Meiofaunal responses to nutrient additions in a Mediterranean stream

1. The effects of a moderate addition of nutrients (twofold N and threefold P) were examined during a 2‐year period to determine the response to nutrient addition in a meiofaunal community inhabiting sandy patches in a Mediterranean stream. 2. The pattern of meiofaunal assemblages exhibits a high degree of intra‐ and interannual variability. This pattern alternates between periods of hydrological stability and disturbances, such as floods and droughts, which is a characteristic of Mediterranean systems. 3. A before–after–control–impact (BACI) design was used to determine the outcome of the addition by comparing an upstream non‐enriched reach with an enriched downstream reach. Analysis of the study data by means of a nonparametric permutational procedure (permanova ) showed that fertilisation had a significant effect. Density and biomass values increased in the most abundant meiofaunal groups, including microcrustaceans, oligochaetes and chironomids. Microcrustaceans were the dominant group in the permanent meiofauna. 4. We also examined differences in microcrustacean secondary production in both reaches. Ostracods and cyclopoid copepods increased their secondary production in the impacted reach as a result of the nutrient addition. 5. Our study demonstrated that moderate nutrient enrichment can affect the biomass and production of stream meiofauna, but it is still unclear whether this effect was because of autotrophic or heterotrophic pathways.     

The Ordovician-Silurian boundary stratotype: consequences of its approval by the IUGS

Lespérance, Pierre J., Barnes, Christopher R., Berry, William B. N., Boucot, Arthur J. & Mu En-zhi 1987 07 15: The Ordovician-Silurian boundary stratotype: consequences of its approval by the IUGS.
The Ordovician-Silurian stratotype at Dob's Linn, Scotland is the second systemic boundary approved by the International Union of Geological Sciences (IUGS). A review of the internationally accepted criteria required of a stratotype shows that few of these are possessed by the Dob's Linn section. The strongest attribute of the section is the presence of zonal graptolites, although the boundary is recognized primarily on a single biological event (base of acuminatus Zone) for which the evolutionary relationships of the taxa are not established. In approving this boundary proposal in 1985, which received only simple majority support within the Ordovician-Silurian Boundary Working Group (OSBWG) and which fails to meet most of the accepted prerequisites for a stratotype, the International Commission on Stratigraphy (ICS) and the IUGS have established an unfortunate precedent. It follows that future systemic boundaries need not meet the accepted standards. It raises serious questions on the assessment and voting procedures of the International Commission on Stratigraphy and on the credence accorded the recommendations developed by the International Subcommission on Stratigraphic Classification of IUGS.     

森林土壤氮转化的微生物功能研究

本文研究了不同林型下土壤(A+6层和A_1层)微生物、土壤酶活性在森林土壤氮转化中的作用。结果表明不同林型下土壤具有不同的固氮作用、反硝化作用、氨化作用和硝化作用速率,即阔叶林>针阔混交林>针叶林。已经证明,固氮作用主要存在于森林土壤的A_1层,反硝化作用主要存在于A_0层。森林土壤存在2种硝化作用过程,即由自养微生物所引起的自养硝化作用过程和异养微生物所引起的异养硝化作用过程。它的存在与林型有关,某些森林土壤中这2种硝化作用过程都存在,如针阔混交林下的A_0层和A_1层。有些林型下土壤,则以异养硝化作用过程为主,如针叶林的A_0层。     

MSI2通过下调circRNA_001214促进急性髓系白血病细胞HL60生长

Musashi-2（MSI2）是一种RNA结合蛋白质,对维持造血干细胞功能具有重要作用。研究表明,MSI2高表达能促进急性髓系白血病（acute myelocytic leukemia, AML）进展,但其作用机制尚不明确。本研究稳定沉默HL60细胞MSI2后,第1、2、3、4 d对照组的相对细胞生长率分别为1.931 ± 0.027、3.070 ± 0.073、4.017 ± 0.092和4.215 ± 0.246;敲减组分别为1.927 ± 0.035、2.564 ± 0.090、2.825 ± 0.097和3.223 ± 0.182,两组相比具有统计学差异,P<0.001;细胞凋亡明显增加(7.967% ± 0.698% vs 3.400% ± 0.322%., P<0.01);G₀/G₁期细胞比例明显增高（67.430% ± 4.390% vs. 50.360% ± 2.160%, P<0.01）;NUMB蛋白明显上调,LEF1明显下降。环状RNA（circular RNA, circRNA）芯片筛选和荧光定量PCR验证显示,MSI2沉默组circRNA_001214表达水平是对照组3.48倍。这一结果也在NALM6细胞得到证实。进一步用生物信息学分析,显示circRNA_001214最可能与miR-1273a、miR-1273e和miR 5095结合,进而影响参与细胞凋亡相关基因（CYCS、AKT1、BAX、TNFRSF10A、TNFRSF10D）、Wnt信号基因（WNT4、WNT2B、WNT7B、 DKK2、SFRP1、CSNKE1和LEF1）以及参与细胞代谢相关基因（RPE, PGAM4, PGAM1, TAT, CBS、RPE、SUCLG2、PGAM4、PGAM1和 IDNK）。总而言之,MSI2可能通过干扰circRNA_001214生成,减少靶miRNA对凋亡、Wnt信号及细胞代谢相关基因表达的影响,促进细胞生长。     

Coordinated mRNA and Protein Expression of Human LAMP-1 in Induction of Melanogenesis After UV-B Exposure and Co-Transfection of Human Tyrosinase and TRP-1 cDNAs

In order to better understand the cascade of melanogenic events in melanocytes, this report has introduced our two recent approaches for the expression of melanogenesis/or melanosome-associated genes and encoded proteins in melanocytes (melanoma cells) after repeated exposure to UV -B and after cotransfection of two human genes, i.e., tyrosinase and tyrosinase-related protein-1 (TRP-1). Repeated exposure of UV B (2.5–5.0 mJ/cm²) caused not only upregulation of tyrosinase and TRP-1 genes but also coordinated increase in the gene and protein synthesis expression of Lamp-1 (lysosome-associated membrane protein-1). When COS-7 kidney cells and amelanotic melanoma (C32 and SKMEL-24) and melanotic melanoma (G361 and SK-MEL-23) cells were exposed to cotransfection of human tyrosinase and TRP-1 cDNAs, there was also an increased expression of Lamp-1 mRNA and protein along with tyrosinase activation and new melanin synthesis. Importantly, single transfectants of human tyrosinase cDNA revealed marked cellular degeneration, whereas this degeneration was not seen in single transfectants of TRP-1 cDNA or cotransfectants of human tyrosinase and TRP-1 cDNAs, indicating that TRP-1 prevented, along with Lamp-1, programmed death of melanocytes after transfection of tyrosinase gene. The coordinated expression of TRP-1 and Lamp-1 was further confirmed by antisense oligodeoxynucleotide hybridization experiment against Lamp-1 gene, showing the decreased expression of TRP-1 as identified by three different types of anti-TRP-1 monoclonal antibodies. We propose therefore that human tyrosinase and TRP-l, when activated or expressed together, will coordinate to upregulate the mRNA expression and protein synthesis of Lamp-1. The Lamp-1 molecules will, in turn, cover the inner surface of melanosomal membrane, together with TRP-1 molecules, thus protecting the melanosomal membrane from toxic melanin intermediates generated during melanogenesis in the presence of active tyrosinase. In contrast, the expression of other lysosome-related proteins, e.g., β-galactosidase and CD63 is not stimulated in new melanogenesis.     

Upgrading the genome of an elite japonica rice variety Kongyu 131 for lodging resistance improvement

Developing a new rice variety requires tremendous efforts and years of input. To improve the defect traits of the excellent varieties becomes more cost and time efficient than breeding a completely new variety. Kongyu 131 is a high-performing japonica variety with early maturity, high yield, wide adaptability and cold resistance, but the poor-lodging resistance hinders the industrial production of Kongyu 131 in the Northeastern China. In this study, we attempted to improve the lodging resistance of Kongyu 131 from perspectives of both gene and trait. On the one hand, by QTL analysis and fine mapping we discovered the candidate gene loci. The following CRISPR/Cas9 and transgenic complementation study confirmed that Sd1 dominated the lodging resistance and favourable allele was mined for precise introduction and improvement. On the other hand, the Sd1 allelic variant was identified in Kongyu 131 by sequence alignment, then introduced another excellent allelic variation by backcrossing. Then, the two new resulting Kongyu 131 went through the field evaluation under different environments, planting densities and nitrogen fertilizer conditions. The results showed that the plant height of upgraded Kongyu 131 was 17%–26% lower than Kongyu 131 without penalty in yield. This study demonstrated a precise and targeted way to update the rice genome and upgrade the elite rice varieties by improving only a few gene defects from the perspective of breeding.     

铜对大鳞泥鳅幼鱼的毒性

本文用流水和换水式试验,在水硬度为115mg/L(以CaCO_3计)条件下研究了铜对大鳞泥鳅幼鱼生长和存活的影响。试验从刚孵出的幼鱼开始,流水式试验持续30d,换水式试验历时16d。结果表明,在流水条件下铜对泥鳅幼鱼存活有明显影响的可观察效应浓度最低是41.2μg/L,而无可观察效应浓度则为25.2μg/L。根据对现存量的影响,用换水式试验测得铜的最低可观察效应浓度为38μg/L,无可观察效应浓度是19μg/L。     

西藏色季拉山暗针叶林苔藓多样性及林窗干扰的影响

为了解西藏色季拉山暗针叶林苔藓多样性及林窗干扰的影响,在过去工作积累的基础上研究了色季拉山西坡5块样地内不同林内环境(林窗、林缘和林下)地面、腐木和树附生苔藓生物量特征。结果表明, 地面生单位面积苔藓植物生物量储量最高,平均910.10 g/m²,其次为腐木生(221.90 g/m²),树附生的最低(53.59 g/m²)。林窗地面生苔藓单位面积生物量最高,均值为360.47 g/m²,其次为林下(305.51 g/m²),最小为林缘(244.11 g/m²);林窗、林缘和林下间的地面生苔藓单位面积生物量差异显著(P＜0.05)。沿海拔梯度,林窗苔藓单位面积生物量表现出先增加后减少的趋势。因此,在西藏色季拉山暗针叶林内,林窗对地面生苔藓单位面积生物量有显著影响。     

高含量、低用量颗粒剂防治玉米螟的研究

1973—1977年,作者研究了防治玉米螟颗粒剂的“高含量、低用量”问题,即在单位面积上有效成分用量相等下,探讨逐步提高颗粒剂中有效成分含量而又按比例减少单位面积上颗粒剂用量的防治效果的相关性。结果证明,在相当大的范围内,高含量、低用量可以代替低含量、高用量。每亩用辛硫磷4克时,1.6%颗炷剂每亩用0.5斤与0.1%颗粒剂每亩用8斤均可获80%左右相似的防治效果;每亩用对硫磷40克时,8%颗粒剂每亩用1斤与1%颗粒剂每亩用8斤均可获90%以上防治效果。对地亚农和二氯苯醚菊酯试验亦获类似结果。 颗粒剂应用这一改革,有利于成品化和机械施药,并可显著降低防治成本。 同时,还做了室内毒力测定及在玉米上残效作用测定,以验证田间防治效果。 近二十年来,国内、外一直把颗粒剂做为防治玉米心叶期玉米螟(`Ostrinia nubilalis`` Hübner)的有效手段。我国自五十年代末已开始研究和应用滴滴涕、六六六等颗粒剂防治玉米螟,获得了高于六六六药液灌心的防治效果(邱式邦等,1961;邱式邦等,1963;慕立义,1963)。但由于颗粒剂用量大、费用高而未能成批生产。土法生产、群制群用的颗粒剂亦存在着缺点:(1)加工时不但造粒、选粒用工多,而且粒度、有效成分的含量及在载体上的分布均难以规格化,药效不够稳定;(2)加工所用的毒剂均为农药制剂。如用乳油、除乳化剂及有机溶剂被浪费外,往往还引起玉米的药害;如用粉剂,则不能渗入载体内部,不耐雨水冲洗而降低残效;(3)由于颗粒剂不规格化和单位面积用量大而不利于机械施药。因此,多年来生产上迫切需要高效、低毒、低残毒、价廉和利于机械施药的成品颗粒剂以代替土法生产的颗粒剂。     

Analysis of nutrient components of food for Asian elephants in the wild and in captivity

Thirty-seven wild plants as food for Asian elephants in the field in Simao, Yunnan province, China and five cultivated plants as food for captive elephants in the Beijing Zoo were collected and analyzed for their main nutrient components. Protein, fat, fiber, dry material, ash as well as major microelements: calcium, kalium, zincum, sodium in the food were analyzed by standard methodology. No significant differences were found between the wild plants taken in the field and forage provided in captivity. However, the calcium content in the forage is significantly less than the average of those in the wild plants. It is suggested that the increase in calcium intake may contribute to the relief of low plasma calcium diseases of elephants in captivity. Translated from Journal of Beijing Normal University (Natural Science), 2006, 42(2): 184–188 [译自: 北京师范大学学报 (自然科学版)]