Denitrification and Nitrous Oxide Emissions in Annual Croplands, Perennial Grass Buffers, and Restored Perennial Grasslands

Inclusion of perennial vegetation filter strips (PFSs) in the toeslope of annual cropland watersheds can decrease NO3−–N losses to ground and surface waters. Although PFSs are similar to riparian buffers, the processes responsible for NO3−–N removal from PFSs are not well understood. Our objectives were to (i) determine the importance of denitrification as a sink for NO3−–N loss from PFSs and (ii) evaluate how PFSs alter the biophysical processes that affect the relative importance of N2O and N2 emissions. To address our objectives, we used a coupled field laboratory approach with experimental watersheds that included the following treatments: (i) PFSs covering the bottom 10% of the watershed and an annual corn–soybean crop rotation covering the remaining upslope 90% (PFS); (ii) 100% corn–soybean rotation (CORN); and (iii) 19-yr-old 100% restored native grassland (RNG). In situ N2O flux rates and laboratory N2O/(N2 + N2O) ratios were highest in CORN watersheds followed by PFS and RNG watersheds. In contrast, potentially mineralizable C and denitrification enzyme activity (DEA) were highest in PFS and RNG watersheds and lowest in CORN watersheds. Furthermore, there was a negative correlation between N2O/(N2 + N2O) ratio and DEA. In the laboratory, N2 fluxes were highest in PFS followed by RNG and CORN. These results indicate that PFS watersheds support greater total denitrification while emitting less N2O than croplands. Greater potentially mineralizable C in PFS and RNG suggest C availability is an important factor affecting more complete denitrification. These results suggest PFSs function similar to riparian buffers and have potential to reduce NO3−–N losses from annual croplands by denitrification to N2

Factors influencing the propensity to cycle to work

This paper describes the development of a mode choice model for the journey to work with special emphasis on the propensity to cycle. The model combines revealed preference (RP) and stated preference (SP) data to form a very large and comprehensive model. RP data from the National Travel Survey was combined with a specially commissioned RP survey. A number of SP surveys were also undertaken to examine the effects of different types of en-route and trip end cycle facilities and financial measures to encourage cycling. The development of the model is described in detail. The model was used to forecast trends in urban commuting shares over time and to predict the impacts of different measures to encourage cycling. Of the en-route cycle facilities, a completely segregated cycleway was forecast to have the greatest impact, but even the unfeasible scenario of universal provision of such facilities would only result in a 55% increase in cycling and a slight reduction in car commuting. Payments for cycling to work were found to be highly effective with a £2 daily payment almost doubling the level of cycling. The most effective policy would combine improvements in en-route facilities, a daily payment to cycle to work and comprehensive trip end facilities and this would also have a significant impact on car commuting

Comparing Nitrate Sink Strength in Perennial Filter Strips at Toeslopes of Cropland Watersheds

Integration of perennial filter strips (PFS) into the toeslopes of agricultural watersheds may decrease downstream nitrate (NO3) losses. However, long-term NO3 removal depends on the relative importance of several NO3 sinks in the PFS. Plant biomass and labile soil organic matter (SOM) are temporary NO3 sinks, while stable SOM is a long-term, but potentially finite, NO3 sink. In contrast, denitrification is a permanent NO3 sink. We investigated the relative importance of these NO3 sinks in PFS at the toeslope of row crop watersheds in Iowa. Using 25- × 30-cm in situ mesocosms, we added 15NO3 to PFS soils and quantified 15NO3–N recovery in plant biomass and SOM after one growing season. Further, we compared 15NO3–N recovery in particulate (relatively labile) and mineral-associated (relatively stable) SOM in mesocosms with and without growing perennial vegetation. To determine the potential importance of denitrification, we compared denitrification enzyme activity in soils from paired watersheds with and without PFS. Transfer of 15NO3–N into labile and stable SOM pools was rapid and initially independent of growing vegetation. However, SOM and plant biomass were both relatively minor NO3 sinks, accounting for 15NO3–N inputs. Denitrification enzyme activity data indicated that dissolved organic carbon derived from perennial vegetation increased potential denitrifier activity in PFS soils compared with row crop soils. Together, these results constrain SOM and plant biomass as NO3 sinks and indicate that denitrification was the most important NO3sink in perennial filter strips over one growing season

Soccer Player Characteristics in English Lower-League Development Programmes: The Relationships between Relative Age, Maturation, Anthropometry and Physical Fitness

The relative age effect (RAE) and its relationships with maturation, anthropometry, and physical performance characteristics were examined across a representative sample of English youth soccer development programmes. Birth dates of 1,212 players, chronologically age-grouped (i.e., U9's-U18's), representing 17 professional clubs (i.e., playing in Leagues 1 & 2) were obtained and categorised into relative age quartiles from the start of the selection year (Q1 = Sep-Nov; Q2 = Dec-Feb; Q3 = Mar-May; Q4 = Jun-Aug). Players were measured for somatic maturation and performed a battery of physical tests to determine aerobic fitness (Multi-Stage Fitness Test [MSFT]), Maximal Vertical Jump (MVJ), sprint (10 & 20m), and agility (T-Test) performance capabilities. Odds ratio's (OR) revealed Q1 players were 5.3 times (95% confidence intervals [CI]: 4.08-6.83) more likely to be selected than Q4's, with a particularly strong RAE bias observed in U9 (OR: 5.56) and U13-U16 squads (OR: 5.45-6.13). Multivariate statistical models identified few between quartile differences in anthropometric and fitness characteristics, and confirmed chronological age-group and estimated age at peak height velocity (APHV) as covariates. Assessment of practical significance using magnitude-based inferences demonstrated body size advantages in relatively older players (Q1 vs. Q4) that were very-likely small (Effect Size [ES]: 0.53-0.57), and likely to very-likely moderate (ES: 0.62-0.72) in U12 and U14 squads, respectively. Relatively older U12-U14 players also demonstrated small advantages in 10m (ES: 0.31-0.45) and 20m sprint performance (ES: 0.36-0.46). The data identify a strong RAE bias at the entry-point to English soccer developmental programmes. RAE was also stronger circa-PHV, and relatively older players demonstrated anaerobic performance advantages during the pubescent period. Talent selectors should consider motor function and maturation status assessments to avoid premature and unwarranted drop-out of soccer players within youth development programmes

Protocol for a feasibility multi-centre randomised controlled trial of a pre-operative two-week very low-calorie diet to reduce steatosis prior to liver resection (RESOLVE)

BACKGROUND: Hepatic steatosis (HS) increases morbidity and mortality associated with liver surgery (LS). Furthermore, patients with HS are more likely to require a blood transfusion, which is associated with worse short and long-term outcomes. Patients with HS requiring LS receive no specific dietary treatment or advice. A very low-calorie diet (VLCD) is commonly used before gallbladder and bariatric surgery to reduce liver volumes and associated intraoperative morbidity. These diets typically provide 800-1200 kcal/day over a 2-4-week period. Limited evidence suggests that a VLCD in patients with LS may result in better outcomes. METHODS: This study aims to test the feasibility of delivering a multi-centre randomised clinical trial to compare a dietary intervention (VLCD plus motivational instructions) versus treatment as usual (TAU) in people with HS having LS. This study will provide high-quality data to estimate screening rates, recruitment, randomisation, retention, and intervention adherence. The study will also determine the definitive trial\u27s most clinically relevant primary outcome. The study will also estimate resource use and costs associated with the delivery of the intervention. Seventy-two adults ≥ 18 who are scheduled to undergo elective LS and have a magnetic resonance imaging (MRI) identified HS will be recruited. Acceptability to the dietary intervention will be evaluated with food diaries and focus groups. Clinical and patient-reported outcomes will be collected at baseline, pre- and post-surgery, day of discharge, plus 30- and 90-day follow-up. DISCUSSION: This feasibility study will provide data on the acceptability and feasibility of a dietary intervention for patients with HS having LS. The intervention has been developed based on scientific evidence from other clinical areas and patient experience; therefore, it is safe for this patient group. Patients with experience of LS and VLCDs have advised throughout the development of the study protocol. The findings will inform the design of a future definitive study. TRIAL REGISTRATION: ISRCTN Number 19701345. Date registered: 20/03/2023. URL: https://www.isrctn.com/ISRCTN19701345

Metagenomic characterisation of the gut microbiome and effect of complementary feeding on bifidobacterium spp. in Australian infants

Complementary feeding induces dramatic ecological shifts in the infant gut microbiota toward more diverse compositions and functional metabolic capacities, with potential implications for immune and metabolic health. The aim of this study was to examine whether the age at which solid foods are introduced differentially affects the microbiota in predominantly breastfed infants compared with predominantly formula-fed infants. We performed whole-genome shotgun metagenomic sequencing of infant stool samples from a cohort of six-month-old Australian infants enrolled in a nested study within the ORIGINS Project longitudinal birth cohort. Infants born preterm or those who had been administered antibiotics since birth were excluded. The taxonomic composition was highly variable among individuals at this age. Predominantly formula-fed infants exhibited a higher microbiome diversity than predominantly breastfed infants. Among the predominantly breastfed infants, the introduction of solid foods prior to five months of age was associated with higher alpha diversity than solid food introduction after six months of age, primarily due to the loss of Bifidobacterium infantis. In contrast, the age at which solid food was introduced was not associated with the overall change in diversity among predominantly formula-fed infants but was associated with compositional changes in Escherichia abundance. Examining the functional capacity of the microbiota in relation to these changes, we found that the introduction of solid foods after six months of age was associated with elevated one-carbon compound metabolic pathways in both breastfed and formula-fed infants, although the specific metabolic sub-pathways differed, likely reflecting different taxonomic compositions. Our findings suggest that the age of commencement of solid foods influences the gut microbiota composition differently in predominantly breastfed infants than in predominantly formula-fed infants

The applicability of FIR fine-structure lines as Star Formation Rate tracers over wide ranges of metallicities and galaxy types

We analyze the applicability of far-infrared fine-structure lines [CII] 158 micron, [OI] 63 micron and [OIII] 88 micron to reliably trace the star formation rate (SFR) in a sample of low-metallicity dwarf galaxies from the Herschel Dwarf Galaxy Survey and compare with a broad sample of galaxies of various types and metallicities in the literature. We study the trends and scatter in the relation between the SFR (as traced by GALEX FUV and MIPS 24 micron) and far-infrared line emission, on spatially resolved and global galaxy scales, in dwarf galaxies. We assemble far-infrared line measurements from the literature and infer whether the far-infrared lines can probe the SFR (as traced by the total-infrared luminosity) in a variety of galaxy populations. In metal-poor dwarfs, the [OI] and [OIII] lines show the strongest correlation with the SFR with an uncertainty on the SFR estimates better than a factor of 2, while the link between [CII] emission and the SFR is more dispersed (uncertainty factor of 2.6). The increased scatter in the SFR-L([CII]) relation towards low metal abundances, warm dust temperatures, large filling factors of diffuse, highly ionized gas suggests that other cooling lines start to dominate depending on the density and ionization state of the gas. For the literature sample, we evaluate the correlations for a number of different galaxy populations. The [CII] and [OI] lines are considered to be reliable SFR tracers in starburst galaxies, recovering the star formation activity within an uncertainty of factor 2. [Abridged]Comment: 35 pages, 13 figures, accepted for publication in A&A on May 7th 201