10 research outputs found

    Permutation based decision making under fuzzy environment using Tabu search

    Get PDF
    One of the techniques, which are used for Multiple Criteria Decision Making (MCDM) is the permutation. In the classical form of permutation, it is assumed that weights and decision matrix components are crisp. However, when group decision making is under consideration and decision makers could not agree on a crisp value for weights and decision matrix components, fuzzy numbers should be used. In this article, the fuzzy permutation technique for MCDM problems has been explained. The main deficiency of permutation is its big computational time, so a Tabu Search (TS) based algorithm has been proposed to reduce the computational time. A numerical example has illustrated the proposed approach clearly. Then, some benchmark instances extracted from literature are solved by proposed TS. The analyses of the results show the proper performance of the proposed method

    Prevalence of HIV infection and the correlates among homeless in Tehran, Iran

    No full text
    Objective: To determine the prevalence of HIV infection among homeless men and women and the related risk behaviors in Tehran, Iran. Methods: In 2007–2008, Tehran municipality stacked up 10672 homeless men and women for assessment of HIV and began collaboration with Iranian Research Center for HIV/AIDS (IRCHA) departments to conduct HIV infection prevalence surveys in homeless populations. The results were analyzed for associations with demographic information, family support, status of drug abuse and relation with family and friends. Results: Overall HIV prevalence was 1.7% (95% confidence interval 1.4–1.9). Factors independently associated with HIV infection included history of using drugs [AOR 8.15 (4.86–13.67)], older age [AOR 1.80 (1.08–2.99) for 40–55 yr], occupation [AOR 1.64 (1.19–2.24) for unemployed], and no relation with family [AOR 1.82 (1.30–2.54)]. Conclusions: This study supports the idea that injection drug use is contributing to the increased spread of HIV among Iranian homeless. Harm reduction programs should be expanded, particularly among homeless injection drug users

    Aerobic midgut microbiota of sand fly vectors of zoonotic visceral leishmaniasis from northern Iran, a step toward finding potential paratransgenic candidates

    No full text
    Abstract Background Leishmaniasis is caused by Leishmania parasites and is transmitted to humans through the bite of infected sand flies. Development of Leishmania to infective metacyclic promastigotes occurs within the sand fly gut where the gut microbiota influences development of the parasite. Paratransgenesis is a new control method in which symbiotic bacteria are isolated, transformed and reintroduced into the gut through their diet to express anti-parasitic molecules. In the present study, the midgut microbiota of three sand fly species from a steppe and a mountainous region of northern Iran, where zoonotic visceral leishmaniasis (ZVL) is endemic, was investigated. Methods Briefly, adult female sand flies was collected during summer 2015 and, after dissection, the bacterial composition of the guts were analyzed using a culture-dependent method. Bacterial DNA from purified colonies was extracted to amplify the 16S rRNA gene which was then sequenced. Results Three ZVL sand fly vectors including Phlebotomus major, P. kandelakii and P. halepensis were found in the highlighted regions. In total, 39 distinct aerobic bacterial species were found in the sand fly midguts. The sand fly microbiota was dominated by Proteobacteria (56.4%) and Firmicutes (43.6%). Bacterial richness was significantly higher in the steppe region than in the mountainous region (32 vs 7 species). Phlebotomus kandelakii, the most important ZVL vector in the study area, had the highest bacterial richness among the three species. Bacillus subtilis and Pantoea agglomerans were isolated from the guts of the sand flies; these are already used for the paratransgenesis of sand flies and mosquitoes, respectively. Conclusions The existence of B. subtilis and P. agglomerans in the ZVL vectors and other sand fly species studied so far suggests that these two bacterial species are potential candidates for paratransgenic approach to prevent ZVL transmission. Further research needs to test the possible relationship between the gut microbiome richness and the vector competence of the ZVL vectors

    Assessing the Fauna of Aquatic Insects for Possible Use for Malaria Vector Control in Large River, Central Iran

    No full text
    Insects with over 30,000 aquatic species are known as very successful arthropods in freshwater habitats. Some of them are applied as biological indicators for water quality control, as well as the main food supply for fishes and amphibians. The faunistic studies are the basic step in entomological researches; the current study was carried out emphasizing on the fauna of aquatic insects in Karaj River, northern Iran. A field study was carried out in six various sampling site of Karaj River during spring 2013. The aquatic insects were collected using several methods such as D-frame nets, dipping and direct search on river floor stones. Specimens were collected and preserved in Ethanol and identified by standard identification keys. Totally, 211 samples were collected belonging to three orders; Plecoptera, Trichoptera and Ephemeroptera. Seven genuses (Perla, Isoperla, Hydropsyche, Cheumatopsyche, Baetis, Heptagenia and Maccafferium) from five families (Perlidae, Perlodidae, Hydropsychidae, Batidae, Heptagenidae) were identified. The most predominant order was Plecoptera followed by Trichoptera. Karaj River is a main and important river, which provides almost all of water of Karaj dam. So, identification of aquatic species which exist in this river is vital and further studies about systematic and ecological investigations should be performed. Also, monitoring of aquatic biota by trained health personnel can be a critical step to describe water quality in this river. Understanding the fauna of aquatic insects will provide a clue for possible biological control of medically important aquatic insects such as Anopheles as the malaria vectors
    corecore