1,590 research outputs found
The Critical Aggregation Concentration of ß-Lactoglobulin-Based Fibril Formation
The critical aggregation concentration (CAC) for fibril formation of ß-lactoglobulin (ß-lg) at pH 2 was determined at 343, 353, 358, 363, and 383 K using a Thioflavin T assay and was approximately 0.16 wt%. The accuracy of the CAC was increased by measuring the conversion into fibrils at different stirring speeds. The corresponding binding energy per mol, as determined from the CAC, was 13 RT (~40 kJ mol¿1) for the measured temperature range. The fact that the CAC was independent of temperature within the experimental error indicates that the fibril formation of ß-lg at pH 2 and the measured temperature range is an entropy-driven process
Аграрне перенаселення в українських губерніях Російської імперії початку ХХ ст.
Sustainable urban development is a critical issue in the Netherlands. The country is densely populated, which causes conflicts between environmental concerns and spatial development. Environmental policy integration is proposed as a way to improve the integration of environmental values into spatial planning with the help of learning processes. This chapter evaluates the extent to which the combination of a map-based touch table and an area-specific environmental profile are of added value to environmental policy integration. The case study is the application of the map-based touch table, called MapTable® for the development of a sustainable neighborhood in the region of Utrecht, the Netherlands. It was found that MapTable® facilitates learning processes by providing a platform for communication among stakeholders from different backgrounds. Nonetheless, it must be ensured that all stakeholders are equally included, and that the process suits the application of a map-based touch table in combination with an area-specific environmental profile
Sensitivity for reverse-phi motion
AbstractLow-level contrast information in the primary visual pathway is represented in two different channels. ON-center cells signal positive contrasts and OFF-center cells signal negative contrasts. In this study we address the question whether initial motion analysis is performed separately in these two channels, or also through combination of signals from ON and OFF cells. We quantitatively compared motion coherence detection for regular and for reverse-phi motion stimuli. In reverse-phi motion the contrast of a pattern flips during displacements. Sensitivity is therefore based on correlating positive and negative contrasts, whereas for regular motion it is based on correlating similar contrasts. We compared tuning curves for step size and temporal interval for stimuli in which motion information was limited to a single combination of step size and interval. Tuning for step size and temporal interval was highly similar for the two types of motion. Moreover, minimal coherence thresholds for both types of motion matched quantitatively, irrespective of dot density. We also measured sensitivity for so-called no-phi motion stimuli, in which the contrast of displaced dots was set to zero. Sensitivity for no-phi motion was low for stimuli containing only black or only white dots. When both dot polarities were present in the stimulus, sensitivity was absent. Thus, motion information based on separate contrasts was effectively cancelled by a component based on different contrasts. Together these results show equal efficiency in correlating dots of opposite contrast and of similar contrast, which strongly suggests efficient detection of correlations across ON and OFF channels
CHD3 Dissociation on the Kinked Pt(210) Surface: A Comparison of Experiment and Theory
To be able to simulate activated heterogeneously catalyzed reactions on the edge and corner sites of nanoparticles, a method for calculating accurate activation barriers for the reactions is required. We have recently demonstrated that a semiempirical specific reaction parameter (SRP) density functional developed to describe CHD3 dissociation on a flat Ni(111) surface is transferable to describing the same reaction on a stepped Pt(211) surface. In the current work, we compare initial sticking coefficients measured using the King and Wells beam reflectivity technique and calculated from ab initio molecular dynamics trajectories using the same SRP functional for CHD3 dissociation on a kinked Pt(210) surface at a temperature of 650 K. The calculated sticking coefficients overestimate those determined experimentally, with an average energy shift between the two curves of 13.6 kJ/mol, which is over a factor of 3 times higher than the 4.2 kJ/mol limit that defines chemical accuracy. This suggests the SRP functional predicts an activation barrier that is too low for the dissociation on the least coordinated kink atom, which is the site of the lowest energy transition state and where most of the dissociation occurs in the calculations.Article / Letter to editorLIC/ES/Theoretical Chemistr
The role of acquaintanceship in the perception of child behaviour problems
The role of acquaintanceship with the child on reports of child behaviour by different informants was examined within the framework of a general theory of personality judgment. Mothers of referred children and group-care workers rated videotaped behaviour samples of a well known and an unknown child in the clinic. Independent observers also rated the videotapes. In line with the acquaintanceship hypothesis, mothers were found to perceive more behaviour problems than independent observers when rating well known children but not unknown children. Contrary to the acquaintanceship hypothesis, however, the group-care workers in our study reported more behaviour problems than the other informants regardless of their acquaintance with the children. The clinical and methodological implications of these findings are discussed
The Operational Impacts of Chief Supply Chain Officers in Manufacturing Firms
Many firms have elevated their supply chain management decision-making responsibilities through the creation of ‘Chief Supply Chain Officer’ (CSCO) positions. This is widely attributed to the recognition that superior supply chain operations can generate a competitive advantage. Prior studies have found that firms with CSCOs outperform firms without CSCOs along many financial dimensions. However, these prior efforts did not examine the pathways by which these improvements occur. This study addresses this gap in the literature by investigating whether supply chain characteristics of manufacturing firms differ within firms with CSCOs. To explore this, we investigate the relationship between CSCOs and operational dimensions of supply chain performance using data from the 10-year period between 2008 and 2017. We find that the presence of a CSCO in a firm is associated with shorter cash conversion cycles, lower levels of operational slack, and larger buffers of inventory during periods of high market instability
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