岩溶地区开凿隧道对地下水循环系统的破坏--以重庆市中梁山为例

中梁山岩溶槽谷区地下水循环系统可明显的分为上层溶隙水循环带、溶隙潜水循环带和深层溶隙水渗透带.其中溶隙潜水循环带是主要的水资源储水带,深层溶隙水渗透带是深层地下水或承压水的补给系统.人工开凿交通隧道和采煤隧洞破坏了地下水的循环系统,加大了深层溶隙水的排泄量,引起了岩溶地区地下水水源的枯竭.     

Development of ITS sequence based SCAR markers for discrimination of Paphiopedilum armeniacum, Paphiopedilum micranthum, Paphiopedilum delenatii and their hybrids

Paphiopedilum armeniacum, Paphiopedilum micranthum and Paphiopedilum delenatii are endangered orchid species. These three Paphiopedilum species and their hybrids are difficult to distinguish morphologically. In this study, rDNA-ITS (internal transcribed spacer) sequences were used to design species-specific SCAR (sequence characterized amplified regions) markers to distinguish P. armeniacum, P. micranthum, P. delenatii and their respective hybrids. The developed markers efficiently amplified 600 bp DNA product for P. armeniacum and its hybrids (SCAR-600armF/Pap-ITS2R), 300 bp product for P. delenatii and its hybrids (SCAR-300delF/Pap-ITS2R) and 700 bp product for P. micranthum and its hybrids (SCAR-700micF/Pap-ITS2R). The effectiveness of designed species-specific markers was also confirmed by using multiplex polymerase chain reaction amplification with a combination of developed three SCAR markers.     

浅析野燕麦草对洛隆县主要农作物的危害及防治措施

野燕麦（Avena fatual）西藏群众俗称“跃布”，在西藏分布很广。是西藏高原农区最主要的一种杂草。由于其在西藏高原适应性强，繁殖极快，已成为一种难以除尽的团间恶性杂草．在海拨2400-4500米农区普遍存在。我地区以洛隆、边坝两县为野燕麦高发区。     

Antimicrobial susceptibility and plasmid analysis of Actinobacillus pleuropneumoniae isolated in Taiwan.

Sixty Actinobacillus pleuropneumoniae (App) strains from pigs in Taiwan were examined. Serotyping revealed that these belonged to serovars 1 (n=53), 2 (n=3), and 5 (n=4). Agar disk diffusion susceptibility testing of the isolates showed 55 (92%) were resistant to three or more antimicrobial agents. Six resistance patterns were observed. Ampicillin-chloramphenicol-flumequine-nalidixic acid-streptomycin-sulfonamide/trimethoprim-tetracycline was the most common multi-resistance pattern. Minimal inhibitory concentration of 14 antimicrobial agents was determined. The isolates were highly susceptible to ceftiofur and trimethoprim in vitro. Isolates were resistant to streptomycin, ampicillin, and nalidixic acid. All isolates were examined for the presence of plasmids using the alkaline lysis method. Forty three (72%) isolates had four plasmid bands with an approximate sizes of 3.5, 4.3, 5.8 and 6.0 kb; 12 (20%) had three bands at 3.5, 4.3 and 5.2 kb, and 5 (8%) had no plasmid bands. Antimicrobial resistance plasmids were detected in resistant strains of App. Three antimicrobial resistance plasmids were transformed into E. coli DH5 alpha. pTMY1 (4.3 kb) encoded a streptomycin kinase and a dihydropteroate synthase; pTMY2 (6.0 kb) encoded ROB-1 beta-lactamase and aminoglycoside 3'-phosphotransferase; pTMY3 (5.2 kb) encoded only ROB-1 beta-lactamase. The 4.3 kb plasmid was sequenced and consisted of 4242 bp with 42.9% GC content. The 4.3 kb plasmid DNA sequence was 98% homologous to a plasmid previously isolated from Pasteurella haemolytica.     

Cell-mediated immune response of goldfish, Carassiusaurafus (L.), to Ichthyophthirius multifiliis

Goldfish, Carassius auratus (L.), were intraperitoneally injected with two doses of Ichthyophthirius multifiliis (each containing 2.3 × 10⁶ live tomites) in saline, 30 days apart. The control fish were injected with saline only. Two weeks after the last vaccination, fish of both groups were intradermally injected with 2.5 × 10⁵ live tomites for skin tests. The skin at the antigen-injected site of the vaccinated fish increased in thickness from 8 h onwards and reached a peak at 24 h. Histological study showed a heavy infiltration of mononuclear leucocytes at the antigen-injected site. In contrast, no such changes were encountered in control fish. The migration area of pronephros cells from the vaccinated fish was significantly inhibited, in vitro, compared to controls with the presence of antigens. These findings suggest that the tomite-vaccinated fish produced a cell-mediated immune response. However, vaccinated fish also exhibited significantly higher titres of immobilizing antibodies in their sera and mucus than the controls. Therefore, it is likely that both humoral and cell-mediated immune responses have to work closely together to eliminate the infectious tomites of I. multifiliis which succeed in penetrating the fish epithelial tissues.     

Isolation and characterization of fish Aeromonas hydrophila adhesins important for in vitro epithelial cell invasion

The molecular mechanisms involved in the invasion of Aeromonas hydrophila (strain PPD 134/91) into host cells were studied in vitro using a carp epithelial cell line. Bacterial fractions were extracted with potassium thiocyanate (KSCN) to investigate the adhesins involved. Two groups of adhesins were found. The major group was high molecular weight proteins with the largest component being a 43-kDa protein. Amino terminal sequence analysis indicated that this may have been an outer membrane porin. This supports previous suggestions that a 43-kDa outer membrane protein may be important in adhesion of a human isolate of A. hydrophila . The minor group of adhesins were low molecular weight proteins likely to be less effective in mediating bacterial adhesion and invasion into carp epithelial cells.     

Conservation management of common dolphins: Lessons learned from the North-East Atlantic

1. The short-beaked common dolphin is one of the most numerous cetacean species in the North-East Atlantic and plays a key functional role within the ecosystem as a top predator. However, in 2013, its conservation status for the European Marine Atlantic, under Article 17 of the Habitats Directive, was assessed as ‘Unfavourable-Inadequate’. Of key concern for this species is fishery bycatch, with pollution also being an issue. There are, however, major knowledge gaps concerning the extent of the effects of such pressures on the species.
2. Implementation of national observer bycatch programmes and bycatch mitigation measures under EC Regulation 812/2004 has been important. The responsibility for this is currently being transferred to the EU fisheries Data Collection Framework and Technical Measures Framework, the potential advantages and disadvantages of which are discussed. Collection of data and samples through national stranding schemes in some countries has enabled assessments of life-history parameters, dietary requirements, and the effects of stressors such as pollutants.
3. Nevertheless, in order to improve the conservation status of the North-East Atlantic population, a number of key actions are still required. These include the implementation of a species action plan, finalization of a management framework procedure for bycatch, and coordination between member states of monitoring programmes. It is important that there is monitoring of the state of the common dolphin population in the North-East Atlantic management unit through regular surveys spanning the range of the management unit, as well as continued assessment of the independent and interactive effects of multiple stressors. Above all, conservation status would be improved through application and enforcement of existing legislation in European waters.
4. This paper provides a summary of the current state of our knowledge of common dolphins in the North-East Atlantic along with recommendations for conservation management that may also be relevant to the species in the Mediterranean Sea.

     

宁夏六盘山华山松树干液流的动态研究

为了解华山松树干的液流特征及其对微气象因素的响应,2008年5月～10月份,在宁夏六盘山应用热扩散液流探针测定了华山松树干的液流速率,并同步监测了气象因子.华山松树干液流速率呈现出明显的季节变化规律:生长季前期(5月、6月)随着气温回升华山松树干液流速率迅速增加;生长季中期(7月、8月)树干液流速率达到整个观测期的蜂值(0.201 3ml/cm2/min、0.177 3 ml/cm2/min);生长季后期(9月、10月)树干液流速率受生理调节影响明显降低,到10月初中旬液流速率已经降至很低(0.033 2ml/cm2/min).华山松瞬时树干液流速率主要受饱和水汽压差的影响(R=0.933),而日均液流速率则主要受太阳辐射的影响(R=0.582).     

The Cytoprotective Effect of Petalonia binghamiae Methanol Extract against Oxidative Stress in C2C12 Myoblasts: Mediation by Upregulation of Heme Oxygenase-1 and Nuclear Factor-Erythroid 2 Related Factor 2

This study was designed to examine the protective effects of the marine brown algae Petalonia binghamiae against oxidative stress-induced cellular damage and to elucidate the underlying mechanisms. P. binghamiae methanol extract (PBME) prevented hydrogen peroxide (H₂O₂)-induced growth inhibition and exhibited scavenging activity against intracellular reactive oxygen species (ROS) induced by H₂O₂ in mouse-derived C2C12 myoblasts. PBME also significantly attenuated H₂O₂-induced comet tail formation in a comet assay, histone γH2A.X phosphorylation, and annexin V-positive cells, suggesting that PBME prevented H₂O₂-induced cellular DNA damage and apoptotic cell death. Furthermore, PBME increased the levels of heme oxygenase-1 (HO-1), a potent antioxidant enzyme, associated with the induction of nuclear factor-erythroid 2 related factor 2 (Nrf2). However, zinc protoporphyrin IX, a HO-1 competitive inhibitor, significantly abolished the protective effects of PBME on H₂O₂-induced ROS generation, growth inhibition, and apoptosis. Collectively, these results demonstrate that PBME augments the antioxidant defense capacity through activation of the Nrf2/HO-1 pathway.     

The effect of conglutinin on production of reactive oxygen species in bovine granulocytes

Conglutinin is a high molecular-weight lectin originally detected in bovine serum. It belongs to the family of collectins that bind sugar residues in a Ca²⁺-dependent manner and are effector molecules in innate immunity. Conglutinin appears to play an important role in immune defense mechanisms, showing antiviral and antibacterial activities when tested in vivo and in vitro. The present study evaluated the effect of conglutinin on the respiratory bursts in bovine peripheral phagocytes. Using nitroblue tetrazolium and hydrogen peroxide assays, we showed that sugar ligand-bound conglutinin stimulated the production of superoxide and H₂O₂ in granulocytes whereas the non-sugar-bound form of conglutinin inhibited these processes. These results indicate that both forms of conglutinin are able to interact with surface leukocyte receptors but have opposite effects on phagocytic activity. Our findings suggest that conglutinin bound to sugar residues on microbial surfaces can induce oxygen burst in phagocytes, and thereby mediates the elimination of pathogens and prevents the spread of infection.