7,169 research outputs found
Segmentation of the Travel Market in London: Estimates of Elasticities and Values of Travel Time.
This paper reports background research carried out for an ESRC funded research project entitled "Assessing the Benefits and Incidence of Road Pricing in London". The first two stages of this work are reported here. The first stage was to segment the market for car use in Central and Inner London according to the salient characteristics of users. The second stage was to make estimates of the range of probable values of time and elasticities for each segment of the market using secondary data. A thorough literature search was undertaken and we have liaised with other relevant work in progress.
The results of our distillation of what we have found/borrowed are given in section 3. Own price elasticities of demand are presented disaggregated by mode and journey purpose. In the case of car, latest evidence emerging from the DoT study of road pricing in London has been included, showing how elasticities might be expected to rise as the toll is increased radically such as to have severe `income effects'. Values of Time are presented disaggregated by mode, journey purpose and household income group. There is a difficulty, however, in using these values in mode choice transport models and this is discussed in Section 4. Section 5 presents conclusions and discusses application of the results of this paper in the ESRC project. Section 6 lists references and Section 7 is an Appendix containing brief highlights from many of the source articles consulted in our literature review
Road Pricing: The Potential for Comparative Monitoring. A Report to the London Planning Advisory Committee.
This study was designed to review the proposals for road user charging in the Randstad, Stockholm, Oslo and Singapore, to determine the intentions for monitoring of each of these proposed schemes, to assess the implications for the development of policy in London, and to identify any opportunities for obtaining experience which would help in clarifying the uncertainties associated with proposals for road pricing in London. The study reviewed the objectives and operational requirements for road pricing in London and the criticisms levelled against such proposals. On this basis it developed a series of requirements for monitoring and information gathering to help clarify the outstanding uncertainties. These were used as a check list for a series of discussions with those responsible for proposals in the case study cities. Discussions indicated that the proposals in most cities had changed markedly in the period since the study was commissioned. These changes, and the resulting nature of the proposals, meant that only the proposals for Stockholm were sufficiently similar to those in London to justify collaborative monitoring. The report recommends that such collaboration be developed. However, both the Randstad and Oslo schemes offer the opportunity for obtaining information on actual or predicted user response, while the Singapore proposals will provide valuable experience of new technology. It is recommended that all of these are pursued. The discussions highlighted several lessons of direct relevance to the development of policy in London. In particular it is seen as important to keep the specification of the measures simple; to pursue extensive consultation with those who might be affected and with all political parties and government bodies who might be involved in policy decisions; to provide clear guidance on the anticipated uses of the revenue: and to develop a system which is implemented flexibly, so that problems can be remedied as they arise.
In this context, the role of assessment and monitoring is limited. It should not be used to delay decisions; however, once a commitment is made to proceed, experience from elsewhere will be of value in informing the consultations. A carefully designed monitoring programme will be important in assessing and enhancing a scheme once implemented. It is recommended that the monitoring programme should be based on the requirements identified in this report
Alien Registration- Sherwood, Cline N. (Randolph, Kennebec County)
https://digitalmaine.com/alien_docs/17244/thumbnail.jp
Analogy of the slow dynamics between the supercooled liquid and the supercooled plastic crystal states of difluorotetrachloroethane
Slow dynamics of difluorotetrachloroethane in both supercooled plastic
crystal and supercooled liquid states have been investigated from Molecular
Dynamics simulations. The temperature and wave-vector dependence of collective
dynamics in both states are probed using coherent dynamical scattering
functions . Our results confirm the strong analogy between molecular
liquids and plastic crystals for which -relaxation times and
non-ergodicity parameters are controlled by the non trivial static correlations
as predicted by the Mode Coupling Theory. The use of infinitely thin
needles distributed on a lattice as model of plastic crystals is discussed
Onset of slow dynamics in difluorotetrachloroethane glassy crystal
Complementary Neutron Spin Echo and X-ray experiments and Molecular Dynamics
simulations have been performed on difluorotetrachloroethane (CFCl2-CFCl2)
glassy crystal. Static, single-molecule reorientational dynamics and collective
dynamics properties are investigated. The orientational disorder is
characterized at different temperatures and a change in nature of rotational
dynamics is observed. We show that dynamics can be described by some scaling
predictions of the Mode Coupling Theory (MCT) and a critical temperature
is determined. Our results also confirm the strong analogy between
molecular liquids and plastic crystals for which -relaxation times and
non-ergodicity parameters are controlled by the non trivial static correlations
as predicted by MCT
Recommended from our members
Individual Differences in the Programming of Rapid Bimanual Movements: Are Two Modes Better Than One?
International Journal of Exercise Science 9(3): 347-358, 2016. One of the challenges in performing simultaneous bimanual movements is to prevent interference from one limb to the other, thereby maintaining spatial accuracy in both limbs. Prior research has shown that when a longer distance movement is performed with a shorter movement, the shorter movement overshoots its target and the longer movement undershoots its target relative to control conditions where two shorter or two longer movements are made. The current experiment investigated the motor control strategies used by participants when performing simultaneous aiming movements combining both different and same distances. Participants (N = 20) made rapid lever-positioning movements (goal time to reversal was 350 ms) in the sagittal plane to 2 different spatial targets (20° and 60°) or the same targets (either 20° or 60°). Feedback about spatial accuracy was provided immediately after each trial. Constant error (CE) was measured for each distance based on 20 practice trials per condition. The CE from the same- and different-distance conditions were compared with separate one-way ANOVAs with repeated measures. Overshooting was shown of the 20° target and undershooting of the 60° target when the two distances were performed together. However, the movement amplitudes were positively correlated over trials in both the same- and different-distance conditions. A trial-by-trial analysis of the CE scores revealed both compensatory and non-compensatory strategies. The results suggest individual differences in how amplitude parameters are chosen for use with the generalized motor program in the control of bimanual aiming movements
Paracetamol-induced liver injury modelled in Xenopus laevis embryos
Introduction: Failure to predict drug-induced liver injury (DILI) remains a major contributing factor to lead compound drop-out during drug development. Xenopus embryos are amenable for early stage medium throughput small molecule screens and so have the potential to be used in pre-clinical screens. To begin to assess the usefulness and limitations of Xenopus embryos for safety assessment in the early phases of drug development, paracetamol was used as a model hepatotoxin. Paracetamol overdose is associated with acute liver injury. In mammals, the main mechanism of paracetamol-induced acute liver injury is an increased amount of the reactive metabolite N-acetyl-p-benzoquinone imine (NAPQI) combined with a reduction of free glutathione (GSH). Humans that have taken an overdose of paracetamol are often treated with N-acetyl cysteine (NAC). Method: Xenopus laevis embryos were treated with up to 5 mM paracetamol from stage 38 to stage 45 during development, when the liver is functional. The presence of paracetamol-induced liver injury was assessed by: (Dart et al., 2006) microRNA-122 (miR-122) expression (a hepatic marker), (Jaeschke, 2015) free GSH concentration (a marker of oxidative stress) and (Larson et al., 2005) NAC antioxidant intervention. Results: The amount of free GSH decreased significantly in embryos exposed to increasing paracetamol concentration. In embryos exposed to 5 mM paracetamol, 22.57 ± 4.25 nmol/mg GSH was detected compared to 47.11 ± 7.31 nmol/mg untreated embryos (mean ± SEM). In tail tissue, miRNA-122 expression increased 6.3-fold with 3 mM paracetamol concentration treatment compared to untreated embryos. NAC treatment altered the free GSH decline for embryos treated with up to 5 mM. Embryos exposed to 1 mM paracetamol and then exposed to 0.5 mM NAC 24 h prior to harvest, had an significantly higher amount GSH compared to embryos that were only exposed to 1 mM paracetamol (mean ± SEM; 97.1 ± 9.6 nmol/mg and 54.5 ± 6.6 nmol/mg respectively). Conclusion: Xenopus laevis embryos exhibit similar characteristics of paracetamol-induced liver injury observed in mammalian models. These data indicate that the Xenopus embryo could be a useful in vivo model to assess DILI and aid lead compound prioritisation during the early phase of drug development, in combination with pre-clinical in vitro studies. Consequently, the Xenopus embryo could contribute to the reduction principle as defined by the National Centre for the Replacement, Refinement and Reduction of Animals in Research
Sodium p-nitrophenolate tetrahydrate
The structure of sodium p-nitrophenolate tetrahydrate,
Na+�C6H4NO3
-�4H2O, is presented. The nature of the
hydrogen and coordination bonds in this structure is discussed
and compared with that of sodium p-nitrophenolate dihydrate
- …