Agricultural Pollution of Water Bodies

Pollution of Ohio's water bodies is of growing public concern; industrial, urban, and rural sources are becoming the subject of critical examination. Rural sources are soil sediment, plant nutrients, animal waste, and pesticides. Pesticides and phosphorus are absorbed rapidly and strongly to soil particles. Therefore reductions in sediment, phosphorus, and pesticide pollution are achieved by soil-erosion-control farming practices. More acres need to be brought under erosion-control practices. Nitrates dissolve in water and are carried by surface flow to streams and lakes, and by percolating water to underground aquifers. Increases in the use of nitrogen fertilizer, in evidence almost everywhere, could result in serious contamination of water bodies, if soil enrichment greatly exceeds the crop demand. Areas where large-scale livestock and poultry production is concentrated are also potential sources of serious pollution. In Ohio, animalwaste pollution problems are being studied at The Ohio State University, and movement of pollutants in surface and subsurface waters on drainage plots near Castalia are being studied by the Ohio Agricultural Research and Development Center and on agricultural watersheds by USDA Agricultural Research Service at Coshocton, Ohio

Analysis of array spacing on tidal stream turbine farm performance using Large-Eddy Simulation

This is the final version. Available on open access from Elsevier via the DOI in this recordData availability Information on the data underpinning the results presented here, including how to access them, can be found in the Cardiff University data catalogue at 10.17035/d.2019.0083917166Design of efficient tidal arrays relies on the adopted spacing between turbines and their mutual interplay. Turbines affected by wake shadowing operate in harsher flow conditions, such as higher turbulence levels or lower incident velocity, which leads to reduced performance and larger extreme and fatigue loading. To extend the knowledge about turbine-to-turbine interplay in tidal arrays, high-fidelity numerical simulations using a Large-Eddy Simulation-Actuator Line Method (LES-ALM) are carried out to quantify the impact of row spacing. The developed Digital Offshore FArm Simulator (DOFAS) validates well with experimental data in terms of flow statistics and hydrodynamic coefficients, which demonstrate its adequacy to resolve the complex fluid-turbines interaction. In the cases with spacing of four and eight diameters between the rows, the lack of wake recovery has a detrimental effect on back-row turbines whose efficiency dramatically drops compared to those in the front-row. The LES-ALM captured the low-frequency wake meandering phenomenon responsible for uneven periodic loading on back-row turbines. The devices placed in the front-row suffer the largest thrust loads, blade-root bending moments and support structure moments, whilst the outermost back-row turbines experience the largest tower yaw moments due to their simultaneous exposure to low-momentum turbulent wakes and high-velocity free-stream flow. Finally, damage equivalent loads estimated by the LES-ALM are maximum for the front-row turbines except the tower yaw moment which is maximum on the outermost back-row turbines.Engineering and Physical Sciences Research Council (EPSRC)Ministerio de Ciencia, Innovación y Universidades of the Spanish Governmen

Clinical review: Early patient mobilization in the ICU

Early mobilization (EM) of ICU patients is a physiologically logical intervention to attenuate critical illness-associated muscle weakness. However, its long-term value remains controversial. We performed a detailed analytical review of the literature using multiple relevant key terms in order to provide a comprehensive assessment of current knowledge on EM in critically ill patients. We found that the term EM remains undefined and encompasses a range of heterogeneous interventions that have been used alone or in combination. Nonetheless, several studies suggest that different forms of EM may be both safe and feasible in ICU patients, including those receiving mechanical ventilation. Unfortunately, these studies of EM are mostly single center in design, have limited external validity and have highly variable control treatments. In addition, new technology to facilitate EM such as cycle ergometry, transcutaneous electrical muscle stimulation and video therapy are increasingly being used to achieve such EM despite limited evidence of efficacy. We conclude that although preliminary low-level evidence suggests that EM in the ICU is safe, feasible and may yield clinical benefits, EM is also labor-intensive and requires appropriate staffing models and equipment. More research is thus required to identify current standard practice, optimal EM techniques and appropriate outcome measures before EM can be introduced into the routine care of critically ill patients

Discovery of an ultramassive pulsating white dwarf

We announce the discovery of the most massive pulsating hydrogen-atmosphere (DA) white dwarf (WD) ever discovered, GD 518. Model atmosphere fits to the optical spectrum of this star show it is a 12,030 +/- 210 K WD with a log(g) = 9.08 +/- 0.06, which corresponds to a mass of 1.20 +/- 0.03 Msun. Stellar evolution models indicate that the progenitor of such a high-mass WD endured a stable carbon-burning phase, producing an oxygen-neon-core WD. The discovery of pulsations in GD 518 thus offers the first opportunity to probe the interior of a WD with a possible oxygen-neon core. Such a massive WD should also be significantly crystallized at this temperature. The star exhibits multi-periodic luminosity variations at timescales ranging from roughly 425-595 s and amplitudes up to 0.7%, consistent in period and amplitude with the observed variability of typical ZZ Ceti stars, which exhibit non-radial g-mode pulsations driven by a hydrogen partial ionization zone. Successfully unraveling both the total mass and core composition of GD 518 provides a unique opportunity to investigate intermediate-mass stellar evolution, and can possibly place an upper limit to the mass of a carbon-oxygen-core WD, which in turn constrains SNe Ia progenitor systems.Comment: 5 pages, 3 figures, Astrophysical Journal Letters, 771, L2 (2013

Correcting for the overabundance of low-mass quiescent galaxies in semi-analytic models

© 2024 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/We compare the l-galaxies semi-analytic model to deep observational data from the UKIDSS Ultra Deep Survey (UDS) across the redshift range 0.5 \lt; z \lt; 3. We find that the overabundance of low-mass, passive galaxies at high redshifts in the model can be attributed solely to the properties of ‘orphan’ galaxies, i.e. satellite galaxies where the simulation has lost track of the host dark matter sub-halo. We implement a simple model that boosts the star formation rates in orphan galaxies by matching them to non-orphaned satellite galaxies at a similar evolutionary stage. This straightforward change largely addresses the discrepancy in the low-mass passive fraction across all redshifts. We find that the orphan problem is somewhat alleviated by higher resolution simulations, but the preservation of a larger gas reservoir in orphans is still required to produce a better fit to the observed space density of low-mass passive galaxies. Our findings are also robust to the precise definition of the passive galaxy population. In general, considering the vastly different prescriptions used for orphans in semi-analytic models, we recommend that they are analysed separately from the resolved satellite galaxy population, particularly with JWST observations reigniting interest in the low-mass regime in which they dominate.Peer reviewe

Discovery of pulsations, including possible pressure modes, in two new extremely low mass, He-core white dwarfs

We report the discovery of the second and third pulsating extremely low mass white dwarfs (WDs), SDSS J111215.82+111745.0 (hereafter J1112) and SDSS J151826.68+065813.2 (hereafter J1518). Both have masses < 0.25 Msun and effective temperatures below 10,000 K, establishing these putatively He-core WDs as a cooler class of pulsating hydrogen-atmosphere WDs (DAVs, or ZZ Ceti stars). The short-period pulsations evidenced in the light curve of J1112 may also represent the first observation of acoustic (p-mode) pulsations in any WD, which provide an exciting opportunity to probe this WD in a complimentary way compared to the long-period g-modes also present. J1112 is a Teff = 9590 +/- 140 K and log(g) = 6.36 +/- 0.06 WD. The star displays sinusoidal variability at five distinct periodicities between 1792-2855 s. In this star we also see short-period variability, strongest at 134.3 s, well short of expected g-modes for such a low-mass WD. The other new pulsating WD, J1518, is a Teff = 9900 +/- 140 K and log(g) = 6.80 +/- 0.05 WD. The light curve of J1518 is highly non-sinusoidal, with at least seven significant periods between 1335-3848 s. Consistent with the expectation that ELM WDs must be formed in binaries, these two new pulsating He-core WDs, in addition to the prototype SDSS J184037.78+642312.3, have close companions. However, the observed variability is inconsistent with tidally induced pulsations and is so far best explained by the same hydrogen partial-ionization driving mechanism at work in classic C/O-core ZZ Ceti stars.Comment: 9 pages, 5 figures, accepted to The Astrophysical Journa

Real-world Comparative Effectiveness of Tocilizumab Monotherapy vs. Tumor Necrosis Factor Inhibitors with Methotrexate in Patients with Rheumatoid Arthritis

INTRODUCTION: Controlled clinical studies have shown that the efficacy of tocilizumab (TCZ) monotherapy is superior to that of tumor necrosis factor inhibitor (TNFi) monotherapy and comparable to that of TCZ plus methotrexate (MTX) for the treatment of rheumatoid arthritis (RA). This study compared the real-world effectiveness of TCZ monotherapy vs. TNFis plus MTX in US patients with RA. METHODS: TCZ-naive patients from the Corrona RA registry with prior exposure to \u3e /= 1 TNFi who initiated TCZ monotherapy or TNFi + MTX were included. Outcomes included mean change in Clinical Disease Activity Index (CDAI), achievement of low disease activity (LDA; CDAI \u3c /= 10), achievement of modified American College of Rheumatology (mACR) 20/50 responses, and mean change in modified Health Assessment Questionnaire (mHAQ) at 6 months. Patients initiating TNFi + MTX were grouped by MTX dose ( \u3c /= 10 mg; \u3e 10 to \u3c /= 15 mg; \u3e 15 to \u3c /= 20 mg; \u3e 20 mg); outcomes in each group were compared with TCZ monotherapy using trimmed populations (excluding patients outside the propensity score distribution overlap). RESULTS: Patients in all groups experienced improvement in CDAI at 6 months (mean change, - 6.9 to - 9.7), with no significant differences between the TCZ monotherapy and TNFi + MTX groups. Achievement of LDA and mACR responses at 6 months were comparable between the TCZ monotherapy and TNFi + MTX groups; overall, 26.8-38.0% of patients achieved LDA, 24.3-37.6% achieved mACR20 response and 13.2-20.8% achieved mACR50 response. The mean change in mHAQ at 6 months was - 0.1 in all groups. CONCLUSIONS: In this real-world population of US patients with RA who had prior TNFi exposure, there was no evidence of a difference in the effectiveness of TCZ monotherapy compared with that of TNFi + MTX, regardless of MTX dose, at 6 months for improving RA disease activity. FUNDING: Corrona, LLC. Plain language summary available for this article

What have human experimental overfeeding studies taught us about adipose tissue expansion and susceptibility to obesity and metabolic complications?

Overfeeding experiments, in which we impose short-term positive energy balance, help unravel the cellular, physiological and behavioural adaptations to nutrient excess. These studies mimic longer-term mismatched energy expenditure and intake. There is considerable inter-individual heterogeneity in the magnitude of weight gain when exposed to similar relative caloric excess reflecting variable activation of compensatory adaptive mechanisms. Significantly, given similar relative weight gain, individuals may be protected from/predisposed to metabolic complications (insulin resistance, dyslipidaemia, hypertension), non-alcoholic fatty liver disease and cardiovascular disease. Similar mechanistic considerations underpinning the heterogeneity of overfeeding responses are pertinent in understanding emerging metabolic phenotypes, for example, metabolically unhealthy normal weight and metabolically healthy obesity. Intrinsic and extrinsic factors modulate individuals’ overfeeding response: intrinsic factors include gender/hormonal status, genetic/ethnic background, baseline metabolic health and cardiorespiratory fitness; extrinsic factors include macronutrient (fat vs carbohydrate) content, fat/carbohydrate composition and overfeeding pattern. Subcutaneous adipose tissue (SAT) analysis, coupled with metabolic assessment, with overfeeding have revealed how SAT remodels to accommodate excess nutrients. SAT remodelling occurs either by hyperplasia (increased adipocyte number) or by hypertrophy (increased adipocyte size). Biological responses of SAT also govern the extent of ectopic (visceral/liver) triglyceride deposition. Body composition analysis by DEXA/MRI (dual energy X-ray absorptiometry/magnetic resonance imaging) have determined the relative expansion of SAT (including abdominal/gluteofemoral SAT) vs ectopic fat with overfeeding. Such studies have contributed to the adipose expandability hypothesis whereby SAT has a finite capacity to expand (governed by intrinsic biological characteristics), and once capacity is exceeded ectopic triglyceride deposition occurs. The potential for SAT expandability confers protection from/predisposes to the adverse metabolic responses to overfeeding. The concept of a personal fat threshold suggests a large inter-individual variation in SAT capacity with ectopic depot expansion/metabolic decompensation once one’s own threshold is exceeded. This review summarises insight gained from overfeeding studies regarding susceptibility to obesity and related complications with nutrient excess