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1.
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. |
2.
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 |
3.
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. |
4.
Jiří Doskočil 《Molecular and cellular biochemistry》1976,10(3):137-143
| (1) | The inactivation of various forms of nucleoside transport with reagents blocking thiol groups was studied in whole cells ofE. coli B. No positive correlation between the efficiency of active transport and the extent or rate of inactivation could be demonstrated. |
| (2) | The most efficient constitutive nucleoside-transporting system was found to comprise a specific thiol component characterized by low rate of inactivation with N-ethylmaleimide; the less efficient inducible transport and the facilitated diffusion of guanosine require the integrity of another thiol component which is rapidly inactivated with N-ethylmaleimide. |
| (3) | The constitutive nucleoside-transporting system is completely inactivated with T4 phage, while other modes of nucleoside transport are much less affected. |
| (4) | Inactivation of constitutive transporting system in cells exposed to N-ethylmaleimide for a limited period of time continues long after the inhibitor has been removed, indicating storage of the inhibitor in some cellular compartment. Addition of dithiothreitol stops the inactivation immediately. |
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.
Ueda Junichi Miyamoto Kensuke Saniewski Marian Hoshino Tomoki Utsunomiya Maki Okubo Hiroshi 《Acta Physiologiae Plantarum》2002,24(2):187-194
Methyl jasmonate (JA-Me) promoted leaf abscission of succulent plant, Crassula lycopodioides, and exudation from stems and leaves after leaf abscission when it was sprayed in whole plants. Major component of the exudate
was identified as sucrose based on the results described below.
In addition, potassium and sodium were found in the exudate as major inorganic cations. These results suggest that exudate
of Crassula lycopodioides is phloem sap, and JA-Me promotes the excudation due to the inhibition of the synthesis of callose in sieve tubes of succulent
plants. 相似文献
| (1) | The reaction of the excudate was not positive in the Somogyi-Nelson method but in the phenol-sulfuric acid method. |
| (2) | The exudate was hydrolyzed with invertase of Candida utilis, after that showing a positive reaction in the Somogyi-Nelson method. |
| (3) | Only glucose and mannose were identified in the exudate after hydrolysis with trifluoroacetic acid using a gas-liquid chromatograph (GLC). |
| (4) | A single peak corresponding to the retention time of sucrose was observed using a high performance liquid chromatograph (HPLC). |
7.
P. Torkkeli M. Weckström E. Kouvalainen M. Järvilehto 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1989,165(3):333-341
| 1. | We have discovered a previously unreported visual mutant of the blowfly,Calliphora erythrocephala. It shows a reduced or absent visual performance, e.g., in escape and optomotor behavior. The effects of this mutation on the ultrastructure were studied by electron microscopy (Figs. 3–8) and on electrophysiological function, by intracellular recordings (Figs. 1 and 2). |
| 2. | The genetic basis of this spontaneous mutation was studied by test crosses of mutant and wild-type flies. The defect appears to be in an autosomal recessive gene (Table 1). |
| 3. | Of the mutant stock studied soon after eclosion (n = 18) 35% shows optomotor reactions, whereas only 6% studied in later life (n = 240) shows any optomotor behavior. |
| 4. | The absence of the receptor potentials in photoreceptor cells is not directly associated with structural disorders in the early life of these mutant flies, but several types of degenerative changes are manifested in the retinular cells later on. The optomotorically blind specimens have normal (about –60 mV) resting membrane voltages but no detectable receptor cell voltage response to light, indicating a block in phototransduction. The spectral and polarization sensitivities of optomotor-positive flies are normal (Fig. 2). |
| 5. | At the beginning of degeneration the number of lysosomes in the receptor cells is increased compared with normal flies, but their number as well as that of other components of the cell interior decrease later on. During the progression of the degeneration, the rhabdomeres shrink while the mitochondria swell and disintegrate (Figs. 6–8). |
| 6. | The blocking of phototransduction is proposed to lead to disturbance of the turnover of the rhabdomeres and finally to degeneration of the receptor cells. |
8.
Wang Yusheng 《Plant Ecology》1992,98(1):83-95
| (1) | The influence of sheep grazing of moderate grazing (MG), heavy grazing (HG), inordinate grazing (IG), over grazing (OG), and extinct grazing (EG) on vegetation succession was studied in the Stipa baicalensis steppe during 1984–1986. |
| (2) | The relationships between the relative sum of dominance ratio (RSDR) and the degree of succession (DS) at all stages of grazing succession in the Stipa baicalensis steppe were revealed in terms of the method of mathematical analysis under five grazing intensities mentioned above. |
| (3) | The dynamic models of grazing succession that are based on accurate grazing intensities in relation to succession courses were constructed using RSDR5, and DS. The models may explain the rules of grazing succession in the Stipa baicalensis steppe. |
9.
S. Chu J. R. Kennedy 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1994,175(4):505-518
| 1. | Direct contact between intra-epithelial nerve endings and ciliated cells was observed in frog (Rana pipiens) palate epithelium. |
| 2. | Electrical stimulation of the palatine nerve to the explant or the explant culture induced an increase in ciliary beat frequency in explant and outgrowth cells. |
| 3. | Atropine inhibited electrically stimulated ciliary beat frequency increase in the explant and outgrowth cells. |
| 4. | Gap junctional intercellular communication appears to be involved in the propagation of stimulated ciliary beat frequency increase from innervated to non-innervated ciliated cells. |
10.
J. Pernberg H. Machemer 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1989,164(4):551-562
| 1. | Properties of the membrane currents ofDidinium nasutum have been investigated under voltage clamp in different solutions and after deciliation. |
| 2. | Theearly transient Ca2+ inward current activates in a voltage-dependent manner. Inactivation is both Ca2+ -dependent and voltage-dependent. |
| 3. | Alate Ca2+ current rises with time to peak > 50 ms and decays in the order of seconds. |
| 4. | Activation and inactivation of the late Ca2+ current is voltage-dependent. |
| 5. | The delayed outward current is activated by voltage. The kinetics of this K+ current, but not its amplitude, are enhanced in the presence of intracellular EGTA. |
| 6. | The two voltage-dependent Ca2+ channels are located in the cilia, whereas all K+ channels are restricted to the somatic membrane. |
11.
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. |
12.
Structural aspects of the cytochromeb
6
f complex; structure of the lumen-side domain of cytochromef
W. A. Cramer S. E. Martinez D. Huang G. -S. Tae R. M. Everly J. B. Heymann R. H. Cheng T. S. Baker J. L. Smith 《Journal of bioenergetics and biomembranes》1994,26(1):31-47
The following findings concerning the structure of the cytochromeb
6
f complex and its component polypeptides, cytb
6, subunit IV and cytochromef subunit are discussed:
相似文献
| (1) | Comparison of the amino acid sequences of 13 and 16 cytochromeb 6 and subunit IV polypeptides, respectively, led to (a) reconsideration of the helix lengths and probable interface regions, (b) identification of two likely surface-seeking helices in cytb 6 and one in SU IV, and (c) documentation of a high degree of sequence invariance compared to the mitochondrial cytochrome. The extent of identity is particularly high (88% for conserved and pseudoconserved residues) in the segments of cytb 6 predicted to be extrinsic on then-side of the membrane. |
| (2) | The intramembrane attractive forces betweentrans-membrane helices that normally stabilize the packing of integral membrane proteins are relatively weak. |
| (3) | The complex isolated in dimeric form has been visualized, along with isolated monomer, by electron microscopy. The isolated dimer is much more active than the monomer, is the major form of the complex isolated and purified from chloroplasts, and is inferred to be a functional form in the membrane. |
| (4) | The isolated cytb 6 f complex contains one molecule of chlorophylla. |
| (5) | The structure of the 252 residue lumen-side domain of cytochromef isolated from turnip chloroplasts has been solved by X-ray diffraction analysis to a resolution of 2.3 Å. |
13.
The rich deciduous woodland at Loi, Luster, Inner Sogn, 61° 20 N., was traditionally used for fodder production from both tree and field layer. After more than nearly 40 years of disuse and secondary forest succession, experimental efforts were made to restore the traditional agricultural meadow woodland. Following a detailed preliminary registration of the vegetation the following measures were taken:
The main results are:
相似文献
| 1. | The understory tree layer, mainly Alnus incana was removed. |
| 2. | The old Ulmus glabra pollards were pruned back to traditional shape, as were some tall shurbs of Corylus avellana. |
| 3. | The field layer was mown once or twice yearly. |
| 1. | The pollarded elms have developed bundles of new twigs at the pruning points and are in good condition. |
| 2. | After an expansion of tall, nitrophilic herbs, e.g. Urtica dioica, Impatiens noli-tangere and Rubus idaeus, low and medium sized herbs and grasses have increased both in numbers, frequency and abundance. Helio- and thermophilic forest margin species are also more prominent. The moss layer has also become more dense and varied. |
| 3. | The average number of species in permanent plots has nearly doubled. |
14.
R. P. Smits N. M. Jansonius D. G. Stavenga 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1995,177(1):105-110
| 1. | The dependence of dark-adapted fly (Calliphora vicina) photoreceptors on oxygen was investigated by measuring the electroretinogram (ERG), the receptor potential, and the redox states of the mitochondrial cytochromes. The redox states were determined via reflection microspectrophotometry on white-eyed fly mutants. |
| 2. | The light sensitivity of the photoreceptors at oxygen fractions above 2% is identical to that in the normal (air) environment, as judged from both ERG and receptor potential. Light sensitivity is rather abruptly and strongly reduced at oxygen fractions lower than 1% and vanishes at anoxia (0%). |
| 3. | The redox state of the mitochondrial cytochromes also changes around oxygen fractions of 1–2%, but the dependence on oxygen fraction is less abrupt than that of ERG and receptor potential. |
| 4. | The mitochondrial activity of dark-adapted fly photoreceptors appears to be well-buffered, to warrant ample supply of metabolic energy for unimpaired photoreceptor function down to extremely low oxygen levels. |
15.
16.
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. |
17.
J. E. Brehe W. R. Fleming 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1976,110(2):159-169
| 1. | Seasonal changes in the half-times (0.5) for calcium influx and outflux in bone, skin and scales, and soft-tissue compartments ofF. kansae were measured. |
| 2. | The size of diffusible calcium pools in the three compartments was estimated from the ratio of the loading and unloading half-times. Both the bone and skin and scales compartments contain diffusible calcium pools which increase in size during the summer months. |
| 3. | The calcium in the soft-tissue compartment is all diffusible, and the kinetics indicate that this compartment receives calcium from the other two compartments. |
| 4. | Hypophysectomy reduced the rate of calcium turnover in summer animals to the levels measured in intact winter animals. Such treatment also affected the distribution of radiocalcium within the animal. |
| 5. | It is concluded that acellular bone is a metabolically active tissue. |
18.
Harvey J. Whitfield Jr. Linda S. Brady Mark A. Smith Evagelia Mamalaki Robert J. Fox Miles Herkenham 《Cellular and molecular neurobiology》1990,10(1):145-157
| 1. | We have described a general ribonucleotide probein situ hybridization methodology for localization of mRNA in frozen, unfixed tissue sections of brain. |
| 2. | The most important steps in obtaining consistent and reproducible autoradiographs with ribonucleotide probes were tissue acetylation and application of the radiolabeled probe to tissue sections under unsealed, glass coverslips. |
| 3. | Variability of the hybridization signal in tissue sections has been minimized to achieve a high degree of reproducibility within a given experiment as determined by densitometric analysis of rat glucocorticoid and mineralocorticoid receptor mRNA hybridization autoradiographs. |
| 4. | Tissue quality has been optimized for high-resolution anatomical localization of mRNA species by nuclear track emulsion. |
| 5. | The protocol is amenable to rapid, batchwise processing of tissue samples. |
19.
R. Garcia F. Gaillard J. -C. Jacquenod 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1988,162(4):443-451
Ipsilateral retino-tecto-tectal (IRTT) units were recorded extracellularly in the rostral optic tectum of the frog (Rana esculenta). The activity of 79 superficial units (II type) was quantified in response to black disks of various sizes, moved vertically at various angular velocities and against a white background. The contrast ¦C¦ was constant during the experiments. Neuronal activity was analysed by two methods, yielding identical results:
The results show that qualitatively and quantitatively, the properties of I1 units are very similar to R1–R2 (sustained) ganglion cells. 相似文献
| (1) | I1 units responded transiently to moving and movement gated stationary stimuli; these units did not seem to be directionally sensitive nor responsive to changes in background illumination. Fifty-three % of units had a low spontaneous activity. |
| (2) | A power function relating mean firing frequency (¯R) and angular velocity (v) was established in the majority (78%) of units. The exponent and the constantk were 0.44–0.8 and 8.9–20, respectively. |
| (3) | The relationship between¯R and stimulus diameter (D) was best expressed by a logarithmic function. The maximum response occurred forD= 2–4. The optimal stimulus diameter was found to be independent of stimulus velocity. |
| (4) | When stimulated repetitively under steady conditions, I1 units showed about 10% fluctuations in mean response, which seemed to increase with stimulus diameter. |
20.
Rolf Bergmann 《Antonie van Leeuwenhoek》1989,55(2):143-152
Thiolutin was found to inhibit the utilization of glucose and other growth substrates in Escherichia coli. The inhibition was detected by a sharp drop of the respiration rate after addition of the antibiotic. The actual function affected was allocated to the cytoplasmic membrane of the bacterial cells by the following evidence:
It was concluded that the transport of certain substrates across the membrane was inhibited. 相似文献
| – | - spheroplasts were affected like intact cells, |
| – | - individual reactions of either the electron transport chain or the glycolytic pathway were not inhibited, |
| – | - glucose consumption in the culture stopped and the cells accumulated guanosine tetraphosphate as under starvation conditions, |
| – | - activation of the cell's apo-glucose dehydrogenase restored respiration via bypassing the glucose phosphotransferase system. |