780 research outputs found
New Limits to the Infrared Background: Bounds on Radiative Neutrino Decay and on Contributions of Very Massive Objects to the Dark Matter Problem
From considering the effect of Îł-Îł interactions on recently observed TeV gamma-ray spectra, improved limits are set to the density of extragalactic infrared photons which are robust and essentially model independent. The resulting limits are more than an order of magnitude more restrictive than direct observations in the 0.025â0.3 eV regime. These limits are used to improve constraints on radiative neutrino decay in the mass range above 0.05 eV and to rule out very massive objects as providing the dark matter needed to explain galaxy rotation curves. Lower bounds on the maximum distance which TeV gamma rays may probe are also derived
Tidal Response of Mars Constrained From Laboratory-Based Viscoelastic Dissipation Models and Geophysical Data
We employ laboratory-based grain-size- and temperature-sensitive rheological models to
16 describe the viscoelastic behavior of terrestrial bodies with focus on Mars. Shear modulus
17 reduction and attenuation related to viscoelastic relaxation occur as a result of diffusion-
18 and dislocation-related creep and grain-boundary processes. We consider five rheological
19 models, including extended Burgers, Andrade, Sundberg-Cooper, a power-law approxima-
20 tion, and Maxwell, and determine Martian tidal response. However, the question of which
21 model provides the most appropriate description of dissipation in planetary bodies, re-
22 mains an open issue. To examine this, crust and mantle models (density and elasticity) are
23 computed self-consistently through phase equilibrium calculations as a function of pres-
24 sure, temperature, and bulk composition, whereas core properties are based on an Fe-FeS
25 parameterisation. We assess the compatibility of the viscoelastic models by inverting the
26 available geophysical data for Mars (tidal response and mean density and moment of in-
27 ertia) for temperature, elastic, and attenuation structure. Our results show that although
28 all viscoelastic models are consistent with data, their predictions for the tidal response at
29 other periods and harmonic degrees are distinct. The results also show that Maxwell is
30 only capable of fitting data for unrealistically low viscosities. Our approach can be used
31 quantitatively to distinguish between the viscoelastic models from seismic and/or tidal ob-
32 servations that will allow for improved constraints on interior structure (e.g., with InSight).
33 Finally, the methodology presented here is generally formulated and applicable to other so-
34 lar and extra-solar system bodies where the study of tidal dissipation presents an important
35 means for determining interior structure
Constructing seasonally adjusted data with time-varying confidence intervals
Seasonal adjustment methods transform observed time series data into estimated data, where these estimated data are constructed such that they show no or almost no seasonal variation. An advantage of model-based methods is that these can provide confidence intervals around the seasonally adjusted data. One particularly useful time series model for seasonal adjustment is the basic structural time series [BSM] model. The usual premise of the BSM is that the variance of each of the components is constant. In this paper we address the possibility that the variance of the trend component in a macro-economic time series in some way depends on the business cycle. One reason for doing so is that one can expect that there is more uncertainty in recession periods. We extend the BSM by allowing for a business-cycle dependent variance in the level equation. Next we show how this affects the confidence intervals of seasonally adjusted data. We apply our extended BSM to monthly US unemployment and we show that the estimated confidence intervals for seasonally adjusted unemployment change with past changes in the oil price
Searching for gravitational waves from known pulsars
We present upper limits on the amplitude of gravitational waves from 28
isolated pulsars using data from the second science run of LIGO. The results
are also expressed as a constraint on the pulsars' equatorial ellipticities. We
discuss a new way of presenting such ellipticity upper limits that takes
account of the uncertainties of the pulsar moment of inertia. We also extend
our previous method to search for known pulsars in binary systems, of which
there are about 80 in the sensitive frequency range of LIGO and GEO 600.Comment: Accepted by CQG for the proceeding of GWDAW9, 7 pages, 2 figure
Framework, principles and recommendations for utilising participatory methodologies in the co-creation and evaluation of public health interventions
Background:
Due to the chronic disease burden on society, there is a need for preventive public health interventions to stimulate society towards a healthier lifestyle. To deal with the complex variability between individual lifestyles and settings, collaborating with end-users to develop interventions tailored to their unique circumstances has been suggested as a potential way to improve effectiveness and adherence. Co-creation of public health interventions using participatory methodologies has shown promise but lacks a framework to make this process systematic. The aim of this paper was to identify and set key principles and recommendations for systematically applying participatory methodologies to co-create and evaluate public health interventions.
Methods:
These principles and recommendations were derived using an iterative reflection process, combining key learning from published literature in addition to critical reflection on three case studies conducted by research groups in three European institutions, all of whom have expertise in co-creating public health interventions using different participatory methodologies.
Results:
Key principles and recommendations for using participatory methodologies in public health intervention co-creation are presented for the stages of: Planning (framing the aim of the study and identifying the appropriate sampling strategy); Conducting (defining the procedure, in addition to manifesting ownership); Evaluating (the process and the effectiveness) and Reporting (providing guidelines to report the findings). Three scaling models are proposed to demonstrate how to scale locally developed interventions to a population level.
Conclusions:
These recommendations aim to facilitate public health intervention co-creation and evaluation utilising participatory methodologies by ensuring the process is systematic and reproducible
Search for Gravitational Waves from Primordial Black Hole Binary Coalescences in the Galactic Halo
We use data from the second science run of the LIGO gravitational-wave
detectors to search for the gravitational waves from primordial black hole
(PBH) binary coalescence with component masses in the range 0.2--.
The analysis requires a signal to be found in the data from both LIGO
observatories, according to a set of coincidence criteria. No inspiral signals
were found. Assuming a spherical halo with core radius 5 kpc extending to 50
kpc containing non-spinning black holes with masses in the range 0.2--, we place an observational upper limit on the rate of PBH coalescence
of 63 per year per Milky Way halo (MWH) with 90% confidence.Comment: 7 pages, 4 figures, to be submitted to Phys. Rev.
Crime, bandits, and community: how public panic shaped the social control of territory in the Ottoman Empire
This study explores the role of crime, bandits, and public panic in in the nineteenth century Ottoman society by using archival documents and employing a comparative perspective. In addition to the social bandit concept of Eric Hobsbawm, there is an introduction of two new banditry forms in this studyâopportunist bandits and imagined bandits. The comparison of different bandit forms clarifies that social bandits and opportunist bandits aggravated public panic and produced imagined bandits. Hence, public panic and the dissent of local people unveiled through rumors about the imagined bandits. The exploration of different forms of bandits in the Ottoman Empire is a response to the vexed issue concerning the challenges in the social control of territories in a multiethnic and multi-religious empire. This study provides new conceptual tools to rethink about the spatial dimensions in the emergence of bandits. This article shows that spatial factors in the social control of territory can be influenced by the reaction of local people from bottom-to-top and, in doing so, can determine the response of state authority. The present study, therefore, unveils the power relationship in the social control of territory whether it is manifested by physical force or public panic.N/
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