262,511 research outputs found
A Survey of the Literature on the WTO Dispute Settlement System
No full textThis paper surveys the law and economics literature on WTO dispute settlement. As a background, we first briefly lay out main features of the legal framework, and discuss possible roles of a dispute settlement mechanism. We then discuss the two main themes in the empirical literature on dispute settlement: (i) the determinants of participation by members as complainants, respondents and third parties; and (ii) the role of the DS system for the settling of disputes. The paper finally points to a number of areas that are in need of further research.WTO; Dispute Settlement; DSU
Use of radiobiological modeling in treatment plan evaluation and optimization of prostate cancer radiotherapy
No full textThere are many tools available that are used to evaluate a radiotherapy treatment plan, such as isodose distribution charts, dose volume histograms (DVH), maximum, minimum and mean doses of the dose distributions as well as DVH point dose constraints. All the already mentioned evaluation tools are dosimetric only without taking into account the radiobiological characteristics of tumors or OARs. It has been demonstrated that although competing treatment plans might have similar mean, maximum or minimum doses they may have significantly different clinical outcomes (Mavroidis et al. 2001). For performing a more complete treatment plan evaluation and comparison the complication-free tumor control probability (P+) and the biologically effective uniform dose (D ) have been proposed (Källman et al. 1992a, Mavroidis et al. 2000). The D concept denotes that any two dose distributions within a target or OAR are equivalent if they produce the same probability for tumor control or normal tissue complication, respectively (Mavroidis et al. 2001)..
Beyond the WTO? An anatomy of EU and US preferential trade agreements. Bruegel Blueprint Series 7, February 2009
No full textThere is a growing concern that Preferential Trading Agreements (PTAs) go far beyond the scope of current WTO agreements, maybe creating unfair trade relations. This Blueprint looks in detail at all the provisions of all the PTAs signed by the EC or the US and other WTO members. Henrik Horn, Petros C. Mavroidis and André Sapri find that Europe and the US have adopted very different approaches to PTAs; however, both powers may also be seeking to protect their global regulatory priorities
Determination and use of radiobiological response parameters in radiation therapy optimization
No full textOptimization of radiation therapy is critically dependent on the use of patient related information. For this reason, radiobiological models describing the dependence of tumour and normal tissue responses on the irradiated volume and the dose-time-fractionation schedule should be introduced. In addition, the heterogeneity of the delivered dose distribution and tumour or normal tissue sensitivity variations have to be taken into account clinically. In the present study, a treatment optimization procedure is used that considers the shape and the structure of the target tissues and healthy organs at risk, their relative position and their dose-response relations for the individual patient.Mathematical models largely based on the Poisson statistics and the linear-quadratic model of cell kill, have been used to quantify the radiobiological response of normal human tissues and tumours to radiation therapy. The presented models predict a decreasing probability of achieving complication free tumour control with increasing tumour size and increasing volume of normal tissues irradiated. The radiobiological parameters D50, gamma, sigma and Vref of the Poisson and relative seriality models have been estimated for certain normal tissues and targets. The process for determining these dose-response relations was based on clinical materials where the treatment information and follow-up results of the individual patient were available. The statistical methods used, estimated and verified the parameters and their uncertainties. The clinical range of variability of the dose-response relations is important for their correct use in the clinical routine.The clinical use of the derived dose-response relations is demonstrated using radiobiological parameters for different tumours and normal tissues that were also calculated based on data clinical trials. A biological evaluation procedure is introduced and applied on clinical cases. This procedure uses the biological models and dose-response data of the involved organs and optimizes the dose level of the treatment technique under study. This is done by evaluating the plan using the P+, objective, which estimates the probability to achieve tumour cure without having severe complications to the healthy tissues. The clinical value of biologically based treatment planning was compared with alternative physical criteria (e.g. tolerance doses) and with the judgment of personnel on particular clinical cases.It is demonstrated that the radiobiological objective functions allow a much higher conformity and a more clinically relevant scoring of the treatment outcome. The probability of achieving tumour control without fatal complications in normal tissues is increased and the dose delivery optimized. Recent developments can reduce or even eliminate the need for intracavitary treatment by delivering more conformal dose distributions using intensity modulated external dose delivery. In these cases the reliability of the patient setup becomes critical for the effectiveness of the treatment. It is realized that accurate information concerning the response of different organs to fractionated intensity modulated radiation therapy is the key to true optimization of the delivered dose distribution.List of scientific papersI. Mavroidis P, Laurell G, Kraepelien T, Fernberg JO, Lind BK, Brahme A (2001). "Dose response parameters for esophageal stricture from head & neck radiotherapy." Int J Radiat Oncol Biol Phys (Submitted)II. Mavroidis P, Theodorou K, Lefkopoulos D, Nataf F, Karlsson B, Lax I, Kappas C, Lind BK, Brahme A (2001). "Prediction of AVM obliteration after stereotactic radiotherapy using radiobiological modelling." Radiother Oncol (Submitted)III. Mavroidis P, Axelsson S, Hyodynmaa S, Rajala MA, Lind BK, Brahme A (2001). "Positioning uncertainty and breathing effects on dose delivery and radiation pneumonitis prediction in breast cancer." Acta Oncol (Submitted)IV. Mavroidis P, Kappas C, Lind BK (1997). "A computer program for evaluating the probability of complication-free tumor control incorporated in a commercial treatment planning system." J Balcan Union Oncol 3: 257-64V. Lind BK, Mavroidis P, Hyodynmaa S, Kappas C (1999). "Optimization of the dose level for a given treatment plan to maximize the complication-free tumor cure" Acta Oncol 38(6): 787-98 https://pubmed.ncbi.nlm.nih.gov/10522770VI. Mavroidis P, Lind BK, Van Dijk J, Koedooder K, De Neve W, De Wagter C, Planskoy B, Rosenwald JC, Proimos B, Kappas C, Claudia D, Benassi M, Chierego G, Brahme A. (2000). "Comparison of conformal radiation therapy techniques within the dynamic radiotherapy project Dynarad. " Phys Med Biol 45(9): 2459-81 https://pubmed.ncbi.nlm.nih.gov/11008949VII. Mavroidis P, Lind BK, Brahme A (2001). "Biologically effective uniform dose (D) for specification, report and comparison of dose response relations and treatment plans. " Phys Med Biol 46(10): 2607-30 https://pubmed.ncbi.nlm.nih.gov/11686278</p
FASTCUDA: Open Source FPGA Accelerator &amp; Hardware-Software Codesign Toolset for CUDA Kernels
No full textUsing FPGAs as hardware accelerators that communicate with a central CPU is becoming a common practice in the embedded design world but there is no standard methodology and toolset to facilitate this path yet. On the other hand, languages such as CUDA and OpenCL provide standard development environments for Graphical Processing Unit (GPU) programming. FASTCUDA is a platform that provides the necessary software toolset, hardware architecture, and design methodology to efficiently adapt the CUDA approach into a new FPGA design flow. With FASTCUDA, the CUDA kernels of a CUDA-based application are partitioned into two groups with minimal user intervention: those that are compiled and executed in parallel software, and those that are synthesized and implemented in hardware. A modern low power FPGA can provide the processing power (via numerous embedded micro-CPUs) and the logic capacity for both the software and hardware implementations of the CUDA kernels. This paper describes the system requirements and the architectural decisions behind the FASTCUDA approach
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
MODELLING OF ATMOSPHERIC FLOW AND DISPERSION IN THE WAKE OF A CYLINDRICAL OBSTACLE
No full textThis paper presents computational simulations of atmospheric dispersion experiments conducted around isolated
obstacles in the field. The computational tool used for the simulations was the code ADREA-HF, which was especially developed
for the simulation of the dispersion of positively or negatively buoyant gases in complicated geometries. The field experiments
simulated involve a single cylindrical obstacle normal to the mean wind direction and two upwind sources of ammonia and propane,
with the ammonia source located at different lateral positions (Mavroidis et al., 2003). Concentrations and concentration fluctuations
for both gases were calculated by the model and compared with the experimental results to evaluate the model performance.
Specific characteristics of dispersion were investigated using the computational tool. Comparisons of experimental and model
results with the case of dispersion around an isolated cubical obstacle are also presented and discussed
Protecting Animals 36: Author Witi Ihimaera
No full textIn this very special episode of Knowing Animals I am joined by beloved New Zealand author Witi Ihimaera. Witi has written many books featuring nonhuman animals. He offers us a non-colonial lens through which to think about the human/nonhuman relationship
- …
