A new virus disease of watercress in England1

In 1983 plants showing symptoms typical of watercress chlorotic leafspot agent (WCLSA) were found in Kent (GB). Later, plants showing similar symptoms were found in Dorset (1986) and Hampshire (1987), the main watercress-producing regions of England. These plants, unlike those infected with WCLSA, contained virus particles which were isometric with diameters of 37-38 nm. An antiserum to the virus was produced, with a titre in immunodiffusion tests of 1/128 and this gave good results in immunosorbent electron microscopy (ISEM) and ELISA tests on crude plant sap. Purified preparations of the virus reacted positively in ISEM and immunodiffusion tests with an antiserum to watercress yellow spot virus, a partially described virus occurring in France. Tests suggest that the crook root fungus Spongospora subterranea f.sp. nasturtii is probably the vector of this virus but other means of transmission cannot be excluded. Virus incidence within watercress beds varied, with little or no infection in the water inlet region of the bed where there are also low levels of crook root infection, higher levels in the central region and highest levels at the outlet region where crook root infection is also highest.     

Parenteral Anticholinergics in Dogs With Normal and Elevated Intraocular Pressure

Dogs given parenteral anticholinergic drugs have been thought to be at risk for development or exacerbation of elevated intraocular pressure (IOP). In a randomized, blinded, placebo-controlled study, we evaluated the effect of intramuscular glycopyrrolate (0.01 mg/kg) on pupil diameter and IOP in unanesthetized normal dogs. Treatment with glycopyrrolate did not change pupil diameter or IOP from baseline, nor were there differences between glycopyrrolate and saline-treated (control) dogs. In addition, the authors retrospectively reviewed the medical records of 2,828 dogs undergoing general anesthesia between April 1987 and September 1990 to determine if there was an association between parenteral anticholinergic medication and postanesthetic elevation in IOP. The authors also determined the frequency of bradycardia requiring anticholinergic therapy during anesthesia in dogs with glaucoma. Of the 2,828 cases reviewed, the records of 46 dogs coded for glaucoma were examined in detail. The 46 dogs underwent 62 episodes of anesthesia, with 23 episodes including exposure to an anticholinergic drug. An increase in IOP from preanesthetic to postanesthetic measurement occurred in three dogs. One of these dogs received anticholinergic medication for bradycardia during anesthesia. The postanesthetic elevation in IOP in this dog was probably not drug related. Preanesthetic anticholinergic administration did not affect the incidence of anticholinergic administration for bradycardia during the anesthetic episode. Anticholinergic therapy during anesthesia was more frequent when the preanesthetic medication included an opiate drug. These studies do not indicate an association between parenteral anticholinergic administration and elevations in IOP.     

Reconciling poverty alleviation with reduction in fisheries capacity: boat aid in post-tsunami Aceh, Indonesia

Abstract  The tremendous loss of life and assets resulting from the 2004 tsunami dealt a devastating blow to the coastal communities of Aceh Province, Indonesia. An assessment of the fishing fleet structure pre- and post-tsunami, including associated pattern in boat aid, in 15 coastal communities was conducted and compared with data on boat relief efforts over 17 districts of the Province. Aid was found to be not proportionally allocated to losses incurred by communities and was in many cases below what could be seen as a trend toward overcapacity. The distribution of aid appeared to be done without consideration of the former structure of the fleet, which changed significantly over time (pre- and post-tsunami), and resulted in a new fleet of reduced diversity with a strong focus on the smaller boat categories. If this situation perpetuates after the initial post-disaster period, it may further exacerbate the pre-existing economic and geographic marginalisation of some remote communities, and reduce the capacities of the fleets to diversify and develop multi-species harvesting strategies; thus, increasing the risk of ecologically unsustainable exploitation in near shore areas.     

Is the effect of the NAO on North‐east Arctic cod,Gadus morhua,recruitment stock‐dependent?

There is considerable interest in understanding the effect of the North Atlantic Oscillation (NAO) on recruitment to North Atlantic cod stocks. An earlier analysis of data for the North‐east Arctic cod stock showed that, while there is an empirical relationship between recruitment and the NAO over the period 1973–96, this relationship was absent over the period 1946–72. It has recently been suggested that the effect of the NAO on recruitment depends on the size of the spawning stock. Here, the possibility that this explains the earlier result for North‐east Arctic cod is tested and rejected.     

Interference between triazine-resistant Brassica napus and Panicum miliaceum

Atrazine carryover often limits growers to production of atrazine-tolerant crops the year following application, and allows the increase of triazine-tolerant weed species such as Panicum miliaceum L. (wild proso millet). Tiriazine-resistant Brassica napus L. cv. ‘Triton’ (oilseed rape) was tested to characterize the nature of interspecific interference with P. miliaceum. In a greenhouse study, atrazine at 2.2 kg ha^?1 depressed oilseed rape fruit (siliqua) number and fruit dry weight, and delayed flowering, but did not significantly affect height or weight of shoots, Oilseed rape fruit weight was reduced at 200 P. miliaceum plants m^?2. fruit number and shoot weight were inhibited at 400 weeds m^?2. and height was reduced and flowering delayed at 600 weeds m^?2. Number and weight of fruits were reduced by one-third after 8 weeks of interference as compared to oilseed rape grown with the weed for 4 weeks. Oilseed rape height was reduced by 29% and shoot weight by 55% by 600 weeds m^?2 and 2–2 kg ha^?1 atrazine, while fruit number and weight were reduced by 72%. Oilseed rape shoot weight was reduced by 74% by 600 weeds m^?2 for 12 weeks of interference, while fruit number and weight were reduced by 85% and 82%. respectively. In a field study, fluazifop reduced early season P. miliaceum cover by 72%, but did not increase oilseed rape cover. Mid-season P. miliaceum shoot weight was decreased by 97% by fluazifop and oilseed rape shoot weight was increased by 34%. P. miliaceum control increased oilseed rape biomass by 38% at 89 days, but biomass of oilseed rape sown at 11.2 kg ha^?1 with 2.2 kg atrazine ha^?1 was not decreased by P. miliaceum interference at 89 days.     

Fate of fluroxypyr in water

Dissipation of fluroxypyr in North Dakota lake waters was examined in three laboratory studies: photolysis, aerobic metabolism, and anaerobic metabolism. Photolysis was negligible in sterilized water, with and without natural photosensitizers. In 1:10 sediment:water systems, 50% disappearance times of 0.5–2 weeks were observed in the metabolism studies (25°C). Major metabolites (>10%) included the dichloropyridinol and 3-chloropyridinol derivatives, while the 5-chloropyridinol derivative appeared (<7%) in anaerobic systems. The pyridinols disappeared readily in aerobic but more slowly in anaerobic systems. In typical pond and lake waters, fluroxypyr and pyridinols are expected to disappear by the end of the growing season. Devenir de fluroxypyr dans l'eau La dissipation du fluroxypyr dans les eaux de lac dans le Dakota Nord a étéétudiée dans 3 études de laboratoires: photolyse, métabolisme aérobique et métabolisme anaérobique. La photolyse était négligeable dans I'eau stérilisée, avec et sans photosensibilisants naturels. Dans des systémes sédiments/eau de 1/10 des temps de disparition 50% de 0-5-2 semaines ont été observées dans les études de meéabolisme (25°C). Les principaux metabolites (>10%) comprenaient les dérivés dichloropyridinol et 3-chloropyridinol, tandis que le dérivé 5-chloro-pyridinol apparaissait (<7%) dans les systemés anaérobiques. Les pyridinols disparaissent rapidement en aérobie mais lentement dans les systémes anaerobiques. Dans les eaux typiques de mares et d'étangs, le fluroxypyr et les pyridinols sont supposés avoir disparu à la fin de la saison de croissance. Verhalten von Fluroxypyr in Wasser Der Verlust an Rückständen von Fluroxypyr im Wasser aus Seen in North Dakota wurde hinsichtlich der Photolyse sowie des aeroben und anaeroben Metabolismus untersucht. Die Photolyse war in sterilisiertem Wasser mit und ohne natürlichen Photosensitizern vernachlässigbar. Bei den Metabolismusuntersuchungen bei 25°C in l:10-Sediment:Wasser-Systemen lagen die Zeiten für 50%igen Verlust bei 0,5.2 Wochen. Zu den Hauptmetaboliten (>10%) zählten Dichlorpyridinol und 3-Chlor-pyridinol-Derivate, während 5-Chlorpyridinol-Derivate in anaeroben Systemen unter 7% blieben. Die Pyridinole verschwanden rasch in aeroben, aber viel langsamer in anaerobischen Systemen. In solchen Gewässern werden Fluroxypyr und Pyridinole erwartungsgemäß zum Ende einer Vegetationsperiode verschwunden sein.     

Actions of sodium hypochlorite and hydrogen peroxide on seed dormancy and germination of wild oats, Avena fatua L.

Sodium hypochlorite (NaOCl) can release dormancy of imbibed wild oat (Avena fatua L.) seeds. Treatments found effective included (i) immersing intact seeds in 800 mm NaOCl for 1 h followed by incubation on 5 × 10^?4m gibberellin A₃(GA₃); (ii) immersing dehulled seeds in 800 mm NaOCl for 1 min followed by incubation on 5 × 10^?4m GA₃; (iii) immersion of dehulled seeds in much lower concentrations of NaOCl, e.g. 13 4 mm for 3 h followed by incubation on water; or (iv) incubating dehulled seeds on a low concentration of NaOCl. Based on the concentrations of each of the reagents required to produce equivalent responses, NaOCl is approximately 4–6 times more effective than hydrogen peroxide (H₂O₂) in triggering the onset of germination, and 6 times as effective in causing growth inhibition in the roots. These results suggest the modes of action of NaOCl and H₂O₂ in the termination of dormancy reside in a modification of the properties of the hull and seed coat membranes, and in the provision of additional oxygen to the seed.     

Malassezia dermatitis in the dog: a retrospective histopathological and immunopathological study of 86 cases (1990–95)

A retrospective histopathological and immunopathological study was conducted on 86 dogs with Malassezia dermatitis. West Highland White terriers, English Setters, Shih Tzus, Basset Hounds, American Cocker Spaniels, spayed females, and castrated males were found to be at increased risk. The histopathological reaction pattern of lymphocytic superficial perivascular to interstitial dermatitis with parakeratotic hyperkeratosis, irregular epidermal hyperplasia, diffuse intercellular oedema and lymphocytic exocytosis was found to be consistent with a diagnosis of Malassezia dermatitis whether yeast were histologically visible (73.3% of the cases) or not (26.7%). Immunopathological studies revealed that 60– > 90% of the inflammatory cells within the epidermis, and 25–75% of those within the dermis were CD3+T lymphocytes, and that the only immunoglobulin-positive cells were dermal plasma cells.     

Esophageal Replacement in the Dog by Microvascular Colon Transfer

An orthotopic colon graft based on the middle colic artery and vein was implanted with microvascular technique and a stapling instrument in five dogs. The grafts were successful in four dogs. A similar colon autograft was used to replace the entire thoracic esophagus in five dogs. The recipient vessels were the left carotid artery and left external jugular vein. Four of the grafts failed because of kinking and thrombosis of the arterial supply (2 dogs) or the venous outflow (2 dogs). One graft, which had a viable vascular supply, developed a severe leak at the colon-to-stomach anastomosis, and the dog was euthanatized on day 3. The recipient vascular pedicle was modified and used successfully to replace a portion of the cervical esophagus in three dogs. The grafts survived, the dogs could swallow liquids and semisolid food well, and, at necropsy after 4 weeks, the anastomotic sites were well healed. The graft sites contained essentially normal colon mucosa.