南极长城站地区土壤微生物生态作用的初步探讨

从南极长城站附近联合采样13个,并进行了土壤微生物的数量统计与种类鉴定。氨化细菌的菌量为10⁴～10⁶cells／g,共7个属：微球菌属（Micrococcus）,葡萄球菌属（Staphylococcus）,假单胞菌属（Pseudomonas）,芽孢杆菌属（Bacillus）,产碱菌属（Alcaligenes）,黄杆菌属（Flavobacterium）,节杆菌属（Arthrobacter）;固氮细菌菌量为10⁵～10⁷cells／g,仅一个固氮菌属（Azotobacter）;硝化细菌一般为10⁴cells／g,分属两个属：硝化杆菌属（Nitrobacter）,硝化球菌属（Nitrococcus）;真菌为10³cells／g,分属5个属：青霉菌属（Penicillium）,金孢霉菌属（Chrysosporium）,枝孢霉菌属（Cladosporium）,曲霉菌属（As-pergillus）,散囊菌属（Eurotium）,反硝化菌为 10²～10⁴cells／g,分属 3个属：假单胞菌属（Pseudomonas）,微球菌属（Micrococcus）,芽孢杆菌属（Bacillus）;放线菌分属3个属：链霉菌属（Streptomyces）,小单孢菌属（Micromonospora）,和诺卡氏菌属（Nocardia）。联采样品12℃培养的出现率主要类群是：假单胞菌属（42％）,芽孢杆菌属（35％）,微球菌属（31％）,节杆菌属（27％）,青霉菌属（58％）,枝孢霉菌属（54％）,硝化杆菌属（81％）,固氮菌属（88％）,反硝化细菌中主要是假单胞菌属（58％）,芽孢杆菌属（38％）。文中还讨论了微生物菌量与土壤总碳、总氮的相关性及其在该地区氮循环中的生态学作用。     

Cholesterol metabolism in copper deficient rats

The influence of copper deficiency on the appearance of newly synthesized cholesterol in the plasma lipids of rats was examined following ³H mevalonate injection. At 181 days copper deficient rats exhibited a highly significant increase in plasma cholesterol concentration. Copper deficiency was associated with a greatly enhanced appearance of ³H in newly synthesized cholesterol and cholesteryl esters in the plasma lipids. A concomitant decrease in ³H incorporation into liver lipids was also observed. The results suggest that copper deficiency markedly influences the clearance of hepatic cholesterol to the plasma pool, and a highly significant correlation was observed between plasma copper concentrations and ³H incorporation into plasma cholesterol. The results are discussed in terms of a possible role for copper in lipoprotein metabolism, bile acid metabolism, and the uptake of cholesterol by extra-hepatic tissues.     

Pain modulation by adrenergic agents and morphine as measured by three pain tests

The effects of several adrenergic agents on pain and morphine analgesia were assessed using three pain tests in rats. These tests--Tail-Flick, Hot-Plate, and Formalin--allow comparison of the effects of different noxious stimuli and different motor responses. Each pain test yielded a unique constellation of adrenergic influences, suggesting that variation of stimulus and response parameters can change the functional expression of adrenergic systems related to pain processing. The salient drug effects include: 1) a pronounced, relatively selective analgesic effect of yohimbine in the Hot-Plate test; 2) a selective analgesic effect of clonidine in the Formalin test; 3) a strikiny, but variable, antagonism of morphine analgesia by a combination of yohimbine and propranolol in the Formalin test; 4) a nonlinear dose-response curve for antagonism of morphine analgesia by propranolol in the Hot-Plate test; and 5) a generalized interference with pain responding and enhancement of morphine analgesia by most drrgs in the Formalin test. The data suggest that the type of pain test is crucial in determining the pattern of drug influences that is revealed.     

The change of the distribution pattern of the large weevil,Hyposipalus gigas Fabricius (Coleoptera,Rhynchophoridae) within a single generation. A preliminary note

The distribution pattern of adults of the large weevil, Hyposipalus gigas on logs of the Japanese black pine and that of larvae in pine stumps were examined by using the m^*−m method (Iwao , 1968). The distribution of adults on logs was contagious, probably due to their response to local heterogeneity of the environment. The larval distribution was also contagious, but there was no significant correlation between the number of larval bores and the stump size. The mortality of young larvae seemed not to be related with the number of larvae per stump, but it was related with the density per unit area of bark surface. There was some sign of inversely density-dependent or ‘all-or-none’ type mortaltiy in the late larval stage.     

Investigations in plant commonness and rarity: a comparison of seed removal patterns in the widespread Jatropha standleyi and the endemic J. chamelensis (Euphorbiaceae)

During early August to late September 1998 we examined seed dispersal in the tree species Jatropha standleyi (widespread) and J. chamelensis (endemic; Euphorbiaceae) at the Estacion de Biologia Chamela, Jalisco, Mexico. Using general linear models, we found that seed removal from beneath the parental canopy did not differ between the two species and that seed removal was correlated with both seed availability on the ground and rodent predation. We inferred that seed removal was largely mediated by rodents and determined that if a seed was not removed within 4d (approx. 16% chance), it was highly unlikely to be removed at all (approx. 3.5% chance) for both species. We note that although differences in patterns of seed removal may not explain the observed differences in range size, differences between the two species in seed crop size arc similar to patterns found in other endemic/widespread species pairs.     

Assessment of a retrofitted downstream fish bypass system for wild Atlantic salmon (<Emphasis Type="Italic">Salmo salar</Emphasis>) smolts and kelts at a hydroelectric facility on the Exploits River,Newfoundland, Canada

In 2002 and 2003, the Bishops Falls hydroelectric generating facility on the Exploits River, insular Newfoundland, Canada, underwent extensive refurbishing including replacement of turbines and installation of a ‘retrofitted’ bypass and fish handling system. The effectiveness of this new bypass system has been assessed during the annual downstream run of wild Atlantic salmon smolt and kelt in 2003 and 2004. In 2003, 195 smolt were radio tagged and released between June 9 and July 2, in the forebay of the hydro plant (19 releases) and one upstream (in-river) release. Fish guidance efficiency (FGE) of the system overall was 63% (123 of 195 fish) with 36 fish passing through the turbines, and six known mortalities. In 2004, between June 9 and July 2, a total of 358 smolt and 103 kelt were released in the forebay in 45 and 13 releases (n = 8 per release), respectively. The FGE of the system for smolt was 71.7% (257 of 358 fish) and for kelt was 92.3% (95 of 103 fish). In 2004, 96 tagged smolt passed through the turbines and 43 (44.8%) were detected at a downstream station confirming they had survived turbine passage, suggesting an overall survival of smolt passage of the Bishops Falls hydro facility in the order of 85%. A total of seven kelts (6.8%) passed through the turbines and were not detected 1.5 km downstream suggesting they did not survive turbine passage. Smolt spent on average 39.8 h in the forebay before exiting in 2003 and forebay residency averaged 26 h in 2004. In both years, most smolt selected their passage route, actively or passively, within the first 10 h with secondary peaks at 25–30 h and 50–55 h, corresponding to evening passage in the second and third night, after release. Few smolt were bypassed or entrained into turbines during daylight hours. In both years turbine passed smolt spent more time in the forebay suggesting the longer fish reside in the forebay the greater the likelihood of turbine entrainment. Kelt were either bypassed or turbine entrained relatively quickly, within 2 h of release, and virtually all kelts were bypassed/turbine entrained during the hours of 18:00 and 01:00. These data on fish behaviour and residency in the forebay will assist further refinement of operations of the bypass facility to optimize survival.     

葛洲坝水利枢纽兴建后对青、草、鲢、鳙繁殖生态效应的研究

本文分析了葛洲坝枢纽截流后,大坝上、下游草、青、鲢、鳙的繁殖条件,产卵场位置,产卵规模,鱼卵、鱼苗成色以及4种鱼的群体组成等。指出除原宜昌产卵场发生变化外,其余产卵场基本存在,并在上游新发现了几处产卵场。讨论了大坝对4种鱼的影响程度和上游存在草鱼地方性群体,论证了4种鱼不必过坝产卵的理由。