14 research outputs found
Investigations on the age, growth and mortality parameters of Kawakawa, Euthynnus affinis (Cantor, 1849) from the North west coast of India
Kawakawa, Euthynnus affinis contributes to the tune of 35,466 tonnes forming 1% to the total marine fish landings of India. Investigations on growth and mortality were of this species carried out based on the length frequency data during 2008-2012. The length-weight relationship for the pooled samples were derived for intercept a=0.0286, slope b=2.857 and coefficient of determination r2=0.917. The values obtained for growth parameters of L∞ was 67.86 cm, for growth coefficient (K) 0.70 and for to -0.26y-1. The natural, total and fishing mortalities recorded as 0.86, 1.48 and 0.62 y-1,respectively. The exploitation ratio (F/Z) was observed as 0.42. The M/K ratio was estimated at 1.23. The average fork length of 46 cm and weight of 2024 g were estimated in the samples collected. The length at the end of 1st year to 5th year was observed to be 33, 52, 64, 70 and 75 cm, respectively. The fishing mortality derived in this study is more than the optimum and limit value indicated the sign of overexploitation
Poly Caprolactam Supported Hexaethylene Glycolic Imidazolium Ionic Liquid as a Heterogeneous Promoter for Nucleophilic Fluorination
Hexaethylene glycolic vinyl imidazolium (hexaEGVIM) was supported on N-vinyl caprolactam via covalent bonds through simple copolymerization to form poly caprolactam-supported hexaethylene glycol-substituted imidazolium salts (PCLS-hexaEGIM). The resulting heterogeneous PCLS-hexaEGIM promoter was active, selective, and stable for aliphatic nucleophilic substitution reactions using alkali metal salts. The alkali metal salts dramatically enhanced the reactivity of this heterogeneous catalyst with easily isolable higher product yields, reducing the formation of by-products. Therefore, nucleophilic fluorination and other substitution reactions can act as highly efficient catalysts in various sulfonyloxyalkanes and haloalkanes with regard to their corresponding fluorinated products
Solvent-free synthesis of α-aminophosphonates: Cellulose-SO3H as an efficient catalyst
α-Aminophosphonates possess a broad range of applications ranging from agrochemistry to medicine. We developed an efficient and eco-friendly Cellulose-SO3H catalyzed one-pot synthesis of α-aminophosphonates by three-component, room temperature reaction of an aldehyde, an amine and dialkylphosphite under solvent-free conditions. The major advantages of the present method are simple experimentation, use of inexpensive and eco-friendly reusable catalyst with good yields and short reaction times
Synthesis, characterization and evaluation of cytotoxicity of new aminophosphonic acid diesters in human leukemia cells
A series of novel fluoroaminophosphates 4a-4j were synthesized by one-pot method in presence of Tetramethylguanidine (TMG) as a catalyst and were characterized by elemental analysis, FTIR, 1H, 13C, 31P, 19F NMR and mass spectra. All the title compounds were evaluated for in vitro cytotoxicity against leukemic cell line derived from Tcells of leukemia patient (CEM cells) by Trypan blue exclusion and MTT assays, and these were found to exert concentration dependent cytotoxic effects. Among them 4f, 4g & 4j possessed marked cytotoxicity. 4g (with IC50 value of 6 iM) had emerged as lead compound
Common dolphinfish, Coryphaena hippurus, spawn at their easternmost Atlantic range adjacent to the Mediterranean Sea.
This study provides sound evidence of the spawning activity of common dolphinfish
(Coryphaena hippurus) in the Gulf of Cadiz (southwest Spain) during summer months.
Along with waters off CĂ´te d'Ivoire, this area adjacent to the Mediterranean Sea is
the easternmost Atlantic spawning ground documented for the species. All the fish
analysed (5 males and 15 females) were at spawning stage, except the smallest
female (61.5 cm in fork length), which might not have yet reached sexual maturation.
The oceanographic conditions during the samplings were similar to those occurring
during the peak spawning season in the Gulf of Mexico. The study results are consistent
with recent genetic studies indicating differentiation between Mediterranean
and Atlantic dolphinfish populations, with the Strait of Gibraltar representing a
boundary between two distinct reproductive units. The present results may contribute
to improve the understanding of the dynamics of dolphinfish population and the
management of eastern Atlantic and Mediterranean stocks.VersiĂłn del editor1,83