Renewable Resources, Pollution and Trade in a Small Open Economy

Industrial pollution can have damaging effects on resource-based productive sectors. International trade creates opportunities for overexploitation of the open-access renewable resources but also for separating the sectors spatially. The paper shows that, depending on the relative damage inflicted by the two industries on the environment, it is possible that the production externality will persist and that specialization in the dirty good may not be the obvious choice from a welfare perspective. Also, the resource exporter does not necessarily have to lose from trade even when specializing incompletely, due to the partially offsetting external effects.Renewable Resources, Pollution, Production Externalities, Environment, International Trade

Renewable Resources, Pollution and Trade in a Small Open Economy

Industrial pollution can have damaging effects on resource-based productive sectors. International trade creates opportunities for overexploitation of the open-access renewable resources but also for separating the sectors spatially. The paper shows that, depending on the relative damage inflicted by the two industries on the environment, it is possible that the production externality will persist and that specialization in the dirty good may not be the obvious choice from a welfare perspective. Also, the resource exporter does not necessarily have to lose from trade even when specializing incompletely, due to the partially offsetting external effects

Weakly Picard mappings

summary:In this paper we generalize the well known converse to the contraction principle due to C. Bessaga, dropping the uniqueness of the fixed point from its hypotheses. Some properties of weakly Picard mappings are given

Available online at www.tjnsa.com J. Nonlinear Sci. Appl. 6 (2013), 97–107 Research Article

schemes of fixed points for multivalued operator

Antisense-induced exon skipping for duplications in Duchenne muscular dystrophy

<p>Abstract</p> <p>Background</p> <p>Antisense-mediated exon skipping is currently one of the most promising therapeutic approaches for Duchenne muscular dystrophy (DMD). Using antisense oligonucleotides (AONs) targeting specific exons the DMD reading frame is restored and partially functional dystrophins are produced. Following proof of concept in cultured muscle cells from patients with various deletions and point mutations, we now focus on single and multiple exon duplications. These mutations are in principle ideal targets for this approach since the specific skipping of duplicated exons would generate original, full-length transcripts.</p> <p>Methods</p> <p>Cultured muscle cells from DMD patients carrying duplications were transfected with AONs targeting the duplicated exons, and the dystrophin RNA and protein were analyzed.</p> <p>Results</p> <p>For two brothers with an exon 44 duplication, skipping was, even at suboptimal transfection conditions, so efficient that both exons 44 were skipped, thus generating, once more, an out-of-frame transcript. In such cases, one may resort to multi-exon skipping to restore the reading frame, as is shown here by inducing skipping of exon 43 and both exons 44. By contrast, in cells from a patient with an exon 45 duplication we were able to induce single exon 45 skipping, which allowed restoration of wild type dystrophin. The correction of a larger duplication (involving exons 52 to 62), by combinations of AONs targeting the outer exons, appeared problematic due to inefficient skipping and mistargeting of original instead of duplicated exons.</p> <p>Conclusion</p> <p>The correction of DMD duplications by exon skipping depends on the specific exons targeted. Its options vary from the ideal one, restoring for the first time the true, wild type dystrophin, to requiring more 'classical' skipping strategies, while the correction of multi-exon deletions may need the design of tailored approaches.</p

Iterates of a class of discrete linear operators via contraction principle

summary:In this paper we are concerned with a general class of positive linear operators of discrete type. Based on the results of the weakly Picard operators theory our aim is to study the convergence of the iterates of the defined operators and some approximation properties of our class as well. Some special cases in connection with binomial type operators are also revealed

Use of shear waves for diagnosis and ablation monitoring of prostate cancer: a feasibility study

Prostate cancer remains as a major healthcare issue. Limitations in current diagnosis and treatment monitoring techniques imply that there is still a need for improvements. The efficacy of prostate cancer diagnosis is still low, generating under and over diagnoses. High intensity focused ultrasound ablation is an emerging treatment modality, which enables the noninvasive ablation of pathogenic tissue. Clinical trials are being carried out to evaluate its longterm efficacy as a focal treatment for prostate cancer. Successful treatment of prostate cancer using non-invasive modalities is critically dependent on accurate diagnostic means and is greatly benefited by a real-time monitoring system. While magnetic resonance imaging remains the gold standard for prostate imaging, its wider implementation for prostate cancer diagnosis remains prohibitively expensive. Conventional ultrasound is currently limited to guiding biopsy. Elastography techniques are emerging as a promising real-time imaging method, as cancer nodules are usually stiffer than adjacent healthy prostatic tissue. In this paper, a new transurethral approach is proposed, using shear waves for diagnosis and ablation monitoring of prostate cancer. A finite-difference time domain model is developed for studying the feasibility of the method, and an inverse problem technique based on genetic algorithms is proposed for reconstructing the location, size and stiffness parameters of the tumour. Preliminary results indicate that the use of shear waves for diagnosis and monitoring ablation of prostate cancer is feasible

Fabrication and characterization of polyurethane foam prepared from liquefied oil palm mesocarp fibre with renewable monomer made from waste cooking oil

This study aims performance characteristics of polyurethane foams prepared by the reaction of biopolyol prepared from liquefied oil palm mesocarp fibre and renewable monomer with methylene diphenyl diisocyanate. The effect of prepared oil palm mesocarp biopolyol with incorporation of renewable monomer of PU foam on the thermal stability, mechanical properties and was analyzed by thermo gravimetric analysis, tensile and compressive tests and Fourier transform infrared spectroscopy. The improved thermal properties were achieved at a composition of oil palm mesocarp fibre foams (PMF). Oil PMF foams showed mechanical strength as compared to renewable monomer foams. PU foam prepared from oil palm mesocarp biopolyol with incorporation of renewable monomer improved the foams strength. An infrared spectroscopy study demonstrated the formation of urethane linkage

Wave propagation in a fractional viscoelastic tissue model: Application to transluminal procedures

In this article, a wave propagation model is presented as the first step in the development of a new type of transluminal procedure for performing elastography. Elastography is a medical imaging modality for mapping the elastic properties of soft tissue. The wave propagation model is based on a Kelvin Voigt Fractional Derivative (KVFD) viscoelastic wave equation, and is numerically solved using a Finite Difference Time Domain (FDTD) method. Fractional rheological models, such as the KVFD, are particularly well suited to model the viscoelastic response of soft tissue in elastography. The transluminal procedure is based on the transmission and detection of shear waves through the luminal wall. Shear waves travelling through the tissue are perturbed after encountering areas of altered elasticity. These perturbations carry information of medical interest that can be extracted by solving the inverse problem. Scattering from prostate tumours is used as an example application to test the model. In silico results demonstrate that shear waves are satisfactorily transmitted through the luminal wall and that echoes, coming from reflected energy at the edges of an area of altered elasticity, which are feasibly detectable by using the transluminal approach. The model here presented provides a useful tool to establish the feasibility of transluminal procedures based on wave propagation and its interaction with the mechanical properties of the tissue outside the lumen