Periodic orbit theory for Rydberg atoms in external fields

Although hydrogen in external fields is a paradigm for the application of periodic orbits and the Gutzwiller trace formula to a real system, the trace formula has never been applied successfully to other Rydberg atoms. We show that spectral fluctuations of general Rydberg atoms are given with remarkable precision by the addition of diffractive terms. Previously unknown features in atomic spectra are exposed: there are new modulations that are neither periodic orbits nor combinations of periodic orbits; “core shadowing” generally decreases primitive periodic orbit amplitudes but can also lead to increases

Topological defects in low-energy string gravity

Cosmologists are interested in topological defects as a possible source for the primordial density perturbations which seeded structure formation through gravitational instability. In this thesis, the gravitational properties of various topological defects are studied in the context of low-energy string theory, a likely modification of Einstein gravity at the high energy scales prevalent in the early universe. We consider in turn global monopole, local monopole, global cosmic string and global texture defects, allowing for an arbitrary coupling of defects to the string theory dilaton. For global defects we find the following behaviour. If the dilaton is massless, this modification to general relativity generically destroys the global good behaviour of the monopole and cosmic string, making their spacetimes singular. For the texture non-singular spacetimes exist, but only for certain values of the matter-dilaton coupling, dependent on the gravitational strength of the defect; in addition, this non-singular behaviour exists only in a certain frame. In the case of a massive dilaton, the metric behaviour of these defects is similar to that found in Einstein gravity, though we find they generically induce a long-range dilaton cloud. For the local monopole, which we study only in the presence of a massless dilaton, a rich variety of behaviour is found. For particular parameter values the local monopole spacetime approximates that of an extremal dilaton black hole

Global monopoles in dilaton gravity

We analyse the gravitational field of a global monopole within the context of low energy string gravity, allowing for an arbitrary coupling of the monopole fields to the dilaton. Both massive and massless dilatons are considered. We find that, for a massless dilaton, the spacetime is generically singular, whereas when the dilaton is massive, the monopole generically induces a long range dilaton cloud. We compare and contrast these results with the literature.Comment: 15 pages, 3 figures, version to appear in Class Quant Gra

Microarray profiling emphasizes transcriptomic differences between hippocampal in vivo tissue and in vitro cultures" for publication in Brain Communications.

From Crossref journal articles via Jisc Publications RouterHistory: epub 2021-07-07, issued 2021-07-07Article version: AMPublication status: PublishedAbstract Primary hippocampal cell cultures are routinely used as an experimentally accessible model platform for the hippocampus and brain tissue in general. Containing multiple cell types including neurons, astrocytes and microglia in a state that can be readily analysed optically, biochemically and electrophysiologically, such cultures have been used in many in vitro studies. To what extent the in vivo environment is recapitulated in primary cultures in an on-going question. Here we compare the transcriptomic profiles of primary hippocampal cell cultures and intact hippocampal tissue. In addition, by comparing profiles from wild type and the PrP 101LL transgenic model of prion disease, we also demonstrate that gene conservation is predominantly conserved across genetically altered lines

LAB-AID: an interactive web application for visualization of multi-level data from biological experiments

A key step in understanding the results of biological experiments is visualization of the data. Many laboratory experiments contain a range of measurements that exist within a hierarchy of interdependence. An automated and facile way to visualize and interrogate such multi-level data, across many experimental variables, would: 1) lead to improved understanding of the results, 2) help to avoid misleading interpretation of statistics, and 3) easily identify outliers and sources of batch and confounding effects. While many excellent graphing solutions already exist, they are often geared towards the production of publication-ready plots, the analysis of a single variable at a time, require programming expertise, or are unnecessarily complex for the task at hand. Here we present LAB-AID (Laboratory Automated Interrogation of Data), an interactive tool specifically designed to automatically visualize and query hierarchical data resulting from biological experiment

Distinct neuroinflammatory signatures exist across genetic and sporadic ALS cohorts

Acknowledgments This research was funded in part by the Wellcome Trust (108890/Z/15/Z) to OMR, a Pathological Society and Jean Shanks Foundation grant (JSPS CLSG 202002) to JMG and JOS, an NIH grant (5-R01-NS127186-02) to JMG, FMW, and JOS, a Motor Neuron Disease (MND) Scotland grant to JMG and CRS (2021/MNDS/RP/8440GREG), and a Sir Henry Dale Fellowship jointly funded by the Wellcome Trust and the Royal Society (215454/Z/19/Z) to CRS. For the purpose of open access, the author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission. This work would not be possible without the resources of the Edinburgh Brain Bank. The authors declare no conflicts of interest.Preprin