Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
1,149
result(s) for
"Moore, Graham"
Sort by:
Short periods of high temperature during meiosis prevent normal meiotic progression and reduce grain number in hexaploid wheat (Triticum aestivum L.)
Key message
Exposure of wheat to high temperatures during male meiosis prevents normal meiotic progression and reduces grain number. We define a temperature-sensitive period and link heat tolerance to chromosome 5D.
This study assesses the effects of heat on meiotic progression and grain number in hexaploid wheat (
Triticum aestivum
L. var. Chinese Spring), defines a heat-sensitive stage and evaluates the role of chromosome 5D in heat tolerance. Plants were exposed to high temperatures (30 or 35 °C) in a controlled environment room for 20-h periods during meiosis and the premeiotic interphase just prior to meiosis. Examination of pollen mother cells (PMCs) from immature anthers immediately before and after heat treatment enabled precise identification of the developmental phases being exposed to heat. A temperature-sensitive period was defined, lasting from premeiotic interphase to late leptotene, during which heat can prevent PMCs from progressing through meiosis. PMCs exposed to 35 °C were less likely to progress than those exposed to 30 °C. Grain number per spike was reduced at 30 °C, and reduced even further at 35 °C. Chinese Spring nullisomic 5D-tetrasomic 5B (N5DT5B) plants, which lack chromosome 5D, were more susceptible to heat during premeiosis–leptotene than Chinese Spring plants with the normal (euploid) chromosome complement. The proportion of plants with PMCs progressing through meiosis after heat treatment was lower for N5DT5B plants than for euploids, but the difference was not significant. However, following exposure to 30 °C, in euploid plants grain number was reduced (though not significantly), whereas in N5DT5B plants the reduction was highly significant. After exposure to 35 °C, the reduction in grain number was highly significant for both genotypes. Implications of these findings for the breeding of thermotolerant wheat are discussed.
Journal Article
Process evaluation of complex interventions: Medical Research Council guidance
Process evaluation is an essential part of designing and testing complex interventions. New MRC guidance provides a framework for conducting and reporting process evaluation studies
Journal Article
The Liues, Apprehensions, Arraignments, and Executions of the 19 Late Pyrates: Jacobean Piracy in Law and Literature
The 1609 pamphlet The liues, apprehensions, arraignments, and executions of the 19 late pyrates tells the stories of nineteen pirates trialled in 1609. Historians of Jacobean piracy have used this pamphlet as evidence, finding value in its detailed, dramatic accounts of maritime depredation—yet it has often escaped close textual analysis. This article analyses the pamphlet’s content and context, in doing so illuminating the tensioned relationship between legal, state, and popular cultural narratives of what constituted a “pirate”. The pamphlet provides an opportunity to further discuss the ambiguous, developing cultural role of piracy (and its perpetrators) at this time. It allows us to approach such questions as: which elements of a pirate’s story were interesting to the seventeenth-century audience, and which elements marked out acts of depredation as truly being “piracy”? How does the source approach legal proceedings, and digest them for popular consumption? What place does this pamphlet have in the wider canon of piracy’s print culture? This article suggests that the figure of the pirate could be redeemed, where it was reconcilable with the sensibilities of the terrestrial community—however, tensions arose when different groups imposed their own ideologies and intentions upon the criminal. These tensions appear in the differences between representations of maritime depredation emanating from the state and from the public—differences visible in the transmission of information from law to literature.
Journal Article
Wheat chromatin architecture is organized in genome territories and transcription factories
Background
Polyploidy is ubiquitous in eukaryotic plant and fungal lineages, and it leads to the co-existence of several copies of similar or related genomes in one nucleus. In plants, polyploidy is considered a major factor in successful domestication. However, polyploidy challenges chromosome folding architecture in the nucleus to establish functional structures.
Results
We examine the hexaploid wheat nuclear architecture by integrating RNA-seq, ChIP-seq, ATAC-seq, Hi-C, and Hi-ChIP data. Our results highlight the presence of three levels of large-scale spatial organization: the arrangement into genome territories, the diametrical separation between facultative and constitutive heterochromatin, and the organization of RNA polymerase II around transcription factories. We demonstrate the micro-compartmentalization of transcriptionally active genes determined by physical interactions between genes with specific euchromatic histone modifications. Both intra- and interchromosomal RNA polymerase-associated contacts involve multiple genes displaying similar expression levels.
Conclusions
Our results provide new insights into the physical chromosome organization of a polyploid genome, as well as on the relationship between epigenetic marks and chromosome conformation to determine a 3D spatial organization of gene expression, a key factor governing gene transcription in polyploids.
Journal Article
Synthesising quantitative and qualitative evidence to inform guidelines on complex interventions: clarifying the purposes, designs and outlining some methods
Guideline developers are increasingly dealing with more difficult decisions concerning whether to recommend complex interventions in complex and highly variable health systems. There is greater recognition that both quantitative and qualitative evidence can be combined in a mixed-method synthesis and that this can be helpful in understanding how complexity impacts on interventions in specific contexts. This paper aims to clarify the different purposes, review designs, questions, synthesis methods and opportunities to combine quantitative and qualitative evidence to explore the complexity of complex interventions and health systems. Three case studies of guidelines developed by WHO, which incorporated quantitative and qualitative evidence, are used to illustrate possible uses of mixed-method reviews and evidence. Additional examples of methods that can be used or may have potential for use in a guideline process are outlined. Consideration is given to the opportunities for potential integration of quantitative and qualitative evidence at different stages of the review and guideline process. Encouragement is given to guideline commissioners and developers and review authors to consider including quantitative and qualitative evidence. Recommendations are made concerning the future development of methods to better address questions in systematic reviews and guidelines that adopt a complexity perspective.
Journal Article
Dual effect of the wheat Ph1 locus on chromosome synapsis and crossover
Allopolyploids must possess a mechanism for facilitating synapsis and crossover (CO) between homologues, in preference to homoeologues (related chromosomes), to ensure successful meiosis. In hexaploid wheat, the
Ph1
locus has a major effect on the control of these processes. Studying a wheat mutant lacking
Ph1
provides an opportunity to explore the underlying mechanisms. Recently, it was proposed that
Ph1
stabilises wheat during meiosis, both by promoting homologue synapsis during early meiosis and preventing MLH1 sites on synapsed homoeologues from becoming COs later in meiosis. Here, we explore these two effects and demonstrate firstly that whether or not
Ph1
is present, synapsis between homoeologues does not take place during the telomere bouquet stage, with only homologous synapsis taking place during this stage. Furthermore, in wheat lacking
Ph1
, overall synapsis is delayed with respect to the telomere bouquet, with more synapsis occurring after the bouquet stage, when homoeologous synapsis is also possible. Secondly, we show that in the absence of
Ph1
, we can increase the number of MLH1 sites progressing to COs by altering environmental growing conditions; we show that higher nutrient levels in the soil or lower temperatures increase the level of both homologue and homoeologue COs. These observations suggest opportunities to improve the exploitation of the
Ph1
wheat mutant in breeding programmes.
Journal Article
School, Peer and Family Relationships and Adolescent Substance Use, Subjective Wellbeing and Mental Health Symptoms in Wales: a Cross Sectional Study
Positive relationships with family, friends and school staff are consistently linked with health and wellbeing during adolescence, though fewer studies explore how these micro-systems interact to influence adolescent health. This study tests the independent and interacting roles of family, peer and school relationships in predicting substance use, subjective wellbeing and mental health symptoms among 11–16 year olds in Wales. It presents cross-sectional analyses of the 2013 Health Behaviour in School-aged Children survey, completed by 9055 young people aged 11–16 years. Multilevel logistic regression analyses are used to test associations of family communication, family support, relationships with school staff, school peer connectedness, and support from friends, with tobacco use, cannabis use, alcohol use, subjective wellbeing and mental health symptoms. Positive relationships with family and school staff were consistently associated with better outcomes. Support from friends was associated with higher use of all substances, while higher school peer connectedness was associated with better subjective wellbeing and mental health. Better relationships with school staff were most strongly associated with positive subjective wellbeing, and fewer mental health symptoms where pupils reported less family support. Support from friends was associated with higher cannabis use and worse mental health among pupils with lower family support. Relationships with family and school staff may be important in protecting young people against substance use, and improving wellbeing and mental health. Interventions focused on student-staff relationships may be important for young people with less family support. Interventions based on peer support should be mindful of potential harmful effects for pupils with less support from family.
Journal Article