98 research outputs found

    Evaluating the bioaccumulation of nickel and vanadium and their effects on the growth of Artemia urmiana and A. franciscana

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    Although there is growing evidence that metals can be toxic to various aquatic species, there is still insufficient knowledge to integrate this information in environmental risk assessment procedures. In this study, we have investigated bioaccumulation and effects of nickel and vanadium on mortality and growth of Artemia urmiana and Artemia franciscana. The in 24 h of A. urmiana and A. franciscana exposed to nickel and vanadium were 0.0072, 0.0114 mg/l and 0.0107 and 0.011 mg/l respectively. In growth experiments, the length of animals was considered as growth index. Results indicates that the mean length of animals in (0.001, 0.002 and 0.003 mg/l) Ni and V on first, 5th, 7th and 11th days of life significantly decreases in comparison with control groups (p<0.05).Bioaccumulation of Ni and V in the same concentration, after 24 h in nauplius and also in adults of A. urmiana and A. fransicana were statistically significantly higher than of the control groups (P < 0.05). Both species accumulate nickel and vanadium in their bodies. However A. urmiana is more resistant to the heavy metals. Results show, nickel is less toxic than vanadium on Artemia

    Multicast Network Design Game on a Ring

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    In this paper we study quality measures of different solution concepts for the multicast network design game on a ring topology. We recall from the literature a lower bound of 4/3 and prove a matching upper bound for the price of stability, which is the ratio of the social costs of a best Nash equilibrium and of a general optimum. Therefore, we answer an open question posed by Fanelli et al. in [12]. We prove an upper bound of 2 for the ratio of the costs of a potential optimizer and of an optimum, provide a construction of a lower bound, and give a computer-assisted argument that it reaches 22 for any precision. We then turn our attention to players arriving one by one and playing myopically their best response. We provide matching lower and upper bounds of 2 for the myopic sequential price of anarchy (achieved for a worst-case order of the arrival of the players). We then initiate the study of myopic sequential price of stability and for the multicast game on the ring we construct a lower bound of 4/3, and provide an upper bound of 26/19. To the end, we conjecture and argue that the right answer is 4/3.Comment: 12 pages, 4 figure

    The study of cyst formation in bisexual strains of A. urmiana, A. franciscana and parthenogenetic strians of A. pakistan, A. turkmenistan in laboratory conditions

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    The study was conducted to achieve growth, survival and reproductive characteristics of four Artemia populations (A.urmiana , A.franciscana , Pakistan strain and Turkmanestan strain). In this study, The strains were cultured under the same and static environment in laboratory condition. All cysts strains were hatched using the standard methods and the nauplii from the populations were cultured in laboratory condition using 80 g/L salinity, 25±1ºC with photoperiod (12L:12D) and Dunalliella tertiolecta were fed. The growth and survival of artemia were determined on days 8, 11, 14, 17 and 20 of culture. Randomly, The adult population were placed in 50 ml conical falcons and reproductive characteristics were determined. The results revealed that the survivorship A. franciscana had the highest survival (%99.8) and A. turkmanestan lowest survival (%92.1) The results revealed that the in growth rate while pakistanian strain had the highest growth rate(8554 micron). The results revealed that the reproductive characteristics in each population of species , the highest cyst production were observed in A. urmiana, A. franciscana and A. turkmanestan strains and the highest nauplii production was due to pakistanian strain. The highest production were observed in A. franciscana and lowest production were observed in turkmanestan strain

    Effects of Artemia parthenogenetica culturing on socioeconomic development of the eastern marginal lands, Qom Salt Lake

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    Saltwater resources with Artemia (Brine shrimp) are the important ecosystems in Semi-arid Areas. That can play an important role in sustaining the economic and social system. Alternatively, will ensure that economic and social issues with of continuity and sustainability of these ecosystems resident. This study carried out "Effects of Artemia parthenogenetica culturing on socio-economic development of the eastern marginal lands, Qom Salt Lake" that was ordered by Qom province general directorate of fisheries during the 2012-2013. According to previous studies, despite the potential of human resources and Social conditions for the development of economic activities, factors such as the low groundwater and drying the salt lake , lack of fresh water in the region, environmental problems , successive droughts, prioritize and rationalize water use in agriculture, Artemia cyst harvest or Artemia culture has made virtually impossible with the current situation and has deprived the tools to make investments for the construction of earthen ponds and exploitation of native Artemia in the eastern margin of the Qom lake . Also, due to the occurrence of the Lake in the national park and privacy protection and Prohibited areas of environmental protection organization, it seems unlikely that this organization grant approval agreement required for any exploitation

    A Survey of Air-to-Ground Propagation Channel Modeling for Unmanned Aerial Vehicles

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    In recent years, there has been a dramatic increase in the use of unmanned aerial vehicles (UAVs), particularly for small UAVs, due to their affordable prices, ease of availability, and ease of operability. Existing and future applications of UAVs include remote surveillance and monitoring, relief operations, package delivery, and communication backhaul infrastructure. Additionally, UAVs are envisioned as an important component of 5G wireless technology and beyond. The unique application scenarios for UAVs necessitate accurate air-to-ground (AG) propagation channel models for designing and evaluating UAV communication links for control/non-payload as well as payload data transmissions. These AG propagation models have not been investigated in detail when compared to terrestrial propagation models. In this paper, a comprehensive survey is provided on available AG channel measurement campaigns, large and small scale fading channel models, their limitations, and future research directions for UAV communication scenarios

    [(18)F] fluoromisonidazole and [(18)F] fluorodeoxyglucose positron emission tomography in response evaluation after chemo-/radiotherapy of non-small-cell lung cancer: a feasibility study

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    BACKGROUND: Experimental and clinical evidence suggest that hypoxia in solid tumours reduces their sensitivity to conventional treatment modalities modulating response to ionizing radiation or chemotherapeutic agents. The aim of the present study was to show the feasibility of determining radiotherapeutically relevant hypoxia and early tumour response by ([(18)F] Fluoromisonidazole (FMISO) and [(18)F]-2-fluoro-2'-deoxyglucose (FDG) PET. METHODS: Eight patients with non-small-cell lung cancer underwent PET scans. Tumour tissue oxygenation was measured with FMISO PET, whereas tumour glucose metabolism was measured with FDG PET. All PET studies were carried out with an ECAT EXACT 922/47(® )scanner with an axial field of view of 16.2 cm. FMISO PET consisted of one static scan of the relevant region, performed 180 min after intravenous administration of the tracer. The acquisition and reconstruction parameters were as follows: 30 min emission scanning and 4 min transmission scanning with 68-Ge/68-Ga rod sources. The patients were treated with chemotherapy, consisting of 2 cycles of gemcitabine (1200 mg/m(2)) and vinorelbine (30 mg/m(2)) followed by concurrent radio- (2.0 Gy/d; total dose 66.0 Gy) and chemotherapy with gemcitabine (300–500 mg/m(2)) every two weeks. FMISO PET and FDG PET were performed in all patients 3 days before and 14 days after finishing chemotherapy. RESULTS: FMISO PET allowed for the qualitative and quantitative definition of hypoxic sub-areas which may correspond to a localization of local recurrences. In addition, changes in FMISO and FDG PET measure the early response to therapy, and in this way, may predict freedom from disease, as well as overall survival. CONCLUSION: These preliminary results warrant validation in larger trials. If confirmed, several novel treatment strategies may be considered, including the early use of PET to evaluate the effectiveness of the selected therapy

    Study of Leishmania pathogenesis in mice : experimental considerations

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    Although leishmaniases are endemic in 98 countries, they are still considered neglected tropical diseases. Leishmaniases are characterized by the emergence of new virulent and asymptomatic strains of Leishmania spp. and, as a consequence, by a very diverse clinical spectrum. To fight more efficiently these parasites, the mechanisms of host defense and of parasite virulence need to be thoroughly investigated. To this aim, animal models are widely used. However, the results obtained with these models are influenced by several experimental parameters, such as the mouse genetic background, parasite genotype, inoculation route/infection site, parasite dose and phlebotome saliva. In this review, we propose an update on their influence in the two main clinical forms of the disease: cutaneous and visceral leishmaniases
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