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81.
Sea bream, Sparus aurata, is one of the most important fish species that is commonly cultured in the Mediterranean and the eastern coasts of the Atlantic Ocean. The life cycle of sea bream in its natural habitat passes through hyposaline and hypersaline lagoons. It is important to determine the tolerance of the fish to nitrogenous compounds for aquaculture at maximum stocking densities. In the present study, a series of acute experiments were performed to evaluate the effect of salinity on ammonia and nitrite toxicity to sea bream. The fish were exposed to different ammonia and nitrite concentrations according to the static renewal methodology at three different salinities (10, 20, and 30 ppt) and at a temperature of 20 C and a pH of 8.2. The toxic effect of total ammonia nitrogen (TAN) and nitrite nitrogen (NO2‐N) decreased with increasing salinity levels (P < 0.001). Acute toxicity (96‐h lethal concentration 50 [LC50]) values of TAN were determined to be 5.93, 11.72, and 19.38 mg/L at 10, 20, and 30 ppt salinity, respectively. The 96‐h LC50 values of NO2‐N were determined to be 370.80, 619.47, and 806.33 mg/L at 10, 20, and 30 ppt salinity, respectively. Results indicate that sea bream is less tolerant to ammonia but more tolerant to nitrite compared with some other fish species.  相似文献   
82.
Field experiments were carried out in the 2004 and 2005 growing seasons on drip irrigated dwarf green beans (Phaseolus vulgaris, humilis). Soil water content (SWC), spectral reflectance and yield were monitored. Based on these data crop evapotranspiration (ETc), soil water deficit index (SWDI), water use efficiency (WUE) and four separate spectral indexes were calculated. In order to determine use opportunities of spectral indexes for estimation of yield, SWDI and WUE, some statistical analyzes were made. Results showed that spectral indexes could be used for monitoring of yield, SWDI and WUE. Especially, Soil Adjusted Vegetation Index (SAVI) had the highest correlations with all three of the parameters. The estimation procedure which was given in this study has a potential use either during, or at the end of the growing season. Estimated values of WUE and SWDI were 3.2 (kg m?3) and 0.12, respectively, through SAVI and the given procedure, indicates the optimal water use and yield conditions for dwarf green beans. At this situation, probably ETc was 580 mm and yield was 25.5 t ha?1.  相似文献   
83.
Sixty white male mice were used in this study. Three groups, each comprising 20 mice were established. The control group (Group 1) was provided ad libitum pellet feed. On the other hand, the experimental groups, namely, Groups 2 and 3 were given pellet feed containing deltamethrin throughout the day, so that the animals were administered doses of 7.5 and 30 mg/kg/body weight/day, respectively. Blood samples were collected from all groups on the 15th, 30th, 45th, and 60th days of the experiment for measurement of serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), alcaline phosphatase (ALP), amylase and cholinesterase activities, and levels of glucose, urea, creatinine, triglyceride, cholesterol, calcium, phosphor, sodium, potassium, and chloride. According to data obtained, on the 15th day of the study, compared to the control group, statistically significant increase in urea, cholesterol, ALP, cholinesterase, calcium, and potassium levels/activities, and significant decrease in SGOT activity and chloride levels in Group 2, and significant increase in cholesterol, ALP, cholinesterase, calcium, potassium and chloride levels/activities in Group 3, and significant decrease in SGOT activity in Group 3 were determined. On the 30th day of the study, in comparison to the control group, triglyceride and cholesterol levels and ALP activity were determined to be significantly increased in the Group 2, whereas SGOT activity were significantly reduced in Group 2, and triglyceride and cholesterol levels were demonstrated to be significantly increased and SGOT activity was significantly reduced in Group 3. On the 45th day of the study, compared to the controls, significant increase in cholesterol and sodium levels, and significant decrease in triglyceride levels and ALP activity in Group 2, significant increase in creatinine, cholesterol and sodium levels and cholinesterase activity, and significant decrease in glucose, SGPT, ALP and phosphor levels/activities were detected in Group 3. On the 60th day, in other words, in the last period of the study, ALP activity, and triglyceride, calcium, and phosphor levels were determined to be significantly increased and significant decrease in amylase activity in Group 2. Furthermore, significant increase in triglyceride, ALP, amylase, calcium, phosphor, and potassium levels/activities, and significant decrease in glucose and creatinine levels were observed in Group 3. However no correlation was determined to exist between the changes were found to be statistically significant, and the administration dose and duration of deltamethrin in all periods and groups.  相似文献   
84.
This research was carried out to determine the effects of shearing of different genotypes of male lambs (one from pure Karayaka stock and two from its crossbreed) in winter on bodyweight gain, feed consumtion, feed conversion efficiency, rectal temperature and carcass yield. A total of 21 lambs aged 8 months were allocated randomly to experimental groups according to a 2 × 3 factorial arrangement for shorn and unshorn animals. The lambs were fed grass hay (100 g/lamb/day) and commercial concentrate feed ad libitum during a 54‐day of fattening period. The lambs were shorn in the middle of the experiment (27 days after beginning the trial). The interaction between the shearing treatment × genotype of the studied parameters was found to be insignificant. The shearing process increased the rectal temperature (P < 0.01), hot carcass yield (P < 0.05) and dressing percentage (P < 0.05) and decreased the weight of the edible inner organs (P < 0.01). Some of these parameters were affected by the genotypes. It was concluded that shearing male lambs in the winter can have a beneficial effect on the hot carcass weight and dressing percentage without affecting fattening performance, and the performance of Karayaka lambs and its crossbred male lambs were similar under the conditions of the present study.  相似文献   
85.
The severity of a transfusion reaction depends on alloantibody titres within the recipients' blood. Determination of an agglutination titre of naturally occurring alloantibody may help to assess the risk of transfusion reactions following an unmatched transfusion in a cat population. In this group of 312 cats 227 had blood type A, 78 had blood type B, and seven had type AB blood. All type B cats tested showed gross evidence of agglutinating anti-A antibody with plasma titres ranging from 2 to 256. Among the 227 type A domestic cats tested for plasma anti-B alloantibody titres, 70% had gross agglutination with titres ranging from 2 to 16, while 17.6% had microscopic agglutination. The remaining 12.4% of the type A cats were negative for both gross and microscopic agglutination. Based on agglutinating titres, the relative risk of a transfusion reaction when type A or AB blood was given to a type B cat was 6.4% with acute severe reaction, acute mild reactions in 85.9% and premature red cell destruction in 7.7%. On the other hand, transfusion of type AB blood or type B blood to type A cats carries a potential risk of acute mild transfusion reaction in 4.4% and premature red cell destruction in 83.3%. Transfusion of type A or B blood to type AB cats results in no apparent clinical transfusion reactions.  相似文献   
86.
Triploidy in fertilized eggs of Penaeus semisulcatus was induced by temperature and chemical shocks. The eggs, which were obtained from the shrimp broodstock maintained at 29 C, were exposed to cold temperature (8, 10, 12, and 14 C) and 6‐dimetiloaminopurine (6‐DMAP) concentrations (100, 150, 200, and 250 μM) for different durations (4, 6, and 8 min) 9 min after spawning was detected. While the highest triploidy rate of 49.7 ± 4.5% was obtained with a 200 μM 6‐DMAP concentration for a duration of 8 min, the best mean triploidy rate of 45.5 ± 2.8% for cold shock was obtained at a temperature of 10 C for a duration of 8 min. Temperature and 6‐DMAP concentration did not have significant effect on triploidy rate (P > 0.05) but shock duration had significant effect on triploidy rate for individual cold temperature shock or 6‐DMAP chemical shock (P < 0.05). Although longer durations of shock agent increased the rates of triploid induction, they generally had an adverse effect on hatching rates in the study.  相似文献   
87.
Journal of Pest Science - The larvae of Curculio elephas (Coleoptera: Curculionidae) and Polyphylla fullo (Coleoptera: Scarabaeidae) are major agricultural pests of chestnut and roots of cultivated...  相似文献   
88.
Transgenerational effects of environmental toxins require either a chromosomal or epigenetic alteration in the germ line. Transient exposure of a gestating female rat during the period of gonadal sex determination to the endocrine disruptors vinclozolin (an antiandrogenic compound) or methoxychlor (an estrogenic compound) induced an adult phenotype in the F1 generation of decreased spermatogenic capacity (cell number and viability) and increased incidence of male infertility. These effects were transferred through the male germ line to nearly all males of all subsequent generations examined (that is, F1 to F4). The effects on reproduction correlate with altered DNA methylation patterns in the germ line. The ability of an environmental factor (for example, endocrine disruptor) to reprogram the germ line and to promote a transgenerational disease state has significant implications for evolutionary biology and disease etiology.  相似文献   
89.
Amines and boranes are the archetypical Lewis bases and acids, respectively. The former can readily undergo one-electron oxidation to give radical cations, whereas the latter are easily reduced to afford radical anions. Here, we report the synthesis of a neutral tricoordinate boron derivative, which acts as a Lewis base and undergoes one-electron oxidation into the corresponding radical cation. These compounds can be regarded as the parent borylene (H-B:) and borinylium (H-B(+.)), respectively, stabilized by two cyclic (alkyl)(amino)carbenes. Ab initio calculations show that the highest occupied molecular orbital of the borane as well as the singly occupied molecular orbital of the radical cation are essentially a pair and a single electron, respectively, in the p(π) orbital of boron.  相似文献   
90.
A partial characterization of polyphenol oxidase (PPO) activity in Ocimum basilicum L. is described. PPO in O. basilicum L. was extracted and purified through (NH4)2SO4 precipitation, dialysis, and a Sepharose 4B-l-tyrosine-p-aminobenzoic acid affinity column. The samples obtained from (NH4)2SO4 precipitation and dialysis were used for the characterization of PPO. At the end of purification by affinity chromatography, 11.5-fold purification was achived. The purified enzyme exhibited a clear single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The molecular mass of the enzyme was estimated to be approximately 54 kDa. The contents of total phenolic and protein of O. basilicum L. extracts were determined. The total phenolic content of O. basilicum L. was determined spectrophotometrically according to the Folin-Ciocalteu procedure and was found to be 280 mg 100 g(-1) on a fresh weight basis. The protein content was determined according to the Bradford method. The enzyme showed activity to 4-methylcatechol, catechol, and pyrogallol substrates, but not to tyrosine. Therefore, of these three substrates, 4-methylcatecol was the best substrate due to the highest V(max)/K(m) value, followed by pyrogallol and catechol. The optimum pH was at 6, 8, and 9 for 4-methylcatechol, catechol, and pyrogallol, respectively. The enzyme had an optimum temperature of 20, 40, and 50 degrees C for 4-methylcatechol, catechol, and pyrogallol, respectively. It was found that optimum temperature and pH were dependent on the substrates studied. The enzyme activity with increasing temperature and inactivation time for 4-methylcatechol, catechol, and pyrogallol substrates decreased due to heat denaturation of the enzyme.  相似文献   
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