User responses to CPA reports on forecasts; Technical Research Report 2

https://egrove.olemiss.edu/aicpa_news/1272/thumbnail.jp

Venous thromboembolism following colorectal resection

Aim The study investigated the rate of significant venous thromboembolism (VTE) following colorectal resection during the index admission and over 1 year following discharge. It identifies risk factors associated with VTE and considers the length of VTE prophylaxis required. Method All adult patients who underwent colorectal resections in England between April 2007 and March 2008 were identified using Hospital Episode Statistics data. They were studied during the index admission and followed for a year to identify any patients who were readmitted as an emergency with a diagnosis of deep venous thrombosis or pulmonary embolism. Results In all, 35 997 patients underwent colorectal resection during the period of study. The VTE rate was 2.3%. Two hundred and one (0.56%) patients developed VTE during the index admission and 571 (1.72%) were readmitted with VTE. Following discharge from the index admission, the risk of VTE in patients with cancer remained elevated for 6 months compared with 2 months in patients with benign disease. Age, postoperative stay, cancer, emergency admission and emergency surgery for patients with inflammatory bowel disease (IBD) were all independent risk factors associated with an increased risk of VTE. Patients with ischaemic heart disease and those having elective minimal access surgery appear to have lower levels of VTE. Conclusion This study adds to the benefits of minimal access surgery and demonstrates an additional risk to patients undergoing emergency surgery for IBD. The majority of VTE cases occur following discharge from the index admission. Therefore, surgery for cancer, emergency surgery for IBD and those with an extended hospital stay may benefit from extended VTE prophylaxis. This study demonstrates that a stratified approach may be required to reduce the incidence of VTE

Quadruplewild-type (WT) GIST: defining the subset of GIST that lacks abnormalities of KIT, PDGFRA, SDH, or RAS signaling pathways

A subset of GISTs lack mutations in the KIT/PDGFRA or RAS pathways and yet retain an intact succinate dehydrogensase (SDH) complex. We propose that these KIT/PDGFRA/SDH/RAS-P WT GIST tumors be designated as quadruple wild-type (WT) GIST. Further molecular and clinicophatological characterization of quadruple WT GIST will help to determine their prognosis as well as assist in the optimization of medical management, including clinical test of novel therapies

On the infrared freezing of perturbative QCD in the Minkowskian region

The infrared freezing of observables is known to hold at fixed orders of perturbative QCD if the Minkowskian quantities are defined through the analytic continuation from the Euclidean region. In a recent paper [1] it is claimed that infrared freezing can be proved also for Borel resummed all-orders quantities in perturbative QCD. In the present paper we obtain the Minkowskian quantities by the analytic continuation of the all-orders Euclidean amplitudes expressed in terms of the inverse Mellin transform of the corresponding Borel functions [2]. Our result shows that if the principle of analytic continuation is preserved in Borel-type resummations, the Minkowskian quantities exhibit a divergent increase in the infrared regime, which contradicts the claim made in [1]. We discuss the arguments given in [1] and show that the special redefinition of Borel summation at low energies adopted there does not reproduce the lowest order result obtained by analytic continuation.Comment: 19 pages, 1 figur

Optimal solutions to matrix-valued Nehari problems and related limit theorems

In a 1990 paper Helton and Young showed that under certain conditions the optimal solution of the Nehari problem corresponding to a finite rank Hankel operator with scalar entries can be efficiently approximated by certain functions defined in terms of finite dimensional restrictions of the Hankel operator. In this paper it is shown that these approximants appear as optimal solutions to restricted Nehari problems. The latter problems can be solved using relaxed commutant lifting theory. This observation is used to extent the Helton and Young approximation result to a matrix-valued setting. As in the Helton and Young paper the rate of convergence depends on the choice of the initial space in the approximation scheme.Comment: 22 page

Methods for Partitioning Data to Improve Parallel Execution Time for Sorting on Heterogeneous Clusters

International audienceThe aim of the paper is to introduce general techniques in order to optimize the parallel execution time of sorting on a distributed architectures with processors of various speeds. Such an application requires a partitioning step. For uniformly related processors (processors speeds are related by a constant factor), we develop a constant time technique for mastering processor load and execution time in an heterogeneous environment and also a technique to deal with unknown cost functions. For non uniformly related processors, we use a technique based on dynamic programming. Most of the time, the solutions are in O(p) (p is the number of processors), independent of the problem size n. Consequently, there is a small overhead regarding the problem we deal with but it is inherently limited by the knowing of time complexity of the portion of code following the partitioning