Denitrification of recirculated aquaculture system effluents using fish sludge as primary substrate

Recirculating Aquaculture System (RAS) is a technology in which water is reused after different biological and mechanical treatment steps in fish farming. RAS produces a nitrate rich water effluent containing approximately 70-100 mg NO3/l, and a typical plant will have to offload between 50-100 kg NO3-N/d which needs to be denitrified before release to the marine environment to avoid eutrophication. Denitrification is a heterogenic process whereby reduced substrates (primarily organic, but also some reduced inorganic salts, like H2S and Fe2+, may serve as electron donors) are oxidized anoxically by reduction of NO3 and NO2 to N2. Organic substrates may come from external sources (easily biodegradable substrateslike acetate or methanol) or from internal, like the collected fish waste sludge containing feces and feed pellet residuals. Fish waste sludge is mainly particulate slowly biodegradable, and hydrolysis is necessary for use as C-source for denitrification. Fish sludge has been considered waste in the fish farming industries. Therefore, it is free, and applying it to run RAS is a resource recovery process. The kinetics (reaction rate) of denitrification using fish sludge is dependent on the chemical oxygen demand (COD) level; slowly biodegradable CODs (sbCODs) should be converted to readily biodegradable CODs (rbCODs) to provide the nitrate uptake process. Raw fish sludge was step-fed once or twice a day to a batch reactor containing substrate adapted activated sludge loaded with an initial nitrate concentration of 360 mg/l. Fish sludge characterization wet analysis was done on three different sludge batches and were compared. Two fermentation tests at 12 and 20 ℃ were done on fish sludge to investigate the effect of fermentation on biodegradability of fish sludge. Biomass specific nitrate uptake rates (NUR) were measured by an ion selective electrode, and substrate degradability and was estimated. NUR was also estimated using an equivalent initial COD concentration of acetate, and maximum NUR rates using fish sludge and fermented fish sludge were evaluated relative to the acetate driven denitrification rate. Fish sludge COD were split into three biodegradable fractions (easily biodegradable, slowly biodegradable, and slowly biodegradable particulate) based on NUR profiles, and their corresponding COD estimated using typical denitrifying yield factors. The observed acetate specific denitrification rate was 3.64 mg NO3-N/g VSS. h while the fish sludge rates were estimated to 1.2, 0.9 and 0.2 mg NO3-N/g VSS. h for the easily, slowly, and particulate degradable COD fractions respectively. Additionally, the effect of fermentation during anaerobic storages (over seven days) on sludge characteristics and volatile fatty acid production was investigated and the specific denitrification rate of settled and supernatant fermented sludge for easily degradable CODs was 3 and 2.2 mg NO3-N/g VSS. h. We conclude that direct use of fish sludge for denitrification of RAS effluents is possible, but design and operation would have to allow for the relative slow kinetics of the process, hypothetically limited by hydrolysis of slowly biodegradable dissolved and particulate COD fractions, which could be accelerated through fermentation

Renewable Energy Sources and Analyzing the Wind Turbine Performance; a Review

The potential of renewable energy resources has been investigated and its is shown that they can in fact fulfill most of the world’s energy demand. In this study renewable energy sources such as biomass, solar, wind, geothermal and hydropower are studied and provided with sustainable energy services, based on the available natural resources. In the past three decades wind and solar power system have developed rapidly in sales, while there was a decline in their capital cost and costs of electricity generated. This study shows that the transition to renewable –based energy systems are increasing and continues to improve their performance characteristic. The enhancement and utilization of renewable energy sources can increase diversity in energy supply market, help to secure long term supportable energy supplies, keeping the environment clean by reducing local and global atmospheric emissions, establish marvelous options too encounter specific energy service needs by helping to create new job opportunities especially in developing countries.The potential of renewable energy resources has been investigated and its is shown that they can in fact fulfill most of the world’s energy demand. In this study renewable energy sources such as biomass, solar, wind, geothermal and hydropower are studied and provided with sustainable energy services, based on the available natural resources. In the past three decades wind and solar power system have developed rapidly in sales, while there was a decline in their capital cost and costs of electricity generated. This study shows that the transition to renewable –based energy systems are increasing and continues to improve their performance characteristic. The enhancement and utilization of renewable energy sources can increase diversity in energy supply market, help to secure long term supportable energy supplies, keeping the environment clean by reducing local and global atmospheric emissions, establish marvelous options too encounter specific energy service needs by helping to create new job opportunities especially in developing countries

Investigating the Effect of Investors' Behavior and Management on the Stock Returns: Evidence from Iran

The purpose of the present study is to investigate the effect of behavioral variables on overconfidence in management, herding behavior and investors' emotional tendency on stock return. To this end, by using the data of firms listed in the Iran's Stock Exchange during the seven-year period of 2010-2016, overconfidence index in management, the herding behavior of the investors and the emotional tendency of the investors were calculated and their impact on stock return was examined. The data of the research are of a panel type and for analyzing the data and testing the hypotheses; a multiple linear regression model has been used. Evidence from the experimental results of the research showed that the behavioral variables studied in the research has a significant and inverse effect on the stock return of the companies

A framework for organizing cancer-related variations from existing databases, publications and NGS data using a High-performance Integrated Virtual Environment (HIVE)

Years of sequence feature curation by UniProtKB/Swiss-Prot, PIR-PSD, NCBI-CDD, RefSeq and other database biocurators has led to a rich repository of information on functional sites of genes and proteins. This information along with variation-related annotation can be used to scan human short sequence reads from next-generation sequencing (NGS) pipelines for presence of non-synonymous single-nucleotide variations (nsSNVs) that affect functional sites. This and similar workflows are becoming more important because thousands of NGS data sets are being made available through projects such as The Cancer Genome Atlas (TCGA), and researchers want to evaluate their biomarkers in genomic data. BioMuta, an integrated sequence feature database, provides a framework for automated and manual curation and integration of cancer-related sequence features so that they can be used in NGS analysis pipelines. Sequence feature information in BioMuta is collected from the Catalogue of Somatic Mutations in Cancer (COSMIC), ClinVar, UniProtKB and through biocuration of information available from publications. Additionally, nsSNVs identified through automated analysis of NGS data from TCGA are also included in the database. Because of the petabytes of data and information present in NGS primary repositories, a platform HIVE (High-performance Integrated Virtual Environment) for storing, analyzing, computing and curating NGS data and associated metadata has been developed. Using HIVE, 31 979 nsSNVs were identified in TCGA-derived NGS data from breast cancer patients. All variations identified through this process are stored in a Curated Short Read archive, and the nsSNVs from the tumor samples are included in BioMuta. Currently, BioMuta has 26 cancer types with 13 896 small-scale and 308 986 large-scale study-derived variations. Integration of variation data allows identifications of novel or common nsSNVs that can be prioritized in validation studies

A conventional PCR for differentiating common taeniid species of dogs based on in silico microsatellite analysis

Canine taeniids are among the major tapeworms with remarkable medical and economic significance. Reliable diagnosis and differentiation of dog taeniids using simple and sensitive tools are of paramount importance for establishing an efficient surveillance system. Microsatellites as abundant unique tandem repeats of short DNA motifs are useful genetic markers for molecular epidemiological studies. The purpose of the present study was to find a primer pair for rapid differentiation of major tapeworms of dogs, Taenia hydatigena, T. multiceps, T. ovis and Echinococcus granulosus, by screening existing nucleotide data. All the mitochondrial genome records as well as non-coding ITS1 sequences of Taeniidae species were downloaded from Nucleotide database from NCBI. For prediction and analysis of potential loci of STR/SSR in ITS1 as well as mitochondrial regions, we used ChloroMitoSSRDB 2.0 and GMATo v1.2. software. Different tapeworm species were categorized according to different motif sequences and type and size of each microsatellite locus. Three primer sets were designed and tested for differentiating taeniid species and evaluated in a conventional PCR system. Four taeniid species were successfully differentiated using a primer pair in a simple conventional PCR system. We predicted 2-19 and 1-4 microsatellite loci in ITS1 and mitochondrial genome, respectively. In ITS1, 41 Di and 21 Tri motifs were found in the taeniids while the majority of the motifs in the mitochondrial genome were Tetra (89) and Tri (70). It is documented that the number and diversity of microsatellite loci is higher in nuclear ITS1 region than mostly coding mitochondrial genome