Coherent Excitation of the 6S1/2 to 5D3/2 Electric Quadrupole Transition in 138Ba+

The electric dipole-forbidden, quadrupole 6S1/2 5D3/2 transition in Ba+ near 2051 nm, with a natural linewidth of 13 mHz, is attractive for potential observation of parity non-conservation, and also as a clock transition for a barium ion optical frequency standard. This transition also offers a direct means of populating the metastable 5D3/2 state to measure the nuclear magnetic octupole moment in the odd barium isotopes. Light from a diode-pumped, solid state Tm,Ho:YLF laser operating at 2051 nm is used to coherently drive this transition between resolved Zeeman levels in a single trapped 138Ba+ ion. The frequency of the laser is stabilized to a high finesse Fabry Perot cavity at 1025 nm after being frequency doubled. Rabi oscillations on this transition indicate a laser-ion coherence time of 3 ms, most likely limited by ambient magnetic field fluctuations.Comment: 5 pages, 5 figure

A Longitudinal Examination of Racial Centrality in African American Youth and Parents

For most African Americans, racial identity is an important aspect of their individual identity. Racial centrality, a dimension of racial identity, is protective of psychosocial well-being among African Americans. The current study explored the stability of racial centrality in African American youth and their parents, and the relationship between parent and child racial centrality across time. African American youth (N = 379) and parents completed surveys when youth were enrolled in Grades 5, 7, 10, and 12. Results indicated that individual differences in parents' and youths' racial centrality were stable across time. Although bivariate correlations confirmed positive relationships between parents' and youths' identity after Grade 7, only a few of these relationships were significant in cross-lag panel analyses. Results provide novel insight about the development and stability of racial centrality in African American youth and the effect that parents have in shaping their children's racial identity.Master of Art

A Time-Dependent Method of Characteristics Formulation with Time Derivative Propagation.

We developed a new time-dependent neutron transport method for nuclear reactor kinetics using method of characteristics (MOC) with angular flux time derivative propagation. In contrast to conventional time integration methods which use local finite difference approximations to treat the time derivative, the new method solves for the spatially-dependent angular flux time derivative by propagation along characteristics in space. This results in the angular flux time derivative being recast in terms of the neutron source time derivatives, and thus the new method is called Source Derivative Propagation (SDP). We developed three SDP methods using different approximations, and they require much less memory than the conventional methods. For SDP, we approximate the source derivatives using backward differences. This is analogous to the backward differentiation formula (BDF), and our results confirmed that the high-order SDP approximations reproduced the high-order angular flux derivative approximation of equivalent order BDF. We assessed SDP by comparison to conventional time-dependent MOC methods. This included both a reference method (RBDC) which stored the angular flux and a popular approximate method (IBDC). We performed error analysis for SDP, RBDC, and IBDC. This informed the refinement of the SDP methods, and clarified when SDP will be accurate. We tested SDP using the computer code DeCART, which was used to model three transients based on the TWIGL and C5G7 benchmarks. A fine time step reference solution was generated using RBDC. The SDP methods converged to the reference when the time step was refined and the BDF order increased. In addition, we observed that SDP accurately replicated the RBDC solution when the same time step and BDF order was used. This indicates that the propagated angular flux time derivative of SDP reproduced the RBDC angular flux derivative. SDP was much more accurate than the IBDC. We assessed the efficiency of SDP by comparing the run-time and memory requirements to RBDC and IBDC. SDP required slightly more memory and run-time than IBDC, but much less memory than RBDC. Our results demonstrate that, for the problems tested, SDP can efficiently and accurately solve the time-dependent transport equation for reactor kinetics without excessive memory.PhDNuclear Engineering & Radiological SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/102321/1/adamhoff_1.pd

Progress Report: Effects of Condensed Corn Distillers Solubles on Steer Performance and Carcass Composition

Condensed, corn, distillers solubles provides an effective energy supplement for finishing cattle across a number of finishing systems

Progress Report: Pasture Finishing of Beef Steers Using Contemporary Feedlot Protocols

Environmental regulations in Iowa can place animal population restrictions on a given site. This study explores the possibility of finishing cattle in a remote pasture location to handle an overflow of animals and yet remain in compliance with environmental mandates

Assessing adolescents' critical health literacy: How is trust in government leadership associated with knowledge of COVID-19?

This study explored relations between COVID-19 news source, trust in COVID-19 information source, and COVID-19 health literacy in 194 STEM-oriented adolescents and young adults from the US and the UK. Analyses suggest that adolescents use both traditional news (e.g., TV or newspapers) and social media news to acquire information about COVID-19 and have average levels of COVID-19 health literacy. Hierarchical linear regression analyses suggest that the association between traditional news media and COVID-19 health literacy depends on participants' level of trust in their government leader. For youth in both the US and the UK who used traditional media for information about COVID-19 and who have higher trust in their respective government leader (i.e., former US President Donald Trump and UK Prime Minister Boris Johnson) had lower COVID-19 health literacy. Results highlight how youth are learning about the pandemic and the importance of not only considering their information source, but also their levels of trust in their government leaders

Mediators of Monocyte Migration in Response to Recovery Modalities following Resistance Exercise

Mediators of monocyte migration, complement receptor-3 (CR3), and chemokine ligand-4 (CCL4) were measured in response to recovery modalities following resistance exercise. Thirty resistance-trained men (23.1 +/- 2.9 y; 175.2 +/- 7.1 cm; 82.1 +/- 8.4 kg) were given neuromuscular electric stimulation (NMES), cold water immersion (CWI), or control (CON) treatments immediately following resistance exercise. Blood samples were obtained preexercise (PRE), immediately (IP), 30 minutes (30 P), 24 hours (24 H), and 48 hours (48 H) after exercise for measurement of circulating CCL4 and CR3 expression on CD14+ monocytes, by assay and flow cytometry. Circulating CCL4 showed no consistent changes. Inferential analysis indicated that CR3 expression was likely greater in CON at 30 P than NMES (90.0%) or CWI (86.8%). NMES was likely lower than CON at 24H (92.9%) and very likely lower at 48H (98.7%). Expression of CR3 following CWI was very likely greater than CON (96.5%) at 24H. The proportion of CR3+ monocytes was likely greater following CWI than NMES (85.8%) or CON (85.2%) at 24 H. The change in proportion of CR3+ monocytes was likely (86.4%) greater following NMES than CON from IP to 30 P. The increased expression of CR3 and increased proportion of CR3+ monocytes following CWI at 24 H indicate a potentially improved ability for monocyte adhesion to the endothelium, possibly improving phagocytosis of damaged tissues

Quantifying Laryngopharyngeal Reflux in Singers: Perceptual and Objective Findings

This study examines the relationship between laryngopharyngeal reflux (LPR) symptoms and oropharyngeal pH levels in singers. We hypothesized that reported symptoms would correlate with objective measures of pH levels from the oropharynx, including the number and total duration of reflux episodes. Twenty professional/semiprofessional singers completed the Reflux Symptom Index (RSI) and underwent oropharyngeal pH monitoring. Mild, moderate, or severe pH exposure was recorded during oropharyngeal pH monitoring. Correlations were performed to examine potential relationships between reflux symptoms and duration of LPR episodes. Symptom severity did not correlate with pH levels; however, we found a number of covariances of interest. Large sample sizes are necessary to determine if true correlations exist. Our results suggest that singers may exhibit enhanced sensitivity to LPR and may therefore manifest symptoms, even in response to subtle changes in pH. This study emphasizes the importance of sensitive and objective measures of reflux severity as well as consideration of the cumulative time of reflux exposure in addition to the number of reflux episodes

Effects of Functional Oils and Monensin Alone or in Combination on Feedlot Cattle Growth and Carcass Composition (Progress Report)

This report represents the first trial of a study consisting of a commercial mixture of functional oils (Essential, Oligo Basics USA LLC, Wilmington, DE) used alone and in combination with Monensin to evaluate the effects on steers performance when fed a high concentrate diet. One hundred and twenty steers, average initial weight 322 kg, were divided into five treatments with four pens per treatment and six steers per pen. The treatments were Control (C), Monensin (223 mg/hd/d) (M), Monensin (223 mg/hd/d) + Essential (250 mg/kg DMI) (ME), Essential Low (250 mg/kg DMI) (EL), and Essential High (500 mg/kg DMI) (EH). All steers were fed the same diet on an ad libitum basis, treatments M and EL for 172 days and treatments C, ME, and EH for 179 days. Steers were harvested at an average weight of 617 kg. Results to date suggest that cattle provided functional oils in their diet perform equally as well in the feedyard and in carcass composition as cattle provided a more traditional ionophore in their diet

Progress Report: Effects of Condensed Corn Distillers Solubles on Steer Performance and Carcass Composition

This study looked at the use of condensed corn distillers solubles (CCDS) as a feed source for steers backgrounded on pasture as well as steers being fed in the feedlot. In addition, a treatment group was finished on pasture with CCDS as a part of their ration. The two feedlot rations were isocaloric and isonitrogenous. The pasture finishing steers were fed a ration based on the feedlot ration containing CCDS but were not fed any hay. The goal of this study was to establish the benefits, as well as the limitations, of feeding CCDS to feedlot and backgrounded steers