PDEs in Moving Time Dependent Domains

In this work we study partial differential equations defined in a domain that moves in time according to the flow of a given ordinary differential equation, starting out of a given initial domain. We first derive a formulation for a particular case of partial differential equations known as balance equations. For this kind of equations we find the equivalent partial differential equations in the initial domain and later we study some particular cases with and without diffusion. We also analyze general second order differential equations, not necessarily of balance type. The equations without diffusion are solved using the characteristics method. We also prove that the diffusion equations, endowed with Dirichlet boundary conditions and initial data, are well posed in the moving domain. For this we show that the principal part of the equivalent equation in the initial domain is uniformly elliptic. We then prove a version of the weak maximum principle for an equation in a moving domain. Finally we perform suitable energy estimates in the moving domain and give sufficient conditions for the solution to converge to zero as time goes to infinity.Comment: pp 559-577. Without Bounds: A Scientific Canvas of Nonlinearity and Complex Dynamics (2013) p. 36

Utilization of tmRNA sequences for bacterial identification

In recent years, molecular approaches based on nucleotide sequences of ribosomal RNA (rRNA) have become widely used tools for identification of bacteria [1-4]. The high degree of evolutionary conservation makes 16S and 23S rRNA molecules very suitable for phylogenetic studies above the species level [3-5]. More than 16,000 sequences of 16S rRNA are presently available in public databases [4,6]. The 16S rRNA sequences are commonly used to design fluorescently labeled oligonucleotide probes. Fluorescence in situ hybridization (FISH) with these probes followed by observation with epifluorescence microscopy allows the identification of a specific microorganism in a mixture with other bacteria [2-4]. By shifting probe target sites from conservative to increasingly variable regions of rRNA, it is possible to adjust the probe specificity from kingdom to species level. Nevertheless, 16S rRNA sequences of closely related strains, subspecies, or even of different species are often identical and therefore can not be used as differentiating markers [3]. Another restriction concerns the accessibility of target sites to the probe in FISH experiments. The presence of secondary structures, or protection of rRNA segments by ribosomal proteins in fixed cells can limit the choice of variable regions as in situ targets for oligonucleotide probes [7,8]. One way to overcome the limitations of in situ identification of bacteria is to use molecules other than rRNA for phylogenetic identification of bacteria, for which nucleotide sequences would be sufficiently divergent to design species specific probes, and which would be more accessible to oligonucleotide probes. For this purpose we investigated the possibility of using tmRNA (also known as 10Sa RNA; [9-11]). This molecule was discovered in E. coli and described as small stable RNA, present at ~1,000 copies per cell [9,11]. The high copy number is an important prerequisite for FISH, which works best with naturally amplified target molecules. In E. coli, tmRNA is encoded by the ssrA gene, is 363 nucleotides long and has properties of tRNA and mRNA [12,13]. tmRNA was shown to be involved in the degradation of truncated proteins: the tmRNA associates with ribosomes stalled on mRNAs lacking stop codons, finally resulting in the addition of a C-terminal peptide tag to the truncated protein. The peptide tag directs the abnormal protein to proteolysis [14,15]. 165 tmRNA sequences have so far (August 2001; The tmRNA Website: http://www.indiana.edu/~tmrna/) been determined [16,17]. The tmRNA is likely to be present in all bacteria and has also been found in algae chloroplasts, the cyanelle of Cyanophora paradoxa and the mitochondrion of the flagellate Reclinomonas americana[10,17,18]

Cost Functions for Controlling SO2 Emissions in Europe

This paper marks an important step in the development of the Regional Acidification INformation and Simulation (RAINS) model. One of the major goals of the project since its beginning four years ago, has been to get RAINS used in policy analysis. To that end the model should include variables that are very crucial in the eyes of the decision makers. The cost of reducing air pollutant emissions certainly is such an important policy relevant variable. The authors have successfully developed a uniform approach for establishing cost-of-control functions for emissions of sulfur dioxide in virtually all European countries. This uniformity is particularly important for comparing the cost-effectiveness of various scenarios for controlling acid deposition in Europe. Currently the assumptions and the numbers in this paper are under review by experts in many of the European countries. The cost-of-control functions allow the evaluation of targeted deposition levels at a variety of locations in Europe. This will be the topic of a subsequent paper. In the near future we will also develop similar control function for the emissions of nitrogen oxides and will eventually combine the functions into one cost-of-control function for acidifying emissions

Cost-Effective Strategies for Reducing Nitrogen Deposition in Europe

This paper explores the potential cost savings which would result from a combined control of emissions of nitrogen oxides and ammonia for the cost-effective achievement of nitrogen deposition targets in Europe. Using the Regional Acidification INformation and Simulation (RAINS) model a framework has been constructed for a simultaneous optimization of NOx and NH3 emission reductions using nitrogen depositions from both pollutants as side constraints. The paper first demonstrates that the same nitrogen deposition resulting from the currently committed reductions of NOx emissions (without measures for NH3 emissions) can be achieved at only 55 percent of the costs if measures for ammonia reduction would also be applied. The analysis shows that no large scale substitutions of NO, reductions by ammonia measures occur. The cost savings mainly result from replacing the most expensive (and ineffective) NOx abatement at a few places in Europe with inexpensive ammonia control measures. Consequently, the total level of NOx emissions is hardly higher than in the reference case, but substantial NH3 reductions are implemented lowering total cost. The second case explores the potential contribution ammonia control can make for attaining the same nitrogen deposition levels resulting from the maximum application of NOx abatement technologies solely. In this case reductions of ammonia emissions can lower total abatement costs by 23 percent, basically by modified manure handling, stable adaptations for poultry and the control of industrial ammonia emissions

Trading of Emission Reduction Commitments for Sulfur Dioxide in Europe

This paper analyzes the potential role of emission trading systems for non-uniformly dispersed air pollutants, for which the geographical location of emissions has a significant impact on the location and extent of environmental damage. The paper derives the necessary conditions for trading schemes to be cost-effective and introduces the concept of offset rates. Offset rates describe the amount of emissions one source has to decrease if another source increases its emissions by one unit. To explore the potential performance of alternative trading schemes a simulation framework based on' the IIASA-RAINS model has been developed. Simulation runs to achieve regionally specified maximum levels of sulfur deposition (target loads) in Europe show that trading may result in cost savings. The extent to which such cost savings are possible and whether the originally specified target deposition levels are exceeded, depends crucially on the pre-trade level of emissions, the availability of information on costs, and the behavior of the trading partners. Further analysis is necessary before drawing final conclusions

Antiphase dynamics in a multimode semiconductor laser with optical injection

A detailed experimental study of antiphase dynamics in a two-mode semiconductor laser with optical injection is presented. The device is a specially designed Fabry-Perot laser that supports two primary modes with a THz frequency spacing. Injection in one of the primary modes of the device leads to a rich variety of single and two-mode dynamical scenarios, which are reproduced with remarkable accuracy by a four dimensional rate equation model. Numerical bifurcation analysis reveals the importance of torus bifurcations in mediating transitions to antiphase dynamics and of saddle-node of limit cycle bifurcations in switching of the dynamics between single and two-mode regimes.Comment: 7 pages, 9 figure

UN/ECE Workshop on Exploring European Sulfur Abatement Strategies

This paper, prepared as a background document for the UN/ECE "Workshop on Exploring European Sulfur Abatement Strategies" (24-26 June 1991, Laxenburg, Austria), provides an analysis of the major approaches presently being explored for further reducing SO2 emissions in Europe. By using an integrated assessment model, the analysis reflects the current stake of various model developments, taking into account the most recent information on energy strategies, emission projections, atmospheric long-range transport and sensitivities of ecosystems in Europe. The paper provides quantitative results from the the "Regional Acidification Information and Simulation" (RAINS) model by analyzing various scenarios. Some more general qualitative conclusions and lessons are drawn from the model results. Further, the paper also attempts to illustrate the current limitations for scenario analysis caused by the limited availability and reliability of present data and models. The paper explores the advantages and disadvantages of alternative approaches by analyzing and evaluating different aspects of the various abatement strategies, such as relative emission reductions (compared to the baseyear 1980); cost of abatement measures; the burden to national economies as implied by emission control expenditures (i.e. the fraction of GDP required for emission reductions); the consequences on acid deposition; and their environmental impacts in terms of critical loads achievement. It should be noted however, that it is not the intention of this paper to perform any value judgments on the various strategies. Such preferences have to be established by negotiators. Undoubtedly, other considerations, which are not incorporated into this formalized analysis, will also influence the decisionmaking on the topic

Case Report of Suspected Rhabdomyolysis during Treatment with Trabectedin in a Patient with Metastatic Leiomyosarcoma

Trabectedin has been reported to occasionally induce rhabdomyolysis. In the present case, continuation of trabectedin was maintained despite suspected rhabdomyolysis related to trabectedin. Creatinine kinase levels dropped to normal levels. We suggest that continuation of trabectedin despite suspected rhabdomyolysis was safe in this specific patient

Periodic orbit theory including spin degrees of freedom

We summarize recent developments of the semiclassical description of shell effects in finite fermion systems with explicit inclusion of spin degrees of freedom, in particluar in the presence of spin-orbit interactions. We present a new approach that makes use of spin coherent states and a correspondingly enlarged classical phase space. Taking suitable limits, we can recover some of the earlier approaches. Applications to some model systems are presented.Comment: LaTeX2e, 10pp, 5 figs; contribution to 10th Nuclear Physics Workshop "Marie and Pierre Curie", 24 - 28 Sept. 2003, Kazimierz Dolny (Poland