首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
  • 1.1. Electrophysiological responses to NaCl, sucrose, and a complex mixture containing NaCl, glucose, fructose, phenylalanine and valine were obtained from large, medium, and small hair sensilla on the proboscis of the fleshfly Sarcophaga bullata.
  • 2.2. Responses from up to three cells in each sensillum were analysed and compared across the three types of sensilla.
  • 3.3. We found qualitative differences in the patterns of responses from the different hair types.
  相似文献   

2.
  • 1.1. A bioassay for octopus saliva, based on detachment of crab dactylopodite flexor muscle under standard conditions, has been developed.
  • 2.2. There is a direct relationship between increasing caseinolytic activity of saliva from Eledone cirrhosa and decreasing muscle detachment time.
  • 3.3. Fractionation of saliva, using preparative isoelectric focusing, shows that muscle releasing activity is restricted to fractions containing proteins with high isoelectric points and maximum caseinase activity.
  • 4.4. It is concluded that proteolytic enzyme(s) in octopus saliva selectively release crab muscle from attachment to the carapace.
  相似文献   

3.
  • 1.1. Unlike common fishes and as its Latin name implies, the upside-down catfish, Synodontis nigriventris, possesses dark ventral skin. Microscopic observation reveals that melanophores are present on both the ventral and the dorsal skin but differ in size and density of distribution.
  • 2.2. The darkness of both sides of the fish changes in accordance with that of the background.
  • 3.3. At night, the fish are very active and the body becomes pale. The change in color is more noticeable in the dorsal than the ventral skin.
  • 4.4. When melatonin was added to the bathing water, the fish became pale and swam restlessly even when they were exposed to the black background.
  • 5.5. It was found that the catfish preferred the black background to the white one.
  相似文献   

4.
  • 1.1. The fiber types of uropod muscles of the crayfish, Procambarus clarkii, were determined by the myofibrillar ATP-ase histochemistry and electrophysiology.
  • 2.2. The ATP-ase histochemistry was carried out on the sections of the whole tailfan and the slow muscles were identified as being of the slow type on the basis of their low staining intensities.
  • 3.3. The location of slow bundles in the mixed type muscles i.e. the dorsal rotator (DRT), the ventral rotator (VRT), and the telson-uropodalis posterior (TUP) was confirmed.
  • 4.4. TUP was newly revealed in this study to be a mixed muscle.
  相似文献   

5.
  • 1.1. A blue carotenoprotein (λmax = 634 nm) containing astaxanthin as prosthetic group, was extracted and purified from the carapace of the crayfish Astacus leptodactylus.
  • 2.2. The blue carotenoprotein contained (3S,3′S)-astaxanthin, (3R,3′S, meso)-astaxanthin and (3R,3′R)-astaxanthin in relative ratio 38:41:21.
  • 3.3. The blue carotenoprotein had an approximate mol. wt of 440,000 (gel filtration) and 437,000 (gradient gel electrophoresis).
  • 4.4. Sodium dodecyl sulphate polyacrylamide gel electrophoresis indicated the presence of two polypeptides of 19,600 and 18,600 daltons, with different mobility in polyacrylamide gel electrophoresis in the presence of 6 M urea.
  • 5.5. At low ionic strength and in the presence of denaturing agents such as SDS, urea, extreme pH and heat, the blue complex showed a greater stability than most of the carotenoproteins studied to date.
  相似文献   

6.
  • 1.1. The effects of thermal acclimatization at 10 and 24°C on heart rate were investigated on unrestrained soles (Solea vulgaris).
  • 2.2. The sensitivity of heart rate to temperature changes induced by temperature acclimatization was higher in cold-acclimatized than in warm-acclimatized soles.
  • 3.3. Heart rate of cold-acclimatized fish to temperature changes was not affected by blocking the vagal tone with atropine.
  • 4.4. After atropine treatment the ability of heart rate to show thermal compensation decreased in warm-acclimatized soles.
  • 5.5. It is suggested that the vagus nerve can function differently at different temperatures.
  相似文献   

7.
  • 1.1. Three bis(imidoesters) of different span (ca 9–11 Å) have been used to form intermolecular cross-links between the apoproteins of the lobster carapace carotenoprotein, α-crustacyanin.
  • 2.2. Dimethylpimelimidate(DMP) is the most effective of the three reagents in cross-linking the oligomeric α-crustacyanin, giving predominantly dimers between apoproteins from each of the two apoprotein classes. The native dimers, β-crustacyanins, are effectively cross-linked with this reagent.
  • 3.3. The stability of DMP cross-linked α-crustacyanin and of the native carotenoprotein to urea treatment and to heating have been compared.
  • 4.4. Reagents of longer (sulpho-N-hydroxy-succinimide ester; 18 Å) or shorter (1,5-difluoro-2,4-dinitrobenzene; 5 Å) spans than the bis(imidoesters) are similarly able to form cross-linked dimers with the crustacyanins, but less effectively under the conditions of the reactions.
  • 5.5. The results are discussed in relation to the previously presented putative structure of β-crustacyanin (Keen et al. 1990b. Eur. J. Biochem. (submitted); Zagalsky et al., 1990. Comp. Biochem. Physiol.97B, 1–18) and to an alternative subunit interface arrangement of the apoproteins for the dimer.
  相似文献   

8.
  • 1.1. The hemoglobins of Leporinus friderici were separated by liquid chromatography on DEAE-Sepharose in order to isolate the two major electrophoretic components.
  • 2.2. The chromatographic fraction I (electrophoretically slow anodic) showed no Bohr effect and no nucleoside triphosphate modulation.
  • 3.3. The chromatographic fraction III (electrophoretically fast anodic) showed a normal Bohr effect and addition of nucleoside triphosphate decreased oxygen affinity but did not alter the Bohr effect.
  • 4.4. The whole hemolysate showed a normal Bohr effect and phosphate modulation altered both Bohr effect and oxygen affinity.
  • 5.5. No or little difference between the effect of adenosine or guanosine triphosphates on hemoglobin function was observed.
  相似文献   

9.
  • 1.1. Platelets bind specifically to lactoferrin. A significant similarity between human lactoferrin and some bovine milk proteins has been established.
  • 2.2. Because of the structural homology of lactoferrin and cows milk proteins they are able to influence lactoferrins regulatory function on the level of its binding to membrane receptors on platelets.
  • 3.3. An inhibitory effect of bovine α-lactalbumin and of β-lactoglobulin on lactoferrin-receptor interaction was shown.
  • 4.4. Bovine α-lactalbumin competes with lactoferrin for the binding sites.
  • 5.5. Scatchard plot analysis of data shows one binding site for lactoferrin in the presence of α-lactalbumin with an affinity constant, Ka = 0.46 × 109 mol/1 and 335 receptors/cell.
  • 6.6. The inhibitory effect of β-lactoglobulin reaches 62% and is different for the common fraction ⨿-lactoglobulin and the genetic variants β-lactoglobulin A and B.
  • 7.7. β-lactoglobulin does not compete with lactoferrin for the membrane receptors.
  • 8.8. Bovine casein and egg lysozyme stimulate 59Fe-lactoferrin binding to the receptors. The mechanism of these effects is still unknown.
  • 9.9. Tested alimentary antigens are able to interact with lactoferrin and also with some platelet membrane structures.
  • 10.10. Established changes in lactoferrin binding to the platelet membrane might be in relation to lactoferrins regulatory function and (or) eliminating mechanisms of these alimentary antigens.
  相似文献   

10.
  • 1.1. Fundamental chitin digestion characteristics of Crassostrea virginica crystalline style were investigated.
  • 2.2. Optimum temperature and pH were 34°C and 4.8. respectively.
  • 3.3. The colloidal regenerated chitin (0.56mol/0.5 ml: GlcNAc equivalents) was saturating under all enzyme levels encountered.
  • 4.4. There was no evidence of end product inhibition, even after 100 hr incubation.
  • 5.5. Calculated Km for the chitinase complex was 1.19mM when determined using a 30 min assay, but was only 0.70 mM when determined using a 4.6 hr assay.
  • 6.6. Both Km values are lower than reported for similar assays in other molluscs and for most bacteria.
  • 7.7. Effect of substrate preparation on the kinetics are discussed.
  • 8.8. Eight peaks of chitinase activity were resolved by DEAE-Fractogel ion exchange chromatography.
  相似文献   

11.
12.
This paper comments on: Low, B. S., Alexander, R. D., and Noonan, K.M. Human hips, breast, and buttocks: Is fat deceptive? Ethology and Sociobiology 8: 249-247, 1987. In it I argue that:
  • 1.1. Sexual selection has probably not been the most important selection pressure on
  • 2.female human body shape.
  • 3.2. Male humans in different cultures find different aspects of the female body attractive
  • 4.and therefore are unlikely to have exerted consistent directional sexual selection on
  • 5.the female body.
  • 6.3. Breast size is not correlated with lactation success.
  • 7.4. Visible hip width is not correlated with parturition success.
  • 8.5. Women would lower their fitness if they tried to deceive men about their internal
  • 9.pelvic dimensions.
  • 10.6. There are many alternative hypothesis to explain the existence of fat onwomen's
  • 11.breast, hips, and buttocks.
  相似文献   

13.
  • 1.1. The medial (MGF), lateral (LGF) and motor (RMS-2) giant neurons were confirmed as neural components in the earthworm Amynthas hawayanus polysynaptic reflex circuit by simultaneous potential recording and dye injection.
  • 2.2. The reflex was initiated from the mechanoreceptors when evoked by mechanical stimulation but electrical stimulation also evoked an antidromic response in the motoneuron.
  • 3.3. The primary reflex response propagates decrementally along both giant axons but directly evoked action potentials conduct in an all-or-none fashion.
  • 4.4. The secondary reflex response continues to propagate after the primary response disappears.
  • 5.5. A rhythmically discharging neuron of uncertain function was also identified.
  相似文献   

14.
  • 1.1. The photoregulation shown by glyceraldehyde 3-phosphate dehydrogenase and glucose 6-phosphate dehydrogenase appears to be independent of the mad gene product(s) and also independent of carotene biosynthesis regulation.
  • 2.2. The photoregulation of malate dehydrogenase appeared to be dependent on the mutation of the mad and car S genes.
  • 3.3. Pyruvate kinase and lactate dehydrogenase may be classified as light-independent.
  • 4.4. The action of ATP and fructose 1,6-bisphosphate on the enzymes studied was generally independent of light/dark grown conditions.
  • 5.5. However, the effect of fructose 1,6-bisphosphate on Phycomyces pyruvate kinase appears to be light-dependent.
  相似文献   

15.
  1. Download : Download high-res image (89KB)
  2. Download : Download full-size image
Highlights
  • •The proteomes of L. lactis MG1363 and phage p2 at different stages of infection were characterized.
  • •16% (226/1412) of the bacterial proteins detected were unique to infected cultures.
  • •A targeted approach using synthetic peptides improved the coverage of phage p2 proteome.
  • •By means of proteogenomics, we uncovered a conserved phage protein coded by a previously unannotated gene.
  • •Deletion of the bacterial gene llmg_0219 (unknown function) impedes phage p2 infection.
  相似文献   

16.
Company news     
Including information on:
  • ScanSoft
  • SpeechWorks International
  • Viisage Technology
  • Firstec
  • BIO-key International
  • HP
  • ZN Vision Technologies
  • Unisys
  • US Government’s
  • Communication Intelligence Corporation
  • Infinity Technologies
  相似文献   

17.
  • 1.1. One adult male, eight pups (including two full term foetuses) and nine adult female harbour seals (Phoca vitulina) were analysed for indices of mixed function oxidase (MFO) activity.
  • 2.2. MFO activity was present in liver samples, but was at or below detection limits in samples of kidney, lung and pancreas.
  • 3.3. Hepatic ethoxyresorufin O-de-ethylase and benzo[a]pyrene hydroxylase activities were similar to those reported in other seals and in other mammals.
  • 4.4. Cytochromes P-450 and b5 concentrations were slightly lower than those observed in other mammals.
  • 5.5. MFO activities in newborn pups and foetuses were significantly lower than those in adult females.
  • 6.6. No qualitative differences in cytochrome P-450 isozyme distribution between foetal and adult samples could be discerned by electrophoresis.
  相似文献   

18.
Company news     
  • Daon
  • Musicrypt
  • EMI Music Canada
  • Digital Broadband Networks
  • FaceKey Corporation
  • Eystar Media Inc (EMI)
  • Temasya Wira
  • Animated Electronic Industries
  • BIO-key International
  • Entryport Corporation
  相似文献   

19.
  • 1.1. The lipid composition of lipophorin from the Colorado potato beetle, Leptinotarsa decemlineata Say, was analyzed.
  • 2.2. This insect lipophorin contains 44% lipid and is characterized by large amounts of hydrocarbons and small amounts of diacylglycerol.
  • 3.3. This is the first observation of a diacylglycerol-poor insect lipophorin in haemolymph.
  • 4.4. Since the main energy source for flight in the Colorado potato beetle is proline, the low diacylglycerol content in lipophorin must be related to its peculiar flight metabolism.
  • 5.5. This lipophorin, however, can still take up appreciable amounts of diacylglycerol from the locust fat body. Hydrocarbon uptake by this lipophorin was also demonstrated.
  • 6.6. The main function of this lipophorin therefore seems to be transport of hydrocarbons from oenocytes to the cuticle.
  相似文献   

20.
  • 1.1. The lipid components of three animals, the rock crab Nectocarcinus integrifons, the rock flathead Platycephalus laevigatus and the southern garfish Hyporhamphus melanochir, feeding in the seagrass beds at Corner Inlet, Victoria, Australia have been examined in detail in order to provide further information on seagrass community structure.
  • 2.2. Biological marker compounds detected within animal gut content material were used to recognize dietary sources and then utilized by community members.
  • 3.3. Both H. melanochir and N. integrifons have been shown to ingest and to varying degrees incorporate seagrass lipid material, thus further confirming the importance of seagrass carbon in the Corner Inlet environment.
  • 4.4. The southern sea garfish H. melanochir is observed to remove C18 PUFAs (polyunsaturated fatty acids) from ingested seagrass material.
  • 5.5. Seagrass sterols are altered during incorporation into the lipids of this fish.
  • 6.6. Lipid-rich digestive juices play a role in the digestive processes of all three animals.
  • 7.7. Components tentatively identified as (NMI) (non-methylene interrupted) fatty acids have been detected in the lipids of the garfish H. melanochir and the crab N. integrifons.
  • 8.8. The fecal material of all three animals represent possible sources of these lipids (NMI acids) in Corner Inlet sediments.
  • 9.9. Based on lipid compositional data, N. integrifons feeds on Posidonia australis detritus and associated epiphyte material.
  • 10.10. The removal of both plant and epibiota cellular lipids along the digestive tract of the crab was observed, although structural components such as long chain mono- and α,ω-dicarboxylic acids, which have been previously recognized as seagrass marker lipids are not directly absorbed.
  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号