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Origin of two-band chorus in the radiation belt of Earth.
Naturally occurring chorus emissions are a class of electromagnetic waves found in the space environments of the Earth and other magnetized planets. They play an essential role in accelerating high-energy electrons forming the hazardous radiation belt environment. Chorus typically occurs in two distinct frequency bands separated by a gap. The origin of this two-band structure remains a 50-year old question. Here we report, using NASA's Van Allen Probe measurements, that banded chorus waves are commonly accompanied by two separate anisotropic electron components. Using numerical simulations, we show that the initially excited single-band chorus waves alter the electron distribution immediately via Landau resonance, and suppress the electron anisotropy at medium energies. This naturally divides the electron anisotropy into a low and a high energy components which excite the upper-band and lower-band chorus waves, respectively. This mechanism may also apply to the generation of chorus waves in other magnetized planetary magnetospheres
Banks' risk assessment of Swedish SMEs
Building on the literatures on asymmetric information and risk taking, this paper applies conjoint experiments to investigate lending officers' probabilities of supporting credit to established or existing SMEs. Using a sample of 114 Swedish lending officers, we test hypotheses concerning how information on the borrower's ability to repay the loan; alignment of risk preferences; and risk sharing affect their willingness to grant credit. Results suggest that features that reduce the risk to the bank and shift the risk to the borrower have the largest impact. The paper highlights the interaction between factors that influence the credit decision. Implications for SMEs, banks and research are discussed
Gravitational effects on the high energy emission of accreting black holes
We extend the investigation of general relativistic effects on the observed
X-ray continuum of Kerr black holes in the context of the light bending model
(Miniutti & Fabian, 2004). Assuming a ring-like illuminating source,
co-rotating with the underlying accretion disk, we study the shape and
normalisation of the primary and disc reflected continuum as well as the
dependence of the observed spectrum on the line of sight for various source
heights and radii. These calculations are performed using Monte-Carlo methods
to compute the angle dependent reflection spectrum from the disc. The effects
of general relativity are illustrated by a comparison with Newtonian and
Special Relativity calculations. We find that relativistic distortions can
strongly affect the shape of the reflected spectrum. Light bending can
dramatically increase the observable reflected flux and reduce the primary
emission. In addition, multiple reflections due to the reflected photons
deflected toward the disc can alter significantly the shape of the spectrum
above 10 keV. Large variations of the ring radius at constant height can lead
to an (unobserved) anti-correlation between primary and reflected flux. In
another side, the variability behaviour of several sources can be reproduced if
the ring source radius is small (<5 r_g), and its height varies by a large
factor. In particular, a non-linear flux-flux relation, similar to that
observed in several sources, can be produced. We compare our model with the
flux-flux plot of NGC4051, and find an agreement for low inclination angles
(<20 deg.), ring source radius <3 r_g and a height varying between 0.5 to 10
r_g.Comment: 13 pages, 18 figures. Accepted for publication in A&
Factors related to high and low levels of drug adherence according to patients with type 2 diabetes
Objective Adherence to medication in patients with type 2 diabetes varies widely, yet the factors that influence adherence according to patients are not fully known. The aim of this study is to explore both factors related to high and lower levels of adherence that patients with type 2 diabetes experienced in their medication use. Setting Primary care in the Netherlands. Method Qualitative, semi-structured interviews were performed in 20 patients with type 2 diabetes. Interviews were audio-taped and transcribed verbatim. Transcripts were coded and analysed using content analysis and constant comparison. Main outcome measure experiences and opinions of patients concerning factors related to high and lower levels of adherence. Results Comparable aspects influenced drug adherence in more and less adherent patients. Four aspects that influenced adherence to medication emerged from the interviews: (1) information about the prescribed medication, (2) experience with medication and complications with use, (3) social support for medication behaviour and (4) routines in medication behaviour. Experience with medication and social support for medication behaviour were related to high levels of adherence in some patients, and to lower levels of adherence in others. Complicated medication regimens were mainly related to lower adherence, while social support and routines in medication behaviour were related to higher adherence. Conclusions Routines in medication behaviour were related to higher drug adherence. Patient education should not only address information about the disease and medication, but also more practical issues concerning drug intake. Hence, to improve drug adherence in patients with type 2 diabetes, pharmaceutical care might be aimed at the counselling of patients to organise drug use in their daily schedule
First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data
Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of
continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a
fully coherent search, based on matched filtering, which uses the position and rotational parameters
obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto-
noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch
between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have
been developed, allowing a fully coherent search for gravitational waves from known pulsars over a
fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of
11 pulsars using data from Advanced LIGOâs first observing run. Although we have found several initial
outliers, further studies show no significant evidence for the presence of a gravitational wave signal.
Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of
the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for
the first time. For an additional 3 targets, the median upper limit across the search bands is below the
spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried
out so far
Supermassive Black Holes in Galactic Nuclei: Past, Present and Future Research
This review discusses the current status of supermassive black hole research,
as seen from a purely observational standpoint. Since the early '90s, rapid
technological advances, most notably the launch of the Hubble Space Telescope,
the commissioning of the VLBA and improvements in near-infrared speckle imaging
techniques, have not only given us incontrovertible proof of the existence of
supermassive black holes, but have unveiled fundamental connections between the
mass of the central singularity and the global properties of the host galaxy.
It is thanks to these observations that we are now, for the first time, in a
position to understand the origin, evolution and cosmic relevance of these
fascinating objects.Comment: Invited Review, 114 pages. Because of space requirements, this
version contains low resolution figures. The full resolution version can be
downloaded from http://www.physics.rutgers.edu/~lff/publications.htm
A useful savagery: The invention of violence in nineteenth-century England
âA Useful Savagery: The Invention of Violence in Nineteenth-Century Englandâ considers a particular configuration of attitudes toward violence that emerged in the early decades of the nineteenth century. As part of a longer-term process of emerging âsensibilities,â violence was, seemingly paradoxically, âinventedâ as a social issue while concurrently relocated in the âcivilisedâ imagination as an anti-social feature mainly of âsavageâ working-class life. The dominant way this discourse evolved was through the creation of a narrative that defined âcivilisationâ in opposition to the presumed âsavageryâ of the working classes. Although the refined classes were often distanced from the physical experience of violence, concern with violence and brutality became significant parts of social commentary aimed at a middle-class readership. While stridently redefining themselves in opposition to âbrutality,â one of the purposes of this literature was to create a new middle class and justify the expansion of state power. By the closing decades of the nineteenth century, as the working classes adopted tenets of Victorian respectability, a proliferating number of social and psychological âothersâ were identified against which âcivilisedâ thought could define itself
Theorising age and generation in development: A relational approach
This introduction outlines the analytical approach informing the articles presented in this special issue. The project of âgenerationingâ development involves re-thinking development as distinctly generational in its dynamics. For this, we adopt a relational approach to the study of young people in development, which overcomes the limitations inherent to common categorising approaches. Concepts of age and generation are employed to conceptualise young people as social actors and life phases such as childhood and youth in relational terms. Acknowledging the centrality of young people in social reproduction puts them at the heart of development studies and leads the articles comprising this special issue to explore how young peopleâs agency shapes and is shaped by the changing terms of social reproduction brought about by development
Optimal CMB Lensing Reconstruction and Parameter Estimation with SPTpol Data
We perform the first simultaneous Bayesian parameter inference and optimal
reconstruction of the gravitational lensing of the cosmic microwave background
(CMB), using 100 deg of polarization observations from the SPTpol receiver
on the South Pole Telescope. These data reach noise levels as low as 5.8
K-arcmin in polarization, which are low enough that the typically used
quadratic estimator (QE) technique for analyzing CMB lensing is significantly
sub-optimal. Conversely, the Bayesian procedure extracts all lensing
information from the data and is optimal at any noise level. We infer the
amplitude of the gravitational lensing potential to be
using the Bayesian pipeline, consistent with
our QE pipeline result, but with 17\% smaller error bars. The Bayesian analysis
also provides a simple way to account for systematic uncertainties, performing
a similar job as frequentist "bias hardening," and reducing the systematic
uncertainty on due to polarization calibration from almost half of the
statistical error to effectively zero. Finally, we jointly constrain
along with , the amplitude of lensing-like effects on the CMB power
spectra, demonstrating that the Bayesian method can be used to easily infer
parameters both from an optimal lensing reconstruction and from the delensed
CMB, while exactly accounting for the correlation between the two. These
results demonstrate the feasibility of the Bayesian approach on real data, and
pave the way for future analysis of deep CMB polarization measurements with
SPT-3G, Simons Observatory, and CMB-S4, where improvements relative to the QE
can reach 1.5 times tighter constraints on and 7 times lower effective
lensing reconstruction noise.Comment: 27 pages, 14 figures, accompanying software package available at
https://cosmicmar.com/CMBLensing.j
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