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The present study was designed to investigate the influence of Se deficiency on serum histamine concentration and the expression of histamine receptor in the jejunum of chickens. Forty neonatal chickens were randomly divided into two groups. Experimental chickens were fed a low-Se diet (0.034 mg/kg), whereas chickens in the control group were fed a diet with a Se level of 0.229 mg/kg. Ten chickens were sacrificed on days 30, 45, 60 and 75. Blood and jejunum samples were collected. Histamine concentration in the jejunum was measured by ELISA, the jejunal mast cell (MC) ultrastructure was studied by transmission electron microscopy, and the expression level of histamine H2 receptor (H2R) mRNA in the jejunum was examined using real-time PCR. Results: The jejunal histamine concentration in chickens fed the low-Se diet was significantly higher than that in the control group (P<0.01). Se deficiency induced degranulation of MC in the jejunum of chickens in the low-Se diet group; their cytoplasm was filled with fused granules and vacuoles. The expression level of jejunal H2R mRNA in chickens fed the low-Se diet was also significantly higher than that in the control group (P<0.01). The results obtained suggest that Se deficiency stimulates MC degranulation and release of histamine, binding H2R promotes both regulation of digestion and cell proliferation while protects the jejunum from injury induced by Se deficiency.
Genome-wide gene expression profiling was conducted by Solexa sequencing in order to gain insight into the transcriptome dynamics that are associated with salt stress of cotton seedlings. A total of 145,794 and 138,518 clean tags were generated from the control and salinity libraries, respectively. Of these, 75,500 (51.8%) and 72,077 (52.0%) tags were matched to the reference genes. The most differentially regulated tags with a log2ratio >2 or >-2 (P <0.001) were analyzed further, representing 125 up- and 171 down-regulated genes except for unknown transcripts, which were classified into ten functional categories. The most enriched categories were those of metabolism, signaling pathway, environmental response and transcription. Many genes or biological pathways were found to be commonly shared between salt and other abiotic stresses in plants such as genes participating in environmental response, ABA signaling JA signaling, etc. Furthermore, the expression patterns of 12 genes were assessed by quantitative real-time PCR, and the results obtained showed general agreement with the Solexa data. Further analysis indicated the important roles of selected genes in salt tolerance by comparison with the mRNA levels in salt-tolerant cotton cultivar ZM3 with that in salt-sensitive cultivar LM6. Overall, we reveal the complex changes at the transcriptional level during salt stress of cotton seedlings and provide useful starting points for more in-depth analyses of cotton’s salt tolerance.
Food availability is important to the dynamics of animal social organizations or populations. However, the role of winter food availability in animal population dynamics is still controversial. We carried out an experimental study to test Lack’s hypothesis that reduced food in winter limits survival and spring numbers of breeding individuals of social groups, using the Mongolian gerbil (Meriones unguiculatus) as model species. We established 24 gerbil social groups in 24, 10 × 10 m, pens in September 2008. We provided wheat seeds as supplemental food in 12 enclosures from September 2008 to March 2009; the other 12 enclosures, not provided with supplemental food, served as controls. We live-trapped gerbils at a 2-week interval from September to April. Supplemental food during winter increased biweekly survival by 10% relative to that in control groups. Only four control social groups survived to the end of our study whereas all 12 food-supplemented social groups survived through our study period. Supplemental food also increased cumulative numbers of recruits and group sizes of gerbils. We conclude that winter food availability limits winter survival and spring social groups or population sizes of Mongolian gerbils.
The main aim of this study was to describe the adsorption behaviours of acetaminophen (APAP) onto colloid and solid particle in sediment in terms of their impact on the factors of the processes (e.g., contact time, temperature, kinetic, thermodynamic characteristics) that were analyzed systematically. Sediment was collected from a typical tributary in the mid-Weihe River and a separation device was employed to separate sediment into colloid and solid particle. Results show that the adsorption of APAP onto colloid and solid particle reached equilibrium after about 12 hours and 48 hours, respectively. The adsorption capacity of APAP onto colloid was at least 28-fold larger than that onto solid particle with an initial APAP concentration of 10.0 mg·L⁻¹ at 25ºC. The Langmuir isotherm model was more suitable for describing the adsorption behaviours of APAP onto both colloid and solid particle in sediment. The adsorption processes were feasible, spontaneous, entropyincreasing, and endothermic in nature, the adsorption capacity increased with increasing temperature. The mechanisms controlling APAP adsorption onto colloid and solid particle were mainly physisorption, but physisorption less on APAP adsorption onto colloid. The obtained results provide a theoretical basis for the effective prevention of APAP pollution to the groundwater system in the Weihe River basin.
Agriculture is one of the main sources of anthropogenic greenhouse gases on the earth, but it also serves as a carbon sink, which has great potential for greenhouse gas absorption. Based on the scientific calculation system of carbon emissions and carbon sinks in agriculture, we calculated the carbon emissions and carbon sinks of agriculture using data from Hotan Prefecture for the period 1999-2014. The results showed that the net carbon sink (total carbon sinks and total carbon emissions) showed a stable increase trend in Hotan during 1999-2014. The carbon sinks level of agriculture in Hotan prefecture is more than three times of that in China and more than two times that in Xinjiang. Thus, the agricultural carbon sinks function of Hotan is obvious. To realize sustainable agricultural development and to transform agricultural carbon sinks into the power to promote regional economic development, we established the ecological compensation mechanism of agricultural carbon sinks from the aspects of the main body of compensation, compensation principle, compensation method, and compensation standard within the premise of the ecological function of carbon sinks in agriculture. We use the net carbon sinks amount multiplied by the unit price of carbon sinks to obtain the amount of agricultural carbon sinks compensation in this paper. Compensation methods include government compensation and market compensation. Government compensation mainly comprises financial, material, policy, and technical compensation. Market compensation mainly uses the carbon trading platform to compensate for the net carbon sinks of agriculture.
Whether and why the biomass–density (M–N) scaling relationship varies along environmental gradients were continuously debated in theoretical ecology. In this study, how soil salinity stress affects on the M–N scaling relationship was investigated by using Suaeda salsa L. in beach of Dongtai, Jiangsu Province, China. The results showed that the exponent of the scaling relationship (b) of low salinity level (-1.259) was smaller than that of middle salinity level (-1.025), which in turn was smaller than that high salinity level (-0.698). The plant height–crown radius (H–r) scaling exponents (ϭ) decreased with increasing salinity stress, while the canopy coverage–density (C–N) scaling exponents (β) showed an inverse trend. The predict data (b) based on ϭ and β by using the geometric model were statistically indistinguishable from their observed values for the three salinity levels. Moreover, two resources utilization parameters (l mean from root to leaf, a total area of leaves) of metabolic theory, photosynthetic rate, and water-use efficiency were more advantageous to Suaeda salsa L. of high stress than to those of low salinity. Therefore, it was implied that the changes of M–N relationship along salinity gradients may be resulted from their different geometric morphologies and resource utilization in response to salinity stress.
For investigating the protective roles of antioxidative system in desiccation tolerance of Caragana species as they adapt to arid environments, we monitored a variety of ecophysiological parameters in the leaves of Caragana arborescens (mesophyte), C. microphylla (semiarid species), C. roborovskyi, C. stenophylla, C. acanthophylla, and C. tragacanthoides (xerophyte) grown under a drying-rehydration cycle. Relative leaf water content and chlorophyll content were decreased by 17.4–39.2 %, and by 14–40 %, respectively, after exposure to 48 days of drought stress. Malondialdehyde did not increase in xeric Caragana species. Hydrogen peroxide concentrations increased by 13.1–43.9 % except in C. acanthophylla. The activities of superoxide dismutase (SOD), guaiacol peroxidase (POD), ascorbate peroxidase (APX), glutathione reductase (GR) and reduced glutathione (GSH) in xeric Caragana species were significantly elevated with progressing drought stress. However, catalase in all species decreased markedly before drought stress treatment reached 40 days. The xeric Caragana species showed higher SOD, POD, APX, and GR activities, as well as ascorbate content, and more manganese SOD isoenzymes. C. arborescens and C. microphylla accumulated more free proline. Our data indicate that SOD and POD with the ascorbate–glutathione cycle have important protective effects in xeric Caragana species under drought stress. Free proline may be crucial in the resistance of C. arborescens and C. microphylla to drought stress.
In an artificial island construction project based on the large-scale marine reclamation land, the soil settlement is a key to affect the late safe operation of the whole field. To analyze the factors of the soil settlement in a marine reclamation project, the SEM method in the soil micro-structural analysis method is used to test and study six soil samples such as the representative silt, mucky silty clay, silty clay and clay in the area. The structural characteristics that affect the soil settlement are obtained by observing the SEM charts at different depths. By combining numerical calculation method of Terzaghi’s one-dimensional and Biot’s two-dimensional consolidation theory, the one-dimensional and two-dimensional creep models are established and the numerical calculation results of two consolidation theories are compared in order to predict the maximum settlement of the soils 100 years after completion. The analysis results indicate that the micro-structural characteristics are the essential factor to affect the settlement in this area. Based on numerical analysis of one-dimensional and two-dimensional settlement, the settlement law and trend obtained by two numerical analysis method is similar. The analysis of this paper can provide reference and guidance to the project related to the marine reclamation land
The following three new species of the genus Tegolophus Keifer from Oriental China are described and illustrated in this paper. They are: Tegolophus carmonae sp. nov. infesting Carmona microphylla (Lam.) G. Don. (Boraginaceae), Tegolophus corylopsus sp. nov. infesting Corylopsis glandulifera Hemsl. (Hamamelidaceae) and Tegolophus miscanthus sp. nov. infesting Miscanthus floridulus (Lab.) Warb (Poaceae).
A new mathematical equation is introduced in this paper: w = f - 1/(b/f +(1/(f-s)-b-f)exp(kt)) where W is the size at any convenient unit of time /, s is the initial size, f is the upper asympotic size, k is the growth coefficient (k > 0), and b is the constant. The new equation encompasses the logistic equation and therefore should be considered as a generalized version of the classical logistic equation. With its additional fourth para­meter 6, the new equation yields an unfixed value of inflexion point which enables it to possess good flexibility for depicting diverse growth patterns. In order to evaluate the fitness of the new growth equation, some commonly encountered models are compared to the new one using 12 sets of somatic growth data of mammalian species including hamster, rat, vole, pika, mouse, rabbit, cattle, and bear, The new equation possesses excellent fitness to each data set, suggesting that it is worth being considered by growth data analysts.
Wildlife collisions with aircraft (hereafter incidents) threaten human safety and cause substantial economic loss. Although more than 97% of wildlife incidents with U.S. civil aircraft involve birds, damage is more than 4.5 times more likely to occur during a mammal incident (e.g., deer, canids). Bats are the only mammals with the potential to be struck by aircraft outside the airport environment (at least 152.4 m above ground). We examined the Federal Aviation Administration's (FAA) National Wildlife Strike Database from 1990 to 2010 to estimate the frequency of bat incidents with aircraft within the U.S. and the risk relative to other wildlife incidents. We summarized 417 bat incidents with U.S. civil aircraft. There were 10 bat species or species groups involved in these incidents; however, 68.9% were not identified to species. Most (85.7%) bat incidents occurred at Part 139 certificated airports that receive regularly-scheduled passenger flights with more than nine seats or unscheduled flights with more than 30 seats. More incidents occurred during August (28.3%) than any other month. Most bat incidents occurred at night (81.7%), but the greatest incident rate occurred at dusk (57.3%). More incidents occurred during aircraft landing (85.0%) than take-off (11.2%) or other phases of flight (3.7%). ‘Minor’ damage to aircraft occurred on only two occasions but no damage costs were reported. Incidents coincided with bat behavior, including diel activity, migration, hibernation, and juvenile recruitment. We conclude bat incidents are low risk to U.S. civil aircraft and have minimal economic effect on the U.S. civil aviation industry.
We investigated the response of Mn-hyperaccumulator Phytolacca americana L. to manganese excess as well as the relationships between lignin deposition in the plant’s leaves, peroxidase and laccase activities in the leaf apoplast, and Mn toxicity. The exceptionally high tolerance of P. americana to Mn, both in solution and in tissue, was confirmed. No visible brown spot was observed in the leaves of plants treated with B10,000 µM Mn for 10 days. Mn treatment significantly increased lignin content and laccase activity in the apoplastic washing fluid (AWF) of P. americana leaves. In contrast, an increase in the Mn supply was paralleled by a significant decrease in the concentration of total phenolic compounds (TPCs) and in water-soluble guaiacol peroxidase (SPOD) activity in leaf AWF. This result suggested that an increase in lignin deposition decreased the concentration of apoplastic TPCs that are available to generate potentially toxic intermediates by acting as peroxidase substrates. Thus, data of the present study indicate that lignin formation by laccase activities reduces Mn toxicity and increases Mn tolerance of P. americana by depressing SPOD-mediated formation of toxic intermediates from TPCs.
This paper studies organic matter (OM) and nitrogen (N) distributions at different depths of an earthworm packing bed, and the N distribution in situ solution in artificial soil (AS). The contents of OM, nitrate nitrogen (NO₃-N), ammonia nitrogen (NH₃-N), and total nitrogen (TN) changed along with the depth of AS. The results of N concentration in situ solution indicated that 35 cm to 40 cm thickness of earthworm packing bed thickness was optimal for removing NH₃-N and TN for synthetic wastewater treatment. Fourier transform infrared spectra showed that most intensity variations of the absorbance peaks increased in AS, decreased in detritus, and slightly changed in sand after synthetic wastewater treatment. Furthermore, certain functional chemical attributes might evaluate the OM contents at the VF media, and AS could act as the main matrices for OM reaction.
To explore the role of the integrin signaling pathway in hepatocytes during rat liver regeneration, the integrin signaling pathway-related gene expression profile in hepatocytes of regenerative liver was detected using Rat Genome 230 2.0 array. The chip data showed that 265 genes of the integrin signaling pathway were included by Rat Genome 230 2.0 array and 132 genes showed significant expression changes in hepatocytes of regenerative liver. The numbers of up-, down- and up/down-regulated genes were 110, 15 and 7 respectively. In addition, bioinformatics and systems biology methods were used to analyze the role of the integrin signaling pathway in hepatocytes. The analysis of gene synergy value indicated that paths 1, 8, 12, and 15 promoted hepatocyte proliferation at the priming phase of liver regeneration; paths 1, 3, 8, and 12–15 enhanced hepatocyte proliferation at the progressing phase; paths 11 and 14 promoted hepatocyte proliferation, while paths 12 and 13 reduced hepatocyte proliferation at the terminal phase. Additionally, the other 8 paths (2, 4, 5–7, 9–10, and 16) were not found to be related to liver regeneration. In conclusion, 132 genes and 8 cascades of the integrin signaling pathway participated in regulating hepatocyte proliferation during rat liver regeneration.
This paper analysed the influence of the gradient of water levels (-54–120 cm) on Acorus calamus (A. calamus) young shoots in terms of their growth characteristics (germination rate, basal stem, height and biomass), leaf characteristics (number, area and moisture content), chlorophyll (chl) fluorescence parameters (Fv/ Fm, ETR, qP and qN) and other indicators. Based on a Gaussian model, we determined and quantified the response relationship between A. calamus young shoots and water level. The results showed that the ecological amplitude of water level for A. calamus young shoots was -52.3−141.8 cm, and the optimum range was -3.5−69.3 cm; a variety of indicators suggested that the optimum depth for A. calamus young shoots was from18.8 cm to 49.6 cm. The A. calamus seedling growth characteristics which were sensitive to changes in the water level were the germination rate and biomass. The germination rate was more sensitive to the submergence water depth, but the biomass was obviously influenced by the groundwater depth. Therefore, the A. calamus could be a suitable species for ecological restoration of land/inland water ecotones in lakes, rivers and reservoirs.
Tropical forests are among the most complex ecosystems on Earth. The high alpha-diversity of tropical forests has been amply documented, however, beta diversity, equally important for us to understand the mechanism of biodiversity maintenance, has seldom been studied. The main current hypotheses about the origin of beta diversity are as follows: (1) species composition is uniform over large areas; (2) species composition fluctuates in a random, auto-correlated way emphasizing spatially limited dispersal; (3) species composition is related to environmental conditions. Testing these hypotheses is important to understand ecosystem function and to manage ecosystems effectively. In this study, we quantified the relative influence of environmental variation and spatial distance on the beta diversity of woody plant functional groups in a tropical forest of Hainan Island, China. Floristic and environmental data were collected from 135 grid-sample plots. We classified woody plant functional groups based on frequency, growth forms and successional status, respectively. To see whether environmental variation and spatial distance influence beta diversity, the simple and partial Mantel tests, in conjunction with linear and spline regression models were performed. The results showed that environmental heterogeneity and spatial distance were the primary determinants of pair-wise species composition differences between plots in the study area. Common, tree and climax species were more sensitive than the others to changes in environmental heterogeneity and spatial distance. Except for rare, pioneer and shrub species, the others had apparently negative relationship between spatial distance and similarity. The distance decay of similarity was determined by joint influences of spatial distance and spatially-structured environmental variables. Spatial distance had the clearest effect on beta diversity at distances <15 km and with the increase in spatial distance, beta diversity was gradually controlled by environmental heterogeneity. This study provides further support for neutral theory and environmental control hypothesis as opposed to uniformly distributed hypothesis.
Leaf carbon isotope composition (δ¹³C) of both vascular and non-vascular plants were investigated in order to assess their variability along an altitude gradient (414, 620, 850, 1086, 1286 and 1462 m) from a subtropical monsoon forest located at Mt. Tianmu Reserve, eastern China. Leaf δ¹³C values of all plant species ranged from -34.4 to -26.6‰, with an average of -29.8‰. There is no significant difference in leaf δ¹³C between vascular plants and mosses, however, trees had significantly higher δ¹³C values than herbs. For pooled data, leaf δ¹³C was positively correlated with altitude. Leaf δ¹³C was significantly and negatively correlated with annual mean temperature and atmospheric pressure, while it was significantly and positively correlated with soil water content. Furthermore, there was no relationship between leaf δ¹³C and soil nitrogen content or soil phosphorus content. The altitudinal trend in leaf δ¹³C is the consequence of the interaction between temperature, atmospheric pressure and soil water content.
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