6,392 research outputs found
Environmental stability graphite/PMR-15 composites
During the past few years the Boeing Company was screening graphite composites for use in hot areas of engine nacelle structure. Structural and thermal analyses have shown that there is the potential for a 25 to 30 percent weight savings by using a graphite polyimide (Gr/PI) composite material in this type of structure. Work conducted on the NASA CASTS program (Composites for Advanced Space Transportation Systems) amply demonstrated the capability of Graphite/PMR-15 for short term service (125 hours) at temperatures up to 589 K (600 F). In addition, the CASTS program demonstrated that large structures could be fabricated using Gr/PMR-15. In commercial applications, however, the requirement exists for long term service capability (tens of thousands of hours) at temperatures ranging upwards from 449 K (350 F). The results of Graphite/PMR-15 materials characterization efforts conducted at Boeing are presented with emphasis on materials properties after isothermal aging at temperatures of 449 K (350 F) and above
How we Can change your mind: Anodal tDCS to Fp3 alters human stimulus representation and learning.
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.The aim of the current work is to advance our understanding of both the mechanisms controlling perceptual learning and the face inversion effect. In the three double blind experiments reported here (total N=144) we have shown that anodal tDCS stimulation (10 mins at 1.5 mA) delivered over the left DLPFC at Fp3 affects perceptual learning and drastically reduces the, usually robust, face inversion effect. In Experiment 1, we found a significantly reduced inversion effect in the anodal group compared to that in the sham group. Experiment 2 replicated the pattern of results found in Experiment 1. In both experiments recognition performance for upright faces in the anodal group was significantly impaired compared to that in the sham group. Finally, using an active control in Experiment 3 (same behavioural task but different tDCS targeted brain area) we showed that the same Fp3 anodal tDCS stimulation effect is not obtained when a different brain area is targeted.This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 743702 awarded to Ciro Civile. This project has also received funding from the Economic and Social Research Council (ESRC) New Investigator Grant (Ref. ES/R005532) awarded to Ciro Civile (PI) and I.P.L. McLaren (Co-I)
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Prevalence of iron deficiency in 62,685 women of seven race/ethnicity groups: The HEIRS Study.
BackgroundFew cross-sectional studies report iron deficiency (ID) prevalence in women of different race/ethnicity and ages in US or Canada.Materials and methodsWe evaluated screening observations on women who participated between 2001-2003 in a cross-sectional, primary care-based sample of adults ages ≥25 y whose observations were complete: race/ethnicity; age; transferrin saturation; serum ferritin; and HFE p.C282Y and p.H63D alleles. We defined ID using a stringent criterion: combined transferrin saturation <10% and serum ferritin <33.7 pmol/L (<15 μg/L). We compared ID prevalence in women of different race/ethnicity subgrouped by age and determined associations of p.C282Y and p.H63D to ID overall, and to ID in women ages 25-44 y with or without self-reported pregnancy.ResultsThese 62,685 women included 27,079 whites, 17,272 blacks, 8,566 Hispanics, 7,615 Asians, 449 Pacific Islanders, 441 Native Americans, and 1,263 participants of other race/ethnicity. Proportions of women with ID were higher in Hispanics and blacks than whites and Asians. Prevalence of ID was significantly greater in women ages 25-54 y of all race/ethnicity groups than women ages ≥55 y of corresponding race/ethnicity. In women ages ≥55 y, ID prevalence did not differ significantly across race/ethnicity. p.C282Y and p.H63D prevalence did not differ significantly in women with or without ID, regardless of race/ethnicity, age subgroup, or pregnancy.ConclusionsID prevalence was greater in Hispanic and black than white and Asian women ages 25-54 y. p.C282Y and p.H63D prevalence did not differ significantly in women with or without ID, regardless of race/ethnicity, age subgroup, or pregnancy
Assistant practitioners (APs) perceptions of their developing role and practice in radiography: Results from a national survey
Introduction: In 2000, the NHS Plan set out the government's plans for investment and reform across the NHS. Through the introduction of a new workforce at assistant practitioner (AP) level the Department of Health intended to implement new ways in which to deliver a more efficient service. At the time, little published information existed on the integration of these assistants into the contemporary radiography workforce. Publications were limited to experiences gained by various individual departments ranging in their perception of the role and education of APs. Further research was suggested to track the continuing implementation of the 4-tier structure, establish the precise nature and scope of the roles across Trusts and determine their impact on workload and patient care. Aim: To establish the number and employment locality of APs in radiography professions in England, and to explore their scope of applied practice. Method and materials: The study was conducted over three phases and employed a mixed methods design to address the aims and objectives. Phase I was a scoping exercise performed prior to data collection in which n = 226 radiography sites were identified for contact across England. Phase II utilized a questionnaire as data collection tool to investigate the role of APs in radiography and explore how their roles were integrated into the radiography workforce in England. Results from phase III of the study which utilized semi-structured qualitative interviews are not included in this paper. Conclusion and discussion: Key findings depict the nature and variety of roles and responsibilities undertaken by APs in radiography. This study was the first of its kind to identify the integration of APs in radiography across a sizable geographical region. There were mixed responses to the question asking APs if they were required to perform duties outside their scope of practice. Questionnaire data revealed that a high numbers of APs were working in areas under indirect supervision. Results from this study showed that APs, in some areas at least, were performing the roles of practitioners. Therefore further investigation is needed for new roles to develop criteria to determine which new roles should be the subject of statutory regulation. © 2011 The College of Radiographers
Switching off perceptual learning: tDCS to left DLPFC eliminates perceptual learning in humans.
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Perceptual learning can be acquired as a result of experience with stimuli that would otherwise be difficult to tell apart, and is often explained in terms of the modulation of feature salience by an error signal based on how well that feature can be predicted by the others that make up the stimulus. In this article we show that anodal transcranial Direct Current Stimulation (tDCS) at Fp3 directly influences this modulation process so as to eliminate and possibly reverse perceptual learning. In 2 experiments, anodal stimulation disrupted perceptual learning (indexed by an inversion effect) compared with sham (Experiment 1) or cathodal (Experiment 2) stimulation. Our findings can be interpreted as showing that anodal tDCS severely reduced or even abolished the modulation of salience based on error, greatly increasing generalization between stimuli. This result supports accounts of perceptual learning based on variations in salience as a consequence of pre-exposure, and opens up the possibility of controlling this phenomenon.IPLM and FV are supported by a grant from the ESRC (ES/J00815X/1), and FV is
supported by a starting grant from the European Research Council (ERC) under the European
Union's Seventh Framework Programme (FP7/2007-2013)/ ERC Grant Agreement No.
312445. CC was supported by an Overseas Scholarship from the International Office at the
University of Exeter and Yixuan Ku by the National Key Fundamental Research (973)
Program (2013CB329501) of China
Heterodyne detection of CO2 emission lines and wind velocities in the atmosphere of Venus
Strong 10 micrometer line emission from (c-12)(o-16)2 in the upper atmosphere of Venus was detected by heterodyne techniques. Observations of the absolute Doppler shift of the emission features indicate mean zonal wind velocities less than 10 m/sec in the upper atmosphere near the equator. No evidence was found of the 100 m/sec wind velocity implied by the apparent 4-day rotation period of ultraviolet cloud features
Heterodyne detection of CO2 emission lines and wind velocities in the atmosphere of Venus
Strong 10 micrometer line emission from (C-12)(O-16)2 in the upper atmosphere of Venus was detected by heterodyne techniques. Observations of the absolute Doppler shift of the emission features indicate mean zonal wind velocities less than 10 m/sec in the upper atmosphere near the equator. No evidence was found of the 100 m/sec wind velocity implied by the apparent 4-day rotation period of ultraviolet cloud features
The effect of scrambling upright and inverted faces on the N170
This is the author accepted manuscript. The final version is available from SAGE Publications via the DOI in this record.The face inversion effect refers to a decrement in performance when we try to recognise
familiar faces turned upside down (inverted), compared to familiar faces presented in their usual
(upright) orientation. Recently, we have demonstrated that the inversion effect can also be found
with checkerboards drawn from prototype-defined categories when the participants have been
trained with these categories, suggesting that factors such as expertise and the relationships
between stimulus features, may be important determinants of this effect. We also demonstrated
that the typical inversion effect on the N170 seen with faces is found with checkerboards,
suggesting that modulation of the N170 is a marker for disruption in the use of configural
information. In the present experiment, we first demonstrate that our scrambling technique
greatly reduces the inversion effect in faces. Following this, we used Event-Related Potentials
(ERPs) recorded while participants performed an Old/New recognition study on normal and
scrambled faces presented in both upright and inverted orientations to investigate the impact of
scrambling on the N170. We obtained the standard robust inversion effect for normal faces: The
N170 was both larger and delayed for normal inverted faces as compared to normal upright
faces, whereas a significantly reduced inversion effect was recorded for scrambled faces. These
results show that the inversion effect on the N170 is greater for normal compared to scrambled
faces, and we interpret the smaller effect for scrambled faces as being due to the reduction in
expertise for those faces consequent on scramblingThis project has received funding from the European Union’s Horizon 2020 research and
innovation programme under the Marie Sklodowska-Curie grant agreement No 74370
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