Factors that may mediate the relationship between physical activity and the risk for developing knee osteoarthritis

Studies investigating the effect of physical activity on risk for developing osteoarthritis at weight-bearing joints have reported conflicting results. We examine evidence to suggest that this may be due to the existence of subgroups of individuals who differ in their response to physical activity, as well as methodological issues associated with the assessment of knee joint structure and physical activity. Recommendations for future studies of physical activity and the development of knee osteoarthritis are discussed.     

Geographic and topographic determinants of local FMD transmission applied to the 2001 UK FMD epidemic

Background

Models of Foot and Mouth Disease (FMD) transmission have assumed a homogeneous landscape across which Euclidean distance is a suitable measure of the spatial dependency of transmission. This paper investigated features of the landscape and their impact on transmission during the period of predominantly local spread which followed the implementation of the national movement ban during the 2001 UK FMD epidemic. In this study 113 farms diagnosed with FMD which had a known source of infection within 3 km (cases) were matched to 188 control farms which were either uninfected or infected at a later timepoint. Cases were matched to controls by Euclidean distance to the source of infection and farm size. Intervening geographical features and connectivity between the source of infection and case and controls were compared.

Results

Road distance between holdings, access to holdings, presence of forest, elevation change between holdings and the presence of intervening roads had no impact on the risk of local FMD transmission (p > 0.2). However the presence of linear features in the form of rivers and railways acted as barriers to FMD transmission (odds ratio = 0.507, 95% CIs = 0.297,0.887, p = 0.018).

Conclusion

This paper demonstrated that although FMD spread can generally be modelled using Euclidean distance and numbers of animals on susceptible holdings, the presence of rivers and railways has an additional protective effect reducing the probability of transmission between holdings.

     

The role of the social sciences and economics in understanding and informing tree biosecurity policy and planning: a global summary and synthesis

Increased global biosecurity threats to trees, woods and forests have been strongly linked to the upsurge in worldwide trade and the expansion of tourism. A whole range of social, economic and political actors are implicated and affected by the movement of pests and diseases along these international pathways. A number of factors affect the actions of stakeholders, and wider public, including their values and motivations, how risks are perceived and acted upon, their ability to act, as well as the existing regulatory and economic environment. Understanding these factors is key to any future attempts to improve biosecurity policy and practice, and we present available evidence on six key dimension: (1) the role of different stakeholders and the broader public within tree health; (2) levels of knowledge and awareness of tree pests and diseases amongst the variety of end-user ‘stakeholder’ groups, and influences on their attitudes and practices; (3) social acceptability of management approaches; (4) the impact of formal and informal governance arrangements; (5) risk communication; (6) economic analyses on the impact of tree pests. We conclude by identifying evidence gaps and emphasising the need for better integration within the social sciences and between the social and natural sciences to promote effective interdisciplinary and policy-relevant contributions to tree health.     

A bovine whole-genome radiation hybrid panel and outline map

A 3000-rad radiation hybrid panel was constructed for cattle and used to build outline RH maps for all 29 autosomes and the X and Y chromosomes. These outline maps contain about 1200 markers, most of which are anonymous microsatellite loci. Comparisons between the RH chromosome maps, other published RH maps, and linkage maps allow regions of chromosomes that are poorly mapped or that have sparse marker coverage to be identified. In some cases, mapping ambiguities can be resolved. The RH maps presented here are the starting point for mapping additional loci, in particular genes and ESTs that will allow detailed comparative maps between cattle and other species to be constructed. Radiation hybrid cell panels allow high-density genetic maps to be constructed, with the advantage over linkage mapping that markers do not need to be polymorphic. A large quantity of DNA has been prepared from the cells forming the RH panel reported here and is publicly available for mapping large numbers of loci.     

PEX13 is mutated in complementation group 13 of the peroxisome-biogenesis disorders.

The peroxisome-biogenesis disorders (PBDs) are a genetically and phenotypically diverse group of diseases caused by defects in peroxisome assembly. One of the milder clinical variants within the PBDs is neonatal adrenoleukodystrophy (NALD), a disease that is usually associated with partial defects in the import of peroxisomal matrix proteins that carry the type 1 or type 2 peroxisomal targeting signals. Here, we characterize the sole representative of complementation group 13 of the PBDs, a patient with NALD (patient PBD222). Skin fibroblasts from patient PBD222 display defects in the import of multiple peroxisomal matrix proteins. However, residual matrix-protein import can be detected in cells from patient PBD222, consistent with the relatively mild phenotypes of the patient. PEX13 encodes a peroxisomal membrane protein with a cytoplasmically exposed SH3 domain, and we find that expression of human PEX13 restores peroxisomal matrix-protein import in cells from patient PBD222. Furthermore, these cells are homozygous for a missense mutation at a conserved position in the PEX13 SH3 domain. This mutation attenuated the activity of human PEX13, and an analogous mutation in yeast PEX13 also reduced its activity. The mutation was absent in >100 control alleles, indicating that it is not a common polymorphism. Previous studies have demonstrated extragenic suppression in the PBDs, but the phenotypes of patient PBD222 cells could not be rescued by expression of any other human PEX genes. Taken together, these results provide strong evidence that mutations in PEX13 are responsible for disease in patient PBD222 and, by extension, in complementation group 13 of the PBDs.     

Rhinoviraemia

Rhinoviruses have been isolated from the serum of two infants at necropsy. Failure to isolate viruses from ten other sera from infants who yielded rhinoviruses from their respiratory tracts suggests that true rhinoviraemia occurs rarely, and is infrequently associated with rhinovirus infections, both clinical and subclinical, and death. It is suggested that this is the first report of isolations of human rhinoviruses from the blood.     

The proportion of genetic deviates in the tails of a normal population

Summary If genetic and environmental effects upon a quantitative phenotype X=G+E are normally and independently distributed then the probability distribution of genetic value G among individuals of fixed phenotypic value X is likewise a normal distribution. The mean of this a posteriori distribution of genetic values is +h ² (X− ) and the variance is σ _g ² (1−h ²), where is the a priori mean of X, h ² is the heritability ratio, and σ _g ² is genetic variance. For any fixed values of h ² and σ _g ² the a posteriori probability that the genetic value G associated with a given phenotype X exceeds the population mean by any specified amount can therefore be read directly from the tables of the standard normal distribution. The expected proportion of these superior genetic deviates among individuals whose phenotypic value exceeds some specified constant may also be calculated (by numerical analysis) and is presented here in graphical form. If phenotypic selection is practiced by choosing the best out of N phenotypes then N should be large enough to assure high probability of obtaining a superior genetic deviate. The operating characteristics of this type of selection are displayed in tabular form, again based upon numerical integration.

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Zusammenfassung Wenn genetische und umweltbedingte Effekte auf einen quantitativen Ph?notyp X=G+E von einander unabh?ngig und normal verteilt sind, dann entspricht die Wahrscheinlichkeitsverteilung des genetischen Werts G unter Individuen mit fixiertem ph?notypischem Wert X gleichfalls einer Normalverteilung. Das Mittel dieser a posteriori-Verteilung der genetischen Werte ist +h ² (X− ) und die Varianz ist σ _g ² (1−h ²); wobei das a priori-Mittel von X, h ² der Heritabilit?tskoeffizient und σ _g ² die genetische Varianz sind. Für jeden fixierten Wert von h ² und σ _g ² kann daher die a posteriori-Wahrscheinlichkeit, da? der genetische Wert G das Populationsmittel in Verbindung mit einem gegebenen Ph?notyp X um einen bestimmten Wert übersteigt, direkt aus den Tabellen einer standardisierten Normalverteilung abgelesen werden. Der erwartete Anteil dieser überlegenen, genetisch bedingten Abweichung unter Individuen, deren ph?notypischer Wert einen vorgegebenen Konstantwert übersteigt, kann ebenfalls numerisch errechnet werden. Er wird im vorliegenden Fall graphisch dargestellt. Wenn eine ph?notypische Selektion zur Auswahl der besten Ph?notypen aus N Individuen erfolgt, sollte N gro? genug sein, um mit hoher Wahrscheinlichkeit eine überlegene, genetisch bedingte Abweichung zu erhalten. Die wirksamen Charakteristiken dieses Typs der Selektion werden in tabellierter Form wiedergegeben, die gleichfalls auf numerischer Integration beruht.

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Dedicated to Dr. George F. Sprague on the occasion of his 65^th birthday.

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Cooperative investigations of the Colorado Agricultural Experiment Station, the Crops Research Division, Agricultural Research Service, U.S. Department of Agriculture, and the Beet Sugar Development Foundation. Approved by the Colorado Agricultural Experiment Station for publication as Scientific Series Article No. 880. Paper No. BU-78, Biometrics Unit, and Paper No. 529, Plant Breeding Department, Cornell University.

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Geneticist, Crops Research Division, Agricultural Research Service, U.S. Department of Agriculture; now deceased.

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Formerly Research Assistant, Colorado State University; now Assistant Professor of Biological Statistics, Cornell University.     

Cloning, localization, and permanent expression of a Drosophila octopamine receptor

A cDNA for a member of the G protein-coupled receptor family was isolated from Drosophila using a probe derived from a human beta 2-adrenergic receptor cDNA. This Drosophila receptor gene is localized at 99A10-B1 on the right arm of chromosome 3 and is preferentially expressed in Drosophila heads. The insect octopamine receptor has been permanently expressed in mammalian cells, where it mediates the attenuation of adenylate cyclase activity and exhibits a pharmacological profile consistent with an octopamine type 1 receptor. Sequence and pharmacological comparisons indicate that the octopamine receptor is unique but closely related to mammalian adrenergic receptors, perhaps as an evolutionary precursor.