516 research outputs found
Forecasting inflation with thick models and neural networks
This paper applies linear and neural network-based āthickā models for forecasting inflation based on Phillipsācurve formulations in the USA, Japan and the euro area. Thick models represent ātrimmed meanā forecasts from several neural network models. They outperform the best performing linear models for āreal-timeā and ābootstrapā forecasts for service indices for the euro area, and do well, sometimes better, for the more general consumer and producer price indices across a variety of countries. JEL Classification: C12, E31bootstrap, Neural Networks, Phillips Curves, real-time forecasting, Thick Models
Negotiating the real: Culture and fantastical fiction 1843-1973
This dissertation examines the growth and practice of two distinct reading techniques, with reference to fantastical fiction from Ń 843 to 1973. While acknowledging that specific reading practices are not exclusive to particular groups or individuals, it is proposed, broadly, that readers fall into two categories: those who tend to be distanced from the text and approach it analytically; those who tend to embrace the text and immerse themselves in its narrative. These two groups, critical readers and experience readers, have their reading habits determined by basic philosophical assumptions. One aim of the dissertation is to explore the link between this division and divisions within the literary hierarchy, articulating a methodology/typology of reading. Criticism of texts in this dissertation involves discussion of the above hypothesis, assessing the value assigned to literary works by each group of reader and considering how the texts themselves investigate the hypothesis. Various theories and critical concepts are engaged with, including those of Marxist aesthetics, psychoanalysis, liberal humanism, cultural studies, and postmodernism. The aim is to demonstrate the practice of both reading techniques and to draw conclusions concerning their respective psychological and social significance. The dissertation argues that fantastical fiction is often a site of interaction between such binary opposites as realism/fantasy, high/popular, ideas/escape, and polemic/amusing. The struggle between these opposites may provide a dialectic of ''critical'" and ''experience" reading
Quantifying and sustaining welfare gains from monetary commitment
The objectives of this paper are: first, to quantify the stabilization welfare gains from commitment; second, to examine how commitment to an optimal rule can be sustained as an equilibrium and third, to find a simple interest rate rule that closely approximates the optimal commitment one. We utilize an influential empirical micro-founded DSGE model, the euro area model of Smets and Wouters (2003), and a quadratic approximation of the representative householdās utility as the welfare criterion. Importantly, we impose the effect of a nominal interest rate zero lower bound. In contrast with previous studies, we find significant stabilization gains from commitment: our central estimate is a 0.4 - 0.5% equivalent permanent increase in consumption, but in a variant with a higher degree of price stickiness, gains of over 2% are found. We also find that a simple optimized commitment rule with the nominal interest rate responding to current inflation and the real wage closely mimics the optimal rule. JEL Classification: E52, E37, E58commitment, discretion, Monetary rules, welfare gains
Happiness Inertia: Analytical Aspects of the Easterlin Paradox
Using a New-Keynesian flexi-price model with external habit formation in consumption and labor supply, we identify the channels underlying the Easterlin Paradox (or āHappiness Inertiaā, its generalization). These include whether external habit formation is in ādifferenceā or āratioā form; the growth and convexity characteristics of non-pecuniary effects; and the nature of risk aversion. We show that the impact of labor habit formation on welfare can (unlike consumption) be positive or negative. The form of habit formation (rather than habit per se) is a key determinant of whether welfare functions reproduce happiness inertia; only when habit is modelled in ratio form, does this possibility open up. The model thus bridges the gap between theoretical models and social policy, pecuniary and non-pecuniary motives.Efficiency wage; Unemployment; Regional growth.
Risk Management in Action. Robust monetary policy rules under structured uncertainty.
Recent interest in āRisk Managementā has highlighted the relevance of Bayesian analysis for robust monetary- policy making. This paper sets out a comprehensive methodology for designing policy rules inspired by such considerations. We design rules that are robust with respect to model uncertainty facing both the policy-maker and private sector. We apply our methodology to three simple interest-rate rules: inflation-forecast- based (IFB) rules with a discrete forward horizon, one targeting a discounted sum of forward inflation, and a current wage inflation rule. We use an estimated DSGE model of the euro area and estimated measures of structured exogenous and parameter uncertainty for the exercise. We find that IFB rules with a long horizon perform poorly with or without robust design. Our discounted future targeting rule performs much better, indicating that policy can be highly forward-looking without compromising stabilization. The wage inflation rule dominates whether it is designed to have good robust properties or not. JEL Classification: E52, E37, E58Interest-rate rules, Robustness, structured uncertainty
Population analysis of bacterial pathogens on distinct temporal and spatial scales
Bacteria have been the causative agents of major infectious disease pandemics
throughout human history. Over the past 4 decades, a combination of changing
medical practices, industrialization, and globalisation have led to a number of
emergences and re-emergences of bacterial pathogens. The design of rational control
programs and bespoke therapies will require an enhanced understanding of the
dynamics underpinning the emergence and transmission of pathogenic clones. The
recent development of new technologies for sequencing bacterial genomes rapidly
and economically has led to a greatly enhanced understanding of the diversity of
bacterial populations.
This thesis describes the application of whole genome sequencing of 2 bacterial
pathogens, Staphylococcus aureus and Legionella pneumophila, in order to
understand the dynamics of bacterial infections on different temporal and spatial
scales. The first study involves the examination of S. aureus evolution during a
chronic infection of a single patient over a period of 26 months revealing differences
in antibiotic resistance profiles and virulence factor expression over time. The
genetic variation identified correlated with differences in growth rate, haemolytic
activity, and antibiotic sensitivity, implying a profound effect on the ecology of S.
aureus. Importantly, polymorphisms were identified in global regulators of
virulence, with a high frequency of polymorphisms within the SigB locus identified,
suggesting this region may be under selection in this patient. The identification of
genes under diversifying selection during long-term infection may inform the design
of novel therapeutics for the control of refractory chronic infections.
Secondly, the emergence and transmission of 3 pandemic lineages derived from S.
aureus clonal complex 30 (CC30) were investigated. Independent origins for each
pandemic lineage were identified, with striking molecular correlates of hospital- or
community-associated pandemics represented by mobile genetic elements, such as
bacteriophage and Staphylococcal pathogenicity islands, and non-synonymous
mutations affecting antibiotic resistance and virulence. Hospitals in large cities were
identified as hubs for the transmission of MRSA to regional health care centres. In
addition, comparison of whole genome sequences revealed that at least 3
independent acquisitions of TSST-1 have occurred in CC30, but a single distinct
clade of diverse community-associated CC30 strains was responsible for the TSS
epidemic of the late 1970s, and for subsequent cases of TSS in the UK and USA.
Finally, whole genome sequencing was used as a tool for investigating a recent
outbreak of legionellosis in Edinburgh. An unexpectedly high level of genomic
diversity was identified among the outbreak strains, with respect to core genome
polymorphisms, and accessory genome content. The data indicate that affected
individuals may be infected with heterogeneous strains. The findings highlight the
complexities in identifying environmental sources and suggest possible differences
in pathogenic potential among isolates from a single outbreak.
Taken together, the findings demonstrate applications of bacterial genome
sequencing leading to enhanced understanding of bacterial pathogen evolution,
emergence, and transmission, which may ultimately inform appropriate infection
control measures
The acceleration dilemma : can English law accommodate constructive acceleration?
Purpose
ā The aim of this paper is to explore the hypothesis that a contractor is entitled to payment for āconstructiveā acceleration implemented to avoid liquidated damages when denied a warranted time extension request by the employer or certifier under an English law construction contract. This claim is recognised in the US legal system, but not elsewhere.
Design/methodology/approach
ā This paper adopts a āblack letterā approach to reviewing the claim of constructive acceleration within the context of English and Commonwealth case law, from the perspective of a claimant contractor.
Findings
ā The research presented in this paper concludes that whilst claims for constructive acceleration are unlikely to succeed in an English court on the basis of US law, a claim might be supportable on more orthodox common law grounds. These include implied instructions under the contract, breach of the contract based on the employer or certifierās failure to operate the contract, mitigation of damages, unjust enrichment and tortious intimidation.
Research limitations/implications
ā The focus of this paper is placed on English, Unites States, Canadian and Australasian case law.
Practical implications
ā The range of potential legal grounds for constructive acceleration examined in this paper provides a toolkit for practitioners preparing to make or defend constructive acceleration claims. This paper also bring more clarity to a potential legal problem faced by practitioners in circumstances of significant tension and limited time.
Originality/value
ā This paper provides a useful information source for practitioners faced with the prospect of advancing or defending constructive acceleration claims, and it provides a foundation for future related studies examining a wider scope of jurisdictions
Land use change and soil carbon pools: Evidence from a long-term silvopastoral
Multi-functional silvopastoral systems provide a wide range of services to human society including the regulation of nutrients and water in soils and the sequestration of atmospheric carbon dioxide (CO2). Although silvopastoral systems significantly contribute to enhance aboveground carbon (C) sequestration (e.g. C accumulation in woody plant biomass), their long-term effects on soil C pools are less clear. In this study we performed soil physical fractionation analyses to quantify the C pool of different aggregate fractions across three land use types including (1) silvopastoral system with ash trees (Fraxinus excelsior L.), (2) planted woodland with ash trees, and (3) permanent grassland, which were established in 1989 at Loughgall, Northern Ireland, UK. Our results show that 26 years after the conversion of permanent grassland to either silvopastoral or woodland systems, soil C (and N) stocks (0ā20 cm depth) did not significantly change between the three land use types. We found, however, that permanent grassland soils were associated with significantly higher C pools (g C kgā1 soil; P 2 mm) whereas soil C pools of the micro-aggregate (53ā250 Ī¼m) and silt and clay (< 53 Ī¼m) fractions were significantly higher in the silvopastoral and woodland systems (P < 0.05). A key finding of this study is that while tree planting on permanent grassland may not contribute to greater soil C stocks it may, in the long-term, increase the C pool of more stable (recalcitrant) soil micro-aggregate and silt and clay fractions, which could be more resilient to environmental change
Evolved Gas Measurements Planned for the Lower Layers of the Gale Crater Mound with the Sample Analysis at Mars Instrument Suite
The lower mound strata of Gale Crater provide a diverse set of chemical environments for exploration by the varied tools of the Curiosity Rover of the Mars Science Laboratory (MSL) Mission. Orbital imaging and spectroscopy clearly reveal distinct layers of hydrated minerals, sulfates, and clays with abundant evidence of a variety of fluvial processes. The three instruments of the MSL Sample Analysis at aMars (SAM) investigation, the Quadrupole Mass Spectrometer (QMS), the Tunable Laser Spectrometer (TLS), and the Gas Chromatograph (GC) are designed to analyze either atmospheric gases or volatiles thermally evolved or chemically extracted from powdered rock or soil. The presence or absence of organic compounds in these layers is of great interest since such an in situ search for this type of record has not been successfully implemented since the mid-60s Viking GCMS experiments. However, regardless of the outcome of the analysis for organics, the abundance and isotopic composition of thermally evolved inorganic compounds should also provide a rich data set to complement the mineralogical and elemental information provided by other MSL instruments. In addition, these evolved gas analysis (EGA) experiments will help test sedimentary models proposed by Malin and Edgett (2000) and then further developed by Milliken et al (2010) for Gale Crater. In the SAM EGA experiments the evolution temperatures of H2O, CO2, SO2, O2, or other simple compounds as the samples are heated in a helium stream to 1000 C provides information on mineral types and their associations. The isotopic composition of O, H, C, and S can be precisely determined in several evolved compounds and compared with the present day atmosphere. Such SAM results might be able to test mineralogical evidence of changing sedimentary and alteration processes over an extended period of time. For example, Bibring et al (2006) have suggested such a major shift from early nonacidic to later acidic alteration. We will illustrate through a variety of evolved gas experiments implemented under SAM-like gas flow and temperature ramp conditions on terrestrial analog minerals on high fidelity Sam breadboards the type of chemical information we expect SAM to provide
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