59 research outputs found

    Short communication: Jellyfish of Khuzestan coastal waters and their impact on fish larvae populations

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    One of the most valuable groups in the food chain of aquatic ecosystems is zooplankton. A large portion of them are invertebrate organisms with great variety of forms and structure, size, habitat and food value. The term ‘jellyfish’ is used in reference to medusa of the phylum Cnidaria (hydromedusae, siphonophores and scyphomedusae) and planktonic members of the phylum Ctenophora (Mills, 2001). Jellyfish medusa is a zooplankton which is frequently present in coastal ocean waters and all marine habitats. They are also primary predators of other zooplanktons which have significant impact on abundance and diversity of zooplankton communities that are one of the key parts of the marine food web. Most jellyfish include Hydromedusae, Siphonophora and Scyphomedusae and planktonic Ctenophora, especially in the productive warm months (Brodeur et al., 1999). In recent years, the frequency of the jellyfish in many ecosystems has increased (Xian et al., 2005; Lynam et al., 2006)

    Optimization of UV/H2 O2 /Fe3 O4 process to remove aniline from aqueous solutions using central composite methodology

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    Aniline with a benzene ring in its structure is a toxic, carcinogenic and mutagenic compound that causes many diseases in humans. Various methods have been developed to remove this pollutant from the environment among which the advanced oxidation has been successful in obtaining higher aniline removal efficiency. In this study, a UV light and Fe3O4 nano catalyst were used to remove aniline. In this study, the efficiency of aniline removal was studied as a dependent variable and aniline, hydrogen peroxide and iron nano catalyst concentrations, time and pH were investigated as independent variables. The concentration of aniline was measured by spectrophotometer. The optimization of the process was determined using the response surface method design and the central composite design model. Design Expert software was used to analyze the data. The results showed that the aniline removal efficiency decreased with increase in nano-catalyst concentration, hydrogen peroxide concentration and time and decreased with increasing pH and aniline concentration. To achieve maximum efficiency (78.1%), the optimal values for pH; initial concentration; time; nanoparticle content and H2O2 content were 3.2; 101 mg L–1; 50 min; 0.45 g L–1 and 31.08 mmol L–1. The results showed that the photo-Fenton process has a desirable ability to remove aniline from aqueous solution at pilot scale. Therefore, it was suggested to study the efficiency of this process as one of the clean and environmentally friendly methods at full scale on real wastewate

    Synthesis, Characterization and Thermal Behavior of Four Arms Poly(L-lactide) via Ring Opening Polymerization

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    Four (4-arms, polyL-Lactide) were prepared by having different repeating units (10, 25, 50 and 100) from Erythritols and L-Lactide. The polymers were characterized by several methods as FT-IR, 1HNMR, 13CNMR, Gel Permission Chromatography and Scanning Electron Microscopy and finally their thermal stability was evaluated. The all characterization methods were confirmed the expected structure of prepared polymers, on the other hand the prepared polymers have a thermal stabilizing above 175° C, therefore, it is expected to be suitable for use in tissue engineering and drug release applications.   Keywords: poly L-Lactide, four arms, ring-opening polymerization, thermal behavior.

    Some Properties of Two-Fuzzy Metric Spaces

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    Abstract In this paper we have provided the set ( ) be the set of all fuzzy set is bounded functions and we introduced of the define a two-fuzzy metric and we've made some properties of these sets by studying the open and closed balls, as well as studied property fuzzy convergence and fuzzy closure set in the two-fuzzy metric space

    Investigation of non red tide occurrence causes in Khuzestan coastal waters

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    The monitoring of the harmful Alga blooms (Red tide) in the Khuzestan coastal waters Provinces was carried out monthly at 5 stations during 2010 to 2011. The results revealed that, Coclodinum polykrikoides blooms was not occurred during investigation times, Phytoplankton composition species were included of 45 species of diatoms (%91), 9 species of Dinoflgellates (7. 52%) and Cyanophytes with one species (1.88%). Furthermore significant different values of nutrients were recorded. Different values of NH4 were measured for different months. In total, the measured ratio of N: P in all months were lower than Redfield Ratio (16:1) in which subsequently the environmental condition was not suitable for bloom of C. polykrikoides

    Status of the tiger tooth croaker, Otolithes ruber (Schneider, 1801) and jinga shrimp, Metapenaeus affinis(H. Milne Edwards, 1837) stocks in Khouzestan coastal waters

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    Population dynamics parameters and exploitation ratio of Jinga Shrimp, Metapenaeus affinis were studied from Sep 2011 to Dec 2011 and data collected from two landing places (Hendijan and Lifee-Bosif). During the project, more than 2200 specimens of jinga shrimp were measured. The mean value of length for the male and female were calculated as 9.8±0.86, 10.24±1.18 and mean value of weight for the male and female was as 6.730±1.64, 8.14±2.90 respectively. The length-weight relation were calculated as TW=0.024TL2.24 (n=1084,R^2=0.71) for males, TW=0.011TL2.80 (n=1081,R^2= 0.81) for females also we found significant different level length-weight relation in P<0.05. The growth parameters of von Bertalanffy equation were as, L_∞: 14.73 and K: 1.1 and t0: -0.02. The estimated valve of total mortality, natural mortality, fishing mortality and exploitation ratio is Z: 4.35, M: 1.68, F: 2.67, E: 0.61 respectively. By using method analyses knife-edge selection, relative yield per recruitment (Y'/R) :0.014, relative biomass per recruitment, (B'/R) :0.085., Exploitation ratio maximum sustainable yield, Emax : 0.38; biological reference points for Jinga Shrimp stock was calculated. MSY and fmsy value was 600T and 46100day respectively. Result in this study showed exploitation ratio Jinga Shrimp stock is over fishing and decreases exploitation ratio proposed

    Difficulty in detecting discrepancies in a clinical trial report: 260-reader evaluation

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    Background: Scientific literature can contain errors. Discrepancies, defined as two or more statements or results that cannot both be true, may be a signal of problems with a trial report. In this study, we report how many discrepancies are detected by a large panel of readers examining a trial report containing a large number of discrepancies. Methods: We approached a convenience sample of 343 journal readers in seven countries, and invited them in person to participate in a study. They were asked to examine the tables and figures of one published article for discrepancies. 260 participants agreed, ranging from medical students to professors. The discrepancies they identified were tabulated and counted. There were 39 different discrepancies identified. We evaluated the probability of discrepancy identification, and whether more time spent or greater participant experience as academic authors improved the ability to detect discrepancies. Results: Overall, 95.3% of discrepancies were missed. Most participants (62%) were unable to find any discrepancies. Only 11.5% noticed more than 10% of the discrepancies. More discrepancies were noted by participants who spent more time on the task (Spearman’s ρ = 0.22, P < 0.01), and those with more experience of publishing papers (Spearman’s ρ = 0.13 with number of publications, P = 0.04). Conclusions: Noticing discrepancies is difficult. Most readers miss most discrepancies even when asked specifically to look for them. The probability of a discrepancy evading an individual sensitized reader is 95%, making it important that, when problems are identified after publication, readers are able to communicate with each other. When made aware of discrepancies, the majority of readers support editorial action to correct the scientific record

    An investigation of annual discards of the trawlers and gillnet in Khuzestan coastal water, northwest Persian Gulf

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    The main objective of this study was to describe and estimate the seasonal pattern of discarded fish in the waters of the Persian Gulf coast in Khuzestan. Data were collected from the fishing dhow with Khuzestan Fisheries partnership in fishing areas of Lifeh, Boseif, Khure-mussa and Bahrakan from October 2011 to September 2012. Discarded fish samples were included 109 species from 67 families, nearly 40 percent commercial and 60 percent of non-commercial species. Rayfish and catfish have been observed in most fishing nets. Average sizes of most species particularly bony fish were under 15 cm. The amount of discarded fish per unit of fishing effort was not significantly different between seasons. The highest portion of the catch belongs to rayfishes. Total discarded fishes of gillnets were estimated 3162 tones. Total weight of commercial fishes with small size in discarded fish was estimated 225 tones. The rate and ratio of discarded fish in total catch of gillnet was estimated 0.23 and 0.31 respectively. Chondrichthyes with 12 species and 60% of gillnet catch has the highest percentage of discarded fish of gillnet. High number of commercial species with small size could be due to nursery role of Khuzestan coastal waters. Trawl net has more impact on type and amount of discarded fish than moving gill net. According to different aquatic groups, the highest percentage of protein (77.84±2.088) in Perciformes belongs to Eupleurogrammus muticus and the lowest percentage (40.40±0.322) belongs to Liza klunzingeri, the most percentage of lipid was in Liza klunzingeri (33.78±0.277) and the lowest percentage was in Grammoplites suppositus (3.34±0.025), the highest and lowest percentage of ash (minerals) were in Cynoglossus arel and Acanthocephola abbreviate (28.14±.377) and oligo duvauceli (0.7±0.02) respectively. Therefore discarded fish have great potential in fulfilling nutritional requirements as fresh food (minimally processed) and with nutritional additives in forms of fish powder and fish oil and it can play an effective role in aquaculture development in the region

    Study on possible rehabilitation and recovery of Bandar Emam Region by reducing Nickel and Iron environmental pollutant using microorganisms

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    Influx of metallic pollutants such as iron and nickel into marine environment has been increased drastically in current era. Due to its harmful effects on living organisms, the aim of current thesis was isolation and identification of microorganisms which could reduce iron and nickel. In order to isolate bacterial strains resistant to iron and nickel, deposit samples were collected from five stations in Imam Khomeini Port cultured on BHI agar medium containing 1000 ppm of iron and 50 ppm of nickel and incubated for 24 hours in 30 oC. Endurance threshold of strains isolated to different concentrations of iron (1000- 15000 ppm) and nickel (100- 25000 ppm) in BHI broth medium were evaluated, the most resistant strains were selected and MIC and MBC were determined. Growth curve of selected strains in the presence and absence of iron and nickel were assessed by turbidity method. Along with above mentioned process, removal amount of metal by living cells and dead biomasses of selected strains were assessed by atomic absorption analysis and then 16S rRNA method was used to identify and approve the selected strains. Results of the current study were demonstrated that among of 16 and 12 resistant strains to nickel and iron, two selected strains (number16 and 7) as the most resistant strains had MIC and MBC (29800 and 29700) and (26300 and 26500), respectively. It should be mentioned that iron’s MIC was not assessable. Results of atomic absorption analysis was demonstrated that the highest amount of nickel reduction in a medium with concentration of 194 ppm and 71 ppm were 16.7% and 63% after 72 hours by selected strain number 16 respectively and in a medium containing 158 ppm iron, after 50 hours 8.4% by selected strain 7, while dead biomass of strain 16 reduced nickel to the amount of 40.6% and it reduced 21% and 4% of iron in solutions with 46 ppm and 792 ppm of iron. Results of molecular analysis demonstrated that strain 16 was Bacillus subtilis. In addition, Bacillus subtilis which has been isolated in this study with ability of nickel and iron removal is an appropriate candidate to be used in aquatic environments

    The role of intradiscal steroids in the treatment of discogenic low back pain

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    LBP is one of the most common reasons for visiting a doctor and is the most common cause of disability under age 45.Amongst a variety of etiologies, internal disc disruption (IDD) has been postulated as an important cause of low back pain. Treating discogenic low back pain continues to be a challenge to physicians. Inflammation, either from direct chemical irritation or secondary to an autoimmune response to the nucleus pulposus has been implicated as the primary pain source. Both steroids and non-steroidal anti-inflammatory drugs have partial effectiveness in treating pain associated with inflammation. Therefore, the rationale for using intradiscal steroids is to suppress the inflammation within the disc, thereby alleviating the patient’s symptoms. The goal of this article is to review the literature regarding the efficacy of intradiscal steroids to treat low back pain of discogenic origin
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