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81.
Kati Lindström 《Biosemiotics》2010,3(3):359-373
Juri Lotman distinguishes between two main types of communication. In addition to the classical I-YOU communication, he speaks
about I-I communication, where both the addresser and the addressee are one and the same person. Contrary to how it sounds,
autocommunication is not self-sufficient musing inside one’s self, it is remodelling oneself through a code from an entity
outside oneself, be it animate or inanimate. According to Lotman, it is often the rhythmical phenomena like poetry, the rhythm
of waves, etc. that lend themselves for the act of autocommunication as external codes. After having received the message
one is not identical to the original oneself anymore. Perceptual markers of landscape—specific rhythms, ephemera, the rhythm
of human everyday activities, bodily movement—can be considered as a secondary code leading to autocommunication in the person
who contemplates the landscape. Looking at the landscape—which also implies the rhythmical movement of the eyes—one uses it
as a code to reconstitute oneself. A person who has confronted a landscape does not leave it as the same person. The present
article poses a definition of autocommunication in landscapes and discusses the way in which other sensorial information apart
from the visual—smell, movement, rhythms etc—are used culturally to reinforce autocommunication with oneself. It can be said
that several institutionalised religious and cultural practices expect the subject to reconstitute him- or herself mainly
through the bodily landscape experience. 相似文献
82.
V E Koteliansky A M Belkin M G Frid M A Glukhova 《Biochemical Society transactions》1991,19(4):1072-1076
Phenotypic variability of vascular smooth muscle cells (SMCs) can serve as a good model for studying the mechanisms regulating the expression of adhesion-mediating proteins. To describe phenotypic changes of human aortic SMCs, we have studied the expression of cytodifferentiation-related adhesion-mediating proteins in samples of media from fetal, child and adult human aorta, and in subendothelial intima of normal and atherosclerotic aorta. We have shown that during prenatal and post-natal development vascular SMCs co-ordinately change several times the expression of certain differentiation-related proteins. Our data show the existence of certain groups of proteins whose expression during smooth muscle development might be controlled by two basic mechanisms: selection of genes to be expressed at particular developmental stages and generation of several different protein variants from a single gene via alternative RNA splicing. 相似文献
83.
We have reported [(1984) Cancer Res., in press] that estramustine phosphate inhibits microtubule assembly and disassembled preformed microtubules. We now present evidence that estramustine phosphate inhibits microtubule assembly by binding to the microtubule-associated proteins. We have found that: additional microtubule-associated proteins relieved the inhibition of assembly by estramustine phosphate; 3H-labelled estramustine phosphate bound predominantly to the microtubule-associated proteins; and the content of the microtubule-associated proteins was reduced in taxol reversed estramustine phosphate-inhibited microtubules. 相似文献
84.
Kati Karhula Tarja Hakola Aki Koskinen Anneli Ojajärvi Mika Kivimäki Mikko Härmä 《Chronobiology international》2018,35(6):785-794
ABSTRACTWe aimed to study whether permanent night workers sleep and psychosocial factors differ from day workers and shift workers. The participants (n = 9 312, 92% females, average age 45 years, most commonly nurses and departmental secretaries) were day workers (DW, n = 2 672), shift workers (SW, n = 6 486) and permanent night workers (PNW, n = 154). The Finnish Public Sector survey responses from six hospital districts from 2012 were combined to payroll data from 91 days preceding the survey. The data were analyzed using Pearson χ2-test, one-way ANOVA and multinomial logistic regression analysis. The PNWs reported slightly longer average sleep length than the SWs or the DWs (7:27 vs. 7:13 and 7:10 h, p < 0.001). The PNWs reported least often difficulties in maintaining sleep (p < 0.001) compared to the SWs and the DWs. The PNWs reported most often difficulties to fall asleep and fatigue during free-time (p-values <0.001). The DWs and PNWs experienced less often work-life conflict than the SWs (25 and 26 vs. 38%, p < 0.001). The PNWs were more often satisfied with autonomy at work and appreciation and fair treatment by colleagues than the DWs or the SWs (p < 0.001). The SWs and PNWs reported remarkably higher occurrence of verbal (p < 0.001, OR 3.71, 95% CI 3.23–4.27 and OR 7.67, 95% CI 5.35–10.99, respectively) and physical workplace violence (p < 0.001, OR 9.24, 95% CI 7.17–11.90 and OR 28.34, 95% CI 16.64–43.06, respectively) compared to DWs. Conclusively, PNWs reported contradictory differences in sleep quality compared to DWs and SWs. PNWs are more often satisfied with their colleagues and autonomy at work than DWs or SWs but face workplace violence remarkably more often. 相似文献
85.
Shraddha Shukla Anil Kumar Verma Ilkka Kajala Antti Nyyssolä Rwivoo Baruah Kati Katina 《Preparative biochemistry & biotechnology》2016,46(8):822-832
The dextransucrase gene from Weissella confusa Cab3, having an open reading frame of 4.2?kb coding for 1,402?amino acids, was amplified, cloned, and expressed in Lactococcus lactis. The recombinant dextransucrase, WcCab3-rDSR was expressed as extracellular enzyme in M17 medium with a specific activity of 1.5?U/mg which after purification by PEG-400 fractionation gave 6.1?U/mg resulting in 4-fold purification. WcCab3-rDSR was expressed as soluble and homogeneous protein of molecular mass, approximately, 180?kDa as analyzed by SDS-PAGE. It displayed maximum enzyme activity at 35°C at pH 5.0 in 50?mM sodium acetate buffer. WcCab3-rDSR gave Km of 6.2?mM and Vm of 6.3?µmol/min/mg. The characterization of dextran synthesized by WcCab3-rDSR by Fourier transform infrared and nuclear magnetic resonance spectroscopic analyses revealed the structural similarities with the dextran produced by the native dextransucrase. The modeled structure of WcCab3-rDSR using the crystal structures of dextransucrase from Lactobacillus reuteri (protein data bank, PDB id: 3HZ3) and Streptococcus mutans (PDB id: 3AIB) as templates depicted the presence of different domains such as A, B, C, IV, and V. The domains A and B are circularly permuted in nature having (β/α)8 triose phosphate isomerase-barrel fold making the catalytic core of WcCab3-rDSR. The structure superposition and multiple sequence alignment analyses of WcCab3-rDSR with available structures of enzymes from family 70 GH suggested that the amino acid residue Asp510 acts as a nucleophile, Glu548 acts as a catalytic acid/base, whereas Asp621 acts as a transition-state stabilizer and these residues are found to be conserved within the family. 相似文献
86.
Effects of proteolysis of the extending parts of the high-molecular-weight microtubule-associated proteins on interactions between microtubules 总被引:1,自引:0,他引:1
Digestion of assembled microtubules with agarose-bound trypsin was performed to obtain microtubules which lack the extending projections, the non-tubulin-binding part of the high-molecular-weight microtubule-associated proteins. The assembly kinetics and the minimum protein concentration for assembly were the same for these trypsinated microtubules as for normal, untreated microtubules. Furthermore, the digested microtubules gave rise to the same change in turbidity per polymer mass as that found for normal microtubules. However, electron microscopy of pelleted microtubules revealed a closer packing after trypsin treatment. A substantially lower increase in specific viscosity was found upon assembly. At concentrations of above approx. 1.5 mg/ml, the viscosity of trypsin-treated microtubules was almost independent of the protein concentration, in contrast to the turbidity, which still increased. Both microtubules and the trypsin-digested microtubules were easily oriented by shear, although the flow linear dichroism signal for the microtubules after trypsin treatment was only half of that found for perfectly oriented normal microtubules. At higher shear force gradients, digested microtubules aggregated side by side as shown by electron microscopy. This was not found for normal microtubules. Even although the extending parts of the high-molecular-weight proteins are not needed for assembly, they were found to play an important role in microtubule orientation and interactions between microtubules, probably by acting as spacers between microtubules. 相似文献
87.
Contribution of a single hydroxyl group to transition-state discrimination by adenosine deaminase: evidence for an "entropy trap" mechanism 总被引:2,自引:0,他引:2
Adenosine deaminase was found to bind 6-hydroxy-1,6-dihydropurine ribonucleoside (II), formed by reversible addition of water to purine ribonucleoside (I) in a reaction analogous to formation of a tetrahedral intermediate in substrate deamination, with an apparent Ki value of 3 x 10(-13) M at 20 degrees C. 1,6-Dihydropurine ribonucleoside (IV), synthesized by photolysis of purine ribonucleoside in the presence of NaBH4, exhibited a Ki value of 5.4 x 10-6 M. After correction for differences between the relative free energies of solvation of II and IV, the 6-hydroxyl group of II was estimated to contribute more than 16 kcal to the free energy of binding, approaching the enthalapy of formation of a single hydrogen bond to charged group in the vapor phase. The relatively weak binding of IV and of substrate water suggests that entropic effects, arising from the cooperative action of binding determinants contained within these separate molecules, contribute more than 10 kcal/mol to the free energy of binding of II in which these binding determinants are contained within a single molecule. In free solution, the entropy of reversible hydration of I was evaluated by measuring the temperature dependence of equilibria of protonation of I and of pseudobase formation from I-methylpurinium ribonucleoside as -35 eu, comparable with the entropy of activation for the uncatalyzed hydrolysis of adenosine. In the active site of adenosine deaminase, this thermodynamic obstacle is evidently climbed spontaneously as a result of attractive interactions between the active site and the critical hydroxyl group at the 6-position.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
88.
89.
Patrick Constantinescu Kati Kovacevic Giel J.C.G.M. Bosman Ronald Sluyter 《生物化学与生物物理学报:生物膜》2010,1798(9):1797-1804
Extracellular ATP induces cation fluxes in and impairs the growth of murine erythroleukemia (MEL) cells in a manner characteristic of the purinergic P2X7 receptor, however the presence of P2X7 in these cells is unknown. This study investigated whether MEL cells express functional P2X7. RT-PCR, immunoblotting and immunofluorescence staining demonstrated the presence of P2X7 in MEL cells. Cytofluorometric measurements demonstrated that ATP induced ethidium+ uptake into MEL cells in a concentration-dependent fashion and with an EC50 of ∼ 154 μM. The most potent P2X7 agonist 2′- and 3′-0(4-benzoylbenzoyl) ATP, but not ADP or UTP, induced ethidium+ uptake. ATP-induced ethidium+ and YO-PRO-12+ uptake were impaired by the P2X7 antagonist, A-438079. A colourmetric assay demonstrated that ATP impaired MEL cell growth. A cytofluorometric assay showed that ATP induced MEL cell death and that this process was impaired by A-438079. Finally, cytofluorometric measurements of Annexin-V binding and bio-maleimide staining demonstrated that ATP could induce rapid phosphatidylserine exposure and microparticle release in MEL cells respectively, both of which were impaired by A-438079. These results demonstrate that MEL cells express functional P2X7, and indicate that activation of this receptor may be important in the death and release of microparticles from red blood cells in vivo. 相似文献
90.