2,683 research outputs found
Methods of Repression in Bahrain during the 20th and 21st Century: From the Civil List to Social Media
Despite being afflicted by cyclical bouts of unrest over the past century, repression in Bahrain as a concept has not been the focus of considerable academic attention. This is the first interpretive historical and contemporary study of repression in Bahrain. It addresses the limitations of regime-type analysis and quantitative studies of repression, which tend to focus on the co-variation between repression and demobilization. Using a template analysis, a virtual ethnography and framing theory, this thesis offers a new conceptualisation of repression. Several episodes of contention in Bahrain are analysed, including; tribal resistance to the British reforms of the 1920s, the rise of the Higher Executive Committee in the 1950s, the leftist agitation of the 1970s, the 1990s Intifada, and the 2001 Uprising. Using evidence from multiple sources, including recently released Foreign and Commonwealth Office files, social media, and historical records, this thesis argues that Bahrain's protecting powers have had a marked impact on the severity, nature and type of repression in Bahrain, as well as the structure of the repressive apparatus. While the British mitigated the excesses of Al Khalifa's treatment of political opposition, their declining influence following Independence saw the rise of a Saudi-Al Khalifa dual authority structure that created a new approach to repressive choices. Crucially, Bahrain's protecting powers influenced the nature and type of repression that was applied to political opposition. Yet despite this meta-narrative of outside influence, this research complicates generalisable theories of repression, showing that repressive choices are often contingent on a complex mix of the availability of resources, elite attitudes, strategic objectives of power holders, and the nature of threat. For this reason, the research sheds light on repression in Bahrain, but also highlights the value of conducting case studies and long term studies that allow researchers to compare and contrast the reasons motivating repressive choices. The new conceptualisation also emphasises the rising importance of social media and rhizomatic actors as tools of repression
Covid-19 in Qatar: Well Versed in Crisis Management
As of April 13th 2020, Qatar has 2979 positive cases of Covid-19. Like a number of other countries, Qatar was caught off guard by the novel respiratory virus. Initially assessed as posing a low risk to the country, the first limited spate of cases offered a false sense of security. These were mostly Qatari nationals arriving back from Iran, where the outbreak had already escalated considerably. The first reported case was a Qatari national who had been in Iran. He was quarantined on approximately the 27th February
Reinforcement Learning Produces Dominant Strategies for the Iterated Prisoner's Dilemma
We present tournament results and several powerful strategies for the
Iterated Prisoner's Dilemma created using reinforcement learning techniques
(evolutionary and particle swarm algorithms). These strategies are trained to
perform well against a corpus of over 170 distinct opponents, including many
well-known and classic strategies. All the trained strategies win standard
tournaments against the total collection of other opponents. The trained
strategies and one particular human made designed strategy are the top
performers in noisy tournaments also
An open reproducible framework for the study of the iterated prisoner's dilemma
The Axelrod library is an open source Python package that allows for
reproducible game theoretic research into the Iterated Prisoner's Dilemma. This
area of research began in the 1980s but suffers from a lack of documentation
and test code. The goal of the library is to provide such a resource, with
facilities for the design of new strategies and interactions between them, as
well as conducting tournaments and ecological simulations for populations of
strategies.
With a growing collection of 139 strategies, the library is a also a platform
for an original tournament that, in itself, is of interest to the game
theoretic community. This paper describes the Iterated Prisoner's Dilemma, the
Axelrod library and its development, and insights gained from some novel
research.Comment: 11 pages, Journal of Open Research Software 4.1 (2016
Groups of Galaxies in AEGIS: The 200 ksec Chandra Extended X-ray Source catalogue
We present the discovery of seven X-ray emitting groups of galaxies selected
as extended X-ray sources in the 200 ksec Chandra coverage of the
All-wavelength Extended Groth Strip International Survey (AEGIS). In addition,
we report on AGN activity associated to these systems. Using the DEEP2 Galaxy
Redshift Survey coverage, we identify optical counterparts and determine
velocity dispersions. In particular, we find three massive high-redshift groups
at z>0.7, one of which is at z=1.13, the first X-ray detections of
spectroscopically selected DEEP2 groups. We also present a first look at the
the L_X-T, L_X-sigma, and sigma-T scaling relations for high-redshift massive
groups. We find that the properties of these X-ray selected systems agree well
with the scaling relations of similar systems at low redshift, although there
are X-ray undetected groups in the DEEP2 catalogue with similar velocity
dispersions. The other three X-ray groups with identified redshifts are
associated with lower mass groups at z~0.07 and together form part of a large
structure or "supergroup" in the southern portion of the AEGIS field. All of
the low-redshift systems are centred on massive elliptical galaxies, and all of
the high-redshift groups have likely central galaxies or galaxy pairs. All of
the central group galaxies host X-ray point sources, radio sources, and/or show
optical AGN emission. Particularly interesting examples of central AGN activity
include a bent-double radio source plus X-ray point source at the center of a
group at z=0.74, extended radio and double X-ray point sources associated to
the central galaxy in the lowest-redshift group at z=0.066, and a bright green
valley galaxy (part of a pair) in the z=1.13 group which shows optical AGN
emission lines.Comment: accepted to MNRAS, 15 pages, 11 figures, for version with full
resolution figures see http://www.ucolick.org/~tesla/aegis_groups.ps.g
US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report
This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in
Dark Matter" held at University of Maryland on March 23-25, 2017.Comment: 102 pages + reference
Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial
Background
Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
HNF4A and GATA6 loss reveals therapeutically actionable subtypes in pancreatic cancer
Pancreatic ductal adenocarcinoma (PDAC) can be divided into transcriptomic subtypes with two broad lineages referred to as classical (pancreatic) and squamous. We find that these two subtypes are driven by distinct metabolic phenotypes. Loss of genes that drive endodermal lineage specification, HNF4A and GATA6, switch metabolic profiles from classical (pancreatic) to predominantly squamous, with glycogen synthase kinase 3 beta (GSK3β) a key regulator of glycolysis. Pharmacological inhibition of GSK3β results in selective sensitivity in the squamous subtype; however, a subset of these squamous patient-derived cell lines (PDCLs) acquires rapid drug tolerance. Using chromatin accessibility maps, we demonstrate that the squamous subtype can be further classified using chromatin accessibility to predict responsiveness and tolerance to GSK3β inhibitors. Our findings demonstrate that distinct patterns of chromatin accessibility can be used to identify patient subgroups that are indistinguishable by gene expression profiles, highlighting the utility of chromatin-based biomarkers for patient selection in the treatment of PDAC
Searching for a Stochastic Background of Gravitational Waves with LIGO
The Laser Interferometer Gravitational-wave Observatory (LIGO) has performed
the fourth science run, S4, with significantly improved interferometer
sensitivities with respect to previous runs. Using data acquired during this
science run, we place a limit on the amplitude of a stochastic background of
gravitational waves. For a frequency independent spectrum, the new limit is
. This is currently the most sensitive
result in the frequency range 51-150 Hz, with a factor of 13 improvement over
the previous LIGO result. We discuss complementarity of the new result with
other constraints on a stochastic background of gravitational waves, and we
investigate implications of the new result for different models of this
background.Comment: 37 pages, 16 figure
LSST: from Science Drivers to Reference Design and Anticipated Data Products
(Abridged) We describe here the most ambitious survey currently planned in
the optical, the Large Synoptic Survey Telescope (LSST). A vast array of
science will be enabled by a single wide-deep-fast sky survey, and LSST will
have unique survey capability in the faint time domain. The LSST design is
driven by four main science themes: probing dark energy and dark matter, taking
an inventory of the Solar System, exploring the transient optical sky, and
mapping the Milky Way. LSST will be a wide-field ground-based system sited at
Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m
effective) primary mirror, a 9.6 deg field of view, and a 3.2 Gigapixel
camera. The standard observing sequence will consist of pairs of 15-second
exposures in a given field, with two such visits in each pointing in a given
night. With these repeats, the LSST system is capable of imaging about 10,000
square degrees of sky in a single filter in three nights. The typical 5
point-source depth in a single visit in will be (AB). The
project is in the construction phase and will begin regular survey operations
by 2022. The survey area will be contained within 30,000 deg with
, and will be imaged multiple times in six bands, ,
covering the wavelength range 320--1050 nm. About 90\% of the observing time
will be devoted to a deep-wide-fast survey mode which will uniformly observe a
18,000 deg region about 800 times (summed over all six bands) during the
anticipated 10 years of operations, and yield a coadded map to . The
remaining 10\% of the observing time will be allocated to projects such as a
Very Deep and Fast time domain survey. The goal is to make LSST data products,
including a relational database of about 32 trillion observations of 40 billion
objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures
available from https://www.lsst.org/overvie
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