Serum biochemical and non-specific immune responses of rainbow trout (<Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>) to dietary nucleotide and chronic stress

The aim of the present study was to investigate whether supplementary nucleotide “Optimun” mitigates the adverse effects of chronic overcrowding in Oncorhynchus mykiss. Two experimental diets [control and nucleotide-supplemented (0.2 %)] and two rearing densities (10 and 30 kg m^?3) were combined to have four experimental treatments. The fish were reared for 45 days under different densities using different diets. At the end of the trial, FCR of the fish in higher density was significantly higher than those of the lower density. Nucleotide had no significant effects on growth performance and survival rate. Supplemented nucleotide significantly increased blood hematocrit, whereas it decreased serum total protein, total immunoglobulin (Ig) and creatinine. Overcrowding significantly increased serum glucose and total protein level and decreased serum lysozyme activity, but supplemented nucleotide produced no improvement in these items. No significant effect of overcrowding and dietary nucleotide was observed on serum cortisol. Supplemented nucleotide significantly increased serum urea under low stocking density. Overall, the results showed that 0.2 % “Optimun” had no positive effects on rainbow trout and also caused some immunological and metabolic problems. These findings are not in accordance with those obtained in the same species, with same nucleotide source and level, but acute stress; thus, further studies are encouraged on this topic.     

Application of nanosilver-coated zeolite as water filter media for fungal disinfection of rainbow trout (Oncorhynchus mykiss) eggs

This study investigated the indirect use of silver nanoparticles (AgNPs) for reduction of fungal infections during incubation period of fertilized rainbow trout eggs. Different concentrations of nanosilver-coated zeolite (0.5, 1, and 1.5 % AgNPs) were compared with unmodified zeolite as water filter media in semi-recirculation systems. For testing the effect of AgNPs on reduction of fungal infection, fertilized eggs were transferred in incubators receiving water from filters coated with nanosilver. The eggs in each incubator were inoculated with Saprolegnia-infected trout eggs. Any dead or infected eggs and embryos were periodically removed, while the performance of the filters was assessed by calculating the survival rates from fertilization up to completion of the yolk–sac absorption stage. The results showed that the filters containing 0.5 % AgNPs increased the survival rate by 4.56 % from fertilization to the swim up stage compared to the control (p < 0.05). Also, the additional application of activated carbon (as absorbent media) along with AgNP-coated media in filters caused an increase of about 11.24 % in the survival rate for the larval stage (p < 0.05). In contrast to the control group with about 6 % fungal infection, no infections were observed during the incubation period in the incubators containing nanosilver-coated filters. Therefore, the final results confirmed that the indirect use of AgNPs in the aforementioned filters were significantly effective for preventing fungal infections in semi-recirculation systems for rainbow trout, making them a candidate for replacing the chemical fungicides currently used during egg incubation in hatchery systems.     

Applications of polysaccharides (β-glucan) for physiological and biochemical parameters for evaluation rice tolerance under salinity stress at seedling stage

Salt stress is considered to be the most important abiotic stress and is the main problem in the interruption of the metabolic processes of plants, thereby limiting crop production. The present study was carried out to examine the effects of exogenously applied mushroom polysaccharides (β-glucan) on the growth of two rice varieties of Oryza sativa L. (MRQ74 and MR269) seedlings grown in vitro in 200 Mm sodium chloride (NaCl). Growth characteristics, including shoot and root height, and fresh and dry weight of salt-stressed rice seedlings were inhibited by sodium chloride treatment, the degree of which depends on the rice variety. The negative effects of salinity stress resulted in an imbalance of N, K⁺ Na⁺ and Na/K ratios and biochemical analysis activities a degradation of chlorophyll content in the plants. However, treatment with exogenously applied polysaccharides (β-glucan) ameliorated the stress generated by NaCl and improved the parameters mentioned above. The significance of the changes in growth and metabolism to salt stress tolerance in rice seedlings are discussed in the paper.     

Calcium and L-histidine interaction on nutrients accumulation in three tomato cultivars under nickel stress

This study was carried out to evaluation of some nutrients accumulation including Ni (nickel), Fe (iron), Mg (magnesium), Cu (copper), Ca (calcium) as well as Ni translocation factor (TF) in three tomato cultivars grown hydroponically under treatments including L-histidine (His) and calcium chloride (CaCl₂) (300 µM) exposed to nickel (II) sulfate (NiSO₄) (150 and 300 µM) by ICP-OES (inductively coupled plasma atomic emission spectroscopy) analysis. Tomato cultivars included Cal-J N3, Early Urbana Y and. Results indicated that shoot Ni accumulation increased under Ni stress. Ca and His reduced root, shoot Ni content and Ni TF (translocation factor) under Ni stress in Petoearly CH cultivar. Ni stress also decreased root and shoot Ca, Fe, Mg and Cu while Ca and His improved the nutrients uptake, and inhibited Ni accumulation. Therefore, Ca and His alleviated adverse effects of Ni stress on nutrients in Petoearly CH cultivar. Beside, Ca and His interaction alleviate Ni stress by inhibition of Ni uptake and translocation as well as plant nutrition improvement in the tomato plants.     

Axial pattern flap based on the lateral caudal arteries of the tail in the dog: an experimental study

OBJECTIVE: To determine applicability and size limits of an axial pattern flap based on the lateral caudal arteries in dogs to reconstruct caudodorsal trunk skin defects. STUDY DESIGN: Experimental study. ANIMALS: Ten mature, mixed breed dogs. METHODS: The lateral caudal vessels of the tail were incorporated in the flaps of the treatment group (n=5) and were ligated in the control group (n=5). Flaps were rotated and placed into experimentally created caudodorsal skin defects on the trunk. The length and area of tissue that remained viable in each flap were determined. RESULTS: Mean (+/-SD) survival area (222.8+/-32.9 cm2) and length (25.1+/-4.5 cm) of vascularized flaps were significantly greater (P<.05) compared with control flaps (94.9+/-13.4 cm2 and 14.61+/-4.7 cm). Necrosis occurred in all control flaps, resulting in lower percentage flap area (48.8%) and length (47.1%) survival compared with vascularized flaps (78.1%, 77.5%). CONCLUSIONS: Axial pattern flap based on lateral caudal arteries of the tail was successfully elevated and transferred in a single procedure, with 78% survival for closure of large experimentally created caudodorsal trunk defects in dogs. CLINICAL RELEVANCE: Large cutaneous defects of the caudodorsal trunk area in dog could be reconstructed with tail axial pattern flap. Limitations in terms of size and changes in animal appearance have to be considered before flap elevation.     

A feasibility study of using two-component polyurethane adhesive in constructing wooden structures

This investigation was conducted to determine the feasibility of using a two-component polyurethane （PUR） adhesive, with special waterproof properties, in constructing wooden structures. We designed and conducted tests to compare the shear strength and adhesion performance of PUR with polyvinyl acetate （PVAc） adhesive on block-shear specimens constructed of oriental beech （Fagus orientalis L.）, fir （Abies alba Mill.）, poplar （Populus deltoides Bartr.）, white oak （Quercus alba L.）, sycamore （Platanus orientalis L.） and white walnut （Juglans cinerea L.）. The values of the percentage of wood failure were also determined in specimens constructed with each adhesive. The highest shear strength values of both adhesives were obtained in specimens constructed of beech, while the lowest shear strength values were obtained in fir and poplar specimens. Average shear strength of the PUR adhesive was 16.5% higher than that of the PVAc adhesive. Specimens constructed of fir, poplar and sycamore were characterised by the highest percentages of wood failure, whereas the lowest average percentages of wood failure were obtained in beech and oak specimens. With the exception of oak specimens, there was no statistically significant difference between percentage of wood failure among the PUR and PVAc adhesives. Generally, the PUR adhesive showed an acceptable adhesion performance on wood materials used in our study.     

Combined effects of salinity and potassium concentration on juvenile mulloway (Argyrosomus japonicus, Temminck and Schlegel) in inland saline groundwater

This paper reports on experiments conducted to examine the combined effects of salinity and potassium concentration on survival and growth of juvenile mulloway (Argyrosomus japonicus, Temminck and Schlegel) in inland saline groundwater. Three separate experiments were conducted in 20 (±1)°C water. In the first experiment, mulloway were held in 60 L aquaria (triplicate) with salinities of 5, 15, 25 or 35 g L^?1 and potassium concentrations of 20%, 40%, 60% or 80% of the concentration present in oceanic water of the equivalent salinity in a 4 × 4 factorial combination for 7 days. Response surface contour diagrams were generated from survival data to estimate optimal conditions. The results showed that maximum survival of juvenile mulloway occurred at salinities of >14 g L^?1 and potassium concentrations of >38%. Survival was lowest at salinities of <7 and >33 g L^?1 and potassium concentrations of <25%. The second experiment was conducted with mulloway held in 60 L aquaria at salinities of 15, 25 or 35 g L^?1 and potassium concentrations of 40%, 60%, 80% or 100% in a 3 × 4 factorial combination for 44 days. Optimal conditions for maximum survival and growth of mulloway were within a salinity range of 15–35 g L^?1 and potassium concentration above 40%. The third experiment was conducted in three 500 L tanks to record the survival and growth of mulloway fingerlings held at 20 (±1)°C, 23 g L^?1 salinity and potassium concentrations of 50% for 8 months. Survival and growth of mulloway fingerling in inland saline groundwater were similar to those reported from a semi‐intensive floating tank system in inland saline water and sea cage trials in oceanic water.     

Factors and processes of gibbsite formation in Northern Thailand

Gibbsite is usually considered as end product of weathering in tropical environments with potentially high leaching rates. However, there are also hints towards gibbsite formation in initial stages of weathering in different climates. This study reports on a systematic approach based on soil forming factors in order to research the conditions of gibbsite formation in northern Thailand highlands. Therefore, three major study sites were chosen, which differ with respect to parent rock, relief, climate and vegetation. The results show that gibbsite is common in soils of the area. Reasons for its occurrence in soils are manifold. It can be a heritage of the parent rock, a result of initial weathering under free draining conditions or an accumulation under intense chemical weathering caused by high rainfall. Especially the investigation in granite and gneiss areas with a high share of primary minerals indicates that gibbsite can be an early and direct transformation without intermediates from micas and feldspars if free drainage is assured. With progressing soil genesis clay formation reduces drainage and favours kaolinite formation. Only sites with extremely high rainfall and low evaporation (high elevations in northern Thailand) show again a dominance of gibbsite in the clay fraction throughout the whole soil profile.