A Misguided Tobacco Policy? Public Policy and Consumption Substitutability Between Cigarettes and An Important Smokeless Tobacco Alternative

Snus, Tobacco, Smokeless Tobacco, Agricultural and Food Policy, Health Economics and Policy,

Encouraging New Hires to Save for Retirement

This project examines the impact of employer-provided financial education for newly hired workers on contributions to voluntary retirement savings plans. Using administrative data from five large employers, the researchers assess the impact of information and delivery methods on the choice to participate in the plans and the deferral amount selected. The researchers collected additional data from one employer-partner covering the two years before and after their automatic enrollment policy was implemented. Average participation rates increased sharply, while the same fraction of workers took advantage of the full employer match once eligible. The researchers also conducted a survey of newly hired workers. The survey measured employees’ understanding of their company’s voluntary retirement savings plan, their assessment of the employer-provided information, and their reasons for limited or non-participation. Nonparticipants demonstrated lower overall financial literacy relative to participants, and many respondents felt that the information provided by their employers was not sufficient. Finally, the largest employer-partner, BB&T, implemented a field experiment where an on-line mailing was sent to a random subset of non-participating newly hired workers. Younger workers receiving the flyer were significantly more likely to enroll in the 401(k) plan, while older workers actually had lower initiation rates relative to their control group. The research presented provides insights into the efficacy and importance of financial education provided by employers to newly hired workers and how it impacts their retirement saving decisions.

Escherichia coli 30S ribosomal subunit assembly: a novel role for the DnaK chaperone system

The prokaryotic ribosome is a 2.5 MDa particle comprised of two asymmetric subunits, the large (50S) and small (30S) subunits. The large subunit contains two RNAs (5S and 23S) in addition to thirty-four proteins. The small subunit consists of one RNA (16S rRNA) and twenty-one proteins. Although the crystal structure has been solved, much remains to be revealed concerning the assembly of this macromolecular structure. Our laboratory is focused on the assembly of the small subunit. In vitro assembly of this structure was achieved in the late 1960\u27s and early 1970\u27s. At low temperature when 16S rRNA and all of the small subunit proteins are incubated together, only a subset of the proteins are able to associate with the RNA and a particle termed Reconstitution Intermediate (RI, 21S) results. When RI particles are heat treated, a conformational rearrangement occurs and RI* (26S) particles result that are capable of complete assembly with the remainder of the small subunit proteins, even at low temperature, to form functional 30S subunits. In vitro 30S subunit assembly requires long incubation periods, high ionic strength, and heat treatment. In light of these strict requirements, we hypothesized that assembly factors must exist in vivo to facilitate this crucial assembly process, making it accurate and efficient. We have identified the DnaK chaperone system as one such factor. The purified DnaK chaperone system is sufficient to facilitate in vitro 30S subunit assembly at low temperature, forming 30S particles that co-sediment, have the same protein complement, bind tRNA, and participate in polyphenylalanine synthesis like 30S subunits. Additionally, the association behavior of the DnaK chaperone system components with pre-30S particles in vitro was observed and found to be very similar to their association with substrate in their well-characterized protein folding role. Lastly, it was determined that DnaK binds small subunit components in vivo, including pre-processed 16S rRNA. This is the first evidence clearly demonstrating a direct link between the DnaK chaperone system and the assembly of ribosomes in E. coli, and the first instance in which an extra-ribosomal assembly factor has been shown to facilitate 30S subunit assembly in vitro

Angle-Beam Shear Wave Scattering from Buried Crack-like Defects in Bonded Specimens

Ultrasonic wavefield imaging, which refers to the measurement of wave motion on a 2-D rectilinear grid resulting from a fixed source, has been previously applied to angle-beam shear wave propagation in simple plates with through-holes and far-surface notches [1]. In this prior work scattered waves were analyzed using baseline subtraction of wavefields acquired before and after a notch was introduced [2]. In practice, however, defects of interest often occur between bonded layers and it is generally not possible to record data from the same specimen in both the undamaged and damaged states, making direct baseline subtraction infeasible. This present work considers measurement of angle-beam waves in several bonded specimens with and without buried defects originating from fastener holes. The experimental methodology is explained, which includes specimen fabrication details and wavefield measurement methods. Data from fastener holes with and without simulated damage in the form of notches are compared, and techniques used to analyze differences are discussed. Despite unavoidable deviations from specimen-to-specimen caused by factors such as variations in bonding, transducer mounting, and fastener hole machining, it is shown that scattering from buried notches can be clearly visualized in the recorded wavefield data

Evaluating the Quick Fix: Weight Loss Drugs and Cellular Respiration

One key to student success in introductory and cell biology courses is a foundational knowledge of cellular respiration. This is a content area in which students often harbor misconceptions that make cellular respiration particularly challenging to teach. Conventional approaches presenting cellular respiration as a complex series of isolated steps creates a situation where students tend to memorize the steps but fail to appreciate the bigger picture of how cells transform and utilize energy. Instructors frequently struggle to find ways to motivate students and encourage deeper learning. The learning goals of this cellular respiration lesson are to understand energy transfer in a biological system, develop data analysis skills, practice hypothesis generation, and appreciate the importance of cellular respiration in everyday life. These goals are achieved by using a case study as the focal point. The case-based lesson is supported with student-centered instructional strategies, such as individual and group activity sheets, in-class group discussions and debate, and in-class clicker questions. This lesson has been implemented at two institutions in large enrollment introductory biology courses and in a smaller upper-division biochemistry course

The Small-Scale Dynamo and Non-Ideal MHD in Primordial Star Formation

We study the amplification of magnetic fields during the formation of primordial halos. The turbulence generated by gravitational infall motions during the formation of the first stars and galaxies can amplify magnetic fields very efficiently and on short timescales up to dynamically significant values. Using the Kazantsev theory, which describes the so-called small-scale dynamo - a magnetohydrodynamical process converting kinetic energy from turbulence into magnetic energy - we can then calculate the growth rate of the small-scale magnetic field. Our calculations are based on a detailed chemical network and we include non-ideal magnetohydrodynamical effects such as ambipolar diffusion and Ohmic dissipation. We follow the evolution of the magnetic field up to larger scales until saturation occurs on the Jeans scale. Assuming a weak magnetic seed field generated by the Biermann battery process, both Burgers and Kolmogorov turbulence lead to saturation within a rather small density range. Such fields are likely to become relevant after the formation of a protostellar disk and, thus, could influence the formation of the first stars and galaxies in the Universe.Comment: 10 pages, 8 figures, ApJ accepte

Photometric characterization of Lucideon and Avian Technologies color standards including application for calibration of the Mastcam-Z instrument on the Mars 2020 rover

Several commercially available color standards exist, generated by a variety of manufacturers including LabSphere, Lucideon, and Avian Technologies. Previous work has characterized the photometric properties of LabSphere Spectralon targets. Here, we measure the visible and shortwave infrared (VSWIR; 0.4 to 2.5  μm) reflectance at multiple angles and determine the photometric properties of materials manufactured by Lucideon and Avian Technologies for potential use as calibration target materials for the Mars 2020 Mastcam-Z instrument. The Lucideon black, gray 33, green, and cyan samples are found to be significantly forward scattering. The yellow, red, and gray 70 samples are found to be weakly forward scattering. The Avian Technologies AluWhite98 sample was found to be weakly backward scattering. We characterize the absorptions observable and note the occurrence of wavelength-dependent photometric properties. The reflectance and photometric data collected and released here enable the use of these color standards for calibration of data from Mastcam-Z and other Mars-2020 rover instruments as well as provide key information for many other imaging and spectroscopy applications that require the calibration of data from multiple lighting or viewing geometries

The pseudo-mitochondrial genome influences mistakes in heteroplasmy interpretation

BACKGROUND: Nuclear mitochondrial pseudogenes (numts) are a potential source of contamination during mitochondrial DNA PCR amplification. This possibility warrants careful experimental design and cautious interpretation of heteroplasmic results. RESULTS: Here we report the cloning and sequencing of numts loci, amplified from human tissue and rho-zero (ρ(0)) cells (control) with primers known to amplify the mitochondrial genome. This paper is the first to fully sequence 46 paralogous nuclear DNA fragments that represent the entire mitochondrial genome. This is a surprisingly small number due primarily to the primer sets used in this study, because prior to this, BLAST searches have suggested that nuclear DNA harbors between 400 to 1,500 paralogous mitochondrial DNA fragments. Our results indicate that multiple numts were amplified simultaneously with the mitochondrial genome and increased the load of pseudogene signal in PCR reactions. Further, the entire mitochondrial genome was represented by multiple copies of paralogous nuclear sequences. CONCLUSION: These findings suggest that mitochondrial genome disease-associated biomarkers must be rigorously authenticated to preclude any affiliation with paralogous nuclear pseudogenes. Importantly, the common perception that mitochondrial template "swamps" numts loci precluding detectable amplification, depends on the region of the mitochondrial genome targeted by the PCR reaction and the number of pseudogene loci that may co-amplify. Cloning and relevant sequencing data will facilitate the correct interpretation. This is the first complete, wet-lab characterization of numts that represent the entire mitochondrial genome