33,865 research outputs found

    Using a qualitative approach to explore the human response to vibration in residential environments in the United Kingdom

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    As a growing number of areas in the UK become ever more densely populated, increasing construction work is being undertaken and transportation networks built in order to cope with the growing population. The development of this infrastructure, coupled with the mechanisation of modern life, often results in exposure to various types of vibration from a range of sources such as rail, road traffic and construction activity causing considerable disturbance. The study of vibration effects within residential settings is a developing area of research. Previous research on ambient stressors in residential environments has focused primarily on noise; one of the most prevalent environmental stressors in living environments. Some noise surveys have highlighted vibration as a contributor to noise annoyance while others have explored the combined effects of noise and vibration on human response. Research on vibration is largely a quantitative effort using laboratory experiments or social surveys with associated vibration measurements in order to establish dose-response relationships. However, as the human response to vibration is particularly diverse and complex this paper aims to explore how qualitative methodologies can compliment the quantitative approach to vibration research. People’s experiences, expectations and attitudes vary with regards to vibration, the noise it produces, and the source it derives from. For the pragmatic researcher qualitative methodologies can help unravel some of these issues, providing a further understanding of the complexities of the human response to vibration in residential environments

    Double minimum in the surface stabilized ferroelectric liquid crystal switching response

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    A double minimum has recently been observed in the time–voltage switching response for a smectic C* liquid crystal layer in the surface stabilized geometry (“Ferroelectric Liquid Crystal Device,” K. P. Lymer and J. C. Jones, U.K. Patent No. GB2338797, 17th June 1999). Liquid crystal continuum theory is used to demonstrate that this unusual switching behavior arises if the equilibrium orientation of the molecular director rotates around the smectic cone as a function of distance through one half of the layer only. The double minimum is shown to evolve for large differences between the ε2 and ε1 components of the smectic C biaxial permittivity tensor

    Human response to vibration in residential environments (NANR209), technical report 2: measurement of response

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    Based on a review of the literature and the best practice guidance available, a social survey questionnaire was developed to measure residents’ self-reported annoyance and to provide data suitable for establishing exposure-response relationships between levels of annoyance and levels of vibration. The development of the questionnaire was influenced by a number of previous studies such as: the social survey questionnaire developed for the NANR172 Pilot Study of this research (Defra, 2007); best practice guidelines for the development of socio-acoustic surveys issued by ICBEN and presented in the current International Standard (Fields et al., 2001; ISO/TS 15666:2003); the Nordtest Method (2001) for the development of socio-vibration surveys, and a peer review of the social survey questionnaire by international experts in the field. In order to avoid influencing responses and reasons for participation in the research, the survey was introduced as a survey of neighbourhood satisfaction. The questionnaire design, through the use of sections, enables new sections to be added to the questionnaire so that specific vibration sources can be investigated in more depth. In addressing the ‘response’ component in the ‘exposure-response’ relationship, the questionnaire was designed to yield interval-level measurement data suitable for analysis with vibration measurement data via two response scales: the five-point semantic and the eleven-point numerical scales. This decision was largely founded upon the ability of the two scales to meet the criteria established by ICBEN (Fields et al., 2001) for socio-acoustic survey design. Detailed procedures were documented, following the field trial of the questionnaire, in terms of the role of the interviewer, the recording of information and the transfer of the data to the relevant database for subsequent analysis and to inform the vibration team responsible for the ‘exposure’ component of this research project

    Spatial imaging of Zn and other elements in Huanglongbing-affected grapefruit by synchrotron-based micro X-ray fluorescence investigation

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    Huanglongbing (HLB) is a highly destructive, fast-spreading disease of citrus, causing substantial economic losses to the citrus industry worldwide. Nutrient levels and their cellular distribution patterns in stems and leaves of grapefruit were analysed after graft-inoculation with lemon scions containing 'Candidatus Liberibacter asiaticus' (Las), the heat-tolerant Asian type of the HLB bacterium. After 12 months, affected plants showed typical HLB symptoms and significantly reduced Zn concentrations in leaves. Micro-XRF imaging of Zn and other nutrients showed that preferential localization of Zn to phloem tissues was observed in the stems and leaves collected from healthy grapefruit plants, but was absent from HLB-affected samples. Quantitative analysis by using standard references revealed that Zn concentration in the phloem of veins in healthy leaves was more than 10 times higher than that in HLB-affected leaves. No significant variation was observed in the distribution patterns of other elements such as Ca in stems and leaves of grapefruit plants with or without graft-inoculation of infected lemon scions. These results suggest that reduced phloem transport of Zn is an important factor contributing to HLB-induced Zn deficiency in grapefruit. Our report provides the first in situ, cellular level visualization of elemental variations within the tissues of HLB-affected citrus. © 2014 © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology

    Orbitofrontal cortex volume and brain reward response in obesity.

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    Background/objectivesWhat drives overconsumption of food is poorly understood. Alterations in brain structure and function could contribute to increased food seeking. Recently, brain orbitofrontal cortex (OFC) volume has been implicated in dysregulated eating but little is known how brain structure relates to function.Subjects/methodsWe examined obese (n=18, age=28.7±8.3 years) and healthy control women (n=24, age=27.4±6.3 years) using a multimodal brain imaging approach. We applied magnetic resonance and diffusion tensor imaging to study brain gray and white matter volume as well as white matter (WM) integrity, and tested whether orbitofrontal cortex volume predicts brain reward circuitry activation in a taste reinforcement-learning paradigm that has been associated with dopamine function.ResultsObese individuals displayed lower gray and associated white matter volumes (P<0.05 family-wise error (FWE)- small volume corrected) compared with controls in the orbitofrontal cortex, striatum and insula. White matter integrity was reduced in obese individuals in fiber tracts including the external capsule, corona radiata, sagittal stratum, and the uncinate, inferior fronto-occipital, and inferior longitudinal fasciculi. Gray matter volume of the gyrus rectus at the medial edge of the orbitofrontal cortex predicted functional taste reward-learning response in frontal cortex, insula, basal ganglia, amygdala, hypothalamus and anterior cingulate cortex in control but not obese individuals.ConclusionsThis study indicates a strong association between medial orbitofrontal cortex volume and taste reinforcement-learning activation in the brain in control but not in obese women. Lower brain volumes in the orbitofrontal cortex and other brain regions associated with taste reward function as well as lower integrity of connecting pathways in obesity (OB) may support a more widespread disruption of reward pathways. The medial orbitofrontal cortex is an important structure in the termination of food intake and disturbances in this and related structures could contribute to overconsumption of food in obesity

    Food or friends? What motivates zebrafish (Danio rerio) performing a visual discrimination

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    This work was supported in part by the University of St Andrews’ QR block grant and the following grants awarded to CHB: NC3Rs G1000053; BBSRC BB/M007863; Leverhulme RPG-2016-143. CHB and VJB are Members of the Royal Society Industry Fellows’ College.As a model organism, zebrafish have much to offer neuroscientific research and they are increasingly being used in behavioral neuroscience, for example to study the genetics of learning and memory. As fish are often considered “less clever” than mammals, it is important to understand how they learn and to establish optimal testing conditions. In this study, we compared the efficacy of food reinforcement and social stimuli in supporting Pavlovian conditioning, Pavlovian-to-instrumental transfer, and acquisition of a two-alternative forced choice visual discrimination. Although equally effective in conditioning and in motivating discrimination learning, fish responded with shorter latencies when they were anticipating food but responded for a greater number of trials when anticipating the social stimulus. After learning, the reward was changed: food-reinforcement was replaced with the social stimulus and vice versa. Performance accuracy did not change, but response latency did: the group previously rewarded with food, but now rewarded with the social stimulus, showed a decrease in response vigor. This is a negative contrast effect, which is well established in rats, but was thought to be absent in fish because they lacked goal representation. Our results show that zebrafish, like rats, do have goal representations. Furthermore, we have shown that whereas food has greater incentive salience than social stimuli, fish become satiated rapidly, but motivation to seek social stimuli is sustained. We conclude that zebrafish are well motivated by a mixed economy of social stimuli and food.PostprintPeer reviewe

    Bacterial Infection Elicits Heat Shock Protein 72 Release from Pleural Mesothelial Cells

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    Heat shock protein 70 (HSP70) has been implicated in infection-related processes and has been found in body fluids during infection. This study aimed to determine whether pleural mesothelial cells release HSP70 in response to bacterial infection in vitro and in mouse models of serosal infection. In addition, the in vitro cytokine effects of the HSP70 isoform, Hsp72, on mesothelial cells were examined. Further, Hsp72 was measured in human pleural effusions and levels compared between non-infectious and infectious patients to determine the diagnostic accuracy of pleural fluid Hsp72 compared to traditional pleural fluid parameters. We showed that mesothelial release of Hsp72 was significantly raised when cells were treated with live and heat-killed Streptococcus pneumoniae. In mice, intraperitoneal injection of S. pneumoniae stimulated a 2-fold increase in Hsp72 levels in peritoneal lavage (p<0.01). Extracellular Hsp72 did not induce or inhibit mediator release from cultured mesothelial cells. Hsp72 levels were significantly higher in effusions of infectious origin compared to non-infectious effusions (p<0.05). The data establish that pleural mesothelial cells can release Hsp72 in response to bacterial infection and levels are raised in infectious pleural effusions. The biological role of HSP70 in pleural infection warrants exploration

    Microscopics of Extremal Kerr from Spinning M5 Branes

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    We show that the spinning magnetic one-brane in minimal five-dimensional supergravity admits a decoupling limit that interpolates smoothly between a self-dual null orbifold of AdS_3 \times S^2 and the near-horizon limit of the extremal Kerr black hole times a circle. We use this interpolating solution to understand the field theory dual to spinning M5 branes as a deformation of the Discrete Light Cone Quantized (DLCQ) Maldacena-Stominger-Witten (MSW) CFT. In particular, the conformal weights of the operators dual to the deformation around AdS_3 \times S^2 are calculated. We present pieces of evidence showing that a CFT dual to the four-dimensional extremal Kerr can be obtained from the deformed MSW CFT.Comment: 5 page

    A proposal for a comprehensive grading of Parkinson's disease severity combining motor and non-motor assessments: meeting an unmet need.

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    Non-motor symptoms are present in Parkinson's disease (PD) and a key determinant of quality of life. The Non-motor Symptoms Scale (NMSS) is a validated scale that allows quantifying frequency and severity (burden) of NMS. We report a proposal for using NMSS scores to determine levels of NMS burden (NMSB) and to complete PD patient classification
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