增温与土地利用变化对青藏高原高寒草甸生态系统温室气体通量影响的研究

随着青藏高原气候变暖进程及放牧压力与开垦面积的逐年加大，非常有必要评价青藏高原高寒草甸生态系统温室气体通量对气候变暖、放牧（包括粪尿斑）和开垦的响应和反馈。与此同时，我们进行了粪尿斑及开垦对土壤理化性质影响研究。本研究对于青藏高原高寒草甸C、N循环关键过程对全球变化响应的认识具有重要意义。 本文通过2年（2006-2007）增温（白天+1.2℃，晚上+1.7℃）与放牧耦合试验，在生长季观测了增温与放牧对高寒草甸生态系统温室气体通量的影响。研究初步表明，增温试验显著增加10 cm土壤温度1℃左右；在放牧频度相对较高的2007年，放牧也显著增加了土壤温度1℃左右。总体上，增温对土壤湿度的影响不显著。 增温可以促进土壤对CH4的吸收，而放牧对CH4通量影响不大或起到一定程度抑制作用。在较低放牧频度的2006年，放牧显著降低了植物-土壤系统CO2总释放量，增温促进了CO2的释放。而在放牧频度相对较高的2007年生长季，没有发现增温及放牧对土壤-植被系统CO2释放显著的影响。2006年放牧后，增温促进了高寒草甸土壤N2O的释放；2007年，增温不放牧小区N2O总通量较对照增加了24.6%，同时放牧处理也促进了N2O释放。基于土壤温度和土壤湿度的线性回归模型可以解释55%-89%的CH4通量变异，而土壤湿度较土壤温度对CH4通量影响更大。土壤温度是影响CO2和N2O通量的主要因子，通过拟合的指数型曲线，土壤温度可以分别解释43%-63%CO2通量变异与65%-81%N2O通量变异。 在2005年与2006年夏季放牧期间，对牦牛粪尿斑处理对高寒草甸CH4、CO2和N2O通量进行了观测。牛粪小区2年观测期内CH4平均通量为687 μg m-2 h-1，而尿斑和对照土壤吸收CH4（平均通量分别为-34 μg m-2 h-1和-39 μg m-2 h-1）。牛粪小区CO2在2005年和2006年观测期内累积释放量较对照分别增加了35.8%和49.7%，而牛尿小区与对照累积释放量差异不显著。牛尿与牛粪小区N2O累积释放量显著高于对照，在2005年牛尿与牛粪小区N2O累积释放量较对照分别增加了3.7和3.5倍，而在2006年分别增加了2.1和1.8倍。因此，在估算放牧高寒草甸生态系统N2O释放时，来自牛粪斑释放量是不能被忽略的。但在中等放牧强度下（1.45头ha-1 y-1），有粪尿斑覆盖的高寒草甸在观测期内全球变暖潜势较相同面积没有粪尿斑覆盖的草甸仅增加了1%。土壤水分孔隙度（WFPS）可以解释牛尿小区35%和对照小区36%CH4通量变异。土壤温度是控制CO2释放的主要因子之一，它可以解释所有处理40-75% CO2的变异。牛尿处理（34%）、牛粪处理（48%）及对照（56%）N2O时间变异则同时受土壤温度和WFPS的驱动。在观测期内，牛尿可以显著提高土壤的pH值。粪尿斑对土壤微生物量碳氮没有产生显著性影响，但在一定时段内能显著增加土壤无机氮含量。 通过在青藏高原高寒草甸开展的人工草地试验，初步探讨了不同土地利用方式（种植燕麦、开垦后闲置及自然恢复）对CO2、CH4和N2O通量，以及土壤无机氮和微生物量氮的影响。燕麦地、自然恢复草地及开垦闲置地与天然草地相比，吸收CH4的能力均表现为增强（CH4的吸收总量分别增加了31.9%、57.2%和71.0%）。由于燕麦地生物量低于天然草地与恢复草地，造成了燕麦地土壤-植被CO2释放量低于天然草地和恢复草地。而闲置地几乎没有植被覆盖，其CO2释放量显著低于天然草地。草地恢复8年后，CO2释放基本恢复到天然草地的水平。闲置地N2O总通量显著高于天然草地，较天然草地增加了60.5%。观测期内燕麦地与天然草地相比，N2O总通量增加了24.3%，但没有达到显著性水平。开垦及种植燕麦，增加了土壤硝态氮的含量，而自然恢复地、燕麦地、天然草地和闲置地在观测期内土壤铵态氮平均含量没有观察到显著性差异。燕麦地土壤微生物量氮平均含量最低（119.7 mg N kg-1），而自然恢复草地、天然草地和闲置地土壤微生物量氮差异不大。

Studies on blackening of canned prawns. Pt. 1. Influence of copper and iron on product blackening

A linear relationship was observed between the copper content and intensity of blackening in commercially canned prawn meat. Average copper and iron contents of non-blackened canned prawn meat were 9.6 and 32.5 ppm on dry weight basis respectively. In the blackened product copper content ranged from 15.8 to 63.9 ppm and iron content between 43.7 and 71.45 ppm depending on the intensity of blackening. But incorporation of copper in the above range to experimental cans produced blackening while iron up to 250 ppm did not impart any blackening under standard conditions of canning.

Toxic effects of dimecron to fingerlings of Labeo rohita (Ham.) during acute and chronic exposures

The toxic effects of dimecron on growth, body composition and oxygen consumption of fingerlings of Labeo rohita were studied. Dimecron concentrations of 4 and 8 mg/l were used. Both acute (3-h) and chronic (15- 42 d) exposure schedules were followed. Compared with the control fish, both 4 and 8 mg/l dimecron treatment significantly suppressed weight gained in fish by 9.71% and 30% respectively during a 42 day exposure period. However, the length of fish was suppressed by 11.46% significantly only in fish group exposed to 8 mg/l dimecron. Similarly, the protein content was also significantly reduced in the above group of fish. The oxygen consumption of fish was elevated considerably, but not significantly in both group of treated fish (8.5% and 26.07%) during acute exposure. However, after 15 days of exposure the rate decreased by 18.98% significantly only in fish exposed to 8 mg/l dimecron. The threshold level of DO at low oxygen environment found to be slightly higher in fish at 8 mg/l dimecron. The survival time at the above oxygen condition was reduced during acute exposure (3-h) and that was extended during chronic (15-d) exposure.

SUB-BAND CODING TECHNIQUES FOR ROBUST 4. 8 TO 8 kb/s SPEECH CODERS.

This paper describes a speech coding technique that has been developed in order to provide a method of digitising speech at bit rates in the range 4. 8 to 8 kb/s, that is insensitive to the effects of acoustic background noise and bit errors on the digital link. The main aim has been to develop a coding scheme which provides speech quality and robustness against noise and errors that is similar to a 16000 b/s continuously variable slope delta (CVSD) coder, but which operates at half its data rate or less. A desirable aim was to keep the complexity of the coding scheme within the scope of what could reasonably be handled by current signal processing chips or by a single custom integrated circuit. Applications areas include mobile radio and small Satcomms terminals.

Aquatic ecology monitoring: water quality, fish, fish catch, sanitation and disease vectors: monitoring no. 8, 6– 10th April 2011

The result reported were from a monitoring survey no.8 undertaken between 6th and 10th April 2011 during construction period of the Bujagali Hydropwer Project (BHPP). Two pre-construction, baseline surveys in April 2000 and April 2006 were conducted and so far,durin construction phase of the project, seven monitoring surveys have been undertaken i.e. in September 2007, April 2008, April 2009,October 2009, April 2010, September 2010 and the present one, in April 2011. Since 2009 biannual monitoring surveys have been conducted at an upstream and a downstream transect of the BHPP with emphasis on the following aspects: Water quality determinants Biology and ecology of fishes and food webs Fish stock and fish catch including economic aspects of catch and Sanitation/vector studies (bilharzias and river blindness)

Results of the Austrian-Ceylonese hydrobiological mission 1970 of the Institute of Zoology of the University of Vienna (Austria) and the Department of Zoology of the University of Sri Lanka, Vidyalankara Campus, Kelaniya. Pt. 19. Aquatic and semiaquatic Hemiptera of Sri Lanka from the Austrian Indo-Pacific expedition, 1970-71

This report concerns the aquatic and semiaquatic Hemiptera collected in Sri Lanka by Prof. Starmühlner and Prof. Costa during November and December 1970. A surprising number of new species have been found in the Starmühlner-Costa material, even in groups for which comprehensive revisions exist. Seven new species are described here.

The Homology and Relationship of Human (Homo sapiens) Chromosomes 1, 19 and Dusky Langur (Trachypithacus obscurus) Chromosomes 6, 8 Demonstrated with Chromosome Painting

http://www.jstage.jst.go.jp/

Intertidal transect studies of northern Monterey Bay

In accordance with a contract dated 10/22/71 between the Association of the Monterey Bay Area Governments (AMBAG) and the University of California, Santa Cruz, (UCSC), two permanent intertidal transects with 14 permanent meter-square quadrats were established on the north shore of Monterey Bay during November, 1971. One transect (6 quadrats) was placed on the shore near the Santa Cruz Sanitation outfall, while the second (8 quadrats) was placed near the Eastcliff Sanitation District outfall at Soquel Polnt (Pleasure Point). Animals and plants within the quadrats were listed, their abundance estimated, and representative specimens collected for a reference collection maintained at UCSC. Additional species of animals and plants in the areas of the transects were collected for the reference collection. These collections will serve as a base-line for comparative studies which can follow the magnitude and direction of future changes in these areas.

Functional characterization of the human-specific (type II) form of kallikrein 8, a gene involved in learning and memory

Kallikrein 8 (KLK8) is a serine protease functioning in the central nervous system, and essential in many aspects of neuronal activities. Sequence comparison and gene expression analysis among diverse primate species identified a human-specific splice for