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21.
George A. Gescheider Burak GüÇlü Jessica L. Sexton Sarah Karalunas Anne Fontana 《Somatosensory & motor research》2013,30(4):255-268
Psychophysical thresholds for the detection of a 300-Hz burst of vibration applied to the thenar eminence were measured for stimuli applied to the skin through 1.5?cm2 and through 0.05?cm2 contactors. Thresholds were approximately 13?dB lower when the area of the contactor was 1.5?cm2 than when it was 0.05?cm2. The difference between the thresholds measured with the large and small contactors was significantly reduced when only the lowest thresholds obtained in the testing sessions were considered. This result supports the hypothesis that one component of spatial summation in the P channel is probability summation. In addition, threshold measurements within a session were less variable when measured with the 1.5?cm2 contactor. We conclude that spatial summation in the P channel is a joint function of two processes that occur as the areal extent of the stimulus increases: probability summation in which the probability of exceeding the psychophysical detection threshold increases as the number of receptors of varying sensitivities increases, and neural integration in which neural activity originating from separate receptors is combined within the central nervous system rendering the channel more sensitive to the stimulus. 相似文献
22.
The question of Kurdish language rights has been a central issue in the Turkish–Kurdish conflict. The current study examined endorsement of Kurdish language rights in relation to intergroup factors (i.e. group identifications, cross-group friendships, perceived discrimination, and perceived out-group beliefs about state unity) among self-identified Turkish and Kurdish participants. The results indicate that Turks were much less in favour of these rights than the Kurds. In addition, for the Turks, higher national and ethnic identification were associated with lower support for Kurdish language rights, while cross-group friendship, perceived discrimination of Kurds and the belief that Kurds endorse national unity were associated with more support for rights. For the Kurdish participants, stronger national identification seems to undermine the mobilizing meaning that Kurdish group identification has for language rights support. Furthermore, friendship with Turks can undermine the support for rights because it strengthens national identification and reduces ethnic identification. 相似文献
23.
Mona Gazel Kadriye Çağlayan Hüseyin Başpınar Juan F. Mejia Samanta Paltrinieri Assunta Bertaccini Nicoletta Contaldo 《Journal of Phytopathology》2016,164(2):136-140
Symptoms resembling those associated with phytoplasma presence were observed in pomegranate (Punica granatum L.) trees in June 2012 in the Aegean Region of Turkey (Ayd?n province). The trees exhibiting yellowing, reduced vigour, deformations and reddening of the leaves and die‐back symptoms were analysed to verify phytoplasma presence. Total nucleic acids were extracted from fresh leaf midribs and phloem tissue from young branches of ten symptomatic and five asymptomatic plants. Nested polymerase chain reaction assays using universal phytoplasma‐specific 16S rRNA and tuf gene primers were performed. Amplicons were digested with Tru1I, Tsp509I and HhaI restriction enzymes, according to the primer pair employed. The phytoplasma profiles were identical to each other and to aster yellows (16SrI‐B) strain when digestion was carried out on 16Sr(I)F1/R1 amplicons. However, one of the samples showed mixed profiles indicating that 16SrI‐B and 16SrXII‐A phytoplasmas were present when M1/M2 amplicons were digested, the reamplification of this sample with tuf cocktail primers allowed to verify the presence of a 16SrXII‐A profile. One pomegranate aster yellows strain AY‐PG from 16S rRNA gene and the 16SrXII‐A amplicon from tuf gene designed strain STOL‐PG were directly sequenced and deposited in GenBank under the Accession Numbers KJ818293 and KP161063, respectively. To our knowledge, this is the first report of 16SrI‐B and 16SrXII‐A phytoplasmas in pomegranate trees. 相似文献
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S. Ayla M. E. Okur M. Y. Günal E. M. Özdemir D. Çiçek Polat A. Yoltaş 《Biotechnic & histochemistry》2019,94(3):180-188
Laurocerasus officinalis Roem. (syn: Prunus laurocerasus L.) is a member of Rosaceae family. We investigated the antimicrobial and antioxidant activity of L. officinalis Roem in wound healing both in vivo and in vitro using an excisional wound model model in mice. We used four groups of eight mice as follows: untreated (control), empty gel, extract + gel (L. officinalis + gel), and Madecassol® groups. All treatments were applied topically once daily. The scar area, percentage wound closure and epithelization time were measured. L. officinalis promoted wound healing and increased granulation tissue, epidermal regeneration and angiogenesis. L. officinalis extract, which is known for its antioxidant and antimicrobial activities, may be useful for promoting wound healing. 相似文献
25.
Hacer Esen Saadet Alpdağtaş Mehmet Mervan Çakar 《Preparative biochemistry & biotechnology》2019,49(5):529-534
AbstractSeveral protein expression systems can be used to get enzymes in required quantities and study their functions. Incorporating a polyhistidine tag is a beneficial way of getting various enzymes such as FDHs for industrial applications. The NAD+ dependent formate dehydrogenase from Chaetomium thermophilum (CtFDH) can be utilized for interconversion of formate to carbon dioxide coupled with the conversion of NAD+ to NADH. In this study, N-terminal His tagged CtFDH (N-CtFDH) and C-terminal His tagged CtFDH (C-CtFDH) was constructed to learn the effect of His tag location on the activity and kinetic parameters of the enzyme. The solubility of proteins was not affected by tag position, however, an interference on the N-terminal region caused a deterioration in specific activity and the kinetic ability of enzyme. The obtained results indicated that the C-terminus of the enzyme is an appropriate region for tag engineering. The C-CtFDH has an approximately three-fold larger specific activity and two-fold higher catalytic efficiency than N-CtFDH. The results suggest that insertion of a His-tag at the N-terminal or C-terminal end of CtFDH has different effects on the protein and the N-terminal fragment of the protein is crucial for the function of CtFDH. 相似文献
26.
Biology Bulletin - In the trout production establishments all over the world, the most common pathogenic bacterial factors are increasing. Therefore, in this study, rainbow trout (Oncorhynchus... 相似文献
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A set of PCR primers based on the genome sequence were used to clone a gene encoding a hypothetical nitroreductases (named as Ssap-NtrB) from uropathogenic staphylococcus, Staphylococcus saprophyticus strain ATCC 15305, an oxygen insensitive flavoenzyme. Activity studies of the translation product revealed that the nitroreductase catalyses two electron reduction of a nitroaromatic drug of nitrofurazone (NFZ), cancer prodrugs of CB1954 and SN23862 at optimum temperature of 20 °C together with retaining its maximum activity considerably at 3 °C. The required electrons for such reduction could be supplied by either NADH or NADPH with a small preference for the latter. The gene was engineered for heterologous expression in Escherichia coli, and conditions were found in which the enzyme was produced in a mostly soluble form. The recombinant enzyme was purified to homogeneity and physical, spectral and catalytical properties were determined. The findings lead us to propose that Ssap-NtrB represents a novel nitro reductase with an unusual cold active property, which has not been described previously for prodrug activating enzymes of nitroreductases. 相似文献
30.
JOSÉ F. GONÇALVES JR RENAN S. REZENDE NARLIANE M. MARTINS RENER S. GREGÓRIO 《Austral ecology》2012,37(7):807-815
The hypothesis of this study was that colonizers in decaying leaf litter prefer native species (Erythrina verna) to exotic ones (Eucalyptus camaldulensis and Protium heptaphyllum). Therefore, native species are expected to show higher breakdown rates, increased biomass, richness and density of invertebrate species, and increased biomass of decomposer fungi. Breakdown of leaf litter from these three species was assessed in an Atlantic Rain Forest stream. Four samples were collected during a period of 90 days and washed on a sieve to separate the invertebrates. Then, a series of leaf disks were cut to determine ash‐free dry mass and fungal biomass, and the remaining material was oven‐dried to determine the dry weight. Eucalyptus camaldulensis and E. verna showed higher breakdown rates than P. heptaphyllum, due to differences in leaf physical and chemical characteristics. The harder detritus (P. heptaphyllum) broke down more slowly than detritus with high concentrations of labile compounds (E. camaldulensis). The density of the invertebrates associated with detritus increased with time. There were no differences in density, taxonomic richness or biomass of invertebrates among the leaf types, which indicated that the invertebrates did not distinguish between exotic and native detritus. Fungal colonization varied among samples; E. camaldulensis showed the lowest ergosterol concentrations, mainly due to a high concentration of total phenolics. The detritus with the highest hardness value was colonized most slowly by fungi. These results showed that leaf breakdown in Atlantic Rain Forest streams could be affected either by changes in riparian vegetation, or by becoming more savanna‐like process due to climate change. 相似文献