423 research outputs found

    Fixed Point in Minimal Spaces

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    This paper deals with fixed point theory and fixed point property in minimal spaces. We will prove that under some conditions f : (X,M) → (X,M) has a fixed point if and only if for each m-open cover {Bα} for X there is at least one x ∈ X such that both x and f(x) belong to a common Bα. Further, it is shown that if (X,M) has the fixed point property, then its minimal retract subset enjoys this property

    Survey of intestinal parasites of Neogobius bathybius in south-western coasts of the Caspian Sea

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    Neogobius bathybious fish were caught in south-western coastal waters of the Caspian Sea, from Anzali to Zibakenar, by bottom trawl. Fish specimens numbering 97 were examined for intestinal parasites and prevalence, intensity and dominance were calculated for each kind of parasites. Four different parasites were isolated from the fish including Dichelyne minutes which with %85.56 prevalence and %65.76 intensity was the most important infecting parasite. Corynosoma strumosum showed %51.54, Anisakis sp. %12.37 and Eustrogylides excises %1.03 prevalence as the other isolated parasites in fish

    Vilsmeier-Haack reagent: A facile synthesis of 2-(4-chloro-3,3-dimethyl-7-phenoxyindolin-2-ylidene)malonaldehyde and transformation into different heterocyclic compounds

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    2-(5-Chloro-2-phenoxyphenyl)hydrazine was converted to corresponding 3H-indole by Fischer method utilizing the isopropyl methyl ketone in acetic acid. The reaction of 3H-indole with Vilsmeier-Haack reagent furnished aminomethylene malonaldehyde in excellent yield while the reactions of malonaldehyde with hydrazine, arylhydrazines, amines, cyanoacetamide and hydroxylamine hydrochloride, led to the corresponding pyrazole derivatives, enamines, cyanopyridone, and cyanoacetamide derivatives respectively

    The first record of Pomphorhynchus laevis (Acanthocephala) in chub, Squalius cephalus (Linnaeus, 1758) from Gamasiab River, Hamedan, Iran

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    Pomphorhynchus laevis is a common fish parasite in Europe which has been reported from Acipenser stellatus, Barbus capito, Barbus lacerta, Barbus mursa and Onchorhynchus mykiss in Iran. In a survey on the aquaculture potential of Gamasiab River in Hamedan Province, endemic fish parasites were investigated in summer and autumn 2008. After recording biometric characteristics, common necropsy and parasitology methods were used. Live acanthocephalans were relaxed in distilled water at 4 ÂșC for 1 h and fixed in 10% hot buffered formalin. All specimens fixed in 10% formalin were stained with aqueous acetocarmine, dehydrated and mounted in Permount. The worms were identified using parasite identification keys. A total of 36 individuals of Chub, Squalius cephalus, were investigated and 459 individuals of Pomphorhinchus laevis were recovered from intestine of 32 fish specimens. The prevalence mean intensity and mean abundance of P. laevis were %88.9, 14.3 and 12.7, respectively. The maximum number of the parasite recorded in a five years old fish (403gr in weight) was 130 plerocercoids. Chub, Squalius cephalus, is reported for the first time as a new host record for P. laevis in Iran

    Occurrence and intensity of parasites in Prussian carp, Carassius gibelio from Anzali wetland, southwest Caspian Sea

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    The aim of this study was to detect the occurrence of parasites in Prussian carp, Carassius gibelio as the most important alien fish in Anzali international wetland. This undesirable fish was introduced accidentally to Iran with Chinese carp fries which imported to the country during the last decades and then acceded to Anzali wetland. Today this fish has significant stocks in Anzali wetland but there have been limited studies about the parasites of this fish in Anzali wetland. During this study a total of 90 Prussian carp were collected by electrofishing and gillnets from April through July 2012. After recording biometric characteristics, common necropsy and parasitology methods were used. A total of 2715 individuals out of 11 parasite species were recovered. Parasitofauna consisted of: two protozoans, Ichthyophthirius multifiliis and Trichodina sp.; one nematode, Raphidascaris acus; one trematode, Diplostomum spathaceum; six monogeneans, Dactylogyrus formosus, Dactylogyrus dulkeiti, Dactylogyrus baueri, Dactylogyrus arquatus, Dactylogyrus inexpectatus and Gyrodactylus kobayashii; and one crustacean, copepodid stage of Lernaea cyprinacea. The monogeneans had the highest prevalence values (88.89%). The occurrence of D. inexpectatus in C. gibelio is reported for the first time in Iran

    Culture of Chinese carps using anaerobic fermented cow manure (Slurry) and comparison of survival and growth factors versus traditional culture

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    The objective of this project is to compare growth and survival rate in Chinese carps reared under traditional culture conditions versus those reared in ponds treated with slurry (anaerobic fermented of cow manure). This experiment was conducted using two treatments one treatment using slurry and the other using cow manure plus chemical fertilizer as the control with three replicates for each. Chinese carp were stocked at the density of 2375 individuals/ha ( Silver carp 60%, Bighead 15%, common carp 17% and grass carp 8%). In this investigation common carp and grass carp were fed with formulated diets and fresh grass, respectively. The survival rate in the slurry treatment was higher than that in traditional treatment. Survival rates were 98, 100, 84 and 52 percent for silver carp, bighead, common carp and grass carp, respectively in the slurry treated ponds and 96.0, 98.3, 82.8 and 20.0% percent in the control ponds. The results showed that survival rate and yields were higher in the slurry treated ponds than that in the control. The increasing percent of yield were 13.5, 2.6, 18.4 and 85.3 in silver carp, bighead, common carp and grass carp, respectively. The survival rate for grass carp was two times higher in the slurry treatment than control. Zooplankton abundance in slurry ponds was higher than that in control, but blue-green algae density in slurry treated ponds was less than (over 50%). In general the results indicate that slurry with higher nutritional content is more effective on the survival and growth rate of fishes and also is more efficient in the proliferation of plankton in particular zooplankton. Slurry also reduces the use of chemical fertilizers

    An open source, parallel DSMC code for rarefied gas flows in arbitrary geometries

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    This paper presents the results of validation of an open source Direct Simulation Monte Carlo (DSMC) code for general application to rarefied gas flows. The new DSMC code, called dsmcFoam, has been written within the framework of the open source C++ CFD toolbox OpenFOAM. The main features of dsmcFoam code include the capability to perform both steady and transient solutions, to model arbitrary 2D/3D geometries, and unlimited parallel processing. Test cases have been selected to cover a wide range of benchmark examples from 1D to 3D. These include relaxation to equilibrium, 2D flow over a flat plate and a cylinder, and 3D supersonic flows over complex geometries. In all cases, dsmcFoam shows very good agreement with data provided by both analytical solutions and other contemporary DSMC codes

    The effect of anaerobic fermentation of cow manure on culture of Rutilus frisii Kutum and comparison of survival and growth factors versus traditional feeding

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    Rutilus firisii kutum is one of the important fish in Caspian Sea that has significant economical role to the region. The overall objective of the project is to compare the growth and survival of Rutilus frisii Kutum larvae under conventional conditions and conditions under use of organic fertilizer by anaerobic fermentation or slurry. This study was conducted in nine 1.7 hec pounds with 3 treatments with stocking densities of 1.7 million fish larva at Dr Yousefpoor Center at Siakal Village, 32km far from city of Rasht in North of Iran. The first treatment considered as control using concentrated food and grinded kilka fish. In the second treatment, the pound was supplied only by slurry for 13 days followed by concentrated fish food. The third treatment started with slurry for 13 days followed by slurry and concentrated food together. The physical and chemical parameters of water, plankton, biometry of fish, growth indices were monitored weekly. The result indicated that production was 1.7 to 2 times higher in slurry than traditional treatment also the survival rate was 1.7 times higher in slurry treatment. Slurry with several active substances is more effective and can promote the growth of zooplanktons that is the food for larval stage of Rutilus frisi kutum. Nutritional contents of phosphorous, nitrogen, calcium, magnesium, potassium, protein and lipid after anaerobic fermentation were higher in slurry treatment than control. The blue-green algae density in slurry pounds was less than control
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