Evaluation of Mobility and Dissipation of Mefenoxam and Pendimethalin by Application of CSTR Model and Field Experiments Using Bare and Tobacco Tilled Soil Columns     

Vassilios Triantafyllidis  Dimitra Hela  Maria Papadaki  Dimitrios Bilalis  Ioannis Konstantinou 《Water, air, and soil pollution》2012,223(4):1625-1637

The soil mobility and dissipation of two pesticides with different physicochemical properties, namely mefenoxam, a systemic fungicide, and pendimethalin a selective herbicide, were determined in bare and tobacco tilled soil columns, which were installed in field conditions for over 125 days. Soil samples were collected at specific time intervals for a 125-day period and the rate of pesticide dissipation and leaching through the soil column was studied. The dissipation half-lives of mefenoxam from the top soil layer in tilled and bare soil columns were estimated at 10.3 and 13.1 days, respectively, while the corresponding half-lives for pendimethalin were 26.7 and 27.5 days, respectively. The dissipation of mefenoxam and pendimethalin from the top soil in tobacco cultivation was faster in comparison with bare soil; however, 120 days after their application, both pesticide residues were detected in the soil. Maximum concentrations of mefenoxam and pendimethalin were observed on the 15^th and 33^rd day, respectively, in the soil layer of 5–10 cm depth and on the 30^th day and 63^rd day, respectively, in the soil layer of 10–15 cm depth. Higher concentrations were observed in bare soil columns. The leaching of both pesticides was simulated with the continuous stirred tank reactor (CSTR) in series model. The simulated peak concentration and peak time for both pesticides fitted reasonably well to the experimental values.  相似文献   

Optimization and validation of the reversed-phase high-performance liquid chromatography with fluorescence detection method for the separation of tocopherol and tocotrienol isomers in cereals, employing a novel sorbent material     

Irakli MN  Samanidou VF  Papadoyannis IN 《Journal of agricultural and food chemistry》2012,60(9):2076-2082

The separation and determination of tocopherols (Ts) and tocotrienols (T3s) by reversed-phase high-performance liquid chromatography with fluorescence detection has been developed and validated after optimization of various chromatographic conditions and other experimental parameters. Analytes were separated on a PerfectSil Target ODS-3 (250 × 4.6 mm, 3 μm) column filled with a novel sorbent material of ultrapure silica gel. The separation of Ts and T3s was optimized in terms of mobile-phase composition and column temperature on the basis of the best compromise among efficiency, resolution, and analysis time. Using a gradient elution of mobile phase composed of isopropanol/water and 7 °C column temperature, a satisfactory resolution was achieved within 62 min. For the quantitative determination, α-T acetate (50 μg/mL) was used as the internal standard. Detection limits ranged from 0.27 μg/mL (γ-T) to 0.76 μg/mL (γ-T3). The validation of the method was examined performing intraday (n = 5) and interday (n = 3) assays and was found to be satisfactory, with high accuracy and precision results. Solid-phase extraction provided high relative extraction recoveries from cereal samples: 87.0% for γ-T3 and 115.5% for δ-T. The method was successfully applied to cereals, such as durum wheat, bread wheat, rice, barley, oat, rye, and corn.  相似文献   

The effect of soil salinity and pepino mosaic virus infection on the expression of tomato defence-related genes     

Nour Elhouda Zarrougui  Theodore Spanos  Christos Kissoudis  Ioannis C. Livieratos 《Plant pathology》2022,71(6):1304-1312

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Weaning of greater amberjack (<Emphasis Type="Italic">Seriola dumerilii</Emphasis> Risso 1810) juveniles from moist to dry pellet     

Ioannis E. Papadakis  Stavros Chatzifotis  Pascal Divanach  Maroudio Kentouri 《Aquaculture International》2008,16(1):13-25

The weaning of greater amberjack (Seriola dumerilii Risso 1810) to a dry diet was studied in two consecutive experiments. The experimental fish were hatchery-produced and grown to their initial size on a soft pellet containing 50% trash fish and 50% commercial dry pellet. In the first experiment, three homogenous groups of greater amberjacks (n = 153, mean weight: 374 ± 43 g), initially adapted for a period of 30 days to a diet with a 40% moisture content, were fed on commercial pellets containing three different levels of dietary moisture (7, 20 and 40%, respectively) for 126 days. We found that fish needed a month to adapt to the 7%- and 20%-moisture diets and that moisture content of the diet had a significant effect on fish growth in terms of increasing feed consumption and lowering feed conversion ratio. The group fed on the 20%-moisture diet not only compensated for the initial adaptation period but presented the higher growth rate and best feed conversion ratio. In the second experiment, all groups of experiment 1 were fed the same commercial diet with a 7% moisture content for 72 days. The group that had been previously fed on the 20%-moisture diet showed the best growth performance. The implication of the above results for the weaning of greater amberjack to dry diets is discussed in terms of the digestion process and physiology.  相似文献   

Morphological and free amino acid profile variability,as a tool for stock identification among farmed rainbow trout Oncorhynchus mykiss of different origin          下载免费PDF全文

Petros V Martsikalis  Menelaos Kavouras  Georgios A Gkafas  Apostolos P Apostolidis  Ioannis S Boziaris  Athanasios Exadactylos 《Aquaculture Research》2018,49(2):621-630

As a tool for stock identification the body morphology and the free amino acid (FAA) profile variability were determined among farmed rainbow trout Oncorhynchus mykiss (Walbaum 1792) from different geographical areas throughout Greece, using geometric morphometrics and Reversed Phase‐High‐Performance Liquid Chromatography. Significant intraspecific body shape variation was detected among the fish stocks of different origin. Canonical Variate Analysis distinguished populations into two groups being consistent to a great extent with a previous population genetics study. General linear models did not support an association of haplotypes and diet with shape. However, shape was significantly correlated with origin, water temperature, geological‐chemical‐climatic zones, histidine and arginine. Therefore, morphological variation was primarily driven by environmentally induced differences among these zones being the result of phenotypic plasticity. Environmental cues and rearing conditions played the pivotal role in comparison to broodstock origin. Specimens presented different FAA profiles depending on their geographical origin. Principal Component Analysis showed a division between eastern and western Greece which might be owed to the existence of climatic fluctuations affecting the abiotic factors. This combined approach offers an important tool for stock identification thus assisting environmental risk assessments in evaluation of potential ecological effects and fostering research excellence in sustainable aquaculture management.  相似文献   

Sea bream interactions toward the aquaculture net due to the presence of micro-fouling     

Alexios Glaropoulos  Vassilis M. Papadakis  Ioannis E. Papadakis  Antonia Georgara  Maroudio Kentouri 《Aquaculture International》2014,22(3):1203-1214

The technology of floating sea cages that is largely used in the Mediterranean aquaculture provides optimal conditions for the development of marine fouling. The present study investigates the influence of micro-fouling developed on a net, on sea bream behavior. Negative effects of biofouling were not tested since the study was performed under laboratory conditions and for short experimental period. The net condition (micro-fouling filaments) is further examined in comparison with a similar green–brown colored and a white net pen. From the results obtained, it can be concluded that micro-fouling filaments highly induce net biting. In contrast, the colored net tested in this study negatively affected sea bream interactions on the net. Results lead to the conclusion that the fouling filaments are more important to sea bream attraction than the net color, while both variables affect species behavior.  相似文献