Fast Response of Boundary Layer Clouds to Climate Change

Boundary layer clouds make up a large part of the total cloud cover across the world. These clouds play an important role in the vertical transport of heat, moisture, and momentum from the surface through the boundary layer. Thus these clouds have a significant impact on the vertical structure of the boundary layer. They not only have an impact on the vertical structure, but also have a significant impact on the Earth's radiation budget. Normally boundary layer clouds generally have a higher albedo compared to the surface below them and as a result there is an increased reflectance of solar radiation. Due to these strong impacts on the atmospheric conditions it is important that these boundary layer clouds and their processes are taken into account when simulating (future) climates. One of the largest uncertainties in climate projections is related to the uncertainty in how boundary layer clouds respond to climate change. This uncertainty in cloud feedback is primarily related to the use of general circulation models (GCMs) in climate projections. As GCMs have a very coarse resolution they require parameterizations to represent boundary layer processes and clouds. These parameterizations are imperfect and therefore the GCMs have difficulties in representing the radiative effects of clouds. Therefore high resolution models such as large-eddy simulations (LESs), which require less parameterizations are used to study boundary layer processes and clouds. Several LES studies have been conducted on climate projections, where a perturbation of a future climate is applied to the model. These perturbations include increases in sea surface temperature and/or the concentration of CO2. In future climates it is anticipated that the atmosphere will become warmer and therefore it can contain a much larger concentration of moisture. This increased moisture can lead to the presence of very humid layers above the boundary layer, known as elevated moisture layers, which have already been observed in nature. This thesis investigates the response of boundary layer clouds to the presence of an elevated moisture layer, based on observed conditions during research flight 4 of the first Next Generation-aircraft Remote-sensing (NARVAL) campaign. This study is divided into three main sections. The first and second parts of the analysis focus on comparing the LES to observations recorded during the campaign in order to test the representativeness of the model. Following this the response of boundary layer clouds to an elevated moisture layer perturbation is investigated. To this purpose, LESs are initially generated at the locations of the 11 dropsondes launched during the fourth research flight of the NARVAL campaign, which took place on December 14th 2013. Initial comparisons indicate the LES shows good ability in representing the atmospheric conditions observed, showing a strong evolution of the boundary layer over time which has previously been observed at the Barbados Cloud Observatory. The results from the simulations also indicate that the LES has an ability to capture the height of the boundary layer inversion. There are some limitations in capturing the strength of the inversion, which is potentially related to the extremely dry conditions observed above the boundary layer. The LES is then compared to retrievals from the High Altitude and Long Range Aircraft (HALO) Microwave Package (HAMP) instrument. In order to take the flight path into account the mean large-scale profiles, from the locations of 9 dropsondes, are used to derive a composite case. The aim of using the composite case was to investigate whether the LES has the ability to capture the large variability in the integrated water vapor and liquid water path retrieved throughout the flight path. Using a large domain LES, with horizontal extent reaching 51.2 km2 the variability in integrated water vapor and liquid water path does approach the retrieved values, while domains with a smaller domains have a larger underestimation of the variability. The simulations indicate a correlation between the degree of organization, Iorg and the precipitation flux, variability in integrated water vapor, and variability in liquid water path. A similar slope of dependency between the variability in integrated water vapor and Iorg is found, across all simulations. In comparison the slopes of dependency between the Iorg and both the variability in liquid water path and precipitation flux values differ between each of the simulations. This suggests that there are different structures in the clouds between simulations and that the Iorg is highly controlled by the water vapor distribution. These studies give confidence that the LES has the ability to capture observed conditions, which is important for simulating future climates. For the investigation into the impact of an elevated moisture layer and the corresponding response of the boundary layer clouds, two sets of simulations were generated on a 25.6 km2 domain using the composite case setup from the HAMP comparison. These two sets of simulations include a control simulation and a set of 5 elevated moisture layer simulations with varying elevated moisture layer depth. While the elevated moisture layer has a significant impact on the atmospheric conditions in the free troposphere, while the largest impact in the boundary layer occurs in the cloud fraction. A decrease in the cloud layer depth is found with increasing elevated moisture layer depth. The impact is not however limited to the vertical structure of the clouds with a significant impact also found in the radiative fluxes throughout the lower troposphere. In order to determine the response of the boundary layer clouds to a change in climate, represented here by the elevated moisture layer, the cloud radiative effect is calculated at the top of the cloud layer. The results indicate there is a positive feedback from the boundary layer clouds produced in response to the elevated moisture layer, which indicates that these clouds have a warming effect on the boundary layer

Feasibility Evaluation of Radioimmunoguided Surgery of Breast Cancer

Breast-conserving surgery involves completely excising the tumour while limiting the amount of normal tissue removed, which is technically challenging to achieve, especially given the limited intraoperative guidance available to the surgeon. This study evaluates the feasibility of radioimmunoguided surgery (RIGS) to guide the detection and delineation of tumours intraoperatively. The 3D point-response function of a commercial gamma-ray-detecting probe (GDP) was determined as a function of radionuclide (131I, 111In, 99mTc), energy-window threshold, and collimator length (0.0–3.0-cm). This function was used to calculate the minimum detectable tumour volumes (MDTVs) and the minimum tumour-to-background activity concentration ratio (T:B) for effective delineation of a breast tumour model. The GDP had larger MDTVs and a higher minimum required T:B for tumour delineation with 131I than with 111In or 99mTc. It was shown that for 111In there was a benefit to using a collimator length of 0.5-cm. For the model used, the minimum required T:B required for effective tumour delineation was 5.2 ± 0.4. RIGS has the potential to significantly improve the accuracy of breast-conserving surgery; however, before these benefits can be realized, novel radiopharmaceuticals need to be developed that have a higher specificity for cancerous tissue in vivo than what is currently available

A rapid protocol for generating arthropod DNA barcodes suitable for use with undergraduate students

We provide a protocol for rapid DNA extraction from spiders suitable for undergraduate practical sessions. Students who were previously naïve to the theory and laboratory technique of DNA barcoding were successfully able to extract and recover 29 DNA sequences from 16 species of small spiders in the family Linyphiidae. We anticipate that with careful selection of specimens, undergraduate students could participate in sessions which both benefit their professional development and further taxonomic understanding across a variety of organisms.PostprintPostprintPeer reviewe

A systematic review to evaluate the evidence base for the World Health Organization's adopted hand hygiene technique for reducing the microbial load on the hands of healthcare workers

Background: Effective hand hygiene prevents healthcare-associated infections. This systematic review evaluates the evidence for the World Health Organization's (WHO) technique in reducing the microbial load on the hands of healthcare workers (HCWs). Methods: This study was conducted in accordance with Joanna Briggs Protocol 531. Index and free-text terms for technique, HCW, and microbial load were searched in CINAHL, Medline, Web of Science, Mednar, Proquest, and Google Scholar. Inclusion criteria were articles in English that evaluated the WHO 6-step hand hygiene technique for healthcare staff. Two reviewers independently performed quality assessment and data extraction. Results: All 7 studies found that the WHO technique reduced bacterial load on HCW hands, but the strongest evidence came from 3 randomized controlled trials, which reported conflicting evidence. One study found no difference in the effectiveness of the WHO 6-step technique compared to the Centers for Disease Control and Prevention's 3-step technique (P =.08); another study found the WHO 6-step technique to be more effective (P =.02); and the third study found that a modified 3-step technique was more effective than the 6-step technique (P =.021). Conclusions: This review provides evidence of the effectiveness of the WHO technique but does not identify the most effective hand hygiene technique. Questions to be addressed by further research are identified. Meanwhile, current practices should continue

A compilation, tabulation and analysis of spelling errors made by pupils in grades four, five, and six in free writing of sentences using given stimuli words

Thesis (M.A.)--Boston Universit

Inequalities in physical comorbidity:a longitudinal comparative cohort study of people with severe mental illness in the UK

OBJECTIVES: Little is known about the prevalence of comorbidity rates in people with severe mental illness (SMI) in UK primary care. We calculated the prevalence of SMI by UK country, English region and deprivation quintile, antipsychotic and antidepressant medication prescription rates for people with SMI, and prevalence rates of common comorbidities in people with SMI compared with people without SMI. DESIGN: Retrospective cohort study from 2000 to 2012. SETTING: 627 general practices contributing to the Clinical Practice Research Datalink, a UK primary care database. PARTICIPANTS: Each identified case (346 551) was matched for age, sex and general practice with 5 randomly selected control cases (1 732 755) with no diagnosis of SMI in each yearly time point. OUTCOME MEASURES: Prevalence rates were calculated for 16 conditions. RESULTS: SMI rates were highest in Scotland and in more deprived areas. Rates increased in England, Wales and Northern Ireland over time, with the largest increase in Northern Ireland (0.48% in 2000/2001 to 0.69% in 2011/2012). Annual prevalence rates of all conditions were higher in people with SMI compared with those without SMI. The discrepancy between the prevalence of those with and without SMI increased over time for most conditions. A greater increase in the mean number of additional conditions was observed in the SMI population over the study period (0.6 in 2000/2001 to 1.0 in 2011/2012) compared with those without SMI (0.5 in 2000/2001 to 0.6 in 2011/2012). For both groups, most conditions were more prevalent in more deprived areas, whereas for the SMI group conditions such as hypothyroidism, chronic kidney disease and cancer were more prevalent in more affluent areas. CONCLUSIONS: Our findings highlight the health inequalities faced by people with SMI. The provision of appropriate timely health prevention, promotion and monitoring activities to reduce these health inequalities are needed, especially in deprived areas

Primary care consultation rates among people with and without severe mental illness:a UK cohort study using the Clinical Practice Research Datalink

OBJECTIVES: Little is known about service utilisation by patients with severe mental illness (SMI) in UK primary care. We examined their consultation rate patterns and whether they were impacted by the introduction of the Quality and Outcomes Framework (QOF), in 2004. DESIGN: Retrospective cohort study using individual patient data collected from 2000 to 2012. SETTING: 627 general practices contributing to the Clinical Practice Research Datalink, a large UK primary care database. PARTICIPANTS: SMI cases (346 551) matched to 5 individuals without SMI (1 732 755) on age, gender and general practice. OUTCOME MEASURES: Consultation rates were calculated for both groups, across 3 types: face-to-face (primary outcome), telephone and other (not only consultations but including administrative tasks). Poisson regression analyses were used to identify predictors of consultation rates and calculate adjusted consultation rates. Interrupted time-series analysis was used to quantify the effect of the QOF. RESULTS: Over the study period, face-to-face consultations in primary care remained relatively stable in the matched control group (between 4.5 and 4.9 per annum) but increased for people with SMI (8.8-10.9). Women and older patients consulted more frequently in the SMI and the matched control groups, across all 3 consultation types. Following the introduction of the QOF, there was an increase in the annual trend of face-to-face consultation for people with SMI (average increase of 0.19 consultations per patient per year, 95% CI 0.02 to 0.36), which was not observed for the control group (estimates across groups statistically different, p=0.022). CONCLUSIONS: The introduction of the QOF was associated with increases in the frequency of monitoring and in the average number of reported comorbidities for patients with SMI. This suggests that the QOF scheme successfully incentivised practices to improve their monitoring of the mental and physical health of this group of patients

Resource Allocation during an Influenza Pandemic

Resource Allocation during an Influenza Pandemi

Personal Portable Computers and the Curriculum

First paragraph: Portable computers are, to all intents and purposes, smaller versions of the common ‘desktop' machine. Depending on their configuration, they can be as powerful as desktop machines but they have one major additional attribute. Instead of taking the work to the computer, the lightness and design of portables enables them to be carried to the place of work - to the school desk, to the library, on the field trip... Portable computers, therefore, hold out the promise of putting convenient and personalised computing power not just in pupils' hands but in teachers' hands too