Acute Toxicity and Anesthetic Effects of Clove Oil in Penaeus semisulcatus under Various Water Quality Conditions

Acute toxicity and anesthetic effects of clove oil were studied in P. semisulcatus (1.8–2.1 g body weight). The EC₅₀ 1-h (the concentration effective for 50% of test animals), LC₅₀ 1-h (the concentration lethal to 50% of test animals after 1 h) and LC₅₀ 24-h (the concentration lethal to 50% of test animals after 24 h) were calculated at concentrations of 25, 130 and 30 mg/l, respectively, at 30°C, salinity 40 ppt, pH 8.6 and dissolved oxygen >6 mg/l. Generally, with increasing concentrations of clove oil, the times required for sedation and anesthesia decreased, while the recovery times increased. At concentrations 50, 100, 150 and 200 mg/l under temperature of 30°C and salinity of 40 ppt, the times required for sedation were 6 ± 0.2, 2.5 ± 0.3, 2 ± 0.08 and 0.5 ± 0.08 min, while times required for complete recovery were calculated to be 4.5 ± 0.3, 5.5 ± 0.17, 6.5 ± 0.25 and 11 ± 0.38 min, respectively. Also, the times required for deep anesthesia were 20 ± 1, 5 ± 0.5, 3 ± 0.4 and 2.2 ± 0.5 min in the above concentrations, while the times required for complete recovery were 10 ± 1, 11 ± 1.5, 14 ± 2.2 and 16 ± 3 min, respectively. Furthermore, considering the times to sedation, deep anesthesia and recovery at different temperatures of 20°C, 25°C, 30°C and 35°C and salinities of 25, 30, 35, 40 and 48 ppt; the combinations of salinity plus temperature and clove oil concentration plus salinity had the greatest and the least effects.     

Performance of juvenile Murray cod, Maccullochella peelii peelii (Mitchell), fed with diets of different protein to energy ratio

The results of a 56‐day experiment on juvenile Murray cod, Maccullochella peelii peelii, an Australian native fish with a high aquaculture potential, of mean weight 14.9 ± 0.04 g, fed with five experimental diets, one a series of 40% protein content and lipid levels of 10, 17 and 24% (P₄₀L₁₀, P₄₀L₁₇ and P₄₀L₂₄), and another of 50% protein and 17 and 24% (P₅₀L₁₇ and P₅₀L₂₄) lipid are presented. The specific growth rate (SGR) (% day^?1) of fish maintained on different diets ranged from 1.18 to 1.41, and was not significantly different between dietary treatments, except P₄₀L₁₀ and the rest. However, there was a general tendency for SGR to increase with increasing dietary lipid content at both protein levels. The food conversion ratio (FCR) for the 40% protein series diets were poorer compared with those of the 50% protein diets, and the best FCR of 1.14 was observed with the P₅₀L₁₇ diet. The protein efficiency ratio (PER), however, was better in fish reared on low protein diets. The net protein utilization (NPU) also did not differ significantly (P > 0.05) in relation to dietary treatment. As in the case of PER the highest NPU was observed in Murray cod reared on diet P₄₀L₂₄ and the lowest in fish fed with diet P₅₀L₂₄. The carcass lipid content reflected that of the diets, when significant increases in the lipid content was observed in relation to dietary lipid content at both protein levels. However, body muscle lipid content did not increase with increasing dietary lipid content, and was significantly lower than in the whole body. The fatty acids found in highest concentration amongst the saturates, monoenes and polyunsaturates (PUFAs) were 16 : 0, 18 : 1n‐9 and 22 : 6n‐3, respectively, and each of these accounted for more than 60% of each of the group's total. The muscle fatty acid content was affected by the dietary lipid content; for example the total amount (in μg mg^?1 lipid) of monoenes ranged from 72 ± 5.1 (P₄₀L₁₀) to 112 ± 10 (P₄₀L₂₄) and 112 ± 2.8 (P₅₀L₁₇) to 132 ± 11.8 (P₅₀L₂₄) and the n‐6 series fatty acids increased with increasing dietary lipid content, although not always significant. Most notably, 18 : 2n‐6 increased with the dietary lipid level in both series of diets.     

Retinal and lenticular lesions in vitamin-C-deficient juvenile red drum, Sciaenops ocellatus (L.)

Abstract Ocular pathologic findings in eyes of ascorbic acid-deficient juvenile red drum, Sciaenops ocellatus (L.), are described. Abnormalities in the most severely affected eyes included: reduced globe size and lack of normal globe rigidity; vascular congestion and intraocular haemorrhage; lenticular lesions which included disorganization of posterior cortex, vacuolation of posterior subcapsular cortex and posterior migration of lens epithelium; and severe central retinal degeneration. The authors suspect that retinal degeneration was related to phototoxic injury, to which these fish had increased susceptibility as a result of ascorbic acid deficiency. The cause for lenticular lesions was undetermined, but may have been related directly to ascorbic acid deficiency, indirectly to retinal degeneration, or both.     

Laboratory evaluation of a living attenuated vaccine against bluetongue type 20 virus

Living attenuated bluetongue Type 20 virus vaccine was tested in 9 to 12 month-old Australian Merino sheep, held in air conditioned, insect-free accommodation. The vaccine appeared avirulent and immunogenic and protected against infection with a second dose of homologous vaccine virus. No enhancement of virulence or significant change in immunogenicity was observed when the vaccine was passaged 3 times through sheep without antibody to bluetongue virus.     

Spatiotemporal variations of evapotranspiration and reference crop water requirement over 1957-2016 in Iran based on CRU TS gridded dataset

Agriculture needs to produce more food to feed the growing population in the 21^st century. It makes the reference crop water requirement (WREQ) a major challenge especially in regions with limited water and high water demand. Iran, with large climatic variability, is experiencing a serious water crisis due to limited water resources and inefficient agriculture. In order to overcome the issue of uneven distribution of weather stations, gridded Climatic Research Unit (CRU) data was applied to analyze the changes in potential evapotranspiration (PET), effective precipitation (EFFPRE) and WREQ. Validation of data using in situ observation showed an acceptable performance of CRU in Iran. Changes in PET, EFFPRE and WREQ were analyzed in two 30-a periods 1957-1986 and 1987-2016. Comparing two periods showed an increase in PET and WREQ in regions extended from the southwest to northeast and a decrease in the southeast, more significant in summer and spring. However, EFFPRE decreased in the southeast, northeast, and northwest, especially in winter and spring. Analysis of annual trends revealed an upward trend in PET (14.32 mm/decade) and WREQ (25.50 mm/decade), but a downward trend in EFFPRE (-11.8 mm/decade) over the second period. Changes in PET, EFFPRE and WREQ in winter have the impact on the annual trend. Among climate variables, WREQ showed a significant correlation (r=0.59) with minimum temperature. The increase in WREQ and decrease in EFFPRE would exacerbate the agricultural water crisis in Iran. With all changes in PET and WREQ, immediate actions are needed to address the challenges in agriculture and adapt to the changing climate.     

Ireland's Foreign‐Owned Technology Sector: Evolving Towards Sustainability?

ABSTRACT For some, Ireland's pursuit of an exogenous‐led development model has proved to be the cornerstone of recent economic success. Others point to recent high‐profile closures and argue that foreign‐owned operations are attracted to Ireland solely because of the advantageous tax breaks and lucrative grants scheme offered by the Irish government. We pay tribute to both arguments by pushing the level of enquiry beyond that of supply and backward linkages to try and gauge the actual performance of affiliates themselves. This brings some interesting facets of the Irish foreign direct investment scene to light. We highlight complexity of process, attainment of broader investment remits, and the emergence of a managerial class as integral to the ability of affiliates to adapt to and exploit organisational change. By examining 10 case studies and making use of media searches and company interviews, we highlight evidence of Ireland's largest technology transnational corporation affiliates showing positive performance advances. With these movements come, what we term, increased nodal significance of Irish operations within the global production network of their corporations. We argue against policy and theories that see these movements as linear and provide evidence of how some Irish operations have leveraged control and gained significant regional and global remits that have resulted in their growing significance, both in the corporation and in the country in which they are based. In the same line we argue that embeddedness in terms of supply linkages does not fit the Irish case and instead employ the term “network anchoring” of affiliates as they increase their nodal weighting through increased mandates.