Framing the Social Security Earnings Test

In the U.S. Social Security system, the decision of when to claim Social Security benefits is legally independent of when the individual chooses to separate from the workforce. But if an individual claims benefits prior to his “full retirement age” (FRA) while continuing to have labor earnings above a relatively low threshold, his benefits are reduced via the Social Security Earnings Test. The individual is compensated for this benefit reduction in the form of higher benefit payments payable from the FRA for the remainder of the beneficiary’s lifetime. To the extent that the relevant actuarial adjustment is actuarially fair, the Earnings Test simply represents a re-timing of benefit payments. Nevertheless, many people view the benefit reduction as a tax on earned income after claiming benefits. We posit that whether the Earnings Test influences work and benefit claiming patterns will depend on whether people are aware of the benefit enhancements paid in return for continued work. Using an experimental module of the RAND American Life Panel, we explore how people perceive the Social Security Earnings Test and examine alternative ways to frame the tradeoff between reduced benefits in the short run and higher benefits paid later and for life. Our overall finding is that knowledge of the Earnings Test is uneven, with better educated, higher earning, older individuals showing somewhat greater knowledge than others. The frames we have tested produce only minor effects on individual choices of earnings or claiming ages, and the effects are difficult to reconcile with economic theory

Targeted Genome-Wide Enrichment of Functional Regions

Only a small fraction of large genomes such as that of the human contains the functional regions such as the exons, promoters, and polyA sites. A platform technique for selective enrichment of functional genomic regions will enable several next-generation sequencing applications that include the discovery of causal mutations for disease and drug response. Here, we describe a powerful platform technique, termed “functional genomic fingerprinting” (FGF), for the multiplexed genomewide isolation and analysis of targeted regions such as the exome, promoterome, or exon splice enhancers. The technique employs a fixed part of a uniquely designed Fixed-Randomized primer, while the randomized part contains all the possible sequence permutations. The Fixed-Randomized primers bind with full sequence complementarity at multiple sites where the fixed sequence (such as the splice signals) occurs within the genome, and multiplex amplify many regions bounded by the fixed sequences (e.g., exons). Notably, validation of this technique using cardiac myosin binding protein-C (MYBPC3) gene as an example strongly supports the application and efficacy of this method. Further, assisted by genomewide computational analyses of such sequences, the FGF technique may provide a unique platform for high-throughput sample production and analysis of targeted genomic regions by the next-generation sequencing techniques, with powerful applications in discovering disease and drug response genes

Tuning the Surface Plasmon Resonance of Lanthanum Hexaboride to Absorb Solar Heat: A Review

While traditional noble metal (Ag, Au, and Cu) nanoparticles are well known for their plasmonic properties, they typically only absorb in the ultraviolet and visible regions. The study of metal hexaborides, lanthanum hexaboride (LaB6) in particular, expands the available absorbance range of these metals well into the near-infrared. As a result, LaB6 has become a material of interest for its energy and heat absorption properties, most notably to those trying to absorb solar heat. Given the growing popularity of LaB6, this review focuses on the advances made in the past decade with respect to controlling the plasmonic properties of LaB6 nanoparticles. This review discusses the fundamental structure of LaB6 and explains how decreasing the nanoparticle size changes the atomic vibrations on the surface and thus the plasmonic absorbance band. We explain how doping LaB6 nanoparticles with lanthanide metals (Y, Sm, and Eu) red-shifts the absorbance band and describe research focusing on the correlation between size dependent and morphological effects on the surface plasmon resonance. This work also describes successes that have been made in dispersing LaB6 nanoparticles for various optical applications, highlighting the most difficult challenges encountered in this field of study

The design and implementation of checkpoint/restart process fault tolerance for Open MPI

To be able to fully exploit ever larger computing platforms, modern HPC applications and system software must be able to tolerate inevitable faults. Historically, MPI implementations that incorporated fault tolerance capabilities have been limited by lack of modularity, scalability and usability. This paper presents the design and implementation of an infrastructure to support checkpoint/restart fault tolerance in the Open MPI project. We identify the general capabilities required for distributed checkpoint/restart and realize these capabilities as extensible frameworks within Open MPI’s modular component architecture. Our design features an abstract interface for providing and accessing fault tolerance services without sacrificing performance, robustness, or flexibility. Although our implementation includes support for some initial checkpoint/restart mechanisms, the framework is meant to be extensible and to encourage experimentation of alternative techniques within a production quality MPI implementation. 1

Moving the Plasmon of LaB₆ from IR to Near-IR via Eu-Doping.

Lanthanum hexaboride (LaB₆) has become a material of intense interest in recent years due to its low work function, thermal stability and intriguing optical properties. LaB₆ is also a semiconductor plasmonic material with the ability to support strong plasmon modes. Some of these modes uniquely stretch into the infrared, allowing the material to absorb around 1000 nm, which is of great interest to the window industry. It is well known that the plasmon of LaB₆ can be tuned by controlling particle size and shape. In this work, we explore the options available to further tune the optical properties by describing how metal vacancies and Eu doping concentrations are additional knobs for tuning the absorbance from the near-IR to far-IR in La1-xEuxB₆ (x = 0, 0.2, 0.5, 0.8, and 1.0). We also report that there is a direct correlation between Eu concentration and metal vacancies within the Eu1-xLaxB₆

Moving the Plasmon of LaB6 from IR to Near-IR via Eu-Doping

Lanthanum hexaboride (LaB6) has become a material of intense interest in recent years due to its low work function, thermal stability and intriguing optical properties. LaB6 is also a semiconductor plasmonic material with the ability to support strong plasmon modes. Some of these modes uniquely stretch into the infrared, allowing the material to absorb around 1000 nm, which is of great interest to the window industry. It is well known that the plasmon of LaB6 can be tuned by controlling particle size and shape. In this work, we explore the options available to further tune the optical properties by describing how metal vacancies and Eu doping concentrations are additional knobs for tuning the absorbance from the near-IR to far-IR in La1−xEuxB6 (x = 0, 0.2, 0.5, 0.8, and 1.0). We also report that there is a direct correlation between Eu concentration and metal vacancies within the Eu1−xLaxB6

Effects of Size and Structural Defects on the Vibrational Properties of Lanthanum Hexaboride Nanocrystals

Lanthanum hexaboride (LaB₆) is notable for its thermionic emission and mechanical strength and is being explored for its potential applications in IR-absorbing photovoltaic cells and thermally insulating window coatings. Previous studies have not investigated how the properties of LaB₆ change on the nanoscale. Despite interest in the tunable plasmonic properties of nanocrystalline LaB₆, studies have been limited due to challenges in the synthesis of phase-pure, size-controlled, high-purity nanocrystals without high temperatures or pressures. Here, we report, for the first time, the ability to control particle size and boron content through reaction temperature and heating ramp rate, which allows the effects of size and defects on the vibrational modes of the nanocrystals to be studied independently. Understanding these effects is important to develop methods to fully control the properties of nanocrystalline LaB₆, such as IR absorbance. In contrast to previous studies on stoichiometric LaB₆ nanocrystals, we report here that boron content and lanthanum vacancies have a greater influence on their vibrational properties than their particle size