Mechanical Engineering Design Project report: Enabler control systems

The Controls Group was assigned the responsibility for designing the Enabler's control system. The requirement for the design was that the control system must provide a simple user interface to control the boom articulation joints, chassis articulation joints, and the wheel drive. The system required controlling hydraulic motors on the Enabler by implementing 8-bit microprocessor boards. In addition, feedback to evaluate positions and velocities must be interfaced to provide the operator with confirmation as well as control

Dietary Intakes of Children From Food Insecure Households

The objective of this cross-sectional study is to compare the dietary behaviors of children from low food secure (LFS) households with children from very low food secure (VLFS) households over an entire day, and during meals specifically consumed at home —breakfast, snack, and dinner. Parents of the recruited children completed a demographic questionnaire, along with USDA\u27s 6-item short form food security questionnaire. Children completed 24-hour dietary recalls in person. Complete data from 102 children 9 to 12 years old were used. Using ANOVA to assess the differences among groups in intakes over an entire day and during meals consumed at home, no significant differences were found, except for vitamin C intake during breakfast. Based on the definitions of LFS and VLFS, it was hypothesized that children from VLFS group would have lower dietary intakes compared to children from the LFS group. However, this study found little difference. Speculations have been made for these findings and implications for research have been presented

Differential Improvements in Student Fruit and Vegetable Selection and Consumption in Response to the New National School Lunch Program Regulations: A Pilot Study

Objective To investigate changes in student food selection and consumption in response to the new National School Lunch Program meal patterns during fall 2011. Design Eight elementary and four intermediate schools in one Houston area school district were matched on free/reduced-price meal eligibility and randomized into control or intervention conditions. Intervention Both intervention and control school cafeterias served the same menu. The intervention school cafeterias posted the new meal pattern daily; students could select one fruit and two vegetable servings per reimbursable meal. Control school students could only select the previous meal pattern: a total of two fruit and vegetable servings per meal. Main outcome measures Students were observed during lunch: student sex and foods selected/consumed were recorded. Diet analysis software was used to calculate energy/food groups selected/consumed. Statistical analyses performed Cochran-Mantel-Haenszel χ2 tests examined differences in the percent of students selecting each meal component by condition, controlling for sex, grade, and school free/reduced-price meal eligibility. Analysis of covariance assessed differences in amount of energy/food groups selected and consumed, and differences in percent of food groups consumed. Results Observations were conducted for 1,149 elementary and 427 intermediate students. Compared with students in the control schools, significantly more intervention elementary and intermediate school students selected total (P\u3c0.001, P\u3c0.05) and starchy vegetables (P\u3c0.001, P\u3c0.01); more intervention intermediate school students selected fruit (P\u3c0.001), legumes (P\u3c0.05), and protein foods (P\u3c0.01). There were significantly greater amounts of these foods selected and consumed, but no differences in the proportion of the foods consumed by condition. Fewer calories were consumed by elementary and intermediate school intervention students. Conclusions More intervention students selected fruit and vegetables at lunch and consumed them compared with control condition students. Future studies with larger and more diverse student populations are warranted

Outcome Evaluation of a Pilot Study Using “Nudges”

Background: Every school day, over 31 million U.S. children eat school lunches. Unfortunately, students often do not choose the healthy options in the school cafeteria. This paper describes outcome results of a pilot study using “nudges” to improve elementary school students’ fruits and vegetables selections. Methods: A pilot study was conducted from January to May 2012, in six intervention schools and 2 control schools. A behavioral economics-based intervention was conducted using “nudges” or cues from the cafeteria (staff encouragement to select fruit and vegetables, food labels, “Harvest of the Month” posters), school (morning announcement messages, prompts regarding cafeteria food selections), and parents (school newsletter articles, parent listserve messages) to promote students’ selection of fruits and vegetables in the school cafeteria. The serving data from the point-of-service machine provided fruits and vegetables served per student per day. Results:There were no significant differences in the number of servings of fruits and vegetables served per student per day, averaged over the study period. Process data revealed low implementation of the intervention components, which may partially explain results. Conclusions: Low implementation of nudges led to non-significant results in this pilot study. However, providing environmental cues are important and warrant further research with full implementation. Starting 2012, the new meal pattern includes two vegetables and a fruit serving for lunch; and two fruit servings for breakfast. Minimal cost interventions should be explored to facilitate successful implementation of new school meal guidelines

Radial Velocity Prospects Current and Future: A White Paper Report prepared by the Study Analysis Group 8 for the Exoplanet Program Analysis Group (ExoPAG)

[Abridged] The Study Analysis Group 8 of the NASA Exoplanet Analysis Group was convened to assess the current capabilities and the future potential of the precise radial velocity (PRV) method to advance the NASA goal to "search for planetary bodies and Earth-like planets in orbit around other stars.: (U.S. National Space Policy, June 28, 2010). PRVs complement other exoplanet detection methods, for example offering a direct path to obtaining the bulk density and thus the structure and composition of transiting exoplanets. Our analysis builds upon previous community input, including the ExoPlanet Community Report chapter on radial velocities in 2008, the 2010 Decadal Survey of Astronomy, the Penn State Precise Radial Velocities Workshop response to the Decadal Survey in 2010, and the NSF Portfolio Review in 2012. The radial-velocity detection of exoplanets is strongly endorsed by both the Astro 2010 Decadal Survey "New Worlds, New Horizons" and the NSF Portfolio Review, and the community has recommended robust investment in PRVs. The demands on telescope time for the above mission support, especially for systems of small planets, will exceed the number of nights available using instruments now in operation by a factor of at least several for TESS alone. Pushing down towards true Earth twins will require more photons (i.e. larger telescopes), more stable spectrographs than are currently available, better calibration, and better correction for stellar jitter. We outline four hypothetical situations for PRV work necessary to meet NASA mission exoplanet science objectives.Comment: ExoPAG SAG 8 final report, 112 pages, fixed author name onl

Precise Infrared Radial Velocities from Keck/NIRSPEC and the Search for Young Planets

We present a high-precision infrared radial velocity study of late-type stars using spectra obtained with NIRSPEC at the W. M. Keck Observatory. Radial velocity precisions of 50 m/s are achieved for old field mid-M dwarfs using telluric features for precise wavelength calibration. Using this technique, 20 young stars in the {\beta} Pic (age ~12 Myr) and TW Hya (age ~8 Myr) Associations were monitored over several years to search for low mass companions; we also included the chromospherically active field star GJ 873 (EV Lac) in this survey. Based on comparisons with previous optical observations of these young active stars, radial velocity measurements at infrared wavelengths mitigate the radial velocity noise caused by star spots by a factor of ~3. Nevertheless, star spot noise is still the dominant source of measurement error for young stars at 2.3 {\mu}m, and limits the precision to ~77 m/s for the slowest rotating stars (v sin i < 6 km/s), increasing to ~168 m/s for rapidly rotating stars (v sin i > 12 km/s). The observations reveal both GJ 3305 and TWA 23 to be single-lined spectroscopic binaries; in the case of GJ 3305, the motion is likely caused by its 0.09" companion, identified after this survey began. The large amplitude, short-timescale variations of TWA 13A are indicative of a hot Jupiter-like companion, but the available data are insufficient to confirm this. We label it as a candidate radial velocity variable. For the remainder of the sample, these observations exclude the presence of any 'hot' (P < 3 days) companions more massive than 8 MJup, and any 'warm' (P < 30 days) companions more massive than 17 MJup, on average. Assuming an edge-on orbit for the edge-on disk system AU Mic, these observations exclude the presence of any hot Jupiters more massive than 1.8 MJup or warm Jupiters more massive than 3.9 MJup.Comment: Accepted for publication in The Astrophysical Journal. 18 pages, 7 figure

Homologous recombination repair intermediates promote efficient de novo telomere addition at DNA double-strand breaks

The healing of broken chromosomes by de novo telomere addition, while a normal developmental process in some organisms, has the potential to cause extensive loss of heterozygosity, genetic disease, or cell death. However, it is unclear how de novo telomere addition (dnTA) is regulated at DNA double-strand breaks (DSBs). Here, using a non-essential minichromosome in fission yeast, we identify roles for the HR factors Rqh1 helicase, in concert with Rad55, in suppressing dnTA at or near a DSB. We find the frequency of dnTA in rqh1Δ rad55Δ cells is reduced following loss of Exo1, Swi5 or Rad51. Strikingly, in the absence of the distal homologous chromosome arm dnTA is further increased, with nearly half of the breaks being healed in rqh1Δ rad55Δ or rqh1Δ exo1Δ cells. These findings provide new insights into the genetic context of highly efficient dnTA within HR intermediates, and how such events are normally suppressed to maintain genome stabilit

Public Humanities and Publication: A Working Paper

This paper explores the challenges associated with the publication of public and publicly engaged humanities scholarship. It is the product of a working group convened in February 2020 by Routledge, Taylor & Francis and the National Humanities Alliance to identify and discuss model practices for publishing on public and publicly engaged humanities work in higher education. Its central thesis is this: the spread of publicly engaged work via academic publication holds the potential to benefit all, across communities and humanities disciplines. Public humanities work encompasses humanities research, teaching, preservation and programming, conducted for diverse individuals and communities. Publicly engaged humanities work, meanwhile, encompasses humanities research, teaching, preservation and programming, conducted with and for diverse individuals and communities. The innovative nature of this work, driven, often, by co-equal partnership with community members and institutions, broadens the horizons and inclusivity of humanities knowledge. It also, however, creates certain challenges that make publication both more complex and more important