Adaptations of an Emergence Trap for Use in Tropical Streams

An emergence trap based on the MPI Schlitz model was designed for use in the tropics and it was tested over one year in Palawan, the Philippines. Instructions for construction and use are given here. Only commonly available materials were used, except for the collection assembly made of UV‐light permeable acrylic glass. Heavy and bulky assemblies were avoided to enable easy transportation in the field. A special modification allows a fast and easy replacement of the screen when damaged by flooding, as is often required when traps are used downstream of headwaters. This type of trap also allows sampling of a wide littoral strip. Problems concerning the use of emergence traps in the humid tropics are discussed based on experience at different longitudinal stream sections in Palawan. The results presented here suggest that this trap should be used especially for qualitative or semi‐quantitative approaches. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

L-肉碱生物合成降解途径及生产方法

Ｌ－肉碱现已广泛应用于医疗、保健、食品等领域,效果显著。高等动物不能降解Ｌ－肉碱,而许多微生物能降解Ｌ－肉碱,其途径可划分为三类,分别以大肠杆菌、不动杆菌及假单胞菌为代表。目前,有关开发Ｌ－肉碱的研究报道很多,其中主要还是两大类：化学合成及生物转化,其中生物转化的方法被普遍看好。对Ｌ－肉碱在生物体内代谢途径认识的加深以及基因工程技术在改良菌株上的应用,将进一步促进Ｌ－肉碱的大规模工业化生产。     

Isolation of dsRNA-associated VLPs from the strain Cryptococcus hungaricus CBS 6569

Double-stranded RNAs (dsRNAs) with molecular masses 1.7 and 5.0 kbp, respectively, were isolated from the strain Cryptococcus hungaricus CBS 6569. The dsRNAs were copurified with eicosahedric virus-like particles, 29 nm in diameter. This strain produced a protease-sensitive `toxin' which inhibited the growth of strain C. hungaricus CBS 4214. The toxin had maximum activity at pH 3.7. The highest toxin amount was attained after a culture period of four days.     

Insectivore life histories: further evidence against an optimum body size for mammals

1. This study tests a model of the relationship of body mass to reproductive power (the rate of conversion of energy from the environment to an organism's offspring). Specifically tested is the prediction that the regression of life-history variables on body size will change slope and sign about an 'optimum' body mass of 100 g.
2. Life-history data from the mammalian order Insectivora have been collated and analysed using a phylogenetic comparative method to test this prediction.
3. The analyses showed little evidence for significant changes in slope or sign around 100g body mass, or other possible optimal body masses, contradicting the predictions of the model. These findings agree with those of similar analyses on life-history variables of bats.     

The track structures of ionizing particles and their application to radiation biophysics

A new approach to the interpretation of the effects of radiation on cells is described, in which sample particle tracks are constructed using a Monte Carlo computer program and the exposure of cellular targets to these tracks is simulated using a second program known as BIOPHYS. Data on the shapes and DNA contents of the cell nuclei are obtained from the literature. It is assumed that the sensitive material is DNA, and that the target is divided into cubes of approximately 2 nm (the diameter of the DNA helix) per side; the numbers of these cubes containing different numbers of ionizations are derived. Two different methods of analysing the output of BIOPHYS are described. In the first, it is assumed that lethality is caused by the occurrence of a number of ionizations equal to or greater than a certain threshold in one cube; in the second method, it is assumed that only two ionizations are required, in different parts of the cube, but that only some fraction of the cube is sensitive. These models have been applied to the interpretation of the variation of radiosensitivity with a linear energy transfer (LET) of spores of Bacillus subtilis exposed wet and dry, and good fits to the published experimental data were obtained using both models. Fits to experimental data for a range of other cell lines will be presented in a second paper. Received: 5 August 1998 / Accepted in revised form: 28 April 1999     

Colour-coded sampling: the pan trap colour preferences of oligolectic and nonoligolectic bees associated with a vernal pool plant

1. Pan traps or water traps have been used widely to sample agricultural insect pests, but no formal studies have assessed the utility of these traps as sampling devices for bees. 2. Coloured pan traps, used as flower models, can efficiently and selectively sample an oligolectic bee, Andrena (Hesperandrena) limnanthis, and other bees associated with white-flowered Limnanthes douglasii rosea. 3. Females and males of A. limnanthis unexpectedly exhibit different colour preferences. Females are strongly attracted to white and blue traps, but discriminate against yellow traps. Males prefer white traps over blue and yellow traps. Consequently, blue traps are selective for females only, while white traps are selective for both sexes. 4. Non-A. limnanthis bees were caught in significantly greater numbers in yellow than in blue or white traps. These bees included generalists, as well as specialists that are oligolectic on mostly yellow-flowered species. 5. Colour of traps had a significant effect on the numbers of A. limnanthis females and males, and non-A. limnanthis bees caught in traps. These results indicate that quantitative sampling of bees by pan trap methods can be highly sensitive to trap colour.     

黄酒中酒液粒度与混浊沉淀的关系

对煎酒前后酒液品质进行了分析,并应用９０°光散射实验考查煎酒前后,储存阶段酒液平均粒度和酒液沉淀物的平均粒度,发现酒液中沉淀物的出现和酒液平均粒径的一定大小存在耦合,当酒液平均径达到一定水平,沉淀过程就逐渐开始。     

一种处理人体骨骼肌肉层各向异性导电性的数值方法

重点讨论了应用电磁场数值计算方法求解心电图正问题和逆问题中人体骨骼肌肉层的各向异性导电性的处理方法．文中应用有限元和边界元结合的方法,构造了一个包含不同的纤维方向组合的骨骼肌肉层的三维胸腔模型,并在此模型下引入了局部坐标内的各向异性导电率向整体坐标转换的方法．据此进行的模拟计算结果以图像的方式清晰地展示了各向异性导电性对体表电位图的影响．     

质量—数量性状遗传参数估计的P1,P2,F1,B1,B2联合分析方法

提出利用亲本Ｐ_１和Ｐ_２、杂种Ｆ_１、回交Ｂ_１和Ｂ_１五个世代联合分析包括两个位点主基因控制的质量－数量性状遗传的统计方法,共建立了可供选择的微基因遗传、一对主基因＋微基因混合遗传、二对主基因＋微基因混合遗传三类五种（套）共 ２８个遗传模型,采用 ＡＩＣ信息准则选择最适模型,并通过适合性检验对所选择的遗传模型做进一步的检验．文章最后还讨论了两种变型设计．     

观察导管和筛管的两种简便方法

采用将徒手切片煮沸透明的方法改进了两种观察导管和筛管的方法