38 research outputs found
Management of shrimp resources the Persian Gulf (I.R. IRAN) 
Shrimp is one of the most valuable marine products. Industrial exploitation of the Persian Gulf shrimp resources of Iran began in 1959. Long coastal areas of Iran provides half of the total shrimp stocks in the Persian Gult region. in the early years of the commercial exploitation of shrimp resources, the rich stocks supported annual catches per boat of upto 118 tons of unneaded shrimps But, the increase in industrial fishing vessels as well as in small wooden vessels has caused progrsively reduced catches every year after to date. Although introduction of restrictive measures, such as, closed fishing seasons, improved resources magnitude mean annual catches of industrial vessels per boat hasfallen upto 17 tons per year. In this survey, the increasing number of industrial fishing vessels serving shrimp iridustry of Iran and the subsequent reduction in the annual catch of shrimp is analyzed and several recommendations for better management of shrimp resources are presented.....
Information disclosure and dynamic climate agreements: shall the IPCC reveal it all?
This paper examines the role of public information communication in dynamic self-enforcing climate
agreements. We consider a framework with implicit contracts but also a dynamic coalition formation
context. In a stochastic game, where the social cost of Greenhouse Gasses (GHG) is an unknown
random variable, an information sender, such as the Intergovernmental Panel on Climate Change
(IPCC), controls the release of verifiable information about the unknown state variable to the countries.
The equilibrium communication strategy of the IPCC takes a threshold form, above which the IPCC
reveals all the information available, even if it hurts the prospect of approaching the socially optimum
level of emissions. The case where the IPCC remains silent, below the threshold, vanishes as the sender
gets perfectly informed about the underlying social cost
EXTRACTION OF ASTAXANTHIN ESTERS FROM SHRIMP WASTE BY CHEMICAL AND MICROBIAL METHODS
The carotenoid pigments specifically astaxanthin has many significant
applications in food, pharmaceutical and cosmetic industries. The goal
of this research was the extraction of Astaxanthin from a certain
Persian Gulf shrimp species waste (Penaeus semisulcatus), purification
and identification of the pigment by chemical and microbial methods.
Microbial fermentation was obtained by inoculation of two Lactobacillus
species Lb. plantarum and Lb. acidophilus in the medium culture
containing shrimp waste powder by the intervention of lactose sugar,
yeast extract, the composition of Both and the coolage (-20°C).
The carotenoids were extracted by an organic solvent system. After
purification of astaxanthin with the thin layer chromatography method
by spectrophotometer, NMR and IR analysis the presence of astaxanthin
esters was recognized in this specific species of Persian Gulf shrimp.
Results obtained from this study showed that the coolage at –20
°C not only does not have an amplifying effect on the production
of astaxanthin but also slightly reduces this effect. Also the effect
of intervention of lactose sugar showed more effectiveness in producing
astaxanthin than yeast extract or more than with the presence of both.
The results also indicated that there is not much difference in the
ability of producing the pigment by comparing both Lb. plantarum and
Lb. acidophillus. Also results showed the microbial method of
extraction of astaxanthin is more effective than chemical method. The
pigment extracted from certain amount of shrimp powder, 23.128 mg/g,
was calculated
Synthesis and In Vitro Cytotoxic Activity of 2-Amino-7-(dimethylamino)-4-[(trifluoromethyl)phenyl]-4H-chromenes
Three 2-amino-4-(trifluoromethylphenyl)-3-cyano-7-(dimethylamino) -4H-chromene derivatives were synthesized and their cytotoxic activities were determined against six human tumor cell lines using MTT assay. Condensation of 3-(dimethylamino)phenol, trifluoromethybenzaldehydes and malonitrile in ethanol containing piperidine afforded corresponding chromenes (4a-c). The structure of the synthesized compound was confirmed by 1H NMR, IR and Mass spectral data. Among compounds tested, 3-trifluoromethyl analogue (3b) was the most active against all human tumor cell lines (IC50=12-45 nM)
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Discordance in categorization of acute-on-chronic liver failure in the United Network for Organ Sharing database
Studies regarding acute-on-chronic liver failure (ACLF) among liver transplant (LT) candidates from the United Network for Organ Sharing (UNOS) database are being used to inform LT policy changes worldwide. We assessed the validity of identifying ACLF in UNOS.
We performed stratified random sampling among 3 US LT centers between 2013-2019 to obtain a representative patient sample across ACLF grades. We compared the concordance of ACLF classification by UNOS vs. blinded manual chart review, according to EASL-CLIF.
Among 481 sampled LT registrants, 250 (52%) had no ACLF, 75 (16%) had ACLF grade 1, 79 (16%) had ACLF grade 2, and 77 (16%) had ACLF grade 3 per UNOS categorization. Concordance of ACLF grade by UNOS vs. chart review was: 72%, 64%, 56%, and 64% for no ACLF, grade 1, grade 2, and grade 3, respectively, with an overall Cohen’s kappa coefficient of 0.48 (95% CI 0.42–0.54). Absence of acute decompensation was the most common reason for overestimation, and discordant brain and respiratory failure categorization were the most common reasons for underestimation of ACLF by UNOS.
In this retrospective multi-center study, ACLF categorization by UNOS showed weak agreement with manual chart review. These findings are informative for ongoing allocation policy discussions, highlight the importance of prospective studies regarding ACLF in LT, and should encourage UNOS reform.
Acute-on-chronic-liver-failure (ACLF) is a specific and common form of liver failure associated with high death rates. Studies have been published using the United States transplant registry (UNOS) to identify and describe outcomes of transplant candidates and recipients with ACLF, and these data are driving policy changes for transplant allocation around the world, but nobody has shown whether these data are reliable. We found that UNOS was not categorizing ACLF in concordance or accurately when compared to chart review, which shows the need for UNOS reform and non-UNOS studies to appropriately inform policies regarding the transplantation of patients with ACLF.
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•UNOS studies on ACLF are informing global transplant allocation policies, but the validity of these data is unknown.•We found that ACLF identified by UNOS is only weakly concordant with chart review.•Classification of acute decompensation and brain/respiratory failures are common sources of discordance.•These data highlight the importance of prospective studies regarding ACLF in LT and should encourage UNOS reform