4,406 research outputs found

    Investigating the relationship between substance use and sexual behaviour in young people in Britain: findings from a national probability survey.

    Get PDF
    BACKGROUND: Health risk behaviours are prominent in late adolescence and young adulthood, yet UK population-level research examining the relationship between drug or alcohol use and sexual health and behaviour among young people is scarce, despite public health calls for an integrated approach to health improvement. Our objective was to further our understanding of the scale of and nature of any such relationship, using contemporary data from Britain's third National Survey of Sexual Attitudes and Lifestyles (Natsal-3). METHODS: Analyses of data from Natsal-3, a stratified probability survey of 15 162 men and women (3869 aged 16-24 years), undertaken in 2010-2012, using computer-assisted personal interviewing, were carried out. Logistic regression was used to explore associations between reporting (1) frequent binge drinking (≥weekly), (2) recent drug use (within past 4 weeks) or (3) multiple (both types of) substance use, and key sexual risk behaviours and adverse sexual health outcomes. We then examined the sociodemographic profile, health behaviours and attitudes reported by 'risky' young people, defined as those reporting ≥1 type of substance use plus non-condom use at first sex with ≥1 new partner(s), last year. RESULTS: Men and women reporting frequent binge drinking or recent drug use were more likely to report: unprotected first sex with ≥1 new partner(s), last year; first sex with their last partner after only recently meeting; emergency contraception use (last year) and sexually transmitted infection diagnosis/es (past 5 years). Associations with sexual risk were frequently stronger for those reporting multiple substance use, particularly among men. The profile of 'risky' young people differed from that of other 16-24 years old. CONCLUSIONS: In this nationally representative study, substance use was strongly associated with sexual risk and adverse sexual health outcomes among young people. Qualitative or event-level research is needed to examine the context and motivations behind these associations to inform joined-up interventions to address these inter-related behaviours

    Pathologies in Asymptotically Lifshitz Spacetimes

    Full text link
    There has been significant interest in the last several years in studying possible gravitational duals, known as Lifshitz spacetimes, to anisotropically scaling field theories by adding matter to distort the asymptotics of an AdS spacetime. We point out that putative ground state for the most heavily studied example of such a spacetime, that with a flat spatial section, suffers from a naked singularity and further point out this singularity is not resolvable by any known stringy effect. We review the reasons one might worry that asymptotically Lifshitz spacetimes are unstable and employ the initial data problem to study the stability of such systems. Rather surprisingly this question, and even the initial value problem itself, for these spacetimes turns out to generically not be well-posed. A generic normalizable state will evolve in such a way to violate Lifshitz asymptotics in finite time. Conversely, enforcing the desired asymptotics at all times puts strong restrictions not just on the metric and fields in the asymptotic region but in the deep interior as well. Generically, even perturbations of the matter field of compact support are not compatible with the desired asymptotics.Comment: 36 pages, 1 figure, v2: Enhanced discussion of singularity, including relationship to Gubser's conjecture and singularity in RG flow solution, plus minor clarification

    Ceria Entrapped Palladium Novel Composites for Hydrogen Oxidation Reaction in Alkaline Medium

    Get PDF
    A new heterogeneous catalyst for hydrogen oxidation reaction (HOR), metallic palladium within which nanoparticles of ceria are entrapped, CeO2@Pd, is described. Its preparation is based on a new materials methodology of molecular doping of metals. The metallic matrix, which encages the nanoparticles, is prepared in foam architecture, to ensure easy molecular diffusion. Characterization of the structural properties of the CeO2@Pd composite using SEM, STEM, TEM, XRD, EXAFS and nitrogen adsorption reveals its morphological architecture, which leads to improved catalytic activity. In-situ electrochemical and H2 temperature-programmed reduction (H2-TPR) spectra provide direct experimental evidence of the weakening of Pd‒H bond in the CeO2@Pd composites, relative to pure (undoped) Pd catalysts. Gas diffusion electrodes based on the entrapped CeO2@Pd catalysts demonstrated one order of magnitude higher activity than pure Pd analog in the HOR reaction in an alkaline medium

    Behavioural syndrome in a solitary predator is independent of body size and growth rate.

    Get PDF
    Models explaining behavioural syndromes often focus on state-dependency, linking behavioural variation to individual differences in other phenotypic features. Empirical studies are, however, rare. Here, we tested for a size and growth-dependent stable behavioural syndrome in the juvenile-stages of a solitary apex predator (pike, Esox lucius), shown as repeatable foraging behaviour across risk. Pike swimming activity, latency to prey attack, number of successful and unsuccessful prey attacks was measured during the presence/absence of visual contact with a competitor or predator. Foraging behaviour across risks was considered an appropriate indicator of boldness in this solitary predator where a trade-off between foraging behaviour and threat avoidance has been reported. Support was found for a behavioural syndrome, where the rank order differences in the foraging behaviour between individuals were maintained across time and risk situation. However, individual behaviour was independent of body size and growth in conditions of high food availability, showing no evidence to support the state-dependent personality hypothesis. The importance of a combination of spatial and temporal environmental variation for generating growth differences is highlighted

    Congenital cystic eye with multiple dermal appendages: a case report

    Get PDF
    BACKGROUND: A partial or complete failure in the involution of the primary optic vesicle resulting in the formation of a cyst is an extremely rare anomaly known as congenital cystic eye. The primary optic vesicle is formed but instead of the anterior part of the vesicle involuting to lie in apposition with the posterior part, a cyst persists at birth and replaces the eye. CASE PRESENTATION: We report a case of congenital cystic eye associated with multiple dermal appendages in a 1-day-old female child. This condition presented at birth as a large orbital mass in the left orbit that bulged forwards and stretched the eyelids. No globe or any other ocular structures were identified in the orbit. Multiple dermal appendages were present in the adjacent part of the face below the left orbit and on the upper part of the neck. CONCLUSIONS: Congenital cystic eye is an extremely rare condition and with only 28 previous cases reported in the literature. We present the second case of congenital cystic eye with multiple dermal appendages of the face and neck

    Ages for exoplanet host stars

    Full text link
    Age is an important characteristic of a planetary system, but also one that is difficult to determine. Assuming that the host star and the planets are formed at the same time, the challenge is to determine the stellar age. Asteroseismology provides precise age determination, but in many cases the required detailed pulsation observations are not available. Here we concentrate on other techniques, which may have broader applicability but also serious limitations. Further development of this area requires improvements in our understanding of the evolution of stars and their age-dependent characteristics, combined with observations that allow reliable calibration of the various techniques.Comment: To appear in "Handbook of Exoplanets", eds. Deeg, H.J. & Belmonte, J.A, Springer (2018

    Cultural robotics : The culture of robotics and robotics in culture

    Get PDF
    Copyright 2013 Samani et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedIn this paper, we have investigated the concept of "Cultural Robotics" with regard to the evolution o social into cultural robots in the 21st Century. By defining the concept of culture, the potential development of culture between humans and robots is explored. Based on the cultural values of the robotics developers, and the learning ability of current robots, cultural attributes in this regard are in the process of being formed, which would define the new concept of cultural robotics. According to the importance of the embodiment of robots in the sense of presence, the influence of robots in communication culture is anticipated. The sustainability of robotics culture based on diversity for cultural communities for various acceptance modalities is explored in order to anticipate the creation of different attributes of culture between robot and humans in the futurePeer reviewe

    On the Perturbative Stability of Quantum Field Theories in de Sitter Space

    Full text link
    We use a field theoretic generalization of the Wigner-Weisskopf method to study the stability of the Bunch-Davies vacuum state for a massless, conformally coupled interacting test field in de Sitter space. We find that in λϕ4\lambda \phi^4 theory the vacuum does {\em not} decay, while in non-conformally invariant models, the vacuum decays as a consequence of a vacuum wave function renormalization that depends \emph{singularly} on (conformal) time and is proportional to the spatial volume. In a particular regularization scheme the vacuum wave function renormalization is the same as in Minkowski spacetime, but in terms of the \emph{physical volume}, which leads to an interpretation of the decay. A simple example of the impact of vacuum decay upon a non-gaussian correlation is discussed. Single particle excitations also decay into two particle states, leading to particle production that hastens the exiting of modes from the de Sitter horizon resulting in the production of \emph{entangled superhorizon pairs} with a population consistent with unitary evolution. We find a non-perturbative, self-consistent "screening" mechanism that shuts off vacuum decay asymptotically, leading to a stationary vacuum state in a manner not unlike the approach to a fixed point in the space of states.Comment: 36 pages, 4 figures. Version to appear in JHEP, more explanation

    Expertise differences in anticipatory judgements during a temporally and spatially occluded dynamic task

    Get PDF
    There is contradictory evidence surrounding the role of critical cues in the successful anticipation of penalty kick outcome. In the current study, skilled and less-skilled soccer goalkeepers were required to anticipate spatially (full body; hip region) and temporally (–160 ms, –80 ms before, foot–ball contact) occluded penalty kicks. The skilled group outperformed the less-skilled group in all conditions. Both groups performed better in the full body, compared to hip region condition. Later temporal occlusion conditions were associated with increased performance in the correct response and correct side analysis, but not for correct height. These data suggest that there is enough postural information from the hip region for skilled goalkeepers to make highly accurate predictions of penalty kick direction, however, other regions are needed in order to make predictions of height. These data demonstrate the evolution of cues over time and have implications for anticipation training

    Deceptive body movements reverse spatial cueing in soccer

    Get PDF
    This article has been made available through the Brunel Open Access Publishing Fund.The purpose of the experiments was to analyse the spatial cueing effects of the movements of soccer players executing normal and deceptive (step-over) turns with the ball. Stimuli comprised normal resolution or point-light video clips of soccer players dribbling a football towards the observer then turning right or left with the ball. Clips were curtailed before or on the turn (-160, -80, 0 or +80 ms) to examine the time course of direction prediction and spatial cueing effects. Participants were divided into higher-skilled (HS) and lower-skilled (LS) groups according to soccer experience. In experiment 1, accuracy on full video clips was higher than on point-light but results followed the same overall pattern. Both HS and LS groups correctly identified direction on normal moves at all occlusion levels. For deceptive moves, LS participants were significantly worse than chance and HS participants were somewhat more accurate but nevertheless substantially impaired. In experiment 2, point-light clips were used to cue a lateral target. HS and LS groups showed faster reaction times to targets that were congruent with the direction of normal turns, and to targets incongruent with the direction of deceptive turns. The reversed cueing by deceptive moves coincided with earlier kinematic events than cueing by normal moves. It is concluded that the body kinematics of soccer players generate spatial cueing effects when viewed from an opponent's perspective. This could create a reaction time advantage when anticipating the direction of a normal move. A deceptive move is designed to turn this cueing advantage into a disadvantage. Acting on the basis of advance information, the presence of deceptive moves primes responses in the wrong direction, which may be only partly mitigated by delaying a response until veridical cues emerge
    corecore