14,957 research outputs found
Media Coverage of Law Enforcement Use of Force and Disability
Disability intersects with other factors such as race, class, gender, and sexuality, to magnify degrees of marginalization and increase the risk of violence. When the media ignores or mishandles a major factor, as we contend they generally do with disability, it becomes harder to effect change.This white paper focuses on the three years of media coverage of police violence and disability since the death of a young man with Down syndrome, named Ethan Saylor, in January 2013. After reviewing media coverage of eight selected cases of police violence against individuals with disabilities, the paper reveals the following patterns in the overall data:? Disability goes unmentioned or is listed as an attribute without context.? An impairment is used to evoke pity or sympathy for the victim.? A medical condition or "mental illness" is used to blame victims for their deaths.? In rare instances, we have identified thoughtful examinations of disability from within its social context that reveal the intersecting forces that lead to dangerous use-of-force incidents. Such stories point the way to better models for policing in the future. We conclude by proposing best practices for reporting on disability and police violence
Plasma membrane association by N-acylation governs PKG function in Toxoplasma gondii
ABSTRACT
Cyclic GMP (cGMP)-dependent protein kinase (protein kinase G [PKG]) is essential for microneme secretion, motility, invasion, and egress in apicomplexan parasites, However, the separate roles of two isoforms of the kinase that are expressed by some apicomplexans remain uncertain. Despite having identical regulatory and catalytic domains, PKG
I
is plasma membrane associated whereas PKG
II
is cytosolic in
Toxoplasma gondii
. To determine whether these isoforms are functionally distinct or redundant, we developed an auxin-inducible degron (AID) tagging system for conditional protein depletion in
T. gondii
. By combining AID regulation with genome editing strategies, we determined that PKG
I
is necessary and fully sufficient for PKG-dependent cellular processes. Conversely, PKG
II
is functionally insufficient and dispensable in the presence of PKG
I
. The difference in functionality mapped to the first 15 residues of PKG
I
, containing a myristoylated Gly residue at position 2 that is critical for membrane association and PKG function. Collectively, we have identified a novel requirement for cGMP signaling at the plasma membrane and developed a new system for examining essential proteins in
T. gondii
.
IMPORTANCE
Toxoplasma gondii
is an obligate intracellular apicomplexan parasite and important clinical and veterinary pathogen that causes toxoplasmosis. Since apicomplexans can only propagate within host cells, efficient invasion is critically important for their life cycles. Previous studies using chemical genetics demonstrated that cyclic GMP signaling through protein kinase G (PKG)-controlled invasion by apicomplexan parasites. However, these studies did not resolve functional differences between two compartmentalized isoforms of the kinase. Here we developed a conditional protein regulation tool to interrogate PKG isoforms in
T. gondii
. We found that the cytosolic PKG isoform was largely insufficient and dispensable. In contrast, the plasma membrane-associated isoform was necessary and fully sufficient for PKG function. Our studies identify the plasma membrane as a key location for PKG activity and provide a broadly applicable system for examining essential proteins in
T. gondii
.
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A Statistical Analysis of the Solar Phenomena Associated with Global EUV Waves
Solar eruptions are the most spectacular events in our solar system and are
associated with many different signatures of energy release including solar
flares, coronal mass ejections, global waves, radio emission and accelerated
particles. Here, we apply the Coronal Pulse Identification and Tracking
Algorithm (CorPITA) to the high cadence synoptic data provided by the Solar
Dynamic Observatory (SDO) to identify and track global waves observed by SDO.
164 of the 362 solar flare events studied (45%) are found to have associated
global waves with no waves found for the remaining 198 (55%). A clear linear
relationship was found between the median initial velocity and the acceleration
of the waves, with faster waves exhibiting a stronger deceleration (consistent
with previous results). No clear relationship was found between global waves
and type II radio bursts, electrons or protons detected in-situ near Earth.
While no relationship was found between the wave properties and the associated
flare size (with waves produced by flares from B to X-class), more than a
quarter of the active regions studied were found to produce more than one wave
event. These results suggest that the presence of a global wave in a solar
eruption is most likely determined by the structure and connectivity of the
erupting active region and the surrounding quiet solar corona rather than by
the amount of free energy available within the active region.Comment: 33 pages, 6 figures, 1 table. Accepted for publication in Solar
Physic
Kinematic Properties of Globally-Propagating Waves in the Solar Corona
Globally-propagating coronal bright fronts (CBFs) in the solar corona are
among the most dramatic manifestations of solar activity, but are not well
understood despite strong links with both solar flares and coronal mass
ejections. Extreme UltraViolet (EUV) observations from the STEREO and SDO
spacecraft are used here to study their kinematics and morphology. The first
STEREO observations of a CBF are presented, with the pulse observed in all
available EUV passbands (171, 195, 284 and for the first time, 304A). The pulse
displayed similar kinematics in all passbands, although the derived pulse
velocity and acceleration were found to be strongly influenced by the observing
cadence, implying that previous kinematics may have been underestimated.
Different techniques for identifying CBFs and deriving their true kinematics
were tested, with traditional techniques shown to be prone to undefined
user-dependent errors. This was overcome through the development of a
statistically rigorous, semi-automated identification algorithm, which was then
used to determine the kinematics of four CBF events observed by STEREO. All of
the events studied exhibited clear deceleration as well as increases in both
spatial and temporal pulse width, indicating that the CBFs are dispersive. A
CBF pulse observed by both STEREO and SDO was also studied using the algorithm,
with lower initial velocity and weaker deceleration noted in STEREO
observations compared to SDO, reaffirming the effects of image cadence on the
derived kinematics. The kinematics obtained using SDO were highly passband
dependent, suggesting a compressive nature. Significant pulse broadening was
also noted in observations from both spacecraft, allowing the dispersion rate
of the pulse to be determined. These results indicate that coronal bright
fronts are best interpreted as fast-mode magnetoacoustic waves propagating in
an inhomogeneous medium.Comment: Thesis, 216 pages, 78 figure
Comparing Experiments to the Fault-Tolerance Threshold
Achieving error rates that meet or exceed the fault-tolerance threshold is a
central goal for quantum computing experiments, and measuring these error rates
using randomized benchmarking is now routine. However, direct comparison
between measured error rates and thresholds is complicated by the fact that
benchmarking estimates average error rates while thresholds reflect worst-case
behavior when a gate is used as part of a large computation. These two measures
of error can differ by orders of magnitude in the regime of interest. Here we
facilitate comparison between the experimentally accessible average error rates
and the worst-case quantities that arise in current threshold theorems by
deriving relations between the two for a variety of physical noise sources. Our
results indicate that it is coherent errors that lead to an enormous mismatch
between average and worst case, and we quantify how well these errors must be
controlled to ensure fair comparison between average error probabilities and
fault-tolerance thresholds.Comment: 5 pages, 2 figures, 13 page appendi
Unitarisation of EFT Amplitudes for Dark Matter Searches at the LHC
We propose a new approach to the LHC dark matter search analysis within the
effective field theory (EFT) framework by utilising the K-matrix unitarisation
formalism. This approach provides a reasonable estimate of the dark matter
production cross section at high energies, and hence allows reliable bounds to
be placed on the cut-off scale of relevant operators without running into the
problem of perturbative unitarity violation. We exemplify this procedure for
the effective operator D5 in monojet dark matter searches in the collinear
approximation. We compare our bounds to those obtained using the truncation
method and identify a parameter region where the unitarisation prescription
leads to more stringent bounds.Comment: 20 pages, 7 figures. References added and minor corrections made to
match published versio
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