The simulator sickness questionnaire, and the erroneous zero baseline assumption

Cybersickness assessment is predominantly conducted via the Simulator Sickness Questionnaire (SSQ). Literature has highlighted that assumptions which are made concerning baseline assessment may be incorrect, especially the assumption that healthy participants enter with no or minimal associated symptoms. An online survey study was conducted to explore further this assumption amongst a general population sample (N = 93). Results for this study suggest that the current baseline assumption may be inherently incorrect

Infrared Behaviour of Propagators and Vertices

We elucidate constraints imposed by confinement and dynamical chiral symmetry breaking on the infrared behaviour of the dressed-quark and -gluon propagators, and dressed-quark-gluon vertex. In covariant gauges the dressing of the gluon propagator is completely specified by P(k^2):= 1/[1+Pi(k^2)], where Pi(k^2) is the vacuum polarisation. In the absence of particle-like singularities in the dressed-quark-gluon vertex, extant proposals for the dressed-gluon propagator that manifest P(k^2=0)=0 and Max[P(k^2)]~10 neither confine quarks nor break chiral symmetry dynamically. This class includes all existing estimates of P(k^2) via numerical simulations.Comment: 10 pages, 2 figure

Remotely sensed dune celerity and sand flux measurements of the world's fastest barchans (Bodele, Chad)

Quantifying sand flux with field measurements is an expensive and time-consuming process. We here present an alternative approach using the COSI-Corr software package for Earth surface deformation detection. Using pairs of ASTER satellite images, we detected dune migration in the Bodélé depression of northern Chad over time intervals of one month to 6.5 years. The displacement map can be used to automatically distinguish dunes from interdunes, which is a crucial step towards calculating sand flux. We interpolated a surface between the interdune areas and subtracted it from a digital elevation model, thus obtaining dune heights and volumes. Multiplying height with celerity yields a pixel-by-pixel estimate of the sand flux. We applied this method to large diatomite dunes in the Bodélé, confirming that these are some of the world's fastest moving barchans. Plotting dune height against inverse celerity reveals sand flux at the dune crest of >200 m3/m/yr. Average dune sand flux values for the eastern and western Bodélé are 76 and 99 m3/m/yr, respectively. The contribution of the dunes to the total area-averaged sand flux is 24–29 m3/m/yr, which is ∼10% of the saltation flux determined by previously published field measurements

Motion-Conditioned Image Animation for Video Editing

We introduce MoCA, a Motion-Conditioned Image Animation approach for video editing. It leverages a simple decomposition of the video editing problem into image editing followed by motion-conditioned image animation. Furthermore, given the lack of robust evaluation datasets for video editing, we introduce a new benchmark that measures edit capability across a wide variety of tasks, such as object replacement, background changes, style changes, and motion edits. We present a comprehensive human evaluation of the latest video editing methods along with MoCA, on our proposed benchmark. MoCA establishes a new state-of-the-art, demonstrating greater human preference win-rate, and outperforming notable recent approaches including Dreamix (63%), MasaCtrl (75%), and Tune-A-Video (72%), with especially significant improvements for motion edits.Comment: Project page: https://facebookresearch.github.io/MoC

Physical training for loaded marching performance among British Army recruits

Study 1 quantified the validity and repeatability of an automated on-line (ON) gas analysis system during sub-maximal loaded marching (LM) against that of the Douglas Bag (DB) approach. The 95% ratio Limits of Agreement (LoA) revealed the ON system systematically overestimated V02 by -16% (1.16 (x/-i-1.19). The Bland and Altman plots revealed DB repeatability was almost two-fold better than ON (-9% vs. -15%), thus the DB approach should be used subsequently to measure human expired gases. Study 2 investigated the difference between an LM maximal oxygen uptake protocol (LMp) versus a standard running protocol (Rp). The LMp V02max was lower than Rp (48.6 ± 4.3 ml·kg-I·min-I vs. 51.3 ± 4.0 ml·kg-I·min-I, P=0.001). Thus, the quantification of sub-maximal LM exercise intensity will be underestimated by -5% if derived from a running tiOzmax protocol. Study 3 investigated the repeatability of accepted and potential determinants of Loaded Marching Performance (LMP). The LoA revealed the repeatability of Loaded Marching Economy (LME) (0.98 (x/-i-1.09», V02max (1.01 (xl-i-1.07», upper body dynamic strength (1.01 (x/-i- 1.11», and anthropometric measures (1.00 (x/-i- 1.02» to (1.00 (x/-i- 1.07» was reasonable, but dynamic leg strength (1.06 (x/-i-1.14» and isometric strength (1.00 (x/-i-1.12» to (0.99 (x/-i-1.l6» were large. Study 4 established the determinants of 2.4 km LMP from a test battery performed at the beginning of British Army infantry training. The best mathematical model of LMP included the independent variables of LME (r=0.65), 2.4 km run time (r=0.42), and peak static lift strength (r=0.48). This explained 65% of the variation in LMP, and had a prediction error of ± 51 s. Mathematically, LME and 2.4 km run time exerted the greatest influence on LMP, whereas the influence of static lift strength on LMP was small. Study 5 investigated the physical and physiological responses of the established determinants of LMP during 24 weeks of British Army infantry training. Loaded marching performance improved 7.0% (900 s to 837 s, P=0.001), LME 9.6% (2.28 I·min- I to 2.06 I·min- I , P ...EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Investigation of gene–environment interactions in relation to tic severit

Tourette syndrome (TS) is a neuropsychiatric disorder with involvement of genetic and environmental factors. We investi gated genetic loci previously implicated in Tourette syndrome and associated disorders in interaction with pre- and perinatal adversity in relation to tic severity using a case-only (N=518) design. We assessed 98 single-nucleotide polymorphisms (SNPs) selected from (I) top SNPs from genome-wide association studies (GWASs) of TS; (II) top SNPs from GWASs of obsessive–compulsive disorder (OCD), attention-defcit/hyperactivity disorder (ADHD), and autism spectrum disorder (ASD); (III) SNPs previously implicated in candidate-gene studies of TS; (IV) SNPs previously implicated in OCD or ASD; and (V) tagging SNPs in neurotransmitter-related candidate genes. Linear regression models were used to examine the main efects of the SNPs on tic severity, and the interaction efect of these SNPs with a cumulative pre- and perinatal adversity score. Replication was sought for SNPs that met the threshold of signifcance (after correcting for multiple testing) in a rep lication sample (N=678). One SNP (rs7123010), previously implicated in a TS meta-analysis, was signifcantly related to higher tic severity. We found a gene–environment interaction for rs6539267, another top TS GWAS SNP. These fndings were not independently replicated. Our study highlights the future potential of TS GWAS top hits in gene–environment studies

Optimal level of groundwater charge to promote rainwater usage for irrigation in rural Beijing

Abstract: Since groundwater is diminishing rapidly in rural Beijing, rainwater harvesting for irrigation is being promoted. As the cost of pumping up groundwater is low, farmers have few incentives to use rainwater. To promote the consumption of rainwater, the Beijing Water Authority may in the future raise the cost of using groundwater by introducing a charge. Higher cost of groundwater will increase the consumption of rainwater, but can have a negative impact on farmers’ incomes. This paper aims to study how to increase rainwater consumption without discouraging farming. The relation between the cost of groundwater and the consumption of rainwater has been studied by analyzing the elasticity of groundwater demand graphically. If the cost of groundwater is lower than the elasticity threshold, farmers lack incentives to use rainwater. If the cost of groundwater is higher than the threshold, rainwater consumption increases. The elasticity threshold of groundwater can move down following a change in the characteristics of rainwater harvesting systems. With linear programming analysis it has been found that increasing subsidies and enlarging the size of rainwater harvesting systems decreases the elasticity threshold of groundwater. This results in a proposal for a realistic charge for groundwater, affecting the consumption of rainwater but also taking into account the income of the farmers

Light from the Darkness: Detecting Ultra-diffuse Galaxies in the Perseus Cluster through Over-densities of Globular Clusters with a Log-Gaussian Cox Process

We introduce a new method for detecting ultra-diffuse galaxies by searching for over-densities in intergalactic globular cluster populations. Our approach is based on an application of the log-Gaussian Cox process, which is a commonly used model in the spatial statistics literature but rarely used in astronomy. This method is applied to the globular cluster data obtained from the PIPER survey, a Hubble Space Telescope imaging program targeting the Perseus cluster. We successfully detect all confirmed ultra-diffuse galaxies with known globular cluster populations in the survey. We also identify a potential galaxy that has no detected diffuse stellar content. Preliminary analysis shows that it is unlikely to be merely an accidental clump of globular clusters or other objects. If confirmed, this system would be the first of its kind. Simulations are used to assess how the physical parameters of the globular cluster systems within ultra-diffuse galaxies affect their detectability using our method. We quantify the correlation of the detection probability with the total number of globular clusters in the galaxy and the anticorrelation with increasing half-number radius of the globular cluster system. The Sérsic index of the globular cluster distribution has little impact on detectability

The Rise of Massive Red Galaxies: the color-magnitude and color-stellar mass diagrams for z < ~2 from the MUltiwavelength Survey by Yale-Chile (MUSYC)

We present the color-magnitude and color-stellar mass diagrams for galaxies with z_phot < ~2, based on a K < 22 (AB) catalog of the Extended Chandra Deep Field South (ECDFS) from the MUltiwavelength Survey by Yale-Chile (MUSYC). Our main sample of 7840 galaxies contains 1297 M_* > 10^11 M_Sol galaxies in the range 0.2 < z_phot < 1.8. We show empirically that this catalog is approximately complete for M_* > 10^11 M_Sol galaxies for z_phot < 1.8. For this mass-limited sample, we show that the locus of the red sequence color-stellar mass relation evolves as Del(u-r) ~ (-0.44+/-0.02) z_phot for z_phot ~1.3, however, we are no longer able to reliably distinguish red and blue subpopulations from the observed color distribution; we show that this would require much deeper near infrared data. At 1.5 < z_phot 10^11 M_Sol galaxies is ~50% of the local value, with a red fraction of ~33%. Making a parametric fit to the observed evolution, we find n_tot(z) ~ (1+z_phot)^(-0.52+/-0.12(+/-0.20)). We find stronger evolution in the red fraction: f_red(z) ~ (1+z_phot)^(-1.17+/-0.18(+/-0.21)). Through a series of sensitivity analyses, we show that the most important sources of systematic error are: 1. systematic differences in the analysis of the z~0 and z>>0 samples; 2. systematic effects associated with details of the photometric redshift calculation; and 3. uncertainties in the photometric calibration. With this in mind, we show that our results based on photometric redshifts are consistent with a completely independent analysis which does not require redshift information for individual galaxies. Our results suggest that, at most, 1/5 of local red sequence galaxies with M_* >10^11 M_Sol were already in place at z ~ 2.Comment: Accepted for publication in ApJ. 31 pages in emulateapj format; 18 figues (14 in main text). Additional online data available through http://www.strw.leidenuniv.nl/~ent