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1.
This paper reviews research results on food competition between a freshwater fish community and a breeding Tufted duck population. After the experimental removal of fish from the Main Lake, the following effects were observed:
相似文献
| (1) | 1. Invertebrate (chironomid and gastropod) food for ducklings and adult Tufted ducks increased substantially. |
| (2) | 2. Tufted duckling brood use of the lake increased greatly and Tufted duckling survival appears to have increased. |
| (3) | 3. Shoveler and Pochard nested successfully for the first time. |
| (4) | 4. Submerged aquatic macrophytes grew profusely over the lake bed for the first time leading directly to large increases in use of the Lake by wintering herbivorous waterfowl. |
| (5) | 5. When fish were re-introduced to the Main Lake sampling bay the increases in invertebrate abundance and, to a less marked extent, macrophyte abundance were reversed. |
2.
Victy Mercy Gerald 《Hydrobiologia》1976,49(2):103-109
| 1. | At 28°C conversion efficiency of total nitrogen (TN) was inversely related to size. |
| 2. | In the pre-adult stage protein nitrogen (PN) conversion efficiency was high whereas in the Post-adult stage non-protein nitrogen (NPN) conversion efficiency was high. |
| 3. | Lower temperature (20°C) was not congenial for PN conversion. |
| 4. | Higher temperature favoured PN conversion for smaller fish but NPN for larger fish. |
3.
Gareth Rice Roland Clift Richard Burns 《The International Journal of Life Cycle Assessment》1997,2(1):53-59
Twelve of the main European LCA software packages currently available are examined wirh the aim of establishing which are
the most appropriate for LCAs on industrial processes. The packages performances are assessed in terms of
The review concludes with a Specification Table which summarises the facilities available on each software package.
The general conclusion from this study is that for industrially based LCAs, there are four packages which may offer advantages
over the rest. These are The Boustead Model, The Ecobilan Group’s TEAM™, PEMS 3.0 and SimaPro 3.1. 相似文献
| – | • Volume of Data |
| – | • WindowsTM environment |
| – | • Network Capabilities |
| – | • Impact Assessment |
| – | • Graphical representation of the inventory results |
| – | • Sensitivity analysis |
| – | • Units |
| – | • Cost |
| – | • User Support |
| – | • Flow Diagrams |
| – | • Burdens allocation |
| – | • Transparency of data |
| – | • Input & output parameters |
| – | • Demo version |
| – | • Quality of data |
4.
| 1. | The relative abundance in Lake Bonney of the trace elements studied was BM>Fe>Cu>Ni>Mo>Co, with more than 90 per cent of each element in the monimolimnion. |
| 2. | The monimolimnion contains concentrations of B which are probably toxic to phytoplankton, and Cu concentrations which are at least potetially toxic to these organisms. |
| 3. | Concentrations of B, Cu, and Mn in the mixolimnion occassionally reach potentially toxic concentrations, but there exist mitigating influences such as high calcium levels. |
| 4. | The relative amounts of trace elements contributed by the Sollas-Lacroix meltstream to the lake were Mn>Fe>Cu>NiCo>B. Except for Co and Mo, the Sollas-Lacroix meltstream did not appear to contribute trace elements in quantities which would explain the weekly changes found in the mixolimnion. |
5.
3DFS is a 3D flexible searching system for lead discovery. Version 1.0 of 3DFS was published recently (Wang, T.; Zhou, J. J. Chem. Inf. Comput. Sci., 1998, 38, 71–77). Here version 1.2 represents a substantial improvement over version 1.0. There are six major changes in version 1.2 compared to version 1.0.
Besides the above, this paper supplies:
Supplementary material to this paper is available in electronic form at http://dx.doi.org/10.1007/s0089490050231 相似文献
| 1. | A new rule of aromatic ring recognition. |
| 2. | The inclusion of multiple-type atoms and chains in queries. |
| 3. | The inclusion of more spatial constraints, especially the directions of lone pairs. |
| 4. | The improvement of the query file format. |
| 5. | The addition of genetic search for flexible search. |
| 6. | An output option for generating MOLfiles of hits. |
| 1. | More query examples. |
| 2. | A comparison between genetic search and Powell optimization. |
| 3. | More detailed comparison between 3DFS and Chem-X. |
| 4. | A preliminary application of 3DFS to K+ channel opener studies. |
6.
Conclusions
This work was supported byKBN grant no. 7 A203 013 07. 相似文献
| (1) | The aminoesters inhibit glucose-stimulated proton extrusion by yeast cells. |
| (2) | The inhibitory activity depends on aliphatic carbon chain length. |
| (3) | The inhibition of proton extrusion is concentration-dependent. |
| (4) | The aminoesters stimulate quinacrine accumulation in vacuoles of yeast cells so they should possess affinities for lysosomes. |
7.
In the rift valley (North-East of France/South-West of Germany), the Rhine runs freely for 300 km from South to North. The absence of natural obstacles allows the development of a very regular profile of the river. We have therefore an opportunity to study very gradual modifications of the alluvial forest communities of the fluvial corridor from upstream to downstream, according to the gradual evolution of the ecological factors, related to slope decrease and hydrological modifications.We describe, from Basel to Mainz:
相似文献
| 1) | modification of dynamic processes in the forest communities such as successional sequences or sylvigenetic mosaïcs of the terminal stages. |
| 2) | modification of species richness. |
| 3) | reduction of species diversity. |
| 4) | simplification of the forest stratification. |
| 5) | modification of efficiency of the biogeochemical cycling. |
| 6) | ecological vicariances. |
| 7) | modification in species behaviour. |
8.
Victy Mercy Gerald 《Hydrobiologia》1976,49(1):77-85
| 1. | The overall rate of feeding at 28°C bears an inverse relationship to size; the time course of feeding appears to be size-independent and shows a decline with increase in time. |
| 2. | Absorption efficiency is independent of size. |
| 3. | The rates of absorption and conversion and conversion efficiency are inversely related to size. |
| 4. | The rate of feeding is reflected on the rates of absorption and conversion. |
9.
Oncostatin M, a multifunctional cytokine 总被引：6，自引：0，他引：6
10.
V. L. Sevala J. E. Steele 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1991,161(4):349-355
Glycolytic intermediates and related metabolites were measured in the fat body of the American cockroach (Periplaneta americana) to locate the rate-limiting reactions that regulate glycolysis during the action of the corpus cardiacum (CC) in vitro.
相似文献
| 1. | The concentrations of glucose 1-phosphate, fructose 6-phosphate, and fructose 1,6-bisphosphate were approximately doubled after 30 min treatment with CC extract, whereas that of glucose 6-phosphate increased more than four-fold. Slightly lower increases occurred after 10 and 60 min treatment. |
| 2. | Triose phosphates, 2-phosphoglyceric acid, phosphoenolpyruvate and pyruvate were unaffected by CC extract. |
| 3. | Glycerol 3-phosphate, which is 20\2-200 times more concentrated than any of the other measured metabolites in the unstimulated tissue, is increased more than two-fold by CC extract. |
| 4. | NAD, NADP, and ATP were not significantly affected by CC extract. ADP was increased significantly by the gland extract. |
11.
Culture studies with healthy and virus-infected isolates of Ectocarpus siliculosus, Feldmannia simplex and F. irregularis gave the following results:
相似文献
| – | Virus particles are produced in deformed reproductive organs (sporangia or gametangia) of the hosts and are released into the surrounding seawater. |
| – | Their infective potential is lost after several days of storage under laboratory conditions. |
| – | New infections occur when gametes or spores of the host get in contact with virus particles. The virus genome enters all cells of the developing new plant via mitosis. |
| – | Virus expression is variable, and in many cases the viability of the host is not impaired. Infected host plants may be partly fertile and pass the infection to their daughter plants. |
| – | Meiosis of the host can eliminate the virus genome and generate healthy progeny. |
| – | The genome of the Ectocarpus virus consists of dsDNA. Meiotic segregation patterns suggest an intimate association between virus genome and host chromosomes. |
| – | An extra-generic host range has been demonstrated for the Ectocarpus virus. |
| – | Field observations suggest that virus infections in ectocarpalean algae occur on all coasts of the world, and many or all Ectocarpus and Feldmannia populations are subject to contact with virus genomes. |
12.
13.
Morten Buhl Jørgensen Barbara Schmitz Jakob Christensen-Dalsgaard 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1991,168(2):223-232
| 1. | We used laser vibrometry and free field sound stimulation to study the frequency responses of the eardrum and the lateral body wall of awake male Eleutherodactylus coqui. |
| 2. | The eardrum snowed one of two distinct frequency responses depending on whether the glottis was open (GO response) or closed (GC response) during the measurement. |
| 3. | The lateral body wall vibrated with a maximum amplitude close to that of the eardrum and in the same frequency range. |
| 4. | Covering the frog's body wall with vaseline reduced the vibration amplitude of the GC response by up to 15 dB. |
| 5. | When a closed sound delivery system was used to stimulate a local area of the body wall the eardrum also showed one of two types of responses. |
| 6. | These results suggest that sound is transmitted via the lung cavity to the internal surface of the eardrum. This lung input has a significant influence on the vibrations of the eardrum even when the glottis is closed. |
| 7. | The vibration amplitude of the eardrum changed with the angle of sound incidence. The directionality was most pronounced in a narrow frequency range between the two main frequencies of the conspecific advertisement call. |
14.
Yasuo Nakaoka 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1989,165(5):637-641
| 1. | Paramecium bursaria was stimulated by a light spot of 10–15 m diameter, and the photosensitive site was searched by recording responses in swimming behavior and in membrane potential. |
| 2. | Local stimulation to the anterior half of the cell caused an avoiding response. |
| 3. | Stimulation to the cells deciliated by ethanol treatment elicited a depolarization of the membrane potential. |
| 4. | Local stimulation to the anteroventral portion elicited a depolarization, but stimulation to the dorsal side induced no change in the membrane potential. |
| 5. | The action spectrum of depolarization elicited by local stimulation to the anteroventral surface showed two main peaks at 420 nm and 560 nm, corresponding to those of light stimulation of the whole cell. |
| 6. | It is concluded that a photosensitive site exists on the anteroventral surface ofParamecium, in particular within the oral groove of the cell. This local photosensitivity is discussed with respect to the mating reaction. |
15.
Being able to carry zidovudine (AZT) at known concentrations into CD4+/CD38+ and CD14+ cells permits:
Further studies are necessary in order to:
相似文献
| – | - to reduce the drug dosage and to increase the interval for administration (until 1 dose I.V. every week); |
| – | - to modulate the drug concentration into the CD4+/CD38 an CD14+ cells in relation to the in vitro determined HIV sensitiveness; |
| – | - to eliminate haematological, medullary and general toxicity; |
| – | - to be able to treat severely hill patients. |
| – | - To find out the better phase to start the therapy; |
| – | - To use several drugs with different mechanisms of action in order to slow down as much as possible the presence of resistant viral strains. |
| – | - As for other drugs which are beginning to be used with artificial vehicles, futher studies are required to improve the selectivity and safety of LIPOAZT for the target cells including macrophages. |
16.
Cannibalism in teleost fish 总被引：1，自引：0，他引：1
| 1. | Cannibalistic behaviour in fish is reviewed here for the first time. |
| 2. | Cannibalism has been recorded in 36 out of 410 teleost families according to the published literature, but is considered to be more widespread than this. Finding examples of cannibalism is not difficult, and it may be more interesting to look for taxa in which the behaviour does not take place. |
| 3. | The families that have provided the most information include the Engraulididae, Esocidae, Poeciliidae, Gasterosteidae, Percidae and Cichlidae. |
| 4. | Cannibalism has been classified into seven types, depending on life-history stage, age difference between cannibal and prey, and whether or not they are related. |
| 5. | Although in captive populations, cannibalism tends to increase with increasing density and decreasing food availability, its role in population regulation has not been unequivocally demonstrated in any wild population, and obtaining the necessary data presents a formidable challenge to fish ecologists. |
| 6. | Cannibalism is of some economic importance in aquaculture, but its impact can be reduced relatively easily, by frequent grading to reduce size variability. |
| 7. | The main proximate advantage conferred by cannibalism is assumed to be nutritional. In an ultimate sense the behaviour may have evolved as a particularly effective competitive strategy. |
| 8. | Finally, it is considered that cannibalism deserves more attention from fish biologists. Investigations, however, should recognize the different types of cannibalistic interaction, and, in particular, should explore the different implications of kin and nonkin cannibalism |
17.
John C. Montgomery John A. Macdonald Gary D. Housley 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1988,163(6):827-833
| 1. | Non-visual sensory systems are likely to be important in antarctic fish since these fish inhabit an area where low light levels occur for long periods. This study was undertaken to examine the suitability of the lateral line system for prey detection. |
| 2. | Recordings were made from afferent fibres of the anterior lateral line in the antarctic fishPagothenia borchgrevinki. |
| 3. | A vibrating probe was used to stimulate the lateral line at a range of frequencies between 10 and 100 Hz. |
| 4. | Most units responded best at a stimulus frequency of 40 Hz. Below the best frequency the response typically declined steeply and at higher frequencies it was usually better sustained. |
| 5. | Crustacea identified as major components of the diet ofPagothenia borchgrevinki were individually attached to a force transducer to determine the vibrations produced by swimming movements. |
| 6. | The Fourier amplitude spectra of swimming crustaceans exhibited prominent low frequency peaks at 3–6 Hz and higher frequency peaks in the 30–40 Hz range. |
| 7. | It is concluded that the overlap in the frequency response characteristics of the anterior lateral line and the frequencies produced by crustacean prey clearly establishes the suitability of the lateral line for prey detection. |
| 8. | In several instances recordings were made from fish primary afferent neurons responding to a swimming amphipod. These recordings confirm that crustacean swimming is indeed a potent natural stimulus of the lateral line system. |
18.
J. Robb 《Human Evolution》1994,9(3):215-229
In recent years anthropologists have made much progress in understanding ancient activities from skeletal remains. In this
paper, material from the Iron Age cemetery at Pontecagnano (VII-IV century BC) is used to illustrate activity-related traits
of eight basic categories:
These traits, and others, can be used not only singly but in conjunction to define (a) patterns of activity and occupational
specialization for individuals, and (b) distributions within society reflecting the basic division of labor by geneder and
class. 相似文献
| (1) | idiosyncratic patterns of dental wear |
| (2) | activity-related articular degeneration |
| (3) | non-pathological functional alterations (neoformations, contact facets) |
| (4) | mechanical remodelling of bone architecture |
| (5) | enthesopathies (muscular lesions) |
| (6) | traumatic lesions |
| (7) | activity-related pathologies |
| (8) | activity-related nutritional characteristics |
19.
Gustaaf M. Hallegraeff 《Aquatic Ecology》1976,10(2):87-95
| 1. | Spectrophotometric and paper chromatographic analyses have been made of pigments in the summer phytoplankton of eight lakes that widely differ in trophic characteristics. |
| 2. | A comparison has been made between Margalef's pigment ratio, the carotenoid/chlorophyll-a ratio, the pigment diversity expressed as the number of coloured spots on a paper chromatogram, and the pigment diversity calculated by using the Shannon formula. |
| 3. | No evidence has been found for an increase of diversity of phytoplankton pigments along a gradient from eutrophic towards oligotrophic lakes. |
| 4. | Pigment diversity cannot be simply used as a measure of lake maturity according to Margalef's ideas. |
20.
Phytoplanktonic populations were studied in Tazenat lake by three methods:
A comparison of the results obtained gives an insight into the utilisation and transformation of energy by the biota of the lake 相似文献
| – | Primary production using 14C technic |
| – | Standing crop estimation |
| – | Amount of chlorophyll a |