Influence of variable inundation regimes on soil collembola

Soil collembola in floodplain habitats are known to react dynamically to inundation, showing direct negative effects of inundation as well as rapid regeneration after flooding. Unknown, however, are how these communities react to variable inundation and the role that spatial and temporal habitat heterogeneity plays. Therefore, the small-scale spatio-temporal dynamics of soil collembolan communities after varying inundation were studied in floodplain habitats in the Upper Rhine Valley in Germany. After frequent flooding, significant differences in density and species richness were found between different floodplain levels of the same location. Due to different species’ responses, major differences occurred in community structure. After infrequent inundation the densities and species richness of the same sites and especially hygrophilous components decreased dramatically. Between neighbouring sites, species exchange occurred and community structures became more similar. The results show that at the same locality soil collembola react dynamically as well as differentially to changes in the hydrological regime. Small-scale landscape heterogeneity allows a mixture of differentially reacting species to occur within the same regional metacommunity. Long-term stability of collembolan communities despite the high spatio-temporal heterogeneity of floodplains is thus maintained by metacommunity dynamics.     

Applied aspects of neonicotinoid uses in crop protection

Neonicotinoid insecticides comprise seven commercially marketed active ingredients: imidacloprid, acetamiprid, nitenpyram, thiamethoxam, thiacloprid, clothianidin and dinotefuran. The technical profiles and main differences between neonicotinoid insecticides, including their spectrum of efficacy, are described: use for vector control, systemic properties and versatile application forms, especially seed treatment. New formulations have been developed to optimize the bioavailability of neonicotinoids through improved rain fastness, better retention and spreading of the spray deposit on the leaf surface, combined with higher leaf penetration. Combined formulations with pyrethroids and other insecticides are also being developed with the aim of broadening the insecticidal spectrum of neonicotinoids and to replace WHO Class I products from older chemical classes. These innovative developments for life-cycle management, jointly with the introduction of generic products, will, within the next few years, turn neonicotinoids into the most important chemical class in crop protection.     

Evaluation of risk factors associated with development of postoperative ileus in horses

OBJECTIVE: To determine factors associated with development of postoperative ileus (POI) in horses undergoing surgery for colic. DESIGN: Prospective case-control study. ANIMALS: 251 horses undergoing colic surgery, of which 47 developed POI. PROCEDURE: Signalment, history, clinicopathologic data, pre- and postoperative treatments, lesions, complications, costs, and outcome were recorded for all horses during hospitalization. RESULTS: Variables associated with increased odds of POI included small intestinal lesion, high PCV, and increased duration of anesthesia. There was modest evidence that pelvic flexure enterotomy and intraoperative administration of lidocaine may have reduced the odds of developing POI. CONCLUSIONS AND CLINICAL RELEVANCE: Findings during the preoperative and intraoperative periods can be used to identify horses at increased risk of POI. Reducing surgical and anesthetic duration should decrease the incidence of POI.     

欧洲饲料生产质量管理

食品安全是西欧消费者担心的主要问题,并且在世界各地得到越来越多的重视。饲料工业,包括其供应商,是食物链的一部分,因此必须对其产品的安全性负责。在这种情况下,可见和透明的质量保证措施就是“生产许可证”。H ACCP系统是用一个通过预料未来问题而提前采取行动来管理整个饲     

Cardiovascular involvement in 8 dogs with blastomyces dermatitidis infection

BACKGROUND: Blastomycosis is a common systemic fungal infection in dogs. HYPOTHESIS: Dogs with cardiovascular involvement may have abnormalities in electrical conduction and valvular function, and may have a worse prognosis. ANIMALS: Eight client-owned animals. METHODS: Dogs with cardiovascular lesions caused by blastomycosis were identified from retrospective evaluation of medical records. RESULTS: Five dogs had de novo infections and 3 had recurrences of previously treated infections. Harsh labored breathing, lethargy, and anorexia were the most common historic complaints. Three dogs had syncope. Physical examination and clinicopathologic data were typical of blastomycosis and included dyspnea, increased lung sounds, and lethargy. In addition, 3 dogs had heart murmurs and 1 had a third-degree atrioventricular block. Four dogs had myocarditis and 2 had pericarditis or epicarditis. Two dogs had cardiac signs attributed to extracardiac compression by fungal granulomas and clinical signs were relieved by treatment. Half of the remaining 6 dogs were euthanized; 2 of these were not treated. Of the remaining 3 dogs, 1 dog died acutely while sleeping; the second died intraoperatively during an attempt to place an epicardial pacemaker; and the third had Blastomyces-induced endocarditis and died of heart failure. CONCLUSIONS AND CLINICAL IMPORTANCE: Blastomycosis should be considered in the differential diagnosis of dogs from endemic areas with inflammatory myocarditis, heart block, heart base or intracardiac mass lesions, syncope, or endocarditis.     

In vitro propagation of canine distemper virus: establishment of persistent infection in Vero cells

Primary cultures of bovine fibroblast (BF) and canine brain cells, persistently infected with virulent R252-canine distemper virus (CDV), were cocultured with African green monkey (Vero) cells. Transfer of persistent CDV from BF to Vero cells varied inversely with the in vitro passage level (age) of the CDV-infected BF cells. Successful transfer of CDV to Vero cells was signaled by the transient appearance of viral syncytia, rapid spread of viral antigen to all Vero cells in the culture, and by recovery of cell-free Vero-infectious virus in culture fluids. With time, viral cytopathic effects in Vero cells containing CDV disappeared, and the infected lines could not be distinguished from noninfected control Vero cells, except by immunoassay for viral antigen.     

Clinical symptoms of and diagnostic possibilities for hypophyseal adenoma in horses

Hirsutism was the most often observed symptom in horses with a pituitary gland tumor and was present in all 13 examined horses. Other symptoms were atrophy of muscles (n = 10), hyperhidrosis (n = 8), polyuria/polydipsia (n = 5), bulging or supraorbital fat (n = 3), polyphagia (n = 2), apathy (n = 2) and seizures (n = 2). Laminitis was the most frequently observed concurrent disease (n = 8). Hyperglycaemia (mean, 9.9 +/- 3.71 mmol/l) in 13 horses and glucosuria (median, 55 [range, 2-55] mmol/l) in 7 horses were the most important laboratory results. The dexamethasone suppression test was positive in all tested horses (n = 9) 20 h after administration of dexamethasone. The pituitary gland tumor was visible in every case underwent computed tomography (n = 7). From these results it can be concluded that a pituitary gland tumor can be suspected based on typical clinical signs. Hyperglycaemia and glucosuria support the preliminary diagnosis and a positive dexamethasone suppression test allows a final diagnosis.     

Comparison of avoidance responses of an estuarine fish,Fundulus heteroclitus,and crustacean,Palaemonetes pugio,to bis (tri-n-butyltin) oxide

Avoidance responses of an estuarine fish, mummichog (Fundulus heteroclitus), and crustacean, grass shrimp (Palaemonetes pugio) to the antifoulant his (tri-n-butyltin) oxide (TBTO) were evaluated. Four out of six groups of mummichogs tested at 1.0 μg total organic Sn L^?1 showed avoidance. Total organic Sn concentrations of ≥ 3.7 μg L^?1 were avoided by this fish species in all cases. Higher concentrations of total organic Sn did not result in greater avoidance responses. Grass shrimp did not avoid total organic Sn concentrations between 2.3 and 30.0 μg L^?1. Response data at 2.3 and 30 μg L^?1 were similar. Mummichogs and grass shrimp differed greatly in their abilities to avoid potentially adverse concentrations of total organic Sn. Since mummichogs are major predators of grass shrimp, these behavioral responses may have important implications for tidal marsh ecosystems.     

Insecticidal natural products: new rocaglamide derivatives from Aglaia roxburghiana

An Erratum for this article has been published in Pest Management Science 56(5) 493 (2000). In the course of the screening for novel, naturally occurring pesticides from the plant family Meliaceae, an extract of the stem bark of Aglaia roxburghiana was found to exhibit significant insecticidal activity. In addition to rocaglamide, a known insecticide isolated from several species of the genus Aglaia, 15 new natural products were isolated from this plant. Isolation and structure elucidation of the natural products is described. The outstanding insecticidal activities of some of the compounds as well as a structure–activity relationship study are presented. © 1999 Society of Chemical Industry     

The Potential of Semiochemicals for Control of Phorodon humuli (Homoptera: Aphididae)

Field experiments employing yellow water-traps with vials releasing methyl salicylate, butyl isothiocyanate, 4-pentenyl isothiocyanate and diethyltoluamide were conducted during the spring migration of Phorodon humuli (Schrank), with the aim of identifying substances which might be used in the field to deter landing on hop plants. Methyl salicylate and the two isothiocyanates reduced trap catches of P. humuli. During the spring of 1994 a slow-release formulation of methyl salicylate and a β-acid-rich hop resin sprayed on to hop plants did not reduce aphid infestations significantly. In autumn cis,cis-nepetalactol, the main component of P. ‘humuli’s sex pheromone, prepared by various synthetic routes, increased trap catches of males and gynoparae equally. Catches of males in pheromone traps situated in a hop garden decreased with increasing trap height. Catches of males in traps charged with increasing doses of the cis,cis-nepetalactol peaked at 1 mg and then plateaued, whereas catches of gynoparae peaked similarly at 1 mg and then decreased. The effects of kairomones from an extract of the primary host, sex pheromone and a visual cue from yellow compared with clear water-traps were additive. The prospects for developing a semiochemicals-based control strategy against P. humuli, using some or all of the above elements, are discussed.