2,435 research outputs found
Rethinking the Economics of Land and Housing
Why are house prices in many advanced economies rising faster than incomes? Why isn't land and location taught or seen as important in modern economics? What is the relationship between the financial system and land?
In this accessible but provocative guide to the economics of land and housing, the authors reveal how many of the key challenges facing modern economies - including housing crises, financial instability and growing inequalities - are intimately tied to the land economy. Looking at the ways in which discussions of land have been routinely excluded from both housing policy and economic theory, the authors show that in order to tackle these increasingly pressing issues a major rethink by both politicians and economists is required
Credit policy and the ‘debt shift’ in advanced economies
The decline in the share of bank credit to non-financial firms since the 1990s, relative to credit for real estate and financial asset markets, has raised concerns over economic growth and financial stability and sparked renewed interest in credit policies, instruments and institutions. We examine their theoretical case and post-war use, and trace their demise during the wider market-oriented policy reconfiguration from the 1980s. Notably, this included home ownership polices favouring mortgage markets. We then examine the empirical relationship between credit policy and credit allocation in the 1973–2005 period for 17 advanced economies. Taking account of co-integration, we present evidence that the decline of credit policies is significantly associated with a lower share of lending to non-financial firms. It may be worth revisiting the potential of credit policies to support adequate financing for goals such as innovation, industrial development and the transition to a low-carbon economy
Seigniorage in the 21st Century: A Study of the Profits from Money Creation in the United Kingdom and Denmark
This paper develops a new theory of seigniorage suited to modern economies where the majority of money is created not by the state or central bank but by commercial banks and other monetary financial institutions via their lending activity. We identify four different forms of seigniorage that take account of the modern institutional separation between the state, the central bank, commercial banks and the non-bank private sector in terms of their identities as ‘money creators’ and ‘money users’. The new typology differentiates between seigniorage profits arising from interest rate spreads on stocks of created money and profits arising from flows of interest payments on newly created assets. We illustrate our theoretical framework with empirical data on commercial bank seigniorage and related variables in the United Kingdom and the Denmark over the past quarter century
Multifactor Dimensionality Reduction Reveals a Three-Locus Epistatic Interaction Associated with Susceptibility to Pulmonary Tuberculosis
Background:
Identifying high-order genetics associations with non-additive (i.e. epistatic) effects in population-based studies of common human diseases is a computational challenge. Multifactor dimensionality reduction (MDR) is a machine learning method that was designed specifically for this problem. The goal of the present study was to apply MDR to mining high-order epistatic interactions in a population-based genetic study of tuberculosis (TB). Results:
The study used a previously published data set consisting of 19 candidate single-nucleotide polymorphisms (SNPs) in 321 pulmonary TB cases and 347 healthy controls from Guniea-Bissau in Africa. The ReliefF algorithm was applied first to generate a smaller set of the five most informative SNPs. MDR with 10-fold cross-validation was then applied to look at all possible combinations of two, three, four and five SNPs. The MDR model with the best testing accuracy (TA) consisted of SNPs rs2305619, rs187084, and rs11465421 (TA = 0.588) in PTX3, TLR9 and DC-Sign, respectively. A general 1000-fold permutation test of the null hypothesis of no association confirmed the statistical significance of the model (p = 0.008). An additional 1000-fold permutation test designed specifically to test the linear null hypothesis that the association effects are only additive confirmed the presence of non-additive (i.e. nonlinear) or epistatic effects (p = 0.013). An independent information-gain measure corroborated these results with a third-order epistatic interaction that was stronger than any lower-order associations. Conclusions:
We have identified statistically significant evidence for a three-way epistatic interaction that is associated with susceptibility to TB. This interaction is stronger than any previously described one-way or two-way associations. This study highlights the importance of using machine learning methods that are designed to embrace, rather than ignore, the complexity of common diseases such as TB. We recommend future studies of the genetics of TB take into account the possibility that high-order epistatic interactions might play an important role in disease susceptibility
Predatory impact of the myctophid fish community on zooplankton in the Scotia Sea (Southern Ocean)
Myctophids are the most abundant mesopelagic fishes in the Southern Ocean, although their trophic role within the predominantly krill-based food web in regions south of the Antarctic Polar Front (APF) is poorly resolved. This study therefore examined the diets of 10 species of myctophid fishes: Electrona antarctica, E. carlsbergi, Gymnoscopelus braueri, G. fraseri, G. nicholsi, Krefftichthys anderssoni, Protomyctophum bolini, P. tenisoni, P. choriodon and Nannobrachium achirus, in the Scotia Sea, together with their predatory impact on the underlying zooplankton community. Myctophids and their prey were sampled in different seasons by scientific nets deployed across the Scotia Sea from the sea-ice zone to the APF. Based on the percentage index of relative importance, myctophids had high overlap in their diets, although the data indicate dietary specialisation in some species. There was also a distinct switch in diet, from copepods to euphausiids and amphipods, with increasing myctophid size. Myctophid predation impacted daily copepod production by between 0.01 and 5%, with Calanus simillimus being most impacted. Total annual consumption of copepods was around 1.5 million t (Mt) per year. All myctophids preyed upon the euphausiid Thysanoessa spp., consuming ~12% of its daily productivity and around 4 Mt per year. However, only larger myctophid species preyed upon Antarctic krill Euphausia superba, consuming 2% of its daily productivity, which could amount to as much as 17 Mt per year. Themisto gaudichaudii was also an important dietary component, with 4% of its daily productivity being consumed, amounting to around 2 Mt per year. This study demonstrates that myctophids link secondary productivity to higher predators both through krill-dependent and krill-independent trophic pathways
Towards a formalism for mapping the spacetimes of massive compact objects: Bumpy black holes and their orbits
Observations have established that extremely compact, massive objects are
common in the universe. It is generally accepted that these objects are black
holes. As observations improve, it becomes possible to test this hypothesis in
ever greater detail. In particular, it is or will be possible to measure the
properties of orbits deep in the strong field of a black hole candidate (using
x-ray timing or with gravitational-waves) and to test whether they have the
characteristics of black hole orbits in general relativity. Such measurements
can be used to map the spacetime of a massive compact object, testing whether
the object's multipoles satisfy the strict constraints of the black hole
hypothesis. Such a test requires that we compare against objects with the
``wrong'' multipole structure. In this paper, we present tools for constructing
bumpy black holes: objects that are almost black holes, but that have some
multipoles with the wrong value. The spacetimes which we present are good deep
into the strong field of the object -- we do not use a large r expansion,
except to make contact with weak field intuition. Also, our spacetimes reduce
to the black hole spacetimes of general relativity when the ``bumpiness'' is
set to zero. We propose bumpy black holes as the foundation for a null
experiment: if black hole candidates are the black holes of general relativity,
their bumpiness should be zero. By comparing orbits in a bumpy spacetime with
those of an astrophysical source, observations should be able to test this
hypothesis, stringently testing whether they are the black holes of general
relativity. (Abridged)Comment: 16 pages + 2 appendices + 3 figures. Submitted to PR
Linearization of homogeneous, nearly-isotropic cosmological models
Homogeneous, nearly-isotropic Bianchi cosmological models are considered.
Their time evolution is expressed as a complete set of non-interacting linear
modes on top of a Friedmann-Robertson-Walker background model. This connects
the extensive literature on Bianchi models with the more commonly-adopted
perturbation approach to general relativistic cosmological evolution.
Expressions for the relevant metric perturbations in familiar coordinate
systems can be extracted straightforwardly. Amongst other possibilities, this
allows for future analysis of anisotropic matter sources in a more general
geometry than usually attempted.
We discuss the geometric mechanisms by which maximal symmetry is broken in
the context of these models, shedding light on the origin of different Bianchi
types. When all relevant length-scales are super-horizon, the simplest Bianchi
I models emerge (in which anisotropic quantities appear parallel transported).
Finally we highlight the existence of arbitrarily long near-isotropic epochs
in models of general Bianchi type (including those without an exact isotropic
limit).Comment: 31 pages, 2 figures. Submitted to CQ
Moving from information and collaboration to action: report from the 3rd International Dog Health Workshop, Paris in April 2017
Abstract Background Breed-related health problems in dogs have received increased focus over the last decade. Responsibility for causing and/or solving these problems has been variously directed towards dog breeders and kennel clubs, the veterinary profession, welfare scientists, owners, regulators, insurance companies and the media. In reality, all these stakeholders are likely to share some responsibility and optimal progress on resolving these challenges requires all key stakeholders to work together. The International Partnership for Dogs (IPFD), together with an alternating host organization, holds biennial meetings called the International Dog Health Workshops (IDHW). The Société Centrale Canine (French Kennel Club) hosted the 3rd IDHW, in Paris, in April, 2017. These meetings bring together a wide range of stakeholders in dog health, science and welfare to improve international sharing of information and resources, to provide a forum for ongoing collaboration, and to identify specific needs and actions to improve health, well-being and welfare in dogs. Results The workshop included 140 participants from 23 countries and was structured around six important issues facing those who work to improve dog health. These included individualized breed-specific strategies for health and breeding, extreme conformations, education and communication in relation to antimicrobial resistance, behavior and welfare, genetic testing and population-based evidence. A number of exciting actions were agreed during the meeting. These included setting up working groups to create tools to help breed clubs accelerate the implementation of breed-health strategies, review aspects of extreme conformation and share useful information on behavior. The meeting also heralded the development of an online resource of relevant information describing quality measures for DNA testing. A demand for more and better data and evidence was a recurring message stressed across all themes. Conclusions The meeting confirmed the benefits from inclusion of a diverse range of stakeholders who all play relevant and collaborative parts to improve future canine health. Firm actions were set for progress towards improving breed-related welfare. The next international workshop will be in the UK in 2019 and will be organized by the UK Kennel Club
KELT-6b: A P~7.9 d Hot Saturn Transiting a Metal-Poor Star with a Long-Period Companion
We report the discovery of KELT-6b, a mildly-inflated Saturn-mass planet
transiting a metal-poor host. The initial transit signal was identified in
KELT-North survey data, and the planetary nature of the occulter was
established using a combination of follow-up photometry, high-resolution
imaging, high-resolution spectroscopy, and precise radial velocity
measurements. The fiducial model from a global analysis including constraints
from isochrones indicates that the V=10.38 host star (BD+31 2447) is a mildly
evolved, late-F star with T_eff=6102 \pm 43 K, log(g_*)=4.07_{-0.07}^{+0.04}
and [Fe/H]=-0.28 \pm 0.04, with an inferred mass M_*=1.09 \pm 0.04 M_sun and
radius R_star=1.58_{-0.09}^{+0.16} R_sun. The planetary companion has mass
M_P=0.43 \pm 0.05 M_J, radius R_P=1.19_{-0.08}^{+0.13} R_J, surface gravity
log(g_P)=2.86_{-0.08}^{+0.06}, and density rho_P=0.31_{-0.08}^{+0.07}
g~cm^{-3}. The planet is on an orbit with semimajor axis a=0.079 \pm 0.001 AU
and eccentricity e=0.22_{-0.10}^{+0.12}, which is roughly consistent with
circular, and has ephemeris of T_c(BJD_TDB)=2456347.79679 \pm 0.00036 and
P=7.845631 \pm 0.000046 d. Equally plausible fits that employ empirical
constraints on the host star parameters rather than isochrones yield a larger
planet mass and radius by ~4-7%. KELT-6b has surface gravity and incident flux
similar to HD209458b, but orbits a host that is more metal poor than HD209458
by ~0.3 dex. Thus, the KELT-6 system offers an opportunity to perform a
comparative measurement of two similar planets in similar environments around
stars of very different metallicities. The precise radial velocity data also
reveal an acceleration indicative of a longer-period third body in the system,
although the companion is not detected in Keck adaptive optics images.Comment: Published in AJ, 17 pages, 15 figures, 6 table
Genetic Analysis of Hematological Parameters in Incipient Lines of the Collaborative Cross
Hematological parameters, including red and white blood cell counts and hemoglobin concentration, are widely used clinical indicators of health and disease. These traits are tightly regulated in healthy individuals and are under genetic control. Mutations in key genes that affect hematological parameters have important phenotypic consequences, including multiple variants that affect susceptibility to malarial disease. However, most variation in hematological traits is continuous and is presumably influenced by multiple loci and variants with small phenotypic effects. We used a newly developed mouse resource population, the Collaborative Cross (CC), to identify genetic determinants of hematological parameters. We surveyed the eight founder strains of the CC and performed a mapping study using 131 incipient lines of the CC. Genome scans identified quantitative trait loci for several hematological parameters, including mean red cell volume (Chr 7 and Chr 14), white blood cell count (Chr 18), percent neutrophils/lymphocytes (Chr 11), and monocyte number (Chr 1). We used evolutionary principles and unique bioinformatics resources to reduce the size of candidate intervals and to view functional variation in the context of phylogeny. Many quantitative trait loci regions could be narrowed sufficiently to identify a small number of promising candidate genes. This approach not only expands our knowledge about hematological traits but also demonstrates the unique ability of the CC to elucidate the genetic architecture of complex traits
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