The culture of striped mullet (Mugil cephalus Linnaeus) in ponds receiving heated effluent from a power plant

During 1972 and 1973, striped mullet (Mugil cephalus Linnaeus) were stocked into six ponds (located on the upper end of the Galveston Bay system, Texas, U.S.A.) receiving heated effluent. Fish were fed commercially prepared feeds. In 1972, mean daily weight and standard length gains in two ponds were 0.71 and 0.66 g and 0.65 and 0.59 mm. In 1973, mean daily weight and standard length gains in four ponds were 0.64, 0.36, 0.67, and 0.59 g and 1.03, 0.81, 0.71, and 0.67 mm. During the two year study, survival rates ranged from 50 to 85%; production, from 293 to 804 kg/ha. Food conversion fluctuated from 2.24 to 3.31; commercial feed costs, from $0.61 to $0.87 per kg of fish.     

Influence of temperature on growth and survival of juvenile winter flounder,Pseudopleuronectes americanus (Walbaum) reared under continuous light

Winter flounder, Pseudopleuronectes americanus, has emerged as a promising candidate flatfish for cold‐water aquaculture and restocking. Here, juveniles were reared for 8 weeks at three temperatures: 10, 15, and 20°C under 24‐hr light. All fish were imaged at stocking and at 2‐week intervals, where growth was measured as changes in standard length (S_L) and body area (B_A). By week 2, fish reared at 15 and 20°C were larger than those grown at 10°C. At weeks 4 to 6, fish at 15°C were larger than fish at 20°C. Linear regressions were used to model growth dynamics over time at each temperature. Highly significant linear growth trajectories were detected over time for S_L and B_A. S_L and B_A regressions also showed a significant difference among the slopes across temperatures, where comparing slopes showed the best temperature to rear the flounder was 15°C. Weights of fish held at 15°C and 20°C were greater than at 10°C at the termination of the experiment. Within each temperature, the growth rate of malpigmented fish was not different from that of the normally pigmented fish. Overall, growth of winter flounder was comparable to that of other commercially produced flatfish species, providing strong evidence for this flatfish species as a potential species for aquaculture.     

Climatic factors controlling the productivity of Norway spruce: A model-based analysis

The process-based growth model, BIOMASS, was modified to incorporate low-temperature effects on photosynthetic production in Norway spruce (Picea abies) stands growing in northern Sweden. The low-temperature features incorporated in BIOMASS made it possible to simulate and estimate the reduction in photosynthetic rates caused by boreal conditions. The following four simulation-scenarios were used: (i) ‘potential' photosynthesis without boreal restrictions; (ii) reduction caused by a frozen soil; (iii) reduction caused by incomplete recovery of photosynthetic capacity during spring as a result of damage caused by low winter temperatures; and (iv) reduction as an effect of frost-induced autumn decline. Annual photosynthetic production (or gross primary production (GPP)) was simulated for three calendar years, 1990–1992, for stands with low (control) and high (irrigated and fertilized) nutrient availability. The reduction of ‘potential' GPP, caused by the low-temperature effects, ranged from 35–44% for control (C) and from 34–42% for irrigated-fertilised (IL) stands, respectively. The most pronounced loss of ‘potential' GPP originated from reduced photosynthetic capacity, in spring and early summer, which led to losses of 21–28% for C and 19–26% for IL stands. The variation between years differed mainly as an effect of differences in spring temperatures, which resulted in different rates of recovery of photosynthetic capacity. Reductions caused by frozen soil and low photosynthetic capacity during winter were similar in C and IL stands (12–13%), as were the losses resulting from severe autumn frosts (3–4%). It is concluded that, unless the effects of frozen soils and reduced photosynthetic capacity during spring and early summer are considered, large errors (ca. 40%) will be introduced into estimates of the annual photosynthetic production of boreal conifer forests.     

Stereotactic body radiation therapy as an alternative to adrenalectomy for the treatment of pheochromocytomas in 8 dogs

The objective of this report is to describe the use and outcome of stereotactic body radiation therapy (SBRT) for treatment of pheochromocytomas in 8 dogs. Pheochromocytomas are an uncommon but challenging tumour to manage. Adrenalectomy is the standard of care for treatment of pheochromocytomas in both animals and humans; however, unpredictable catecholamine secretion from the tumour and vascular and local invasion of the tumour and thrombi can pose life-threatening perioperative and anaesthetic risks. SBRT has been investigated as an alternative to adrenalectomy in human patients with pheochromocytomas. Eight dogs with clinical signs, an adrenal mass, and cytology and/or urine normetanephrine/creatinine ratios consistent with pheochromocytoma were treated with SBRT in lieu of adrenalectomy. Three dogs presented with acute hemoabdomen. Seven dogs had caval tumour invasion, 3 with extension into the right atrium. Following SBRT, all dogs had complete resolution of clinical signs and reduced urine normetanephrine/creatinine ratio and/or tumour size. No significant anaesthetic complications were encountered. Acute radiation toxicity was limited to grade I gastrointestinal signs in 3 dogs and resolved within 1–2 days of symptomatic therapy. Five of 8 dogs were alive at the time of follow up, with a median follow up time of 25.8 months. SBRT resulted in a favourable outcome and mitigated the life-threatening risks of adrenalectomy in these 8 dogs. SBRT may be a safe and effective alternative to adrenalectomy for pheochromocytomas in dogs with non-resectable tumours, or for owners averse to the risks of surgery.     

Growth and dry-matter partitioning of young Populus trichocarpa in response to carbon dioxide concentration and mineral nutrient availability

Young individuals of a single black cottonwood (Populus trichocarpa Torr. & Gray) clone were raised for three growing seasons in whole-tree chambers and exposed to either ambient or elevated atmospheric carbon dioxide concentration ([CO2]), with either a high or a low mineral nutrient supply, in a factorial experimental design. Nutrient availability had a larger effect on growth and dry matter partitioning than did [CO2]. Total biomass did not differ significantly with CO2 treatment when nutrient availability was low. However, elevated [CO2] increased whole-plant biomass by 47% in the high nutrient availability treatment. Carbon dioxide enrichment reduced leaf area ratio and specific leaf area significantly, but had no significant effect on mean leaf size or leaf mass ratio. Root mass ratio was significantly increased by elevated [CO2] at low, but not at high nutrient availability. A modified "demographic harvesting approach" made possible the retrospective estimation of stem and branch dry masses for different years. The relative growth rates of stem and branch were significantly enhanced by elevated [CO2] with high, but not with low nutrient availability. Canopy productivity index (CPI), i.e., the amount of stem and branch wood produced annually per unit leaf area, was raised 12% by elevated [CO2] when nutrient availability was high, but was reduced when nutrient availability was low, because of increased below ground allocation.     

Immunomapping of desmosomal and nondesmosomal adhesion molecules in healthy canine footpad,haired skin and buccal mucosal epithelia: comparison with canine pemphigus foliaceus serum immunoglobulin G staining patterns

Pemphigus foliaceus (PF) is the most common canine autoimmune skin disease. In contrast to human PF (hPF), desmoglein‐1 is a minor autoantigen in the canine disease. The major autoantigen(s) of canine PF (cPF) remain(s) unknown, which limits the ability to perform mechanistic studies of lesion formation and the development of novel diagnostic and therapeutic strategies for this disease. The immunofluorescence patterns of selected desmosomal (desmoglein‐1, desmoglein‐3, desmocollin‐1, desmocollin‐3, desmoplakin‐1/2, plakoglobin and plakophilin‐1) and nondesmosomal adhesion proteins (E‐cadherin, claudin‐1, zona occludens‐1 and occludin) in healthy canine footpad, haired skin and buccal mucosal epithelia were determined using hPF and pemphigus vulgaris sera and specific antibodies. The immunostaining patterns were then compared with that of indirect immunofluorescence staining with 66 cPF sera. Most cPF sera (58 of 66; 88%) exhibited positive staining along keratinocyte margins in the stratum spinosum and stratum granulosum of canine footpad. One serum contained autoantibodies binding solely to stratum granulosum keratinocytes. Concurrent intercellular fluorescence in the stratum basale was limited to seven of 66 cPF sera (11%). Only 12 of 66 cPF sera (18%) also exhibited positive IF staining of the buccal mucosa. This study confirms the immunological heterogeneity of cPF immunoglobulin G autoantibodies. Moreover, the major indirect immunofluorescence staining pattern and the inability of most cPF sera to label the buccal mucosa closely matched that of desmocollin‐1. These observations warrant further investigation of desmocollin‐1 as a potential major cPF autoantigen.     

Congenital peritoneopericardial diaphragmatic hernia in an alpaca

An adult alpaca was presented because of abdominal pain and was diagnosed with an intestinal obstruction. The putative diagnosis at surgery was an intestinal obstruction caused by peritonitis and intra-abdominal adhesions. The cause of the inflammation was not determined at that time. The alpaca died soon after surgery from post-surgical complications and a peritoneopericardial diaphragmatic hernia that was not diagnosed until necropsy.