OBSERVATIONS OF A VISITOR ON TIMBER DRYING IN SOUTH AFRICA

The final results are presented of a comprehensive N, P,K and dolomitic lime factorial experiment with Eucalyptus grandis planted on a fully cultivated Mispah soil series. On this marginal site, fertilising had a marked effect on the growth of E. grandis as measured at clearfelling at eight years and three months. The response to single fertiliser elements was greatest for potassium, followed by phosphorus and nitrogen, dolomitic lime having a depressive effect. The best N:P elemental fertiliser ratio was 3:1, while that for P:K was 1:3. Overall, an elemental N:P:K mixture of 3:1:3 was superior, increasing growth with rate of application. Fertilising with 100 g LAN (26% N), 100 g single superphosphate (8,3% P) and 50 g potassium chloride (50% K) increased yields at clearfelling from 56,7 t/ha for no fertiliser to 85.0 t/ha, an improvement of 49,8%. This fertiliser application is recommended for planting E. grandis on shallow soils derived from Ecca shale. Fertiliser treatments also affected form factor significantly, ranging from 0,370 to 0,411 and resulting in volume differences of 11.1% for trees with the same D.B.H. and height. Not only was the response to fertilising highly profitable in itself, but it also rendered the establishment of E. grandis to be viable on an otherwise uneconomically suitable site.     

莲雾遮光期叶片SPAD值和C、N、P、K含量的变化及其规律

对大田莲雾成年树进行遮光处理,研究遮光叶片SPAD值及C、N、P、K含量的动态变化及其规律。结果表明：叶片SPAD值受叶龄和遮光互作影响,自然条件下,叶龄40 d左右SPAD值最大,达到63.0±2.49。短时间遮光对叶片SPAD值的影响不大,遮光40 d叶片SPAD值降到最低;长时间遮光会造成叶片早衰,限制树体营养生长。遮光对叶片N、P、K、C含量均有影响,在遮光过程中,叶片的C、N、P、K含量的变化情况不尽相同,但树体对遮光后形成的弱光条件均作出响应,然后通过自身的调节,慢慢使C、N、P、K趋同于自然条件下的含量水平。莲雾叶片的碳氮比（C/N）随着遮光时间的延长而呈增大趋势,遮光40 d左右比值达到顶峰,此时是莲雾栽培上进行催花的一个关键时间点。     

不同供钾水平对茶树幼苗叶片光合作用的影响

以10月龄扦插"瑞香"茶苗[Camellia sinensis(L.)O.Kuntze cv.Ruixiang]为试验材料,通过沙培试验,设5个K浓度(0、100、200、600、2 000μmol/L),每周施肥3次,处理后24周,利用LI-6400便携式光合作用测定仪进行测定。结果表明,缺钾时茶树叶片CO2同化速率、气孔导度、水分利用率等都显著下降,而胞间CO2浓度显著增加;缺钾条件下茶树生物量、叶片钾含量、叶绿素等都显著下降。当供钾浓度为0、100μmol/L时(叶片钾含量6.63 mg/g、6.85 mg/g),茶树出现缺钾症状。     

氮磷钾配比施肥对敖汉苜蓿产量和品质的影响

摘要：采用完全随机区组设计,研究了32个氮磷钾施肥配比处理组合对赤峰地区敖汉苜蓿（Medicage sativa cv.Aohan）产量和品质的影响。结果表明,施氮肥可以显著提高苜蓿第1年的产量（P<0.05）,苜蓿产量从2.90 t·ha-1提高至3.16 t·ha-1,但施用氮肥对于紫花苜蓿第2年产量的提高幅度较小。磷肥和钾肥处理下敖汉苜蓿的产量差异显著（P<0.05）,而钾肥施入量对苜蓿产量的效果则没有氮肥与磷肥明显。施氮肥可以使苜蓿粗蛋白质含量从17.75%提高至18.74%。施磷肥和钾肥也可以提高苜蓿粗蛋白含量,磷肥处理下产量差异显著（P<0.05）,但钾肥处理下差异并不显著（P>0.05）。     

液态培养红曲霉产洛伐他汀开闭环组分的研究

对红曲霉产开环莫纳可林 K 及闭环洛伐他丁的液态发酵工艺进行研究,探讨不同培养基成分和发酵条件对产洛伐他丁开闭环组分的影响。结果表明,最佳的变温培养方法是先30℃培养2 d 后再26℃培养7 d ,产生的开环莫纳可林 K 的比例可达87％,比26℃恒温培养的提高了2.63倍。当培养基中添加8％木糖、3％蛋白胨、0.2％ NaNO3、0.2％ KH2 PO4、0.35％ MgSO4,在接种量6％,摇床转速160 r ？ min -1,采用变温培养方法,得到的洛伐他汀类物质的产量最高,且开环莫纳可林 K 含量比基本培养基的提高了18倍。     

人组织蛋白酶K在毕赤酵母中的表达、纯化及活性测定

在动物和人的骨代谢疾病中,组织蛋白酶K是木瓜蛋白酶家族中的一种半胱氨酸蛋白酶,是负责骨吸收过程中溶骨的主要关键酶,是新药物的分子作用靶点。通过毕赤酵母表达系统表达出重组组织蛋白酶K,进一步用离子交换和分子筛系统进行纯化得到高纯度有活性的重组组织蛋白酶K。运用FluStar荧光酶标仪测定390 nm(激发光)和460 nm(发射光)波长下荧光强度的变化并计算出组织蛋白酶K的酶活力为119.6 U,为进一步筛选骨质疏松等骨代谢疾病的新药提供参考。     

Effects of JNK signaling pathway on hnRNP K protein aggregates in NIH3T3 cells treated with sodium arsenite

AIM: To explore the role of JNK signaling pathway in the formation of heterogeneous nuclear ribonucleoprotein (hnRNP) K protein aggregates by observing the expression and localization of hnRNP K in NIH3T3 cells induced by sodium arsenite(NaAsO2).METHODS: The recombinant vector pcDNA3-hnRNP K-HA was constructed and transfected into NIH3T3 cells. The expression and localization of endogenous hnRNP K and distribution of the protein aggregates stimulated with NaAsO2 at different time points were observed under fluorescence microscope. The level of reactive oxygen species (ROS) in the cells was detected by a ROS assay kit. After pretreated with the inhibitors of 5 signaling pathways (JNK, MEK, PI3K/Akt, NF-κB and nuclear transport), the changes of the protein aggregates were observed.RESULTS: The recombinant plasmid was correctly constructed. The hnRNP K was mainly distributed in the nucleus. The intracellular fluorescent aggregates increased with the prolonging stimulation of NaAsO2 in the cells transfected with the recombinant plasmid, and the overexpression of hnRNP K inhibited ROS generation in the cells induced by NaAsO2. SP600125, an inhibitor of JNK signaling pathway, significantly inhibited the formation of protein aggregates. CONCLUSION: The hnRNP K is primarily located in the nucleus of NIH3T3 cells, with a small amount in the cytoplasm. The formation of protein aggregates is significant after NaAsO2 stimulation, which can restrain the level of intracellular ROS, and the process is involved in JNK signaling pathway.     

Influence of weather factors on sorghum earhead bug Calocoris angustatus Lethierry incidence

Abstract

Weather parameters during the same week and one, two, three or four weeks before were correlated with the population of earhead bug, Calocoris angustatus on different earhead stages of two hybrids, CSH 5 and K‐Tall, in main and ratoon crops. The weather factors in the different weeks contributing to the insect population varied with the stage of earhead, the hybrid and the nature of the crop (main or ratoon). In the main crop, the insect population at pre‐flowering, milky, dough and maturity stage was influenced by weather parameters one week before, the same, two and three weeks before respectively. Morning relative humidity was important in both hybrids at all stages, with a few exceptions. In the ratoon crop, the pre‐flowering and maturity stage populations were influenced by the weather parameters of the same week. The populations at milky and maturity stage were influenced by parameters four weeks and one week before the observations respectively. The factors influencing the population on CSH 5 and K‐Tall varied. In most cases morning relative humidity had a positive influence.     

Oxalic Acid Effect on Potassium Release from Typical Rice Soils of Kashmir

Batch experiments were employed to examine the influence of oxalic acid on release kinetics of potassium (K) from soils along with adsorption and desorption of soil K⁺. The soils used were three rice soils from high-, mid-, and low-altitude zones. The results showed that soil K extracted using 0.2 mol L^–1 oxalic acid was similar to that of 1 mol L^–1 boiling nitric acid (HNO₃). The relation between K release (y) and concentrations of oxalic acid (c) could be best described as y = a + b log c, whereas the best-fit kinetic equation of K release was y = a + b √t. The K release for soils was in the order Bonbagh > Ganasthan > Kreeri. An oxalic acid solution with low pH was able to release more K. Oxalic acid decreased soil K⁺ adsorption and increased desorption, the effect of which tended to be greater at lower pH.