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91.
Nicholas?H?CarbonettiEmail author R?Michael?Mays Galina?V?Artamonova Roger?D?Plaut Zo??EV?Worthington 《BMC microbiology》2005,5(1):7
Background
Pertussis toxin (PT) is an exotoxin virulence factor produced by Bordetella pertussis, the causative agent of whooping cough. PT consists of an active subunit (S1) that ADP-ribosylates the alpha subunit of several mammalian G proteins, and a B oligomer (S2–S5) that binds glycoconjugate receptors on cells. PT appears to enter cells by endocytosis, and retrograde transport through the Golgi apparatus may be important for its cytotoxicity. A previous study demonstrated that proteolytic processing of S1 occurs after PT enters mammalian cells. We sought to determine whether this proteolytic processing of S1 is necessary for PT cytotoxicity. 相似文献92.
Effects of neonatal fluvoxamine administration to white rats and their correction by semax treatment
M. A. Volodina S. A. Merchieva E. A. Sebentsova N. Yu. Glazova D. M. Manchenko L. A. Andreeva N. G. Levitskaya A. A. Kamensky N. F. Myasoedov 《Biology Bulletin》2014,41(4):372-377
The aim of this work was to study the delayed effects of chronic neonatal administration of the selective serotonin reuptake inhibitor fluvoxamine (FA) to white rat pups and to estimate the possibility to correct these effects by treatment with semax. Fluvoxamine was injected intraperitoneally at a dose of 10 mg/kg from postnatal days 1 to 14, and semax was injected intranasally at a dose of 0.05 mg/kg from postnatal days 15 to 28. It was shown that neonatal FA administration produced a significant delay in animal somatic growth. A loss in body weight was detected both during FA administration and 4–6 weeks after the last injection. Furthermore, FA administration increased the anxiety level and disturbed the learning ability of animals. The negative consequences of neonatal FA administration were largely compensated by Semax. 相似文献
93.
Almir S Zanca Renato Vicentini Fausto A Ortiz-Morea Luiz EV Del Bem Marcio J da Silva Michel Vincentz Fabio TS Nogueira 《BMC plant biology》2010,10(1):260
Background
MicroRNAs (miRNAs) are small regulatory RNAs, some of which are conserved in diverse plant genomes. Therefore, computational identification and further experimental validation of miRNAs from non-model organisms is both feasible and instrumental for addressing miRNA-based gene regulation and evolution. Sugarcane (Saccharum spp.) is an important biofuel crop with publicly available expressed sequence tag and genomic survey sequence databases, but little is known about miRNAs and their targets in this highly polyploid species. 相似文献94.
The genetic basis of the effects of domestication has previously been examined in relation to morphological, physiological and behavioural traits, but not for vocalizations. According to Belyaev [Belyaev, D.K., 1979. Destabilizing selection as a factor in domestication. J. Hered. 70, 301-308], directional selection for tame behaviour toward humans resulted in domestication. This hypothesis has been confirmed experimentally on the farm-bred silver fox Vulpes vulpes population that has undergone 45 years of artificial selection for tameness and 35 years of selection for aggressiveness. These foxes, with their precisely known attitudes toward people, provide a means of examining vocal indicators of tameness and aggressiveness to establish the genetic basis for vocal production in canids. We examined vocalizations toward people in foxes selected for tameness and aggressiveness compared to those of three kinds of crosses: Hybrids (Tame × Aggressive), A-Backcrosses (Aggressive × Hybrid) and T-Backcrosses (Tame × Hybrid). We report the effects of selection for tameness on usage and structure of different vocalizations and suggest that vocal indicators for tameness and aggressiveness toward people are discrete phenotypic traits in silver foxes. 相似文献
95.
Distinctiveness of chicks’ calls may arise in ontogenesis when parents can confuse their own and alien chicks, leaving their
nests and forming crèches or flocks. It is unknown, however, whether the individual vocal signature retains further in ontogenesis
or relaxes when the necessity in the parental care disappears. In this paper, we study the inter- and intra-individual variations
of the acoustic parameters in chicks’ calls in the red-crowned crane Grus japonensis, the species with prolonged development enveloping three stages: territorial under parental care, in flocks under parental
care and in flocks self-independently. We found, that discriminability of chicks’ calls increased significantly to the second
stage, characterized by the maximum risk for parents to confuse the own and alien chicks, and significantly decreased to the
third stage, when the needs in the parent–chick vocal recognition disappeared. Our data agree with a hypothesis that the individual
distinctiveness decreases in the absence of necessity in accuracy of parent–chick recognition. 相似文献
96.
Vocal indicators of welfare have proven their use for many farmed and zoo animals and may be applied to farmed silver foxes
as these animals display high vocal activity toward humans. Farmed silver foxes were selected mainly for fur, size, and litter
sizes, but not for attitudes to people, so they are fearful of humans and have short-term welfare problems in their proximity.
With a human approach test, we designed here the steady increase and decrease of fox–human distance and registered vocal responses
of 25 farmed silver foxes. We analyzed the features of vocalizations produced by the foxes at different fox–human distances,
assuming that changes in vocal responses reflect the degrees of human-related discomfort. For revealing the discomfort-related
vocal traits in farmed silver foxes, we proposed and tested the algorithm of “joint calls,” equally applicable for analysis
of all calls independently on their structure, either tonal or noisy. We discuss that the increase in proportion of time spent
vocalizing and the shift of call energy toward higher frequencies may be integral vocal characteristics of short-term welfare
problems in farmed silver foxes and probably in other captive mammals. 相似文献
97.
We examined the production of different vocalizations in three strains of silver fox (unselected, aggressive, and tame) attending three kinds of behavior (aggressive, affiliative, and neutral) in response to their same-strain conspecifics. This is a follow-up to previous experiments which demonstrated that in the presence of humans, tame foxes produced cackles and pants but never coughed or snorted, whilst aggressive foxes produced coughs and snorts but never cackled or panted. Thus, cackle/pant and cough/snort were indicative of the tame and aggressive fox strains respectively toward humans. Wild-type unselected foxes produced cough and snort toward humans similarly to aggressive foxes. Here, we found that vocal responses to conspecifics were similar in tame, aggressive and unselected fox strains. Both cackle/pant and cough/snort occurred in foxes of all strains. The difference in the use of cackle/pant and cough/snort among these strains toward humans and toward conspecifics suggest that silver foxes do not perceive humans as their conspecifics. We speculate that these vocalizations are produced in response to a triggering internal state, affiliative or aggressive, that is suppressed by default in these fox strains toward humans as a result of their strict selection for tame or aggressive behavior, whilst still remaining flexible toward conspecifics. 相似文献
98.
99.
Characteristics of copper binding sites in the bacteria E. coli were studied using ESR spectroscopy. It was found that these cations had high local density on the strong binding range represented by the two type sites. The former include nitrogen and oxygen ligands and the second ones--sulfur of the thiol biomolecules. The weak coupling Cu(II) sites of E. coli represent more polar nitrogen-oxygen environment. Blocking SH-groups by N-ethylmaleimide makes them inaccessible for copper ligation, sharply increases the percentage of ESR-detectable copper of the strong-binding sites and prevents the membrane breakdown by these cations. The results suggest that the Cu(2+)-induced membrane damage is the effect of Cu2+ binding with the SH-containing sites of the bacterial membrane. 相似文献
100.
T T Volodina T N Pechenova V V Pliatsko Iu A Stavinski? A K Shimanovskaia N A Nosal' E V Solodova 《Ukrainski? biokhimicheski? zhurnal》1991,63(4):47-51
Type II collagen of human cartilage has been comparatively studied in norm and at deforming arthrosis. Collagen preparations are characterized by aminoacid composition and electrophoretic mobility in polyacrylamide gel. It is supposed that at deforming arthrosis the degenerative-dystrophic processes in the articular cartilage of man are caused by appearance of procollagen. 相似文献