Response to a standardized psychogenic stressor as an indicator of welfare status     

Nicola J. Rooney  Samantha A. Gaines  Hamish D.C. Denham  John W.S. Bradshaw 《Journal of Veterinary Behavior: Clinical Applications and Research》2009,4(2):77-78

  相似文献   

Influence of owners’ Attentional focus on the response of their dogs,canis familiaris     

Barbara Schöning  John W.S. Bradshaw 《Journal of Veterinary Behavior: Clinical Applications and Research》2009,4(2):95-96

  相似文献   

A novel secondary metabolite from the Eucalyptus pathogen Mycosphaerella cryptica     

G. Assante  G. Nasini  S. Zhang  R. E. Bradshaw 《Forest Pathology》2009,39(5):289-292

The most abundant metabolite of the eucalyptus leaf spot pathogen Mycosphaerella cryptica was extracted from agar cultures. The structure of the compound was elucidated by detailed studies of NMR and MS data and by comparison with derivatives. The compound is a previously undescribed diphenylether structurally related to pannaric acid found in lichens. Culture extracts from another species of Mycosphaerella isolated from the same environment yielded 5‐hydroxymethylfuran‐3‐carboxylic acid, a furan acidic compound previously isolated from a basidiomycete fungus. Assays for bioactivity of these metabolites revealed no evidence for antimicrobial activity. Some phytotoxicity was seen on newly emerged leaves of Eucalyptus globulus, but not on juvenile or adult leaves, when treated with either metabolite.  相似文献   

Relative importance of seed‐tuber and soilborne inoculum in causing black dot disease of potato     

A. K. Lees  J. L. Brierley  J. A. Stewart  A. J. Hilton  S. J. Wale  P. Gladders  N. J. Bradshaw  J. C. Peters 《Plant pathology》2010,59(4):693-702

Controlled‐environment and field experiments were done to quantify the individual contribution of seed‐tuber and soilborne inoculum of Colletotrichum coccodes in causing black dot disease of potato tubers. Seed‐tuber and soilborne inocula of C. coccodes were quantified using an existing real‐time PCR assay and related to subsequent incidence and severity of disease. In four field trials, a controlled‐environment experiment and through the monitoring of 122 commercial crops, seed‐tuber inoculum was found to be relatively less important than soilborne inoculum in causing black dot, and the level of seed‐tuber inoculum did not significantly affect either the incidence or severity of disease or the percentage of progeny tubers deemed unmarketable. By contrast, soilborne inoculum had the potential to result in high levels of disease and the level of C. coccodes soil infestation (pg DNA g^?1 soil) was found to have a significant effect. At soil infestation levels below 100 pg DNA C. coccodes g^?1 soil, 7% of commercial crops had an incidence of black dot greater than 20%, increasing to 40% and 57% of crops at levels of 100–1000 pg g^?1 and >1000 pg g^?1 soil, respectively. These arbitrary threshold levels for soilborne inoculum related to disease risk are discussed. Interpretation of disease risk based on inoculum levels must, in the future, be informed by agronomic variables and potential control strategies.  相似文献   

Factors influencing the Holocene history of Fagus     

R.H.W. Bradshaw  N. Kito  T. Giesecke 《Forest Ecology and Management》2010

The Holocene histories of three species of Fagus with related autecologies (F. sylvatica, F. grandifolia and F. crenata) are reviewed to compare factors that have affected the long-term dynamics of the species distributions. There are similar climatic controls exerted on all three species and their spreading histories were strongly influenced by the location of glacial refugia and the apparent establishment of outlying founder populations early in the Holocene. Under ideal growth conditions all three species showed similar population doubling rates, with estimated spreading rates of less than 100 m per year. Stand-scale disturbance is shown to have facilitated the spread of F. sylvatica at its northern distribution limits.  相似文献   

Strange bedfellows? Techno-fixes to solve the big conservation issues in southern Asia     

Barry W. Brook  Corey J.A. Bradshaw 《Biological conservation》2012,151(1):7-10

The conservation challenges facing mega-biodiverse South and Southeast Asia in the 21st century are enormous. For millennia, much of the habitat of these regions was only lightly modified by human endeavour, yet now it is experiencing rampant deforestation, logging, biofuel cropping, invasive species expansion, and the synergies of climate change, drought, fire and sea-level rise. Although small-scale conservation management might assist some species and habitats, the broader sweep of problems requires big thinking and some radical solutions. Given the long expected lead times between progressive economic development and stabilization of human population size and consumption rates, we argue that ‘technological fixes’ cannot be ignored if we are to address social and fiscal drivers of environmental degradation and associated species extinctions in rapidly developing regions like southern Asia. The pursuit of cheap and abundant ‘clean’ energy from an economically rational mix of nuclear power, geothermal, solar, wind, and hydrogen-derivative ‘synfuels’, is fundamental to this goal. This will permit pathways of high-tech economic development that include intensified (high energy-input) agriculture over small land areas, full recycling of material goods, a transition from fossil-fuel use for transport and electricity generation, a rejection of tropical biofuels that require vast areas of arable land for production, and a viable alternative to the damming of major waterways like the Mekong, Murum and northern tributaries of the Ganges and Brahmaputra Rivers for hydroelectricity. Rational approaches that work at large scales must be used to deal with the ultimate, rather than just proximate, drivers of biodiversity loss in the rapidly developing regions of southern Asia.  相似文献   

Complex interplay between intrinsic and extrinsic drivers of long-term survival trends in southern elephant seals     

Siobhan C de Little  Corey JA Bradshaw  Clive R McMahon  Mark A Hindell 《BMC ecology》2007,7(1):3

Background  

Determining the relative contribution of intrinsic and extrinsic factors to fluctuations in population size, trends and demographic composition is analytically complex. It is often only possible to examine the combined effects of these factors through measurements made over long periods, spanning an array of population densities or levels of food availability. Using age-structured mark-recapture models and datasets spanning five decades (1950–1999), and two periods of differing relative population density, we estimated age-specific probabilities of survival and examined the combined effects of population density and environmental conditions on juvenile survival of southern elephant seals at Macquarie Island.  相似文献   

Evidence that resistance to potato leafroll virus accumulation in tetraploidsolarium tuberosum L. is controlled by one or few major genes that are not complementary     

Ruth M. Solomon-Blackburn  Hugh Barker  John E. Bradshaw  Walter De Jong 《Potato Research》2003,46(3-4):137-145

Summary Previous investigations into the inheritance of resistance to accumulation of potato leafroll virus indicated a dominant major-gene effect, but the segregation ratios in progenies of crosses were a closer fit to a model involving two complementary genes (both required for resistance and one present in the susceptible parent cultivar, Maris Piper) than to a single gene model. In this study, we tested the complementary gene hypothesis by backcrossing susceptible segregants from one of these progenies to their susceptible parent, Maris Piper. No resistant segregants were found in the five backcross progenies examined, so the complementary gene hypothesis was not supported. There was significant variation between susceptible progeny-members in these backcrosses. The progeny of another, highly resistant parent clone, G. 8107(1), selfed, was also examined: all members were resistant. Whilst there is evidently a dominant major-gene effect involved, this is not the whole picture and there are other unidentified genetic effects.  相似文献   

Assessing general combining ability for gangrene resistance by means of a glasshouse seedling test   总被引：3，自引：0，他引：3  

J. E. Bradshaw  R. L. Wastie  Helen E. Stewart 《Potato Research》1996,39(1):179-183

Summary A seedling progeny test for resistance to gangrene (Phoma foveata) was used to evaluate progenies from a 15×15 half diallel set of crosses, including 14 selfs and 25 reciprocal crosses, which was originally made to investigate the inheritance of resistance to late blight and cyst nematodes. Nine out of the 14 selfs were more susceptible than the crosses involving their parents, so that overall the selfs were slightly more susceptible than the crosses, thus providing evidence of non-additive gene action in favour of resistance. However, when the selfs were omitted from the analysis, all of the variation between progenies could be attributed to differences in the General Combining Abilities (GCAs) of their parents. The four parents with the best GCAs for gangrene resistance all had sizeable contributions fromSolanum tuberosum subsp.andigena in their pedigrees.  相似文献   

Assessing progenies of potato for resistance to skin spot (Polyscytalum pustulans) in the glasshouse     

R. L. Wastie  Helen E. Stewart  J. E. Bradshaw  Alison K. Lees 《Potato Research》1997,40(4):383-389

Summary Crosses were made between six parents differing in susceptibility to skin spot and glasshouse-grown tubers from true seedlings of the nine resulting progenies assessed for resistance to the disease. The assessment was evaluated by a two-year comparison with the behaviour of field-grown tubers of the progenies and their parents. The correlations between progenies in the glasshouse and field were r=0.911 and 0.753 and those between the mid-parental values and the progeny means were high (r>0.864), indicating that parental differences were heritable. It is concluded that correlations were sufficient for glasshouse-grown tubers to be used for assessing large numbers of progenies in genetical studies and for eliminating highly susceptible progenies at an early stage in a breeding programme. R.L. Wastie died 16.01.96.  相似文献