612 research outputs found
Response, Models, Race, and the Law
Capitalizing on recent advances in algorithmic sampling, The Race-Blind Future of Voting Rights explores the implications of the long-standing conservative dream of certified race neutrality in redistricting. Computers seem promising because they are excellent at not taking race into accountâbut computers only do what you tell them to do, and the rest of the authorsâ apparatus for measuring minority electoral opportunity failed every check of robustness and numerical stability that we applied. How many opportunity districts are there in the current Texas state House plan? Their methods can give any answer from thirty-four to fifty-one, depending on invisible settings. But if we focus only on major technical flaws, we might miss the fundamental fact that race-blind districting would devastate minority political opportunity no matter how it is deployed, just due to the mathematics of single-member districts. In the end, the Article develops an extreme interpretation of a dubious idea proposed by Judge Easterbrook through an empirical study that is unsupported by the methods
Response, Models, Race, and the Law
Capitalizing on recent advances in algorithmic sampling, The Race-Blind Future of Voting Rights explores the implications of the long-standing conservative dream of certified race neutrality in redistricting. Computers seem promising because they are excellent at not taking race into accountâbut computers only do what you tell them to do, and the rest of the authorsâ apparatus for measuring minority electoral opportunity failed every check of robustness and numerical stability that we applied. How many opportunity districts are there in the current Texas state House plan? Their methods can give any answer from thirty-four to fifty-one, depending on invisible settings. But if we focus only on major technical flaws, we might miss the fundamental fact that race-blind districting would devastate minority political opportunity no matter how it is deployed, just due to the mathematics of single-member districts. In the end, the Article develops an extreme interpretation of a dubious idea proposed by Judge Easterbrook through an empirical study that is unsupported by the methods
Blind Justice: Algorithms and Neutrality in the Case of Redistricting
In several areas of law and public policy, there have been longstanding dreams that computers can secure decision making that takes only some things into account, while remaining demonstrably neutral to other factors. In 2022, the U.S. Supreme Court will consider mandating race-neutrality in multiple domains, notably in college admissions and redistricting. In this piece, we clarify the real and imagined uses of computers in redistricting, considering their application for optimization approaches and, more recently, for representative sampling. The current pitch to the Court for a race-blind Voting Rights Act is discussed at length
Length functions on currents and applications to dynamics and counting
The aim of this (mostly expository) article is twofold. We first explore a
variety of length functions on the space of currents, and we survey recent work
regarding applications of length functions to counting problems. Secondly, we
use length functions to provide a proof of a folklore theorem which states that
pseudo-Anosov homeomorphisms of closed hyperbolic surfaces act on the space of
projective geodesic currents with uniform north-south dynamics.Comment: 35pp, 2 figures, comments welcome! Second version: minor corrections.
To appear as a chapter in the forthcoming book "In the tradition of Thurston"
edited by V. Alberge, K. Ohshika and A. Papadopoulo
The Leverage of Demographic Dynamics on Carbon Dioxide Emissions: Does Age Structure Matter?
This article provides a methodological contribution to the study of the effect of changes in population age structure on carbon dioxide (CO2) emissions. First, I propose a generalization of the IPAT equation to a multisector economy with an age-structured population and discuss the insights that can be obtained in the context of stable population theory. Second, I suggest a statistical model of household consumption as a function of household size and age structure to quantitatively evaluate the extent of economies of scale in consumption of energy-intensive goods, and to estimate age-specific profiles of consumption of energy-intensive goods and of CO2 emissions. Third, I offer an illustration of the methodologies using data for the United States. The analysis shows that per-capita CO2 emissions increase with age until the individual is in his or her 60s, and then emissions tend to decrease. Holding everything else constant, the expected change in U.S. population age distribution during the next four decades is likely to have a small, but noticeable, positive impact on CO2 emissions
What impact do posters have on academic knowledge transfer? A pilot survey on author attitudes and experiences
<p>Abstract</p> <p>Background</p> <p>Research knowledge is commonly facilitated at conferences via oral presentations, poster presentations and workshops. Current literature exploring the efficacy of academic posters is however limited. The purpose of this initial study was to explore the perceptions of academic poster presentation, together with its benefits and limitations as an effective mechanism for academic knowledge transfer and contribute to the available academic data.</p> <p>Methods</p> <p>A survey was distributed to 88 delegates who presented academic posters at two Releasing Research and Enterprise Potential conferences in June 2007 and June 2008 at Bournemouth University. This survey addressed attitude and opinion items, together with their general experiences of poster presentations. Descriptive statistics were performed on the responses.</p> <p>Results</p> <p>A 39% return was achieved with the majority of respondents believing that posters are a good medium for transferring knowledge and a valid form of academic publication. Visual appeal was cited as more influential than subject content, with 94% agreeing that poster imagery is most likely to draw viewer's attention. Respondents also believed that posters must be accompanied by their author in order to effectively communicate the academic content.</p> <p>Conclusion</p> <p>This pilot study is the first to explore perceptions of the academic poster as a medium for knowledge transfer. Given that academic posters rely heavily on visual appeal and direct author interaction, the medium requires greater flexibility in their design to promote effective knowledge transfer. This paper introduces the concept of the IT-based 'MediaPoster' so as to address the issues raised within published literature and subsequently enhance knowledge-transfer within the field of academic medicine.</p
Clusters of Hantavirus Infection, Southern Argentina
Person-to-person transmission should be suspected when Andes virus case-patients are linked
Utjecaj razliÄitih povrĹĄinski aktivnih tvari i njihovih koncentracija na kontrolirano oslobaÄanje kaptoprila iz polimernih matriksa
Various methods are available to formulate water soluble drugs into sustained release dosage forms by retarding the dissolution rate. One of the methods used to control drug release and thereby prolong therapeutic activity is to use hydrophilic and lipophilic polymers. In this study, the effects of various polymers such as hydroxypropyl methylcellulose (HPMC), ethylcellulose (EC) and sodium carboxymethylcellulose (CMC) and surfactants (sodium lauryl sulphate, cetyltrimethylammonium bromide and Arlacel 60) on the release rate of captopril were investigated. The results showed that an increase in the amount of HPMC K15M resulted in reduction of the release rate of captopril from these matrices. When HPMC was partly replaced by NaCMC (the ratio of HPMC/NaCMC was 5:1), the release rate of the drug significantly decreased. However, there was no significant difference in release rate of captopril from matrices produced with ratios of 5:1 and 2:1 of HPMC/NaCMC. The presence of lactose in matrices containing HPMC and NaCMC increased the release rate of captopril. It was interesting to note that although partial replacement of HPMC by EC reduced the release rate of the drug (ratio of HPMC/EC 2:1), the release rate was increased when the ratio of HPMC/EC was reduced to 1:1. The effects of various surfactants on the release rate of captopril from HPMC/EC 1:1 matrices were also investigated. The results showed that the surfactants did not significantly change the release rate of the drug. Release data were examined kinetically and the ideal kinetic models were estimated for the drug release. The kinetic analysis of drug release data from various formulations showed that incorporation of surfactants in HPMC/EC matrices did not produce a zero-order release pattern.Postoje razliÄite metode formuliranja vodotopljivih lijekova u dozirane ljekovite oblike s polaganim oslobaÄanjem. Jedan od naÄina postizanja kontroliranog otpuĹĄtanja, a prema tome i produljenog uÄinka je upotreba hidrofilnih i lipofilnih polimera. U ovom radu prouÄavan je utjecaj razliÄitih polimera poput hidroksipropil metilceluloze (HPMC), etilceluloze (EC) i natrijeve soli karboksimetilceluloze (NaCMC) i povrĹĄinski aktivnih tvari (natrijevog lauril-sulfata, cetiltrimetilamonijevog bromida i Arlacela 60) na oslobaÄanje kaptoprila. Rezultati pokazuju da poveÄanje koliÄine HPMC K15M ima za posljedicu smanjenje oslobaÄanja kaptoprila iz matriksa. Ako se HPMC djelomiÄno zamijeni s NaCMC (omjer HPMC/NaCMC 5:1), oslobaÄanje ljekovite tvari znaÄajno se smanjuje. MeÄutim, nema znaÄajne razlike u oslobaÄanju kaptoprila iz matriksa s omjerom HPMC/NaCMC 5:1 i 2:1. Prisutnost laktoze u matriksu koji sadrĹži HPMC i NaCMC poveÄalo je oslobaÄanje kaptoprila. Iako djelomiÄna zamjena HPMC s EC smanjuje oslobaÄanje ljekovite tvari (omjer HPMC/EC 2:1), oslobaÄanje se poveÄava uz omjer HPMC/EC 1:1. Nadalje, ispitivan je utjecaj povrĹĄinski aktivnih tvari na oslobaÄanje kaptoprila iz matriksa u kojima je omjer HPMC/EC (1:1). MoĹže se zakljuÄiti da povrĹĄinski aktivne tvari ne utjeÄu znaÄajno na oslobaÄanje ljekovite tvari. U sklopu istraĹživanja odreÄen je i kinetiÄki model oslobaÄanja kaptoprila. Analiza kinetiÄkih podataka ukazuje da dodatak povrĹĄinski aktivnih tvari u HPMC/EC matrikse ne slijedi kinetiku nultog reda
A simulation study comparing aberration detection algorithms for syndromic surveillance
BACKGROUND: The usefulness of syndromic surveillance for early outbreak detection depends in part on effective statistical aberration detection. However, few published studies have compared different detection algorithms on identical data. In the largest simulation study conducted to date, we compared the performance of six aberration detection algorithms on simulated outbreaks superimposed on authentic syndromic surveillance data. METHODS: We compared three control-chart-based statistics, two exponential weighted moving averages, and a generalized linear model. We simulated 310 unique outbreak signals, and added these to actual daily counts of four syndromes monitored by Public Health â Seattle and King County's syndromic surveillance system. We compared the sensitivity of the six algorithms at detecting these simulated outbreaks at a fixed alert rate of 0.01. RESULTS: Stratified by baseline or by outbreak distribution, duration, or size, the generalized linear model was more sensitive than the other algorithms and detected 54% (95% CI = 52%â56%) of the simulated epidemics when run at an alert rate of 0.01. However, all of the algorithms had poor sensitivity, particularly for outbreaks that did not begin with a surge of cases. CONCLUSION: When tested on county-level data aggregated across age groups, these algorithms often did not perform well in detecting signals other than large, rapid increases in case counts relative to baseline levels
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