Approximate Submodularity and Its Implications in Discrete Optimization

Submodularity, a discrete analog of convexity, is a key property in discrete optimization that features in the construction of valid inequalities and analysis of the greedy algorithm. In this paper, we broaden the approximate submodularity literature, which so far has largely focused on variants of greedy algorithms and iterative approaches. We define metrics that quantify approximate submodularity and use these metrics to derive properties about approximate submodularity preservation and extensions of set functions. We show that previous analyses of mixed-integer sets, such as the submodular knapsack polytope, can be extended to the approximate submodularity setting. In addition, we demonstrate that greedy algorithm bounds based on our notions of approximate submodularity are competitive with those in the literature, which we illustrate using a generalization of the uncapacitated facility location problem

Toxicological evaluation of Moringa oleifera Lam seeds and leaves in Wistar rats

Miracle tree (Moringa oleifera) as it is popularly called, has been found useful both medicinally and economically. Its consumption both in the raw and as processed preparations has increased a great deal thus making the fast growing plant a highly valued and cultivated one in the tropics and sub-tropics. There is however, little reference to its toxicity profile and evaluation. Hence, this study evaluated the toxicity profiles of the leaves and seeds of M. oleifera and the corresponding effects on vital organs of Wistar rats using the biochemical, heamatological and histopathological indices. Daily doses of 100, 200, 400 and 1000 mg/kg body weight of crude methanol extracts of M. oleifera leaves and seeds were administered orally to 8 groups of 5 rats per group each for 28 days. A control group of 5 rats was also included in the experiment. Heamatological, biochemical and histopathological indices were evaluated by standard methods. Data were analyzed using one way analysis of variance and statistically significant difference was considered at p<0.05, p<0.01 and p<0.001. Histopatho-logical changes were observed in the heart, liver, lungs, spleen and kidneys of rats treated with the extracts at all doses tested. Some other physical changes like agitation, confusion and disorientation were observed at the highest dose tested (1000 mg/kg) of the seed extract. A significant increase (p<0.05) in neutrophil, white blood cell (WBC) and platelet were observed. However, a significant decrease in aspartate amino transferase (AST), alanine amino transaminase (ALT), alkaline phosphatase, (ALP) was also observed. The results suggest that the leaf and seed extracts of M. oleifera could boost immunity and offer hepatoprotective effects

ON MATHEMATICAL MODEL FOR THE STUDY OF TRAFFIC FLOW ON THE HIGH WAYS

This paper presents mathematical model for the study of traffic flow on the highways. The effect of the density of cars on the overall interactions of the vehicles along a given distance of the road was investigated. We also observed that the density of cars per mile affects the net rate of interaction between them

Isolation of Chemical Compounds and Essential Oil from Agrimonia asiatica Juz. And Their Antimicrobial and Antiplasmodial Activities

© 2020 Raushan A. Kozykeyeva et al. Agrimonia asiatica is a perennial plant with deep green color and covered with soft hairs and has a slightly aromatic odor. This genus Agrimonia has been used in traditional medicines of China, Greece, and European countries. It was mainly used as a haemostatic, a tonic for asthenia, and an astringent for diarrhea. Agrimony is part of the division Magnoliophyta; class is represented by order Rosales, family Rosaceae, of the genus Agrimonia. Family Rosaceae - or pink eels - is one of the largest families of flowering plants, including about 100 genera and 3000 species. Rosaceae is common in almost all areas of the globe where flowering plants can grow, but most of them are concentrated in the temperate and subtropical zones of the Northern Hemisphere. Phytochemical investigation on ethanolic extract of A. asiatica led to isolation of four flavonoid derivatives (kaempferol-3-glycoside, quercetin-3-O-α-arabinofuranosyl-β-D-galactopyranoside, 3-O-kaempherol 2,3-di-O-acetyl-4-O-(cis-p-coumaroyl)-6-O-(trans-p-coumaroyl)-β-D-glucosopyranoside, and catechin) alongside of sucrose. All the extracts, fractions, and isolated compounds were tested for antimicrobial and antiplasmodial activities. We also studied the chemical composition of essential oil obtained from the aerial part of A. asiatica. The essential oil constituents from the aerial part of A. asiatica were obtained using a steam-distillation method in wild growing conditions in Kazakhstan. The essential oil extracted from the aerial part of the plant was analyzed by gas chromatography-mass spectroscopy and its major components amounting to 100% were found to be β-selinene (36.370%), α-panasinsene (21.720%), hexadecanoic acid (7.839%), and 1,2-nonadiene (6.199%). Neither the extract nor the isolated compounds showed antimicrobial and antiplasmodial activities

Effects of monoclonal anti-PcrV antibody on Pseudomonas aeruginosa-induced acute lung injury in a rat model

BACKGROUND: The effects of the murine monoclonal anti-PcrV antibody Mab166 on acute lung injury induced by Pseudomonas aeruginosa were analyzed in a rat model. METHODS: Lung injury was induced by the instillation of P. aeruginosa strain PA103 directly into the left lungs of anesthetized rats. One hour after the bacterial instillation, rabbit polyclonal anti-PcrV IgG, murine monoclonal anti-PcrV IgG Mab166 or Mab166 Fab-fragments were administered intratracheally directly into the lungs. The degree of alveolar epithelial injury, amount of lung edema, decrease in oxygenation and extent of lung inflammation by histology were evaluated as independent parameters of acute lung injury. RESULTS: These parameters improved in rats that had received intratracheal instillation of either rabbit polyclonal anti-PcrV IgG, murine monoclonal anti-PcrV IgG Mab166 or Mab166 Fab-fragments in comparison with the control group. CONCLUSION: Mab166 and its Fab fragments have potential as adjuvant therapy for acute lung injury due to P. aeruginosa pneumonia

Pegcetacoplan versus Eculizumab in Paroxysmal Nocturnal Hemoglobinuria

Background Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired disease characterized by chronic complement-mediated hemolysis. C5 inhibition controls intravascular hemolysis in untreated PNH but cannot address extravascular hemolysis. Pegcetacoplan, a pegylated peptide targeting proximal complement protein C3, potentially inhibits both intravascular and extravascular hemolysis. Methods We conducted a phase 3 open-label, controlled trial to assess the efficacy and safety of pegcetacoplan as compared with eculizumab in adults with PNH and hemoglobin levels lower than 10.5 g per deciliter despite eculizumab therapy. After a 4-week run-in phase in which all patients received pegcetacoplan plus eculizumab, we randomly assigned patients to subcutaneous pegcetacoplan monotherapy (41 patients) or intravenous eculizumab (39 patients). The primary end point was the mean change in hemoglobin level from baseline to week 16. Additional clinical and hematologic markers of hemolysis and safety were assessed. Results Pegcetacoplan was superior to eculizumab with respect to the change in hemoglobin level from baseline to week 16, with an adjusted (least squares) mean difference of 3.84 g per deciliter (P Conclusions Pegcetacoplan was superior to eculizumab in improving hemoglobin and clinical and hematologic outcomes in patients with PNH by providing broad hemolysis control, including control of intravascular and extravascular hemolysis. (Funded by Apellis Pharmaceuticals; PEGASUS ClinicalTrials.gov, NCT03500549. opens in new tab.