930 research outputs found
Modelling the burden caused by gene expression: an in silico investigation into the interactions between synthetic gene circuits and their chassis cell
In this paper we motivate and develop a model of gene expression for the
purpose of studying the interaction between synthetic gene circuits and the
chassis cell within which they are in- serted. This model focuses on the
translational aspect of gene expression as this is where the literature
suggests the crucial interaction between gene expression and shared resources
lies
A theoretical and computational study of heterogeneous spatio-temporal distributions arising from density-dependent animal movement with applications to slugs in arable fields
Understanding the dynamics of pest populations is essential for pest management in agriculture. Slugs alone can cause large amounts of economic damage if their population is not controlled, usually by the application of chemical pesticides. However, there is pressure to reduce the amount of pesticide used because of the potential effects on human health and the environment. One solution to this problem is to target the application of pesticide only on areas of high population density.
This thesis thoroughly investigates the mechanisms in individual movement that can lead to the formation of heterogeneous spatial distributions in a population. Using an individual based model, we show that when an animal's direction of movement is dependent on the population density in its immediate surroundings, the population can form several clusters of high density. We show that the characteristics of the clusters and their temporal stability are dependent on how individual animals move, with Brownian motion producing dense stable clusters and Lévy flight producing dynamic clusters that are highly volatile. We confirm the existence of density dependent movement behaviour through an analysis of spatial tracking data from a field experiment where slugs were released in either a group or individually. Differences in individual movement seen in the data are shown to produce a heterogeneous population distribution through another individual based model. Finally, we analyse data of slug trap counts and discuss methods that can be used for identifying high density patches that should be targeted by pesticide
Development of manganese (VI) oxidising agents soluble in organic solvents
Two manganate (VI) reagents have been prepared from permanganate salts that show excellent oxidizing properties in common organic solvants
The prevalence and practices of caffeine use as an ergogenic aid in English professional soccer:Caffeine Use In Professional Soccer
The ergogenic properties of caffeine are well established, with evidence supporting beneficial effects for physical and technical elements of performance required for successful soccer match play. Despite this, recommended caffeine practices for professional soccer have not been established. Therefore, the present study aimed to evaluate the use and behaviours surrounding caffeine use in elite English soccer clubs. Representatives of 36 clubs from the top four tiers of English professional football (40%) completed an online survey that sought to determine if, when, how and why caffeine was prescribed to players as a means of improving sports performance. Of the clubs sampled, 97% indicated that caffeine is provided to players as a means of improving performance. Caffeine is most commonly administered prior to (> 94%) and during a game (> 48%), with frequency uninfluenced by time of matches. There was a broad range and lack of consistency in the timing, dose and mode of caffeine administration, but doses were typically low. Evidence from the present study indicate a translational gap between science and practice, highlighting a need for future work to better understand how caffeine consumption can be optimised with respect to the specific demands and constraints in professional soccer
The Influence of Recruitment Age and Anthropometric and Physical Characteristics on the Development Pathway of English Academy Football Players
Purpose: This study aims firstly to investigate the influence of recruitment age on retention and release across the development pathway. Secondly, the study aims to explore the influence of anthropometric and physical characteristics on retention and release at different ages throughout the development pathway and the likelihood of obtaining a professional contract. Methods: Following ethics approval, a cross-sectional study tracking 4 cohorts of players over 5 years assessed 76 male youth football players (11-16 years) from an English football academy on three occasions annually in anthropometry, countermovement jump height, linear (30m and 15m) and multidirectional sprint time. Players were categorised based on their start and release date. Results: Starting early (i.e. before U12) in an academy was a key indicator of obtaining a professional contract, representing 87% of the players signed. Bayesian regression models suggest that the majority of differences in physical characteristics between players that were released and retained are trivial, small and / or uncertain. Players who attained a professional contract at 18 had slower 15m and 30m sprint times at U13-U15 (P>0=0.87–0.99), slower multidirectional sprint times at U14 (P>0=0.99) and a lower countermovement jump height at U13-U16 (P>0=0.88-0.99) compared with players who did not gain a contract. Conclusion: Players recruited early have an increased likelihood of gaining a professional contract. Physical assessments lack utility when used in isolation as a talent identification tool
Modeling seizures in the Human Phenotype Ontology according to contemporary ILAE concepts makes big phenotypic data tractable.
OBJECTIVE: The clinical features of epilepsy determine how it is defined, which in turn guides management. Therefore, consideration of the fundamental clinical entities that comprise an epilepsy is essential in the study of causes, trajectories, and treatment responses. The Human Phenotype Ontology (HPO) is used widely in clinical and research genetics for concise communication and modeling of clinical features, allowing extracted data to be harmonized using logical inference. We sought to redesign the HPO seizure subontology to improve its consistency with current epileptological concepts, supporting the use of large clinical data sets in high-throughput clinical and research genomics.
METHODS: We created a new HPO seizure subontology based on the 2017 International League Against Epilepsy (ILAE) Operational Classification of Seizure Types, and integrated concepts of status epilepticus, febrile, reflex, and neonatal seizures at different levels of detail. We compared the HPO seizure subontology prior to, and following, our revision, according to the information that could be inferred about the seizures of 791 individuals from three independent cohorts: 2 previously published and 150 newly recruited individuals. Each cohort\u27s data were provided in a different format and harmonized using the two versions of the HPO.
RESULTS: The new seizure subontology increased the number of descriptive concepts for seizures 5-fold. The number of seizure descriptors that could be annotated to the cohort increased by 40% and the total amount of information about individuals\u27 seizures increased by 38%. The most important qualitative difference was the relationship of focal to bilateral tonic-clonic seizure to generalized-onset and focal-onset seizures.
SIGNIFICANCE: We have generated a detailed contemporary conceptual map for harmonization of clinical seizure data, implemented in the official 2020-12-07 HPO release and freely available at hpo.jax.org. This will help to overcome the phenotypic bottleneck in genomics, facilitate reuse of valuable data, and ultimately improve diagnostics and precision treatment of the epilepsies
Marconi, masculinity and the heroic age of science: wireless telegraphy at the British Association meeting at Dover in 1899
In September 1899, at the annual meeting of the British Association for the Advancement of Science (BAAS) in Dover, Guglielmo Marconi’s wireless telegraphy system was used to transmit messages across the English Channel (and across a national border) for the first time. This achievement represented a highly effective performance of scientific masculinity and constitutes a key turning point in an important struggle between competing interpretations of invention and innovation as masculine practices within British science. The British Association tended to favor a narrative of scientific research as a collectivist, international, gentlemanly-amateur pursuit, largely confined to the laboratory. Marconi, by contrast, explained the development of wireless telegraphy as the achievement of his own genius. Appealing not only to the established scientific elite but to a range of non-traditional audiences, and stressing the possibilities or ‘imagined uses’ of his technology even more so than his actual results, he succeeded in commanding unprecedented influence
SARS-CoV-2 omicron BA.5 and XBB variants have increased neurotropic potential over BA.1 in K18-hACE2 mice and human brain organoids
The reduced pathogenicity of the omicron BA.1 sub-lineage compared to earlier variants is well described, although whether such attenuation is retained for later variants like BA.5 and XBB remains controversial. We show that BA.5 and XBB isolates were significantly more pathogenic in K18-hACE2 mice than a BA.1 isolate, showing increased neurotropic potential, resulting in fulminant brain infection and mortality, similar to that seen for original ancestral isolates. BA.5 also infected human cortical brain organoids to a greater extent than the BA.1 and original ancestral isolates. In the brains of mice, neurons were the main target of infection, and in human organoids neuronal progenitor cells and immature neurons were infected. The results herein suggest that evolving omicron variants may have increasing neurotropic potential
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