Demographic and psychological variables affecting test subject evaluations of ride quality

Ride-quality experiments similar in objectives, design, and procedure were conducted, one using the U.S. Air Force Total In-Flight Simulator and the other using the Langley Passenger Ride Quality Apparatus to provide the motion environments. Large samples (80 or more per experiment) of test subjects were recruited from the Tidewater Virginia area and asked to rate the comfort (on a 7-point scale) of random aircraft motion typical of that encountered during STOL flights. Test subject characteristics of age, sex, and previous flying history (number of previous airplane flights) were studied in a two by three by three factorial design. Correlations were computed between one dependent measure, the subject's mean comfort rating, and various demographic characteristics, attitudinal variables, and the scores on Spielberger's State-Trait Anxiety Inventory. An effect of sex was found in one of the studies. Males made higher (more uncomfortable) ratings of the ride than females. Age and number of previous flights were not significantly related to comfort ratings. No significant interactions between the variables of age, sex, or previous number of flights were observed

L'CO/LFIR Relations with CO Rotational Ladders of Galaxies Across the Herschel SPIRE Archive

We present a catalog of all CO (J=4-3 through J=13-12)), [CI], [NII] lines available from extragalactic spectra from the Herschel SPIRE Fourier Transform Spectrometer (FTS) archive combined with observations of the low-J CO lines from the literature and from the Arizona Radio Observatory. This work examines the relationships between LFIR, L'CO, and LCO/LCO(1-0). We also present a new method for estimating probability distribution functions (PDFs) from marginal signal-to-noise ratio Herschel} FTS spectra, which takes into account the instrumental "ringing" and the resulting highly correlated nature of the spectra. The slopes of log(LFIR) vs. log(L'CO) are linear for all mid- to high-J CO lines and slightly sublinear if restricted to (U)LIRGs. The mid- to high-J CO luminosity relative to CO J=1-0 increases with increasing LFIR, indicating higher excitement of the molecular gas, though these ratios do not exceed ~ 180. For a given bin in LFIR, the luminosities relative to CO J=1-0 remain relatively flat from J=6-5 through J=13-12, across three orders of magnitude of LFIR. A single component theoretical photon-dominated region (PDR) model cannot match these flat SLED shapes, though combinations of PDR models with mechanical heating added qualitatively match the shapes, indicating the need for further comprehensive modeling of the excitation processes of warm molecular gas in nearby galaxies.Comment: 17 pages, 4 figures (including appendix), accepted by ApJ. Full tables will be in VizieR upon publication, email first author for tables in the meantim

Self-Perceptions as Writers of Written Language Learning Disabled Students

This qualitative descriptive study sought to describe the self-perceptions as writers of written language learning disabled students who are able to use the Alpha-Smart Pro personal computer for written language assignments. The participants were two sixth-grade students each with a verified learning disability in the area of written language. The participants were one male and one female. Data were collected over a six week period and included interviews, Q-Sort observations and written work samples. Data analysis occurred during and after the six weeks of data collection. The study discovered, a) the female participant used writing regularly in her life as a means of self-expression, b) both participants perceived themselves to use rewriting/revision when in fact they used editing, c) the female participant perceived herself to use poetry as a way to improve a bad mood. This was unable to be founded since the poetry was not seen by the researcher, and d) the Alpha-Smart was not mentioned by the participants during interviews however, Alpha-Smart use was seen during classroom observations. This study was different than the quantitative research previously completed in the areas of computers and classroom writing and self-perceptions of learning disabled students in that prior research compared learning disabled students to non-learning disabled classmates. The results of the prior studies indicated lower self-perceptions of students with learning disabilities than those students without learning disabilities. The present study did not conduct comparisons but rather aimed to describe self-perceptions as the students saw themselves. The results indicated that despite the fact that the participants writing was below sixth grade level the participants perceived themselves to be good writers. Implications for teachers included several suggestions: (a) provide various writing opportunities, as opposed to just academic writing, to written language learning disabled students; (b) allow learning disabled students to discuss their self-perceptions of their abilities without asking for a comparison of themselves to other non-learning disabled students, doing so will potentially allow the students to positively discuss their own self-perceptions; and (c) teach revision skills in a hands-on repeated practice style so as to ensure the successful application of the skill

Experimental constraints on the uncoupled Galileon model from SNLS3 data and other cosmological probes

The Galileon model is a modified gravity theory that may provide an explanation for the accelerated expansion of the Universe. This model does not suffer from instabilities or ghost problems (normally associated with higher-order derivative theories), restores local General Relativity -- thanks to the Vainshtein screening effect -- and predicts late time acceleration of the expansion. In this paper, we derive a new definition of the Galileon parameters that allows us to avoid having to choose initial conditions for the Galileon field, and then test this model against precise measurements of the cosmological distances and the rate of growth of cosmic structures. We observe a small tension between the constraints set by growth data and those from distances. However, we find that the Galileon model remains consistent with current observations and is still competitive with the \Lambda CDM model, contrary to what was concluded in recent publications.Comment: 19 pages, 15 figures, accepted to Astronomy and Astrophysic

First experimental constraints on the disformally coupled Galileon model

The Galileon model is a modified gravity model that can explain the late-time accelerated expansion of the Universe. In a previous work, we derived experimental constraints on the Galileon model with no explicit coupling to matter and showed that this model agrees with the most recent cosmological data. In the context of braneworld constructions or massive gravity, the Galileon model exhibits a disformal coupling to matter, which we study in this paper. After comparing our constraints on the uncoupled model with recent studies, we extend the analysis framework to the disformally coupled Galileon model and derive the first experimental constraints on that coupling, using precise measurements of cosmological distances and the growth rate of cosmic structures. In the uncoupled case, with updated data, we still observe a low tension between the constraints set by growth data and those from distances. In the disformally coupled Galileon model, we obtain better agreement with data and favour a non-zero disformal coupling to matter at the $2.5\sigma$ level. This gives an interesting hint of the possible braneworld origin of Galileon theory.Comment: 9 pages, 6 figures, updated versio

Constraining Type Ia Supernovae progenitors from three years of SNLS data

While it is generally accepted that Type Ia supernovae are the result of the explosion of a carbon-oxygen White Dwarf accreting mass in a binary system, the details of their genesis still elude us, and the nature of the binary companion is uncertain. Kasen (2010) points out that the presence of a non-degenerate companion in the progenitor system could leave an observable trace: a flux excess in the early rise portion of the lightcurve caused by the ejecta impact with the companion itself. This excess would be observable only under favorable viewing angles, and its intensity depends on the nature of the companion. We searched for the signature of a non-degenerate companion in three years of Supernova Legacy Survey data by generating synthetic lightcurves accounting for the effects of shocking and comparing true and synthetic time series with Kolmogorov-Smirnov tests. Our most constraining result comes from noting that the shocking effect is more prominent in rest-frame B than V band: we rule out a contribution from white dwarf-red giant binary systems to Type Ia supernova explosions greater than 10% at 2 sigma, and than 20% at 3 sigma level.Comment: 14 pages, 15 figures, resubmitted to ApJ, figure 15 modifie

Experimenting with online governance

To solve the problems they face, online communities adopt comprehensive governance methods including committees, boards, juries, and even more complex institutional logics. Helping these kinds of communities succeed will require categorizing best practices and creating toolboxes that fit the needs of specific communities. Beyond such applied uses, there is also a potential for an institutional logic itself to evolve, taking advantage of feedback provided by the fast pace and large ecosystem of online communication. Here, we outline an experimental strategy aiming at guiding and facilitating such an evolution. We first review the advantages of studying collective action using recent technologies for efficiently orchestrating massive online experiments. Research in this vein includes attempts to understand how behavior spreads, how cooperation evolves, and how the wisdom of the crowd can be improved. We then present the potential usefulness of developing virtual-world experiments with governance for improving the utility of social feedback. Such experiments can be used for improving community rating systems and monitoring (dashboard) systems. Finally, we present a framework for constructing large-scale experiments entirely in virtual worlds, aimed at capturing the complexity of governance dynamics, to empirically test outcomes of manipulating institutional logic.Received: 14 November 2020; Accepted: 23 March 2021; Published: 26 April 2021

Real-time Analysis and Selection Biases in the Supernova Legacy Survey

The Supernova Legacy Survey (SNLS) has produced a high-quality, homogeneous sample of Type Ia supernovae (SNe Ia) out to redshifts greater than z=1. In its first four years of full operation (to June 2007), the SNLS discovered more than 3000 transient candidates, 373 of which have been confirmed spectroscopically as SNe Ia. Use of these SNe Ia in precision cosmology critically depends on an analysis of the observational biases incurred in the SNLS survey due to the incomplete sampling of the underlying SN Ia population. This paper describes our real-time supernova detection and analysis procedures, and uses detailed Monte Carlo simulations to examine the effects of Malmquist bias and spectroscopic sampling. Such sampling effects are found to become apparent at z~0.6, with a significant shift in the average magnitude of the spectroscopically confirmed SN Ia sample towards brighter values for z>0.75. We describe our approach to correct for these selection biases in our three-year SNLS cosmological analysis (SNLS3), and present a breakdown of the systematic uncertainties involved.Comment: Accepted for publication in A

The Roles of Dietary Nitrate in Bone and the Gut in an Ovarian Hormone-deficient Rodent Model

Osteoporosis is a common metabolic bone disease, affecting a third of women and a fifth of men over age 65. In the US, annual health care costs associated with osteoporosis are estimated to be over $20 billion. Osteoporosis is associated with increased fracture risk, which has been demonstrated to predict mortality rates and nursing home admittance. Altered bone remodeling, defined by excessive bone resorption and/or impaired bone formation, is a major risk factor for osteoporotic fracture. In menopause-induced ovarian hormone deficiency, bone resorption exceeds formation. Menopause-induced bone resorption is associated with a reduced bone mineral density (BMD), and there is a relationship between low BMD and increased fracture risk. Given the importance of bone remodeling and fracture risk, there have been significant efforts to understand the ability of dietary components to slow bone loss. Some observational studies report that fruit and vegetable consumption is associated with an increase in bone mineral content (BMC) and BMD. Dietary nitrates, present in high concentrations in leafy green vegetables, may serve as a dietary component that supports bone health. Vegetable intake accounts for ~80% of dietary nitrate consumption in the typical human diet. Dietary nitrates can be reduced to nitric oxide (NO) via non-enzymatic reduction by lingual bacteria and a variety of mammalian reductases through the nitrate-nitrite-NO pathway. There is evidence suggesting that strategies to increase NO bioavailability using organic nitrates (i.e., nitroglycerin) as an NO donor may decrease bone turnover and loss in ovariectomized (OVX) animals, which are animals that have had their ovaries surgically removed to induce a postmenopausal-like state, defined by diminished ovarian production of female hormones, particularly estrogen and progesterone. Some follow up trials in postmenopausal women have demonstrated similar results. Since non-enzymatic reduction of dietary nitrate can account for up to 50% of NO production, this provides a biologically plausible link between dietary nitrate and bone health and suggests that dietary nitrate, as an alternate NO donor, may offer efficacious means of decreasing bone loss in postmenopausal women. Here, using an in vivo approach, we examined the dose-response relationship between dietary nitrates and bone density, microarchitecture, and turnover in OVX rats. We show that dietary nitrates do not improve bone density, microarchitecture, or turnover. Further, dietary nitrate had no beneficial effect on mineral apposition rate, bone formation rate, or bone volume/tissue volume in OVX rats. Our novel findings demonstrate dietary nitrate does not slow ovx-induced bone loss. This knowledge clarified the relationship between a dietary compound found in large quantities in leafy greens and bone loss in an OVX model. As an exploratory component of this study, we used 16S rRNA gene sequencing to profile the composition of fecal microbiota associated with sham surgical controls, OVX, and nitrate-treated groups to evaluate the ability of OVX or dietary nitrate to modulate the gut microbiome in OVX mammals. While dietary nitrate did not alter the gut microbiome in the context of OVX, we did observe gut microbiome changes in structure and composition associated with OVX status and identified specific phylotypes whose abundance stratify sham and OVX rats, including Proteobacteria, Firmicutes, and Bacteroidetes. These results add to the growing body of evidence that there is an association between the gut microbiome and sex steroid deficiency. Our use of the OVX model also provided an important added opportunity to further our understanding of the tissue effects of sex steroid deficiency observed in menopause. While both progesterone and estrogen influence metabolism, most attention has been given to the effects of ovarian hormone deficiency. Complex interactions between estrogen and host metabolism suggest that tissues in addition to serum and urine must be examined to clarify the mechanistic underpinnings of ovarian hormone deficiency and associated disease risk. Insufficient data are available from tissue-based studies using NMR-based platforms in estrogen-deficient models. Metabolomic studies in OVX rats, a model for osteoporosis, and postmenopausal women have demonstrated major metabolic shifts in serum, plasma, and urine as a result of ovarian hormone deficiency. To our knowledge, metabolomics has not been used for investigating the metabolic phenotype observed in the postmenopausal colon. Metabolomic studies of ovarian hormone deficiency is limited to bone, adipose, skeletal muscle, serum, plasma, and urine. Further, while it is established that ovarian hormone deficiency causes metabolic dysregulation, and the gut is associated with metabolic diseases and bone metabolism, there is also limited information available on the effects of estrogen loss on both gut tissue and gut microbiota. In light of this and our observed gut microbiome differences in OVX rats, we evaluated the effects of OVX on the colon using a metabolomics approach. We found the OVX colon is characterized by elevated levels of antioxidants, such as taurine and hypotaurine, and osmolytes, such as glycerophospholine, glycine, and glutamate. These novel findings suggest alterations to the colonic transsulfuration and methylation pathways, and they are suggestive of hyperosmotic and oxidative stress in the OVX colon. Previous work has associated hyperosmotic and oxidative stress with inflammation and intestinal permeability. These processes may also be present in the OVX colon; however, we did not quantify either inflammation or intestinal permeability in the current body of work. This dissertation takes advantage of a postmenopausal osteoporosis animal model and integrative techniques, such as osteologic, immunological, metabonomic, microbiomic and bioinformatic methods, to evaluate different metrics of osteoporosis, including physiological determinants influencing the rate of bone loss and gut-associated changes in ovarian hormone deficiency. The central findings of this dissertation show that dietary nitrate does not slow bone loss in ovarian hormone deficiency-induced rat model of bone loss. Further, dietary nitrate does not appear to influence the gut microbiome in the context of OVX. This is important in furthering our understanding of the relationship between the consumption of this ubiquitous component of fruit and vegetables and bone health. We also demonstrate that OVX is associated with shifts in gut microbiome structure and composition. Finally, we show OVX influences the colon metabolic phenotype, inducing the upregulation of metabolites involved with hyperosmotic and oxidative stress. Since estrogen protects against oxidative stress in many other tissues, we hypothesize that ovarian hormone deficiency promotes oxidative and hyperosmotic stress in the colon, promoting intestinal permeability and elevating the inflammatory response. In response, the colonic transsulfuration and methylation pathways may adapt by upregulating osmolytes and antioxidants. However, the specific causative agents of oxidative stress cannot be derived from our current work. Further investigation of the role these metabolites and processes play in the development of inflammation and metabolic dysregulation will yield insights into the physiological effects of ovarian hormone deficiency in postmenopausal women, allowing for more informed diagnosis and treatment of susceptible individuals