An Optimal Algorithm for Online Multiple Knapsack

In the online multiple knapsack problem, an algorithm faces a stream of items, and each item has to be either rejected or stored irrevocably in one of n bins (knapsacks) of equal size. The gain of an algorithm is equal to the sum of sizes of accepted items and the goal is to maximize the total gain. So far, for this natural problem, the best solution was the 0.5-competitive algorithm FirstFit (the result holds for any n ? 2). We present the first algorithm that beats this ratio, achieving the competitive ratio of 1/(1+ln(2))-O(1/n) ? 0.5906 - O(1/n). Our algorithm is deterministic and optimal up to lower-order terms, as the upper bound of 1/(1+ln(2)) for randomized solutions was given previously by Cygan et al. [TOCS 2016]

Immunohistochemical assessment of mitochondrial superoxide dismutase (MnSOD) in colorectal premalignant and malignant lesions

Introduction: It is generally accepted that mitochondria are a primary source of intracellular reactive oxygen species (ROS). Under physiological circumstances they are permanently formed as by-products of aerobic metabolism in the mitochondria. To counter the harmful effect of ROS, cells possess an antioxidant defence system to detoxify ROS and avert them from accumulation at high concentrations. Mitochondria-located manganese superoxide dismutase (MnSOD, SOD2) successfully converts superoxide to the less reactive hydrogen peroxide (H2O2). To the best of our knowledge, there are no available data regarding immunohistochemical expression of MnSOD in colorectal neoplastic tissues. Aim: To investigate the immunohistochemical expression status of MnSOD in colorectal premalignant and malignant lesions. Material and methods: This study was performed on resected specimens obtained from 126 patients who had undergone surgical resection for primary sporadic colorectal cancer, and from 114 patients who had undergone colonoscopy at the Municipal Hospital in Jaworzno (Poland). Paraffin-embedded, 4-mu m-thick tissue sections were stained for rabbit polyclonal anti SOD2 antibody obtained from GeneTex (clone TF9-10-H10 from America Diagnostica). Results: Results of our study demonstrated that the development of colorectal cancer is connected with increased expression of MnSOD both in adenoma and adenocarcinoma stages. Samples of adenocarcinoma with G(2) and G(3) grade showed significantly higher levels of immunohistochemical expression of this antioxidant enzyme. Moreover, patients with the presence of lymphovascular invasion and higher degree of regional lymph node status have been also characterised by higher levels of MnSOD expression. The samples of adenoma have been characterised by higher levels of MnSOD expression in comparison to normal mucosa as well. Interestingly, there was no significant correlation between expression and histological type of adenoma. Conclusions: Development of colorectal cancer is connected with increased expression of MnSOD both in adenoma and adenocarcinoma stages. Keyword

Repolarization parameters in patients with acute ST segment elevation myocardial infarction treated with primary percutaneous coronary intervention with respect to predischarge ST-T pattern: A preliminary study

Background: Negative T wave and lack of ST segment elevation in predischarge ECG in ST-segment elevation myocardial infraction (STEMI) patients are given as markers of good prognosis. Repolarization duration, especially its late part (TpeakTend - TpTe), likewise ST-T patterns, is related to local post-myocardial infarction myocardial attributes. We analyzed the differences in QT parameters in STEMI patients with negative or not-negative T wave pattern in predischarge ECG. Methods: The data from 83 STEMI patients (LVEF > 45%, first MI, one-vessel disease) who underwent successful percutaneous coronary intervention of infarct-related coronary artery (TIMI 3 flow) were collected. According to ST-T patterns in predischarge ECG, the cohort was divided into two groups: 38 patients with persistent ST elevation and/or non-negative T wave pattern (STT+), and 45 patients with negative T wave, without ST elevation (STT-). QT, QTpeak, and TpTe intervals were obtained from 5 consecutive beats of sinus rhythm 60–70 bpm between 6 a.m. and 8 a.m. from Holter recording, corrected to the heart rate (HR) with Bazett’s formula. Results: The study groups did not differ in gender, age, or treatment. No true antiarrhythmics were given. Both QTc and TpTec were longer in STT+ patients: 459 ± 26 ms vs. 440 ± 25 ms, p = 0.01 and 108 ± 10 ms vs. 96 ± 11 ms, p = 0.000015, respectively. Prolongation of late repolarization was found both in anterior and inferior infarction. Conclusions: STEMI patients who underwent successful percutaneous coronary intervention of infarct-related coronary arteries and demonstrated persistent ST elevation, without negative T wave at hospital discharge, had a longer repolarization duration, especially the late phase of it. Further studies are necessary to assess the prognostic value of this finding

Contemporary determinants of international relatioos

Z wprowadzenia: "Nauka o stosunkach międzynarodowych nie może się obejść bez systematyzowania i porządkowania omawianej przez siebie niezwykle szerokiej materii. Poszukując odpowiedzi na pytania związane z relacjami pomiędzy uczestnikami interakcji międzynarodowych, nie sposób nie dostrzegać czynników, jakie na nie wpływają, czy to w sposób pośredni czy też bezpośredni, zależny lub niezależny od nich. Wielość tych czynników i zmienność wagi przykładanej do poszczególnych, zależnie od epoki, stwarza konieczność gruntownego badania i wskazywania na najważniejsze z nich, decydujące w danym okresie."(...