3,500 research outputs found

    The effects of label design characteristics on perceptions of genetically modified food

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    Objective. To explore the effects on perceptions of labelling food for genetically modified content. Background: there is increasing public pressure for the compulsory labelling of genetically modified food content on all food products, and yet little is known about how the design and content of such food labels will influence product perceptions. The current research draws upon warning label research - a field in which the effect of label design manipulations on perceptions of, and responses to, potential or perceived risks is well documented. Method. Two experiments are reported that investigate how label design features influence the perception of genetically modified foods. The effects of label colour (red, blue and green), wording style (definitive vs. probabilistic and explicit vs. non-explicit) and information source (government agency, consumer group and manufacturer) on hazard perceptions and purchase intentions were measured. Results. Hazard perceptions and purchase intentions were both influenced by label design characteristics in predictable ways. Any reference to genetic modification, even if the label is stating that the product is free of genetically modified ingredients, increased hazard perception, and decreased purchase intentions, relative to a no-label condition. Conclusion. Label design effects generalise from warning label research to influence the perception of genetically modified foods in predictable ways. Application. The design of genetically modified food labels. © 2012 Copyright Taylor and Francis Group, LLC

    Attachment, attraction and communication in real and virtual worlds: a study of massively multiplayer online gamers

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    Potential differences between relationships formed in online versus offline venues were explored using an online survey of massively multiplayer online gamers. Participants (N=1654) provided information about two or more relationships (kin, friends, and romantic relationships), indicating whether these had originated in online or offline venues. Attachment, attraction and communication were assessed for each relationship. Relationship security was predicted by attraction, but the effects of venue were limited to avoidance towards online romantic relationships. Personality, gaming motivation, age and sex all made negligible contributions to relationship security. Limitations, including the correlational nature of the data and the high proportion of male participants, as well as suggestions for how relationship research might proceed in an increasingly online world, are discussed

    Tumour-specific arginine vasopressin promoter activation in small-cell lung cancer

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    Small-cell lung cancer (SCLC) can produce numerous mitogenic neuropeptides, which are not found in normal respiratory epithelium. Arginine vasopressin is detected in up to two-thirds of SCLC tumours whereas normal physiological expression is essentially restricted to the hypothalamus. This presents the opportunity to identify elements of the gene promoter which could be exploited for SCLC-specific targeting. A series of human vasopressin 5′ promoter fragments (1048 bp, 468 bp and 199 bp) were isolated and cloned upstream of a reporter gene. These were transfected into a panel of ten cell lines, including SCLC with high or low endogenous vasopressin transcription, non-SCLC and bronchial epithelium. All these fragments directed reporter gene expression in the five SCLC cell lines, but had negligible activity in the control lines. The level of reporter gene expression reflected the level of endogenous vasopressin production, with up to 4.9-fold (s.d. 0.34) higher activity than an SV40 promoter. The elements required for this strong, restricted, SCLC-specific promoter activity are contained within the 199-bp fragment. Further analysis of this region indicated involvement of E-box transcription factor binding sites, although tumour-specificity was retained by a 65-bp minimal promoter fragment. These data show that a short region of the vasopressin promoter will drive strong expression in SCLC in vitro and raise the possibility of targeting gene therapy to these tumours

    Real feelings for virtual people: emotional attachments and interpersonal attraction in video games

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    Factors which may affect how people become attracted to virtual characters were explored in an online survey of players of a recent video role-playing game. Seventy-four participants (33 male) completed a series of questionnaires assessing their personality, motivations for game play, and feelings towards the ten non-player characters (NPCs) with whom they had potentially experienced extensive interactions within the game world. Results suggest that people form real and authentic emotional attachments to virtual characters, and that these arise from a complex blend of the players’ personality and motivation, and the virtual characters’ levels of physical attraction, friendliness (or hostility) and general usefulness within the game context. Implications of these findings, and suggestions for future research, are discussed

    Fatigue failure of regenerator screens in a high frequency Stirling engine

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    Failure of Stirling Space Power Demonstrator Engine (SPDE) regenerator screens was investigated. After several hours of operation the SPDE was shut down for inspection and on removing the regenerator screens, debris of unknown origin was discovered along with considerable cracking of the screens in localized areas. Metallurgical analysis of the debris determined it to be cracked-off-deformed pieces of the 41 micron thickness Type 304 stainless steel wire screen. Scanning electron microscopy of the cracked screens revealed failures occurring at wire crossovers and fatigue striations on the fracture surface of the wires. Thus, the screen failure can be characterized as a fatigue failure of the wires. The crossovers were determined to contain a 30 percent reduction in wire thickness and a highly worked microstructure occurring from the manufacturing process of the wire screens. Later it was found that reduction in wire thickness occurred because the screen fabricator had subjected it to a light cold-roll process after weaving. Installation of this screen left a clearance in the regenerator allowing the screens to move. The combined effects of the reduction in wire thickness, stress concentration (caused by screen movement), and highly worked microstructure at the wire crossovers led to the fatigue failure of the screens

    Estimating the functional form for the density dependence from life history data

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    Two contrasting approaches to the analysis of population dynamics are currently popular: demographic approaches where the associations between demographic rates and statistics summarizing the population dynamics are identified; and time series approaches where the associations between population dynamics, population density, and environmental covariates are investigated. In this paper, we develop an approach to combine these methods and apply it to detailed data from Soay sheep (Ovis aries). We examine how density dependence and climate contribute to fluctuations in population size via age- and sex-specific demographic rates, and how fluctuations in demographic structure influence population dynamics. Density dependence contributes most, followed by climatic variation, age structure fluctuations and interactions between density and climate. We then simplify the density-dependent, stochastic, age-structured demographic model and derive a new phenomenological time series which captures the dynamics better than previously selected functions. The simple method we develop has potential to provide substantial insight into the relative contributions of population and individual-level processes to the dynamics of populations in stochastic environments

    Sub-millimeter images of a dusty Kuiper belt around eta Corvi

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    We present sub-millimeter and mid-infrared images of the circumstellar disk around the nearby F2V star eta Corvi. The disk is resolved at 850um with a size of ~100AU. At 450um the emission is found to be extended at all position angles, with significant elongation along a position angle of 130+-10deg; at the highest resolution (9.3") this emission is resolved into two peaks which are to within the uncertainties offset symmetrically from the star at 100AU projected separation. Modeling the appearance of emission from a narrow ring in the sub-mm images shows the observed structure cannot be caused by an edge-on or face-on axisymmetric ring; the observations are consistent with a ring of radius 150+-20AU seen at 45+-25deg inclination. More face-on orientations are possible if the dust distribution includes two clumps similar to Vega; we show how such a clumpy structure could arise from the migration over 25Myr of a Neptune mass planet from 80-105AU. The inner 100AU of the system appears relatively empty of sub-mm emitting dust, indicating that this region may have been cleared by the formation of planets, but the disk emission spectrum shows that IRAS detected an additional hot component with a characteristic temperature of 370+-60K (implying a distance of 1-2AU). At 11.9um we found the emission to be unresolved with no background sources which could be contaminating the fluxes measured by IRAS. The age of this star is estimated to be ~1Gyr. It is very unusual for such an old main sequence star to exhibit significant mid-IR emission. The proximity of this source makes it a perfect candidate for further study from optical to mm wavelengths to determine the distribution of its dust.Comment: 22 pages, 4 figures. Scheduled for publication in ApJ 10 February 2005 issu

    Measuring molecular abundances in comet C/2014 Q2 (Lovejoy) using the APEX telescope

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    Comet composition provides critical information on the chemical and physical processes that took place during the formation of the Solar system. We report here on millimetre spectroscopic observations of the long-period bright comet C/2014 Q2 (Lovejoy) using the Atacama Pathfinder Experiment (APEX) band 1 receiver between 2015 January UT 16.948 to 18.120, when the comet was at heliocentric distance of 1.30 AU and geocentric distance of 0.53 AU. Bright comets allow for sensitive observations of gaseous volatiles that sublimate in their coma. These observations allowed us to detect HCN, CH3OH (multiple transitions), H2CO and CO, and to measure precise molecular production rates. Additionally, sensitive upper limits were derived on the complex molecules acetaldehyde (CH3CHO) and formamide (NH2CHO) based on the average of the strongest lines in the targeted spectral range to improve the signal-to-noise ratio. Gas production rates are derived using a non-LTE molecular excitation calculation involving collisions with H2O and radiative pumping that becomes important in the outer coma due to solar radiation. We find a depletion of CO in C/2014 Q2 (Lovejoy) with a production rate relative to water of 2 per cent, and relatively low abundances of Q(HCN)/Q(H2O), 0.1 per cent, and Q(H2CO)/Q(H2O), 0.2 per cent. In contrast the CH3OH relative abundance Q(CH3OH)/Q(H2O), 2.2 per cent, is close to the mean value observed in other comets. The measured production rates are consistent with values derived for this object from other facilities at similar wavelengths taking into account the difference in the fields of view. Based on the observed mixing ratios of organic molecules in four bright comets including C/2014 Q2, we find some support for atom addition reactions on cold dust being the origin of some of the molecules.Comment: 10 pages, 7 figures, to be published in MNRA

    Energy dependence on fractional charge for strongly interacting subsystems

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    The energies of a pair of strongly-interacting subsystems with arbitrary noninteger charges are examined from closed and open system perspectives. An ensemble representation of the charge dependence is derived, valid at all interaction strengths. Transforming from resonance-state ionicity to ensemble charge dependence imposes physical constraints on the occupation numbers in the strong-interaction limit. For open systems, the chemical potential is evaluated using microscopic and thermodynamic models, leading to a novel correlation between ground-state charge and an electronic temperature.Comment: 4 pages, 3 figs.; as accepted (Phys. Rev. Lett.

    Deciphering histone 2A deubiquitination

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    The discovery of three different enzymes that deubiquitinate histone 2A
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