[Obituary] Tracey Banivanua Mar, 1974-2017

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Food Superstores, Food Deserts and Traffic Generation in the UK: A Semi-Parametric Regression Approach

This study contributes another route towards explaining and tackling ‘food desert’ effects. It features the estimation of a (semi-parametric) trip attraction model for food superstores in the UK using a composite dataset. The data comprises information from the UK Census of Population, the NOMIS (National Online Manpower Information System) archive and traffic and site-specific data from the TRICS (Trip Rate Information Computer System) databases. The results indicate that traffic to a given food superstore, ceteris paribus, increases with household car ownership, store parking provision, site size (floor space), and distance to the nearest competitor. Furthermore, increases in public transport provision are shown to be associated with increasing car trips. This latter effect is discussed in the light of planning policy for development control purposes and a role linked to the reinforcement of ‘food deserts’. The results also reveal activity-specific household economies of scope and scale. It is suggested how these may also further perpetuate unsustainable development and ‘food desert’ characteristics.Traffic Generation, Food Superstores, Food Deserts, Activity Based Travel, Sustainable Development, Modelling

Transportation Oil Demand Consumer Preferences and Asymmetric Price Responses: Some UK Evidence

The aim of this paper is to (i) establish the role of asymmetric price decompositions in UK road transportation fuel demand, (ii) make explicit the impact of the underlying energy demand trend and (iii) disaggregate the estimation for gasoline and diesel demand as separate commodities. Dynamic UK transport oil demand functions are estimated using the Seemingly Unrelated Structural Time Series Model with decomposed prices to allow for asymmetric price responses. The importance of starting with a flexible modelling approach that incorporates both an underlying demand trend and asymmetric price response function is highlighted. Furthermore, these features can lead to different insights and policy implications than might arise from a model without them. As an example, a zero elasticity for a price-cut is found (for both gasoline and diesel) implying that price reductions do not induce demand for road transportation fuel in the UK. The paper illustrates the importance of joint modelling of gasoline and diesel demand incorporating both asymmetric price responses and stochastic underlying energy demand trends.Diesel; Asymmetry; Price; Underlying Energy Demand Trend (UEDT).

A Storm in a "T" Cup

We revisit the process of transversification and agglomeration of particle momenta that are often performed in analyses at hadron colliders, and show that many of the existing mass-measurement variables proposed for hadron colliders are far more closely related to each other than is widely appreciated, and indeed can all be viewed as a common mass bound specialized for a variety of purposes.Comment: 3 pages, 2 figures, presented by K.C. Kong at the 19th Particles and Nuclei International Conference, PANIC 2011, MIT, Cambridge, MA (July 24-29, 2011

m_T2 : the truth behind the glamour

We present the kinematic variable, m_T2, which is in some ways similar to the more familiar `transverse-mass', but which can be used in events where two or more particles have escaped detection. We define this variable and describe the event topologies to which it applies, then present some of its mathematical properties. We then briefly discuss two case studies which show how m_T2 is vital when reconstructing the masses of supersymmetric particles in mSUGRA-like and AMSB-like scenarios at the Large Hadron Collider

Defective spermatogenesis: Martin et al. respond

This is an Open Access article - Copyright @ National Institute of Environmental Health Science.BACKGROUND: Male reproductive tract abnormalities such as hypospadias and cryptorchidism, and testicular cancer have been proposed to comprise a common syndrome together with impaired spermatogenesis with a common etiology resulting from the disruption of gonadal development during fetal life, the testicular dysgenesis syndrome (TDS). The hypothesis that in utero exposure to estrogenic agents could induce these disorders was first proposed in 1993. The only quantitative summary estimate of the association between prenatal exposure to estrogenic agents and testicular cancer was published over 10 years ago, and other systematic reviews of the association between estrogenic compounds, other than the potent pharmaceutical estrogen diethylstilbestrol (DES), and TDS end points have remained inconclusive. OBJECTIVES: We conducted a quantitative meta-analysis of the association between the end points related to TDS and prenatal exposure to estrogenic agents. Inclusion in this analysis was based on mechanistic criteria, and the plausibility of an estrogen receptor (ER)-α–mediated mode of action was specifically explored. RESULTS: We included in this meta-analysis eight studies investigating the etiology of hypospadias and/or cryptorchidism that had not been identified in previous systematic reviews. Four additional studies of pharmaceutical estrogens yielded a statistically significant updated summary estimate for testicular cancer. CONCLUSIONS: The doubling of the risk ratios for all three end points investigated after DES exposure is consistent with a shared etiology and the TDS hypothesis but does not constitute evidence of an estrogenic mode of action. Results of the subset analyses point to the existence of unidentified sources of heterogeneity between studies or within the study population

Inactivation of cloned Na channels expressed in Xenopus oocytes

This study investigates the inactivation properties of Na channels expressed in Xenopus oocytes from two rat IIA Na channel cDNA clones differing by a single amino acid residue. Although the two cDNAs encode Na channels with substantially different activation properties (Auld, V. J., A. L. Goldin, D. S. Krafte, J. Marshall, J. M. Dunn, W. A. Catterall, H. A. Lester, N. Davidson, and R. J. Dunn. 1988. Neuron. 1:449-461), their inactivation properties resemble each other strongly but differ markedly from channels induced by poly(A+) rat brain RNA. Rat IIA currents inactivate more slowly, recover from inactivation more slowly, and display a steady-state voltage dependence that is shifted to more positive potentials. The macroscopic inactivation process for poly(A+) Na channels is defined by a single exponential time course; that for rat IIA channels displays two exponential components. At the single-channel level these differences in inactivation occur because rat IIA channels reopen several times during a depolarizing pulse; poly(A+) channels do not. Repetitive stimulation (greater than 1 Hz) produces a marked decrement in the rat IIA peak current and changes the waveform of the currents. When low molecular weight RNA is coinjected with rat IIA RNA, these inactivation properties are restored to those that characterize poly(A+) channels. Slow inactivation is similar for rat IIA and poly(A+) channels, however. The data suggest that activation and inactivation involve at least partially distinct regions of the channel protein

Polymerisable surfactants for polymethacrylates using catalytic chain transfer polymerisation (CCTP) combined with sulfur free-RAFT in emulsion polymerisation

Statistical copolymers of methacrylic acid and methyl methacrylate were synthesised via free radical catalytic chain transfer polymerisation (CCTP) in emulsion to form a hydrophilic emulsifier/surfactant. The vinyl-terminated oligomers were in turn utilised as chain transfer agents, with no further purification, for the formation of diblock copolymers with butyl and methyl methacrylate which constitutes the emulsifier via sulfur-free reversible addition–fragmentation chain transfer polymerisation (SF-RAFT). In turn these polymers were solubilized with various concentrations of ammonium hydroxide and utilised in the surfactant-free emulsion polymerization of butyl methacrylate using persulfate initiators, which also stabilized the polymer particles with observed no coagulation, with solid contents as high as 40%

Finding Higgs bosons heavier than 2 m_W in dileptonic W-boson decays

We reconsider observables for discovering a heavy Higgs boson (with m_h > 2m_W) via its di-leptonic decays h -> WW -> l nu l nu. We show that observables generalizing the transverse mass that take into account the fact that both of the intermediate W bosons are likely to be on-shell give a significant improvement over the variables used in existing searches. We also comment on the application of these observables to other decays which proceed via narrow-width intermediates.Comment: v1:4 pages, 1 figure; v2: 6 pages, 2 figures, substantially revise