119 research outputs found

    (Tc) Technique for Finding Optimal Solution To Transportation Problem

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    Given the importance of increasing economic openness transport companies’ face various issues arising at present time, this required importing different types of goods with different means of transport. Therefore, these companies pay great attention to reducing total costs of transporting commodities by using numbers means of transport methods from their sources to the destinations. The majority of private companies do not acquire the knowledge of using operations research methods, especially transport models, through which the total costs can be reduced, resulting in the importance and need to solve such a problem. This research presents a proposed method for the sum of Total Costs (Tc) of rows and columns, in order to arrive at the initial solutions accepted by its algorithm and compare the solution with a set of solutions that were reached through classic methods studied previously. Moreover, this research aims to compare results obtained using the proposed method versus the optimal solution after testing using the modified distribution method (MODI), and the percentile deviation scale, these tests were used to measure the efficiency of the solution for the proposed method with the optimal solution. It was concluded that the proposed method is the easiest with the least iterations number of calculations, which in turn resulted in reaching the optimal solution in transporting the optimal quantities and reducing total costs of transportation from various sources to the requesting destinations. Thus, the proposed method can be used by the companies operating in importation-exportation field to find optimal solutions for the transportation of various commodities. Key words: Total cost, Optimal Solution, Transportation problem, Degeneracy

    DNA sequence-selective C8-linked pyrrolobenzodiazepine-heterocyclic polyamide conjugates show anti-tubercular-specific activities.

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    New chemotherapeutic agents with novel mechanisms of action are in urgent need to combat the tuberculosis pandemic. A library of 12 C8-linked pyrrolo[2,1-c][1,4]benzodiazepine (PBD)-heterocyclic polyamide conjugates (1-12) was evaluated for anti-tubercular activity and DNA sequence selectivity. The PBD conjugates were screened against slow-growing Mycobacterium bovis Bacillus Calmette-Guérin and M. tuberculosis H37Rv, and fast-growing Escherichia coli, Pseudomonas putida and Rhodococcus sp. RHA1 bacteria. DNase I footprinting and DNA thermal denaturation experiments were used to determine the molecules' DNA recognition properties. The PBD conjugates were highly selective for the mycobacterial strains and exhibited significant growth inhibitory activity against the pathogenic M. tuberculosis H37Rv, with compound 4 showing MIC values (MIC=0.08 mg l-1) similar to those of rifampin and isoniazid. DNase I footprinting results showed that the PBD conjugates with three heterocyclic moieties had enhanced sequence selectivity and produced larger footprints, with distinct cleavage patterns compared with the two-heterocyclic chain PBD conjugates. DNA melting experiments indicated a covalent binding of the PBD conjugates to two AT-rich DNA-duplexes containing either a central GGATCC or GTATAC sequence, and showed that the polyamide chains affect the interactions of the molecules with DNA. The PBD-C8 conjugates tested in this study have a remarkable anti-mycobacterial activity and can be further developed as DNA-targeted anti-tubercular drugs

    Petroleum Ether and Chloroform Soluble Fractions of Whole Plant Extract of Acanthus ilicifolis Linn. Possesses Potential Analgesic and Antioxidant Activities.

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    Background: Medicinal plants are the major sources of traditional treatment of disease and new drug discovery due to major side effects of synthetic drug. Objectives: The aim of study was to evaluate analgesic and antioxidant activities of petroleum ether and chloroform soluble fractions of whole plant extract of Acanthus ilicifoius. Materials and Methods: The plant extract, standard diclofenac, and distilled water as control was administered post orally in Swiss albino mice and observe the analgesic activity by acetic acid (0.6%) induced writhing method. The plant extract was also subjected to perform reducing power assay, DPPH free radical scavenging activity, and FRAP assay to evaluate antioxidant activity. Results: The pet ether, and chloroform soluble fraction of plant extract revealed significant analgesic activity on mice model. Notably, the pet ether and chloroform fraction showed (40.14 ± 2.32) % and (40.12 ± 0.9) % analgesic inhibition, whereas standard diclofenac revealed (52.79 ± 2.62) % analgesic inhibition. In antioxidant activity assay, the plant extract showed mild to moderate antioxidant activities compare to standard ascorbic acid. Conclusion: From the results, it could be concluded that, the pet ether and chloroform fractions of whole plant extract of A. ilicifolius possesses potential analgesic and antioxidant properties

    Models for short term malaria prediction in Sri Lanka

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    <p>Abstract</p> <p>Background</p> <p>Malaria in Sri Lanka is unstable and fluctuates in intensity both spatially and temporally. Although the case counts are dwindling at present, given the past history of resurgence of outbreaks despite effective control measures, the control programmes have to stay prepared. The availability of long time series of monitored/diagnosed malaria cases allows for the study of forecasting models, with an aim to developing a forecasting system which could assist in the efficient allocation of resources for malaria control.</p> <p>Methods</p> <p>Exponentially weighted moving average models, autoregressive integrated moving average (ARIMA) models with seasonal components, and seasonal multiplicative autoregressive integrated moving average (SARIMA) models were compared on monthly time series of district malaria cases for their ability to predict the number of malaria cases one to four months ahead. The addition of covariates such as the number of malaria cases in neighbouring districts or rainfall were assessed for their ability to improve prediction of selected (seasonal) ARIMA models.</p> <p>Results</p> <p>The best model for forecasting and the forecasting error varied strongly among the districts. The addition of rainfall as a covariate improved prediction of selected (seasonal) ARIMA models modestly in some districts but worsened prediction in other districts. Improvement by adding rainfall was more frequent at larger forecasting horizons.</p> <p>Conclusion</p> <p>Heterogeneity of patterns of malaria in Sri Lanka requires regionally specific prediction models. Prediction error was large at a minimum of 22% (for one of the districts) for one month ahead predictions. The modest improvement made in short term prediction by adding rainfall as a covariate to these prediction models may not be sufficient to merit investing in a forecasting system for which rainfall data are routinely processed.</p

    Comparison of HER-2 overexpression in primary breast cancer and metastatic sites and its effect on biological targeting therapy of metastatic disease

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    HER-2 overexpression, a predictive marker of tumour aggressiveness and responsiveness to therapy, occurs in 20–30% of breast cancer. Although breast cancer is a heterogeneous disease, HER-2 measurement is carried out in primary tumour. This study aims to evaluate HER-2 overexpression in primary and metastases and its effect on treatment decisions. Biopsies from primary breast cancer and corresponding metastases from 58 patients were studied. HER-2 overexpression was evaluated immunohistochemically in all primary and metastatic sites. Positive overexpression in primary and/or metastases was confirmed by fluorescence in situ hybridisation (FISH). Discordance in HER-2 overexpression between primary and metastatic sites was 14% (eight of 58 patients). Concordance was found in 50 (86%) of patients (95% CI: 77–95). In one patient (2%), HER-2 was negative in metastasis but positive in primary. In seven (12%) patients, HER-2 was positive in metastases and negative in primary (95% CI: 3.7–20), and three of them responded to trastuzumab. Gene amplification by FISH was found in all cases with HER-2 positive (+2 and +3) by immunohistochemistry. Our data suggest that a possible discordance of HER-2 overexpression between primary and metastases should be considered when making treatment decisions in patients with primary HER-2-negative tumours

    Can gold be used as a hedge against the risks of Sharia-compliant securities? Application for Islamic portfolio management

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    In this paper, we investigate whether gold hedges Sharia-compliant stocks and Sukuk during the period from September 2005 to October 2017. The inference is taken by using both the DCC-GARCH model and the wavelet coherence analysis. On the whole, our finding suggests that gold is not effective in hedging the fluctuations of Sharia-compliant securities. However, we find that combining gold with stocks (and Sukuk) is useful in diversification and portfolio optimization. These results imply that, while gold is an excellent hedge for plain vanilla securities, it is not for Islamic exposures. This is important in light of the increasing amount of assets that are managed according to Islamic screening
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