Impact of grassland contract policy on soil organic carbon losses from alpine grassland on the Qinghai–Tibetan Plateau          下载免费PDF全文

J. Cao  Y. Gong  E. T. Yeh  N. M. Holden  J. F. Adamowski  R. C. Deo  M. Liu  J. Zhou  J. Zhang  W. Zhang  S. Zhang  D. Sheng  S. Yang  X. Xu  M. Li  Q. Feng 《Soil Use and Management》2017,33(4):663-671

Carbon storage in the soils on the Qinghai–Tibetan Plateau plays a very important role in the global carbon budget. In the 1990s, a policy of contracting collective grasslands to smaller units was implemented, resulting in a change from the traditional collective grassland management to two new management patterns: a multi‐household management pattern (MMP: grassland shared by several households without enclosures) and a single‐household management pattern (SMP: grassland enclosed and used by only one household). In 2016, 50 MMP and 54 SMP winter pastures on the Qinghai–Tibetan Plateau were sampled to assess the differences in soil organic carbon (SOC) between the two management patterns. Results showed that average SOC was significantly greater under MMP than under SMP, with an estimated 0.41 Mg C/ha/yr lost due to SMP following the new grassland contract. Based on the government's grassland policy, four grassland utilization scenarios were developed for both summer and winter pastures. We found that if the grassland were managed under SMP, likely C losses ranged between 0.31 × 10⁷ and 6.15 × 10⁷ Mg C/yr across the Qinghai–Tibetan Plateau relative to MMP, which more closely resembles pre‐1990s grassland management. Previous estimates of C losses have only considered land use change (with cover change) and ignored the impacts driven by land management pattern changes (without cover change). The new data suggest that C losses from the Qinghai–Tibetan Plateau are greater than previously estimated, and therefore that the grassland contract policy should be reviewed and SMP households should be encouraged to reunite into the MMP. These findings have potential implications for land management strategies not only on the Qinghai–Tibetan Plateau but also other grazing regions globally where such practices may exist.  相似文献   

EPS364, a Novel Deep-Sea Bacterial Exopolysaccharide,Inhibits Liver Cancer Cell Growth and Adhesion     

Yun Wang  Ge Liu  Rui Liu  Maosheng Wei  Jinxiang Zhang  Chaomin Sun 《Marine drugs》2021,19(3)

The prognosis of liver cancer was inferior among tumors. New medicine treatments are urgently needed. In this study, a novel exopolysaccharide EPS364 was purified from Vibrio alginolyticus 364, which was isolated from a deep-sea cold seep of the South China Sea. Further research showed that EPS364 consisted of mannose, glucosamine, gluconic acid, galactosamine and arabinose with a molar ratio of 5:9:3.4:0.5:0.8. The relative molecular weight of EPS364 was 14.8 kDa. Our results further revealed that EPS364 was a β-linked and phosphorylated polysaccharide. Notably, EPS364 exhibited a significant antitumor activity, with inducing apoptosis, dissipation of the mitochondrial membrane potential (MMP) and generation of reactive oxygen species (ROS) in Huh7.5 liver cancer cells. Proteomic and quantitative real-time PCR analyses indicated that EPS364 inhibited cancer cell growth and adhesion via targeting the FGF19-FGFR4 signaling pathway. These findings suggest that EPS364 is a promising antitumor agent for pharmacotherapy.  相似文献   

Genome-wide identification of citrus CAMTA genes and their expression analysis under stress and hormone treatments     

Jing Zhang  Xiaoting Pan  Ting Ge  Shilai Yi  Qiang Lv  Yongqiang Zheng 《The Journal of Horticultural Science and Biotechnology》2019,94(3):331-340

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优化预处理及脱毒工艺以制备玉米芯半纤维素水解液     

王家旺  杨晓峰  刘国明  葛菁萍 《中国农学通报》2020,36(20):28-35

为了降低玉米芯半纤维素水解液中的乙酸、糠醛和酚类等有毒物质含量,使可利用糖类含量增加。本研究以玉米芯为原料制备水解液,对预处理及脱毒工艺进行优化,并利用高效液相色谱(HPLC)检测优化效果。结果表明,10~20目的玉米芯在10%氨水浸泡24 h后,可将乙酸和酚类物质的脱除率,分别提高至93.4%和32.3%,而糠醛的含量也大大降低。经过真空浓缩、CaO脱毒以及2%活性炭吸附后,使有毒物质含量再次降低,此时的水解液可完全用于菌株的发酵试验,达到了去除的目的。本文所得到的最佳水解液处理步骤,其结果符合菌株发酵用标准,说明水解液处理方式的不同,直接影响着水解液的制备。这为研究和利用木质纤维素等可再生资源提供了思路,也为发酵生产奠定了理论基础。  相似文献   

Arduino物联网系统在连栋大棚中的选型与设计   总被引：1，自引：0，他引：1  

张海峰  郑妍妍  张宇  李杨  苏戈  冯一新 《北方园艺》2018,(5):184-187

针对物联网技术在设施蔬菜种植研发及应用成本过高的现状,提出了一种应用于连栋蔬菜大棚的物联网系统选型及构建方案,该方案以Arduino单片机(WeMos D1)为核心,选用性价比高的传感器和开源免费的软件系统,以较低的经济成本和技术难度实现连栋大棚的空气温湿度、二氧化碳浓度、土壤含水量、光照强度的实时监测以及设施控制,为农业信息技术开发人员提供了一种新的技术解决方案。  相似文献   

A recombinant-based feline immunodeficiency virus antibody enzyme-linked immunosorbent assay.     

B Mermer  P Hillman  R Harris  T Krogmann  Q Tonelli  W Palin  P Andersen 《Veterinary immunology and immunopathology》1992,35(1-2):133-141

We have developed an antibody detection enzyme-linked immunosorbent assay (ELISA) for the identification of animals infected by feline immunodeficiency virus (FIV). The ELISA solid-phase antigen consists of recombinant FIV gag proteins expressed in bacteria. The proteins are purified from bacterial lysates as insoluble inclusion bodies. In the case of bacterially expressed p24gag, it is shown that all of the linear, sequential epitopes presented by viral p24 during infection are retained. Purified preparations can be substituted for solid-phase whole virus in the IDEXX PetChektm immunoassay. The antibody ELISA duplicates the sensitivity and specificity of the whole virus based PetChek plate assay.  相似文献   

中国旱地农业发展的对策     

葛玉梅 《农产品加工．学刊》2005,(6):44-47

分析了中国旱地基本情况和基本问题,提出了相应对策,介绍了9种旱地农业栽培技术.  相似文献   

Viral and bacterial agents associated with experimental transmission of infectious proventriculitis of broiler chickens.   总被引：1，自引：0，他引：1  

G R Huff  Q Zheng  L A Newberry  W E Huff  J M Balog  N C Rath  K S Kim  E M Martin  S C Goeke  J K Skeeles 《Avian diseases》2001,45(4):828-843

Proventriculitis of broilers can be reproduced by oral inoculation of day-old chicks with a proventricular homogenate from affected 3-wk-old broilers. The objective of the following studies was to isolate from this homogenate viral and bacterial isolates that could produce proventriculitis. A monoclonal antibody to infectious bursal disease virus (IBDV) was used to precipitate virus from the homogenate. A primary chicken digestive tract cell culture system was also used to isolate virus from a 0.2-microm filtrate of the homogenate, and a bacterium was also isolated from the homogenate. In trial 1, day-old birds were orally inoculated with either proventriculus homogenate or monoclonal antibody immunoprecipitated IBDV (MAB-IBDV). At 4, 7, 14, and 21 days postinfection (PI), 12 birds from each treatment group were subjected to necropsy. In trial 2, day-old birds were orally inoculated with either infectious proventriculus homogenate, suspect virus isolated in cell culture and propagated in embryo livers and spleens, or a bacterial isolate. Twelve birds from each treatment were subjected to necropsy at days 7, 14, 21, and 28 PI. In trial 3, treatments were maintained in negative pressure isolation chambers, and an additional treatment included virus plus bacterial isolate. Twenty-four birds from each treatment were subjected to necropsy at day 21 PI. In trial 1, infectious homogenate decreased body weight and relative gizzard weights at 4, 7, 14, and 21 days PI. Proventriculus relative weight was increased at days 7, 14, and 21 PI, and proventriculus lesion scores were increased at days 14 and 21 PI. Bursa/spleen weight ratios were decreased at day 14, and feed conversion was increased at days 4 and 21. The MAB-IBDV treatment decreased proventriculus and gizzard relative weights at day 4 PI, increased proventriculus lesion scores and bursa/spleen weight ratios at day 14, and decreased heterophil/lymphocyte ratios at day 21. In trial 2, all infected birds had significantly higher mean relative proventriculus weights at 21 days PI and had higher 4-wk mean proventriculus scores as compared with both control groups. In trial 3, birds treated with homogenate and birds treated with both suspect virus and the bacterial isolate had significantly higher proventriculus lesion scores; higher relative weights of proventriculus, gizzard, liver, and heart; lower body weights; and lower relative bursa weights compared with the saline control group. These studies suggest that infectious proventriculitis has a complex etiology involving both viral and bacterial infection.  相似文献   

In memoriam Dr Pethybridge     

H. M. Q 《European journal of plant pathology / European Foundation for Plant Pathology》1948,54(4):146-147

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Plasma triglyceride concentration during intravenous infusions of propofol and Intralipid in sheep   总被引：1，自引：0，他引：1  

B. M. Q. Weaver  D. Raptopoulos †  G. E. Staddon  W. W. Mapleson‡ 《Veterinary anaesthesia and analgesia》1996,23(1):15-19

Plasma triglyceride concentrations were measured in sheep given Intralipid or propofol, which is carried in a vehicle very similar to 10% Intralipid. A bolus dose was administered followed immediately by an infusion of the same agent for 2 h. In the animals that received propofol, the measured concentration increased by a mean amount of 3.39 mmol/l when the infusion rate was l ml/min (Group Pl) and by 7.13 mmol/l when it was 2 ml/min (Group P2). When 10% Intralipid was administered and infused at 1 ml/min (Group I10), the measured concentration increased only by 0.95 mmol/l. One hour after stopping the infusion, the excess of measured concentration over baseline had decreased in the Pl and I 10 groups to 0.52 and 0.13, respectively, of the corresponding maximum excess. The method adopted for measuring plasma triglycerides is widely used in hospitals; however, an incidental observation revealed that it is inappropriate in the presence of injections of propofol or Intralipid. Despite this, evidence and argument are presented to support the conclusion that, with propofol, plasma triglyceride concentrations increased more rapidly during the infusions and returned to baseline more slowly than with a corresponding amount of Intralipid.  相似文献