657 research outputs found

    A comparison of new and existing rootstocks to reduce canker of apple trees caused by Neonectria ditissima (Nectriaceae, Hypocreales)

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    The grafting of apple rootstocks on to scions confers benefts including reduced tree size/dwarfng for trellis based growing systems, increased tolerance to physiological stress, and pest and disease management. The current study investigated the efect of rootstock selection on canker and tree death using eight common rootstocks M9 337, M9 337 with Golden Delicious (GD) interstock, M9 EMLA, MM106, M116, M26, Geneva® G11 and G41, in addition to six advanced selections from the NIAB East Malling apple breeding programme EMR-001—EMR-006, all grafted with Gala scions. One of the rootstocks, M9 377 was also grafted with a GD interstock. Two locations in England were selected, the frst at East Malling, Kent, the second, at Newent, Gloucestershire. Several variables were analysed including cumulative numbers of dead trees per rootstock from 2017 to 2020, number of rootstock ‘A type’ cankers, number of scion mainstem ‘B type’ cankers, and number of peripheral ‘C+D+E’ branch cankers at the Kent and Gloucestershire locations in the fourth and fnal assessment year of 2020. Kendall’s rank correlation was used to test if trunk circumference (a measure of tree vigour) and canker were statistically dependant. Results showed that in Kent, there were signifcant diferences between rootstocks for scion B cankers and peripheral C+D+E cankers. There were no signifcant diferences found between rootstocks for rootstock A cankers at Kent, or any of the three canker types in Gloucestershire. There were up to 31.25% dead trees in Kent (EMR-004), and 30% in Gloucestershire (M9 337 with GD interstock, M26), but there were no signifcant diferences in number of dead trees due to rootstock type in either Kent or Gloucestershire. The Kendall’s rank correlation analysis indicated there was almost no dependence of trunk circumference on canker. The three rootstocks with the overall lowest susceptibility to canker were M116, EMR-006, and EMR-004. The industry standard rootstocks M9 EMLA and M9 337 were ranked 12 and 14, and with EMR-001 were the three worst performing rootstocks. The Geneva® rootstocks G11 was ranked 6, and G41 was ranked 11. An interplay of factors are likely involved in the development of canker including location and environmental efects—rainfall, relative humidity, temperature, wind, soil type, topography, aspect, and other seasonal infection processes including pathogen inoculum load, and rainsplash of inoculum between trees and within individual trees, the genetics and physiology of each scion/rootstock combination, water and nutritional status of trees, hormonal and molecular signalling, and orchard management including pruning and removal of cankers

    Catching on to concatenation : evidence for prepollination intrasexual selection in plants

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    [from introduction] Darwin (1871) proposed the mechanism of sexual selection to explain the extreme traits, secondary sex characters, seen primarily in male animals for either display or competition. These elaborate traits for attracting members of the opposite sex or competing for access to mates, inter- and intra-sexual selection, respectively, would increase the mating success of individuals but may reduce individual survival. Sexual selection has traditionally been associated with motile, dioecious animals that have well-developed sensory abilities and has long been viewed as absent as a mode of selection in plants (Grant, 1995). However, since the 1980s, several workers have argued that sexual selection is applicable to plants and should be considered as a factor in floral evolution (Skogsmyr & Lankinen, 2002). Opponents such as Grant (1995) point to incompatibility with Darwin’s usage, hermaphroditism, the absence of obvious secondary sex characters and the apparent absence of female choice in plants (Skogsmyr & Lankinen, 2002; Moore & Pannell, 2011). Proponents, however, argue that historical definitions should be expanded to explain modern evidence and that sexual selection can, in principle, occur in hermaphrodites and hence play a role in the evolution of floral traits. The latter view is supported by a recent study by Cocucci et al. (this issue of New Phytologist, pp. 280–286) which demonstrates intra-sexual selection in plants via direct male–male competition between the pollinaria of milkweeds for optimal attachment sites on pollinators to ensure subsequent pollinium deposition. This is the first example of male–male competition resulting in secondary sex characters in hermaphrodite plants, highlighting the possibility of overlooked mechanisms of sexual selection in plants

    A comparative study of oxygen and hydrogen adsorption on strained and alloy-supported Pt(111) monolayers

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    A comparative study of the unreacted and reacted uniaxially strained Pt(111) and the layered (111)-Pt/Ni/Pt3Ni and (111)-Pt/Ni/PtNi3 surfaces has been performed using density functional theory (DFT). An in-depth study of the unreacted surfaces has been performed to evaluate the importance of geometric, magnetic and ligand effects in determining the reactivity of these different Pt surfaces. An analysis of the binding energies of oxygen and hydrogen over the high-symmetry binding positions of all surfaces has been performed. The study has shown that O and H tend to bind more strongly to the (111)-Pt/Ni/Pt3Ni surface and less strongly to the (111)-Pt/Ni/PtNi3 surface compared to binding on the equivalently strained Pt(111) surfaces. Changes in the surface magnetisation of the surfaces overlaying the ferromagnetic alloys during adsorption are discussed, as well as the behaviour of the d-band centre across all surfaces, to evaluate the potential mechanisms for these differences in binding. An accompanying comparison of the accessible density functionals has been included to estimate the error in the computational binding energies

    Residential mobility in divided societies: How individual religion and geographical context influenced housing moves in Northern Ireland 2001–2011

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    Residential segregation is pervasive in many societies. People making residential moves in these divided contexts may increase or decrease segregation levels. In this paper, the divided society of Northern Ireland is used as an example to explore how residential mobility relates to residential segregation by religion. Survey evidence for this country consistently shows a preference for mixed neighbourhoods, yet actual patterns of geographical mobility suggest people move to same‐religion areas. The paper uses the Northern Ireland Longitudinal Study (NILS) to explore the individual and contextual factors that influence the destinations of internal migrants by religion between 2001 and 2011. How they move up or down the contextual ‘religion ladder’ of localities is modelled with reference to both their individual socio‐demographic and neighbourhood characteristics in 2001. It is found that there are still individual religious differentials in people's destinations. Catholics, for instance, are more likely than Protestants to move to more Catholic areas, suggesting that individual religion remains important despite the Peace Process. Some possible reasons for this are considered with a partial explanation being found in the geographical patterning of the population. Existing patterns of residential segregation constrain moves in religious space for the majority of people. It is concluded, nevertheless, that an individual's religion remains a considerable factor contrary to expectations

    The Spatial-temporal Exploration Health and Housing Tenure Transitions Using the Northern Ireland Longitudinal Study

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    The nature and value of the Northern Ireland Longitudinal Study (NILS) is demonstrated through a statistical analysis of changes in individuals' health status, housing tenure and residential movement between the 2001 and 2011 Censuses. Multilevel analysis of individuals located within Super Output Areas, and also aggregate mapping of Local Indicators of Spatial Association (LISA) using 2011 Census Area Statistics are undertaken. Over the ten year period in which some people report worsening of their health whilst others experience an improvement, we show how probabilities in health transition are related to starting tenure as well changes in tenure and address between 2001 and 2011. We also provide evidence of distinctive 2011 geographies of self-reported illness and housing tenure, and suggest that spatial context does matter to a degree for individual health transitions. The chapter concludes with a reflection on the analyses presented, consideration of potential future research applications using the NILS, and also some general observations on the changing data landscape

    Not going out during the Covid-19 pandemic? A multilevel geographical analysis of UK Google Mobility Reports, February 2020–December 2021

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    The analysis reported in this paper uses Google Mobility Reports to understand subnational trends in population spatial immobility/mobility in the United Kingdom during 2020 and 2021. Using multilevel modelling, it analyses how spatial mobility changed through time in response to the strictness of government lockdown and the annual seasonal cycle of public holidays, and between places in terms of their population composition as measured by the shares of the highly-educationally qualified and the self-employed. The results show that there are no consistent differences between the nations of the United Kingdom; that time spent at home increased with the severity of lockdown; that the share of highly qualified was also a good predictor of staying at home; and that there were major effects from public holidays. The analysis did not explain all the variation between places and dates; it is suggested that this is because of randomisation of the data by Google and unmodelled factors such as tiered restrictions

    Spatial mobility and tolerance towards immigrants: the case of Northern Iceland

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    While the profound effects of spatial mobility on social structures and patterns of interactions have long been recognized, the association of mobility experiences and tolerance towards immigrants has received limited attention. In this paper, we examine such patterns in Iceland, a country with a long history of emigration and return migration of the local population but a recent surge in international immigration. We find in-migrants and locals who have lived in the capital city area or abroad for at least a year to be more tolerant of immigrants than locals who have never lived elsewhere. These patterns of tolerance among more mobile respondents persist after controlling for other predictors such as age, gender, education and language skills, employment status, income, community integration, residential satisfaction and generalized trust. These results are discussed in the context of changing patterns of mobility and immobility in western countries

    9. Longitudinal studies in the United Kingdom

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    The collection of reliable and comprehensive data on the magnitude, composition and distribution of a country’s population is essential in order for governments to provide services, administer effectively and guide a country’s ..

    Uso de residuos de la industria del mármol como filler para la producción de hormigones autocompactantes

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    This study evaluates the possibilities of using residual slurry from the cutting and superficial treatment of marble for the production of self-compacting concrete (SCC). The study considers the replacement of 30% of cement by the waste material, and assessed the effects on SCC properties in fresh and hardened states. Rheological characteristics were evaluated at the paste and concrete levels. Physical-mechanical characterization considers the rate of shrinkage and compressive strength gain. Pastes and concrete properties using waste marble as filler are compared with mixtures that include limestone filler, either added to the concrete or the cement. For the same dosage, an improvement in the flowability was observed in SCC with waste marble filler. The mechanical properties of the SCC adopting marble waste are equivalent to the SCC with limestone filler. The study shows that residual slurry from the processing of marble can represents an appropriate filler to be used in SCC.El presente estudio evalúa las posibilidades de utilización de lodos residuo de la industria del corte y tratamiento superficial del mármol para la producción de hormigón autocompactante (HAC). Se estudia el efecto del remplazo de un 30% del cemento por el residuo. Se valoran las características reológicas a nivel pasta y hormigón. La caracterización físico-mecánica contempla la evolución de la retracción y de la resistencia a compresión. Se comparan las prestaciones de pastas y hormigones empleando el residuo con mezclas que incorporan filler calizo, ya sea adicionado al hormigón o presente en el cemento. Se observa una mejora de la fluidez en el caso de los HAC que contienen el residuo estudiado; las propiedades mecánicas de éstos resultan equivalentes a las de los HAC con filler calizo. Se concluye que los lodos residuo del procesamiento del mármol pueden representan un filler adecuado para su uso en HAC
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