719 research outputs found
Urban Ecology and the Effectiveness of Aedes Control
Past initiatives to control Aedes mosquitoes were successful, in part because they implemented draconian top-down control programs. To achieve similar results now, explicit recognition of the complexity in urban ecologies in terms of land ownership, law enforcement and accessibility for control interventions are required. By combining these attributes, four classes of spaces, along with corresponding control strategies, are suggested to better target Aedes species population control efforts. On one end of the spectrum there are accessible and accountable spaces (e.g. backyards and closely managed public facilities), where interventions can rely predominantly on bottom-up strategies with the local population playing the principle role in the implementation of actions, but with government coordination. On the other end of the spectrum are inaccessible and unaccountable spaces, which require top-down and extensive approaches. By identifying these and the intermediate classes of space, government and private resources can be allocated in a more efficient customized manner. Based on this new framework, a set of actions is proposed that might be implemented in dengue and other Aedes-borne crises. The framework considers existing limitations and opportunities associated with modern societiesâwhich are fundamentally different from those associated with the successful control of Aedes species in the past
Understanding Violent-Crime Recidivism
People convicted of violent crimes constitute a majority of the imprisoned population but are generally ignored by existing policies aimed at reducing mass incarceration. Serious efforts to shrink the large footprint of the prison system will need to recognize this fact. This point is especially pressing at the time of this writing, as states and the federal system consider large-scale prison releases motivated by the COVID-19 pandemic. Those convicted of violent crimes constitute a large majority of older prisoners, who are extremely vulnerable to the spread of the virus behind bars. Excluding them from protective measures will deeply undermine those measuresâ effectivenessâand yet many governors and officials have hesitated due to fears of violent-crime recidivism. In addition, the population imprisoned for violent offenses also exhibits sharper demographic disparities than the general prison population across both age and race. Consequently, reforms that target those convicted only of nonviolent crimes will likely exacerbate existing inequalities in the criminal justice system. In this Article, we start from the premise that better understanding individuals convicted of violent crimes is essential to overcoming resistance to the idea of releasing them earlierâand in particular, to address the fear that this population will almost certainly reoffend violently. We review existing studies and offer new empirical analysis to inform these questions. Although estimates vary, our synthesis of the available evidence suggests that released violent offenders, especially homicide offenders who are older at release, have lower overall recidivism rates relative to other released offenders. At the same time, people released after previous homicide convictions may be more likely to commit new homicides than otherwise comparable releasees, although probably not by as much as most would expect
Understanding Violent-Crime Recidivism
People convicted of violent crimes constitute a majority of the imprisoned population but are generally ignored by existing policies aimed at reducing mass incarceration. Serious efforts to shrink the large footprint of the prison system will need to recognize this fact. This point is especially pressing at the time of this writing, as states and the federal system consider large-scale prison releases motivated by the COVID-19 pandemic. Those convicted of violent crimes constitute a large majority of older prisoners, who are extremely vulnerable to the spread of the virus behind bars. Excluding them from protective measures will deeply undermine those measuresâ effectivenessâand yet many governors and officials have hesitated due to fears of violent-crime recidivism. In addition, the population imprisoned for violent offenses also exhibits sharper demographic disparities than the general prison population across both age and race. Consequently, reforms that target those convicted only of nonviolent crimes will likely exacerbate existing inequalities in the criminal justice system. In this Article, we start from the premise that better understanding individuals convicted of violent crimes is essential to overcoming resistance to the idea of releasing them earlierâand in particular, to address the fear that this population will almost certainly reoffend violently. We review existing studies and offer new empirical analysis to inform these questions. Although estimates vary, our synthesis of the available evidence suggests that released violent offenders, especially homicide offenders who are older at release, have lower overall recidivism rates relative to other released offenders. At the same time, people released after previous homicide convictions may be more likely to commit new homicides than otherwise comparable releasees, although probably not by as much as most would expect
Bubbles from Nothing
Within the framework of flux compactifications, we construct an instanton
describing the quantum creation of an open universe from nothing. The solution
has many features in common with the smooth 6d bubble of nothing solutions
discussed recently, where the spacetime is described by a 4d compactification
of a 6d Einstein-Maxwell theory on S^2 stabilized by flux. The four-dimensional
description of this instanton reduces to that of Hawking and Turok. The choice
of parameters uniquely determines all future evolution, which we additionally
find to be stable against bubble of nothing instabilities.Comment: 19 pages, 6 figure
Decay of flux vacua to nothing
We construct instanton solutions describing the decay of flux
compactifications of a gauge theory by generalizing the Kaluza-Klein
bubble of nothing. The surface of the bubble is described by a smooth
magnetically charged solitonic brane whose asymptotic flux is precisely that
responsible for stabilizing the 4d compactification. We describe several
instances of bubble geometries for the various vacua occurring in a
Einstein-Maxwell theory namely, AdS_4 x S^2, R^{1,3} x S^2, and dS_4 x S^2.
Unlike conventional solutions, the bubbles of nothing introduced here occur
where a {\em two}-sphere compactification manifold homogeneously degenerates.Comment: 31 pages, 15 figure
Methods to assess the price of diets : a rapid literature review
This work was funded by the Scottish Governmentâs Rural and Environment Science and Analytical Services Division as part of the Strategic Research Programme 2022-2027 (project RI-B5-9 and Underpinning National Capacity Support for Policy).Publisher PD
Keep it simple: ranking health states yields values similar to cardinal measurement approaches
Abstract
OBJECTIVES: To examine the relationship between ordinal and cardinal valuation of health states.
STUDY DESIGN AND SETTING: We analyzed rank, visual analog scale (VAS), and time trade-off (TTO) responses for 52 health states defined using the EQ-5D classification system developed by the EuroQol Group. We analyzed 179,431 responses from 11,483 subjects in eight countries: Slovenia, Argentina, Denmark, Japan, Netherlands, Spain, United Kingdom, and United States. We first compared responses across methods by frequency of ties and values below dead. Ordinal associations between methods were evaluated using Spearman's correlation and Kendall's tau. Next, we estimated numerical values from rank responses using country-specific conditional logit models. After anchoring predicted values on a common scale, we further investigated the cardinal relationships between rank, VAS, and TTO-based values using Pearson's rho and quadratic regression.
RESULTS: For each country, rank responses are less likely than TTO responses to be tied and to indicate that states are worse than dead. In all countries, rank responses show a strong linear correlation with both TTO (Pearson's rho=0.88-0.99) and VAS (rho=0.91-0.98) responses. However, rank-ba
Incremental stability of hybrid dynamical systems
International audienceThe analysis of incremental stability typically involves measuring the distance between any two solutions of a given dynamical system at the same time instant, which is problematic when studying hybrid dynamical systems. Indeed, hybrid systems generate solutions defined with respect to hybrid time instances (that consists of both the continuous time elapsed and the discrete time, which is the number of jumps experienced so far), and two solutions of the same hybrid system may not be defined at the same hybrid time instant. To overcome this issue, we present novel definitions of incremental stability for hybrid systems based on graphical closeness of solutions. As we will show, defining incremental asymptotic stability with respect to the hybrid time yields a restrictive notion, such that we also investigate incremental asymptotic stability notions with respect to the continuous time only or the discrete time only, respectively. In this manner, two (effectively dual) incremental stability notions are attained, called jump-and flow incremental asymptotic stability. To present Lyapunov conditions for these two notions, in both cases, we resort to an extended hybrid system and we prove that the stability of a well-defined set for this extended system implies incremental stability of the original system. We can then use available Lyapunov conditions to infer the set stability of the extended system. Various examples are provided throughout the paper, including an event-triggered control application and a bouncing ball system with Zeno behaviour, that illustrate incremental stability with respect to continuous time or discrete time, respectively
SMART Vaccines 2.0 decision-support platform : A tool to facilitate and promote priority setting for sustainable vaccination in resource-limited settings
Funding Information: Supported by Gavi and the Bill and Melinda Gates Foundation, a number of international organisations have offered capacity-building support to establish NITAGs. While greater emphasis was initially placed on fulfilling process indicators for establishing NITAGs, more recent efforts have sought to advance functional capabilities associated with EIDM, most notably by Agence de MĂ©decine PrĂ©ventive (AMP), the International Vaccine Institute and The Sabin Vaccine Institute.13 14 These programmes have additionally leveraged technical assistance from WHO and its regional offices, PATH and the US Centers for Disease Control and Prevention.15 16 Funding Information: The UNITAG sought technical assistance from AMPâs Supporting Independent Vaccine Advisory Committees (SIVAC) Initiative,14and engaged in piloting the SMART Vaccines 2.0 platform supported by the Fogarty International Center at the US National Institutes of Health (NIH). A description of the NITAG process is given elsewhere.24 33 Funding Information: Funding This work was supported by the Fogarty International Center, National Institutes of Health, USA. Publisher Copyright: © 2020 Author(s). Published by BMJ.Peer reviewedPublisher PD
F-theory uplifts and GUTs
We study the F-theory uplift of Type IIB orientifold models on compact
Calabi-Yau threefolds containing divisors which are del Pezzo surfaces. We
consider two examples defined via del Pezzo transitions of the quintic. The
first model has an orientifold projection leading to two disjoint O7-planes and
the second involution acts via an exchange of two del Pezzo surfaces. The two
uplifted fourfolds are generically singular with minimal gauge enhancements
over a divisor and, respectively, a curve in the non-Fano base. We study
possible further degenerations of the elliptic fiber leading to F-theory GUT
models based on subgroups of E8.Comment: 28 pages, 5 tables; v2: typos removed, minor correction
- âŠ