248 research outputs found
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Aerosol scattering and absorption during the EUCAARI-LONGREX flights of the Facility for Airborne Atmospheric Measurements (FAAM) BAe-146: can measurements and models agree?
Scattering and absorption by aerosol in anthropogenically
perturbed air masses over Europe has been measured
using instrumentation flown on the UK’s BAe-146-301
large Atmospheric Research Aircraft (ARA) operated by the
Facility for Airborne Atmospheric Measurements (FAAM)
on 14 flights during the EUCAARI-LONGREX campaign
in May 2008. The geographical and temporal variations of
the derived shortwave optical properties of aerosol are presented. Values of single scattering albedo of dry aerosol at 550 nm varied considerably from 0.86 to near unity, with a campaign average of 0.93 ± 0.03. Dry aerosol optical depths ranged from 0.030 ± 0.009 to 0.24 ± 0.07. An optical properties closure study comparing calculations from composition data and Mie scattering code with the measured properties is presented. Agreement to within measurement uncertainties of 30% can be achieved for both scattering and absorption,but the latter is shown to be sensitive to the refractive indices chosen for organic aerosols, and to a lesser extent black carbon, as well as being highly dependent on the accuracy of the absorption measurements. Agreement with the measured absorption can be achieved either if organic carbon is assumed to be weakly absorbing, or if the organic aerosol is purely scattering and the absorption measurement is an overestimate due to the presence of large amounts of organic carbon. Refractive
indices could not be inferred conclusively due to this
uncertainty, despite the enhancement in methodology compared
to previous studies that derived from the use of the
black carbon measurements. Hygroscopic growth curves derived
from the wet nephelometer indicate moderate water uptake
by the aerosol with a campaign mean f (RH) value (ratio
in scattering) of 1.5 (range from 1.23 to 1.63) at 80% relative humidity. This value is qualitatively consistent with the major chemical components of the aerosol measured by the aerosol mass spectrometer, which are primarily mixed organics and nitrate and some sulphate
Enhancement of the aerosol direct radiative effect by semi-volatile aerosol components: airborne measurements in North-Western Europe
A case study of atmospheric aerosol measurements exploring the impact of the vertical distribution of aerosol chemical composition upon the radiative budget in North-Western Europe is presented. Sub-micron aerosol chemical composition was measured by an Aerodyne Aerosol Mass Spectrometer (AMS) on both an airborne platform and a ground-based site at Cabauw in the Netherlands. The examined period in May 2008 was characterised by enhanced pollution loadings in North-Western Europe and was dominated by ammonium nitrate and Organic Matter (OM). Both ammonium nitrate and OM were observed to increase with altitude in the atmospheric boundary layer. This is primarily attributed to partitioning of semi-volatile gas phase species to the particle phase at reduced temperature and enhanced relative humidity. Increased ammonium nitrate concentrations in particular were found to strongly increase the ambient scattering potential of the aerosol burden, which was a consequence of the large amount of associated water as well as the enhanced mass. During particularly polluted conditions, increases in aerosol optical depth of 50–100% were estimated to occur due to the observed increase in secondary aerosol mass and associated water uptake. Furthermore, the single scattering albedo was also shown to increase with height in the boundary layer. These enhancements combined to increase the negative direct aerosol radiative forcing by close to a factor of two at the median percentile level. Such increases have major ramifications for regional climate predictions as semi-volatile components are often not included in aerosol models.
The results presented here provide an ideal opportunity to test regional and global representations of both the aerosol vertical distribution and subsequent impacts in North-Western Europe. North-Western Europe can be viewed as an analogue for the possible future air quality over other polluted regions of the Northern Hemisphere, where substantial reductions in sulphur dioxide emissions have yet to occur. Anticipated reductions in sulphur dioxide in polluted regions will result in an increase in the availability of ammonia to form ammonium nitrate as opposed to ammonium sulphate. This will be most important where intensive agricultural practises occur. Our observations over North-Western Europe, a region where sulphur dioxide emissions have already been reduced, indicate that failure to include the semi-volatile behaviour of ammonium nitrate will result in significant errors in predicted aerosol direct radiative forcing. Such errors will be particularly significant on regional scales
Developing resources to facilitate culturally-sensitive service planning and delivery – doing research inclusively with people with learning disabilities
Background Black, Asian and minority ethnic people with learning disabilities face inequities in health and social care provision. Lower levels of service uptake and satisfaction with services have been reported, however, this is largely based on the views of carers. The ‘Access to Social Care: Learning Disabilities (ASC-LD)’ study sought to explore the views and experiences of social support services among adults with learning disabilities from Black, Asian and minority ethnic communities. Interviews with 32 Black, Asian and minority ethnic adults with learning disabilities were conducted to explore participants’ cultural identities, their understanding and experience of ‘support’. The views and experiences expressed in the ASC-LD study were used in the ‘Tools for Talking project’ to develop a suite of resources designed to facilitate culturally-sensitive communication and information-sharing, service planning and delivery through improved mutual understanding between providers and users of services. This paper describes the Tools for Talking project which sought to co-develop the resources through a partnership event. Methods An inclusive approach was adopted to address issues that are important to people with learning disabilities, to represent their views and experiences, and to involve Black, Asian and minority ethnic people with learning disabilities in the research process. Partnerships were developed with provider organisations and service users who were invited to a ‘Partnership Event’. Collaborators at the partnership event were asked to comment on and evaluate draft resources which included a series of videos and activities to explore topics that emerged as important in the ASC-LD study. Their comments were collated and the tools developed as they suggested. Results Using the results from the ASC-LD study helped to ensure that the draft resources were relevant to service users, addressing topics that were important to them. The partnership event was an effective method to collaborate with a relatively large number of stakeholders. However, the event was resource intensive and required substantial planning to ensure active and meaningful participation. Considerations, such as inviting stakeholders, developing the programme and selecting a venue are discussed. Conclusions The partnership approach has led to the development of a set of five illustrative videos and accompanying activities that address issues that emerged from the collaborative process including: culture, activities, support from staff, important people, choices and independence. These resources are freely available at: www.Toolsfortalking.co.uk. They are designed to be used by users and providers of services, but may also be useful in other settings
Acceptance or rejection? The social experiences of children with special educational needs and disabilities within a mainstream primary school
This article details a study which investigated the social acceptance and friendships of children with SEND, and their typically developing peers, at a mainstream primary school in the North West of England. Participants were 29 children aged five and six years old, separated into three groups; typically developing children, children who were being monitored for SEND, and children with formally identified SENDs. With the use of a peer nomination sociometric technique, findings revealed that children with SEND had less promising peer relations and friendships compared to children tracked for SEND and their typically developing peers, consequently questioning the mainstream ‘ideal’. © 2018, © 2018 ASPE
Evidence for a nuclear compartment of transcription and splicing located at chromosome domain boundaries
The nuclear topography of splicing snRNPs, mRNA transcripts and chromosome domains in various mammalian cell types are described. The visualization of splicing snRNPs, defined by the Sm antigen, and coiled bodies, revealed distinctly different distribution patterns in these cell types. Heat shock experiments confirmed that the distribution patterns also depend on physiological parameters. Using a combination of fluorescencein situ hybridization and immunodetection protocols, individual chromosome domains were visualized simultaneously with the Sm antigen or the transcript of an integrated human papilloma virus genome. Three-dimensional analysis of fluorescence-stained target regions was performed by confocal laser scanning microscopy. RNA transcripts and components of the splicing machinery were found to be generally excluded from the interior of the territories occupied by the individual chromosomes. Based on these findings we present a model for the functional compartmentalization of the cell nucleus. According to this model the space between chromosome domains, including the surface areas of these domains, defines a three-dimensional network-like compartment, termed the interchromosome domain (ICD) compartment, in which transcription and splicing of mRNA occurs
TNF-a and IL-10 levels in tracheobronchial lavage of ventilated preterm infants and subsequent lung function
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Does Gender Influence Colour Choice in the Treatment of Visual Stress?
Purpose
Visual Stress (VS) is a condition in which words appear blurred, in motion, or otherwise distorted when reading. Some people diagnosed with VS find that viewing black text on white paper through coloured overlays or precision tinted lenses (PTLs) reduces symptoms attributed to VS. The aim of the present study is to determine whether the choice of colour of overlays or PTLs is influenced by a patient’s gender.
Methods
Records of all patients attending a VS assessment in two optometry practices between 2009 and 2014 were reviewed retrospectively. Patients who reported a significant and consistent reduction in symptoms with either overlay and or PTL were included in the analysis. Overlays and PTLs were categorized as stereotypical male, female or neutral colours based on gender preferences as described in the literature. Chi-square analysis was carried out to determine whether gender (across all ages or within age groups) was associated with overlay or PTL colour choice.
Results
279 patients (133 males and 146 females, mean age 17 years) consistently showed a reduction in symptoms with an overlay and were included. Chi-square analysis revealed no significant association between the colour of overlay chosen and male or female gender (Chi-square 0.788, p = 0.674). 244 patients (120 males and 124 females, mean age 24.5 years) consistently showed a reduction in symptoms with PTLs and were included. Chi-square analysis revealed a significant association between stereotypical male/female/neutral colours of PTLs chosen and male/female gender (Chi-square 6.46, p = 0.040). More males preferred stereotypical male colour PTLs including blue and green while more females preferred stereotypical female colour PTLs including pink and purple.
Conclusions
For some VS patients, the choice of PTL colour is influenced not only by the alleviation of symptoms but also by other non-visual factors such as gender
Surfactant phosphatidylcholine half-life and pool size measurements in premature baboons developing bronchopulmonary dysplasia
Because minimal information is available about surfactant metabolism in
bronchopulmonary dysplasia, we measured half-lives and pool sizes of
surfactant phosphatidylcholine in very preterm baboons recovering from
respiratory distress syndrome and developing bronchopulmonary dysplasia,
using stable isotopes, radioactive isotopes, and direct pool size
measurements. Eight ventilated premature baboons received (2)H-DPPC
(dipalmitoyl phosphatidylcholine) on d 5 of life, and radioactive
(14)C-DPPC with a treatment dose of surfactant on d 8. After 14 d, lung
pool sizes of saturated phosphatidylcholine were measured. Half-life of
(2)H-DPPC (d 5) in tracheal aspirates was 28 +/- 4 h (mean +/- SEM).
Half-life of radioactive DPPC (d 8) was 35 +/- 4 h. Saturated
phosphatidylcholine pool size measured with stable isotopes on d 5 was 129
+/- 14 micro mol/kg, and 123 +/- 11 micro mol/kg on d 14 at autopsy.
Half-lives were comparable to those obtained at d 0 and d 6 in our
previous baboon studies. We conclude that surfactant metabolism does not
change during the early development of bronchopulmonary dysplasia, more
specifically, the metabolism of exogenous surfactant on d 8 is similar to
that on the day of birth. Surfactant pool size is low at birth, increases
after surfactant therapy, and is kept constant during the first 2 wk of
life by endogenous surfactant synthesis. Measurements with stable isotopes
are comparable to measurements with radioactive tracers and measurements
at autopsy
Elevated platelet-derived growth factor-BB concentrations in premature neonates who develop chronic lung disease
BACKGROUND: Chronic lung disease (CLD) in the preterm newborn is associated with inflammation and fibrosis. Platelet-derived growth factor-BB (PDGF-BB), a potent chemotactic growth factor, may mediate the fibrotic component of CLD. The objectives of this study were to determine if tracheal aspirate (TA) concentrations of PDGF-BB increase the first 2 weeks of life in premature neonates undergoing mechanical ventilation for respiratory distress syndrome (RDS), its relationship to the development of CLD, pulmonary hemorrhage (PH) and its relationship to airway colonization with Ureaplasma urealyticum (Uu). METHODS: Infants with a birth weight less than 1500 grams who required mechanical ventilation for RDS were enrolled into this study with parental consent. Tracheal aspirates were collected daily during clinically indicated suctioning. Uu cultures were performed on TA collected in the first week of life. TA supernatants were assayed for PDGF-BB and secretory component of IgA concentrations using ELISA techniques. RESULTS: Fifty premature neonates were enrolled into the study. Twenty-eight infants were oxygen dependent at 28 days of life and 16 infants were oxygen dependent at 36 weeks postconceptual age. PDGF-BB concentrations peaked between 4 and 6 days of life. Maximum PDGF-BB concentrations were significantly higher in infants who developed CLD or died from respiratory failure. PH was associated with increased risk of CLD and was associated with higher PDGF-BB concentrations. There was no correlation between maximum PDGF-BB concentrations and Uu isolation from the airway. CONCLUSIONS: PDGF-BB concentrations increase in TAs of infants who undergo mechanical ventilation for RDS during the first 2 weeks of life and maximal concentrations are greater in those infants who subsequently develop CLD. Elevation in lung PDGF-BB may play a role in the development of CLD
The effect of premature extraction of primary teeth on the subsequent need for orthodontic treatment.
AIM: To investigate if premature extraction of primary teeth was associated with orthodontic need in the permanent dentition. STUDY DESIGN: This was a case-control study based on retrospective dental records. METHODS: As part of NHS (UK) Dental Epidemiology Programme a sample of 366, 12-year-old children from Bradford and Airedale were examined. The survey collected data on patient demographics, dental health status including orthodontic need. Data linkage was undertaken for those children participating in the NHS Dental Epidemiology Programme who had previously accessed the local Salaried Dental Service (SDS). For these children, retrospective dental information was collected about premature extraction of primary teeth. RESULTS: From the 366 children who were surveyed, 116 children had received treatment at the local SDS in the past. Significantly more children from ethnic minorities, low socioeconomic backgrounds and high caries rate (p < 0.001) were seen in the SDS. For the 107 children who attended SDS, an increased total number of primary teeth extractions was positively associated with orthodontic need (odds ratio:1.18, CI -1.01 to 1.37). STATISCTICS: Multilevel modelling was undertaken to identify variables associated with orthodontic need. CONCLUSIONS: In the study group, orthodontic need was significantly associated with the number of primary teeth extracted
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