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Motivated by problems in comparative genomics and paleogenomics, we study the computational complexity of the Gapped Consecutive-Ones Property ((k,δ)-C1P) Problem: given a binary matrix M and two integers k and δ, decide if the columns of M can be permuted such that each row contains at most k blocks of ones and no two neighboring blocks of ones are separated by a gap of more than δ zeros. The classical C1P decision problem, which is known to be polynomial-time solvable is equivalent to the (1,0)-C1P problem. We extend our earlier results on this problem [C. Chauve, J. Mauch, M. Patterson, On the gapped consecutive-ones property, in: Proceedings of the European Conference on Combinatorics, Graphs Theory and Applications (EuroComb), in: Electronic Notes in Discrete Mathematics, vol. 34, 2009, pp. 121-125] to show that for every k

Background Origin of electrocardiographic (ECG) alterations during intravascular injection of local anaesthetic solutions is controversial. The aim of this study was to elucidate whether epinephrine, bupivacaine or their combination is responsible for ECG alteration. Methods Forty-five piglets were randomized into three groups. After induction of general anaesthesia using sevoflurane and peripheral venous cannulation, the trachea was intubated, the lungs were artificially ventilated, and anaesthesia was maintained by sevoflurane. Under steady state 0.2 ml kg −1 and after 10 min 0.4 ml kg −1 of one of the following three test solutions was administered i.v.: bupivacaine 0.125% (Group 1), bupivacaine 0.125%+epinephrine 1:200 000 (Group 2), and plain epinephrine 1:200 000 (Group 3). The ECG was analysed for alterations in heart rate and T-elevation. Results After injection of 0.2 or 0.4 ml kg −1 test solution, an increase in heart rate of at least 10% was found in none of Group 1 and in all of Groups 2 and 3. After application of 0.2 ml kg −1 test solution, T-elevation was found in 7% of Group 1 and in 93% of Groups 2 and 3. The injection of 0.4 ml kg −1 revealed a T-elevation in 27%, 100%, and 100%, respectively, in Groups 1, 2, and 3. Conclusions This animal model demonstrated that increases in heart rate and T-elevation in the ECG during i.v. application of a common test dose (0.2 ml kg −1 ) of bupivacaine are caused by epinephrine addition. Whether higher doses of bupivacaine alone can cause similar ECG changes or not requires further studies.