Photon spectra in NPL standard monoenergetic neutron fields

A High Purity Germanium (HPGe) detector has been used to measure the photon spectra in the majority of monoenergetic neutron fields produced at NPL (0.144, 0.250, 0.565, 2.0, 5.0 and 16.5 MeV). The HPGe was characterised and then modelled to produce a response matrix. The measured pulse height spectra were then unfolded to produce photon fluence spectra. The new spectra were used to improve the photon to neutron dose equivalent ratios from some earlier work at NPL with Geiger-Muller tubes and electronic personal dosemeters.

Decision-Making Processes Related to Perseveration Are Indirectly Associated With Weight Status in Children Through Laboratory-Assessed Energy Intake

Decision-making contributes to what and how much we consume, and deficits in decision-making have been associated with increased weight status in children. Nevertheless, the relationships between cognitive and affective processes underlying decision-making (i.e., decision-making processes) and laboratory food intake are unclear. We used data from a four-session, within-subjects laboratory study to investigate the relationships between decision-making processes, food intake, and weight status in 70 children 7-to-11-years-old. Decision-making was assessed with the Hungry Donkey Task (HDT), a child-friendly task where children make selections with unknown reward outcomes. Food intake was measured with three paradigms: (1) a standard ad libitum meal, (2) an eating in the absence of hunger (EAH) protocol, and (3) a palatable buffet meal. Individual differences related to decision-making processes during the HDT were quantified with a reinforcement learning model. Path analyses were used to test whether decision-making processes that contribute to children’s (a) expected value of a choice and (b) tendency to perseverate (i.e., repeatedly make the same choice) were indirectly associated with weight status through their effects on intake (kcal). Results revealed that increases in the tendency to perseverate after a gain outcome were positively associated with intake at all three paradigms and indirectly associated with higher weight status through intake at both the standard and buffet meals. Increases in the tendency to perseverate after a loss outcome were positively associated with EAH, but only in children whose tendency to perseverate persistedacross trials. Results suggest that decision-making processes that shape children’s tendencies to repeat a behavior (i.e., perseverate) are related to laboratory energy intake across multiple eating paradigms. Children who are more likely to repeat a choice after a positive outcome have a tendency to eat more at laboratory meals. If this generalizes to contexts outside the laboratory, these children may be susceptible to obesity. By using a reinforcement learning model not previously applied to the study of eating behaviors, this study elucidated potential determinants of excess energy intake in children, which may be useful for the development of childhood obesity interventions.

Monitoring post-release behavioural activity of captive-bred urial (Ovis vignei punjabiensis) at Togh Managara Safari Park Khyber Pakhtunkhwa, Pakistan

The Punjab urial (Ovis vignei punjabiensis) is a globally threatened wild sheep species. In Pakistan the species is legally protected and bred in captivity to release into natural habitats to reinforce wild populations. Vigilance and feeding are critical to survival, though the degree to which captive-bred animals exhibit these behaviours post-release has rarely been investigated. We monitored the daily behaviours of five adult urial after release and classifying behaviours from 0600 hrs to 1800 hrs, replicating each one-hour period twice and recording four observations of each animal per hour. At the herd level, vigilance and feeding behaviours were exhibited equally. Males and females invested equal time in feeding, males were more vigilant (p = 0.001) and more aggressive (p = 0.010), and females were more restful (p = 0.019) or engaged in grooming (p = 0.044) or locomotion (p = 0.002). Females spent more time feeding than being vigilant (p = 0.002). Males maintained high levels of vigilance throughout the day. Patterns of resting 1300 hrs to 1500 hrs and feeding in early morning and late afternoon were common for both sexes. Behaviours classified as 'other' were exhibited equally between sexes. Our results reveal positive indications of captive-bred urial balancing threat detection and energy acquisition post-release and exhibiting natural behaviours and activity patterns. We encourage assessment of survivorship to evaluate long-term effectiveness of captive breeding and release as a candidate restoration programme.

Personality and psychopathology: In defense of a practical path toward integrating psychometric and biological approaches to advance a comprehensive model

Personality and psychopathology each reflect patterns of internal experience and outward behavior that differ between people and affect functioning. Drawing strict distinctions between the two concepts is not only difficult, but it may prove unnecessary for advancing an integrated model of psychological experiences associated with mental illness. We argue that developing such a model will be critical for improving treatment outcomes, and we discuss a practical path forward. Proponents of psychometric approaches to developing models of psychological experience focus on observable phenotypes and utilize statistical methods to describe patterns of covariation among a broad range of symptoms and dispositions. Advocates of biologically based approaches emphasize neuroscientific tools for identifying abnormalities in brain function that give rise to an individual's experience. There is substantial evidence that measures of personality and measures of symptoms capture nonoverlapping, clinically important information for understanding how and for whom treatments for mental illness work. In this article, we highlight the importance of combining psychometric and neurobiological approaches in order to understand which features of an individual those measures reflect, which aspects of neurobiology generate and maintain those features, how they relate to each other, and critically, how best to alter them to reduce distress and dysfunction.

Individual differences in the influence of taste and health impact successful dietary self-control: A mouse tracking food choice study in children

In order to improve dietary quality among children, there is a need to understand how they make decisions about what foods to eat. This study used a mouse tracking food choice task to better understand how attributes such as health and taste contribute to food decisions among 70 children aged 7-to-11 years old. Children rated health, taste, and desire to eat for 76 common foods that varied in energy density and then used a computer mouse to select which of two presented foods they would like to eat. The presented food pairs were based on children's own ratings of taste and health so that some trials required self-control to choose the healthier option (i.e., healthy/not tasty paired with unhealthy/tasty). Children's body mass index (BMI) percentile was not associated with number of healthy choices. To examine mouse trajectories, we replicated previous analytic techniques and applied a novel technique, time-varying effects modeling (TVEM). Results showed that desire to eat impacted food decision-making sooner than taste and health during trials that required self-control, with TVEM showing that early discounting of desire to eat enabled healthier choices. However, these temporal dynamics varied by age, BMI percentile, and overall self-control performance in the task. When the less healthy food was chosen (i.e., self-control failure), older children and children with better overall self-control were more influenced by taste and desire to eat. However, children with higher BMI percentiles showed stronger discounting (i.e., negative influence) of taste when choosing the healthier food. Together this highlights how the influence of hedonic food attributes on food decision-making varies by individual child-level characteristics. Understanding individual differences in the cognitive processes that support healthy food choices in children may help identify targets for interventions aimed at improving child nutrition.

Depicting corrosion-born defects in pipelines with combined neutron/γ ray backscatter: a biomimetic approach

The identification of corrosion, cracks and defects in pipelines used for transporting oil and gas can reduce the possibility of leaks, and consequently, it can limit the extent of an environmental disaster, public hazard and the associated financial impact of such events. Typically, corrosion in oil pipelines is measured with non-destructive ultrasonic or electromagnetic techniques, on the basis that corrosion and defects are often manifest as a change of thickness in the steel from which pipelines are made. However, such approaches are not practical for underground pipelines and their deployment can be complicated for the case of pipelines covered by insulation. In this paper, we present an innovative, non-destructive testing technique, which exploits the backscatter of a combination of fast-neutron and γ radiation from steel samples of a variety of thicknesses consistent with changes that might arise due to corrosion of a pipe wall. Our research demonstrates the potential to measure and characterise different steel thicknesses by detecting both the elastic, fast-neutron backscatter and the Compton-scattered γ radiations, simultaneously. Further, we demonstrate that the presence of insulation yields a consistent and separable influence on the experimental, wall-thickness measurements. The data from experimental measurements are supported by a comprehensive Monte Carlo computer simulation study.

Food or money? Children's brains respond differently to rewards regardless of weight status

BACKGROUND

Brain responses to both food and monetary rewards have been linked to weight gain and obesity in adults, suggesting that general sensitivity to reward contributes to overeating. However, the relationship between brain reward response and body weight in children is unclear.

OBJECTIVE

The objective of this study was to assess the brain's response to multiple rewards and the relationship to body weight in children.

METHODS

We tested this by performing functional magnetic resonance imaging while children (7- to 11-years-old; healthy weight [n = 31], overweight/obese [n = 30]) played a modified card-guessing task to assess blood-oxygen-level-dependent (BOLD) response to anticipating and winning food and money rewards. Functional magnetic resonance imaging data were analysed using a region of interest and exploratory whole-brain approach.

RESULTS

Region of interest results demonstrated increased BOLD response in the striatum to anticipating food vs. neutral (control) and winning money vs. neutral. Whole-brain data showed that winning money vs. food was associated with increased activation in the striatum, as well as regions associated with cognitive control and emotion. Notably, for both approaches, these effects were independent of child weight status. Additionally, children's reported food responsiveness and emotional overeating were negatively correlated with the BOLD response in the left cingulate gyrus for winning food vs. money.

CONCLUSION

Overall, findings from this study show that regions associated with reward, cognitive control and emotion may play a role in the brain's response to food and money rewards, independently of how much the child weighs. These findings provide insight into reward sensitivity in children, which may have implications for understanding overeating and the development of obesity.

A Novel Hierarchical LATER Process Model: Evaluating Latent Sources of Variation in Reaction Times of Adult Daily Smokers

Reaction time data from cognitive tasks continue to be a key way to assess decision-making in various contexts to better understand addiction. The goal of this paper is twofold: to introduce a nuanced modeling approach for reaction time data and to demonstrate the novel insights it can provide into the decision processes of nicotine-dependent individuals in different contexts. We focus on the Linear Approach to Threshold with Ergodic Rate (LATER) model, which is a cognitive process model that describes reaction time data in terms of two distinct aspects of cognitive functioning: speed of information accumulation ("accretion") and threshold amount of information needed prior to execution ("caution"). We introduce a novel hierarchical extension to the LATER model to simultaneously account for differences across persons and experimental conditions, both in the accretion and caution parameters. This approach allows for the inclusion of person-specific predictor variables to explain between-person variation in terms of accretion and caution together with condition-specific predictors to model experimental condition manipulations. To highlight the usefulness of this model, we analyze reaction time data from a study on adult daily cigarette smokers. Participants performed a monetary incentivized Go/No-Go task during two testing sessions, once while following their typical smoking patterns and again following 12 h of verified smoking abstinence. Our main results suggest that regardless of trial type, smokers in a period of abstinence have faster accretion rates, and lower caution thresholds relative to smoking as usual.

A systematic review of the content and delivery of education in pulmonary rehabilitation programmes

INTRODUCTION

Pulmonary rehabilitation (PR) is a core component of Chronic Obstructive Pulmonary Disease (COPD) management with well recognized benefits. While suggestions for educational content within pulmonary rehabilitation have been detailed in clinical guidance, it is unclear what educational content is delivered as part of pulmonary rehabilitation, who delivers it, and how it is delivered.

METHODS

A systematic review was conducted to identify what educational content is delivered as part of pulmonary rehabilitation, how is this delivered and who delivers it. Databases were searched from 1981 to 2017 using multiple search terms related to "pulmonary rehabilitation" and "education".

RESULTS

Fourteen studies were identified. This included 6 survey studies, 5 quasi-experimental studies and 3 RCTs. Five key topics that were consistently included within PR programmes were identified as: 1) Anxiety/depression and stress management. 2) Early recognition of signs of infection. 3) Dyspnea and symptom management. 4) Nutrition. 5) Techniques using inhalers and nebulizers. Broader topics such as welfare/benefits, sexuality, and advance care directives did not frequently feature. Only four studies used tools to measure knowledge or learning pre and post rehabilitation in an attempt to evaluate the effectiveness of the education delivered as part of PR.

CONCLUSIONS

The delivery of education in PR programmes is variable and does not follow suggested educational topics. Education needs to take a patient centered motivational approach to ensure effective delivery. Further research into appropriate educational outcome measures are needed, in order to evaluate the changes in behaviour associated with education.

Barriers and enablers to meticillin-resistant Staphylococcus aureus admission screening in hospitals: a mixed-methods study

BACKGROUND

To reduce the risk of transmission of meticillin-resistant Staphylococcus aureus (MRSA), international guidelines recommend admission screening to identify hospital patients at risk of colonization. However, routine monitoring indicates that optimum screening compliance levels are not always achieved. In order to enhance compliance, we must better understand those factors which influence staff screening behaviours.

AIM

To identify factors which influence staff compliance with hospital MRSA screening policies.

METHODS

A sequential two-stage mixed-methods design applied constructs from normalization process theory and the theoretical domains framework to guide data collection and analysis. Initial qualitative findings informed subsequent development of a national cross-sectional survey of nursing staff (N = 450). Multiple regression modelling identified which barriers and enablers best predict staff compliance.

FINDINGS

Three factors were significant in predicting optimum (>90%) compliance with MRSA screening: having MRSA screening routinized within the admission process; category of clinical area; feedback of MRSA screening compliance within the clinical area. Integration of data-sets indicated that organizational systems which 'make doing the right thing easy' influence compliance, as does local ward culture. Embedded values and beliefs regarding the relative (de)prioritization of MRSA screening are important.

CONCLUSION

To our knowledge, this is the first study to provide original evidence of barriers and enablers to MRSA screening, applying both sociological and psychological theory. As antimicrobial resistance is a global health concern, these findings have international relevance for screening programmes. Future policy recommendations or behaviour change interventions, based on the insights presented here, could have significant impact upon improving screening compliance.

ADDITIONAL CHARACTERISATION OF THE THERMAL NEUTRON PILE AT THE NATIONAL PHYSICAL LABORATORY, UK

As part of its wide-ranging neutron metrology capabilities, the National Physical Laboratory in the UK has a thermal neutron facility in which accelerator-produced neutrons are moderated within a large assembly or pile of graphite bricks. The neutron field has previously been well characterised in terms of the fluence rate and energy spectrum at various irradiation positions. However, recent changes to the structure (e.g. enlarging the central irradiation cavity) have prompted a renewal and extension of this work. We have also used Monte Carlo modelling to improve our understanding of the pile's performance.

PHOTON SPECTRA IN NPL STANDARD RADIONUCLIDE NEUTRON FIELDS

A HPGe detector has been used to measure the photon spectra from the majority of radionuclide neutron sources in use at NPL (252Cf, 241Am-Be, 241Am-Li, 241Am-B). The HPGe was characterised then modelled to produce a response matrix. The measured pulse height spectra were then unfolded to produce photon fluence spectra. Changes in the photon spectrum with time from a 252Cf source are evident. Spectra from a 2-year-old and 42-year-old 252Cf source are presented showing the change from a continuum to peaks from long-lived isotopes of Cf. Other radionuclide neutron source spectra are also presented and discussed. The new spectra were used to improve the photon to neutron dose equivalent ratios from some earlier work at NPL with GM tubes and EPDs.

Is brain response to food rewards related to overeating? A test of the reward surfeit model of overeating in children

The reward surfeit model of overeating suggests that heightened brain response to rewards contributes to overeating and subsequent weight gain. However, previous studies have not tested whether brain response to reward is associated with food intake, particularly during childhood, a period of dynamic development in reward and inhibitory control neurocircuitry. We conducted functional magnetic resonance imaging (fMRI) with 7-11-year-old children (n = 59; healthy weight, n = 31; overweight, n = 28; 54% female) while they played a modified card-guessing paradigm to examine blood-oxygen-level-dependent (BOLD) response to anticipating and winning rewards (food, money, neutral). Food intake was assessed at three separate meals that measured different facets of eating behavior: 1) typical consumption (baseline), 2) overindulgence (palatable buffet), and 3) eating in the absence of hunger (EAH). A priori regions of interest included regions implicated in both reward processing and inhibitory control. Multiple stepwise regressions were conducted to examine the relationship between intake and BOLD response to rewards. Corrected results showed that a greater BOLD response in the medial prefrontal cortex for anticipating food compared to money positively correlated with how much children ate at the baseline and palatable buffet meals. BOLD response in the dorsolateral prefrontal cortex for winning food compared to money was positively correlated with intake at the palatable buffet meal and EAH. All aforementioned relationships were independent of child weight status. Findings support the reward surfeit model by showing that increased brain response to food compared to money rewards positively correlates with laboratory measures of food intake in children.

Measuring patient activation: The utility of the Patient Activation Measure within a UK context-Results from four exemplar studies and potential future applications

OBJECTIVE

Patient activation can be measured using the Patient Activation Measure (PAM) developed by Hibbard et al., however, little is known about the uses of the PAM in research and in practice. This study aims to explore its differing utility in four UK exemplar sites.

METHODS

Data from four exemplars in a range of health settings with people living with long-term conditions (i.e. stroke or COPD) were evaluated. PAM scores were described and explored in relation to clinical and sociodemographic variables and outcome measures.

RESULTS

PAM scores illustrated that most with COPD or stroke reported PAM levels of 3 or 4, indicating that they are engaging, but may need help to sustain their scores. The exemplars illustrate the utility of, and potential issues involved in, using PAM as a process/outcome measure to predict activation and the effectiveness of interventions, and as a tool to inform tailoring of targeted interventions.

CONCLUSIONS

The PAM tool has been shown to be useful as an outcome measure, a screening tool to tailor education, or a quality indicator for delivery of care.

PRACTICE IMPLICATIONS

However good demographic and patient history are needed to substantiate PAM scores. Further work is needed to monitor PAM prospectively.

A Dual Vial Waveguide Exposure Facility for Examining Microwave Effects In Vitro

A waveguide exposure system operated between 2 and 4 GHz was assembled in a laboratory incubator in order to study potential temperature-dependent and temperature-independent actions of microwaves. Two vials containing cell cultures were exposed simultaneously in a single waveguide in order to reduce the space required, and to allow concurrent study of autologous cell cultures in two different functional states (resting and stimulated) during exposure. Dosimetry was performed using three techniques with different underlying assumptions, as well as the technique of differential power measurement. Each of the four techniques yielded different results, although differences between the two vials using any single technique were negligible. A significant 'hot spot' occurred at the center of each vial. The ratio between maximum and minimum absorption rate within a single vial was 33-fold using a vial of 1.2-cm diameter and 1.6-cm height. With agitation and exposure at specific absorption rate (SAR) equal to 21 mW/ml, the thermal gradient was less than 0.1 degrees C between these two points. The averaged SAR can be determined by steady-state heating analysis. The exposure system can be calibrated readily by calculation for the measured powers, but not by differential power measurement.

The diagnosis of COPD in primary care; gender differences and the role of spirometry

BACKGROUND

Females with exacerbations of Chronic Obstructive Pulmonary Disease now account for one half of all hospital admissions for that condition and rates have been increasing over the last few decades. Differences in presentations of disease between genders have been shown in several conditions and this study explores whether there are inter gender biases in probable diagnoses in those suspected to have COPD.

METHODS

445 individuals with a provisional diagnosis by their General Practitioner of "suspected COPD" or "definite COPD" were referred to a community Respiratory Assessment unit (CRAU) for tests including spirometry. Gender, demographics, respiratory symptoms and respiratory medical history were recorded. The provisional diagnoses were compared with the final diagnosis made after spirometry and respiratory specialist nurse review and the provisional diagnosis was either confirmed as correct or refuted as unlikely.

RESULTS

Significantly more men (87.5%) had their diagnosis of "definite COPD" confirmed compared to 73.9% of women (p = 0.021). When the GP suggested a provisional diagnosis of "suspected COPD" (n = 265) at referral, this was confirmed in 60.9% of men and only 43.2% of women (p = 0.004). There was a different symptom pattern between genders with women being more likely to report allergies, symptoms starting earlier in life, and being less likely than men to report breathlessness as the main symptom.

CONCLUSIONS

These results may suggest a difference between genders in some of the clinical features of COPD and a difference in likelihood of a GPs provisional diagnosis of COPD being correct. The study reiterates the absolute importance of spirometry in the diagnosis of COPD.

Reduced Influence of Monetary Incentives on Go/NoGo Performance During Smoking Abstinence

INTRODUCTION

Smokers may experience decreased sensitivity to nondrug incentives during acute smoking deprivation. This decreased sensitivity may undermine attempts to encourage continued abstinence by enhancing cognitive processes through the use of monetary incentives. This study assessed whether the capacity for monetary incentives to enhance cognitive performance was compromised in nicotine-deprived smokers.

METHOD

Eighteen smokers performed an incentivized Go/NoGo task on 2 occasions, once after smoking as usual prior to the session, and once after undergoing 12-hr abstinence. Participants could earn up to $5.00 ($2.50 per session) based on their performance on reward blocks of the Go/NoGo task.

RESULTS

Performance was significantly more accurate on incentivized NoGo, frequent-Go, and infrequent-Go trials relative to neutral trials during the smoke as usual session. Participants also produced fewer premature, impulsive responses on rewarded versus neutral blocks during the smoke as usual session. No significant difference between reward and neutral blocks was observed on any of the 4 performance indices during the abstinent session.

CONCLUSIONS

The ability for monetary incentives to enhance inhibitory control may be compromised during acute abstinence in smokers. These findings may have implications for contingency management treatment programs which are thought to promote continued abstinence partly by facilitating the allocation of cognitive resources to processes that encourage continued abstinence by increasing the value associated with continued abstinence.

Bonner sphere measurements of 241Am-B and 241Am-F neutron energy spectra unfolded using high-resolution a priori data

High-resolution neutron energy spectra, covering the entire energy range of interest, for two standard radionuclide neutron sources ((241)Am-B and (241)Am-F) have been derived from Bonner sphere measurements by using high-resolution a priori data in the unfolding process. In each case, two a priori spectra were used, one from a two-stage calculation and also one from a combination of the calculated spectrum with a high-resolution measured spectrum. The unfolded spectra are compared with those published elsewhere and show significant differences from the ISO- and IAEA-recommended spectra for (241)Am-B and (241)Am-F, respectively. Values for the fluence-average energy and fluence-to-dose-equivalent conversion coefficients are presented for the new spectra, and the implications of the new spectra for the emission rates of the sources when measured by the manganese bath technique are also determined.

Correction and verification of AECL Bonner Sphere response matrix based on mono-energetic neutron calibration performed at NPL

The AECL Bonner Sphere Spectrometer (BSS) was taken to National Physical Laboratory (NPL) for calibration in mono-energetic neutron fields and bare (252)Cf neutron fields. The mono-energetic radiations were performed using ISO-8529 prescribed neutron energies: 0.071, 0.144, 0.565, 1.2, 5 and 17 MeV. A central SP9 proportional counter was also evaluated at the NPL thermal neutron calibration facility in order to assess an effective pressure of (3)He inside the counter, i.e. number density of (3)He atoms. Based on these measurements and methods outlined by Thomas and Soochak, a new BSS response matrix was generated. The response matrix is then verified by unfolding spectra corresponding to various neutron fields. Those are NPL bare (252)Cf source, National Institute of Standards and Technology bare and heavy water moderated (252)Cf source and (241)AmBe calibration source located at National Research Council. A good agreement was observed with expected neutron fluence rates, as well as derived dosimetric quantities, such as International Commission on Radiological Protection-74 ambient dose equivalent.

Photon doses in NPL standard neutron fields

Standard neutron fields are invariably accompanied by a photon component due to the neutron-generating reactions and secondary neutron interactions in the surrounding environment. A set of energy-compensated Geiger-Müller (GM) tubes and electronic personal dosemeters (EPDs) have been used to measure the photon dose rates in a number of standard radionuclide and accelerator-based neutron fields. The GM tubes were first characterised in standard radioisotope and X-ray photon fields and then modelled using MCNP to determine their photon dose response as a function of energy. Values for the photon-to-neutron dose equivalent ratios are presented and compared with other published values.

Digital dual-parameter data acquisition for SP2 hydrogen-filled proportional counters

Hydrogen-filled proportional counters perform well as neutron spectrometers in the energy region from a few tens of keV up to ∼1.5 MeV. Unfortunately, gamma rays also generate signals in these detectors. It is possible in principle to distinguish the two types of event via the rise time of their respective signal pulses, but the data acquisition system needed for this is complex to assemble and adjust if one uses conventional modular analogue electronics. In this work a digital sampling system, in conjunction with custom software, was used to measure and acquire amplitude and rise time data from type SP2 counters. The interpretation of the data was supported by a Monte Carlo calculation. The performance of the system is compared with that of a conventional 1-parameter analogue system, and the potential of the digital technique to supplant conventional methods is discussed.

Preclinic telephone consultations: an observational cohort study

Patients referred to secondary care for specialist respiratory review frequently undergo multiple hospital attendances for investigations and consultations. This study evaluated the potential of a preclinic telephone consultation and subsequent coordination of tests and face-to-face consultations to reduce hospital visits. Total hospital attendances were recorded for three cohorts (participants, non-participants and comparators) for 6 months from first specialist contact. Patients completed the medical interview satisfaction scale-21 (MISS-21). The study showed that a preclinic telephone consultation can significantly reduce hospital visits over a fixed period without reducing patient satisfaction. In total, 20.8% of the participant group had three or more hospital attendances compared with 42.9% of the non-participant group (p = 0.001) and 44.7% of the comparator group (p = 0.002). Participants had fewer follow up visits and lower rates of non-attendance/late rearrangement of appointments. This service reduces unnecessary hospital visits, seems to improve patient compliance and may save costs associated with non-attendance and follow up consultations.

Barriers to the implementation of self management support in long term lung conditions

Background Self-management improves outcomes in asthma and COPD and is strongly recommended in national and international guidelines; however implementation of the guidelines such as use of written action plans in practice is often poor. Setting A questionnaire survey was undertaken to identify the healthcare professional barriers to implementation of self-management for asthma and COPD in West London. Question Why is self-management education not being undertaken in respiratory conditions? Methods A questionnaire was designed to elicit healthcare professionals' views about barriers to implementation of self-management in asthma and COPD. Results Response rates were 33% (58/175). Results showed strong support for guideline recommendations, however implementation was patchy. Seventy six percent of respondents discussed asthma self-management with patients; however only 47.8% of patients received a written action plan. For COPD patients, 55.1% discussed self-management, with 41% receiving a written action plan. In COPD, there was greater GP involvement and less delegation of self-management. Barriers to implementation included patient factors (compliance, literacy and patient understanding), time constraints and insufficient resources. Those who believed they had witnessed improved health outcomes with self-management (53%, 31/58) were more likely to give written action plans (78%, 24/31, 'nearly always/sometimes' gave written action plans), Nearly a third of healthcare professionals reported lacking confidence in constructing written action plans (33% 19/58; GPs 43%, nurses 43%). Conclusion Despite overwhelming evidence self-management support is still not being implemented into routine clinical practice, identified barriers included time constraints, lack of training, lack of belief in patients ability to self-manage and lack of confidence completing self-management plans. Practice implications These issues need to be addressed if self-management support is to be delivered in a meaningful and effective way.

Evaluation of a paper and electronic pictorial COPD action plan

Personalised written action plans are increasingly regarded as an important component of chronic obstructive pulmonary disease (COPD) self-management support and yet they may not be understood by those with limited literacy skills. This study was designed to produce a comprehensible pictorial COPD action plan for use by patients and health care professionals. With advice from a group of doctors and nurses a 'standard' written COPD action plan was translated by a medical artist into a series of pictorial images. These were assessed using the techniques of guessability and translucency in 21 adults attending a COPD clinic in a London hospital. Guessability and translucency scores show that pictograms were reasonably well understood, with only 3 pictograms showing low score in both guessability and translucency questionnaires. These included images depicting increased sputum production, swollen ankles, and use of extra doses of reliever medication. However, after brief spoken reinforcement about self-management, most patients could use the pictorial plan to suggest appropriate self-management behaviour such as when to access medical care. We have developed a pictorial COPD action plan. Pictorial methods represent an effective method of reinforcing the spoken word for all ranges of literacy.

Are evaluated respiratory service developments implemented into clinical practice?

INTRODUCTION

Evaluation of the way in which respiratory care is delivered is increasingly recognised to be an important area for research. When service developments are reported, it is not always clear whether they are subsequently implemented within the reporting institution, and if not why not.

METHODS

3281 abstracts from three specialist journals and one general journal were reviewed, and 36 reported evaluated service developments identified. The authors of each of these were approached to determine whether the reported service developments were in use in their institution.

RESULTS

30 of the 36 authors responded (83%). 10 reports were of sharing care with nurses and five with other health professionals, and the remainder involved new technologies, education, patient information or guideline implementation. 15/30 had implemented the reported development into practice, 11 of which were implemented immediately. Delays were due to staffing, funding and organisational issues. 10/15 studies were not put into practice, the main reason being that the key person had left. Four respondents embarked upon further study to confirm their preliminary published findings.

CONCLUSIONS

Reports of apparently positive service developments are only implemented in approximately one-half of institutions reporting the development. In a third of cases, non-implementation reflects the original authors believing that further study is necessary to confirm effectiveness.

Recent developments in radionuclide neutron source emission rate measurements at the National Physical Laboratory

This paper outlines the key features of the new manganese bath facility of the National Physical Laboratory and describes the measurements performed to characterise and validate the facility. Other developments have focused on the use of MCNP to calculate the fraction of neutrons captured by nuclei other than manganese and the fraction escaping from the bath. This has highlighted the large difference in the oxygen(n,alpha) capture fraction when different cross-section evaluations are applied. This can change the value obtained for the neutron emission rate of a source by up to 0.8%.

A nurse led intermediate care package in patients who have been hospitalised with an acute exacerbation of chronic obstructive pulmonary disease

OBJECTIVES

To determine the effects of a nurse led intermediate care programme in patients who have been hospitalised with an acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

DESIGN

Randomised controlled trial.

SETTING

Community and hospital care in west London.

PARTICIPANTS

122 patients with COPD.

INTERVENTION

A care package incorporating initial pulmonary rehabilitation and self-management education, provision of a written, personalised COPD action plan, monthly telephone calls and 3 monthly home visits by a specialist nurse for a period of 2 years.

MAIN OUTCOME MEASURE

Hospital readmission rate.

SECONDARY OUTCOMES

Unscheduled primary care consultations and quality of life.

RESULTS

There were no differences in hospital admission rates or in exacerbation rates between the two groups. Self-management of exacerbations was significantly different and the intervention group were more likely to be treated with oral steroids alone or oral steroids and antibiotics, and the initiators of treatment for exacerbations were statistically more likely to be the patients themselves. 12 patients in the control group died during the 2 year period, eight as a result of COPD, compared with six patients in the intervention group, of whom one died from COPD. This is a significant difference. When the numbers were adjusted to reflect the numbers still alive at 2 years, in the intervention group patients reported a total of 171 unscheduled contacts with their general practitioner (GP) and in the control group, 280 contacts. The number needed to treat was 0.558--ie, for every one COPD patient receiving the intervention and self-management advice, there were 1.79 fewer unscheduled contacts with the GP.

CONCLUSIONS

An intermediate care package incorporating pulmonary rehabilitation, self-management education and the receipt of a written COPD action plan, together with regular nurse contact, is associated with a reduced need for unscheduled primary care consultations and a reduction in deaths due to COPD but did not affect the hospital readmission rate.

Characterization and utilization of a Bonner sphere set based on gold activation foils

Bonner sphere (BS) sets which use activation foils as the central thermal neutron sensor have advantages over active BS systems in certain environments, for example, pulsed fields, or fields with high photon components. In such environments, they may be the only type of neutron spectrometer which can be used. This paper describes work, using both measurements and calculations, to validate the response functions for a BS set based on gold activation foils. As an illustration of the use of such a system, a measurement is described of the contaminant neutron spectrum in the treatment room of a 21 MV hospital linear accelerator providing photon beams for radiotherapy.

Investigation of combined unfolding of neutron spectra using the UMG unfolding codes

An investigation of the simultaneous unfolding of data from neutron spectrometers using the UMG codes MAXED and GRAVEL has been performed. This approach involves combining the data from the spectrometers before unfolding, thereby performing a single combined unfolding of all the data to yield a final combined spectrum. The study used measured data from three proton recoil counters and also Bonner sphere and proton recoil counter responses calculated from their response functions. In each case, the spectrum derived from combined unfolding is compared with either the spectrum obtained from merging the independently unfolded spectra or the spectrum used to calculate the responses. The advantages and disadvantages of this technique are discussed.

The content of 250Cf and 248Cm in 252Cf neutron sources and the effect on the neutron emission rate

One of the most common radionuclide neutron sources used for the calibration of detectors is (252)Cf. However, these sources also contain (250)Cf, which is present in the material from which the sources are made, and (248)Cm, which is formed as the daughter of (252)Cf via alpha-decay. Both decay by spontaneous fission with longer half-lives than (252)Cf. Consequently, as the source becomes older, the emission rate does not follow the decay curve of (252)Cf. Fits have been made to emission rate measurements of (252)Cf sources at NPL spanning over 30 y to deduce their (250)Cf and (248)Cm content. The emission rate of a source can be significantly underestimated if the presence of (250)Cf and (248)Cm is not taken into account, and this has been investigated for a typical (252)Cf source. The importance of this problem to other calibration laboratories and users of (252)Cf sources is emphasised.

How is difficult asthma managed?

Most patients with asthma can be easily treated. Some have difficult asthma; in some because the diagnosis is erroneous, in others because of comorbidity or noncompliance. A European Respiratory Society Task Force has called for an integrated approach for these patients, and positive results have been reported using protocols. In the UK, there is no overall understanding of the size of this problem, or how these patients are managed. A postal survey of 683 consultant members of the British Thoracic Society designed to elicit respondents' views on how they would manage four clinical scenarios was conducted. There was a 50.4% response rate. Few reported a uniform approach to the investigation of such patients. The availability of allied healthcare professionals was variable. The 21 consultant respiratory physicans, reporting a special interest in difficult asthma, were significantly more likely to objectively assess compliance, perform skin-prick tests and to utilise a liaison psychiatrist than those without an expressed special interest in asthma. Many reported difficulty in accessing psychologists, liaison psychiatrists and social workers. Approaches to the diagnosis and management of "vocal cord dysfunction" were variable. The results of this postal survey of specialist thoracic physicians in the UK suggest that a protocol for difficult asthma is not in widespread use and that access to necessary allied healthcare professionals is not uniform. Pulmonologists with a declared special interest in difficult asthma may have configured their services and approaches more in line with that proposed by the European Respiratory Society Task Force.

Modelling of neutron survey instrument performance and experimental validation of those calculated response data

Three moderator-type neutron survey instruments have been modelled for energy and angle dependence of the response, in greater detail than before. These response data have been verified by comparison with published experimental measurements and measurements made specifically for this project. Influences on the instrument response have also been investigated. These have included its mode-of-use and perturbations caused by variations in the instrument manufacture. The implications of these new response data have been assessed by an extensive programme of folding the responses with workplace energy distributions.

Characterisation of the IRSN CANEL/T400 facility producing realistic neutron fields for calibration and test purposes

The new CANEL/T400 facility has been set-up at the Institute for Radiological Protection and Nuclear Safety (IRSN) to produce a realistic neutron field. The accurate characterisation of this neutron field is mandatory since this facility will be used as a reference neutron source. For this reason an international measuring campaign, involving four laboratories with extensive expertise in neutron metrology and spectrometry, was organised through a concerted EUROMET project. Measurements were performed with Bonner sphere (BS) systems to determine the energy distribution of the emitted neutrons over the whole energy range (from thermal energy up to a few MeV). Additional measurements were performed with proton recoil detectors to provide detailed information in the energy region above 90 keV. The results obtained by the four laboratories are in agreement with each other and are compared with a calculation performed with the MCNP4C Monte-Carlo code. As a conclusion of this exercise, a reliable characterisation of the CANEL/T400 neutron field is obtained.

Angle dependence of response characteristics of neutron survey instruments

Neutron area survey instruments are designed to have an approximately isotropic response. In practice, the response cannot be perfectly isotropic for instruments that do not have spherical symmetry, and for all instruments it is modified by the inclusion of batteries, electronics, handles, etc. This affects the ability of the survey instrument to measure accurately an isotropic dose equivalent quantity. Measurements of the angle dependence of response for four of the most commonly used designs of survey instrument (Harwell 0949, Mark 7 NRM, NM2 and Studsvik 2202D) have been performed in a low-scatter room using radionuclide and monoenergetic neutron sources. The Monte Carlo code MCNP has been used to model the responses and to investigate their sensitivity to the polyethylene density, counting gas pressure and other manufacturing tolerances. Preliminary modelling results are presented here.

Practical implications of neutron survey instrument performance

Improvements have been made to the Monte Carlo modelling used to calculate the response of the neutron survey instruments most commonly used in the UK, for neutron energies up to 20 MeV. The improved modelling of the devices includes the electronics and battery pack, allowing better calculations of both the energy and angle dependence of response. These data are used to calculate the response of the instruments in rotationally and fully isotropic, as well as unidirectional fields. Experimental measurements with radionuclide sources and monoenergetic neutron fields have been, and continue to be made, to test the calculated response characteristics. The enhancements to the calculations have involved simulation of the sensitivity of the response to variations in instrument manufacture, and will include the influence of the user and floor during measurements. The practical implications of the energy and angle dependence of response, variations in manufacture, and the influence of the user are assessed by folding the response characteristics with workplace energy and direction distributions.

Airway epithelial inflammatory responses and clinical parameters in COPD

This study examined inflammatory responses from primary cultured human bronchial epithelial cells in chronic obstructive pulmonary disease (COPD) and the clinical factors modulating them. Epithelial cells from bronchoscopic biopsies from 14 patients with COPD ((mean +/- SD) age 74.6 +/- 5.7 yrs, forced expiratory volume in one second (FEV1) 1.21 +/- 0.36 L, FEV1 %, predicted 51.1 +/- 15.8%, 51.5 +/- 24.0 pack-yrs of smoking, inhaled steroid dosage 1237.5 +/- 671.0 microg x day(-1), Medical Research Council (MRC) dyspnoea score 3.18 +/- 1.33) and eight current/exsmokers with normal pulmonary function (age 60.4 +/- 13.5 yrs, FEV1 2.66 +/- 1.27 L, FEV1 % pred 89.6 +/- 17.7%, 49 +/- 44 pack-yrs of smoking, MRC dyspnoea score 1 +/- 0) were grown in primary culture and exposed to 50 ng x mL(-1) tumour necrosis factor-alpha. Stimulated COPD cells produced significantly more interleukin (IL)-6 at 24 and 48 h, and IL-8 at 6 and 24 h than unstimulated COPD cells. This response was not seen in cells from current/exsmokers. IL-6 and IL-8 production was lower in COPD patients taking inhaled steroids. Following an inflammatory stimulus, bronchial epithelial cells in chronic obstructive pulmonary disease show a significant cytokine response not seen in smokers with normal pulmonary function and this may be modified by inhaled steroid therapy.

Human lymphocyte apoptosis after exposure to influenza A virus

Infection of humans with influenza A virus (IAV) results in a severe transient leukopenia. The goal of these studies was to analyze possible mechanisms behind this IAV-induced leukopenia with emphasis on the potential induction of apoptosis of lymphocytes by the virus. Analysis of lymphocyte subpopulations after exposure to IAV showed that a portion of CD3(+), CD4(+), CD8(+), and CD19(+) lymphocytes became apoptotic (terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling positive). The percentage of cells that are infected was shown to be less than the percentage of apoptotic cells, suggesting that direct effects of cell infection by the virus cannot account fully for the high level of cell death. Removal of monocytes-macrophages after IAV exposure reduced the percent of lymphocytes that were apoptotic. Treatment of virus-exposed cultures with anti-tumor necrosis factor alpha did not reduce the percentage of lymphocytes that were apoptotic. In virus-exposed cultures treated with anti-FasL antibody, recombinant soluble human Fas, Ac-DEVD-CHO (caspase-3 inhibitor), or Z-VAD-FMK (general caspase inhibitor), apoptosis and production of the active form of caspase-3 was reduced. The apoptotic cells were Fas-high-density cells while the nonapoptotic cells expressed a low density of Fas. The present studies showed that Fas-FasL signaling plays a major role in the induction of apoptosis in lymphocytes after exposure to IAV. Since the host response to influenza virus commonly results in recovery from the infection, with residual disease uncommon, lymphocyte apoptosis likely represents a part of an overall beneficial immune response but could be a possible mechanism of disease pathogenesis.

Detection of rare mutant alleles by restriction endonuclease-mediated selective-PCR: assay design and optimization

BACKGROUND

Restriction endonuclease-mediated selective (REMS)-PCR, allows detection of point mutations, deletions, and insertions. Reactions require concurrent activity of a restriction endonuclease (RE) and a DNA polymerase, both of which must be sufficiently thermostable to retain activity during thermocycling. The inclusion of the RE in REMS-PCR inhibits amplification of sequences containing the RE recognition site, thus producing selective amplification of sequences that lack the RE site.

METHODS

Assays were used that allowed the selection of conditions that produce concurrent RE/DNA polymerase activity. The RE thermostability assay involved thermocycling a RE under various conditions and assessing residual cleavage activity at various time points. Conditions found to preserve RE activity during thermocyling were then tested for their compatibility with DNA polymerase-mediated PCR.

RESULTS

A range of conditions that preserve activity of the RE BstNI over 30 cycles of PCR was identified. A subset of these conditions was subsequently found to mediate specific amplification using Taq DNA polymerase. These conditions were used to develop a REMS-PCR protocol for the detection of mutations at codon 12 of the K-ras gene. This protocol allowed the detection of 1 mutant allele in a background of 1000 wild-type alleles. The presence of primer sets for RE and PCR control amplicons provided unambiguous assessment of mutant status.

CONCLUSION

Implementation of the assays described may facilitate development of REMS-PCR assays targeted to other loci associated with disease.

Supportive management in bacterial meningitis

The central nervous system and systemic complications of bacterial meningitis cause significant morbidity and mortality. This article offers insight into the clinical features, pathogenesis, and management of these complications. In many instances, the improved outcome of intervention is based on clinical suspicion and early recognition. The management of complications is evolving and is presently based mainly on supportive care.

A Nod factor-binding lectin is a member of a distinct class of apyrases that may be unique to the legumes

Recent studies from our laboratory have found that a root lectin from the legume Dolichos hifloris is present on the root surface, binds rhizobial Nod factor and has apyrase activity. To assess the broader significance of this lectin/nucleotide phosphohydrolase (Db-LNP), we have cloned a second related cDNA (Db-apyrase-2) from D. hiflorus, as well as related cDNAs from the legumes Lotus japonicus and Medicago sativa, and from Arabidopsis thaliana, a non-legume. The deduced amino acid sequences of these apyrases were aligned with one another and with the sequences of other apyrases from plants, animals, yeast and protozoa. Phylogenetic analysis shows that Db-LNP has closely related orthologs only in other legumes, while Db-apyrase-2 is more closely related to apyrase sequences from non-leguminous plants. We also show that the orthologs of Db-LNP from M. sativa and Pisum sativum have carbohydrate binding activity. The results suggest that legume LNPs may represent a special class of apyrases that arose by gene duplication and subsequent specialization.

A nod factor binding lectin with apyrase activity from legume roots

A lectin isolated from the roots of the legume, Dolichos biflorus, binds to Nod factors produced by rhizobial strains that nodulate this plant and has a deduced amino acid sequence with no significant homology to any lectin reported to date. This lectin also is an enzyme that catalyzes the hydrolysis of phosphoanhydride bonds of nucleoside di- and triphosphates; the enzyme activity is increased in the presence of carbohydrate ligands. This lectin-nucleotide phosphohydrolase (LNP) has a substrate specificity characteristic of the apyrase category of phosphohydrolases, and its sequence contains four motifs characteristic of this category of enzymes. LNP is present on the surface of the root hairs, and treatment of roots with antiserum to LNP inhibits their ability to undergo root hair deformation and to form nodules on exposure to rhizobia. These properties suggest that this protein may play a role in the rhizobium-legume symbiosis and/or in a related carbohydrate recognition event endogenous to the plant.

QacR is a repressor protein that regulates expression of the Staphylococcus aureus multidrug efflux pump QacA

The Staphylococcus aureus QacA protein is a multidrug transporter that confers resistance to a broad range of antimicrobial agents via proton motive force-dependent efflux of the compounds. Primer extension analysis was performed to map the transcription start points of the qacA and divergently transcribed qacR mRNAs. Each gene utilized a single promoter element, the locations of which were confirmed by site-directed mutagenesis. Fusions of the qacA and qacR promoters to a chloramphenicol acetyl transferase reporter gene were used to demonstrate that QacR is a trans-acting repressor of qacA transcription that does not autoregulate its own expression. An inverted repeat overlapping the qacA transcription start site was shown to be the operator sequence for control of qacA gene expression. Removal of one half of the operator prevented QacR-mediated repression of the qacA promoter. Purified QacR protein bound specifically to this operator sequence in DNase I-footprinting experiments. Importantly, addition of diverse QacA substrates was shown to induce qacA expression in vivo, as well as inhibit binding of QacR to operator DNA in vitro, by using gel-mobility shift assays. QacR therefore appears to interact directly with structurally dissimilar inducing compounds that are substrates of the QacA multidrug efflux pump.

Genetic evaluation of suspected cases of transient HIV-1 infection of infants

Detection of human immunodeficiency virus-type 1 (HIV-1) on only one or a few occasions in infants born to infected mothers has been interpreted to indicate that infection may be transient rather than persistent. Forty-two cases of suspected transient HIV-1 viremia among 1562 perinatally exposed seroreverting infants and one mother were reanalyzed. HIV-1 env sequences were not found in specimens from 20; in specimens from 6, somatic genetic analysis revealed that specimens were mistakenly attributed to an infant; and in specimens from 17, phylogenetic analysis failed to demonstrate the expected linkage between the infant's and the mother's virus. These findings argue that transient HIV-1 infection, if it exists, will only rarely be satisfactorily documented.