5 research outputs found
Parameterized Edge Hamiltonicity
We study the parameterized complexity of the classical Edge Hamiltonian Path
problem and give several fixed-parameter tractability results. First, we settle
an open question of Demaine et al. by showing that Edge Hamiltonian Path is FPT
parameterized by vertex cover, and that it also admits a cubic kernel. We then
show fixed-parameter tractability even for a generalization of the problem to
arbitrary hypergraphs, parameterized by the size of a (supplied) hitting set.
We also consider the problem parameterized by treewidth or clique-width.
Surprisingly, we show that the problem is FPT for both of these standard
parameters, in contrast to its vertex version, which is W-hard for
clique-width. Our technique, which may be of independent interest, relies on a
structural characterization of clique-width in terms of treewidth and complete
bipartite subgraphs due to Gurski and Wanke
EAES recommendations for the management of gastroesophageal reflux disease
BACKGROUND:
Gastroesophageal reflux disease (GERD) is one of the most frequent benign disorders of the upper gastrointestinal tract. Management of GERD has always been controversial since modern medical therapy is very effective, but laparoscopic fundoplication is one of the few procedures that were quickly adapted to the minimal access technique. The purpose of this project was to analyze the current knowledge on GERD in regard to its pathophysiology, diagnostic assessment, medical therapy, and surgical therapy, and special circumstances such as GERD in children, Barrett's esophagus, and enteroesophageal and duodenogastroesophageal reflux.
METHODS:
The European Association of Endoscopic Surgery (EAES) has tasked a group of experts, based on their clinical and scientific expertise in the field of GERD, to establish current guidelines in a consensus development conference. The expert panel was constituted in May 2012 and met in September 2012 and January 2013, followed by a Delphi process. Critical appraisal of the literature was accomplished. All articles were reviewed and classified according to the hierarchy of level of evidence and summarized in statements and recommendations, which were presented to the scientific community during the EAES yearly conference in a plenary session in Vienna 2013. A second Delphi process followed discussion in the plenary session.
RESULTS:
Recommendations for pathophysiologic and epidemiologic considerations, symptom evaluation, diagnostic workup, medical therapy, and surgical therapy are presented. Diagnostic evaluation and adequate selection of patients are the most important features for success of the current management of GERD. Laparoscopic fundoplication is the most important therapeutic technique for the success of surgical therapy of GERD.
CONCLUSIONS:
Since the background of GERD is multifactorial, the management of this disease requires a complex approach in diagnostic workup as well as for medical and surgical treatment. Laparoscopic fundoplication in well-selected patients is a successful therapeutic option