial abundance (-0.03 ± 0.08) was much lower than that of the net N transformation rate (0.55 ± 0.02) throughout the experiment, indicating that microbial abundance was more responsive to precipitation changes compared with the N transformation rate. Spring drought under the ED treatment significantly increased the abundances of both nitrifying (amoA) and denitrifying genes (nirK, nirS, and nosZ), while changes in these gene abundances overlapped largely with control treatment during droughts in the dry season. Interestingly, the resistance index of the ammonia-oxidizing archaea (AOA) amoA abundance was significantly higher than that of the denitrifying gene abundances, suggesting that AOA were more resistant to the precipitation changes. This was attributed to the stronger environmental adaptability and higher resource utilization efficiency of the AOA community, as indicated by the lack of correlations between AOA gene abundance and environmental factors [i.e., soil water content, ammonium (NH4+) and dissolved organic carbon concentrations] during the experiment.

It is well-known that drought has considerable effects on plant traits from leaf to ecosystem scales; however, little is known about the relative contributions of various traits within or between tree species in determining the plant’s sensitivity or the tolerance to drought under field conditions. We conducted a field throughfall exclusion experiment to simulate short-term drought (∼67% throughfall exclusion during the dry season from October to March) and prolonged drought (∼67% throughfall exclusion prolonging the dry season from October to May) and to understand the effects of drought on two dominant tree species (Michelia macclurei and Schima superba) in subtropical forests of southern China. The morphological, physiological, and nutritional responses of the two species to the two types of drought were determined. There were significantly different morphological (leaf max length, max width, leaf mass per area), physiological (leaf proline) and nutritional (P, S, N, K, Ca, Mg) responses by M. macclurei and S. superba to prolonged drought. Comparison between the drought treatments for each species indicated that the trees responded species–specifically to the short-term and prolonged drought, with S. superba exhibiting larger plasticity and higher adaption than M. macclurei. M. macclurei responded more sensitively to prolonged drought in terms of morphology, proline content, and nutritional traits and to short-term drought with regard to soluble sugars content. The differential species-specific responses to drought will allow us to estimate the changes in dominant trees in subtropical forests of China that have experienced a decade’s worth of annual seasonal drought.

Plant attributes have direct and indirect effects on soil microbes via plant inputs and plant-mediated soil changes. However, whether plant taxonomic and functional diversities can explain the soil microbial diversity of restored forest ecosystems remains elusive. Here, we tested the linkage between plant attributes and soil microbial communities in four restored forests (Acacia species, Eucalyptus species, mixed coniferous species, mixed native species). The trait-based approaches were applied for plant properties and high-throughput Illumina sequencing was applied for fungal and bacterial diversity. The total number of soil microbial operational taxonomic units (OTUs) varied among the four forests. The highest richness of fungal OTUs was found in the Acacia forest. However, bacterial OTUs were highest in the Eucalyptus forest. Species richness was positively and significantly related to fungal and bacterial richness. Plant taxonomic diversity (species richness and species diversity) explained more of the soil microbial diversity than the functional diversity and soil properties. Prediction of fungal richness was better than that of bacterial richness. In addition, root traits explained more variation than the leaf traits. Overall, plant taxonomic diversity played a more important role than plant functional diversity and soil properties in shaping the soil microbial diversity of the four forests.

Acacia mangium (AM) and Pinus massoniana (PM) are widely planted in tropical regions, whereas their effects on soil microbial communities remain unclear. We did a comprehensive investigation of soil denitrifying bacterial communities in AM and PM monoculture plantations in Southern China based on the high throughput sequencing data of their functional genes: nirK, nirS, and nosZ. The average abundance of nosZ (1.3 × 107) was significantly higher than nirS (5.6 × 106) and nirK (4.9 × 105). Shannon estimator revealed a markedly higher α-diversity of nirS and nosZ communities in PM than in AM plantations. The AM and PM plantations were dominated by different nirS and nosZ taxa belonging to proteobacteria, actinobacteria, thermoleophilia, chloroflexia, and acidobacteria, while the dominant nirK taxa were mainly categorized into proteobacteria in both types of plantations. The structure of nirS and nosZ communities shifted substantially from AM to PM plantations with changes in soil moisture, NH4+, and microbial biomass nitrogen content. The species co-occurrence network of nirK community was better organized in a more modular manner compared to nirS and nosZ communities, and the network keystone species mostly occurred in PM plantations. These results indicated a highly species corporation of nirK community in response to environmental changes, especially in PM plantations. AM and PM plantations can form different soil denitrifying microbial communities via altering soil physicochemical properties, which may further affect soil N transformations.

Water invasion in carbonate gas reservoirs often results in excessive water production, which limits the economic life of gas wells. This is influenced by reservoir properties and production parameters, such as aquifer, fracture, permeability and production rate. In this study, seven full diameter core samples with dissolved pores and fractures were designed and an experimental system of water invasion in gas reservoirs with edge and bottom aquifers was established to simulate the process of water invasion. Then the effects of the related reservoir properties and production parameters were investigated. The results show that the edge and bottom aquifers supply the energy for gas reservoirs with dissolved pores, which delays the decline of bottom-hole pressure. The high water aquifer defers the decline of water invasion in the early stage while the big gas production rate accelerates water influx in gas reservoirs. The existence of fractures increases the discharge area of gas reservoirs and the small water influx can result in a substantial decline in recovery factor. With the increase of permeability, gas production rate has less influence on recovery factor. These results can provide insights into a better understanding of water invasion and the effects of reservoir properties and production parameters so as to optimize the production in carbonate gas reservoirs.

The gas transport in shale nanopores is always one of the major concerns in terms of the development of shale gas reservoirs. In this study, the gas flow regimes in shale nanopores were classified and analyzed according to Knudsen number. Then the gas flow model considering Darcy flow, slip flow, transition flow, molecular free flow and adsorption effect was proposed to evaluate the gas flow behavior in shale nanopores. The result shows that the contributions of Darcy flow, slip flow and transition flow in shale nanopores are reciprocal, and are mainly dominated by pore radius and pressure. The adsorption effect greatly influences the total mass flux. The total mass flux will increase as Langmuir pressure and temperature increase while it will decrease with reservoir pressure and the adsorption thickness. These results can provide insights for a better understanding of gas flow in the shale nanopores so as to optimize the production performance of shale gas reservoirs.

Based on the isometric hypothesis, belowground plant biomass (MB) should scale isometrically with aboveground biomass (MA) and the scaling exponent should not vary with environmental factors. We tested this hypothesis using a large forest biomass database collected in China. Allometric scaling functions relating MB and MA were developed for the entire database and for different groups based on tree age, diameter at breast height, height, latitude, longitude or elevation. To investigate whether the scaling exponent is independent of these biotic and abiotic factors, we analyzed the relationship between the scaling exponent and these factors. Overall MB was significantly related to MA with a scaling exponent of 0.964. The scaling exponent of the allometric function did not vary with tree age, density, latitude, or longitude, but varied with diameter at breast height, height, and elevation. The mean of the scaling exponent over all groups was 0.986. Among 57 scaling relationships developed, 26 of the scaling exponents were not significantly different from 1. Our results generally support the isometric hypothesis. MB scaled near isometrically with MA and the scaling exponent did not vary with tree age, density, latitude, or longitude, but increased with tree size and elevation. While fitting a single allometric scaling relationship may be adequate, the estimation of MB from MA could be improved with size-specific scaling relationships.

The temperature sensitivity (Q10) of soil heterotrophic respiration (Rh) is an important ecological model parameter and may vary with temperature and moisture. While Q10 generally decreases with increasing temperature, the moisture effects on Q10 have been controversial. To address this, we conducted a 90-day laboratory incubation experiment using a subtropical forest soil with a full factorial combination of five moisture levels (20%, 40%, 60%, 80%, and 100% water holding capacity--WHC) and five temperature levels (10, 17, 24, 31, and 38°C). Under each moisture treatment, Rh was measured several times for each temperature treatment to derive Q10 based on the exponential relationships between Rh and temperature. Microbial biomass carbon (MBC), microbial community structure and soil nutrients were also measured several times to detect their potential contributions to the moisture-induced Q10 variation. We found that Q10 was significantly lower at lower moisture levels (60%, 40% and 20% WHC) than at higher moisture level (80% WHC) during the early stage of the incubation, but became significantly higher at 20%WHC than at 60% WHC and not significantly different from the other three moisture levels during the late stage of incubation. In contrast, soil Rh had the highest value at 60% WHC and the lowest at 20% WHC throughout the whole incubation period. Variations of Q10 were significantly associated with MBC during the early stages of incubation, but with the fungi-to-bacteria ratio during the later stages, suggesting that changes in microbial biomass and community structure are related to the moisture-induced Q10 changes. This study implies that global warming's impacts on soil CO2 emission may depend upon soil moisture conditions. With the same temperature rise, wetter soils may emit more CO2 into the atmosphere via heterotrophic respiration.

New tools are needed to study the intracellular pathogen Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), to facilitate new drug discovery and vaccine development. We have developed methodology to genetically incorporate unnatural amino acids into proteins in Mycobacterium smegmatis, BCG and Mtb, grown both extracellularly in culture and inside host cells. Orthogonal mutant tRNATyr/tyrosyl-tRNA synthetase pairs derived from Methanococcus jannaschii and evolved in Escherichia coli incorporate a variety of unnatural amino acids (including photocrosslinking, chemically reactive, heavy atom containing, and immunogenic amino acids) into proteins in response to the amber nonsense codon. By taking advantage of the fidelity and suppression efficiency of the MjtRNA/pIpaRS pair in mycobacteria, we are also able to use p-iodophenylalanine to induce the expression of proteins in mycobacteria both extracellularly in culture and inside of mammalian host cells. This provides a new approach to regulate the expression of reporter genes or mycobacteria endogenous genes of interest. The establishment of the unnatural amino acid expression system in Mtb, an intracellular pathogen, should facilitate studies of TB biology and vaccine development.

Background Our meta-analysis examines the effects of melatonin on wheat under varying abiotic stress conditions, focusing on photosynthetic parameters, chlorophyll fluorescence, leaf water status, and photosynthetic pigments. We initially collected 177 publications addressing the impact of melatonin on wheat. After meticulous screening, 31 published studies were selected, encompassing 170 observations on photosynthetic parameters, 73 on chlorophyll fluorescence, 65 on leaf water status, 240 on photosynthetic pigments. Results The analysis revealed significant heterogeneity across studies (I2 > 99.90%) for the aforementioned parameters and evidence of publication bias, emphasizing the complex interaction between melatonin application and plant physiological responses. Melatonin enhanced the overall response ratio (lnRR) for photosynthetic rates, stomatal conductance, transpiration rates, and fluorescence yields by 20.49, 22.39, 30.96, and 1.09%, respectively, compared to the control (no melatonin). The most notable effects were under controlled environmental conditions. Moreover, melatonin significantly improved leaf water content and reduced water potential, particularly under hydroponic conditions and varied abiotic stresses, highlighting its role in mitigating water stress. The analysis also revealed increases in chlorophyll pigments with soil drenching and foliar spray, and these were considered the effective application methods. Furthermore, melatonin influenced chlorophyll SPAD and intercellular CO2 concentrations, suggesting its capacity to optimize photosynthetic efficiency. Conclusions This synthesis of meta-analysis confirms that melatonin significantly enhances wheat’s resilience to abiotic stress by improving photosynthetic parameters, chlorophyll fluorescence, leaf water status, and photosynthetic pigments. Despite observed heterogeneity and publication bias, the consistent beneficial effects of melatonin, particularly under controlled conditions with specific application methods e.g. soil drenching and foliar spray, demonstrate its utility as a plant growth regulator for stress management. These findings encourage focused research and application strategies to maximize the benefits of melatonin in wheat farming, and thus contributing to sustainable agricultural practices. [ABSTRACT FROM AUTHOR]

The rapid advancements in artificial intelligence, particularly in the domains of robotics, prosthetics, and virtual and augmented reality (VR/AR), have driven an escalating demand for intuitive and effective human-machine interactions. Consequently, haptic devices, being electronic displays for the sense of touch, have drawn increasing attention. More efforts are in demand to develop stretchable and lightweight haptic devices that can trigger multiple mechanical cutaneous receptors using a single device. This work presents a new 3-modal 5-DOF stretchable haptic interface that is enabled by electromagnetic actuators and high-fidelity multi-layer metal printing. The haptic device renders rich haptic sensations (i.e., normal force, vibration, angular force, skin dragging) in one device, allowing for the comprehensive delivery of tactile information through the excitation of multiple cutaneous receptors. Additionally, haptic devices are designed to be compact, lightweight, and skin-compatible. The skin-like softness and stretchability enable intimate skin contact, which is crucial for efficient haptic information delivery. This feature prevents the impediment to natural movements of the skin and ensures the functional integrity of the device during daily deformations of the skin. Finally, three proof-of-concept demonstrations illustrate the potential of the reported multimodal haptic devices for advanced haptic interactions across various domains. [ABSTRACT FROM AUTHOR]

In our comprehensive meta-analysis, we initially collected 177 publications focusing on the impact of melatonin on wheat. After meticulous screening, 40 published studies were selected, encompassing 558 observations for antioxidant enzymes, 312 for reactive oxygen species (ROS), and 92 for soluble biomolecules (soluble sugar and protein). This analysis revealed significant heterogeneity across studies (I2 > 99% for enzymes, ROS, and soluble biomolecules) and notable publication bias, indicating the complexity and variability in the research field. Melatonin application generally increased antioxidant enzyme activities [superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX)] in wheat, particularly under stress conditions, such as high temperature and heavy-metal exposure. Compared to control, melatonin application increased SOD, POD, CAT, and APX activities by 29.5, 16.96, 35.98, and 171.64%, respectively. Moreover, oxidative stress markers like hydrogen peroxide (H2O2), superoxide anion (O2), and malondialdehyde (MDA) decreased with melatonin by 23.73, 13.64, and 21.91%, respectively, suggesting a reduction in oxidative stress. The analysis also highlighted melatonin's role in improving carbohydrate metabolism and antioxidant defenses. Melatonin showed an overall increase of 12.77% in soluble sugar content, and 22.76% in glutathione peroxidase (GPX) activity compared to the control. However, the effects varied across different wheat varieties, environmental conditions, and application methods. Our study also uncovered complex relationships between antioxidant enzyme activities and H2O2 levels, indicating a nuanced regulatory role of melatonin in oxidative stress responses. Our meta-analysis demonstrates the significant role of melatonin in increasing wheat resilience to abiotic stressors, potentially through its regulatory impact on antioxidant defense systems and stress response. [ABSTRACT FROM AUTHOR]