Kernelization and Sparseness: the case of Dominating Set

We prove that for every positive integer $r$ and for every graph class $\mathcal G$ of bounded expansion, the $r$-Dominating Set problem admits a linear kernel on graphs from $\mathcal G$. Moreover, when $\mathcal G$ is only assumed to be nowhere dense, then we give an almost linear kernel on $\mathcal G$ for the classic Dominating Set problem, i.e., for the case $r=1$. These results generalize a line of previous research on finding linear kernels for Dominating Set and $r$-Dominating Set. However, the approach taken in this work, which is based on the theory of sparse graphs, is radically different and conceptually much simpler than the previous approaches. We complement our findings by showing that for the closely related Connected Dominating Set problem, the existence of such kernelization algorithms is unlikely, even though the problem is known to admit a linear kernel on $H$-topological-minor-free graphs. Also, we prove that for any somewhere dense class $\mathcal G$, there is some $r$ for which $r$-Dominating Set is W[$2$]-hard on $\mathcal G$. Thus, our results fall short of proving a sharp dichotomy for the parameterized complexity of $r$-Dominating Set on subgraph-monotone graph classes: we conjecture that the border of tractability lies exactly between nowhere dense and somewhere dense graph classes.Comment: v2: new author, added results for r-Dominating Sets in bounded expansion graph

Prognostic value of circulating tumor cells and disseminated tumor cells in patients with ovarian cancer: a systematic review and meta-analysis

Recent studies have shown diagnostic and prognostic values of circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) in various cancers, including ovarian cancer. We aimed to evaluate the association of CTCs and/or DTCs with the clinical outcomes of ovarian cancer. Clinical studies of CTCs/DTCs of ovarian cancer were included for systematic review and meta-analysis. A total of 236 studies were screened but only 16 qualified studies with 1623 subjects were included. Odds ratio (OR) showed CTCs/DTCs were not significantly associated with serous carcinoma (OR = 0.71 [0.49, 1.05]), lymph node metastasis (OR 1.14 [0.67, 1.93]), and residual disease (OR 1.45 [0.90, 2.34]); but significantly associated with advanced tumor staging (OR = 1.90 [1.02, 3.56]). The overall pooled hazard ratio (HR) of CTCs/DTCs on OS and PFS/DFS was 1.94 [1.56– 2.40] and 1.99 [1.59–2.50], respectively. Subgroup analyses revealed that CTCs were significantly associated OS (HR 1.97 [1.50-2.58]) and PFS/DFS (HR 2.52 [1.83-3.48]), while DTCs was significantly associated OS (HR 1.89 [1.33, 2.68]) and PFS/DFS (HR 1.60 [1.17, 2.19]). Meta-analysis showed strong relationship of CTCs/DTCs with advanced staging, treatment response and poor prognosis in patients with ovarian cancer. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13048-015-0168-9) contains supplementary material, which is available to authorized users

: Congrès Brésilien sur les Sciences Humaines et Sociales et la Santé.

Seropositivity e envelhecimento na França, na Espanha e em Portugal. Congrès Brésilien sur les Sciences Humaines et Sociales et la Santé. Rio de Janeiro 2012 Conférence invitée au IV Congrès international en promotion à la santé : promotion de la santé - avancements et défis, organisé par l'Université de Fortaleza, l'Université de l'Etat du Ceara et Université Fédérale du Ceara. Université de Fortaleza (Fortaleza, Ceara, Brésil)(présentée par Mendes-Leite, R.

: Congrès Brésilien sur les Sciences Humaines et Sociales et la Santé.

Seropositivity e envelhecimento na França, na Espanha e em Portugal. Congrès Brésilien sur les Sciences Humaines et Sociales et la Santé. Rio de Janeiro 2012 Conférence invitée au IV Congrès international en promotion à la santé : promotion de la santé - avancements et défis, organisé par l'Université de Fortaleza, l'Université de l'Etat du Ceara et Université Fédérale du Ceara. Université de Fortaleza (Fortaleza, Ceara, Brésil)(présentée par Mendes-Leite, R.