267 research outputs found

    Pixel sensitivity variation in a CdTe-Medipix2 detector using poly-energetic x-rays

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    We have a 1-mm-thick cadmium telluride (CdTe) sensor bump-bonded to a Medipix2 readout chip. This detector has been characterized using a poly-energetic x-ray beam. Open beam images (i.e. without an attenuating specimen between the x-ray source and the detector) have been acquired at room temperature using the MARS-CT system. Profiles of various rows and columns were analyzed for one hundred, 35-ms exposures taken with a bias voltage of -300 V (operating in electron collection mode). A region of increased sensitivity is observed around the edges of the detector. A reasonably periodic, repeatable variation in pixel sensitivity is observed. Some small regions with very low sensitivity and others with zero signals are also observed. Surrounding these regions are circular rings of pixels with higher counts. At higher flux (higher tube current in the x-ray source) there is evidence of saturation of the detector assembly. In this paper we present our understanding of the origin of these features and demonstrate the improved image quality obtained after correcting for these variations

    Big Data and Geospatial Analysis

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    Design, Implementation and First Measurements with the Medipix Neutron Camera in CMS

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    The Medipix detector is the first device dedicated to measuring mixed-field radiation in the CMS cavern and able to distinguish between different particle types. Medipix2-MXR chips bump bonded to silicon sensors with various neutron conversion layers developed by the IEAP CTU in Prague were successfully installed for the 2008 LHC start-up in the CMS experimental and services caverns to measure the flux of various particle types, in particular neutrons. They have operated almost continuously during the 2010 run period, and the results shown here are from the proton run between the beginning of July and the end of October 2010. Clear signals are seen and different particle types have been observed during regular LHC luminosity running, and an agreement in the measured flux rate is found with the simulations. These initial results are promising, and indicate that these devices have the potential for further and future LHC and high energy physics applications as radiation monitoring devices for mixed field environments, including neutron flux monitoring. Further extensions are foreseen in the near future to increase the performance of the detector and its coverage for monitoring in CMS.Comment: 15 pages, 16 figures, submitted to JINS

    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

    Inclusive growth? The relationship between economic growth and poverty in British cities

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    There is growing concern in many developed economies that the benefits of economic growth are not shared equitably. This is particularly the case in the UK, where economic growth has been geographically uneven and often biased towards already affluent cities. Yet there is relatively little evidence on the relationship between growth and poverty in the UK. This paper addresses this gap with an analysis of the links between economic growth and poverty in British cities between 2000 – 2008. We find little evidence that output growth reduced poverty. While growth was associated with wage increases at the top of the distribution, it was not associated with wage growth below the median. And there was no relationship between economic growth and the low skilled employment rate. These results suggest that growth in this period was far from inclusive

    School nurses' experiences of delivering the UK HPV vaccination programme in its first year

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    Background: In the United Kingdom (UK) in September 2008, school nurses began delivering the HPV immunisation programme for girls aged 12 and 13 years old. This study offers insights from school nurses' perspectives and experiences of delivering this new vaccination programme. Methods: Thirty in-depth telephone interviews were conducted with school nurses working across the UK between September 2008 and May 2009. This time period covers the first year of the HPV vaccination programme in schools. School nurses were recruited via GP practices, the internet and posters targeted at school nurse practitioners. Results: All the school nurses spoke of readying themselves for a deluge of phone calls from concerned parents, but found that in fact few parents telephoned to ask for more information or express their concerns about the HPV vaccine. Several school nurses mentioned a lack of planning by policy makers and stated that at its introduction they felt ill prepared. The impact on school nurses' workload was spoken about at length by all the school nurses. They believed that the programme had vastly increased their workload leading them to cut back on their core activities and the time they could dedicate to offering support to vulnerable pupils. Conclusion: Overall the first year of the implementation of the HPV vaccination programme in the UK has exceeded school nurses' expectations and some of its success may be attributed to the school nurses' commitment to the programme. It is also the case that other factors, including positive newsprint media reporting that accompanied the introduction of the HPV vaccination programme may have played a role. Nevertheless, school nurses also believed that the programme had vastly increased their workload leading them to cut back on their core activities and as such they could no longer dedicate time to offer support to vulnerable pupils. This unintentional aspect of the programme may be worthy of further exploratio

    PPARα and PPARγ activation is associated with pleural mesothelioma invasion but therapeutic inhibition is ineffective

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    Mesothelioma is a cancer that typically originates in the pleura of the lungs. It rapidly invades the surrounding tissues, causing pain and shortness of breath. We compared cell lines injected either subcutaneously or intrapleurally and found that only the latter resulted in invasive and rapid growth. Pleural tumors displayed a transcriptional signature consistent with increased activity of nuclear receptors PPARα and PPARγ and with an increased abundance of endogenous PPAR-activating ligands. We found that chemical probe GW6471 is a potent, dual PPARα/γ antagonist with anti-invasive and anti-proliferative activity in vitro. However, administration of GW6471 at doses that provided sustained plasma exposure levels sufficient for inhibition of PPARα/γ transcriptional activity did not result in significant anti-mesothelioma activity in mice. Lastly, we demonstrate that the in vitro anti-tumor effect of GW6471 is off-target. We conclude that dual PPARα/γ antagonism alone is not a viable treatment modality for mesothelioma

    Ten commandments for the future of ageing research in the UK: a vision for action

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    Increases in longevity resulting from improvements in health care and living conditions together with a decrease in fertility rates have contributed to a shift towards an aged population profile. For the first time the UK has more people over age 60 than below 16 years of age. The increase in longevity has not been accompanied by an increase in disease-free life expectancy and research into ageing is required to improve the health and quality of life of older people. However, as the House of Lords reported, ageing research in the UK is not adequately structured and a clear vision and plan are urgently required. Hence, with the aim of setting a common vision for action in ageing research in the UK, a 'Spark Workshop' was organised. International experts from different disciplines related to ageing research gathered to share their perspectives and to evaluate the present status of ageing research in the UK. A detailed assessment of potential improvements was conducted and the prospective secondary gains were considered, which were subsequently distilled into a list of 'ten commandments'. We believe that these commandments, if followed, will help to bring about the necessary implementation of an action plan for ageing research in the UK, commensurate with the scale of the challenge, which is to transform the manifold opportunities of increased longevity into actual delivery of a society living not only for longer, but also healthier, wealthier and happier

    Dissolution of ionizable water-insoluble drugs: The combined effect of pH and surfactant

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    This study reports the results of the combined effect of pH and surfactant on the dissolution of piroxicam (PX), an ionizable water-insoluble drug in physiological pH. The intrinsic dissolution rate ( J total ) of PX was measured in the pH range from 4.0 to 7.8 with 0%, 0.5%, and 2.0% sodium lauryl sulfate (SLS) using the rotating disk apparatus. Solubility ( c total ) was also measured in the same pH and SLS concentration ranges. A simple additive model including an ionization (PX ↔ H + + PX − ) and two micellar solubilization equilibria (PX + micelle ↔ [PX] micelle , PX − + micelle ↔ [PX − ] micelle ) were considered in the convective diffusion reaction model. J total and c total of PX increased with increasing pH and SLS concentration in an approximately additive manner. Nonlinear regression analysis showed that observed experimental data were well described with the proposed model ( r 2 = 0.86, P < 0.001 for J total and r 2 = 0.98, P < 0.001 for c total ). The p K a value of 5.63 ± 0.02 estimated from c total agreed well with the reported value. The micellar solubilization equilibrium coefficient for the unionized drug was estimated to be 348 ± 77 L/mol, while the value for the ionized drug was nearly equal to zero. The diffusion coefficients of the species PX, PX − , and [PX] micelle were estimated from the experimental results as (0.93 ± 0.35) × 10 −5 , (1.4 ± 0.30) × 10 −5 , and (0.59 ± 0.21) × 10 −5 cm 2 /s, respectively. The total flux enhancement is less than the total solubility enhancement due to the smaller diffusion coefficients of the micellar species. This model may be useful in predicting the dissolution of an ionizable water insoluble drug as a function of pH and surfactant and for establishing in vitro – in vivo correlations, IVIVC, for maintaining bioequivalence of drug products. © 2000 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 89: 268–274, 2000Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34499/1/14_ftp.pd

    Effect of cadence on locomotor–respiratory coupling during upper-body exercise

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    Introduction: Asynchronous arm-cranking performed at high cadences elicits greater cardiorespiratory responses compared to low cadences. This has been attributed to increased postural demand and locomotor–respiratory coupling (LRC), and yet, this has not been empirically tested. This study aimed to assess the effects of cadence on cardiorespiratory responses and LRC during upper-body exercise. Methods: Eight recreationally-active men performed arm-cranking exercise at moderate and severe intensities that were separated by 10 min of rest. At each intensity, participants exercised for 4 min at each of three cadences (50, 70, and 90 rev min−1) in a random order, with 4 min rest-periods applied in-between cadences. Exercise measures included LRC via whole- and half-integer ratios, cardiorespiratory function, perceptions of effort (RPE and dyspnoea), and diaphragm EMG using an oesophageal catheter. Results: The prevalence of LRC during moderate exercise was highest at 70 vs. 50 rev min−1 (27 ± 10 vs. 13 ± 9%, p = 0.000) and during severe exercise at 90 vs. 50 rev min−1 (24 ± 7 vs. 18 ± 5%, p = 0.034), with a shorter inspiratory time and higher mean inspiratory flow (p < 0.05) at higher cadences. During moderate exercise, (Formula presented.) and fC were higher at 90 rev min−1 (p < 0.05) relative to 70 and 50 rev min−1 ((Formula presented.) 1.19 ± 0.25 vs. 1.05 ± 0.21 vs. 0.97 ± 0.24 L min−1; fC 116 ± 11 vs. 101 ± 13 vs. 101 ± 12 b min−1), with concomitantly elevated dyspnoea. There were no discernible cadence-mediated effects on diaphragm EMG. Conclusion: Participants engage in LRC to a greater extent at moderate-high cadences which, in turn, increase respiratory airflow. Cadence rate should be carefully considered when designing aerobic training programmes involving the upper-limbs
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