干旱热带地区土地利用变化对土壤微生物群落组成及有机碳含量的影响

Restoration of forests poses a major challenge globally,particularly in the tropics,as the forests in these regions are more vulnerable to land-use change.We studied land-use change from natural forest (NF) to degraded forest (DF),and subsequently to either Jatropha curcas plantation (JP) or agroecosystem (AG),in the dry tropics of Uttar Pradesh,India,with respect to its impacts on soil microbial community composition as indicated by phospholipid fatty acid (PLFA) biomarkers and soil organic carbon (SOC) content.The trend of bacterial PLFAs across all land-use types was in the order:NF ＞ JP ＞ DF＞ AG.In NF,there was dominance of gram-negative bacterial (G-) PLFAs over the corresponding gram-positive bacterial (G+) PLFAs.The levels of G-PLFAs in AG and JP differed significantly from those in DF,whereas those of G+ PLFAs were relatively similar in these three land-use types.Fungal PLFAs,however,followed a different trend:NF ＞ JP ＞ DF =AG.Total PLFAs,fungal/bacterial (F/B) PLFA ratio,and SOC content followed trends similar to that of bacterial PLFAs.Across all land-use types,there were strong positive relationships between SOC content and G-,bacterial,fungal,and total microbial PLFAs and F/B PLFA ratio.Compared with bacterial PLFAs,fungal PLFAs appeared to be more responsive to land-use change.The F/B PLFA ratio,fungal PLFAs,and bacterial PLFAs explained 91％,94％,and 73％ of the variability in SOC content,respectively.The higher F/B PLFA ratio in JP favored more soil C storage,leading to faster ecosystem recovery compared to either AG or DF.The F/B PLFA ratio could be used as an early indicator of ecosystem recovery in response to disturbance,particularly in relation to land-use change.     

硬粒红皮春小麦对CGA-82725的敏感性

CGA-82725(化学名你为2-丙炔基-2-{4-[(3,5-二氯-2-吡啶基)氧基]苯氧基}丙酸酯)是一种选择性除草剂,防除阔叶作物及某些谷类作物田中多种一年生及几种多年生禾本科杂草。敏感植物主要通过其芽、茎或叶吸收。CGA-82725的药害症状首先表现为植物生长受抑,叶片褪色。     

金优晚3在区试中的表现及评价

金优晚３是由湖南杂交水稻研究中心用金２３Ａ与晚３恢复系配组而成的一个中熟优质的新组合。１９９３～１９９４年参加华联公司多点试验和全国杂交中稻早中熟组区试，表现出高产，优质，生育期适宜，适应范围广，熟期落色好，抗性好等许多优点。１在区试中的表现在全国籼型杂交中稻早中熟组区试中，１４个参试点统计，金优晚３平均亩产５４８．１７ｋｇ，居６个参试组合之首，比对照威优６４增产５．１５％。平均日产量４．４２ｋｇ，居第一。在云南蒙自点亩产７１０．８３ｋｇ，比对照增产１８．４７％，贵州遵义亩产６８７．５ｋｇ，比对…     

几种腾发量估值方法的对比研究

作者用五种方法（彭曼法，辐射法，布菜尼－克雷多法，哈格雷夫法和蒸发皿法）计算了一种参考腾发量，并对五种方法在不同气候条件下的适用性进行了研究。彭曼法被视作标准方法，其他四种方法与之相比较。尽管四种方法的估值与彭曼法的估值在量上有差别，但二者之间仍有良好的相关性。为了改正这些量上的差别，作者推导出了回归方程。对于每种气候条件，作者推荐了与之相适应的估计参考腾发量的方法。     

Oxidative degradation of triazine derivatives in aqueous medium: a radiation and photochemical study

Pulse and steady state radiolysis techniques have been used to determine the bimolecular rate constants and to investigate the spectral nature of the intermediates and the degradation induced by hydroxyl radicals ((*)OH) with 1,3,5-triazine (T), 2,4, 6-trimethoxy-1,3,5-triazine (TMT), and 2,4-dioxohexahydro-1,3, 5-triazine (DHT) in aqueous medium. A competitive kinetic method with KSCN as the (*)OH scavenger was used to determine the rate constants for the reaction of (*)OH with T, TMT, and DHT. The bimolecular rate constants are 3.4 x 10(9), 2.06 x 10(8), and 1.61 x 10(9) dm(3) mol(-)(1) s(-)(1) respectively, for T, TMT, and DHT at pH approximately 6. The transient absorption spectra obtained from the reaction of (*)OH with T, TMT, and DHT have single absorption maxima at 320, 300, and 300 nm, respectively, and were found to undergo a second-order decay. The formation of TOH(*) [C(6)OH-N(5)-yl radical], TMTOH(*) [N(5)OH-C(6)-yl radical], and DHT(*) [C(6)-yl radical] is proposed from the initial attack of (*)OH with T, TMT, and DHT, respectively. A complete degradation of TMT (10(-3) mol dm(-3)) was obtained after absorbed doses of 5 kGy in N(2)O-saturated solutions and 16 kGy in aerated solutions. A similar degradation pattern was obtained with DHT in N(2)O-saturated solutions. Complete degradation was observed with an absorbed dose of 7 kGy. On the basis of the results from both pulse and steady state radiolysis, a possible reaction mechanism involving (*)OH-mediated oxidative degradation is proposed. A complete photodecomposition of DHT was also observed in the presence of ferric perchlorate using ultraviolet light at low pH. Photoinduced electron transfer between Fe(III) and DHT in the Fe(III)-DHT complex and subsequent formation of DHT(*) are proposed to be the major processes that lead to the complete degradation of DHT at pH 3.     

Efficacy and safety of suberoylanilide hydroxamic acid (Vorinostat) in the treatment of canine corneal fibrosis

Objective Study aims were to evaluate the safety and efficacy of the Food and Drug Administration‐approved drug Vorinostat [suberoylanilide hydroxamic acid (SAHA)] in the treatment of canine corneal fibrosis using an in vitro model. Methods Healthy donor canine corneas were collected and used to generate primary canine corneal fibroblasts (CCFs) by growing cultures in minimal essential medium supplemented with 10% fetal bovine serum. Canine corneal myofibroblasts, used as a model for corneal fibrosis, were produced by growing CCF cultures in serum‐free medium containing transforming growth factor β1 (1 ng/mL). Trypan blue exclusion assays were used to determine the optimal SAHA dose for this in vitro model. Four hour after culturing with TGFβ1, CCF cultures were treated with 0.06% SAHA for 5 min (group 1) and for 24 h (group 2), representing single and multiple dose treatment regimes, respectively. Cultures were then further incubated in the presence of TGFβ1 (1 ng/μL) under serum‐free conditions until they reached 70% confluence. Trypan blue exclusion, immunocytochemistry, and TUNEL assays were used to evaluate the cytotoxicity of SAHA. Real‐time PCR, western blot analysis, and immunocytochemistry were used to determine the efficacy of SAHA to inhibit canine corneal myofibroblast formation. Results Topical SAHA application in both treatment groups successfully decreased α‐smooth muscle actin expression when compared to the TGFβ1 only treatment group (P < 0.05). Tested SAHA did not affect CCF phenotype or cellular viability and did not cause significant cell death. Conclusions Suberoylanilide hydroxamic acid safely and effectively inhibits TGFβ1‐induced CCFs transformation to myofibroblast in vitro.     

冷湿层积法对印度冷杉(Abies pindrow)和长叶云杉(Picea smithiana）种子萌发的影响

研究赤霉素(GA3),冷湿和温度 对五个种源的印度冷杉(Abies pindrow)和长叶云杉(Picea smithiana)种子萌发的影响.种子被浸泡在GA3 (10 mg(L-1)中24小时,然后在3(5(C温度的条件下冷藏15天.设计4个温度(10(C, 15(C, 20(C 和 25(C)条件来促进种子的萌发.结果表明,浸泡和冷湿处理明显增加种子的萌发率.在10 (C时种子的萌发率最高.总体结果表明,种子被浸泡在GA3 (10 mg(L-1)中24小时,冷湿藏15天,可以有效地促进印度冷杉和长叶云杉的种子萌发.统计数据表明,浸泡处理、温度和种源以及与温度的相互作用都对种子的萌发有明显的影响.     

Vaccination to control an outbreak of Mycoplasma crocodyli infection

Details of a severe outbreak of M. crocodyli infection in farmed crocodiles are reported. The outbreak was suspected to have been precipitated by translocation-related stress on the animals brought from a farm with a known history of M. crocodyli infection. Resorting to the use of an autogenous vaccine proved more effective in alleviating the disease manifestations than antibiotic therapy. Prospects of vaccination in the face of an outbreak are discussed.     

前言

湖南杂交水稻研究中心何顺武、唐传道等同志选用强恢复系明恢６３作母本，２６窄早作父本进行杂交，其Ｆ1种子用６０Ｃｏ－γ射线辐射处理。通过多代定向选育、测交筛选，于“八五”期间育成了汕优晚３、威优晚３、优Ⅰ晚３、金优晚３等系列组合，这些组合的育成与推广，正在逐步替代已应用多年、推广面积５０００万亩以上、在生产上发挥了重大作用的威优６４、汕优６４。据统计晚３系列组合１９９２～１９９５年在我国南方稻区推广面积已达１２００万亩以上，并普遍获得丰收，已成为湖南、广西、江西等省的当家组合，深受农户欢迎。晚３系…