Identification of pathogenic Leptospira strains in tissues of a premature foal by use of polymerase chain reaction analysis.

Studies were carried out to determine the cause of death in a prematurely born Thoroughbred foal that died 24 hours after birth. Necropsy revealed gross lesions suggestive of septicemia. A commercial Leptospira polymerase chain reaction (PCR) assay designed to specifically amplify the hemolysis-associated protein 1 (hap1) gene present only in pathogenic Leptospira strains detected the presence of Leptospira DNA in various tissues of the foal. Histologic examination of lung, liver, kidney, and myocardium revealed numerous spirochetes in Warthin-Starry-stained tissue sections. Results of PCR analysis and histologic examination suggested a leptospiral infection in the newborn foal. At the moment of death, the infection coexisted with a streptococcal-associated aspiration bronchopneumonia and postpartum septicemia. These findings indicate that the PCR assay based on the amplification of the hap1 gene represents a useful tool for specific detection of pathogenic leptospira in field samples taken from horses.     

Multi-scale Modeling of Animal Movement and General Behavior Data Using Hidden Markov Models with Hierarchical Structures

Hidden Markov models (HMMs) are commonly used to model animal movement data and infer aspects of animal behavior. An HMM assumes that each data point from a time series of observations stems from one of N possible states. The states are loosely connected to behavioral modes that manifest themselves at the temporal resolution at which observations are made. Due to advances in tag technology and tracking with digital video recordings, data can be collected at increasingly fine temporal resolutions. Yet, inferences at time scales cruder than those at which data are collected and, which correspond to larger-scale behavioral processes, are not yet answered via HMMs. We include additional hierarchical structures to the basic HMM framework, incorporating multiple Markov chains at various time scales. The hierarchically structured HMMs allow for behavioral inferences at multiple time scales and can also serve as a means to avoid coarsening data. Our proposed framework is one of the first that models animal behavior simultaneously at multiple time scales, opening new possibilities in the area of animal movement and behavior modeling. We illustrate the application of hierarchically structured HMMs in two real-data examples: (i) vertical movements of harbor porpoises observed in the field, and (ii) garter snake movement data collected as part of an experimental design. Supplementary materials accompanying this paper appear online.     

Infection conditions for Neofabraea perennans and Phacidiopycnis washingtonensis on developing apple fruit in the orchard

European Journal of Plant Pathology - In Northern Germany, a major share of postharvest losses of apple fruit is due to preharvest infections by pathogenic fungi. Little is known about their...     

Schnelle und einfache Methode zum Nachweis der Fenhexamid-Resistenz bei Botrytis

Isolates of Botrytis cinerea collected from Northern German strawberry and raspberry farms were grouped into three categories according to their pattern of resistance against the fungicide fenhexamid. Strains with baseline sensitivity showed EC₅₀ values of 0.06–0.10 ppm (conidial germ-tube elongation) and 0.07–0.16 ppm (mycelial growth assay). For partially resistant isolates, the corresponding EC₅₀ values were similar for germ-tube elongation but higher (> 0.39 ppm) for mycelial growth. Highly resistant isolates produced more than 50% growth in both assays even at 200 ppm fenhexamid, the highest concentration tested. These isolates matched the criteria of resistance group Hyd R3. By means of a simple test consisting of the harvesting of conidia from sporulating field samples and their direct assay by germ-tube elongation, Hyd R3 resistance was identified within 24 h of sampling. If this assay is performed on overwintered samples prior to blossom time, site-specific recommendations about the use of fenhexamid can be made to the farmer during the running vegetation period.     

Betrachtung möglicher Auswirkungen des Klimawandels auf Schadpilze im Obstbau am Beispiel von Fruchtfäuleerregern an Äpfeln

Whereas the rise in temperature during the past 30–40 years has already had clear impacts on the phenology of fruit trees and pathogenic insects, there is a lack of such correlations for fungal pathogens. An examination of fruit rots indicates that pathogenic fungi react differentially to climate change due to their complex infection biology. The appearance of the black rot fungus Diplodia seriata in Northwestern Europe is best explained by rising temperatures during the vegetation period. An increase in fruit rot caused by Nectria galligena is anticipated when milder and more humid winter months favour canker formation on twigs and branches, thereby increasing inoculum for fruit infections. An increasing importance of Neofabraea alba and Glomerella cingulata and/or G.??acutata as storage rots of apples in Northern Germany cannot be safely correlated with the climate change at present. Research on fungi is currently being expanded at the OVB Jork in order to ensure a faster identification of new pathogens and a more thorough investigation of relevant features of their infection biology.     

A presumably exotic Phytophthora species causing dieback of Buxus sempervirens in Germany and Romania

Journal of Plant Diseases and Protection - Roots, collars and rhizosphere soils from diseased boxwood saplings (Buxus sempervirens) from German and Romanian nurseries were shown to be colonized by...     

Economic equilibrium in the Westland: An experimental analysis

The conditions prescribed in economic theory for “equilibrium” in an industry are “normal” earnings for those engaged. That best-known area of intensive horticulture, the Westland in South Holland, reached approximate economic equilibrium in 1971. Not all the constituent sectors of the industry were in mutual equilibrium, and to remain in overall equilibrium few additional resources will be permissible, although output must continue to increase relative to input.In the past such normal earnings are believed to have stimulated producers to further, unjustified expansion. Under current conditions Westland producers will be spared the consequences of unjustified response, because they will need to concentrate upon avoiding the trap of excess capacity. The purchasing power of their most important crop, tomatoes, being now seriously and progressively reduced, rationalization of production under glass is necessary and this is a difficult enough exercise in itself.