Modelling the impact of alternative fare structures on train overcrowding

The Strategic Rail Authority (SRA) provides the backbone to rail regulation in Great Britain. As part of its responsibilities, the SRA monitors overcrowding on trains which it measures in terms of the proportion of passengers on trains in excess of the seat capacity for longer distance services, and with an allowance for standing passengers on shorter journeys of less than 20 minutes. Overcrowding on Britain’s railways fell during the early 1990s but has been on the increase since 1996 with particularly acute problems in the morning peak for services travelling to London. In a study conducted on behalf of the SRA we developed the PRAISE rail operations model to include penalties for overcrowding based upon journey purpose, journey time and degree of overcrowding. Using demand, fares and timetable information for an actual case study route, we examine how fares and ticketing restrictions can be set to manage demand throughout the day without significantly reducing the overall demand for rail travel

LEF2 - A strategic freight transport model for Great Britain.

INTRODUCTION This paper reports some innovative model building that yields a useful addition to models of freight in Great Britain. Currently, the Great Britain Freight Model (GBFM) is part of the Department for Transport's (DtT) national model suite. That model is over-detailed for some purposes and internally only models mode choice effects. Freight modelling requirements in Great Britain were reviewed in work for the DtT, the Strategic Rail Authority (SRA), the Highways Agency (HA) and Transport for London (TfL). Arising from our work on that project, and our involvement with GBFM, we identified a need for a strategic freight transport model, near instantaneous to run, that could handle both the mode choice effects and market size effects of policies. Section 2 of this paper sets out the background to our work. Section 3 introduces the LEeds Freight Transport (LEFT) model series. Section 4 describes the model LEFT2 from that series, and section 5 gives some results using version LEFT2.6. Section 6 lists the plans we currently have for LEFT3, and section 7 concludes

Walking Technicolor and Electroweak Radiative Corrections

We examine the effect of walking technicolor dynamics on the electroweak $S$ parameter and contrast it with the effect of QCD-like technicolor dynamics. Our main tools are the operator product expansion for the high-momentum behavior of the electroweak gauge boson vacuum polarizations and the analyticity of these polarizations which relate their low and high momentum behaviors. We show that whereas in large QCD-like technicolor models $S$ is large and positive, in walking technicolor models a negative contribution is emphasized, related to the large anomalous dimension of the technifermion condensate. Thus in walking technicolor $S$ is determined by a large cancellation of two competing effects. This may result in much smaller values of $S$ than in QCD-like technicolor, although considerable uncertainties are involved. We conclude that it is impossible to rule out walking technicolor based on the present experimental limits on $S$ and the present theoretical technology.Comment: 22 pages (4 figures, available upon request

Resonant Tunneling Between Quantum Hall Edge States

Resonant tunneling between fractional quantum Hall edge states is studied in the Luttinger liquid picture. For the Laughlin parent states, the resonance line shape is a universal function whose width scales to zero at zero temperature. Extensive quantum Monte Carlo simulations are presented for $\nu = 1/3$ which confirm this picture and provide a parameter-free prediction for the line shape.Comment: 14 pages , revtex , IUCM93-00

HI in the Outskirts of Nearby Galaxies

The HI in disk galaxies frequently extends beyond the optical image, and can trace the dark matter there. I briefly highlight the history of high spatial resolution HI imaging, the contribution it made to the dark matter problem, and the current tension between several dynamical methods to break the disk-halo degeneracy. I then turn to the flaring problem, which could in principle probe the shape of the dark halo. Instead, however, a lot of attention is now devoted to understanding the role of gas accretion via galactic fountains. The current $\rm \Lambda$ cold dark matter theory has problems on galactic scales, such as the core-cusp problem, which can be addressed with HI observations of dwarf galaxies. For a similar range in rotation velocities, galaxies of type Sd have thin disks, while those of type Im are much thicker. After a few comments on modified Newtonian dynamics and on irregular galaxies, I close with statistics on the HI extent of galaxies.Comment: 38 pages, 17 figures, invited review, book chapter in "Outskirts of Galaxies", Eds. J. H. Knapen, J. C. Lee and A. Gil de Paz, Astrophysics and Space Science Library, Springer, in pres

Genome-wide association study of peripheral neuropathy with D-drug-containing regimens in AIDS Clinical Trials Group protocol 384.

Stavudine (d4T) was, until recently, one of the most widely prescribed antiretroviral drugs worldwide. While there has been a major shift away from d4T use in resource-limited countries, a large number of patients have previously received (or continue to receive) d4T, and many have developed peripheral neuropathy. The identification of genetic predictors of increased risk might suggest novel therapeutic targets for such patients. In AIDS Clinical Trials Group protocol 384, antiretroviral-naïve patients were randomized to d4T/didanosine (ddI)- or zidovudine/lamivudine-containing regimens. Data from d4T/ddI recipients were analyzed for genome-wide associations (approximately 1 million genetic loci) with new onset distal sensory peripheral neuropathy. Analyses involved 254 patients (49 % White, 34 % Black, 17 % Hispanic), comprising 90 peripheral neuropathy cases (32 grade 1, 35 grade 2, 23 grade 3) and 164 controls. After correcting for multiple comparisons, no polymorphism was consistently associated with neuropathy among all patients, among White, Black, and Hispanic patients analyzed separately, both in genome-wide analyses (threshold, P < 5.0 × 10(-8)) and focused on 46 neuropathy-associated genes (threshold, P < 3.5 × 10(-5)). In the latter analyses, the lowest P values were in KIF1A among Whites (rs10199388, P = 8.4 × 10(-4)), in LITAF among Blacks (rs13333308, P = 6.0 × 10(-6)), and in NEFL among Hispanics (rs17763685, P = 5.6 × 10(-6)). Susceptibility to d4T/ddI-associated neuropathy is not explained by a single genetic variant with a marked effect

A wider Europe? The view from Russia, Belarus and Ukraine

On the evidence of national surveys conducted between 2000 and 2006, there is a declining sense of European self-identity in the three Slavic post-Soviet republics of Russia, Belarus and Ukraine. Attitudes towards the European Union and the possibility of membership are broadly supportive, but with a substantial proportion who find it difficult to express a view, and substantial proportions are poorly informed in comparison with the general public in EU member or prospective member countries. Those who are better informed are more likely to favour EU membership and vice versa. Generally, socioeconomic characteristics (except for age and region) are relatively poor predictors of support for EU membership as compared with attitudinal variables. But ‘Europeanness’ should not be seen as a given, and much will depend on whether EU member countries emphasize what is common to east and west or establish ‘new dividing lines’ in place of those of the cold war

Chitayat syndrome: hyperphalangism, characteristic facies, hallux valgus and bronchomalacia results from a recurrent c.266A>G p.(Tyr89Cys) variant in the ERF gene.

BACKGROUND: In 1993, Chitayat et al., reported a newborn with hyperphalangism, facial anomalies, and bronchomalacia. We identified three additional families with similar findings. Features include bilateral accessory phalanx resulting in shortened index fingers; hallux valgus; distinctive face; respiratory compromise. OBJECTIVES: To identify the genetic aetiology of Chitayat syndrome and identify a unifying cause for this specific form of hyperphalangism. METHODS: Through ongoing collaboration, we had collected patients with strikingly-similar phenotype. Trio-based exome sequencing was first performed in Patient 2 through Deciphering Developmental Disorders study. Proband-only exome sequencing had previously been independently performed in Patient 4. Following identification of a candidate gene variant in Patient 2, the same variant was subsequently confirmed from exome data in Patient 4. Sanger sequencing was used to validate this variant in Patients 1, 3; confirm paternal inheritance in Patient 5. RESULTS: A recurrent, novel variant NM_006494.2:c.266A>G p.(Tyr89Cys) in ERF was identified in five affected individuals: de novo (patient 1, 2 and 3) and inherited from an affected father (patient 4 and 5). p.Tyr89Cys is an aromatic polar neutral to polar neutral amino acid substitution, at a highly conserved position and lies within the functionally important ETS-domain of the protein. The recurrent ERF c.266A>C p.(Tyr89Cys) variant causes Chitayat syndrome. DISCUSSION: ERF variants have previously been associated with complex craniosynostosis. In contrast, none of the patients with the c.266A>G p.(Tyr89Cys) variant have craniosynostosis. CONCLUSIONS: We report the molecular aetiology of Chitayat syndrome and discuss potential mechanisms for this distinctive phenotype associated with the p.Tyr89Cys substitution in ERF

Pre - Inflationary Clues from String Theory ?

"Brane supersymmetry breaking" occurs in String Theory when the only available combinations of D-branes and orientifolds are not mutually BPS and yet do not introduce tree-level tachyon instabilities. It is characterized by the emergence of a steep exponential potential, and thus by the absence of maximally symmetric vacua. The corresponding low-energy supergravity admits intriguing spatially-flat cosmological solutions where a scalar field is forced to climb up toward the steep potential after an initial singularity, and additional milder terms can inject an inflationary phase during the ensuing descent. We show that, in the resulting power spectra of scalar perturbations, an infrared suppression is typically followed by a pre-inflationary peak that reflects the end of the climbing phase and can lie well apart from the approximately scale invariant profile. A first look at WMAP9 raw data shows that, while the chi^2 fits for the low-l CMB angular power spectrum are clearly compatible with an almost scale invariant behavior, they display nonetheless an eye-catching preference for this type of setting within a perturbative string regime.Comment: 34 pages, LaTeX, 16 eps figures. Relative displacement in fig. 14 and some typos corrected, references and acknowledgments updated. To appear in JCA

Answering a Basic Objection to Bang/Crunch Holography

The current cosmic acceleration does not imply that our Universe is basically de Sitter-like: in the first part of this work we argue that, by introducing matter into *anti-de Sitter* spacetime in a natural way, one may be able to account for the acceleration just as well. However, this leads to a Big Crunch, and the Euclidean versions of Bang/Crunch cosmologies have [apparently] disconnected conformal boundaries. As Maldacena and Maoz have recently stressed, this seems to contradict the holographic principle. In the second part we argue that this "double boundary problem" is a matter not of geometry but rather of how one chooses a conformal compactification: if one chooses to compactify in an unorthodox way, then the appearance of disconnectedness can be regarded as a *coordinate effect*. With the kind of matter we have introduced here, namely a Euclidean axion, the underlying compact Euclidean manifold has an unexpectedly non-trivial topology: it is in fact one of the 75 possible underlying manifolds of flat compact four-dimensional Euclidean spaces.Comment: 29 pages, 3 figures, added references and comparison with "cyclic" cosmology, JHEP versio