The molecular condensations ahead of Herbig-Haro objects. II: a theoretical investigation of the HH 2 condensation

Clumps of enhanced molecular emission are present close to a number of Herbig-Haro (HH) objects. These enhancements may be the consequence of an active photochemistry driven by the UV radiation originating from the shock front of the HH object. On the basis of this picture and as a follow up to a molecular line survey toward the quiescent molecular clump ahead of the HH object, HH 2 (Girart et al. 2002), we present a detailed time and depth dependent chemical model of the observed clump. Despite several difficulties in matching the observations, we constrain some of the physical and chemical parameters of the clump ahead of HH 2. In particular, we find that the clump is best described by more than one density component with a peak density of 3 × 105 cm-3 and a visual extinction of ≤3.5 mag; its lifetime can not be much higher than 100 years and the impinging radiation is enhanced with respect to the ambient one by probably no more than 3 orders of magnitude. Our models also indicate that carbon-bearing species should not completely hydrogenate as methane when freezing out on grains during the formation of the clump

Applications in Macroeconometrics

The title of this work, Applications in Macroeconometrics, reflects the unifying theme of my essays: new, and original research in applied macroeconomics, and applied econometrics. This dissertation consists of three chapters specifically looking at producer price inflation pass-through, technical progress, and moral hazard in United States critical banking markets. My first chapter seeks to quantify the pass-through (PT) and causal direction of producer to consumer prices. We further disaggregate PPI down to commodity-specific indices to quantify disaggregated PPI PT coefficients. By estimating an augmented Phillips Curve, we find short-run PT of aggregate PPI to be around 7 percent. Using a VARX framework, we conduct Toda-Yamamoto tests that show evidence of bidirectional causality between CPI and PPI inflation. When disaggregating down to commodity-specific indices, we find several PPI series that exhibit unidirectional causality and express stronger pass-through coefficients than aggregate PPI. My second chapter (coauthored with Scott Schuh and Brad Humphreys) expands a niche literature that argues how technical progress and productivity growth--which are ordinarily arduous to measure--can be expressed in athletic outcomes. In particular, we formalize the link between race outcomes, and total factor productivity (TFP) using deterministic and stochastic trend econometric models. A bivariate error-correction model reveals evidence that race outcomes and TFP share a common trend, and that race outcomes adjust to TFP but not vice versa. These results suggest aggregate technological progress partially diffuses to firms and industries, and motivates further investigation of the underlying structural relationships. My third chapter contributes new evidence to the literatures on banking performance, and too-big-to-fail (TBTF) in US banking. We estimate a restricted translog semiparametric smooth coefficient seemingly unrelated regressions model (SPSC SUR), wherein model elasticities are functions of nonperforming assets, a proxy for moral hazard, to derive nonperformance-adjusted returns-to-scale estimates for critical market banks from 2001 through 2021. Over our full sample, the median critical market bank tends to operate under increasing returns-to-scale while half of all critical market banks exhibit slight decreasing returns-to-scale. Results taken over the past two decades suggest that most TBTF banks have exhausted their economies of scale concurrent with the shrinking competitive landscape

A pilot effectiveness study of the Enhancing Parenting Skills (EPaS) 2014 programme for parents of children with behaviour problems: study protocol for a randomised controlled trial

BACKGROUND: The Enhancing Parenting Skills (EPaS) 2014 programme is a home-based, health visitor-delivered parenting support programme for parents of children with identified behaviour problems. This trial aims to evaluate the effectiveness of the EPaS 2014 programme compared to a waiting-list treatment as usual control group. METHODS/DESIGN: This is a pragmatic, multicentre randomised controlled trial. Sixty health visitors will each be asked to identify two families that have a child scoring above the clinical cut-off for behaviour problems using the Eyberg Child Behaviour Inventory (ECBI). Families recruited to the trial will be randomised in a 1:1 ratio into an intervention or waiting-list control group. Randomisation will occur within health visitor to ensure that each health visitor has one intervention family and one control family. The primary outcome is change in child behaviour problems as measured by the parent-reported ECBI. Secondary outcomes include other measures of child behaviour, parent behaviour, and parental depression as measured by parent-reports and an independent observation of parent and child behaviour. Follow-up measures will be collected 6-months after the collection of baseline measures. DISCUSSION: This is the first rigorous evaluation of the EPaS 2014 programme. The trial will provide important information on the effectiveness of a one-to-one home-based intervention, delivered by health visitors, for pre-school children with behaviour problems. It will also examine potential mediating (improved parent behaviour and/or improved parental depression) and moderating (single parent, teenage parent, poverty, low education level) factors. TRIAL REGISTRATION: Current Controlled Trials ISRCTN06867279 (18 June 2014

Who should pay for interdependent risk? Policy implications for security interdependence among airports

We study interdependent risks in security, and shed light on the economic and policy implications of increasing security interdependence in presence of reactive attackers. We investigate the impact of potential public policy arrangements on the security of a group of interdependent organizations, namely, airports. Focusing on security expenditures and costs to society, as assessed by a social planner, to individual airports and to attackers, we first develop a game‐theoretic framework, and derive explicit Nash equilibrium and socially optimal solutions in the airports network. We then conduct numerical experiments mirroring real‐world cyber scenarios, to assess how a change in interdependence impact the airports' security expenditures, the overall expected costs to society, and the fairness of security financing. Our study provides insights on the economic and policy implications for the United States, Europe, and Asia

Critical properties of loop percolation models with optimization constraints

We study loop percolation models in two and in three space dimensions, in which configurations of occupied bonds are forced to form closed loop. We show that the uncorrelated occupation of elementary plaquettes of the square and the simple cubic lattice by elementary loops leads to a percolation transition that is in the same universality class as the conventional bond percolation. In contrast to this an optimization constraint for the loop configurations, which then have to minimize a particular generic energy function, leads to a percolation transition that constitutes a new universality class, for which we report the critical exponents. Implication for the physics of solid-on-solid and vortex glass models are discussed.Comment: 8 pages, 8 figure

Public health economics: a systematic review of guidance for the economic evaluation of public health interventions and discussion of key methodological issues

BACKGROUND: If Public Health is the science and art of how society collectively aims to improve health, and reduce inequalities in health, then Public Health Economics is the science and art of supporting decision making as to how society can use its available resources to best meet these objectives and minimise opportunity cost. A systematic review of published guidance for the economic evaluation of public health interventions within this broad public policy paradigm was conducted. METHODS: Electronic databases and organisation websites were searched using a 22 year time horizon (1990–2012). References of papers were hand searched for additional papers for inclusion. Government reports or peer-reviewed published papers were included if they; referred to the methods of economic evaluation of public health interventions, identified key challenges of conducting economic evaluations of public health interventions or made recommendations for conducting economic evaluations of public health interventions. Guidance was divided into three categories UK guidance, international guidance and observations or guidance provided by individual commentators in the field of public health economics. An assessment of the theoretical frameworks underpinning the guidance was made and served as a rationale for categorising the papers. RESULTS: We identified 5 international guidance documents, 7 UK guidance documents and 4 documents by individual commentators. The papers reviewed identify the main methodological challenges that face analysts when conducting such evaluations. There is a consensus within the guidance that wider social and environmental costs and benefits should be looked at due to the complex nature of public health. This was reflected in the theoretical underpinning as the majority of guidance was categorised as extra-welfarist. CONCLUSIONS: In this novel review we argue that health economics may have come full circle from its roots in broad public policy economics. We may find it useful to think in this broader paradigm with respect to public health economics. We offer a 12 point checklist to support government, NHS commissioners and individual health economists in their consideration of economic evaluation methodology with respect to the additional challenges of applying health economics to public health

Hybrid and Exotic Mesons from FLIC Fermions

The spectral properties of hybrid meson interpolating fields are investigated. The quantum numbers of the meson are carried by smeared-source fermion operators and highly-improved chromo-electric and -magnetic field operators composed with APE-smeared links. The effective masses of standard and hybrid operators indicate that the ground state meson is effectively isolated using both standard and hybrid interpolating fields. Focus is placed on interpolating fields in which the large spinor components of the quark and antiquark fields are merged. In particular, the effective mass of the exotic $1^{-+}$ meson is reported. Further, we port some values for excited mesonic states using a variational process.Comment: 3 Pages, 3 figures, Lattice2003(Spectrum

Allozyme Electrophoretic Methods for Analysing Genetic Variation in Giant Clams (Tridacnidae)

Resource /Energy Economics and Policy,

A vortex description of the first-order phase transition in type-I superconductors

Using both analytical arguments and detailed numerical evidence we show that the first order transition in the type-I 2D Abelian Higgs model can be understood in terms of the statistical mechanics of vortices, which behave in this regime as an ensemble of attractive particles. The well-known instabilities of such ensembles are shown to be connected to the process of phase nucleation. By characterizing the equation of state for the vortex ensemble we show that the temperature for the onset of a clustering instability is in qualitative agreement with the critical temperature. Below this point the vortex ensemble collapses to a single cluster, which is a non-extensive phase, and disappears in the absence of net topological charge. The vortex description provides a detailed mechanism for the first order transition, which applies at arbitrarily weak type-I and is gauge invariant unlike the usual field-theoretic considerations, which rely on asymptotically large gauge coupling.Comment: 4 pages, 6 figures, uses RevTex. Additional references added, some small corrections to the tex