Application of processed organic municipal solid waste on agricultural land - a scenario analysis

Source separation, composting and anaerobic digestion, with associated land application, are increasingly being considered as alternative waste management strategies to landfilling and incineration of municipal solid waste (MSW). Environmental life cycle assessments are a useful tool in political decision-making about waste management strategies. However, due to the diversity of processed organic MSW and the situations in which it can be applied, the environmental impacts of land application are very hard to determine by experimental means. In the current study, we used the agroecosystem model Daisy to simulate a range of different scenarios representing different geographical areas, farm and soil types under Danish conditions and legislation. Generally, the application of processed organic MSW resulted in increased emissions compared with the corresponding standard scenarios, but with large differences between scenarios. Emission coefficients for nitrogen leaching to the groundwater ranged from 0.03 to 0.87, while those for nitrogen lost to surface waters through tile drains ranged from 0 to 0.30. Emission coefficients for N2O formation ranged from 0.013 to 0.022 and for ammonia volatilization from 0.016 to 0.11. These estimates are within reasonable range of observed values under similar conditions. Furthermore, a sensitivity analysis showed that the estimates were not very sensitive to the mineralization dynamics of the processed organic MSW. The results show that agroecosystem models can be powerful tools to estimate the environmental impacts of land application of processed MSW under different conditions. Despite this, agroecosystem models have only been used to a very limited degree for this purpose

Toward optimal X-ray flux utilization in breast CT

A realistic computer-simulation of a breast computed tomography (CT) system and subject is constructed. The model is used to investigate the optimal number of views for the scan given a fixed total X-ray fluence. The reconstruction algorithm is based on accurate solution to a constrained, TV-minimization problem, which has received much interest recently for sparse-view CT data.Comment: accepted to the 11th International Meeting on Fully Three-Dimensional Image Reconstruction in Radiology and Nuclear Medicine 201

Physics of the interior of a spherical, charged black hole with a scalar field

We analyse the physics of nonlinear gravitational processes inside a spherical charged black hole perturbed by a self-gravitating massless scalar field. For this purpose we created an appropriate numerical code. Throughout the paper, in addition to investigation of the properties of the mathematical singularities where some curvature scalars are equal to infinity, we analyse the properties of the physical singularities where the Kretschmann curvature scalar is equal to the planckian value. Using a homogeneous approximation we analyse the properties of the spacetime near a spacelike singularity in spacetimes influenced by different matter contents namely a scalar field, pressureless dust and matter with ultrarelativistic isotropic pressure. We also carry out full nonlinear analyses of the scalar field and geometry of spacetime inside black holes by means of an appropriate numerical code with adaptive mesh refinement capabilities. We use this code to investigate the nonlinear effects of gravitational focusing, mass inflation, matter squeeze, and these effects dependence on the initial boundary conditions. It is demonstrated that the position of the physical singularity inside a black hole is quite different from the positions of the mathematical singularities. In the case of the existence of a strong outgoing flux of the scalar field inside a black hole it is possible to have the existence of two null singularities and one central $r=0$ singularity simultaneously

Imaging Neurodegenerative Metabolism in Amyotrophic Lateral Sclerosis with Hyperpolarized [1-13C]pyruvate MRI

The cause of amyotrophic lateral sclerosis (ALS) is still unknown, and consequently, early diagnosis of the disease can be difficult and effective treatment is lacking. The pathology of ALS seems to involve specific disturbances in carbohydrate metabolism, which may be diagnostic and therapeutic targets. Magnetic resonance imaging (MRI) with hyperpolarized [1-(13)C]pyruvate is emerging as a technology for the evaluation of pathway-specific changes in the brain’s metabolism. By imaging pyruvate and the lactate and bicarbonate it is metabolized into, the technology is sensitive to the metabolic changes of inflammation and mitochondrial dysfunction. In this study, we performed hyperpolarized MRI of a patient with newly diagnosed ALS. We found a lateralized difference in [1-(13)C]pyruvate-to-[1-(13)C]lactate exchange with no changes in exchange from [1-(13)C]pyruvate to (13)C-bicarbonate. The 40% increase in [1-(13)C]pyruvate-to-[1-(13)C]lactate exchange corresponded with the patient’s symptoms and presentation with upper-motor neuron affection and cortical hyperexcitability. The data presented here demonstrate the feasibility of performing hyperpolarized MRI in ALS. They indicate potential in pathway-specific imaging of dysfunctional carbohydrate metabolism in ALS, an enigmatic neurodegenerative disease

Physics of the interior of a black hole with an exotic scalar matter

We use a numerical code to consider the nonlinear processes arising when a Reissner-Nordstrom black hole is irradiated by an exotic scalar field (modelled as a free massless scalar field with an opposite sign for its energy-momentum tensor). These processes are quite different from the processes arising in the case of the same black hole being irradiated by a pulse of a normal scalar field. In our case, we did not observe the creation of a spacelike strong singularity in the T-region of the space-time. We investigate the antifocusing effects in the gravity field of the exotic scalar field with the negative energy density and the evolution of the mass function. We demonstrate the process of vanishing of the black hole when it is irradiated by a strong pulse of an exotic scalar field.Comment: 16 pages, 16 figures. Text has been rewritten and restructured, Penrose diagrams have been added, appendix with convergence tests has been added. Co-author has been added. Conclusions are unchange

Lactate saturation limits bicarbonate detection in hyperpolarized 13 C-pyruvate MRI of the brain

PURPOSE: To investigate the potential effects of [1‐(13)C]lactate RF saturation pulses on [(13)C]bicarbonate detection in hyperpolarized [1‐(13)C]pyruvate MRI of the brain. METHODS: Thirteen healthy rats underwent MRI with hyperpolarized [1‐(13)C]pyruvate of either the brain (n = 8) or the kidneys, heart, and liver (n = 5). Dynamic, metabolite‐selective imaging was used in a cross‐over experiment in which [1‐(13)C]lactate was excited with either 0° or 90° flip angles. The [(13)C]bicarbonate SNR and apparent [1‐(13)C]pyruvate‐to‐[(13)C]bicarbonate conversion (k (PB)) were determined. Furthermore, simulations were performed to identify the SNR optimal flip‐angle scheme for detection of [1‐(13)C]lactate and [(13)C]bicarbonate. RESULTS: In the brain, the [(13)C]bicarbonate SNR was 64% higher when [1‐(13)C]lactate was not excited (5.8 ± 1.5 vs 3.6 ± 1.3; 1.2 to 3.3–point increase; p = 0.0027). The apparent k (PB) decreased 25% with [1‐(13)C]lactate saturation (0.0047 ± 0.0008 s(−1) vs 0.0034 ± 0.0006 s(−1); 95% confidence interval, 0.0006–0.0019 s(−1) increase; p = 0.0049). These effects were not present in the kidneys, heart, or liver. Simulations suggest that the optimal [(13)C]bicarbonate SNR with a TR of 1 s in the brain is obtained with [(13)C]bicarbonate, [1‐(13)C]lactate, and [1‐(13)C]pyruvate flip angles of 60°, 15°, and 10°, respectively. CONCLUSIONS: Radiofrequency saturation pulses on [1‐(13)C]lactate limit [(13)C]bicarbonate detection in the brain specifically, which could be due to shuttling of lactate from astrocytes to neurons. Our results have important implications for experimental design in studies in which [(13)C]bicarbonate detection is warranted

Dynamic study of carbon nanotube growth and catalyst morphology evolution during acetylene decomposition on Co/SBA-15 in an environmental TEM

International @ SURFACES+FCA:MAO:ATUInternational audienceNon

Rift Valley fever in Kenyan pastoral livestock: Individual-based demographic model to analyse the impact of Rift Valley fever

Background Rift Valley Fever (RVF) is a viral zoonosis and a mosquito-borne disease caused by a phlebovirus in the family Bunyaviridae. It affects livestock, humans and wildlife. Epidemic outbreaks of RVF in East Africa, which occur after heavy rainfalls in cycles of 5-15 years, have caused next to human morbidity and mortality considerable economic losses throughout the livestock production and market chain. Objective Establishment a pastoral livestock demographic model to simulate 10 year alternating normal and drought periods and RVF epidemics. Methods We developed an individual-based C++ language with Borland C++ builder 6 model, to simulate livestock dynamics in North Eastern-Province during normal and drought periods, tracked over days and years. During RVF epidemics and with different control measures, animals were stratified into susceptible, exposed, infectious and recovered. The following scenarios were modeled (i) the demographic dynamics of cattle, camels, sheep and goats; (ii) an RVF outbreak in livestock and (iii) impacts of control measures (combinations of vaccination, sanitary measures, surveillance and vector control). Results/Conclusions Sheep and goat populations increase fastest (9-23%) annually during normal years while cattle and sheep populations show fastest decline during drought. In infected areas, mainly sheep (59%) are infected followed by goats (44%), cattle (31%), and camels (5%). Sheep and goats are most likely to spread the RVF through livestock trade. Slaughtered infected sheep are an important risk factor to human RVF infection. After the 2006/2007 outbreak, 2%, 40%, 30% and less than 1% of cattle, sheep, goats and camels acquired immunity. After seven years, only 4%, of sheep and goats remain immune. Our results will assist in the assessment of cost-benefit and cost-effectiveness of interventions which should improve future intersectoral livestock – public health contingency planning

A new class of IMP dehydrogenase with a role in self-resistance of mycophenolic acid producing fungi

<p>Abstract</p> <p>Background</p> <p>Many secondary metabolites produced by filamentous fungi have potent biological activities, to which the producer organism must be resistant. An example of pharmaceutical interest is mycophenolic acid (MPA), an immunosuppressant molecule produced by several <it>Penicillium </it>species. The target of MPA is inosine-5'-monophosphate dehydrogenase (IMPDH), which catalyses the rate limiting step in the synthesis of guanine nucleotides. The recent discovery of the MPA biosynthetic gene cluster from <it>Penicillium brevicompactum </it>revealed an extra copy of the IMPDH-encoding gene (<it>mpaF</it>) embedded within the cluster. This finding suggests that the key component of MPA self resistance is likely based on the IMPDH encoded by <it>mpaF</it>.</p> <p>Results</p> <p>In accordance with our hypothesis, heterologous expression of <it>mpaF </it>dramatically increased MPA resistance in a model fungus, <it>Aspergillus nidulans</it>, which does not produce MPA. The growth of an <it>A. nidulans </it>strain expressing <it>mpaF </it>was only marginally affected by MPA at concentrations as high as 200 μg/ml. To further substantiate the role of <it>mpaF </it>in MPA resistance, we searched for <it>mpaF </it>orthologs in six MPA producer/non-producer strains from <it>Penicillium </it>subgenus <it>Penicillium</it>. All six strains were found to hold two copies of IMPDH. A cladistic analysis based on the corresponding cDNA sequences revealed a novel group constituting <it>mpaF </it>homologs. Interestingly, a conserved tyrosine residue in the original class of IMPDHs is replaced by a phenylalanine residue in the new IMPDH class.</p> <p>Conclusions</p> <p>We identified a novel variant of the IMPDH-encoding gene in six different strains from <it>Penicillium </it>subgenus <it>Penicillium</it>. The novel IMPDH variant from MPA producer <it>P. brevicompactum </it>was shown to confer a high degree of MPA resistance when expressed in a non-producer fungus. Our study provides a basis for understanding the molecular mechanism of MPA resistance and has relevance for biotechnological and pharmaceutical applications.</p