The intra‐ and intertester repeatability of radiographic elbow incongruity grading is high in chondrodystrophic dog breeds

Elbow incongruity is a form of elbow dysplasia that causes osteoarthritis, pain, and lameness, and it is common in chondrodystrophic dog breeds. The objective of this retrospective secondary analysis study was to evaluate the intra‐ and interobserver repeatability of a novel radiographic incongruity grading system for assessing elbow incongruity in three chondrodystrophic dog breeds—the dachshund, Skye Terrier, and Glen of Imaal Terrier. We conducted an observer agreement study that included 220 mediolateral antebrachial radiographs from 110 dogs with the elbow in 90° flexion. The radiographs were independently assessed by three observers at three time points, using a four‐stepped grading scale. The proportion of agreement and Kappa coefficient were calculated. Both the intra‐ and interobserver proportions of agreement were substantial when three grades were required to be identical (.705‐.777 and .609, respectively), and almost perfect for two identical grades (.991‐1.000 and .991, respectively). Some differences in repeatability between breeds were noted; specifically, the intraobserver repeatability was higher in the dachshund, and the interobserver repeatability was lower in the Glen of Imaal Terrier. Our study showed that the radiographic imaging protocol and incongruity grading system have high repeatability when assessing elbow incongruity in chondrodystrophic dog breeds.     

Influence of ammonium: Nitrate ratios on the growth and nitrogen uptake of pearl millet

Pearl millet [Pennisetum glaucum (L.) R. Br.] is a potentially high‐yielding grain crop for the Southern Coastal Plain region of the USA. Information on the growth and N nutrition of pearl millet is limited; therefore, this study was initiated with the objective of studying pearl millet growth, N content, N uptake patterns and N‐form preference. Plants were grown in solution culture using a modified Hoagland's solution. Solutions were changed weekly and transpirational losses replaced daily. The N‐form ratios were 1:0, 3:1, 1:1, 1:3 and 0:1 NH₄ ⁺ to NO₃ ^‐ Uptake was determined by difference between the initial and final solutions. Nitrate and NH₄ ⁺ uptake patterns were different from each other and were influenced by the ratio of NH₄ ⁺ to NO₃ ^‐. After the plants had been transferred to the solutions, ammonium was preferred for the first two weeks, with NO₃ ^‐ preferred thereafter. Nitrate uptake was highest during the grain filling period. Plant growth as measured by leaf, stem, root, and seed weight, plant height, average seed weight, and head length was generally reduced as NH₄ ⁺ increased. The largest reduction was observed between the 3:1 and 1:0 ratios. Ammonium nutrition had an overall negative effect on pearl millet growth. Ammonium fertilization of pearl millet under conditions that increase absorption of NH₄ ⁺ over NO₃ ^‐ may have a negative effect on pearl millet growth and development.     

Reaction toPhytophthora infestans of potato genotypes with race-specific resistance

Summary Phytophthora infestans isolates collected in Poland in 1987–1995 were evaluated on detached leaflets of a differential series consisting of potato genotypes possessing resistance genes R1–R11. On the same differentials was evaluated over three years a highly virulentP. infestans isolate MP 245. Isolate MP 245 and those from natural populations ofP. infestans were seldom or inconsistently pathogenic to R5, R8 and R9. When leaflets of the differentials were infected with MP 245 the lesions were often small and sporulation weak. A statistically significant interaction was found between years and pathogenicity of MP 245 to individual differentials. Attempts to train the isolate MP 245 for pathogenicity to R9 were unsuccessful. The variation in specific resistance of potato genotypes may complicate the evaluation of their resistance toP. infestans, as well as the evaluation of the virulence spectrum of natural fungus populations. This variation may be due to changes in specific pathogenicity of the fungus or in specific resistance of the potato. Some differentials have a possibly useful resistance toP. infestans.     

Fungi as potential factors limiting natural regeneration of pedunculate oak (Quercus robur) in mixed-species forest stands in Poland

Dieback of young Quercus robur seedlings can limit natural regeneration in mixed-species forest stands in Poland. The aim of this study was to examine the role of fungi in the dieback of oak seedlings in central Europe. Fungi were isolated from the stems and roots of Q. robur, from both healthy seedlings and seedlings with symptoms, that were sampled from four stands in Poland. In total, 111 distinct taxa were identified. Ascomycota was dominant, representing 95.6% of the isolates. Among the taxa identified, Alternaria alternata, Colletotrichum fioriniae, Colletotrichum godetiae, Coniella quercicola, Diaporthe eres, Gnomoniopsis paraclavulata, Ilyonectria rufa, Mucor genevensis, Penicillium glandicola, Tubakia dryina, and Umbelopsis changbaiensis were most frequently isolated, and were consistently found in stems and roots of both healthy and diseased plants. The community compositions of fungi in healthy and diseased stems were similar, although Fusarium species, especially Fusarium sp. 1 (FTSC 5) and F. sporotrichioides, were found mainly in seedlings with symptoms. The pathogenicity of the most consistently isolated species from stems and roots of diseased seedlings was tested on Q. robur seedlings. F. sporotrichioides caused the largest lesions on inoculated seedlings. Six weeks after inoculation, D. eres, C. fioriniae, G. paraclavulata, T. dryina, and F. sporotrichioides killed 0%–18.8% of seedlings, while I. rufa and Ilyonectria pseudodestructans did not cause any lesions or other symptoms. This study is the first comprehensive report suggesting that massive fungal attack can lead to oak seedling dieback in mixed-species forest stands in central Europe.     

Role of Blowing Agents in Expansion of High‐Amylose Starch Acetate During Extrusion

High‐amylose starch acetate (DS 2) was processed in a Brabender twin‐screw extruder with ethanol and isopropanol as blowing agents at concentrations of 0, 2, 5, 10, 15, and 25%. A constant temperature of 150°C, a constant screw speed of 140 rpm, and a die nozzle with diameter of 4.0 mm and length of 16.2 mm were used to study the role of blowing agents on the expansion of the extrudates. Extrudates without blowing agent shrunk considerably after exiting the die as the cells collapsed drastically after expansion. Stable radial expansion of the extrudates increased with increase in the ethanol concentration to an optimum value of 18.0 at 5% (db) ethanol concentration and decreased with further increase in the ethanol concentration. Stable radial expansion increased to a maximum of 17.0 as the concentration of isopropanol was increased to 25% (db), though the rate of increase in expansion decreased with the increase in isopropanol concentration >10%. Flashing off of blowing agents aided in removing the heat generated during extrusion. The faster the extrudate cooled, the less likely it was to shrink. SEM were used to observe the effects of concentration of blowing agents on cell morphology. Various phenomena involved during the expansion are discussed. To obtain an extrudate with high expansion and low density, isopropanol at 15–25% (db) was found most suitable in this study.     

Starch Acetate‐Maleate Mixed Ester Synthesis and Characterization

A new starch acetate‐maleate mixed ester with different degrees of substitution (DS) for each ester group was prepared. High‐amylose (70%) corn starch was first reacted at 123°C with ≈4.5 equivalents of acetic anhydride for different times, and then the intermediate products were further reacted at 80°C with 0.27–1.1 equivalents of maleic anhydride for a fixed time. ¹H NMR and alkaline saponification were used to determine DS values of acetyl and maleate groups. Increasing the reaction time from 60 to 120 min for starch and acetic anhydride increased DS of the acetyl group, while DS of the maleate group increased with increasing amounts of maleic anhydride. There was a good agreement between the two methods for DS determination. The reaction efficiency of acetylation increased from ≈30 to 50% with reaction time, and maleation decreased from ≈30 to 20% with increasing amounts of maleic anhydride. The mixed esters were characterized by ¹H NMR, ¹³C NMR, FTIR, DSC, and TGA. Characteristic peaks in ¹H NMR, ¹³C NMR, and FTIR spectra indicated the presence of acetyl and maleate groups in starch molecules. The exothermic peak in the DSC curve and the increase in thermal stability from the TGA curve were attributed to thermal cross‐linking of the double bond of the maleate group.     

Weathering and mobility sequence of minor elements on a basaltic pedomorphic surface,Galilee, Israel

A number of minor elements was determined in 21 samples of several soil profiles of a young pedomorphic surface on basalt, Upper Galilee, Israel, ranging from red basaltic Lithosols to lithic Red Mediterranean soils and montmorillonitic Grumusols (Xerorthents, Lithic Xerochrepts, and Chromoxererts).Strontium and to a lesser extent barium are lost during the weathering of the feldspars; Sr continues to be leached out on the slope. Titanium concentrates in the non-clay residue and follows iron during its redistribution on the slope. Manganese is more mobile than iron. Cobalt is partially correlated with manganese, but like Ni, Cr, Cu and V, these elements do not show any definite trend and appear to be rather immobile under the moderate weathering conditions of the Mediterranean environment where montmorillonite is the major clay mineral.     

Sialodacryoadenitis in the rat: effects of immunosuppression on the course of the disease

Eight-week-old outbred male and female Crl:CD(SD)BR rats were treated with prednisolone (PR) or cyclophosphamide (CY) and were inoculated intranasally with sialodacryoadenitis (SDA) virus. The course of the disease was compared with nonimmunosuppressed, SDA virus-inoculated rats of the same stock. Criteria used to compare SDA in the 3 groups, included histologic changes in salivary and lacrimal glands, immunofluorescent microscopy of paraffin-embedded tissues, serum amylase levels, and antibody response. Based on these criteria, there was little detectable difference in the course and intensity of SDA in PR-treated and nonimmunosuppressed rats. In CY-treated rats, there was a delay in the onset of SDA, in the appearance of inflammatory cells in affected glands, and in the reparative process in the salivary and lacrimal glands. Viral antigen persisted longer in CY-treated rats than in PR-treated and nonimmunosuppressed rats. Antibody to SDA virus was not detected in CY-treated rats. The efficacy of immunosuppression by PR and CY was confirmed by the sheep erythrocyte agglutination procedure performed in selected rats. Male and female rats of the same strain were immunosuppressed beginning 4 weeks after inoculation with SDA virus to produce recrudescence of the disease. Histologic examination of salivary and lacrimal glands, immunofluorescent microscopy, serum amylase values, and viral isolation studies did not reveal evidence of reactivation of a persistent viral infection or viral shedding. Based on these studies, there is no evidence that SDA virus may persist as an inapparent infection after recovery from the disease.     

Equine immunology 4: vaccines and antisera

This paper attempts to relate the practicalities of vaccine development to the ideals which should be aimed for in a new vaccine. The type of immune response induced is dependent upon the nature of the antigen in the vaccine and the site and timing of its presentation to the immune system. In this respect the influence of age, maternal immunity and antigenic competition are discussed. The possible side effects associated with vaccination are defined and vaccines which are currently available for horses are reviewed. These vaccines are mostly for the prevention of respiratory disease. Finally, the possible uses for antisera are considered.