How Much Risk is Acceptable?

The financial crisis has sparked proposals to reform the retirement income system. One component of such a system could be a new tier of retirement accounts. These accounts would augment declining Social Security replacement rates for low-wage workers and provide a buffer of security for middle- and upper-wage workers who, increasingly, will rely totally on 401(k) plans to supplement their Social Security. Designing such a new tier requires answering a number of questions: Mandatory or voluntary? Employee and/or employer contributions? Subsidies for low earners? Payments as lump sums or annuities? Tax favored or not? But the most fundamental question is whether the goal of the new tier is to provide a defined contribution account, where the retirement income will depend on market performance, or an account that can provide a certain percent of final earnings ñ that is, a target replacement rate...

ActiveRemediation: The Search for Lead Pipes in Flint, Michigan

We detail our ongoing work in Flint, Michigan to detect pipes made of lead and other hazardous metals. After elevated levels of lead were detected in residents' drinking water, followed by an increase in blood lead levels in area children, the state and federal governments directed over $125 million to replace water service lines, the pipes connecting each home to the water system. In the absence of accurate records, and with the high cost of determining buried pipe materials, we put forth a number of predictive and procedural tools to aid in the search and removal of lead infrastructure. Alongside these statistical and machine learning approaches, we describe our interactions with government officials in recommending homes for both inspection and replacement, with a focus on the statistical model that adapts to incoming information. Finally, in light of discussions about increased spending on infrastructure development by the federal government, we explore how our approach generalizes beyond Flint to other municipalities nationwide.Comment: 10 pages, 10 figures, To appear in KDD 2018, For associated promotional video, see https://www.youtube.com/watch?v=YbIn_axYu9

What Does It Cost To Guarantee Returns?

The financial crisis has dramatically demonstrated how a collapse in equity prices can decimate retirement accounts. The crisis highlights the fragility of existing 401(k) plans as the only supplement to Social Security and has sparked proposals to reform the retirement income system. One component of such a system could be a new tier of retirement accounts. Given the declines in the share of earnings Social Security will replace, these accounts would bolster replacement rates for low-wage workers and increase the security of middle- and upper-wage workers who increasingly rely on their 401(k) plans to supplement Social Security. However, these new accounts could face the same risk of collapse in value seen over the past year in 401(k)s. So policymakers may find some form of guaranteed return or risk sharing desirable to prevent huge variations in outcomes. This brief explores the feasible range and the cost of the first option – guarantees...

A Data Science Approach to Understanding Residential Water Contamination in Flint

When the residents of Flint learned that lead had contaminated their water system, the local government made water-testing kits available to them free of charge. The city government published the results of these tests, creating a valuable dataset that is key to understanding the causes and extent of the lead contamination event in Flint. This is the nation's largest dataset on lead in a municipal water system. In this paper, we predict the lead contamination for each household's water supply, and we study several related aspects of Flint's water troubles, many of which generalize well beyond this one city. For example, we show that elevated lead risks can be (weakly) predicted from observable home attributes. Then we explore the factors associated with elevated lead. These risk assessments were developed in part via a crowd sourced prediction challenge at the University of Michigan. To inform Flint residents of these assessments, they have been incorporated into a web and mobile application funded by \texttt{Google.org}. We also explore questions of self-selection in the residential testing program, examining which factors are linked to when and how frequently residents voluntarily sample their water.Comment: Applied Data Science track paper at KDD 2017. For associated promotional video, see https://www.youtube.com/watch?v=0g66ImaV8A

Expression patterns of FLAGELLIN SENSING 2 map to bacterial entry sites in plant shoots and roots

Expression of the flagellin receptor FLS2 is regulated in a cell/tissue-specific and stress-induced manner that correlated with sites of bacterial infection. The vasculature expresses FLS2 and responds to flagelli

ELF3 controls thermoresponsive growth in Arabidopsis

Plant development is highly responsive to ambient temperature, and this trait has been linked to the ability of plants to adapt to climate change [1]. The mechanisms by which natural populations modulate their thermoresponsiveness are not known [2]. To address this, we surveyed Arabidopsis accessions for variation in thermal responsiveness of elongation growth and mapped the corresponding loci. We find that the transcriptional regulator EARLY FLOWERING3 (ELF3) controls elongation growth in response to temperature. Through a combination of modeling and experiments, we show that high temperature relieves the gating of growth at night, highlighting the importance of temperature-dependent repressors of growth. ELF3 gating of transcriptional targets responds rapidly and reversibly to changes in temperature. We show that the binding of ELF3 to target promoters is temperature dependent, suggesting a mechanism where temperature directly controls ELF3 activity

Recent advances in understanding regulation of the Arabidopsis circadian clock by local cellular environment.

Circadian clocks have evolved to synchronise an organism's physiology with the environmental rhythms driven by the Earth's rotation on its axis. Over the past two decades, many of the genetic components of the Arabidopsis thaliana circadian oscillator have been identified. The interactions between these components have been formulized into mathematical models that describe the transcriptional translational feedback loops of the oscillator. More recently, focus has turned to the regulation and functions of the circadian clock. These studies have shown that the system dynamically responds to environmental signals and small molecules. We describe advances that have been made in discovering the cellular mechanisms by which signals regulate the circadian oscillator of Arabidopsis in the context of tissue-specific regulation