994 resultados para Career changes


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Penaeus monodon juveniles were reared on semipurified diets containing various carbohydrates (maltose, sucrose, dextrin, molasses, cassava starch, corn starch or sago palm starch). Significant differences were observed between the type as well as the level of carbohydrate in the diet on the survival of the juveniles. Results indicate that there does not seem to be any correlation between survival and the complexity of the carbohydrates.

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The objective was to study dynamic changes of ovaries in rhesus macaques stimulated by gonadotropins to identify an indicator for predicting ovarian response to stimulation. Twenty-one cycling monkeys were given 36 IU/d recombinant human follicle-stimulat

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Formaldehyde is a very reactive compound capable of interacting with many functional groups of proteins including intermolecular and intramolecular cross-links of the molecules. The formation of cross-linking bonds may induce conformational change in proteins that favor further interaction of functional and hydrophobic groups. Formaldehyde which has been using illegally as a chemical preservative by some fish traders in our country. A study was carried out to determine the effects of irradiation (1.5 KGy) on formaldehyde concentration and nutritional (protein and lipid) changes of formalin (37% formaldehyde) treated fish (fresh) samples and found that the concentration of formaldehyde both in treated samples (0.37% formalin and 0.37% formalin with 1.5 KGy irradiation) were 37.0 µg/gm and 36.75 µg/gm. On the other hand, the amount of protein and lipid in treated samples before radiation (14.56% and 3.49%) and after radiation (14.15% and 3.25%). That means, radiation has no effect on the change of protein, lipid and formaldehyde.

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An investigation was carried out on the quality changes of Catla (Catla calla) stored immediately (0 h) in ice, after 6 hours in ice and at ambient temperature. The samples were examined for organoleptic and microbiological parameters in summer. Organoleptically, the acceptability of fish varied between 16-20 days in both the iced storage conditions and 12-13.5 hours at ambient temperature (28°C). When fish were organoleptically just acceptable on the 16th day of storage, bacterial load were 6.23 and 6.17 log10 cfu/g, respectively for 0 hour and after 6 hours iced fish. But on the 20th day of storage, when fish were just unacceptable SPC were 6.51 and 6.62 log10 cfu/g. In case of ambient temperature storage condition standard plate count was 8.36 log10 cfu/g on 13.5 hours, when fish were organoleptically just unacceptable. At the time of rejection for fish stored in ice (0 hour and after 6 hours) on 20th day, gram negative and gram positive values were 55.45%, 44.55% and 44.52%, 55.48% respectively. While fish were rejected after 13.5 hours at ambient temperature gram negative and gram positive bacteria were found as 43.02% and 56.98%. The differences in SPC, gram positive and gram negative bacteria between the storage times were statistically significant (p<0.05).

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Gamma radiation (3, 6 and 9 kGy) in combination with low temperature (-20°C) were applied to retain the quality and shelf-life of shrimp, Penaeus monodon for a longer period. The quality was assessed by monitoring the chemical (TVN, TMA) and sensory changes in irradiated and non-irradiated (control) samples. Among chemical indicators of spoilage, total volatile nitrogen (TVN) values for irradiated shrimps were found to be 2.26, 2.18 and 1.57 mg N/100g of sample at 3, 6 and 9 kGy respectively after 90 days whereas for non-irradiated samples it was found 2.45mg N/100 g of sample. Trimethylamine (TMA) value for non-irradiated samples after 90 days were found 2.30mg N/100 g sample whereas that for irradiated shrimps at 3, 6 and 9 kGy were found to be 2.10, 2.08 and 1.98 mg N/100 g sample respectively. The sensory scores of control sample were gradually decreased with the progress of storage period. From this study, it was clear that gamma radiation in combination with low temperature showed shelf-life extension (90 days) in each dose of radiation used but during the use of 9 kGy radiation, P. monodon showed best quality.

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Studies were conducted to know the effects of alum on the histological changes of silver barb (Barbodes gonionotus) fry in the aquarium. The use of up to 0.5 g/L of alum for 120 hours as means of treatment of fish diseases is safe. At this level, no abnormal behavior and pathological alteration were observed in the organs of experimental fish. As the doses increased to 1.25 g/L and above (1.5 g/L), experimental fishes exhibited abnormal movement and with marked histopathological changes in the various organs. A dose of above 0.5 g/L should be strictly prohibited.

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In this study gamma radiation (3, 6 and 9 kGy) in combination with low temperature (-20°C) were applied to retain the quality and shelf-life of shrimp, Penaeus monodon for a longer period. The quality was assessed by monitoring microbiological changes (TBC, TMC, TYC, TCC and Salmonella count) in irradiated and non-irradiated (control) samples. Among microbiological indicators of spoilage, total bacterial count (TBC) values for irradiated shrimps were found to be 1875, 1625 and 1525 cfugˉ¹ of sample at 3, 6 and 9 kGy respectively after 90 days whereas for non-irradiated samples it was found 2475 cfugˉ¹ of sample. Total moulds count (TMC) value for non-irradiated samples after 90 days were found 425 cfugˉ¹ sample whereas that for irradiated shrimps at 3, 6 and 9 kGy were found to be 275, 250 and 200 cfugˉ¹ sample respectively. Total yeast count (TYC) value for non-irradiated samples after 90 days were found 4125 cfugˉ¹ sample whereas that for irradiated shrimps at 3, 6 and 9 kGy were found to be 2850, 2150 and 1725 cfugˉ¹ sample respectively. Total coliform count and Salmonella count showed that those were absent during 90 days storage period. From this study, it was clear that gamma radiation in combination with low temperature showed shelf-life extension (90 days) in each dose of radiation used but during the use of 9 kGy radiation, Penaeus monodon showed best quality.

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This study was under taken at Karoun Lake Dam No.4. (Southwest of Iran). Water samples were collected from March 2012 to February 2013 in three selected silts. Environmental parameters and chlorophyll a concentration were measured, as well as identification and abundance of Phytoplankton communities were studied. According to this study, 30 species of Phytoplankton were identified at four seasons. Most abundance was related to the phyla Bcillariphyta (17 species), Chlorophyta (6 species), Crysophyra (4 species), Dinophyta (2 species) and Cyanophyta (1 species) respectively. The results showed, the maximum rate of chlorophyll a concentration was measured in the warm with minimum level measured in the cold months. The rate of chlorophyll a concentration showed an oligotrophic condition in the lake of karoon 4 dam. positive significant correlation were seen between the parameters of COD,NO3,temperature, pH, turbidity, chlorophyll a and phytoplankton abundance (P<0.01). The chlorophyll a concentration and phytoplankton community had a significant negative correlation with transparency (-P < 0.01). According to this research, 4 phyla of zooplankton was identified, include Rotifera, Protozoa, Cladocera and Copepoda. Overal 43 species were identified at four seasons. Most abundance was related to the phyla Rotifera (27 species), Copepoda (7 species), Cladocera (5 species) and Protozoa (4 species) respectively. The chlorophyll a concentration, amount of phosphate and zooplankton indicator spesies, showed an oligotrophic condition in the lake of karoon 4 dam. A positive significant correlation was seen between all groups of zooplanktons abundance and temperature, as well as chlorophyll a concentration. (P<0.01) , whereas, there was negative correlation whith no significant between DO and zooplankton communities (P>0.05).

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This study was carried out to seasonal determination of some morphological characteristics, Seasonal fecundity, Seasonal fluctuations of vertebrate-type steroids and seasonal analysis of gonadal histology in both female and male sexes of freshwater crayfish (Astacus leptodactylus Eschscholtz 1823) in the area of Aras dam Lake. Crayfish were collected respectively in June, August, November (2011) and January (2012). The average length and weight of male crayfish was higher than that of females. %GSI of females fluctuated within an extended range (between 0.6 and 13.5% from June to January). Both of synchronous and asynchronous ovaries were seen in August sampled ovaries; however asynchronous form was higher than another. The annual reproductive cycle of male A. leptodactylus was surveyed by study on the seasonal changes of the external appearance of the testes and vasa deferentia, fluctuations in the gonadosomatic index (GSI%) and the histological analysis of the male reproductive system. Based on the histological differentiation of testis, spermatogenisis devided to 5 separated stages. The findings suggested asynchronous testis in the species A.leptodactylus. The presence of primary spermatophore layer may help keeping spermatozoa alive while the secondary spermatophore layer may produces spermatophore or synthesize of acellular material which forms spermatophre. Pleopodal fecundity was 37.3%lower than ovarian fecundity observed. The significantly higher number of eggs attached to 3rd and 4th pairs of pleopods. The egg number and gonadosomatic index increased with female size while egg weight and egg diameter didn’t increase with female size. Hemolymph levels of 17β-estradiol and progesterone followed a similar fluctuation pattern with % GSI in females, while testosterone didn’t follow the mentioned pattern. The testis of November sampled crayfish presented significantly higher gonadosomatic (%GSI) index (P < 0.05).The most observed gonadosomaticindices were 13.5%(forfemales) and 1.21% (for males, in autumn. Althogh the lowest GSI was (0.50%) formales in spring and (0.26%0 for spent females in January. Testosterone which followed a similar pattern with %GSI in males increased remarkably in November. 17β-estradiol increased strictly in January. The strictly enhancement of the three estroid hormones in January in both male and female sexes could bedue totheir stimulating role in in spermatophre and egg lying in the mating season (In January). Most of the ovaries followed the asynchoronous growth pattern. Also the testes presented asynchoronous growth pattern in autumn.

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To investigate the effects of chronic morphine treatment and its cessation on thalamus and the somatosensory cortex, an ex vivo high resolution (500 MHz) H-1 nuclear magnetic resonance spectroscopy (NMRS), in the present study, was applied to detect multi

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Ex vivo H-1 NMR spectroscopy was used to measure changes in the concentrations of cerebral metabolites in the prefrontal cortex (PFC) and hippocampus of rats subjected to repeated morphine treatment known to cause tolerance/dependence. The results show th

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The central nervous system exhibits remarkable plasticity in early life. Prenatal morphine exposure may induce adverse behavioral effects on the neonate and the developing offspring. In the present study, we investigated the effect of prenatal morphine exposure (daily from embryonic days 12-16, 20 mg/kg) on 11-day-old chicks using two forms of spatial paradigms: one trial detour behavior task in which animals must bypass an obstacle to reach the desired goal without any training and detour learning task which required several trials of training to reach the detour criterion. The results showed that, on the condition that chicks could successfully detour in the first trial, morphine exposed chicks exhibited longer detour latency to finish the task, coupled by a preference for turning right versus turning left. In contrast, no significant difference in learning and memory was found in detour learning task between morphine exposed chicks and saline chicks. These findings suggest specific behavioral changes associated with prenatal exposure to opioids during mid to late gestation, also raise attention to the possible health hazard from pregnancy drug use in everyday life. (C) 2010 ISDN. Published by Elsevier Ltd. All rights reserved.

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Seasonal sampling from 40 immature Caspian salmon were performed in summer, autumn, winter and spring. The maximum ranges of RBC counts, Hct, Hb, WBC count and clotting times were observed in spring, summer, spring, spring and winter, respectively. The minimum amounts of these factors were counted in summer, winter, winter, winter and winter, respectively. Blood Samples were taken from healthy smolt, immature and adult Caspian salmon in spawning time. Hematological determinations and biochemical serum analysis were performed in 101 fish in the three samples. The ranges of hematological values for sample mean were counted. Red blood cell counts were 866600 mm3 and 1259400 mm3 in smolt and adult respectively. Hematocrit was 48.39% in smolt and 44.29% in adult. Hemoglobin was 8.85 gr/dl in smolt and 10.91 gr/dl in adult. White blood cell count was 8781.58 mm3 in smolt and 5217.55 mm3 in adult and mean were differential of WBC, Lymphocyte 90.57%in smolt and73.22% in adult. Neutrophil was 5.12% in smolt and 16.92% in adult, Monocyte were 1.27% in smolt and 4.24% in adult, Clotting time was 282.34 Seconds in smolt and 291.47 seconds in adult MCV, MCH and MCHC also meagered in smolt and adult. Biochemical parameter in immature and mature Caspian salmon meagered .Glucose concentration was 2.97 mmol.l- in immature and 1.99 mmol.l- in mature .Cholesterol concentration was 4.26 mmol.l- in immature and 7.06 mmol.l- in mature. Triglyceride amount was 2.35 mmol.l- in immature and 2.47 mmol.l- in mature and Calcium was 2.47 in immature and 2.61 mmol.l- in mature. An in situ study was made on erythrocytic isoantigens and hetero-antigen and their corresponding iso-and hetero-antibodies of sera by means of hemoagglutination tests on the blood sample, of 450 immature and 50 mature Caspian salmon. The absence of erythrocyte iso-antigens and hetero-antigen and their corresponding iso-and hetero-antibodies were shown by the experimental. It could be indicated an intra-specific variation and differences in species for kelardasht hatchery.

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The occurrence of diseases is a significant setback for successful aquafarming. One of the common fish bacterial disease syndromes, Edwardsiellosis is caused by Edwardsiella tarda, a gram-negative, rod shaped bacterium associated with several diseases of marine and fresh water fish. In this study, an attempt was made to observe and analyze the onset of clinical symptoms and certain haematological parameters in Koi Carp, Cyprinus carpio L., following artificial infection with Edwardsiella tarda. The disease progress was observed and the clinical symptoms were monitored over a period of 15 days following infection. Fish were sampled at three day intervals to analyse the haematological parameters: total erythrocyte counts (RBC), total leucocyte counts (WBC), haemoglobin content and differential leucocyte count. Clinical symptoms observed included: erratic swimming behaviour, loss of appetite, haemorrhages, dropsy and exophthalmia. There was a significant decrease in the total RBC and haemoglobin levels by the 3rd and 6th day post infection, and an increase thereafter. WBC counts were higher in all infected groups in comparison to the control group. A significant increase in the number of neutrophils was found in the infected group up to the 9th day and a decrease thereafter. The lymphocyte number was significantly less up to the 12th day while the monocyte counts were significantly higher up to the 12th day post infection. The results showed that the bacterium, E. tarda, is pathogenic to Koi Carp. The hematological changes and clinical signs in infected fish reported in this paper will be helpful in the identification and the control of this infection.

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The main aim of this research was to identify fatty acids composition of Caspian sea of White fish Rutilus frisi kutum tissue and their changes during one year cold storage (-18Ċ).The secondary aim was to determine the changes of moisture, ash, protein, fat, and to investigate the effects of storage time on peroxide, TBAi, FFA, and extractability of myofibrillar proteins of the fish tissue during one year cold storage (-18 Ċ). 10 samples of (Rutilus frisi kutum) were randomly collected from Anzali landings. The samples were frozen at -30 Ċ and kept in cold storage at -18Ċ for one year. According to time table, the samples were examined. The results showed that 27 fatty acids were identified. The unsaturated fatty acids (UFA) and saturated fatty acids (SFA) were 74/09 and 21/63 %, respectively, in fresh tissue. So that DHA (C22:6) oleic acid (C18:1c) had high amounts (15/07 ,20/57 ) among the UFA and palmitic acid (C16:0) was the most (13/09 %) among the SFA. The effects of freezing and cold storage on fish tissue showed that UFA and SFA contents have reached to 58/79 and 22/17 %, respectively, at the end of cold storage. It indicated that these compound change to each other during frozen storage. Also ω-3 and ω-6 series of fatty acids was 24/22 and 15/56% in fresh tissue, but their contents decreased to 8/68 and 5/11% at the end of period. Among the fatty acids C22:6, C18:1c and C16:0 had the most changes. The changes of fatty acids were significantly at 95% level expected for C18:0. Results showed that moisture, ash, protein, and fat contents were 75/9±0/03, 1/28±0/012, 21/8±0/2, and 4/1±0/01 % respectively, in fresh tissue. The moisture, ash, protein, and fat contents were 72/3±0/04, 1/83±0/05, 1/91±0/01 and 19/9±0/01 % respectively, at the end of storage period. Lipid damage was measured on the basis of free fatty acids (FFA), peroxide value (PV), and Thiobarbituric acid index (TBA-i). PV, TBARS and FFA concentration of frozen Caspian Sea white fish stored at -18 Ċ the temporal variation of these three variables were statistically significant (p<0.001). Results of White fish myofibrillar proteins showed aggregation of bound reduced for stored at 12 months. SDS-PAGE analysis revealed that, the intensity of the myosin heavy chain and actin bound was reduced with increasing storage time. SDS-PAGE patterns showed that myosin heavy chain was much more susceptible to hydrolysis than actin. Key words: Rutilus frisi kutum, frozen storage, ω-3, ω-6, protein myofibrillar