Biodegradation of Alkylbenzene Sulfonate in a Simulated Septic Tank and Drain Field

A straight-chain alkylben-zene sulfonate was 90 to 95 percent biologically degraded in a laboratory bench-scale septic tank and drain field. Under the same conditions, only about 35 percent of a highly branched alkylbenzene sulfonate was degraded.     

Acute Toxicity of Copper Sulfate and Chelated Copper to Channel Catfish Ictalurus punctatus

Channel catfish fingerlings Ictalurus punctatus were exposed to copper sulfate or a commercial chelated copper product in a series of static toxicity tests conducted using waters with a wide range of total alkalinity and hardness values. Estimates of mean 96 h LC50 values were 0.05, 0.73, 0.95, and 0.98 mg/L as Cu for copper sulfate and 0.06, 1.51, 1.97, and 1.74 mg/L as Cu for the chelated copper product in waters having total alkalinities of 16, 76, 127, and 240 mg/L CaCO₃ respectively. On a copper basis, the chelated product was significantly ( P < 0.05) less toxic to fish than copper sulfate in all waters except that of the lowest total alkalinity. Highly significant ( P < 0.01) linear relationships were found between LC50 values for copper from copper sulfate and pH, log [total alkalinity], and log [total hardness], of test waters. These results cast doubt on the validity of the formula commonly used to calculate practical copper sulfate pond treatment rates, which is based upon a simple linear relationship between application rate and total alkalinity.     

Tibial tuberosity advancement in 92 canine stifles: initial results,clinical outcome and owner evaluation

Objective To investigate the clinical outcomes, complications and owners' evaluation of the tibial tuberosity advancement (TTA) procedure in canine stifles. Methods A retrospective study of hospital records was performed to identify dogs diagnosed with partial or complete cranial cruciate ligament (CCL) rupture that had undergone TTA repair. Information obtained included signalment, period of lameness, surgical report, evidence of meniscal injury, postoperative recovery and peri-operative complications. Owners were asked to assess the long-term outcome. Results In a total of 72 dogs (median age, 6 years; median body weight, 34.8 kg), TTA was performed in 92 stifles. Twenty breeds were represented, with Labrador Retrievers and Rottweilers the most common. The period of lameness ranged from 3 days to 24 months. The median pre-operative lameness score was 3/4 and meniscal injury was present in 51 stifles. Minor complications occurred in 29% of cases. Major complications occurred in 6.5% of cases and consisted of meniscal injury and two tibial tuberosity fractures. All were successfully managed, with good limb function when subsequently assessed. In the owner evaluation, 96% reported moderate to great improvement postoperatively, with no lameness at rest and mild to no lameness after vigorous exercise. Conclusion Clinical outcome and owner evaluations in this case series indicate favourable results can be expected when CCL-deficient stifles are treated with TTA.     

Comparison of Copper Sulfate Concentrations to Control Ichthyophthiriasis in Fingerling Channel Catfish

ABSTRACT

Fingerling channel catfish Ictalurus punctatus were exposed to Ichthyophthirius multifiliis-infested fish until immature trophonts developed. The fish were transferred to individual static fiberglass tanks filled with 600 L of pond water (total alkalinity and total hardness was 220 mg/L and 101 mg/L, respectively) and were treated with 0, 1.1, 2.2, 3.3, or 4.4 mg/L copper sulfate (CuSO₄ · 5H₂O) every other day for four treatments to evaluate its effectiveness to control mortality associated with ichthyophthiriasis. Water temperature was maintained at 18 ± 1°C. Fish were observed for ten days post-treatment and mortalities were recorded. Results indicate that half of the recommended dose (1.1 mg/L CuSO₄) is needed to effectively control an occurrence of ichthyophthiriasis under the conditions of this study. However, fish culturists should be aware that effective CuSO₄ treatment of ichthyophthiriasis on channel catfish raised in ponds may be influenced by water chemistry characteristics and suspended materials such as pond sediments.     

Dietary copper effects survival of channel catfish challenged with Flavobacterium columnare

Columnaris disease is an important bacterial disease of commercially grown channel catfish, Ictalurus punctatus. Copper sulphate (CuSO₄) has been shown to be therapeutic and prophylactic as a water treatment for columnaris disease. Copper is an essential dietary component in animal feeds and CuSO₄ is typically included in base diets; a study was conducted to evaluate whether fish feed supplemented with additional CuSO₄ at 0, 40 and 80 mg kg^?1 of diet and fed at a daily rate of 3% body weight would affect survival to columnaris disease. Results indicate fish fed the copper‐supplemented diet for 2 weeks significantly increased survival following F. columnare challenge. This increase appeared to be dose‐dependent. The mean per cent survival (±SEM) for fish fed the base diet (unsupplemented) for 2 weeks and then challenged was 2.0% ± 1.1. Fish fed the base plus 40 mg CuSO₄ kg^?1 had a mean survival of 22.0% ± 11.0. Fish fed the base plus 80 mg CuSO₄ kg^?1 had a mean survival of 29.3% ± 13.4. The mean per cent survival for fish fed the base diet for 4 weeks and then challenged was 28.3% ± 9.0. Fish fed the base plus 40 mg CuSO₄ kg^?1 for 4 weeks had a mean survival of 12.5% ± 6.3. Fish fed the base plus 80 mg CuSO₄ kg^?1 for 4 weeks had a mean survival of 40.5% ± 8.1. There was a significant effect after 4 weeks with fish fed the base plus 80 mg CuSO₄ kg^?1 mg not with 40 mg kg^?1.     

Inter‐specific hybridization between Black Sea trout (Salmo labrax Pallas, 1814) and rainbow trout (Oncorhynchus mykiss Walbaum, 1792)

Thermal shock‐induced triploid and unshocked control hybrids between rainbow trout (Oncorhynchus mykiss) and Black Sea trout (Salmo labrax) and their parental species were produced under hatchery condition by using heat shocks. Triploidization reduced eyed egg rate and alevin yield in all groups. Low survival rate was observed in both shock‐induced triploid hybrid and non‐shock‐induced control hybrids. Although hybrids demonstrated low body weight during the first feeding stage, they reached higher body weight by day 200 when compared with Black Sea trout and rainbow trout. A higher specific growth rate was calculated as 3.60 in the triploid hybrid groups, 1.41 in the triploid Black Sea trout groups and 2.27 in the triploid rainbow trout groups between days 110 and 200. A lower condition factor was determined in the hybrid than in the diploid parental species. A negative value of mid‐parent heterosis (MPH) performance was deected for condition factor, and a favourable MPH was detected for specific growth rate and weight in hybrids.     

Evaluation of potassium permanganate against an experimental subacute infection of Flavobacterium columnare in channel catfish, Ictalurus punctatus (Rafinesque)

An experiment was performed to evaluate the efficacy of potassium permanganate (KMnO₄) as a prophylactic and therapeutic treatment of an experimental subacute infection of Flavobacterium columnare in channel catfish, Ictalurus punctatus . Fish were cutaneously abraded and divided into five treatment groups: (i) challenged by waterborne exposure to F. columnare and not treated with KMnO₄ (positive control), (ii) challenged and simultaneously treated with KMnO_4, (iii) challenged and treated with KMnO₄ at 1, 6 and 9 days post-challenge, (iv) not challenged and treated with KMnO₄ at 1, 6 and 9 days post-challenge (first negative control) and (v) not challenged and not treated (second negative control). The dosing of KMnO₄ was 2.0 mg L⁻¹ above the potassium permanganate demand for 2 h duration. The survival of the group challenged and simultaneously treated with KMnO₄ (99%) was significantly higher than the positive control (78%) and was not significantly different from the negative control groups. The challenged fish treated with KMnO₄ post-challenge had 7% higher survival than the positive control (85% compared with 78%), but that difference was not statistically significant. The results demonstrate that KMnO₄ has a clear prophylactic value but probably a marginal therapeutic value once the infection has established.     

Induction of Embryogenic Callus in Gossypium barbadense L. and Gossypium hirsutum L. by Hormone Treatments

The aim of this study was to induce embryogenic callus from various cultivars of cotton in tissue culture, so that a stable and efficient regeneration system could be developed to produce new cotton varieties for cultivation in Xinjiang. The explant materials were hypocotyls of the main cotton cultivars grown in Xinjiang, i. e. Xinhai 25, Xinhai 16, Xinluzao 39, and Xinluzao 42. We tested the effects of different combinations of two hormones (kinetin, KT; 2,4-dichlorophenoxyacetic acid, 2,4-D) on induction of callus from these explants. Calli were produced by the explants under four different combinations of hormones in the media. The optimal hormone combination to induce callus from Gossypium hirsutum explants was 0.1 mg·L^-1 KT + 0.05 mg·L^-1 2,4-D, while that to induce callus from Gossypium barbadense explants was 0.1 mg·L^-1 KT + 0.1 mg·L^-1 2,4-D. Hormone-free medium and medium containing double to the normal concentration of KNO₃ promoted the emergence of embryogenic callus. Filter paper placed under the medium promoted somatic embryo growth and regeneration of the root system. The differentiation and embryogenesis processes occurred more rapidly in G. hirsutum explants than those in G. barbadense explants. Using this protocol, normal plantlets of these cotton cultivars with strong roots were produced within 10 to 12 months. These methods could be used to increase the number of cotton genotypes that can be regenerated in tissue culture.