The prevalence of developmental defects of enamel in a cohort of adults with cystic fibrosis - A cross sectional study.

OBJECTIVES: Cystic Fibrosis is an autosomal recessive condition. It is a multisystem disease treated with a broad range of pharmacological therapies, diet and nutrition, and physiotherapy. Previous studies suggest that people with cystic fibrosis have a higher prevalence of developmental defects of enamel which may place this population at a greater risk of developing oral diseases such as caries. The aim of this study was to assess a cohort of people with cystic fibrosis (PwCF) for the presence of developmental defects of enamel and compare the results with a control group of people without cystic fibrosis. METHODS: A cross sectional study involving 92 participants with cystic fibrosis and 92 controls was conducted in Cork University Dental School & Hospital. All participants completed a detailed questionnaire prior to undergoing a full clinical examination. The Developmental Defect of Enamel Index was used as a measurement index. All data was statistically analysed with the help of statisticians from Cystic Fibrosis Registry of Ireland. RESULTS: 64 % (n = 59) of PwCF had enamel defects compared to just 30 % (n = 28) of people without cystic fibrosis. The median number of teeth affected by enamel defects in the study group was 1.5, compared to 0 in the control group. CONCLUSION: In this study the cohort of PwCF had more enamel defects than people without CF. Further research is required to investigate the aetiology of these findings. CLINICAL SIGNIFICANCE: Clinicians should be vigilant after teeth have erupted in PwCF as they may have an increased susceptibility to developmental defects of enamel.

Periodontal disease prevalence and oral hygiene status of adults with cystic fibrosis: A case-control study.

AIM: To investigate the prevalence of gingivitis and periodontitis, and the oral hygiene status of adults with cystic fibrosis (CF) in the Republic of Ireland. MATERIALS AND METHODS: A case-control study in the form of a clinical examination of 92 adults with a diagnosis of CF was carried out in the adult CF unit in Cork University Hospital. A 40-item questionnaire was used to capture socio-demographic variables and medical and dental information. Two calibrated examiners carried out a periodontal assessment on participants, using the WHO-recommended CPI-modified index, and oral hygiene status was measured using the Greene-Vermillion index. The results were compared with a population-based control group of similar socio-demographic profile. RESULTS: Oral hygiene levels (plaque and calculus) were significantly worse in people with CF, with a median plaque index of 0.83 (interquartile range [IQR] 0.333-1.542) in the CF group compared with 0.5 (IQR 0.167-0.667) in the non-CF group. Calculus index in the CF group was 0.33 (IQR 0.17-0.83) compared with 0.33 (IQR 0.125-0.33) in the non-CF group. However, periodontal disease levels were significantly lower in the CF group. Gingivitis (bleeding on probing ≥ 10% sites) was seen in 67.4% of the CF group, compared with 83.7% of the non-CF group, OR 0.365 (95% confidence interval [CI] 0.181-0.736), relative risk (RR) 0.779 (95% CI 0.655-0.928). Mild periodontitis (periodontal probing depth [PPD] < 5 mm) was seen in 15.2% of the CF group, compared with 31.5% of the non-CF group, OR 0.390 (CI 0.190-0.800), RR 0.483 (95% CI 0.273-0.852). Severe periodontitis (PPD ≥ 6 mm) was seen in 0% of the CF group, compared with 9.8% of the non-CF group. There was a tendency, albeit non-significant, towards reduced periodontitis in PWCF who regularly took antibiotics, particularly azithromycin. CONCLUSIONS: In this study, adults with CF had poor oral hygiene practices, with high levels of plaque and calculus. Despite this finding, adults with CF had lower levels of clinical gingivitis and periodontitis than seen in a non-CF control group. Further study is required to examine the causes of this phenomenon.

Improvement in Lung Clearance Index and Chest Computed Tomography Scores with Elexacaftor/Tezacaftor/Ivacaftor Treatment in People with Cystic Fibrosis Aged 12 Years and Older - The RECOVER Trial.

Rationale: Clinical trials have shown that use of elexacaftor/tezacaftor/ivacaftor (ETI) is associated with improvements in sweat chloride, pulmonary function, nutrition, and quality of life in people with cystic fibrosis (CF). Little is known about the impact of ETI on ventilation inhomogeneity and lung structure. Objectives: RECOVER is a real-world study designed to measure the impact of ETI in people with CF. The primary endpoints were lung clearance (lung clearance index; LCI2.5) and FEV1. Secondary endpoints included spirometry-controlled chest computed tomography (CT) scores. Methods: The study was conducted in seven sites in Ireland and the United Kingdom. Participants ages 12 years and older who were homozygous for the F508del mutation (F508del/F508del) or heterozygous for F508del and a minimum-function mutation (F508del/MF) were recruited before starting ETI and were followed up over 12 months. LCI2.5 was measured using nitrogen multiple breath washout (MBW) at baseline and at 6 and 12 months. Spirometry was performed as per the criteria of the American Thoracic Society and the European Respiratory Society. Spirometry-controlled chest CT scans were performed at baseline and at 12 months. CT scans were scored using the Perth Rotterdam Annotated Grid Morphometric Analysis (PRAGMA) system. Other outcome measures include weight, height, Cystic Fibrosis Quality of Life Questionnaire-Revised (CFQ-R), and sweat chloride. Measurements and Main Results: One hundred seventeen people with CF ages 12 and older were recruited to the study. Significant improvements were seen in LCI scores (-2.5; 95% confidence interval [CI], -3.0, -2.0) and in the percents predicted for FEV1 (8.9; 95% CI, 7.0, 10.9), FVC (6.6; 95% CI, 4.9, 8.3), and forced expiratory flow between 25% and 75% of expired volume (12.4; 95% CI, 7.8, 17.0). Overall PRAGMA-CF scores reflecting airway disease improved significantly (-3.46; 95% CI, -5.23, -1.69). Scores for trapped air, mucus plugging, and bronchial wall thickening improved significantly, but bronchiectasis scores did not. Sweat chloride levels decreased in both F508del/F508del (-43.1; 95% CI, -47.4, -38.9) and F508del/MF (-42.8; 95% CI, -48.5, -37.2) groups. Scores on the Respiratory Domain of the CFQ-R improved by 14.2 points (95% CI, 11.3, 17.2). At 1 year, sweat chloride levels were significantly lower for the F508del/F508del group compared with scores for the F508del/MF group (33.93 vs. 53.36, P < 0.001). Conclusions: ETI is associated with substantial improvements in LCI2.5, spirometry, and PRAGMA-CF CT scores in people with CF ages 12 years and older. ETI led to improved nutrition and quality of life. People in the F508del/F508del group had significantly lower sweat chloride on ETI treatment compared with the F508del/MF group. Clinical trial registered with www.clinicaltrials.gov (NCT04602468).

The clinical impact of Lumacaftor-Ivacaftor on structural lung disease and lung function in children aged 6-11 with cystic fibrosis in a real-world setting.

BACKGROUND: Data from clinical trials of lumacaftor-ivacaftor (LUM-IVA) demonstrate improvements in lung clearance index (LCI) but not in FEV1 in children with Cystic Fibrosis (CF) aged 6-11 years and homozygous for the Phe508del mutation. It is not known whether LUM/IVA use in children can impact the progression of structural lung disease. We sought to determine the real-world impact of LUM/IVA on lung structure and function in children aged 6-11 years. METHODS: This real-world observational cohort study was conducted across four paediatric sites in Ireland over 24-months using spirometry-controlled CT scores and LCI as primary outcome measures. Children commencing LUM-/IVA as part of routine care were included. CT scans were manually scored with the PRAGMA CF scoring system and analysed using the automated bronchus-artery (BA) method. Secondary outcome measures included rate of change of ppFEV1, nutritional indices and exacerbations requiring hospitalisation. RESULTS: Seventy-one participants were recruited to the study, 31 of whom had spirometry-controlled CT performed at baseline, and after one year and two years of LUM/IVA treatment. At two years there was a reduction from baseline in trapped air scores (0.13 to 0.07, p = 0.016), but an increase from baseline in the % bronchiectasis score (0.84 to 1.23, p = 0.007). There was no change in overall % disease score (2.78 to 2.25, p = 0.138). Airway lumen to pulmonary artery ratios (AlumenA ratio) were abnormal at baseline and worsened over the course of the study. In 28 participants, the mean annual change from baseline LCI2.5 (-0.055 (-0.61 to 0.50), p = 0.85) measurements over two years were not significant. Improvements from baseline in weight (0.10 (0.06 to 0.15, p < 0.0001), height (0.05 (0.02 to 0.09), p = 0.002) and BMI (0.09 (0.03 to 0.15) p = 0.005) z-scores were seen with LUM/IVA treatment. The mean annual change from baseline ppFEV1 (-2.45 (-4.44 to 2.54), p = 0.66) measurements over two years were not significant. CONCLUSION: In a real-world setting, the use of LUM/IVA over two years in children with CF aged 6-11 resulted in improvements in air trapping on CT but worsening in bronchiectasis scores. Our results suggest that LUM/IVA use in this age group improves air trapping but does not prevent progression of bronchiectasis over two years of treatment.

Telehealth in Cystic Fibrosis. A systematic review incorporating a novel scoring system and expert weighting to identify a 'top 10 manuscripts' to inform future best practices implementation.

The ongoing development and integration of telehealth within CF care has been accelerated in response to the Covid-19 pandemic, with many centres publishing their experiences. Now, as the restrictions of the pandemic ease, the use of telehealth appears to be waning, with many centres returning to routine traditional face-to-face services. For most, telehealth is not integrated into clinical care models, and there is a lack of guidance on how to integrate such a service into clinical care. The aims of this systematic review were to first identify manuscripts which may inform best CF telehealth practices, and second, to analyse these finding to determine how the CF community may use telehealth to improve care for patients, families, and Multidisciplinary Teams into the future. To achieve this, the PRISMA review methodology was utilised, in combination with a modified novel scoring system that consolidates expert weighting from key CF stakeholders, allowing for the manuscripts to be placed in a hierarchy in accordance with their scientific robustness. From the 39 found manuscripts, the top ten are presented and further analysed. The top ten manuscripts are exemplars of where telehealth is used effectively within CF care at this time, and demonstrate specific use cases of its potential best practices. However, there is a lack of guidance for implementation and clinical decision making, which remains an area for improvement. Thus, it is suggested that further work explores and provides guidance for standardised implementation into CF clinical practice.

Assessment of the Environmental Impact of Food Consumption in Ireland-Informing a Transition to Sustainable Diets.

Dietary changes are required to mitigate the climatic impact of food consumption. Food consumption databases can support the development of sustainable food based dietary guidelines (SFBDG) when linked to environmental indicators. An improved knowledge base is crucial to the transition to sustainable diets, and multiple environmental indicators should be considered to ensure this transition is evidence based and accounts for trade-offs. The current study aimed to quantify the environmental impact of daily diets across population groups in Ireland. Nationally representative food consumption surveys for Irish children (NCFSII; 2017-2018), teenagers (NTFSII; 2019-2020), and adults (NANS; 2008-2010) were used in this analysis. Blue water use (L) and greenhouse gas emissions (GHGe; kgCO2eq) were assigned at food level to all surveys. Cropland (m2), nitrogen (kgN/t), and phosphorous use (kgP/t) were assigned at the agricultural level for adults. Multiple linear regressions, Spearman correlations, and ANCOVAs with Bonferroni corrections were conducted. Higher environmental impact diets were significantly associated with demographic factors such as age, education status, residential location, and sex, but these associations were not consistent across population groups. The median greenhouse gas emissions were 2.77, 2.93, and 4.31 kgCO2eq, and freshwater use per day was 88, 144, and 307 L for children, teenagers, and adults, respectively. The environmental impact of the Irish population exceeded the planetary boundary for GHGe by at least 148% for all population groups, however the boundary for blue water use was not exceeded. Meat and meat alternatives (27-44%); eggs, dairy, and dairy alternatives (15-21%); and starchy staples (10-20%) were the main contributors to GHGe. For blue water use, the highest contributors were meat and meat alternatives in children; savouries, snacks, nuts, and seeds in teenagers; and eggs, dairy, and dairy alternatives in adults (29-52%). In adults, cropland use, nitrogen use, and phosphorous use exceeded planetary boundaries by 277-382%. Meat, dairy, and grains were the main contributors to cropland, nitrogen, and phosphorous use (79-88%). The quantified environmental impact of Irish diets provides a baseline analysis, against which it will be possible to track progress towards sustainable diets, and the basis for the development of Sustainable Food Based Dietary Guidelines in Ireland.

An Evaluation of Probability of Adequate Nutrient Intake (PANDiet) Scores as a Diet Quality Metric in Irish National Food Consumption Data.

Identifying reliable metrics which measure the quality of a diet to promote nutrient adequacy and long-term health is an important step in the development of a sustainable food system. The Probability of Adequate Nutrient Intake (PANDiet) scoring system has been used as a measure of dietary quality in interdisciplinary research in recent years. The aim of the current study is to apply the PANDiet scoring system, and to assess the validity of the score as a metric of nutritional adequacy, within the Irish population. The Irish National Adult Nutrition Survey is a representative database with detailed data on nutrient intakes (18−90 years; n = 1051 valid-reporters; 2008−2010) and biofluid analytes (blood n = 786; urine n = 778). The PANDiet scoring system was expanded to include seven macronutrients, twelve micronutrients, nine minerals, and total energy using an established methodology. PANDiet scores were assessed against the Alternate Healthy Eating Index (AHEI) and Alternate Mediterranean Diet (aMED) food-based scores. The average score for the population (µ) was 63.69 ± 0.23 and ranged from 38.27 to 89.74. Higher PANDiet scores were significantly associated with males, higher educated participants, non-smokers, and low-energy-dense diets (p < 0.001). Females between the ages of 18 and 35 had a significantly lower nutrient adequacy score (µ 59.17). PANDiet scores were significantly correlated with serum folate, riboflavin status, serum vitamin D (p < 0.05) and with AHEI and aMED scores (Rs 0.45 and 0.43, p < 0.0001). The nutritional contribution of food groups varied between genders and low, moderate, and high nutritional adequacy groups. The PANDiet scoring system facilitated a detailed analysis of nutritional adequacy across sub-groups of the population, and is a comprehensive and valid diet quality metric in Irish databases.

Impact of the common MTHFR 677C→T polymorphism on blood pressure in adulthood and role of riboflavin in modifying the genetic risk of hypertension: evidence from the JINGO project.

BACKGROUND: Genome-wide and clinical studies have linked the 677C→T polymorphism in the gene encoding methylenetetrahydrofolate reductase (MTHFR) with hypertension, whilst limited evidence shows that intervention with riboflavin (i.e. the MTHFR co-factor) can lower blood pressure (BP) in hypertensive patients with the variant MTHFR 677TT genotype. We investigated the impact of this common polymorphism on BP throughout adulthood and hypothesised that riboflavin status would modulate the genetic risk of hypertension. METHODS: Observational data on 6076 adults of 18-102 years were drawn from the Joint Irish Nutrigenomics Organisation project, comprising the Trinity-Ulster Department of Agriculture (TUDA; volunteer sample) and the National Adult Nutrition Survey (NANS; population-based sample) cohorts. Participants were recruited from the Republic of Ireland and Northern Ireland (UK) in 2008-2012 using standardised methods. RESULTS: The variant MTHFR 677TT genotype was identified in 12% of adults. From 18 to 70 years, this genotype was associated with an increased risk of hypertension (i.e. systolic BP ≥ 140 and/or a diastolic BP ≥ 90 mmHg): odds ratio (OR) 1.42, 95% confidence interval (CI) 1.07 to 1.90; P = 0.016, after adjustment for antihypertensive drug use and other significant factors, namely, age, male sex, BMI, alcohol and total cholesterol. Low or deficient biomarker status of riboflavin (observed in 30.2% and 30.0% of participants, respectively) exacerbated the genetic risk of hypertension, with a 3-fold increased risk for the TT genotype in combination with deficient riboflavin status (OR 3.00, 95% CI, 1.34-6.68; P = 0.007) relative to the CC genotype combined with normal riboflavin status. Up to 65 years, we observed poorer BP control rates on antihypertensive treatment in participants with the TT genotype (30%) compared to those without this variant, CT (37%) and CC (45%) genotypes (P < 0.027). CONCLUSIONS: The MTHFR 677TT genotype is associated with higher BP independently of homocysteine and predisposes adults to an increased risk of hypertension and poorer BP control with antihypertensive treatment, whilst better riboflavin status is associated with a reduced genetic risk. Riboflavin intervention may thus offer a personalised approach to prevent the onset of hypertension in adults with the TT genotype; however, this requires confirmation in a randomised trial in non-hypertensive adults.

Associations between health literacy and patient outcomes in adolescents and young adults with cystic fibrosis.

BACKGROUND: Interactive health literacy (HL) skills enable individuals to participate more fully in healthcare activities and play a role in improving their outcomes. We examine the associations between HL and cystic fibrosis (CF) outcomes and compare HL in a sample from both the Irish CF and general populations. METHODS: A total of251 CF Registry participants aged 13-30 years completed the HLS-EU-Q16 survey and a disease-specific instrument for measuring quality of life (QoL) in CF. Health outcome and healthcare resource utilization (HCRU) data were sourced from the registry. CF patient outcomes were examined using generalized linear models (GLMs) with interactive HL categorization included as a factor. General population interactive HL data are from the 2011 European HL Survey (HLS-EU). Interactive HL in 180 age-sex matched CF and general population individuals was examined using a GLM with study population, sex and educational level included as factors and age as a covariate. RESULTS: Sufficient interactive HL (total sum score ≥13) was self-reported by 81.7% of individuals with CF. Sufficient HL was associated with fewer outpatient visits [7.02(SD = 6.7: 7.4) vs. 8.74(SD = 7.9: 9.6), P < 0.001], days hospitalized [10.25(SD = 9.8: 10.7) vs. 12.8(SD = 11.8: 13.9), P < 0.001], days on intravenous antibiotics [15.3(SD = 14.7: 15.8) vs. 19.7(18.5: 21.1), P < 0.001], days on oral antibiotics [27.4(SD = 26.7: 28.1) vs. 48.48(38.7: 42.4), P < 0.001] and better QoL [77.1(SD = 75.4-78.9) vs. 64.6(60.8-68.3), P < 0.001]. Mean HL scores in CF and general populations were sufficient, although higher among individuals with CF (14.3 vs. 13.1, P < 0.01). CONCLUSION: CF adolescents and young adults with sufficient levels of HL to obtain, understand, appraise and apply health information have better health-related outcomes.

Longitudinal Trends in Real-World Outcomes after Initiation of Ivacaftor. A Cohort Study from the Cystic Fibrosis Registry of Ireland.

RATIONALE: Patient registries have the potential to collect and analyze high-quality postauthorization data on new medicines. OBJECTIVES: We used cystic fibrosis (CF) registry data to assess outcomes after the initiation of ivacaftor, a CF transmembrane conductance regulator (CFTR) potentiator approved for the treatment of CF with a defective gating CFTR mutation. METHODS: Longitudinal trends were examined using mixed-effects regression analysis in 80 ivacaftor-treated patients with CF aged 6 to 56 years registered with the CF Registry of Ireland with at least 36 months of before and after commencement data. The effects of ivacaftor treatment on forced expiratory volume in 1 second (FEV1) % predicted, body mass index (BMI), hospitalization for pulmonary exacerbation, and oral and intravenous antibiotic use were assessed. RESULTS: In the 36 months after ivacaftor initiation, FEV1% predicted improved by 2.26% per annum (95% confidence interval [CI], 0.2 to 4.3) for patients aged younger than 12 years, remained unchanged for 12- to younger than 18-year-olds (95% CI, -1.9 to 2.9), and declined in adults by 1.74% per annum (95% CI, -3.1 to -0.4). BMI in adults increased 0.28 kg/m2 per annum (95% CI, 0.03 to 0.5), and there was no significant change in BMI z-score in children (95% CI, -0.01 to 0.1). In the year after ivacaftor initiation, intravenous antibiotic treatment reduced by 46% (95% CI, -62.5% to -23.3%, oral antibiotic treatment reduced by 49% (95% CI, -61.1% to -32.1%), and there was no significant reduction in hospitalization (95% CI, -59.2% to 9.7%). CONCLUSIONS: In this study of real-world CF registry data, clinical outcomes improved and healthcare resource utilization decreased after commencing ivacaftor.

Weed suppression greatly increased by plant diversity in intensively managed grasslands: A continental-scale experiment.

Grassland diversity can support sustainable intensification of grassland production through increased yields, reduced inputs and limited weed invasion. We report the effects of diversity on weed suppression from 3 years of a 31-site continental-scale field experiment.At each site, 15 grassland communities comprising four monocultures and 11 four-species mixtures based on a wide range of species' proportions were sown at two densities and managed by cutting. Forage species were selected according to two crossed functional traits, "method of nitrogen acquisition" and "pattern of temporal development".Across sites, years and sown densities, annual weed biomass in mixtures and monocultures was 0.5 and 2.0 t  DM ha-1 (7% and 33% of total biomass respectively). Over 95% of mixtures had weed biomass lower than the average of monocultures, and in two-thirds of cases, lower than in the most suppressive monoculture (transgressive suppression). Suppression was significantly transgressive for 58% of site-years. Transgressive suppression by mixtures was maintained across years, independent of site productivity.Based on models, average weed biomass in mixture over the whole experiment was 52% less (95% confidence interval: 30%-75%) than in the most suppressive monoculture. Transgressive suppression of weed biomass was significant at each year across all mixtures and for each mixture.Weed biomass was consistently low across all mixtures and years and was in some cases significantly but not largely different from that in the equiproportional mixture. The average variability (standard deviation) of annual weed biomass within a site was much lower for mixtures (0.42) than for monocultures (1.77). Synthesis and applications. Weed invasion can be diminished through a combination of forage species selected for complementarity and persistence traits in systems designed to reduce reliance on fertiliser nitrogen. In this study, effects of diversity on weed suppression were consistently strong across mixtures varying widely in species' proportions and over time. The level of weed biomass did not vary greatly across mixtures varying widely in proportions of sown species. These diversity benefits in intensively managed grasslands are relevant for the sustainable intensification of agriculture and, importantly, are achievable through practical farm-scale actions.

The importance of species identity and interactions for multifunctionality depends on how ecosystem functions are valued.

Studies investigating how biodiversity affects ecosystem functioning increasingly focus on multiple functions measured simultaneously ("multifunctionality"). However, few such studies assess the role of species interactions, particularly under alternative environmental scenarios, despite interactions being key to ecosystem functioning. Here we address five questions of central importance to ecosystem multifunctionality using a terrestrial animal system. (1) Does the contribution of individual species differ for different ecosystem functions? (2) Do inter-species interactions affect the delivery of single functions and multiple functions? (3) Does the community composition that maximizes individual functions also maximize multifunctionality? (4) Is the functional role of individual species, and the effect of interspecific interactions, modified by changing environmental conditions? (5) How do these roles and interactions change under varying scenarios where ecosystem services are weighted to reflect different societal preferences? We manipulated species' relative abundance in dung beetle communities and measured 16 functions contributing to dung decomposition, plant productivity, nutrient recycling, reduction of greenhouse gases, and microbial activity. Using the multivariate diversity-interactions framework, we assessed how changes in species identity, composition, and interspecific interactions affected these functions in combination with an environmental driver (increased precipitation). This allowed us to identify key species and interactions across multiple functions. We then developed a desirability function approach to examine how individual species and species mixtures contribute to a desired state of overall ecosystem functioning. Species contributed unequally to individual functions, and to multifunctionality, and individual functions were maximized by different community compositions. Moreover, the species and interactions important for maintaining overall multifunctionality depended on the weight given to individual functions. Optimal multifunctionality was context-dependent, and sensitive to the valuation of services. This combination of methodological approaches allowed us to resolve the interactions and indirect effects among species that drive ecosystem functioning, revealing how multiple aspects of biodiversity can simultaneously drive ecosystem functioning. Our results highlight the importance of a multifunctionality perspective for a complete assessment of species' functional contributions.

Biodiversity and ecosystem function: making sense of numerous species interactions in multi-species communities.

Understanding the biodiversity and ecosystem function relationship can be challenging in species-rich ecosystems. Traditionally, species richness has been relied on heavily to explain changes in ecosystem function across diversity gradients. Diversity-Interactions models can test how ecosystem function is affected by species identity, species interactions, and evenness, in addition to richness. However, in a species-rich system, there may be too many species interactions to allow estimation of each coefficient, and if all interaction coefficients are estimable, they may be devoid of any sensible biological meaning. Parsimonious descriptions using constraints among interaction coefficients have been developed but important variability may still remain unexplained. Here, we extend Diversity-Interactions models to describe the effects of diversity on ecosystem function using a combination of fixed coefficients and random effects. Our approach provides improved standard errors for testing fixed coefficients and incorporates lack-of-fit tests for diversity effects. We illustrate our methods using data from a grassland and a microbial experiment. Our framework considerably reduces the complexities associated with understanding how species interactions contribute to ecosystem function in species-rich ecosystems.

A cross-sectional observation on habitual non-alcoholic beverage consumption among adolescents from four Irish post-primary schools.

OBJECTIVE: No up-to-date data on the dietary intake of Irish adolescents are available. The aim of the present pilot study was to obtain and compare cross-sectional information on habitual adolescent beverage consumption between four distinct post-primary schools in the Republic of Ireland, in 2014-2015. DESIGN: A cross-sectional observation study. A beverage consumption questionnaire was used to obtain data on beverage intake and influences on consumption. SETTING: Four post-primary mixed-sex schools in Ireland representing the following school classifications were selected for the study: urban fee-paying, urban disadvantaged, rural fee-paying and rural disadvantaged. SUBJECTS: Students (n 761) aged 12-18 years. RESULTS: Data were analysed by Kruskal-Wallis (non-parametric) ANOVA to compare the distribution of beverage consumption across the schools. Water was the most highly consumed beverage among students from all four schools (median 1425 ml/d). Students from urban and rural disadvantaged schools reported a significantly higher volume of carbonated beverage intake than students from fee-paying schools. Students from an urban disadvantaged school also reported a significantly higher volume of carbonated beverage and energy drink intake compared with the other three schools. Students from an urban fee-paying school reported the highest consumption of water, while rural disadvantaged school students were the biggest consumers of tea and milk. CONCLUSIONS: Significant differences in beverage consumption (ml/d) were reported by adolescents from four schools in Ireland. Surveillance on current beverage consumption trends among adolescents is vital to guide policies and interventions, and for appropriate targeting of resources.

Phenotypic factors influencing the variation in response of circulating cholesterol level to personalised dietary advice in the Food4Me study.

Individual response to dietary interventions can be highly variable. The phenotypic characteristics of those who will respond positively to personalised dietary advice are largely unknown. The objective of this study was to compare the phenotypic profiles of differential responders to personalised dietary intervention, with a focus on total circulating cholesterol. Subjects from the Food4Me multi-centre study were classified as responders or non-responders to dietary advice on the basis of the change in cholesterol level from baseline to month 6, with lower and upper quartiles defined as responder and non-responder groups, respectively. There were no significant differences between demographic and anthropometric profiles of the groups. Furthermore, with the exception of alcohol, there was no significant difference in reported dietary intake, at baseline. However, there were marked differences in baseline fatty acid profiles. The responder group had significantly higher levels of stearic acid (18 : 0, P=0·034) and lower levels of palmitic acid (16 : 0, P=0·009). Total MUFA (P=0·016) and total PUFA (P=0·008) also differed between the groups. In a step-wise logistic regression model, age, baseline total cholesterol, glucose, five fatty acids and alcohol intakes were selected as factors that successfully discriminated responders from non-responders, with sensitivity of 82 % and specificity of 83 %. The successful delivery of personalised dietary advice may depend on our ability to identify phenotypes that are responsive. The results demonstrate the potential use of metabolic profiles in identifying response to an intervention and could play an important role in the development of precision nutrition.

Nitrogen yield advantage from grass-legume mixtures is robust over a wide range of legume proportions and environmental conditions.

Current challenges to global food security require sustainable intensification of agriculture through initiatives that include more efficient use of nitrogen (N), increased protein self-sufficiency through homegrown crops, and reduced N losses to the environment. Such challenges were addressed in a continental-scale field experiment conducted over 3 years, in which the amount of total nitrogen yield (Ntot ) and the gain of N yield in mixtures as compared to grass monocultures (Ngainmix ) was quantified from four-species grass-legume stands with greatly varying legume proportions. Stands consisted of monocultures and mixtures of two N2 -fixing legumes and two nonfixing grasses. The amount of Ntot of mixtures was significantly greater (P ≤ 0.05) than that of grass monocultures at the majority of evaluated sites in all 3 years. Ntot and thus Ngainmix increased with increasing legume proportion up to one-third of legumes. With higher legume percentages, Ntot and Ngainmix did not continue to increase. Thus, across sites and years, mixtures with one-third proportion of legumes attained ~95% of the maximum Ntot acquired by any stand and had 57% higher Ntot than grass monocultures. Realized legume proportion in stands and the relative N gain in mixture (Ngainmix /Ntot in mixture) were most severely impaired by minimum site temperature (R = 0.70, P = 0.003 for legume proportion; R = 0.64, P = 0.010 for Ngainmix /Ntot in mixture). Nevertheless, the relative N gain in mixture was not correlated to site productivity (P = 0.500), suggesting that, within climatic restrictions, balanced grass-legume mixtures can benefit from comparable relative gains in N yield across largely differing productivity levels. We conclude that the use of grass-legume mixtures can substantially contribute to resource-efficient agricultural grassland systems over a wide range of productivity levels, implying important savings in N fertilizers and thus greenhouse gas emissions and a considerable potential for climate change mitigation.

Effects of over-winter green cover on soil solution nitrate concentrations beneath tillage land.

There is a growing need to reduce nitrogen losses from agricultural systems to increase food production while reducing negative environmental impacts. The efficacy of vegetation cover for reducing nitrate leaching in tillage systems during fallow periods has been widely investigated. Nitrate leaching reductions by natural regeneration (i.e. growth of weeds and crop volunteers) have been investigated to a lesser extent than reductions by planted cover crops. This study compares the efficacy of natural regeneration and a sown cover crop (mustard) relative to no vegetative cover under both a reduced tillage system and conventional plough-based system as potential mitigation measures for reducing over-winter soil solution nitrate concentrations. The study was conducted over three winter fallow seasons on well drained soil, highly susceptible to leaching, under temperate maritime climatic conditions. Mustard cover crop under both reduced tillage and conventional ploughing was observed to be an effective measure for significantly reducing nitrate concentrations. Natural regeneration under reduced tillage was found to significantly reduce the soil solution nitrate concentrations. This was not the case for the natural regeneration under conventional ploughing. The improved efficacy of natural regeneration under reduced tillage could be a consequence of potential stimulation of seedling germination by the autumn reduced tillage practices and improved over-winter plant growth. There was no significant effect of tillage practices on nitrate concentrations. This study shows that over winter covers of mustard and natural regeneration, under reduced tillage, are effective measures for reducing nitrate concentrations in free draining temperate soils.

Effects of over-winter green cover on groundwater nitrate and dissolved organic carbon concentrations beneath tillage land.

Application of over-winter green cover (e.g. cover crops) as a measure for reducing nitrate losses from tillage land has been frequently investigated, especially in the unsaturated zone. Monitoring of groundwater is less common in these studies. Studies on groundwater responses to different land treatments can be challenging because they can be influenced by various conditions, such as recharge, seasonal variations, and aquifer properties, often occurring at different time scales than surface water processes. The aim of this study was to evaluate groundwater nitrate (NO(3)(-)N) and dissolved organic carbon (DOC) concentration responses to different over-winter green covers: mustard, natural regeneration and no cover. A field experiment was designed and run for three years on tillage land underlain by a vulnerable sand and gravel aquifer in the south-east of Ireland. Results showed that over-winter green cover growth on tillage land can be an effective measure to reduce groundwater NO(3)(-)N concentrations. A significant decrease in groundwater NO(3)(-)N concentrations was observed under the mustard cover compared to no cover. All treatments, including no cover, showed a decline in groundwater NO(3)(-)N concentrations over time. A significant increase in groundwater DOC was also observed under the mustard cover. Although the overall groundwater DOC concentrations were low, the increased DOC occurrence in groundwater should be accounted for in carbon balances and could potentially enhance groundwater denitrification in cases where aquifer conditions may favour it.

Phylogenetically diverse grasslands are associated with pairwise interspecific processes that increase biomass.

Biodiversity is an important determinant of primary productivity in experimental ecosystems. We combine two streams of research on understanding the effects of biodiversity on ecosystem function: quantifying phylogenetic diversity as a predictor of biodiversity effects in species-rich systems and the contribution of pairwise interspecific interactions to ecosystem function. We developed a statistical model that partitions the effect of biodiversity into effects due to community phylogenetic diversity and other community properties (e.g., average pairwise interaction, between- and within-functional-group effects, and so forth). The model provides phylogenetically based species-level explanations of differences in ecosystem response for communities with differing species composition. In two well-known grassland experiments, the model approach provides a parsimonious description of the effects of diversity as being due to the joint effect of the average pairwise statistical interaction and to community phylogenetic diversity. Effects associated with functional groupings of species in communities are largely explained by community phylogenetic diversity. The model approach quantifies a direct link between a measure of the evolutionary diversity of species and their interactive contribution to ecosystem function. It proves a useful tool in developing a mechanistic understanding of variation in ecosystem function.