1,115 research outputs found
On Feedback Vertex Set: New Measure and New Structures
We present a new parameterized algorithm for the {feedback vertex set}
problem ({\sc fvs}) on undirected graphs. We approach the problem by
considering a variation of it, the {disjoint feedback vertex set} problem ({\sc
disjoint-fvs}), which finds a feedback vertex set of size that has no
overlap with a given feedback vertex set of the graph . We develop an
improved kernelization algorithm for {\sc disjoint-fvs} and show that {\sc
disjoint-fvs} can be solved in polynomial time when all vertices in have degrees upper bounded by three. We then propose a new
branch-and-search process on {\sc disjoint-fvs}, and introduce a new
branch-and-search measure. The process effectively reduces a given graph to a
graph on which {\sc disjoint-fvs} becomes polynomial-time solvable, and the new
measure more accurately evaluates the efficiency of the process. These
algorithmic and combinatorial studies enable us to develop an
-time parameterized algorithm for the general {\sc fvs} problem,
improving all previous algorithms for the problem.Comment: Final version, to appear in Algorithmic
National priorities for perioperative research in South Africa
Background. Perioperative research is currently unco-ordinated in South Africa (SA), with no clear research agenda.Objective. To determine the top ten national research priorities for perioperative research in SA.Methods. A Delphi technique was used to establish consensus on the top ten research priorities.Results. The top ten research priorities were as follows: (i) establishment of a national database of (a) critical care outcomes, and (b) critical care resources; (ii) a randomised controlled trial of preoperative B-type natriuretic peptide-guided medical therapy to decrease major adverse cardiac events following non-cardiac surgery; (iii) a national prospective observational study of the outcomes associated with paediatric surgical cases; (iv) a national observational study of maternal and fetal outcomes following operative delivery in SA; (v) a steppedwedge trial of an enhanced recovery after surgery programme for (a) surgery, (b) obstetrics, (c) emergency surgery, and (d) trauma surgery; (vi) a stepped-wedge trial of a surgical safety checklist on patient outcomes in SA; (vii) a prospective observational study of perioperative outcomes after surgery in district general hospitals in SA; (viii) short-course interventions to improve anaesthetic skills in rural doctors; (ix) studies of the efficacy of simulation training to improve (a) patient outcomes, (b) team dynamics, and (c) leadership; and (x) development and validation of a risk stratification tool for SA surgery based on the South African Surgical Outcomes Study (SASOS) data.Conclusions. These research priorities provide the structure for an intermediate term research agenda
Liver transplantation for type I and type IV glycogen storage disease
Progressive liver failure or hepatic complications of the primary disease led to orthotopic liver transplantation in eight children with glycogen storage disease over a 9-year period. One patient had glycogen storage disease (GSD) type I (von Gierke disease) and seven patients had type IV GSD (Andersen disease). As previously reported [19], a 16.5-year-old-girl with GSD type I was successfully treated in 1982 by orthotopic liver transplantation under cyclosporine and steroid immunosuppression. The metabolic consequences of the disease have been eliminated, the renal function and size have remained normal, and the patient has lived a normal young adult life. A late portal venous thrombosis was treated successfully with a distal splenorenal shunt. Orthotopic liver transplantation was performed in seven children with type N GSD who had progressive hepatic failure. Two patients died early from technical complications. The other five have no evidence of recurrent hepatic amylopectinosis after 1.1–5.8 postoperative years. They have had good physical and intellectual maturation. Amylopectin was found in many extrahepatic tissues prior to surgery, but cardiopathy and skeletal myopathy have not developed after transplantation. Postoperative heart biopsies from patients showed either minimal amylopectin deposits as long as 4.5 years following transplantation or a dramatic reduction in sequential biopsies from one patient who initially had dense myocardial deposits. Serious hepatic derangement is seen most commonly in types T and IV GSD. Liver transplantation cures the hepatic manifestations of both types. The extrahepatic deposition of abnormal glycogen appears not to be problematic in type I disease, and while potentially more threatening in type IV disease, may actually exhibit signs of regression after hepatic allografting
Effect of diindolylmethane supplementation on low-grade cervical cytological abnormalities: double-blind, randomised, controlled trial
This work was supported by a Cancer Research UK project grant (C8162/A4609 project costs) and a programme grant
(C8162/A10406)
Impacts of organic and conventional crop management on diversity and activity of free-living nitrogen fixing bacteria and total bacteria are subsidiary to temporal effects
A three year field study (2007-2009) of the diversity and numbers of the total and metabolically active free-living diazotophic bacteria and total bacterial communities in organic and conventionally managed agricultural soil was conducted at the Nafferton Factorial Systems Comparison (NFSC) study, in northeast England. The result demonstrated that there was no consistent effect of either organic or conventional soil management across the three years on the diversity or quantity of either diazotrophic or total bacterial communities. However, ordination analyses carried out on data from each individual year showed that factors associated with the different fertility management measures including availability of nitrogen species, organic carbon and pH, did exert significant effects on the structure of both diazotrophic and total bacterial communities. It appeared that the dominant drivers of qualitative and quantitative changes in both communities were annual and seasonal effects. Moreover, regression analyses showed activity of both communities was significantly affected by soil temperature and climatic conditions. The diazotrophic community showed no significant change in diversity across the three years, however, the total bacterial community significantly increased in diversity year on year. Diversity was always greatest during March for both diazotrophic and total bacterial communities. Quantitative analyses using qPCR of each community indicated that metabolically active diazotrophs were highest in year 1 but the population significantly declined in year 2 before recovering somewhat in the final year. The total bacterial population in contrast increased significantly each year. Seasonal effects were less consistent in this quantitative study
The Cyprinodon variegatus genome reveals gene expression changes underlying differences in skull morphology among closely related species
Genes in durophage intersection set at 15 dpf. This is a comma separated table of the genes in the 15 dpf durophage intersection set. Given are edgeR results for each pairwise comparison. Columns indicating whether a gene is included in the intersection set at a threshold of 1.5 or 2 fold are provided. (CSV 13Â kb
Saffold virus is able to productively infect primate and rodent cell lines and induces apoptosis in these cells
10.1038/emi.2014.15Emerging Microbes and Infections3
- …