605 research outputs found
Coordination Matters : Interpersonal Synchrony Influences Collaborative Problem-Solving
The authors thank Martha von Werthern and Caitlin Taylor for their assistance with data collection, Cathy Macpherson for her assistance with the preparation of the manuscript, and Mike Richardson, Alex Paxton, and Rick Dale for providing MATLAB code to assist with data analysis. The research was funded by the British Academy (SG131613).Peer reviewedPublisher PD
Comparison of scanning Kelvin probe with SEM/EPMA techniques for fingermark recovery from metallic surfaces
Practical application of AAPM Report 270 in display quality assurance: A report of Task Group 270
Published in January 2019, AAPM Report 270 provides an update to the recommendations of the AAPM\u27s TG18 report. Report 270 provides new definitions of display types, updated testing patterns, and revised performance standards for the modern, flat-panel displays used as part of medical image acquisition and review. The focus of the AAPM report is on consistent image quality and appearance, and how to establish a quality assurance program to achieve those two goals. This work highlights some of the key takeaways of AAPM Report 270 and makes comparisons with existing recommendations from other references. It also provides guidance for establishing a display quality assurance program for different-sized institutions. Finally, it describes future challenges for display quality assurance and what work remains
Hubbard models and state preparation in an optical Lieb lattice
Inspired by the growing interest in probing many-body phases in novel two-dimensional lattice geometries we investigate the properties of cold atoms as they could be observed in an optical Lieb lattice. We begin by computing Wannier functions localised at individual sites for a realistic experimental setup, and determining coefficients for a Hubbard-like model. Based on this, we show how experiments could probe the robustness of edge states in a Lieb lattice with diagonal boundary conditions to the effects of interactions and realise strongly correlated many-body phases in this geometry. We then generalise this to interacting particles in a half-filled 1D Lieb ladder, where excitations are dominated by flat band states. We show that for strong attractive interactions, pair correlations are enhanced even when there is strong mixing with the Dirac cone. These findings in 1D raise interesting questions about the phases in the full 2D Lieb lattice which we show can be explored in current experiments
Patient tolerance during outpatient flexible cystoscopy--a prospective, randomized, double-blind study comparing plain lubrication and lidocaine gel.
In utero exposure to cigarette smoke dysregulates human fetal ovarian developmental signalling
STUDY QUESTION How does maternal cigarette smoking disturb development of the human fetal ovary?<p></p>
SUMMARY ANSWER Maternal smoking increases fetal estrogen titres and dysregulates several developmental processes in the fetal ovary.<p></p>
WHAT IS KNOWN ALREADY Exposure to maternal cigarette smoking during gestation reduces human fetal ovarian cell numbers, germ cell proliferation and subsequent adult fecundity.<p></p>
STUDY DESIGN, SIZE, DURATION The effects of maternal cigarette smoking on the second trimester human fetal ovary, fetal endocrine signalling and fetal chemical burden were studied. A total of 105 fetuses were studied, 56 from mothers who smoked during pregnancy and 49 from those who did not.<p></p>
PARTICIPANTS/MATERIALS, SETTING METHODS Ovary, liver and plasma samples were collected from electively terminated, normally progressing, second trimester human fetuses. Circulating fetal hormones, levels of 73 fetal ovarian transcripts, protein localization, density of oocytes/primordial follicles and levels of 16 polycyclic aromatic hydrocarbons (PAHs) in the fetal liver were determined.<p></p>
MAIN RESULTS AND THE ROLE OF CHANCE Circulating fetal estrogen levels were very high and were increased by maternal smoking (ANOVA, P = 0.055–0.004 versus control). Smoke exposure also dysregulated (two-way ANOVA, smoking versus gestation weeks interaction, P = 0.046–0.023) four fetal ovarian genes (cytochrome P450 scc [CYP11A1], NOBOX oogenesis homeobox [NOBOX], activator of apoptosis harakiri [HRK], nuclear receptor subfamily 2, group E, member 1 [NR2E1]), shifted the ovarian Inhibin βA/inhibin α ratio (NHBA/INHA) transcript ratio in favour of activin (ANOVA, P = 0.049 versus control) and reduced the proportion of dominant-negative estrogen receptor 2 (ERβ: ESR2) isoforms in half the exposed fetuses. PAHs, ligands for the aryl hydrocarbon receptor (AHR), were increased nearly 6-fold by maternal smoking (ANOVA, P = 0.011 versus control). A fifth transcript, COUP transcription factor 1 (nuclear receptor subfamily 2, group F, member 1: NR2F1, which contains multiple AHR-binding sites), was both significantly increased (ANOVA, P = 0.026 versus control) and dysregulated by (two-way ANOVA, smoking versus gestation weeks interaction, P = 0.021) maternal smoking. NR2F1 is associated with repression of FSHR expression and smoke-exposed ovaries failed to show the normal increase in FSHR expression during the second trimester. There was a significantly higher number of DEAD (Asp-Glu-Ala-Asp) box polypeptide 4 (DDX4) VASA-positive (ANOVA, P = 0.016 versus control), but not POU domain, class 1, transcription factor 1 (POU5F1) OCT3/4-positive, oocytes in smoke-exposed fetuses and this matched with a significantly higher number of primordial follicles (ANOVA, P = 0.024 versus control).<p></p>
LIMITATIONS, REASONS FOR CAUTION The effects of maternal smoking on establishment of the maximum fetal primordial follicle pool cannot be reliably studied in our population since the process is not completed until 28 weeks of gestation and normal fetuses older than 21 weeks of gestation are not available for study. Our data suggest that some fetal ovaries are affected by smoke exposure while others are not, indicating that additional studies, with larger numbers, may show more significant effects.<p></p>
WIDER IMPLICATIONS OF THE FINDINGS Fetal exposure to chemicals in cigarette smoke is known to lead to reduced fecundity in women. Our study suggests, for the first time, that this occurs via mechanisms involving activation of AHR, disruption of inhibin/activin and estrogen signalling, increased exposure to estrogen and dysregulation of multiple molecular pathways in the exposed human fetal ovary. Our data also suggest that alterations in the ESR2 positive and dominant negative isoforms may be associated with reduced sensitivity of some fetuses to increased estrogens and maternal smoking
Enhanced localization and protection of topological edge states due to geometric frustration
Topologically nontrivial phases are linked to the appearance of localized modes in the boundaries of an open insulator. On the other hand, the existence of geometric frustration gives rise to degenerate localized bulk states. The interplay of these two phenomena may, in principle, result in an enhanced protection/localization of edge states. In this paper, we study a two-dimensional Lieb-based topological insulator with staggered hopping parameters and diagonal open boundary conditions. This system belongs to the C2v class and sustains one-dimensional (1D) boundary modes except at the topological transition point, where the C4v symmetry allows for the existence of localized (0D) corner states. Our analysis reveals that, while a large set of boundary states have a common well-defined topological phase transition, other edge states reflect a topological nontrivial phase for any finite value of the hopping parameters, are completely localized (compact) due to destructive interference, and evolve into corner states when reaching the higher symmetry point. We consider the robustness of these compact edge states with respect to time-dependent perturbations and indicate ways that these states could be prepared and measured in experiments with ultracold atoms
A placebo-controlled study to investigate the effect of Dog Appeasing Pheromone and other environmental and management factors on the reports of disturbance and house soiling during the night in recently adopted puppies (Canis familiaris]
Disturbance and house soiling during the night are common problems faced by the new puppy dog owner. They may result as consequence of a mismatch between the developmental status of the puppy and its new environment and/or separation distress in a typically social animal. The aim of this study was to examine the effect of Dog Appeasing Pheromone (DAP, Ceva Santé Animale) as well as a range of other management and environmental factors that might affect this process. It has been suggested that DAP may help the puppy settle into the new home by continuing the provision of the maternal appeasing pheromone. In order to test this, a double-blind, placebo-controlled trial of DAP was conducted with 60 pedigree puppies, aged between 6 and 10 weeks, as they entered their new home. A few days prior to the puppy's arrival, volunteer owners were supplied with either a verum or placebo plug-in diffuser designed for the slow release of the pheromone analogue over 4 weeks. Owners reported daily on disturbance and house soiling during the previous night over the following 8 weeks from the puppy's first night in the new home. The effect of the treatment together with the gender of the puppy, its maternal environment, the use of a puppy crate, sleeping with other dogs at night and the experience of the owner were included in a general linear model to explain the total number of nights spent disturbing and house soiling. Sleeping with another dog reduced the puppies' tendency to disturb at night to almost zero. Over 70 of puppies sleeping alone disturbed during the first night. The mean total number of nights of disturbance over the 2 months was between five and six nights, mostly in the first week in the home. A significant effect of DAP treatment was found in the case of the gundog breeds only (p = 0.003), gundogs receiving placebo cried for a median of nine nights, those receiving verum cried for a median of three nights. No effect of DAP treatment was observed on the total number of nights that the puppy soiled the house (p > 0.05). However, puppies that were placed in crates during the night (p = 0.004) or had come from domestic maternal environments (p = 0.006) had significantly fewer reports of house soiling over the first 2 months in the new home. © 2006 Elsevier B.V. All rights reserved
Kaleidoscopes of Hofstadter butterflies and Aharonov-Bohm caging from 2n-root topology in decorated square lattices
Square-root topology describes models whose topological properties can be revealed upon squaring the Hamiltonian, which produces their respective parent topological insulators. This concept has recently been generalized to 2n-root topology, characterizing models where n squaring operations must be applied to the Hamiltonian to arrive at the topological source of the model. In this paper, we analyze the Hofstadter regime of quasi-one-dimensional and two-dimensional 2n-root models, the latter of which has the square lattice (SL) (known for the Hofstadter Butterfly) as the source model. We show that upon increasing the root-degree of the model, there appear multiple magnetic flux insensitive flat bands, and we analytically determine corresponding eigenstates. These can be recast as compact localized states (CLSs) occupying a finite region of the lattice. For a finite flux, these CLSs correspond to different harmonics contained within the same Aharonov-Bohm cage. Furthermore, as the root-degree increases, a kaleidoscope of butterflies is seen to appear in the Hofstadter diagram, with each butterfly constituting a topologically equivalent replica of the original one of the SL. As such, the index n, which uniquely identifies the root-degree of the model, can be seen as an additional fractal dimension of the 2n-root model present in its Hofstadter diagram. We discuss how these dynamics could be realized in experiments with ultracold atoms, and measured by Bragg spectroscopy or through observing dynamics of initially localized atoms in a quantum gas microscope
A Bayesian Modelling of Wildfires in Portugal
In the last decade wildfires became a serious problem in Portugal due to
different issues such as climatic characteristics and nature of Portuguese forest. In
order to analyse wildfire data, we employ beta regression for modelling the proportion
of burned forest area, under a Bayesian perspective. Our main goal is to find
out fire risk factors that influence the proportion of area burned and what may make
a forest type susceptible or resistant to fire. Then, we analyse wildfire data in Portugal
during 1990-1994 through Bayesian beta models t
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