Potential molecular mechanisms of overgrazing-induced dwarfism in sheepgrass (Leymus chinensis) analyzed using proteomic data

BACKGROUND

This study was designed to reveal potential molecular mechanisms of long-term overgrazing-induced dwarfism in sheepgrass (Leymus chinensis).

METHODS

An electrospray ionisation mass spectrometry system was used to generate proteomic data of dwarf sheepgrass from a long-term overgrazed rangeland and normal sheepgrass from a long-term enclosed rangeland. Differentially expressed proteins (DEPs) between dwarf and normal sheepgrass were identified, after which their potential functions and interactions with each other were predicted. The expression of key DEPs was confirmed by high-performance liquid chromatography mass spectrometry (HPLC-MS) using a multiple reaction monitoring method.

RESULTS

Compared with normal sheepgrass, a total of 51 upregulated and 53 downregulated proteins were identified in dwarf sheepgrass. The amino acids biosynthesis pathway was differentially enriched between the two conditions presenting DEPs, such as SAT5_ARATH and DAPA_MAIZE. The protein-protein interaction (PPI) network revealed a possible interaction between RPOB2_LEPTE, A0A023H9M8_9STRA, ATPB_DIOEL, RBL_AMOTI and DNAK_GRATL. Four modules were also extracted from the PPI network. The HPLC-MS analysis confirmed the upregulation and downregulation of ATPB_DIOEL and DNAK_GRATL, respectively in dwarf samples compared with in the controls.

CONCLUSIONS

The upregulated ATPB_DIOEL and downregulated DNAK_GRATL as well as proteins that interact with them, such as RPOB2_LEPTE, A0A023H9M8_9STRA and RBL_AMOTI, may be associated with the long-term overgrazing-induced dwarfism in sheepgrass.

Effects of fertilizations on soil bacteria and fungi communities in a degraded arid steppe revealed by high through-put sequencing

Background

Fertilization as one of the measures in restoring degraded soil qualities has been introduced on arid steppes in recent decades. However, the fertilization use efficiency on arid steppes varies greatly between steppe types and years, enhancing uncertainties and risks in introducing fertilizations on such natural system to restore degraded steppes.

Methods

The experiment was a completely randomized design with five fertilization treatments, 0 (Control), 60 kg P ha⁻¹ (P), 100 kg N ha⁻¹ (N), 100 kg N ha⁻¹ plus 60 kg P ha⁻¹ (NP), and 4,000 kg sheep manure ha⁻¹ (M, equaling 16.4 kg P ha⁻¹ and 81.2 kg N ha⁻¹). Soils were sampled from a degraded arid steppe which was consecutively applied with organic and inorganic fertilizers for three years. We analyzed the diversity and abundance of soil bacteria and fungi using high-throughput sequencing technique, measured the aboveground biomass, the soil chemical properties (organic carbon, available and total phosphorus, available and total nitrogen, and pH), and the microbial biomass nitrogen and microbial biomass carbon.

Results

In total 3,927 OTU (operational taxonomic units) for bacteria and 453 OTU for fungi were identified from the tested soils. The Ace and Chao of bacteria were all larger than 2,400, which were almost 10 times of those of fungi. Fertilizations had no significant influence on the richness and diversity of the bacteria and fungi. However, the abundance of individual bacterial or fungi phylum or species was sensitive to fertilizations. Fertilization, particularly the phosphorus fertilizer, influenced more on the abundance of the AMF species and colonization. Among the soil properties, soil pH was one of the most important soil properties influencing the abundance of soil bacteria and fungi.

Discussion

Positive relationships between the abundance of bacteria and fungi and the soil chemical properties suggested that soil bacteria and fungi communities in degraded steppes could be altered by improving the soil chemical properties through fertilizations. However, it is still not clear whether the alteration of the soil microbe community is detrimental or beneficial to the degraded arid steppes.

Analysis of (CAG)n expansion in ATXN1, ATXN2 and ATXN3 in Chinese patients with multiple system atrophy

Multiple system atrophy (MSA) is a complex and multifactorial neurodegenerative disease, and its pathogenesis remains uncertain. Patients with MSA or spinocerebellar ataxia (SCA) show overlapping clinical phenotypes. Previous studies have reported that intermediate or long CAG expansions in SCA genes have been associated with other neurodegenerative disease. In this study, we screened for the number of CAG repeats in ATXN1, 2 and 3 in 200 patients with MSA and 314 healthy controls to evaluate possible associations between (CAG)_n in these three polyQ-related genes and MSA. Our findings indicated that longer repeat lengths in ATXN2 were associated with increased risk for MSA in Chinese individuals. No relationship was observed between CAG repeat length in the three examined genes and age at onset (AO) of MSA.

Fine-tuning the effects of auxiliary ligands on two trigonal-bipyramid cobalt(ii) complexes exhibiting field-induced slow magnetic relaxation

Two trigonal-bipyramid cobalt(ii) complexes exhibit field-induced slow magnetic relaxation effects due to their auxiliary ligands.

How do herders do well? Profitability potential of livestock grazing in Inner Mongolia, China, across ecosystem types

Livestock production has increased in Inner Mongolia, China, despite widespread documentation of grassland degradation. To begin investigating the relationship that produces these trends, we studied farm-level decisions of herder households. We estimated economic enterprise budgets for 15 counties in Inner Mongolia across five ecosystems in 2009 and 2014 by using household survey data. Six counties decreased livestock stocking rates and had improved profit over time. The remaining counties increased their stocking rates over the period studied and profit decreased for all but one county. Livestock operators who reported negative profit over the 5 years were located across ecosystem types and reported a large number of weather shocks that affected grassland availability. Removing the opportunity cost of land and labour from the economic enterprise budgets resulted in a positive profit for all counties, which may explain why herders continue to increase stocking rates with decreased grassland availability over time.

Enhanced gas separation performance of an ultramicroporous pillared-layer framework induced by hanging bare Lewis basic pyridine groups

An ultramicroporous pillared-layer framework exhibits extra high CO₂ and C₂ hydrocarbons over CH₄ separation performance under ambient conditions induced by hanging bare Lewis basic pyridine groups on the pore surface.

A novel microporous Tb-MOF fluorescent sensor for highly selective and sensitive detection of picric acid

A new three-dimensional metal–organic framework (MOF) sensor with molecular formula (C₂H₆NH₂)₂[Tb₂(ptptc)₂(DMF)(H₂O)]·DMF·6H₂O (complex 1) has been constructed from terphenyl-3,3′,5,5′-tetracarboxylic acid (H₄ptptc) and terbium nitrate under solvothermal conditions. The structure of complex 1 was characterized by single-crystal X-ray diffraction analysis (XRD), elemental analysis, IR spectroscopy and thermogravimetric (TG) analysis, and the purity was further confirmed by powder X-ray diffraction (PXRD) analysis. XRD analysis reveals that complex 1 crystallizes in a triclinic system P1̄ space group and consists of a three-dimensional anionic network which has one-dimensional channels. Fluorescence titration experiments showed that complex 1 displayed real-time, highly selective and sensitive fluorescence quenching behavior towards picric acid with a nanomolar scale experimental detection limit (100 nM). Recycling titration experiments suggested that the as-synthesized probe has good reversibility and can be used for at least five cycles in fluorescence titration experiments without obvious fluorescence intensity reduction or framework structure destruction. Furthermore, the high selectivity and sensitivity as well as good recyclability of complex 1 make it a potential fluorescent sensor for picric acid.

A new three-dimensional reusable Tb-MOF fluorescent sensor for the highly selective and sensitive detection of picric acid was reported.

Factors affecting herder adoption of winter lambing practices in the desert steppe region of Inner Mongolia, China

Although winter lambing practices (WL) have been shown to be a ‘win-win’ strategy for reducing the degradation of grasslands and improving herder livelihood in the pastoral regions of China, the adoption rate is still low. A survey was conducted to explore herders’ opinions of WL and other factors which influenced the adoption in the desert steppe region of Inner Mongolia, China. Herders who have spring lambing practices generally hold unfavourable opinions about WL. Most have only heard about WL but did not understand the detailed information of implementation or how it increases income. Herder ethnical background, distance to market and neighbours’ choices significantly affected the adoption rate. Han herders were more likely to adopt WL than Mongolian herders. Proximity to market led herders to be more market-focused and to adopt WL. Herders were more inclined to make the same choices as their neighbours. The results showed that herders were prepared to change and were carefully assessing the gains and losses of adopting WL. Results had implications for improving the adoption rate for WL and other livestock management practices in China.

Highly selective and sensitive detection of Hg2+, Cr2O72−, and nitrobenzene/2,4-dinitrophenol in water via two fluorescent Cd-CPs

Taking advantage of fluorescent Cd-CPs with 3,3′-thiodipropionic acid and imidazole ligands, herein, we demonstrate the synthesis of functional CPs, and develop two Cd-CP fluorescence sensing materials with highly selective and sensitive detection of Hg²⁺, Cr₂O₇²⁻, NB,/2,4-DNP in water.

Effects of temperature and grazing on soil organic carbon storage in grasslands along the Eurasian steppe eastern transect

Soil represents the largest terrestrial organic carbon pool. To address global climate change, it is essential to explore the soil organic carbon storage patterns and their controlling factors. We investigated the soil organic carbon density (SOCD) in 48 grassland sites along the Eurasian steppe eastern transect (ESET) region, which covers the Inner Mongolia grassland subregion and Mongolia grasslands subregion. Specifically, we analyzed the SOCD in the top 30 cm soil layer and its relationships with climatic variables, soil texture, grazing intensity and community biomass productivity. The results showed that the average SOCD of the ESET was 4.74 kg/m², and the SOCD of the Inner Mongolia grassland subregion (4.11 kg/m²) was significantly lower than that of the Mongolia grassland subregion (5.79 kg/m²). Significant negative relationships were found between the SOCD and the mean annual temperature (MAT), mean annual precipitation (MAP) and grazing intensity in the ESET region. The MAT and grazing intensity were identified as the major factors influencing the SOCD in the ESET region; the MAP and MAT were the major factors influencing the SOCD in the Inner Mongolia grassland subregion; and the MAT and soil pH were the major factors influencing the SOCD in the Mongolia grassland subregion.

p16 gene expression in pancreatic cancer tissue and its importance in diagnosis

The aim of this study was to assess the importance of p16 gene expressions in pancreatic cancer tissue for early diagnosis and treatment. Two groups were included in the study: an experimental group of 35 pancreatic cancer tissue specimens and a control group of 35 pancreatic cancer adjacent tissues collected during surgery. The expression of p16 gene in the two groups was observed using the immunohistochemical streptavidin peroxidase conjugated (S-P) method. The results were statistically interpreted using SPSS22.0 software. The positive expression rate of p16 in the experimental group was lower than that of the control group (p less than 0.05). Comparing the intensity of p16 gene expression, differentiation degree, clinical stage and metastases of nearby lymph nodes the differences had statistical significance (p less than 0.05). The intensity of p16 gene expression in high and medium differentiated pancreatic cancer group was higher than that of the low differentiated group. p16 gene expression in stages III and IV groups was lower than that in stages I and II groups. Differentiation degree, clinical stage, metastases of nearby lymph nodes and distant metastasss were negatively related with p16 gene expression (p less than 0.05). There was no correlation between age or gender and p16 gene expression. The decreased expression of p16 gene in pancreatic cancer tissue was negatively correlated with differentiation degree and clinical stage. Our results indicated that p16 can be used as a cue signal for diagnosing advanced pancreatic cancer.

Association of adiposity indices with bone density and bone turnover in the Chinese population

Associations of adiposity indices with bone mineral density (BMD) and bone turnover markers were evaluated in Chinese participants. Body mass index, fat mass, and lean mass are positively related to BMD in both genders. Subcutaneous fat area was proved to be negatively associated with BMD and positively correlated with osteocalcin in postmenopausal females.

INTRODUCTION

Obesity is highly associated with osteoporosis, but the effect of adipose tissue on bone is contradictory. Our study aimed to assess the associations of adiposity indices with bone mineral density (BMD) and bone turnover markers (BTMs) in the Chinese population.

METHODS

Our study recruited 5215 participants from the Shanghai area, evaluated related anthropometric and biochemical traits in all participants, tested serum BTMs, calculated fat distribution using magnetic resonance imaging (MRI) images and image analysis software, and tested BMD with dual-energy X-ray absorptiometry.

RESULTS

When controlled for age, all adiposity indices were positively correlated with BMD of all sites for both genders. As for the stepwise regression analysis, body mass index (BMI), fat mass, and lean mass were protective for BMD in both genders. However, subcutaneous fat area (SFA) was detrimental for BMD of the L1-4 and femoral neck (β ± SE -0.0742 ± 0.0174; p = 2.11E-05; β ± SE -0.0612 ± 0.0147; p = 3.07E-05). Adiposity indices showed a negative correlation with BTMs adjusting for age, especially with osteocalcin. In the stepwise regression analysis, fat mass was negatively correlated with osteocalcin (β ± SE -8.8712 ± 1.4902; p = 4.17E-09) and lean mass showed a negative correlation with N-terminal procollagen of type I collagen (PINP) for males (β ± SE -0.3169 ± 0.0917; p = 0.0006). In females, BMI and visceral fat area (VFA) were all negatively associated with osteocalcin (β ± SE -0.4423 ± 0.0663; p = 2.85E-11; β ± SE -7.1982 ± 1.1094; p = 9.95E-11), while SFA showed a positive correlation with osteocalcin (β ± SE: 5.5993 ± 1.1753; p = 1.98E-06).

CONCLUSION

BMI, fat mass, and lean mass are proved to be beneficial for BMD in both males and postmenopausal females. SFA is negatively associated with BMD and positively correlated with osteocalcin in postmenopausal females.

Aerobic exercise blocks interleukin-6 levels and germ cell apoptosis in obese rats

To investigate the effect of a high-fat diet and aerobic exercise intervention and its related mechanism on rat germ cell apoptosis. Forty male Sprague-Dawley rats were randomly divided into control group, high-fat diet group, control exercise group and high-fat exercise group. Rats were fed with high-fat diet or were given weight-free swimming. The levels of TG, TC, HDL, LDL and IL-6 in serum of rats were measured. The body weight, body length and inguinal fat weight were measured to calculate the Lee's index and lipid/body weight ratio. The expression of IL-6 mRNA in inguinal fat and IL-6R,Bcl-2 and Bax mRNA in testis was detected by RT-PCR. The morphological structure of testis was observed, and the Johnsen's ten-point score was calculated by HE staining, and the germ cell apoptosis was detected by TUNEL method. We got from the experimental results: a high-fat diet induces obesity and lipid metabolism disorder, alters testis morphological structure and increases germ cell apoptosis in rats. Aerobic exercise improves the lipid metabolism disorder and interferes with germ cell apoptosis by reducing interleukin-6 and interleukin-6 receptor expression.

Enzymatic production of sterculic acid from the novel Phoenix tree seed oil: Optimization and kinetic study

Phoenix tree (Firmiana simplex) seed oil is a novel oil which is rich in sterculic acid. Sterculic acid, a cyclopropene fatty acid, can be used as the inhibitor of the stearoyl-CoA desaturase system and mammary carcinomas growth. In this work, Lipozyme TLIM-catalyzed hydrolysis of the novel Phoenix tree seed oil was used to prepare sterculic acid. High temperature GC-FID and the degree of hydrolysis (DH) were used to monitor the reaction progress. Effects of reaction variables on the hydrolysis were evaluated and optimized using response surface methodology. Results showed that sterculic acid can be successfully prepared from the novel seed oil, and the effect of reaction variables on the hydrolysis decreased in the order of reaction time > enzyme load > temperature. A high yield of fatty acids (DH, 98.2±0.8%) can be obtained under optimized conditions (45 ºC, mass ratio of water to oil 10:1, enzyme load 10%, and 18 h). The Arrhenius equation for the hydrolysis was LnV0 = 9.12-4721/T. The activation energy was 39.25KJ/mol. The kinetic values for Vmax, K/m were 0.232mol/(L∙min) and 0.084 mol/L, respectively.

Long-Term Overgrazing-Induced Memory Decreases Photosynthesis of Clonal Offspring in a Perennial Grassland Plant

Previous studies of transgenerational plasticity have demonstrated that long-term overgrazing experienced by Leymus chinensis, an ecologically dominant, rhizomatous grass species in eastern Eurasian temperate grassland, significantly affects its clonal growth in subsequent generations. However, there is a dearth of information on the reasons underlying this overgrazing-induced memory effect in plant morphological plasticity. We characterized the relationship between a dwarf phenotype and photosynthesis function decline of L. chinensis from the perspective of leaf photosynthesis by using both field measurement and rhizome buds culture cultivated in a greenhouse. Leaf photosynthetic functions (net photosynthetic rate, stomatal conductance, intercellular carbon dioxide concentration, and transpiration rate) were significantly decreased in smaller L. chinensis individuals that were induced to have a dwarf phenotype by being heavily grazed in the field. This decreased photosynthetic function was maintained a generation after greenhouse tests in which grazing was excluded. Both the response of L. chinensis morphological traits and photosynthetic functions in greenhouse were deceased relative to those in the field experiment. Further, there were significant decreases in leaf chlorophyll content and Rubisco enzyme activities of leaves between bud-cultured dwarf and non-dwarf L. chinensis in the greenhouse. Moreover, gene expression patterns showed that the bud-cultured dwarf L. chinensis significantly down-regulated (by 1.86- to 5.33-fold) a series of key genes that regulate photosynthetic efficiency, stomata opening, and chloroplast development compared with the non-dwarf L. chinensis. This is among the first studies revealing a linkage between long-term overgrazing affecting the transgenerational morphological plasticity of clonal plants and physiologically adaptive photosynthesis function. Overall, clonal transgenerational effects in L. chinensis phenotypic traits heavily involve photosynthetic plasticity.

Diurnal variations and source apportionment of ozone at the summit of Mount Huang, a rural site in Eastern China

Comprehensive measurements were conducted at the summit of Mount (Mt.) Huang, a rural site located in eastern China during the summer of 2011. They observed that ozone showed pronounced diurnal variations with high concentrations at night and low values during daytime. The Weather Research and Forecasting with Chemistry (WRF-Chem) model was applied to simulate the ozone concentrations at Mt. Huang in June 2011. With processes analysis and online ozone tagging method we coupled into the model system, the causes of this diurnal pattern and the contributions from different source regions were investigated. Our results showed that boundary layer diurnal cycle played an important role in driving the ozone diurnal variation. Further analysis showed that the negative contribution of vertical mixing was significant, resulting in the ozone decrease during the daytime. In contrast, ozone increased at night owing to the significant positive contribution of advection. This shifting of major factor between vertical mixing and advection formed this diurnal variation. Ozone source apportionment results indicated that approximately half was provided by inflow effect of ozone from outside the model domain (O_3-INFLOW) and the other half was formed by ozone precursors (O_3-PBL) emitted in eastern, central, and southern China. In the O_3-PBL, 3.0% of the ozone was from Mt. Huang reflecting the small local contribution (O_3-LOC) and the non-local contributions (O_3-NLOC) accounted for 41.6%, in which ozone from the southerly regions contributed significantly, for example, 9.9% of the ozone originating from Jiangxi, representing the highest geographical contributor. Because the origin and variation of O_3-NLOC was highly related to the diurnal movements in boundary layer, the similar diurnal patterns between O_3-NLOC and total ozone both indicated the direct influence of O_3-NLOC and the importance of boundary layer diurnal variations in the formation of such distinct diurnal ozone variations at Mt. Huang.

CNGC2 Is a Ca2+ Influx Channel That Prevents Accumulation of Apoplastic Ca2+ in the Leaf

Ca²⁺ is absorbed by roots and transported upward through the xylem to the apoplastic space of the leaf, after which it is deposited into the leaf cell. In Arabidopsis (Arabidopsis thaliana), the tonoplast-localized Ca²⁺/H⁺ transporters CATION EXCHANGER1 (CAX1) and CAX3 sequester Ca²⁺ from the cytosol into the vacuole, but it is not known what transporter mediates the initial Ca²⁺ influx from the apoplast to the cytosol. Here, we report that Arabidopsis CYCLIC NUCLEOTIDE-GATED CHANNEL2 (CNGC2) encodes a protein with Ca²⁺ influx channel activity and is expressed in the leaf areas surrounding the free endings of minor veins, which is the primary site for Ca²⁺ unloading from the vasculature and influx into leaf cells. Under hydroponic growth conditions, with 0.1 mm Ca²⁺, both Arabidopsis cngc2 and cax1cax3 loss-of-function mutants grew normally. Increasing the Ca²⁺ concentration to 10 mm induced H₂O₂ accumulation, cell death, and leaf senescence and partially suppressed the hypersensitive response to avirulent pathogens in the mutants but not in the wild type. In vivo apoplastic Ca²⁺ overaccumulation was found in the leaves of cngc2 and cax1cax3 but not the wild type under the 10 mm Ca²⁺ condition, as monitored by Oregon Green BAPTA 488 5N, a low-affinity and membrane-impermeable Ca²⁺ probe. Our results indicate that CNGC2 likely has no direct roles in leaf development or the hypersensitive response but, instead, that CNGC2 could mediate Ca²⁺ influx into leaf cells. Finally, the in vivo extracellular Ca²⁺ imaging method developed in this study provides a new tool for investigating Ca²⁺ dynamics in plant cells.

Selection of Reference Genes for qRT-PCR Analysis of Gene Expression in Stipa grandis during Environmental Stresses

Stipa grandis P. Smirn. is a dominant plant species in the typical steppe of the Xilingole Plateau of Inner Mongolia. Selection of suitable reference genes for the quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) is important for gene expression analysis and research into the molecular mechanisms underlying the stress responses of S. grandis. In the present study, 15 candidate reference genes (EF1 beta, ACT, GAPDH, SamDC, CUL4, CAP, SNF2, SKIP1, SKIP5, SKIP11, UBC2, UBC15, UBC17, UCH, and HERC2) were evaluated for their stability as potential reference genes for qRT-PCR under different stresses. Four algorithms were used: GeNorm, NormFinder, BestKeeper, and RefFinder. The results showed that the most stable reference genes were different under different stress conditions: EF1beta and UBC15 during drought and salt stresses; ACT and GAPDH under heat stress; SKIP5 and UBC17 under cold stress; UBC15 and HERC2 under high pH stress; UBC2 and UBC15 under wounding stress; EF1beta and UBC17 under jasmonic acid treatment; UBC15 and CUL4 under abscisic acid treatment; and HERC2 and UBC17 under salicylic acid treatment. EF1beta and HERC2 were the most suitable genes for the global analysis of all samples. Furthermore, six target genes, SgPOD, SgPAL, SgLEA, SgLOX, SgHSP90 and SgPR1, were selected to validate the most and least stable reference genes under different treatments. Our results provide guidelines for reference gene selection for more accurate qRT-PCR quantification and will promote studies of gene expression in S. grandis subjected to environmental stress.

Overgrazing induces alterations in the hepatic proteome of sheep (Ovis aries): an iTRAQ-based quantitative proteomic analysis

Background

The degradation of the steppe of Inner Mongolia, due to overgrazing, has resulted in ecosystem damage as well as extensive reductions in sheep production. The growth performance of sheep is greatly reduced because of overgrazing, which triggers massive economic losses every year. The liver is an essential organ that has very important roles in multiple functions, such as nutrient metabolism, immunity and others, which are closely related to animal growth. However, to our knowledge, no detailed studies have evaluated hepatic metabolism adaption in sheep due to overgrazing. The molecular mechanisms that underlie these effects remain unclear.

Methods

In the present study, our group applied isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomic analysis to investigate changes in the protein profiles of sheep hepatic tissues when nutrition was reduced due to overgrazing (12.0 sheep/ha), with the goal of characterizing the molecular mechanisms of hepatic metabolism adaption in sheep in an overgrazing condition.

Results

The body weight daily gain of sheep was greatly decreased due to overgrazing. Overall, 41 proteins were found to be differentially abundant in the hepatic tissue between a light grazing group and an overgrazing group. Most of the differentially expressed proteins identified are involved in protein metabolism, transcriptional and translational regulation, and immune response. In particular, the altered abundance of kynureninase (KYNU) and HAL (histidine ammonia-lyase) involved in protein metabolic function, integrated with the changes of serum levels of blood urea nitrogen (BUN) and glucose (GLU), suggest that overgrazing triggers a shift in energy resources from carbohydrates to proteins, causing poorer nitrogen utilization efficiency. Altogether, these results suggest that the reductions in animal growth induced by overgrazing are associated with liver proteomic changes, especially the proteins involved in nitrogen compounds metabolism and immunity.

Conclusions

This provides new information that can be used for nutritional supplementation to improve the growth performance of sheep in an overgrazing condition.

Electronic supplementary material

The online version of this article (doi:10.1186/s12953-016-0111-z) contains supplementary material, which is available to authorized users.

Patterns of herders’ adaptation to changes in social–ecological systems across northern China’s grasslands over the past three decades

Understanding the changes in herders’ adaptation to environmental change can provide insight into humans’ adaptive mechanisms to different social–ecological systems, and is also important for the optimal management of grasslands. However, the existing and emerging patterns of herders’ adaptation to changes in social–ecological systems across different types of grasslands are poorly understood. This paper presents a systematic participatory investigation that was conducted to comprehensively understand herders’ adaptation in this context over the past three decades. Three counties in Inner Mongolia grasslands were selected as the case study sites, located in meadow steppe, typical steppe and desert steppe respectively. Our results indicate that herders’ perceptions partly fit with the reality of the actual changes. The majority of herders attributed their pasture’s quality degradation to reduced precipitation rather than overgrazing, a contradictory perception to previous scientific observations (overgrazing > climate change). Moreover, herders’ behaviour in relation to herbage storage and livestock structure had dramatically changed in terms of spatial and temporal patterns in Inner Mongolia, which benefited herders in production efficiency. Lambing time of sheep and goats occurred earlier than it did several decades ago across the three grassland types. This was attributed to a rise in temperature, increasing marketisation and developing infrastructure. In addition, there became evident a transformation in the animal husbandry production cycle from a two-year to one-year cycle. Our results highlighted that the transformation of herders’ behavioural strategies resulted from variations in spatial and temporal patterns of climate change, pasture degradation, new policies and marketisation in pastoral areas. These strategies can be seen as key mechanisms in long-term adaptation to changes in social–ecological systems, which benefit herders’ efficiency in grassland management.

Purification and electronic characterisation of 18 isomers of the OPV acceptor material bis-[60]PCBM

The as-produced isomer mixture of the organic photovoltaic device acceptor material bis-[60]PCBM has been purified into its constituents by peak-recycling HPLC, and those individual isomers were characterised by UV-Vis absorption spectroscopy and cyclic voltammetry.

Imaging study of using radiopharmaceuticals labeled with cyclotron-produced 99mTc

Cyclotron-produced ^99mTc (CPTc) has been recognized as an attractive and practical substitution of reactor/generator based ^99mTc. However, the small amount of ^92-98Mo in the irradiation of enriched ¹⁰⁰Mo could lead to the production of other radioactive technetium isotopes (Tc-impurities) which cannot be chemically separated. Thus, these impurities could contribute to patient dose and affect image quality. The potential radiation dose caused by these Tc-impurities produced using different targets, irradiation conditions, and corresponding to different injection times have been investigated, leading us to create dose-based limits of these parameters for producing clinically acceptable CPTc. However, image quality has been not considered. The aim of the present work is to provide a comprehensive and quantitative analysis of image quality for CPTc. The impact of Tc-impurities in CPTc on image resolution, background noise, and contrast is investigated by performing both Monte-Carlo simulations and phantom experiments. Various targets, irradiation, and acquisition conditions are employed for investigating the image-based limits of CPTc production parameters. Additionally, the relationship between patient dose and image quality of CPTc samples is studied. Only those samples which meet both dose- and image-based limits should be accepted in future clinical studies.