2,380 research outputs found
Gerrymandering and Compactness: Implementation Flexibility and Abuse
The shape of an electoral district may suggest whether it was drawn with
political motivations, or gerrymandered. For this reason, quantifying the shape
of districts, in particular their compactness, is a key task in politics and
civil rights. A growing body of literature suggests and analyzes compactness
measures mathematically, but little consideration has been given to how these
scores should be calculated in practice. Here, we consider the effects of a
number of decisions that must be made in interpreting and implementing a set of
popular compactness scores. We show that the choices made in quantifying
compactness may themselves become political tools, with seemingly innocuous
decisions leading to disparate scores. We show that when the full range of
implementation flexibility is used, it can be abused to make clearly
gerrymandered districts appear quantitatively reasonable. This complicates
using compactness as a legislative or judicial standard to counteract unfair
redistricting practices. This paper accompanies the release of packages in C++,
Python, and R which correctly, efficiently, and reproducibly calculate a
variety of compactness scores.Comment: 10 pages, 17 figures, 1 tabl
Competing in the global economy: the competitiveness of the South African automotive components industry
Optimized up-down asymmetry to drive fast intrinsic rotation in tokamaks
Breaking the up-down symmetry of the tokamak poloidal cross-section can
significantly increase the spontaneous rotation due to turbulent momentum
transport. In this work, we optimize the shape of flux surfaces with both
tilted elongation and tilted triangularity in order to maximize this drive of
intrinsic rotation. Nonlinear gyrokinetic simulations demonstrate that adding
optimally-tilted triangularity can double the momentum transport of a tilted
elliptical shape. This work indicates that tilting the elongation and
triangularity in an ITER-like device can reduce the energy transport and drive
intrinsic rotation with an Alfv\'{e}n Mach number on the order of . This
rotation is four times larger than the rotation expected in ITER and is
sufficient to stabilize MHD instabilities. It is shown that this optimal shape
can be created using the shaping coils of several experiments.Comment: 16 pages, 5 figure
A Combined Limit on the Neutrino Mass from Neutrinoless Double-Beta Decay and Constraints on Sterile Majorana Neutrinos
We present a framework to combine data from the latest neutrinoless
double-beta decay experiments for multiple isotopes and derive a limit on the
effective neutrino mass using the experimental energy distributions. The
combined limits on the effective mass range between 130-310 meV, where the
spread is due to different model calculations of nuclear matrix elements
(NMEs). The statistical consistency (p values) between this result and the
signal observation claimed by the Heidelberg-Moscow experiment is derived. The
limits on the effective mass are also evaluated in a (3+1) sterile neutrino
model, assuming all neutrinos are Majorana particles.Comment: 8 pages, 8 figures. Version accepted by Phys Rev D, including latest
CUORE-0 result
Differences in the Presentation of Anorexia Nervosa between Males and Females
Anorexia nervosa (AN) is a serious psychiatric illness with an estimated lifetime prevalence of 0.3% in males and 0.9% in females. AN has the highest mortality rate of any psychiatric disorder—10-12 times greater than the general population, and approximately 20% of those with AN commit suicide. Unfortunately, most studies related to AN and other eating disorders (ED’s) have focused on females, leaving a relative scarcity of literature related to the presentation of AN among males. A complete understanding of AN’s signs and symptoms in both males and females is required for reliable detection in all individuals, as diagnostic bias favoring typical presentations of AN among females may contribute to under-detection, late detection, or improper treatment for males with AN. This review summarizes the state of the literature on differences in the presentation of AN between males and females in order to improve detection of AN in all individuals as well as guide future research investigating the efficacy and appropriateness of treatment methods in both females and males.Master of Public Healt
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