Emily Martin

Demonstration of a near-IR line-referenced electro-optical laser frequency comb for precision radial velocity measurements in astronomy

An important technique for discovering and characterizing planets beyond our solar system relies upon measurement of weak Doppler shifts in the spectra of host stars induced by the influence of orbiting planets. A recent advance has been the introduction of optical frequency combs as frequency references. Frequency combs produce a series of equally spaced reference frequencies and they offer extreme accuracy and spectral grasp that can potentially revolutionize exoplanet detection. Here we demonstrate a laser frequency comb using an alternate comb generation method based on electro-optical modulation, with the comb centre wavelength stabilized to a molecular or atomic reference. In contrast to mode-locked combs, the line spacing is readily resolvable using typical astronomical grating spectrographs. Built using commercial off-the-shelf components, the instrument is relatively simple and reliable. Proof of concept experiments operated at near-infrared wavelengths were carried out at the NASA Infrared Telescope Facility and the Keck-II telescope.We describe a successful effort to produce a laser comb around 1.55 μm in the astronomical H band (1.5-1.8 μm) using a method based on a line-referenced, electrooptical-modulation frequency comb (LR-EOFC). We discuss the experimental setup, laboratory results and proof of concept demonstrations at the NASA Infrared Telescope Facility (IRTF) and the Keck-II telescope. The laser comb has a demonstrated stability of < 200 kHz, corresponding to a Doppler precision of ∼ 0.3 m s−1. This technology, when coupled with a high spectral resolution spectrograph, offers the promise of ∼ 1 m s−1 radial velocity precision suitable for the detection of Earth-sized planets in the habitable zones of cool M-type stars. ar X iv :1 50 1. 02 50 9v 1 [ as tr oph .I M ] 1 1 Ja n 20 15

Alcohol Marketing on Twitter and Instagram: Evidence of Directly Advertising to Youth/Adolescents.

AIMS Assess whether alcohol companies restrict youth/adolescent access, interaction, and exposure to their marketing on Twitter and Instagram. METHODS Employed five fictitious male and female Twitter (n = 10) and Instagram (n = 10) user profiles aged 13, 15, 17, 19 and/or 21. Using cellular smartphones, we determined whether profiles could (a) interact with advertising content-e.g. retweet, view video or picture content, comment, share URL; and/or (b) follow and directly receive advertising material updates from the official Instagram and Twitter pages of 22 alcohol brands for 30 days. RESULTS All user profiles could fully access, view, and interact with alcohol industry content posted on Instagram and Twitter. Twitters age-gate, which restricts access for those under 21, successfully prevented underage profiles from following and subsequently receiving promotional material/updates. The two 21+ profiles collectively received 1836 alcohol-related tweets within 30 days. All Instagram profiles, however, were able to follow all alcohol brand pages and received an average of 362 advertisements within 30 days. The quantity of promotional updates increased throughout the week, reaching their peak on Thursday and Friday. Representatives/controllers of alcohol brand Instagram pages would respond directly to our underage users comments. CONCLUSION The alcohol industry is in violation of their proposed self-regulation guidelines for digital marketing communications on Instagram. While Twitters age-gate effectively blocked direct to phone updates, unhindered access to post was possible. Everyday our fictitious profiles, even those as young as 13, were bombarded with alcohol industry messages and promotional material directly to their smartphones.

VIRUS Instrument Collimator Assembly

The Visual Integral-Field Replicable Unit Spectrograph (VIRUS) instrument is a baseline array 150 identical fiber fed optical spectrographs designed to support observations for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). The collimator subassemblies of the instrument have been assembled in a production line and are now complete. Here we review the design choices and assembly practices used to produce a suite of identical low-cost spectrographs in a timely fashion using primarily unskilled labor.

Within-House Spatial Distribution of Fecal Indicator Bacteria in Poultry Litter

Land application of poultry litter is often considered to be a major source of water pollutants in poultry-producing regions. However, reported levels of fecal indicator microorganisms in litter vary widely, with considerable variation possible within houses and across farms, depending on management practices. Therefore, a study was conducted to determine the levels and distribution of indicator microorganisms within 12 broiler farms representing three companies. Within each house, litter samples were collected from around the feed line, water line, north wall, cool pad end, middle, and fan end. Litter moisture content was significantly different within the houses, with the litter being driest around the feed line (19.8%) and wettest around the water line (40.7%). Mean levels of total coliforms, , enterococci, and were 3.7, 3.3, 6.4, and 4.0 log colony-forming units g dry litter, respectively. Levels of total coliforms, , and were positively correlated with litter moisture content, but enterococci levels were not. Consequently, levels of total coliforms, , and , as well as enterococci, were highest around the water line and lowest around the feed line. These results indicate that areas with higher litter water content are more likely to contain higher levels of most fecal indicator microorganisms. Approaches to reduce litter water content in these areas would not only benefit the microbial quality of litter for land application but would also likely improve in-house disease control.

An overview of the NIRSPEC upgrade for the Keck II telescope

NIRSPEC is a 1-5 um echelle spectrograph in use on the Keck II Telescope since 1999. The spectrograph is capable of both moderate (R=λ/▵λ~2000) and high (R~25,000) resolution observations and has been a workhorse instrument across many astronomical fields, from planetary science to extragalactic observations. In the latter half of 2018, we will upgrade NIRSPEC to improve the sensitivity and stability of the instrument and increase its lifetime. The major components of the upgrade include replacing the spectrometer and slit-viewing camera detectors with Teledyne H2RG arrays and replacing all transputer-based electronics. We present detailed design, testing, and analysis of the upgraded instrument, including the finalized optomechanical design of the new 1-5 μm slit-viewing camera, detector characterization of the science and Engineering A grade arrays, electronics systems, and updated software design. The optomechanical design of the slit-viewing camera and replacement detector head assembly have both been assembled and cold-tested in our lab. We also show results from the GigE interface to the SAM/ASIC boards to control the H2RG. The upgrade will continue NIRSPEC’s legacy as a powerful near-infrared spectrograph behind one of the world’s most scientifically productive telescopes.

Qualitative Analysis of Partnerships’ Effect on Implementation of a Nationally Led Community-Based Initiative

Introduction. The American Heart Association (AHA) was funded to implement a nationally led initiative to implement policy, systems, and environment (PSE) interventions in communities across the United States. In Cohort 1, 15 communities were tasked with working with local community partners to plan and implement initiatives. Method. Engaged as the evaluators, Texas A&M researchers conducted telephone interviews with project managers (employed by AHA) and community partners representing the 15 communities. Interviewees were asked questions pertaining to partnership planning and involvement in initiatives and overall perceptions of the impact of the program. Interviews were analyzed qualitatively using the Consolidated Framework for Implementation Research as the guiding framework. Results. Thematic analysis revealed that partners were used in planning and implementing initiatives and felt that initiatives were successful in building community engagement. Some noted success in PSE changes, although this was not a major focus of respondents, regardless of it being a main indicator for the funder. Discussion. Themes reveal several recommendations for those embarking on community-level work. Those recommendations include (1) build on existing priorities, (2) focus on incremental steps that build toward the bigger goal, (3) use national organizations to move more quickly, and (4) leverage resources through collaborative efforts.

Implementation of Policy, Systems, and Environmental Community-Based Interventions for Cardiovascular Health Through a National Not-for-Profit: A Multiple Case Study

Introduction. In 2014, the Centers for Disease Control and Prevention funded the American Heart Association to implement policy, systems, and environment-focused strategies targeting access to healthy food and beverages, physical activity, and smoke-free environments. Method. To understand factors affecting implementation and variations in success across sites, evaluators conducted a multiple case study. Based on past literature, community sites were categorized as capacity-building or implementation-ready, for comparison. A sample of six communities were selected using a systematic selection tool. Through site visits, evaluators conducted interviews with program staff and community partners and assessed action plans. Results. Evaluators identified important implications for nationally coordinated community-based prevention programming. Differences in implementation varied by the communities’ readiness, with the most notable differences in how they planned activities and defined success. Existing partner relationships (or lack thereof) played a significant role, regardless of the American Heart Association’s existing presence within the communities, in the progression of initiatives and the differences observed among phases. Last, goals in capacity-building sites were tied to organizational goals while goals in implementation-ready sites were more incremental with increased community influence and buy-in. Discussion. Using national organizations as a mechanism to carry out large-scale community-based prevention work is a viable option that provides coordinated, wide-scale implementation without sacrificing a community’s priorities or input. In funding future initiatives, the presence of relationships and the time needed to cultivate such relationships should be accounted for in the planning and implementation processes, as well as both local and national expectations.

Effects of Dairy Manure Management Practices on E. coli Concentration and Diversity

Dairy cattle manure has been implicated as a major source of fecal contamination in non-point source agricultural runoff in watersheds. Four different dairy farms in central Texas, each utilizing a different dairy manure management practice, in the Leon River watershed were sampled for E. coli using EPA Method 1603, with a percentage of isolates genotyped and phylotyped using the Clermont quadruplex PCR method. E. coli concentration was reduced as manure moved through the management process with tiered management systems lowering concentration the most. E. coli genotypes showed no correlation with sampling season or management practice. The highest percentage of unique genotypes was observed in dairy 2, which consisted of a settling basin then lagoon. One genotype was seen across all dairies and composed 15% of all genotypes characterized. E. coli phylotypes showed no seasonal or management practice trend. B1 was the most common phylotype isolated from all dairies and time periods, which was expected. Potentially pathogenic phylotypes were rarely observed, which could indicate isolation from pathogenic E. coli introduction. Dairy manure management practices that separate solid from liquid waste reduced E. coli concentrations the most based on these results.

Optical design of a red-sensitive spectrograph

We present a preliminary design for a red-sensitive spectrograph. The spectrograph is optimized to operate over the 600- 1000 nm spectral range at a resolution of R = λ/▵λ ~2000 and is designed specifically for the 2.7-m Harlan J. Smith Telescope at McDonald Observatory. The design is compact and cost effective and should have very high throughput. The principles of the design can be extended to other purposes, such as a unit spectrograph for the DESpec project or other projects that require good performance in the red. In this paper, we will discuss the selection of components as well as the choice of optical layouts and the theoretical throughput of the instrument.