On the fine structure of medium energy electron fluxes in the auroral zone and related effects in the ionospheric D-region

This study is based on measurements of trapped and precipitated electrons of energy &gt;30 keV and &gt;100 keV observed by polar orbiting environmental satellites during overpasses of the imaging riometer at Kilpisjärvi, Finland. The satellites are in sun-synchronous orbits of about 850 km altitude, recording the electron fluxes at 2-s time resolution. The riometer measures the radiowave absorption at 38.2 MHz, showing the spatial pattern within a 240 km field of view. <br><br> The analysis has focussed on two areas. Having found a close correlation between the radiowave absorption and the medium-energy electron fluxes during satellite overpasses, empirical relationships are derived, enabling one quantity to be predicted from the other for three sectors of local time. It is shown that small-scale variations observed during a pass are essentially spatial rather than temporal. <br><br> Other properties, such as the spectra and the relation between precipitated and trapped components, are also considered in the light of the theory of pitch angle scattering by VLF waves. It is found that the properties and behaviour depend strongly on the time of day. In the noon sector, the precipitated and trapped fluxes are highly correlated through a square law relationship

Biotechnology value chains as a case study of the knowledge economy : the relationship between knowledge, space and technology

The overall scope of this thesis is to consider the relationship between knowledge, space and technology in the ‘knowledge economy’ by drawing upon biotechnology value chains as a case study of the knowledge economy. Central to this is the claim that although biotechnology is an internationally distributed sector, it is also concentrated in specific places because those locations provide an advantage through dynamic innovation processes. Such processes are embedded in places because those places have a particular set of knowledge inputs and provide access to other knowledge inputs outwith those places. In this sense, the knowledge economy can be seen as dependent upon different places and scales that all contribute to the innovation process and therefore necessitate relationships within and between different and diverse locations. The major contribution to knowledge that the thesis provides is the development of a new conceptual understanding of innovation processes called the knowledge-space dynamic that focuses on the knowledge and spatial features of the innovation process rather than assuming that the concentration of innovation necessarily entails specific knowledge and spatial characteristics. Consequently the thesis picks apart the current emphasis on certain types of knowledge (e.g. tacit and explicit) to explore the ways in which these are combined in the innovation process and embedded in particular places. Thus the research approach in the thesis adopts a new methdological framework to collect and analyse secondary and primary data that has not been previously undertaken. Overall the thesis conclusion is that the knowledge economy – and especially the biotech industry – may not represent the best method for regional development

Precise measurements of UV atomic lines: Hyperfine structure and isotope shifts in the 398.8 nm line of Yb

We demonstrate a technique for frequency measurements of UV transitions with sub-MHz precision. The frequency is measured using a ring-cavity resonator whose length is calibrated against a reference laser locked to the $D_2$ line of $^{87}$Rb. We have used this to measure the 398.8 nm ${^1S}_0 \leftrightarrow {^1P}_1$ line of atomic Yb. We report isotope shifts of all the seven stable isotopes, including the rarest isotope $^{168}$Yb. We have been able to resolve the overlapping $^{173}$Yb($F = 3/2$) and $^{172}$Yb transitions for the first time. We also obtain high-precision measurements of excited-state hyperfine structure in the odd isotopes, $^{171}$Yb and $^{173}$Yb. The measurements resolve several discrepancies among earlier measurements.Comment: 7 pages, 6 figure

Helioseismology of Pre-Emerging Active Regions II: Average Emergence Properties

We report on average subsurface properties of pre-emerging active regions as compared to areas where no active region emergence was detected. Helioseismic holography is applied to samples of the two populations (pre-emergence and without emergence), each sample having over 100 members, which were selected to minimize systematic bias, as described in Leka et al. We find that there are statistically significant signatures (i.e., difference in the means of more than a few standard errors) in the average subsurface flows and the apparent wave speed that precede the formation of an active region. The measurements here rule out spatially extended flows of more than about 15 m/s in the top 20 Mm below the photosphere over the course of the day preceding the start of visible emergence. These measurements place strong constraints on models of active region formation.Comment: 15 pages, 10 figures, ApJ (published

Validating Forward Modeling and Inversions of Helioseismic Holography Measurements

Here we use synthetic data to explore the performance of forward models and inverse methods for helioseismic holography. Specifically, this work presents the first comprehensive test of inverse modeling for flows using lateral-vantage (deep-focus) holography. We derive sensitivity functions in the Born approximation. We then use these sensitivity functions in a series of forward models and inversions of flows from a publicly available magnetohydrodynamic quiet-Sun simulation. The forward travel times computed using the kernels generally compare favorably with measurements obtained by applying holography, in a lateral-vantage configuration, on a 15-hour time series of artificial Dopplergrams extracted from the simulation. Inversions for the horizontal flow components are able to reproduce the flows in the upper 3Mm of the domain, but are compromised by noise at greater depths.Comment: accepted for publication by the Astrophysical

Calculated elastic and electronic properties of MgB2_2 at high pressures

The effect of high pressure on structural and electronic properties of the novel superconductor \MB has been calculated using the full-potential linearized augmented-plane-wave method. Despite the layered crystal structure of \MB nearly isotropic compression (bulk modulus $B_0=140.1(6)$ GPa) is found with only a 1.2% decrease of the $c/a$ ratio at 10 GPa. The effect of pressure on the critical temperature has been estimated on the basis of BCS theory and good agreement with experimental data is found. Our results suggest that it is a combination of increasing phonon frequency and decreasing electronic density of states at the Fermi level which leads to the observed decrease of the critical temperature under pressure.Comment: 10 pages, 3 figures (EPS), Elsevier LaTeX. More detailed analysis of the pressure dependence of Tc; results unchanged. Manuscript accepted for publication in Solid State Commu

A Critical Analysis of UK International Health Partnerships: The Discourse of Mental Health

Background The work of International Health Partnerships (IHPs) is a way of working with Low- and Middle-Income Countries to address issues of Global Health and more recently Global Mental Health. They have come about through various political constructs such as over the Millennium Development Goals. The researcher provides and overview for the political context before using a scoping review to demonstrate the gaps in existing literature. These gaps informed the construction of this research which aimed to explore how the work of IHPs is communicated and how these forms of communication related to the wider debate surrounding the ethics and utility of IHPs. Method The researcher carried out a Critical Discourse Analysis on project reports that documented the progress of IHPs addressing mental health concerns. The analysis critically explored the structural and discursive features of these documents. Results The results obtained highlighted issues with the construction of the documents used to capture development, as well as concerns about the rhetorical devices and discourses used in the communication of IHP work which constituted a form of testimonial injustice. Conclusion In order to progress to an equitable form of health partnership changes need to be made at all levels to take make the rhetoric around the good of global health more than hollow words

Reliability of Semiautomated Kinetic Perimetry (SKP) and Goldmann Kinetic Perimetry in Children and Adults With Retinal Dystrophies.

PurposeTo investigate the precision of visual fields (VFs) from semiautomated kinetic perimetry (SKP) on Octopus 900 perimeters, for children and adults with inherited retinal degenerations (IRDs). Goldmann manual kinetic perimetry has long been used in the diagnosis and follow-up of these patients, but SKP is becoming increasingly common. Octopus VFs (OVFs) and Goldmann VFs (GVFs) were both mapped on two occasions.MethodsNineteen females and 10 males with IRDs were tested on OVFs and GVFs, with two targets per test (V4e and one smaller target). Tests were performed in the same (randomized) order at two visits about 1 week apart. The VFs were digitized to derive isopter solid angles. Comparisons, within and between visits, were performed with paired t-tests and Bland-Altman plots.ResultsMedian age was 20 years (range, 7-70; 10 participants aged ≤17 years old). There were no significant differences in solid angles between OVFs and GVFs (P ≥ 0.06) or between the two visits' solid angles on either perimeter (P ≥ 0.30). Between-visit test-retest variability for GVFs and OVFs was similar (P ≥ 0.73), with median values of approximately 9% to 13%. Overall variability was lower for children than adults (medians of 7.5% and 12.8%, respectively).ConclusionsOctopus SKP and Goldmann perimetry produced VFs of similar size and variability.Translational relevanceOur study indicates that SKP provides a viable alternative to traditional Goldmann perimetry in clinical trials or care involving both children and adults with IRDs