33 research outputs found

    Decomposition of bipartite graphs under degree constraints

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    Let G = (A, B; E) be a bipartite graph. Let e1, e2 be nonnegative integers, and f1, f2 nonnegative integer-valued functions on V(G) such that ei ≤|E|≤ e1 + e2 and fi(v)≤d(v)≤f1(v) + f2(v) for all v ε V(G) (i = 1, 2). Necessary and sufficient conditions are obtained for G to admit a decomposition in spanning subgraphs G1 = (A, B; E1) and G2 = (A, B; E2) such that |Ei|≤ei and dGi(v)≤fi(v) for all v ε V(G) (i = 1, 2). The result generalizes a known characterization of bipartite graphs with a k-factor. Its proof uses flow theory and is a refinement of the proof of an analogous result due to Folkman and Fulkerson. By applying corresponding flow algorithms, the described decomposition can be found in polynomial time if it exists. As an application, an assignment problem is solved

    Forbidden subgraphs that imply Hamiltonian-connectedness

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    It is proven that if GG is a 33-connected claw-free graph which is also Z3Z_3-free (where Z3Z_3 is a triangle with a path of length 33 attached), P6P_6-free (where P6P_6 is a path with 66 vertices) or H1H_1-free (where H1H_1 consists of two disjoint triangles connected by an edge), then GG is Hamiltonian-connected. Also, examples will be described that determine a finite family of graphs L\cal{L} such that if a 3-connected graph being claw-free and LL-free implies GG is Hamiltonian-connected, then L∈LL\in\cal{L}. \u

    Incident gallstones during somatostatin analog treatment are associated with acute biliary complications especially after discontinuation

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    Introduction Gallstones are a known adverse effect of somatostatin analogs, but the exact incidence and clinical implications are unknown.Objectives The aim of this study was to investigate the incidence of gallstones on imaging and related complications in unbiased trial data.Methods Data from the DIPAK 1 trial, in which 305 polycystic kidney disease patients were randomized to standard of care (SoC) or lanreotide for 120 weeks, were used. Magnetic resonance imaging (MRI) was performed at baseline and end of treatment and was assessed for the presence, number, and size of gallstones. For all patients who had gallstones at the end of the trial, we obtained follow-up after the trial.Results Of 249 patients with data available, 11 patients randomized to lanreotide and four randomized to SoC had gallstones at baseline. During the study, new gallstones were formed in 19/124 patients using lanreotide (15%) and 1/125 patients receiving SoC (1%). The odds ratio for gallstone formation with lanreotide use was 25.9 (95% confidence interval 3.37-198.8; p 20 stones in 69% of patients) and small (<= 3 mm in 63% of patients). Of the 19 patients with incident gallstones during lanreotide treatment, 9 experienced gallstone-associated complications, 8 of whom experienced gallstone-associated complications after discontinuation of treatment (median time after discontinuation 2.5 years). In patients with gallstones at baseline and in patients receiving SoC, no complications occurred.Conclusions Treatment with a somatostatin analog leads to the formation of multiple, small gallstones that are associated with severe complications, especially after discontinuation of therapy.Functional Genomics of Systemic Disorder

    Screening for distant metastases in patients with ipsilateral breast tumor recurrence: the impact of different imaging modalities on distant recurrence-free interval

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    Purpose In patients with ipsilateral breast tumor recurrence (IBTR), the detection of distant disease determines whether the intention of the treatment is curative or palliative. Therefore, adequate preoperative staging is imperative for optimal treatment planning. The aim of this study is to evaluate the impact of conventional imaging techniques, including chest X-ray and/or CT thorax-(abdomen), liver ultrasonography(US), and skeletal scintigraphy, on the distant recurrence-free interval (DRFI) in patients with IBTR, and to compare conventional imaging with 18F-FDG PET-CT or no imaging at all. Methods This study was exclusively based on the information available at time of diagnoses of IBTR. To adjust for differences in baseline characteristics between the three imaging groups, a propensity score (PS) weighted method was used. Results Of the 495 patients included in the study, 229 (46.3%) were staged with conventional imaging, 89 patients (19.8%) were staged with 18F-FDG PET-CT, and in 168 of the patients (33.9%) no imaging was used (N=168). After a follow-up of approximately 5 years, 14.5% of all patients developed a distant recurrence as frst event after IBTR. After adjusting for the PS weights, the Cox regression analyses showed that the diferent staging methods had no signifcant impact on the DRFI. Conclusions This study showed a wide variation in the use of imaging modalities for staging IBTR patients in the Netherlands. After using PS weighting, no statistically signifcant impact of the diferent imaging modalities on DRFI was shown. Based on these results, it is not possible to recommend staging for distant metastases using 18F-FDG PET-CT over conventional imaging technique

    The Involvement of Sphingolipids in Multidrug Resistance

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    Test for potential protective effects of Catosal on mortality of fish due to temporary hypoxia

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    Studies with several fish species have shown that fishes during transport are exposed to different stressful stimuli that may cause adverse physiological reactions, which may lead to mortality. Given the fact that ornamental fish represent a high economical value, reduction of stress in ornamental fish during transport to minimise mortality is essential

    Electrical stunning by decapitation or chilling of African catfish (Clarias gariepinus): assessment of behavioural and neural parameters and product quality

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    The objective of this study was to assess neural and behavioural responses in farmed African catfish (Clarias gariepinus) upon electrical stunning in combination with decapitation or chilling. To assess the possibility of scaling up one or both experimental methods, two trials were performed in an experimental setting. The product quality of the collected samples was compared with the currently applied industrial method: live chilling. After electrical stunning in combination with decapitation, the fish showed spikes alternated with theta and delta waves on the EEG, followed by minimal brain activity after 20±10 s. The same traces on the EEGs were observed after electrical stunning in combination with chilling. Here, minimal brain activity occurred after 22±11 s. Within a confidence level of 95%, the percentage of African catfish that was effectively stunned after administration of an electrical current of 1.5 A dm2, 300 V (50 Hz a.c.), followed by decapitation or chilling was above 91%. The analysis yield and evolution of liquid loss showed significant (
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