An efficient harris hawk optimization algorithm for solving the travelling salesman problem

Cluster Computing - Travelling Salesman Problem (TSP) is an Np-Hard problem, for which various solutions have been offered so far. Using the Harris Hawk Optimization (HHO) algorithm, this paper...     

Influence of three rates of salinity on okra plants (Abelmoschus esculentus L.) infected with root-knot nematode in vivo

A greenhouse experiment was carried-out to evaluate the effect of three rates of salinity as abiotic stress on okra plants (Abelmoschus esculentus) infected with the root-knot nematode (Meloidogyne incognita) as biotic stress. Plant lengths and weights were significantly (p?≤?0.05) reduced except root weight and there was a positive correlation between increasing the salinity concentration from 0.1 to 0.3% and increasing the rate of reduction in plant criteria. The number of J2 in soil, galls, and eggmasses were decreased linked to increased salinity rate as compared to nematode control treatment. However, peroxidase and catalase activities were significantly reduced linked to increasing the salinity concentration from 0.1 to 0.3%. There was no significant difference between total phenols at all treatments. Meanwhile, there was no significant improvement in N, P, and K contents whereas photosynthetic pigments (a, b) and carotene were significantly (p?≤?0.05) reduced by nematode infection and increasing the salinity rate from 0.1 to 0.3%.     

Isotope exchange in biochemical networks application of an electric circuit technique to a biological reaction system

Electric circuit techniques are employed to derive the kinetic equations for a class of reactions occurring in complex networks as encountered in cellular systems, namely, exchange at equilibrium. The equations connecting equilibrium velocities with kinetic parameters of individual steps of an enzymatic reaction are derived in three ways : by direct chemical considerations, by showing that a form of Kirchhoff's rules is valid for exchange at equilibrium, and by employing the device known in electricity as the delta-star transformation.     

Accumulation of plant galactolipid affects cell morphology of Escherichia coli

Monogalactosyldiacylglycerol (MGDG) is a major constituent of thylakoid membrane in chloroplasts. Therefore, it is considered to have an important role in the maintenance of the complicated structure of the thylakoid membrane. We have succeeded in cloning the enzyme for MGDG synthesis and overexpressed it in Escherichia coli. In this study we analyzed the morphology of the E. coli harboring the gene. The fatty acid composition of its membrane lipids did not differ between the wild type and transformant, except for the appearance of MGDG. However, transformant cells appeared to be elongated. DAPI staining revealed the entire intracellular region of filamentous cells to be stained; therefore, the elongation of the cells is probably due to a defect in cell division. Atomic force microscopy revealed that the transformant had a smooth but scratched surface. It was concluded that the excessive accumulation of a non-bilayer lipid, MGDG, interfered with the translocation of proteins across the plasma membrane, including those for cell division.     

Therapy of multiple myeloma

Multiple myeloma (MM) is a haematological malignancy characterised by the clonal expansion of malignant plasma cells within the bone marrow. It accounts for 10% of all haematological malignant diseases and 1% of all malignancies. The median age of patients at the time of the diagnosis is 70 years. The characteristic clinical features of MM are bone marrow failure, susceptibility to infections, bone pain, pathological bone fractures, hypercalcaemia, and renal failure. Though MM is currently incurable, the important progress in chemotherapy has resulted in an improvement in survival from a median of 7 months in the 1950-ies to about 3 years today. Advances in the diagnosis and in supportive treatment of infections, hypercalcaemia, and renal failure also contributed to the prolongation of survival. For decades, the gold standard of treatment had been oral melphalan alone or in combination with prednisolone. Combination chemotherapy has not improved overall survival (OS), but these regimens have led to the prolongation of event-free survival (EFS) and also to a better quality of life. High-dose chemotherapy with haemopoietic stem cell rescue resulted in a great improvement in EFS as well as OS. For those very few who have an HLA-compatible donor and are under 55, allogeneic bone marrow transplantation offers the best hope of survival but comes at a greatly increased risk of toxicity. There are conflicting data in the literature concerning the role of interferon-alpha; it seems to be able to prolong the duration of the plateau phase. Current treatment is moving towards an approach using sequential therapy. This involves induction therapy proceeding to high-dose chemotherapy with some form of stem-cell rescue. Bisphosphonates reduce hypercalcaemia, bone pain and can inhibit bone destruction. They also possess a direct antitumor activity. The better understanding of the pathomechanism of the disease gives the opportunity of the application of new therapeutic modalities such as antagonising the effect of interleukin-6 (IL-6), or idiotypic vaccination.     

Interaction of 75-106 actin peptide with myosin subfragment-1 and its trypsin modified derivative

To explore the role of a hydrophobic domain of actin in the interaction with a myosin chain we have synthesized a peptide corresponding to residues 75-106 of native actin monomer and studied by fluorescence and ELISA the interaction (13+/-2.6x10(-6) M) with both S-1 and (27 kDa-50 kDa-20 kDa) S-1 trypsin derivative of myosin. The loop corresponding to 96-103 actin residues binds to the S-1 only in the absence of Mg-ATP and under similar conditions but not to the trypsin derivative S-1. Biotinylated C74-K95 and I85-K95 peptide fragments were purified after actin proteolysis with trypsin. The C74-K95 peptide interacted with both S-1 and the S-1 trypsin derivative with an apparent Kd(app) of 6+/-1.2x10(-6) M in the presence or absence of nucleotides. Although peptide fragment I85-K95 binds to S-1 with a Kd(app) of 12+/-2.4x10(-6) M, this fragment did not bind to the trypsin S-1 derivative. We concluded that the actin 85-95 sequence should be a potential binding site to S-1 depending of the conformational state of the intact 70 kDa segment of S-1.     

Tissue-specific G1-phase cell-cycle arrest prior to terminal differentiation in Dictyostelium

The cell cycle status of developing Dictyostelium cells remains unresolved because previous studies have led to conflicting interpretations. We propose a new model of cell cycle events during development. We observe mitosis of about 50% of the cells between 12 and 18 hours of development. Cellular DNA content profiles obtained by flow cytometry and quantification of extra-chromosomal and chromosomal DNA suggest that the daughter cells have half the chromosomal DNA of vegetative cells. Furthermore, little chromosomal DNA synthesis occurs during development, indicating that no S phase occurs. The DNA content in cells sorted by fluorescent tissue-specific reporters indicates that prespore cells divide before prestalk cells and later encapsulate as G1-arrested spores. Consistent with this, germinating spores have one copy of their chromosomes, as judged by fluorescence in situ hybridization and they replicate their chromosomes before mitosis of the emergent amoebae. The DNA content of mature stalk cells suggests that they also attain a G1 state prior to terminal differentiation. As prestalk cells appear to be in G2 up to 22 hours of development, our data suggest that they divide just prior to stalk formation. Our results suggest tissue-specific regulation of G1 phase cell cycle arrest prior to terminal differentiation in Dictyostelium.     

Stent thrombosis in patients treated with thienopyridines: clinical description of 10 cases

Subacute stent thrombosis (SAST) is a major thrombotic complication of coronary stenting. Its occurrence has been substantially reduced by thienopyridine treatment. However, information on clinical profile of patients with SAST in clopidogrel era is limited. In order to define the incidence and factors predisposing to stent thrombosis, we analyzed the computerized angiographic database of three interventional cardiology centers. Out of a total number of 5903 percutaneous coronary interventions (PCIs) with stent implantation, we found 10 patients with SAST (0.17%). The indication for PCI was usually an early invasive approach (90%) during an acute coronary syndrome. All patients were treated with an apparently optimal antithrombotic regimen (90% received heparin or LMWH and 70% received IIb/IIIa receptor inhibitors and all given aspirin). In each of the patients, we could identify high-risk angiographic findings. SAST presentation was always clinically significant with definite myocardial infarction in 100% of cases. 80% of cases occurred during the first six days post PCI. Two patients had a recurrent event. Finally, despite earlier reports of atorvastatin-mediated inhibition of clopidogrel activation we did not find any patient with SAST taking both drugs. Thus, patients with stent thrombosis during thienopyridine treatment usually exhibit high-risk angiographic features. Prospective studies should be performed to elucidate drug interactions that may reduce clopidogrel efficacy and contribute to stent thrombosis.