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We study the quantum gravity modification of the Kuroda–Papapetrou model induced by the running of the Newton’s constant at high energy in quantum Einstein gravity. We argue that although the antiscreening character of the gravitational interaction favours the formation of a naked singularity, quantum gravity effects turn the classical singularity into a ‘whimper’ singularity which remains naked for a finite amount of advanced time. [ABSTRACT FROM AUTHOR]

We use 2H NMR to investigate the segmental motion of poly(ethylene oxide) (PEO) in neat and nanocomposite materials that do and do not contain salt. Specifically, in addition to a neat low-molecular-weight PEO, we study mixtures of this polymer with TiO 2nanoparticles and LiClO 4. To characterize the polymer dynamics over a wide range of time scales, we combine 2H NMR spin−lattice relaxation, line-shape, and stimulated-echo analyses. The results consistently show that the presence of nanoparticles hardly affects the behavior of the polymer, while addition of salt leads to substantial changes; e.g., it reduces the crystallinity. For neat PEO and a PEO−TiO 2mixture, stimulated-echo spectroscopy enables measurement of rotational correlation functions for the crystalline phase. Analysis of the decays allows us to determine correlation times, to demonstrate the existence of a nonexponential relaxation, which implies a high complexity of the polymer dynamics in the crystal, and to show that the reorientation can be described as a large-angle jump. For a PEO−TiO 2−LiClO 4mixture, we use 2H and 7Li NMR to study the polymer and the lithium dynamics, respectively. Analysis of the 7Li spin−lattice relaxation reveals a high lithium ionic mobility in this nanocomposite polymer electrolyte. The 7Li stimulated-echo decay is well described by a stretched exponential extending over about 6 orders of magnitude, indicating that a broad and continuous distribution of correlation times characterizes the fluctuations of the local lithium ionic environments. [ABSTRACT FROM AUTHOR]

Abstract  Researchers from Colorado State University, in collaboration with scientists from the United States Department of Agriculture (USDA), initiated a long-term multi-disciplinary study in precision agriculture in 1997. Site-specific management zones (SSMZ) were investigated as a means of improving nitrogen management in irrigated maize cropping systems. The objective was to develop precise nutrient management strategies for semi-arid irrigated cropping systems. This study was conducted in five fields in northeastern Colorado, USA. Two techniques for delineating management zones were developed and compared: SSMZ and yield-based management zones (YBMZ). Nitrogen uptake and grain yield differences among SSMZs were compared as were soil properties. Both management zone techniques were used to divide fields into smaller units that were different with regard to productivity potential (e.g., high zones had high productivity potential while low zones had low productivity potential). Economic analysis was also performed. Based on grain yield productivity, the SSMZs performed better than the YBMZ technique in most cases. Grain yield and N uptake between the low and high productivity management zones were statistically different for most site-years and N fertilizer rates (p −1. In two out of three site-years the variable yield goal strategy resulted in the largest net returns. In this study, the SSMZ approach delineates areas of different productivity accurately across the agricultural fields. The SSMZs are different with regard to soil properties as well as grain yield and N uptake. Site-specific management zones are an inexpensive and pragmatic approach to precise N management in irrigated maize. [ABSTRACT FROM AUTHOR]

Edge localized mode (ELM) measurements in many tokamaks, including ASDEX-Upgrade, DIII-D, JET, JT-60U and MAST, are reviewed, which includes progress in experimental observations at the plasma edge region by means of fast-time resolved diagnostics with high precision, such as scanning probe, radial interferometer chord, BES and tangentially viewing fast-gated camera at the midplane. ELM dynamics data show that the majority of the ELM particle and energy transport should be dominated by ion convection physics and associated timescales. Furthermore, recent diagnostic upgrades on many tokamaks reveal the ELM filament structure and their complex motion towards radial, poloidal and toroidal directions. Approaches to control the Type-I ELMs, in addition to the alternative scenarios to Type-I ELMy H-mode operation (so-called, small/no ELM regimes) are also a key area of research for current tokamaks, which demonstrated a high confinement (being comparable to that of Type-I ELMy H-mode plasmas at similar parameters) in the absence of large, ELM induced, transient heat/particle fluxes to the divertor targets. Although tolerable ELM regimes are obtained in existing devices, their application to ITER is uncertain. Issues of these regimes towards further experiments and power deposition on divertor targets and main chamber wall are discussed. [ABSTRACT FROM AUTHOR]

Objective: To describe how a risk analysis can be applied to food fortification, with emphasis on voluntary fortification and intake levels that might exceed usual dietary levels. Design: Use of the risk analysis model as a frame to classify nutrients according to the risk of exceeding upper safe intake levels. Furthermore, to apply the model when discussing possible consequences of liberal fortification practices on eating behaviour and disease patterns. Setting: The discussion on food fortification presently going on internationally. Results: Micronutrients can be classified according to their safety margin, i.e. the size of the interval between the recommended intake and the upper safe level of intake. We suggest that nutrients with a small safety margin, i.e. for which the upper safe level is less than five times the recommended intake, be placed in a category A and should be handled with care (retinol, vitamin D, niacin, folate and all minerals). Category B comprises nutrients with an intermediate safety margin (vitamins E, B6, B12 and C), while nutrients that according to present knowledge are harmless even at 100 times the recommendation (vitamin K, thiamin, riboflavin, pantothenic acid and biotin) are categorised as C. Discussion: The risk analysis model is a useful tool when assessing the risk of both too low and excess intakes of single micronutrients, but can also be applied to analyse the consequences of fortification practices on eating behaviour and disease patterns. Liberal fortification regulations may, for example, distort the conception of what is healthy food, and drive consumption towards a more unhealthy diet, contributing to the plague of overweight and concomitant increased risk of degenerative diseases. Conclusion: The impact of fortification practices on the total eating pattern of a population should become an integrated part of the discussions and regulations connected to the issue. [ABSTRACT FROM AUTHOR]

Background: Renal impairment (RI) has been shown to be one major risk factor in a number of diseases and is associated with a dismal clinical outcome. However, the influence of milder degrees of renal disease is less well defined, particularly not in patients with malignant diseases. Patients and methods: We analyzed 167 patients with solid tumors and hematological malignancies. Besides disease-specific parameters, serum creatinine, cystatin C and the estimated glomerular filtration rate (eGFR) [‘modification of diet in renal disease’ equation (MDRD)/Cockcroft-Gault (CG)] were determined. Patients were compared within eGFR, creatinine and cystatin C groups. Results: The median MDRD, CG, creatinine and cystatin C levels of all patients were 88 ml/min/1.73 m2, 89 ml/min, 1 mg/dl and 0.9 mg/l, respectively. Patients with chronic kidney disease stage 2 still showed normal creatinine and cystatin levels of 1 mg/dl and 1.1 mg/l, respectively, although mild RI was frequent. Those cancer patients with decreased eGFR (MDRD) (<60 ml/min/1.73 m2) had increased odds ratios (ORs) to have more concurrent diagnoses [OR 3.4; 95% confidence interval (CI) 1.5–8.1], a body mass index >24 kg/m2 (OR 2.1; 95% CI 1.0–4.5) and an elevated (>245 pg/ml) pro-brain natriuretic peptide level (proBNP) (OR 9.2; 95% CI 3.0–28.3). Conclusions: These observations suggest that grouping cancer patients according to renal function, especially eGFR, may be one way to determine specific risk groups. [ABSTRACT FROM AUTHOR]