586 research outputs found
Phosphorus sorption, supply potential and availability in soils with contrasting parent material and soil chemical properties
Soil phosphorus (P) management requires a more targeted and soil-specific approach than is currently applied for agronomic recommendations and environmental evaluation. Phosphorus buffering capacities control the supply of P in the soil solution and were measured across Irish soils with contrasting parent material and chemical properties. Langmuir sorption buffer capacities (MBCs) and binding energies (b) were strongly correlated with soil pH and extractable aluminium (Al). A broken-line regression fitted to the relationship between MBC and Al derived a change-point value for Al above which MBC increased linearly. Soils above the change point were predominantly acidic to neutral with non-calcareous parent material, with larger buffering capacities and binding energies than calcareous soils. Ratios of Mehlich3-Al and P (Al:P) were used to relate buffering capacity to supply potential in non-calcareous soils. Large ratios of Al:P were associated with poor P availability, characteristic of strongly P-fixing soils. Threshold values of iron-oxide paper strip P (FeO-P) and Morgan's P revealed Al:P ratios where soils began to supply P in available form. The change-point for Morgan's P fell within the current target index for P availability; however, the confidence interval was more compatible with previous agronomic P indices used in Ireland. Relationships between Morgan's P and measures of extractable P, M3-P and Olsen P, deviated in calcareous soils at large soil P contents, indicative of P precipitation processes dominating in these soils. Identifying differences in soil P buffering capacity at the laboratory scale would improve agronomic and environmental assessment at field and catchment scales
Sleep regularity and predictors of sleep efficiency and sleep duration in elite team sport athletes
Background
Many elite athletes have suboptimal sleep duration and efficiency, potentially due to factors that may impact sleep onset and offset times. Variability in sleep onset and offset may negatively influence sleep. The sleep regularity index (SRI) is a novel metric for sleep regularity, however there are no published descriptions of SRI in elite athletes. Further, contributors to sleep efficiency and duration in elite athletes using objective measures have not been explored.
Methods
Sleep was monitored over a minimum of seven consecutive days (7 to 43)—in 203 elite team sport athletes (age range = 19–36 years; female, n = 79; male, n = 124, total sleep nights = 1975) using activity monitoring and sleep diaries. The sleep regularity index (SRI) was calculated to reflect the night-to-night shifts in sleep by accounting for changes in sleep onset and sleep offset. Sleep characteristics were compared between regular and irregular sleepers and important contributors to sleep efficiency and total sleep time were assessed using multiple linear regression models.
Results
The median sleep regularity index and interquartile range were 85.1 (81.4 to 88.8). When compared to irregular sleepers, regular sleepers demonstrated (1) significantly greater sleep efficiency (p = 0.006; 0.31 medium effect size [ES]), (2) significantly less variability in total sleep time (− p ≤ 0.001; − 0.69, large ES) and sleep efficiency (− 0.34, small ES), (3) similar total sleep time and (4) significantly less variation in sleep onset (p ≤ 0.001; − 0.73, large ES) and offset (p ≤ 0.001; − 0.74, large ES) times. Sleep characteristics explained 73% and 22% of the variance in total sleep time and sleep efficiency, respectively. The most important contributor to total sleep time was a later sleep offset time, while the most important contributors to sleep efficiency were an earlier bedtime and less variable sleep onset times.
Conclusions
Bedtime and a consistent sleep onset time are important factors associated with sleep efficiency in athletes, while sleep offset is an important factor for total sleep time. Coaches and staff can assist their athletes by providing training schedules that allow for both regularity and sufficiency of time in bed where possible
Exploring the effects of BCG vaccination in patients diagnosed with tuberculosis: Observational study using the Enhanced Tuberculosis Surveillance system.
BACKGROUND: Bacillus Calmette-Guérin (BCG) is one of the most widely-used vaccines worldwide. BCG primarily reduces the progression from infection to disease, however there is evidence that BCG may provide additional benefits. We aimed to investigate whether there is evidence in routinely-collected surveillance data that BCG vaccination impacts outcomes for tuberculosis (TB) cases in England. METHODS: We obtained all TB notifications for 2009-2015 in England from the Enhanced Tuberculosis surveillance system. We considered five outcomes: All-cause mortality, death due to TB (in those who died), recurrent TB, pulmonary disease, and sputum smear status. We used logistic regression, with complete case analysis, to investigate each outcome with BCG vaccination, years since vaccination and age at vaccination, adjusting for potential confounders. All analyses were repeated using multiply imputed data. RESULTS: We found evidence of an association between BCG vaccination and reduced all-cause mortality (aOR:0.76 (95%CI 0.64-0.89), P:0.001) and weak evidence of an association with reduced recurrent TB (aOR:0.90 (95%CI 0.81-1.00), P:0.056). Analyses using multiple imputation suggested that the benefits of vaccination for all-cause mortality were reduced after 10 years. CONCLUSIONS: We found that BCG vaccination was associated with reduced all-cause mortality in people with TB although this benefit was less pronounced more than 10 years after vaccination. There was weak evidence of an association with reduced recurrent TB
Open-resorcinarenes, a new family of multivalent scaffolds
A new family of multivalent ligand platforms, the open-resorcinarenes, has been prepared in a straightforward two-step reaction. Modification of the core gives a range of topologically diverse scaffolds; functionalisation confirms the versatility of this approach, as shown through the formation of an octacalixarene array
Orthotic management of instability of the knee related to neuromuscular and central nervous system disorders: qualitative interview study of patient perspectives
Objectives: Adults with knee instability related to neuromuscular disorders or central nervous conditions often experience mobility problems and rely on orthoses to improve function and mobility. Patient views of device effectiveness and acceptability are underexplored. Our study aimed to elicit device users’ perspectives regarding fitting, acceptability, effectiveness and use of orthoses, and identify important treatment outcomes. /
Design: Qualitative descriptive study using in-depth semistructured interviews. Interview transcriptions were coded and thematically analysed, using ‘Framework’. /
Setting and participants: A purposive sample of 24 adult users of orthotic devices. Nineteen patients were recruited across three National Health Service sites, and five people through charities/patient support groups in England. Half of the participants had been diagnosed with poliomyelitis, and the remainder with multiple sclerosis, Charcot-Marie-Tooth disease, spinal injury or spina bifida, and stroke. The median age of participants was 64.5 years (range 36–80 years). /
Results: Patients’ medical condition impacted significantly on daily life. Participants relied on orthotic devices to enable engagement in daily activities. Patient goals for mobility were linked to individual circumstances. Desired treatment outcomes included reduction in pain, trips and falls, with improved balance and stability. Effectiveness, reliability, comfort and durability were the most valued features of orthoses and associated with reported use. Obtaining suitable footwear alongside orthotic devices was a significant concern. Time pressures during device fitting were viewed negatively. /
Conclusions: Orthotic devices for knee instability play a crucial role in promoting, maintaining and enhancing physical and psychological health and well-being, enabling patients to work, engage in family life and enjoy social activities. Future research should consider how best to measure the impact of orthotic devices on patient quality of life and daily functioning outside the clinic setting, as well as device use and any adverse effects. /
Trial registration number: This qualitative study was retrospectively registered as Current Controlled Trials ISRCTN65240228
Differences between naive and memory T cell phenotype in Malawian and UK adolescents: a role for Cytomegalovirus?
Background: Differences in degree of environmental exposure to antigens in early life have been hypothesized to lead to differences in immune status in individuals from different populations, which may have implications for immune responses in later years.Methods: Venous blood from HIV-negative adolescents and blood from the umbilical cords of babies, born to HIV-negative women, post-delivery was collected and analysed using flow cytometry. T cell phenotype was determined from peripheral blood lymphocytes and cytomegalovirus (CMV) seropositivity was assessed by ELISA in adolescents.Results: HIV-negative Malawian adolescents were shown to have a lower percentage of naive T cells (CD45RO-CD62L(hi)CD11a(lo)), a higher proportion of memory T cells and a higher percentage of CD28(-) memory (CD28(-)CD45RO(+)) T cells compared to age-matched UK adolescents. Malawian adolescents also had a lower percentage of central memory (CD45RA(-)CCR7(+)) T cells and a higher percentage of stable memory (CD45RA(+)CCR7(-)) T cells than UK adolescents. All of the adolescents tested in Malawi were seropositive for CMV (59/59), compared to 21/58 (36%) of UK adolescents. CMV seropositivity in the UK was associated with a reduced percentage of naive T cells and an increased percentage of CD28- memory T cells in the periphery. No differences in the proportions of naive and memory T cell populations were observed in cord blood samples from the two sites.Conclusion: It is likely that these differences between Malawian and UK adolescents reflect a greater natural exposure to various infections, including CMV, in the African environment and may imply differences in the ability of these populations to induce and maintain immunological memory to vaccines and natural infections
Effectiveness of pre-entry active tuberculosis and post-entry latent tuberculosis screening in new entrants to the UK: a retrospective, population-based cohort study
BACKGROUND: Evaluating interventions that might lead to a reduction in tuberculosis in high-income countries with a low incidence of the disease is key to accelerate progress towards its elimination. In such countries, migrants are known to contribute a large proportion of tuberculosis cases to the burden. We assessed the effectiveness of screening for active tuberculosis before entry to the UK and for latent tuberculosis infection (LTBI) post-entry for reduction of tuberculosis in new-entrant migrants to the UK. Additionally, we investigated the effect of access to primary care on tuberculosis incidence in this population. METHODS: We did a retrospective, population-based cohort study of migrants from 66 countries who were negative for active tuberculosis at pre-entry screening between Jan 1, 2011, and Dec 31, 2014, and eligible for LTBI screening. We used record linkage to track their first contact with primary care, uptake of LTBI screening, and development of active tuberculosis in England, Wales, and Northern Ireland. To assess the effectiveness of the pre-entry screening programme, we identified a control group of migrants who were not screened for active tuberculosis using the specific code for new entrants to the UK registering in primary care within the National Health Service patient registration data system. Our primary outcome was development of active tuberculosis notified to the National Enhanced Tuberculosis Surveillance System. FINDINGS: Our cohort comprised 224 234 migrants who were screened for active tuberculosis before entry to the UK and a control group of 118 738 migrants who were not. 103 990 (50%) migrants who were screened for active tuberculosis registered in primary care; all individuals in the control group were registered in primary care. 1828 tuberculosis cases were identified during the cohort time, of which 31 were prevalent. There were 26 incident active tuberculosis cases in migrants with no evidence of primary care registration, and 1771 cases in the entire cohort of migrants who registered in primary care (n=222 728), giving an incidence rate of 174 (95% CI 166-182) per 100 000 person-years. 672 (1%) of 103 990 migrants who were screened for active tuberculosis went on to develop tuberculosis compared with 1099 (1%) of 118 738 not screened for active tuberculosis (incidence rate ratio [IRR] 1·49, 95% CI 1·33-1·67; p<0·0001). 2451 (1%) of the 222 728 migrants registered in primary care were screened for LTBI, of whom 421 (17%) tested positive and 1961 (80%) tested negative; none developed active tuberculosis within the observed time period. Migrants settling in the least deprived areas had a decreased risk of developing tuberculosis (IRR 0·74, 95% CI 0·62-0·89; p=0·002), and time from UK arrival to primary care registration of 1 year or longer was associated with increased risk of active tuberculosis (2·96, 2·59-3·38; p<0·0001). INTERPRETATION: Pre-entry tuberculosis screening, early primary care registration, and LTBI screening are strongly and independently associated with a lower tuberculosis incidence in new-entrant migrants. FUNDING: National Institute for Health Research (NIHR) Health Protection Research Unit in Respiratory Infections and NIHR Imperial Biomedical Research Centre
Effectiveness of pre-entry active tuberculosis and post-entry latent tuberculosis screening in new entrants to the UK: a retrospective, population-based cohort study.
BACKGROUND: Evaluating interventions that might lead to a reduction in tuberculosis in high-income countries with a low incidence of the disease is key to accelerate progress towards its elimination. In such countries, migrants are known to contribute a large proportion of tuberculosis cases to the burden. We assessed the effectiveness of screening for active tuberculosis before entry to the UK and for latent tuberculosis infection (LTBI) post-entry for reduction of tuberculosis in new-entrant migrants to the UK. Additionally, we investigated the effect of access to primary care on tuberculosis incidence in this population. METHODS: We did a retrospective, population-based cohort study of migrants from 66 countries who were negative for active tuberculosis at pre-entry screening between Jan 1, 2011, and Dec 31, 2014, and eligible for LTBI screening. We used record linkage to track their first contact with primary care, uptake of LTBI screening, and development of active tuberculosis in England, Wales, and Northern Ireland. To assess the effectiveness of the pre-entry screening programme, we identified a control group of migrants who were not screened for active tuberculosis using the specific code for new entrants to the UK registering in primary care within the National Health Service patient registration data system. Our primary outcome was development of active tuberculosis notified to the National Enhanced Tuberculosis Surveillance System. FINDINGS: Our cohort comprised 224 234 migrants who were screened for active tuberculosis before entry to the UK and a control group of 118 738 migrants who were not. 103 990 (50%) migrants who were screened for active tuberculosis registered in primary care; all individuals in the control group were registered in primary care. 1828 tuberculosis cases were identified during the cohort time, of which 31 were prevalent. There were 26 incident active tuberculosis cases in migrants with no evidence of primary care registration, and 1771 cases in the entire cohort of migrants who registered in primary care (n=222 728), giving an incidence rate of 174 (95% CI 166-182) per 100 000 person-years. 672 (1%) of 103 990 migrants who were screened for active tuberculosis went on to develop tuberculosis compared with 1099 (1%) of 118 738 not screened for active tuberculosis (incidence rate ratio [IRR] 1·49, 95% CI 1·33-1·67; p<0·0001). 2451 (1%) of the 222 728 migrants registered in primary care were screened for LTBI, of whom 421 (17%) tested positive and 1961 (80%) tested negative; none developed active tuberculosis within the observed time period. Migrants settling in the least deprived areas had a decreased risk of developing tuberculosis (IRR 0·74, 95% CI 0·62-0·89; p=0·002), and time from UK arrival to primary care registration of 1 year or longer was associated with increased risk of active tuberculosis (2·96, 2·59-3·38; p<0·0001). INTERPRETATION: Pre-entry tuberculosis screening, early primary care registration, and LTBI screening are strongly and independently associated with a lower tuberculosis incidence in new-entrant migrants. FUNDING: National Institute for Health Research (NIHR) Health Protection Research Unit in Respiratory Infections and NIHR Imperial Biomedical Research Centre
Total immersion : Designing for affective symbiosis in a virtual reality game with haptics, biosensors, and emotive agents
Peer reviewe
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