Arginine activity in the proton-motive photocycle of bacteriorhodopsin: solid-state NMR studies of the wild-type and D85N proteins

15N solid-state NMR (SSNMR) spectra of guanidyl-15N-labeled bacteriorhodopsin (bR) show perturbation of an arginine residue upon deprotonation of the retinal Schiff base during the photocycle. At the epsilon position, an upfield shift of 4 ppm is observed while the eta nitrogens develop a pair of 'wing' peaks separated by 24 ppm. Proton-driven spin diffusion between the two 'wing' peaks indicates that they arise from a single Arg residue. An unusually asymmetric environment for this residue is indicated by comparison with guanidyl-15N chemical shifts in a series of arginine model compounds. The 'wing' peaks are tentatively assigned to Arg-82 on the basis of the SSNMR investigations of the alkaline and neutral dark-adapted forms of the D85N bacteriorhodopsin mutant. Another, less asymmetric pair of eta signals, that is not affected by Schiff base deprotonation or D85 mutation, is tentatively assigned to Arg-134. The results are discussed in relation to existing models of bR structure and function.     

LIPOXYGENASE ACTIVITIES IN RIPENING OLIVE FRUIT TISSUE

Extracts of ripening olive fruits (Olea europaea L. cv. Kalamata) ‐were analyzed for the presence of lipoxygenase activity and for the content of phenolic compounds, which are lipoxygenase inhibitors. Two distinct lipoxygenase activities were identified by their pH optima and sensitivity to the inhibitor nordihydroguaiaretic acid (NDGA). Both activities were low during early ripening stages, and increased sharply between 57 and 94 days postanthesis, reaching a plateau at about 120 days. The content of phenolic compounds, mainly oleuropein, changed in the opposite way, suggesting their involvement in the regulation of the two lipoxygenase activities during the olive fruit development. The two lipoxygenase activities could have a role in fruit maturation and senescence.     

Forgiveness as an intrapsychic process.

Reviews the literature on forgiveness, considers it as a health-inducing process, and offers an intrapsychic conceptualization of forgiveness. An object relations model based on the schema proposed by J. Gartner (1988) explains forgiveness as a lengthy process of self and object representations and complementary defenses undergoing a series of remodifications to develop optimal resolution. Simultaneously, other psychic agencies are disrupted by altering internal images and defenses, broadening the scope of resulting disequilibrium. Gradual, congruent, parallel revision of major psychic systems is necessary for real absolution and exoneration. An illustrative case example of a 36-yr-old married female with depression is provided. The application of this object relations model of forgiveness in psychotherapy and psychoanalysis is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

正交检测方法在钢铁铸造中的应用

在设计一种基于预测控制器模型时，最关键的工作是识别一个合理可靠的过程模型。在钢铁厂的连续铸造线上识别铸模液位模型是很困难的，由于极高的随机干扰水平，使得众所周知的随机阶跃函数，ＰＲＢＳ或随机试验输入等参数识别方法都以失败告终。而本文介绍的基于正交检测的方法给出了令人满意的结果。     

Collaborative Network Topologies in Spatial Economies

Networks and Spatial Economics - Recently, it has been shown that networks with an arbitrary degree sequence may be a stable solution to a network formation game. Further, in recent years there has...     

18F]fluoroethoxy-benzovesamicol, a PET radiotracer for the vesicular acetylcholine transporter and cholinergic synapses

CACO-2 BBE was used to determine the response of a gastrointestinal epithelium to tumor necrosis factor-alpha (TNF). Incubation of CACO-2 BBE with TNF did not produce any effect on transepithelial resistance (TER) within the first 6 hr but resulted in a 40-50% reduction in TER and a 30% decrease in 1SC (short circuit current) relative to time-matched control at 24 hr. The decrease in TER was sustained up to 1 week following treatment with TNF and was not associated with a significant increase in the transepithelial flux of [14C]-D-mannitol or the penetration of ruthenium red into the lateral intercellular space. Dilution potential and transepithelial 22Na+ flux studies demonstrated that TNF-treatment of CACO-2 BBE cell sheets increased the paracellular permeability of the epithelium to Na+ and Cl-. The increased transepithelial permeability did not associate with an increase in the incidence of apoptosis. However, there was a TNF-dependent increase in [3H]-thymidine labeling that was not accompanied by a change in DNA content of the cell sheet. The increase in transepithelial permeability was concluded to be across the tight junction because: (i) 1 mM apical amiloride reduced the basolateral to apical flux of 22Na+, and (ii) dilution potential studies revealed a bidirectionally increased permeability to both Na+ and Cl-. These data suggest that the increase in transepithelial permeability across TNF-treated CACO-2 BBE cell sheets arises from an alteration in the charge selectivity of the paracellular conductive pathway that is not accompanied by a change in its size selectivity.     

Relationship between the anisotropy tensor calculated through global and object measurements in high-resolution X-ray tomography on cellular and composite materials

Structural anisotropy of two-phase materials can be evaluated through global measurements, as volume orientation or mean-intercept length methods do, or through statistics performed on a set of individual measurements. This last procedure is encouraged by recent improvements in the spatial resolution of conventional X-ray tomography. In this paper, the above-described approaches were compared in three case studies: a foam subjected to an in situ compression test, a second foam with a completely different cell morphology and a plastic material reinforced with short fibres. The approach based on the subdivision into distinguishable objects of the considered material phase has proved to be more sensitive in highlighting small deformations in the structure or small irregularities in an otherwise isotropic structure. On the other hand, the other approach is more general and is always usable. The two methods for calculating the fabric tensor tend to converge as the average anisotropy of individual objects in the statistical population increases. The use of Lambert's cylindrical equal-area projection of cell/fibre directions or local volume orientations is suggested, because the density of points is preserved from the sphere to the plane surface. Finally, a quick vector method to evaluate the anisotropy of the directions distribution has been presented, by defining a coherence index of the average direction.     

纤维的结构和性能（Ⅷ）

继续前报内容介绍高速纺丝Ｎｙｌｏｎ６纤维的结构和性能：密度随纺丝速度而变化，以有纤维的Ｘ射线衍射图像，晶型和力学性质。     

VOLTAGE COLLAPSE AND CONTROL ACTIONS: EFFECTS AND LIMITATIONS

ABSTRACT

This paper focuses on control actions determination for voltage collapse prevention. Sensitivity matrices are proposed based on the knowledge of the critical bus. By critical bus one means that bus whose state variables vary at most at the voltage collapse point. A tangent vector is used to identify the critical bus, and its behavior as a function of load increase is also investigated and compared with other indices previously proposed. It is shown that generator control actions may not work to increase voltage collapse margin, whereas local control actions may produce better results. The tests are carried out in the IEEE-300 bus test system, with and without reactive power limits consideration.