Linking soil moisture status of winter sports pitches to measures of playing quality

A review of traction and hardness Performance Quality Standard tests highlighted significant relationships with soil and grass factors. Inadequate guidance to achieve test results through pitch management means that management practices can not focus on injury prevention or playing quality. A clear link between factors that can be managed by Groundsmen and the traction and hardness tests is required. The concept of effective stress significantly linked moisture status to soil strength in the laboratory. Penetration resistance was shown to be complex and affected by grass roots and bulk density, which prevented a single model encompassing all soil types to be established. Prediction of traction and hardness used grass and soil factors and varied according to soil type and wet or dry test conditions. In situ tests showed no variation due to pitch test position and as sand content increased, prediction became less reliable. A decision support model used the regression results to provide Groundsmen with the ability to monitor pitch quality in real-time. Effective stress successfully linked moisture status and strength although in situ verification is required. Regression analysis and the decision support model will assist Groundsmen in managing pitches while targeting playing quality. Further research to understand how management practices impact on quality and to understand the link between injury rates and type, and the results of traction and hardness tests is required. This knowledge will enable a company to simultaneously differentiate itself from competition and create a barrier to potential entrants.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Water table control for rice production in Ghana

An investigation has been undertaken to determine the consequence of using water table control for lowland rice production by growing rice varieties Azucena and IR36 in sand cores under a controlled environment in a series of experiments in which the water table was held at fixed levels. Each experiment had a duration of six weeks and in all, four treatments were used: (a) water table at a depth of 30 cm below the surface, (b) water table at a depth of 15 cm below the surface, (c) saturated sand and (c) flooded sand. Growth under the two water table depths compared favourably with the flooded and saturated conditions, with plants under the water table control treatments in some cases performing better in terms of plant performance than the saturated or flooded. Plant growth parameters measured were: Tiller number, root dry mass, shoot dry mass, rooting depth, total root length and plant height. Other parameters measured are: Solution nitrogen concentration, redox potential, growth medium temperature and pH levels. When IR36 was used the total root length, number of roots and tiller numbers were significantly greater for the plants in the saturated treatment but there were no significant differences in root mass, shoot mass, and shoot length with regards to water depth. When Azucena variety was used, the 15 cm treatment had the highest shoot mass in addition to the highest tiller numbers. In other parameters, the 15 cm treatment did not show a significant difference to the saturated treatment. The 30 cm treatment performed least well in all parameters measured. Plants under the flooded treatment had a significantly greater root dry mass, shoot dry mass and tiller number than the others. The plants grown under 15 cm water table depth had the least root mass. Tiller numbers for the plants under the 30 cm water table depth were greater than those under the 15 cm water table depth. Differences in plant development parameters generally appeared only after the fourth week. The data suggest that irrespective of the water treatment used, plant development trends remain the same indicating that in the first four weeks of rice growth much less water can be used without affecting plant development. Where Azucena and IR36 were both used the data suggest that water table control might be suitable for both varieties of rice. Differences in the amount of nitrogen present were seen to have had an impact on growth. Varying the form of nitrogen applied did not alter growth parameters to any appreciable extent implying that supply of nitrogen is more important than the form of nitrogen used. The effect of root properties and NH4+ transport through the soil on N uptake under different water regimes has been modelled. The model adequately predicted the root length densities required to explain N uptake rates. It is shown that root length densities increase with decreasing moisture content, allowing larger root length densities to compensate for low nutrient transport rates and although diffusion of nutrients increased with increasing moisture levels, nutrient uptake rates did not follow the same pattern. Rooting length densities and transport of nutrients are not shown to limit uptake of nutrients under any of the water treatments imposed. The feasibility of using water table control in the inland valleys of Ghana was also investigated by simulating the depth of the water table required in the dry season of the years 1996 and 1997. A comparison of water use under water table control and flooding irrigation showed that water savings were possible suggesting that water table control is feasible and beneficial in the inland valleys of Ghana.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Rhizosphere-scale quantification of hydraulic and mechanical properties of soil impacted by root and seed exudates

Using rhizosphere-scale physical measurements we test the hypothesis that plant exudates gel together soil particles and on drying they enhance soil water repellency. Barley and maize root exudates were compared with chia seed exudate, a commonly used root exudate analogue. Sandy loam and clay loam soils were treated with root exudates at 0.46 and 4.6 mg exudate g-1 dry soil, and chia seed exudate at 0.046, 0.46, 0.92, 2.3 and 4.6 mg exudate g-1 dry soil. Soil hardness and modulus of elasticity were measured at -10 kPa matric potential using a 3 mm diameter spherical indenter. Water sorptivity and repellency index of air-dry soil were measured using a miniaturized infiltrometer device with a 1 mm tip radius. Soil hardness increased by 28% for barley root exudate, 62% for maize root exudate, and 86% for chia seed exudate at 4.6 mg g-1 concentration for sandy loam soil. For a clay loam soil, root exudates did not affect soil hardness, whereas chia seed exudate increased soil hardness by 48% at 4.6 mg g-1concentration. Soil water repellency increased by 48% for chia seed exudate and 23% for maize root exudate, but not for barley root exudate at 4.6 mg g-1 concentration for sandy loam soil. For clay loam soil, chia seed exudate increased water repellency by 45%, whereas root exudates did not affect water repellency at 4.6 mg g-1concentration. Water sorptivity and repellency were both correlated with hardness, presumably due to the combined influence of exudates on hydrological and mechanical properties of soils

Impact of Nonsense-Mediated mRNA Decay on the Global Expression Profile of Budding Yeast

Nonsense-mediated mRNA decay (NMD) is a eukaryotic mechanism of RNA surveillance that selectively eliminates aberrant transcripts coding for potentially deleterious proteins. NMD also functions in the normal repertoire of gene expression. In Saccharomyces cerevisiae, hundreds of endogenous RNA Polymerase II transcripts achieve steady-state levels that depend on NMD. For some, the decay rate is directly influenced by NMD (direct targets). For others, abundance is NMD-sensitive but without any effect on the decay rate (indirect targets). To distinguish between direct and indirect targets, total RNA from wild-type (Nmd(+)) and mutant (Nmd(−)) strains was probed with high-density arrays across a 1-h time window following transcription inhibition. Statistical models were developed to describe the kinetics of RNA decay. 45% ± 5% of RNAs targeted by NMD were predicted to be direct targets with altered decay rates in Nmd(−) strains. Parallel experiments using conventional methods were conducted to empirically test predictions from the global experiment. The results show that the global assay reliably distinguished direct versus indirect targets. Different types of targets were investigated, including transcripts containing adjacent, disabled open reading frames, upstream open reading frames, and those prone to out-of-frame initiation of translation. Known targeting mechanisms fail to account for all of the direct targets of NMD, suggesting that additional targeting mechanisms remain to be elucidated. 30% of the protein-coding targets of NMD fell into two broadly defined functional themes: those affecting chromosome structure and behavior and those affecting cell surface dynamics. Overall, the results provide a preview for how expression profiles in multi-cellular eukaryotes might be impacted by NMD. Furthermore, the methods for analyzing decay rates on a global scale offer a blueprint for new ways to study mRNA decay pathways in any organism where cultured cell lines are available

The hybrid state: Crime and citizenship in urban Jamaica

In inner-city neighborhoods in Kingston, Jamaica, criminal "dons" have taken on a range of governmental functions. While such criminal actors have sometimes been imagined as heading "parallel states," I argue that they are part of a hybrid state, an emergent political formation in which multiple governmental actors—in this case, criminal organizations, politicians, police, and bureaucrats—are entangled in a relationship of collusion and divestment, sharing control over urban spaces and populations. Extending recent scholarship on variegated sovereignty and neoliberal shifts in governance, I consider the implications of this diversification of governmental actors for the ways that citizenship is experienced and enacted. The hybrid state both produces and relies on distinct political subjectivities. It is accompanied by a reconfigured, hybrid citizenship, in which multiple practices and narratives related to rule and belonging, to rights and responsibilities, are negotiated by a range of actors. - See more at: http://www.anthrosource.net/Abstract.aspx?issn=0094-0496&volume=40&issue=4&doubleissueno=0&article=339507&suppno=0&jstor=False&cyear=2013#sthash.6XmjPANm.dpu

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Removal of ammoniacal nitrogen from landfill leachate by irrigation onto vegetated treatment planes

Leachate is a contaminated liquor resulting from the disposal of solid and liquid wastes at landfill sites that must be treated before discharge. Vegetated leachate treatment planes have been used at landfill sites in the UK but have received little scientific attention. This paper describes studies of model leachate treatment planes with a focus on the removal of ammoniacal nitrogen (NH3-N). Small-scale and field-scale experimental treatment planes were constructed, filled with clay loam soil and vegetated with grass (Agrostis stolonifera). Landfill leachate was applied at hydraulic loading rates ranging from 17-217 l/m2/d. An exponential relationship was used to characterise the pattern of NH3-N removal. No relationship was observed between the hydraulic loading rate and the NH3-N removal rate constants (R2 = 0.0039). The daily specific NH3 -N mass removal rate was found to be linearly related to the NH3 -N concentration at the start of that day of treatment (R2 = 0.35). Possible causes of variation in the rate of NH3-N removal between experiments are discussed. A simple inorganic nitrogen balance indicated that the mass of NH3-N and NO2-N removed was not accounted for by NO3-N production. Explanations for this apparent nitrogen deficit are discussed

Grassed buffer strips for the control of nitrate leaching to surface waters in headwater catchments.

The use of riparian buffer strips is a possible strategy for controlling diffuse nitrate pollution of surface water in agricultural catchments. Data collected from paired buffered and unbuffered headwater catchments at three sites with conditions representative of much of the agricultural land in England and Wales, showed that grassed buffers did not substantially reduce nitrate–nitrogen concentrations entering the streams. Median nitrate–nitrogen levels observed in buffered catchments ranged from 7.6 to 18.8 mgN l−1, but peaked at up to 46.1 mgN l−1. The existence of preferential bypass flow paths during the winter flow events limited the effectiveness of nitrate removing processes within the strips. The findings suggest that grassed riparian buffer strips may not be effective in controlling diffuse nitrate pollution unless the hydrology of the strip allows a suitable environment for denitrification and/or plant uptake. Grassed buffer strips should be carefully targeted or, alternatively, engineered to ensure adequate residence time of solutes within the strip

Explicit stiffness matrices for triangular, plate bending finite elements

Explicit stiffness matrices are available for rectangular plate bending elements, rectangular plane stress and plane strain elements and triangular plane stress and plane strain elements. Triangular plate bending elements can at present only be formed by using a numeric algorithm. The explicit version of a stiffness matrix is not only far more simple to program in a computer routine but its execution (as will be shown) requires approximately one twelfth of the time of a numeric version. Rectangular plate bending elements do not have a compliant shape (see definition) so their use is limited to plates which in many cases can be solved by other methods. Judging from the number of attempts to find a successful triangular plate bending element, the simplicity of a triangular shape appeals to most investigators. In the present investigation only triangular elements with a node on each corner and three degrees of freedom at each node will be considered. Some investigators have included extra nodes on the edges and/or at the centroid of the triangle. This is done in order to overcome difficulties experienced in choosing a suitable displacement function for a nine degree of freedom triangle. Except for comparison of results (table 4) such elements will not be considered. An explicit stiffness matrix for a small deflection theory, elastic, isotropic, triangular plate bending element will be developed