119 research outputs found
The atmospheric charged kaon/pion ratio using seasonal variation methods
Observed since the 1950's, the seasonal effect on underground muons is a well
studied phenomenon. The interaction height of incident cosmic rays changes as
the temperature of the atmosphere changes, which affects the production height
of mesons (mostly pions and kaons). The decay of these mesons produces muons
that can be detected underground. The production of muons is dominated by pion
decay, and previous work did not include the effect of kaons. In this work, the
methods of Barrett and MACRO are extended to include the effect of kaons. These
efforts give rise to a new method to measure the atmospheric K/ ratio at
energies beyond the reach of current fixed target experiments. These methods
were applied to data from the MINOS far detector. A method is developed for
making these measurements at other underground detectors, including OPERA,
Super-K, IceCube, Baksan and the MINOS near detector.Comment: 15 pages, 4 figures, submitted to Astropart. Phy
Investigating practice integration of independent prescribing by community pharmacists using normalization process theory: a cross-sectional survey.
Independent prescribing (IP) has not been extensively investigated in community pharmacy (CP). Normalization Process Theory (NPT) constructs help explain how interventions are integrated into practice and include: 'coherence' (understanding), 'cognitive participation' (what promotes engagement), 'collective action' (integration with existing systems), 'reflexive monitoring (evaluation). The aim of this study was to use NPT to investigate the integration of pharmacist IP in CP. NHS Scotland Pharmacy First Plus (PFP) is a community pharmacy IP service. Questionnaire items were developed using the NPT derived Normalisation MeAsure Development (NoMAD) tool for an online survey of all PFP IP pharmacists. Demographic data were analysed descriptively and scale scores (calculated from item scores for the 4 NPT constructs) were used for inferential analysis. There was a 73% (88/120) response rate. Greater than 90% 'strongly agreed' / 'agreed' to NoMAD items relating to most NPT constructs. However, responses to 'collective action' items were diverse with more participants answering 'neither agree nor disagree' or 'disagree'. A statistically significant difference in NPT construct scale scores with significant p-values (ranging from p<0.001 to p=0.033) was shown on all the NPT constructs for the variable 'On average, how often do you consult with patients under the PFP service?'. This theory-based work offers perspectives on IP integration within CP. Despite its geographic focus this work offers insights relevant to wider contexts on IP integration. It shows 'collective action' focused 'organisation' and 'group process' challenges with a need for further work on staff training, resource availability and utilisation, working relationships, communication and management
Sudden stratospheric warmings seen in MINOS deep underground muon data
The rate of high energy cosmic ray muons as measured underground is shown to be strongly correlated with upper-air temperatures during short-term atmospheric (10-day) events. The effects are seen by correlating data from the MINOS underground detector and temperatures from the European Centre for Medium Range Weather Forecasts during the winter periods from 2003-2007. This effect provides an independent technique for the measurement of meteorological conditions and presents a unique opportunity to measure both short and long-term changes in this important part of the atmosphere. Citation: Osprey, S., et al. (2009), Sudden stratospheric warmings seen in MINOS deep underground muon data, Geophys. Res. Lett., 36, L05809, doi: 10.1029/2008GL036359
The tropical route of quasi-biennial oscillation (QBO) teleconnections in a climate model
The influence of the quasi-biennial oscillation (QBO) on tropical climate is demonstrated using 500-year pre-industrial control simulations from the Met Office Hadley Centre model.
Robust precipitation responses to the phase of the QBO are diagnosed in the model, which show zonally asymmetric patterns that resemble the El Niño–Southern Oscillation (ENSO) impacts. These patterns are found because the frequency of ENSO events for each QBO phase is significantly different in these simulations, with more El Niño events found under the westerly phase of the QBO (QBOW) and more La Niña events for the easterly phase (QBOE). The QBO–ENSO relationship is non-stationary and subject to decadal variability in both models and observations. In addition, regression analysis shows that there is a QBO signal in precipitation that is independent of ENSO.
No evidence is found to suggest that these QBO–ENSO relationships are caused by ENSO modulating the QBO in the simulations.
A relationship between the QBO and a dipole of precipitation in the Indian Ocean is also found in models and observations in boreal fall, characterised by a wetter western Indian Ocean and drier conditions in the eastern part for QBOW and the opposite under QBOE conditions.
The Walker circulation is significantly weaker during QBOW compared to QBOE, which could explain the observed and simulated zonally asymmetric precipitation responses at equatorial latitudes, as well as the more frequent El Niño events during QBOW. Further work, including targeted model experiments, is required to better understand the mechanisms causing these relationships between the QBO and tropical convection.</p
Global distributions of overlapping gravity waves in HIRDLS data
Data from the High Resolution Dynamics Limb Sounder (HIRDLS) instrument on
NASA's Aura satellite are used to investigate the relative numerical
variability of observed gravity wave packets as a function of both horizontal
and vertical wavenumber, with support from the Sounding of the Atmosphere
using Broadband Emission Radiometry (SABER) instrument on TIMED. We see that
these distributions are dominated by large vertical and small horizontal
wavenumbers, and have a similar spectral form at all heights and latitudes,
albeit with important differences. By dividing our observed wavenumber
distribution into particular subspecies of waves, we demonstrate that these
distributions exhibit significant temporal and spatial variability, and that
small-scale variability associated with particular geophysical phenomena such
as the monsoon arises due to variations in specific parts of the observed
spectrum. We further show that the well-known Andes/Antarctic Peninsula
gravity wave hotspot during southern winter, home to some of the largest wave
fluxes on the planet, is made up of relatively few waves, but with a
significantly increased flux per wave due to their spectral characteristics.
These results have implications for the modelling of gravity wave phenomena
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Possible impacts of a future grand solar minimum on climate: Stratospheric and global circulation changes.
This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/2014JD022022A future decline in solar activity would not offset projected global warmingA future decline in solar activity could have larger regional effects in winterTop-down mechanism contributes to Northern Hemisphere regional response.LJG and ACM were supported by the National Centre for Atmospheric Science's Climate Directorate. ACM also acknowledges support from the ERC ACCI project no. 267760 and an AXA Postdoctoral Fellowship. SI and AAS were supported by the Joint DECC/Defra Met Office Hadley Centre Climate Programme (GA01101). LJG and JAA were supported by a grant from the National Environmental Research Council
HIRDLS Science Meeting Oxford (20 Sep 2006) Presentations
Selection of presentations given at the HIRDLS Science Meeting Oxford on the 20th September 2006
Climate Impacts From a Removal of Anthropogenic Aerosol Emissions
Limiting global warming to 1.5 or 2.0°C requires strong mitigation of anthropogenic greenhouse gas (GHG) emissions. Concurrently, emissions of anthropogenic aerosols will decline, due to coemission with GHG, and measures to improve air quality. However, the combined climate effect of GHG and aerosol emissions over the industrial era is poorly constrained. Here we show the climate impacts from removing present-day anthropogenic aerosol emissions and compare them to the impacts from moderate GHG-dominated global warming. Removing aerosols induces a global mean surface heating of 0.5–1.1°C, and precipitation increase of 2.0–4.6%. Extreme weather indices also increase. We find a higher sensitivity of extreme events to aerosol reductions, per degree of surface warming, in particular over the major aerosol emission regions. Under near-term warming, we find that regional climate change will depend strongly on the balance between aerosol and GHG forcing
Surface impacts of the Quasi Biennial Oscillation
Teleconnections between the Quasi Biennial Oscillation (QBO) and the Northern Hemisphere zonally averaged zonal winds, mean sea level pressure (mslp) and tropical precipitation are explored. The standard approach that defines the QBO using the equatorial zonal winds at a single pressure level is compared with the empirical orthogonal function approach that characterizes the vertical profile of the equatorial winds. Results are interpreted in terms of three potential routes of influence, referred to as the tropical, subtropical and polar routes. A novel technique is introduced to separate responses via the polar route that are associated with the stratospheric polar vortex, from the other two routes. A previously reported mslp response in January, with a pattern that resembles the positive phase of the North Atlantic Oscillation under QBO westerly conditions, is confirmed and found to be primarily associated with a QBO modulation of the stratospheric polar vortex. This mid-winter response is relatively insensitive to the exact height of the maximum QBO westerlies and a maximum positive response occurs with westerlies over a relatively deep range between 10 and 70hPa. Two additional mslp responses are reported, in early winter (December) and late winter (February/March). In contrast to the January response the early and late winter responses show maximum sensitivity to the QBO winds at ∼ 20 and ∼ 70hPa respectively, but are relatively insensitive to the QBO winds in between ( ∼ 50hPa). The late winter response is centred over the North Pacific and is associated with QBO influence from the lowermost stratosphere at tropical/subtropical latitudes in the Pacific sector. The early winter response consists of anomalies over both the North Pacific and Europe, but the mechanism for this response is unclear. Increased precipitation occurs over the tropical western Pacific under westerly QBO conditions, particularly during boreal summer, with maximum sensitivity to the QBO winds at 70hPa. The band of precipitation across the Pacific associated with the Inter-tropical Convergence Zone (ITCZ) shifts southward under QBO westerly conditions. The empirical orthogonal function (EOF)-based analysis suggests that this ITCZ precipitation response may be particularly sensitive to the vertical wind shear in the vicinity of 70hPa and hence the tropical tropopause temperatures
Scottish adherence to antihypertensive medication in the elderly: promoting evidence-based community pharmacy services.
Background and Objective: Detection and treatment of hypertension continues to be a major public health challenge affecting between 30 and 45% of the general population, increasing steeply with age. Many studies have shown the benefit of antihypertensive agents in improving clinical outcomes. However, their effectiveness is dependent on persistent adherence to prescribed medication. Objectives (1) to assess adherence to antihypertensive medication; (2) to examine patient-specific factors associated with antihypertensive medication adherence among Scottish adults aged 65 years plus. Design: Pre-registration pharmacy trainees (pre-regs) undertaking postgraduate placement-in-practice based in community pharmacies across Scotland were invited to take part. Each pre-reg invited and consented up to 15 patients (aged 65 plus; at least one prescribed medication) presenting with a prescription which indicated treatment for hypertension, to take part in a telephone interview. Pre-regs added pharmacy dispensing data to a paper-based structured data collection tool for later online data entry. The structured interview focused on patient's beliefs about medicines and medication adherence. The study had NHS ethical approval. Results: Of the 130 pre-regs working in community pharmacy in Scotland 92% (n=119) took part with a patient-participant response rate of 75% (n=1332). 94% of respondents always-or-often strive to follow doctor's instructions and have a strict routine for use of their regular medicines. 87% rarely-or-never get confused about their medicines. 78% of respondents believed their medication prevented them becoming ill; unpleasant side effects were reported by 8%. 93% said taking medication did not disrupt their life. Respondents had visited a medical practice twice in previous 6 months. 69% reported normal blood pressure. 49% of respondents had previously smoked daily; 13% currently smoke. Conclusion: The SAAME study provides strong evidence of patients adhering to antihypertensive medication, also a model for promoting evidenced-based community pharmacy services: public health data year-on-year; raise the profile of clinical research in community pharmacy services. Feedback suggests pharmacies have concerns about telephone interviews preventing calls coming in so would prefer the option of face-to-face interviews; also direct online entry of data, and; online consent forms for the pre-regs. Future research is planned around evaluating pre-reg engagement, training needs, impact on community pharmacy based tutors and staff
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