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Biomedical subjects

A Goodchild

Publications and source records attributed to A Goodchild.

4 recordsLinked to original sources

Introduction of bovine tuberculosis to north-east England by bought-in cattle.

The source of bovine tuberculosis was investigated in 31 herds in north-east England that experienced confirmed breakdowns between January 2002 and June 2004; nine of the herds had been restocked after the UK outbreak of foot-and-mouth disease in 2001. In all but one of the breakdowns the most likely source of infection was identified as one or more purchased animals. In 17 of the breakdowns, reactor animals were traced to herds from which the same combination of spoligotype and variable number tandem repeats was isolated, and in five breakdowns a different spoligotype was isolated. The most likely sources were located in Wales and the west and north of England, and included a Cheshire herd that was the most likely source of nine of the breakdowns. Three breakdowns were traced to Irish imports. Reactors in five of the breakdowns included homebred as well as purchased animals, providing evidence for the likely spread of the disease within the herds. The lack of geographical clustering of molecular types pointed to the overwhelming source of infection being cattle that had been bought-in.

Animals↗

QTLs for straw quality characteristics identified in recombinant inbred lines of a Hordeum vulgare x H. spontaneum cross in a Mediterranean environment.

Barley straw is commonly used as animal feed in many developing countries. Even a small increase in its nutritive value can have a large impact on animal production, and hence, on rural livelihood and human nutrition. Straw quality is strongly affected by environmental factors and is, therefore, difficult to improve with empirical breeding. The objective of this study was to identify molecular markers to facilitate the improvement of straw quality in barley. For this purpose, we have used the genetic linkage map that was already developed for recombinant inbred lines (RILs) of the cross between a Hordeum vulgare cultivar ('Arta') and a H. spontaneum line (H. spontaneum 41-1), covering a total of 890 cM. Straw parameters from RILs grown at Tel Hadya and Breda (ICARDA's research stations) in 2 years (1996/1997 and 1997/1998) were analyzed by NIRS for predicted nutritional characteristics including neutral detergent fiber, acid detergent fiber, lignin, digestible organic matter in dry matter, voluntary intake, crude protein, and straw morphology (the percentage of blades, sheaths, and stems). Localization of QTLs was performed using Windows QTL Cartographer, version 2.0. Seventy-three QTLs were identified, the majority of which (17) in the driest of the four environments. Only six QTLs were identified in two environments; in five cases, one of the two was the wettest environment. This is discussed in relation to the possibility of improving straw quality in favorable environments where yields are higher, rather than in dry environments where straw quality is already relatively good.

Animal Feed↗

The interferon-gamma field trial: background, principles and progress.

Since November 2002, the State Veterinary Service and the Veterinary Laboratories Agency have been conducting a field trial to assess the interferon-gamma test as an ancillary parallel test to the tuberculin skin test in herds with confirmed tuberculosis breakdowns. Here, Martin Vordermeier, Tony Goodchild, Richard Clifton-Hadley and Ricardo de la Rua describe the background to the trial, discuss the principle of the test and provide an update of progress so far

Animals↗

Life under nutrient limitation in oligotrophic marine environments: an eco/physiological perspective of Sphingopyxis alaskensis (formerly Sphingomonas alaskensis).

The oceans of the world are nutrient-limited environments that support a dynamic diversity of microbial life. Heterotrophic prokaryotes proliferate in oligotrophic regions and affect nutrient transformation and remineralization thereby impacting directly on the all marine biota. An important challenge in studying the microbial ecology of oligotrophic environments has been the isolation of ecologically important species. This goal has been recognized not only for its relevance in defining the dynamics of community composition, but for enabling physiological studies of competitive species and inferring their impact on the microbial food web. This review describes the successful isolation attempts of the ultramicrobacterium, Sphingopyxis alaskensis (formerly described as Sphingomonas alaskensis) using extinction dilution culturing methods. It then provides a comprehensive perspective of the unique physiological and genetic properties that have been identified that distinguish it from typical copiotrophic species. These properties are described through studies of the growth phase and growth rate control of macromolecular synthesis, stress resistance and global gene expression (proteomics). We also discuss the importance of integrating ecological and physiological approaches for studying microorganisms in marine environments.

Alaska↗