212 research outputs found
Trachipleistophora hominis infection in the myocardium and skeletal muscle of a patient with AIDS
No full textCurry, A. ; Beeching, N.J. ; Gilbert, J.D. ; Scott, G. ; Rowland, P.L. ; Currie, B.J
Photoelectron spectroscopy of atomic oxygen using the Elettra synchrotron source
No full textAtomic oxygen has been studied using angle resolved photoelectron spectroscopy (PES) and constant-ionic-state (CIS) measurements using radiation from the Elettra synchrotron as the photon source. Relative partial photoionization cross-sections and angular distributions for the O+(S-4) ? O(P-3) and O+(D-2) ? O(P-3) ionizations have been measured as a function of photon energy from threshold (13.6 eV) to 19.0 eV. Comparison of the results obtained with recent experimental work performed at lower resolution reveals a number of differences and comparison with results of recent calculations shows the need for the inclusion of coupling intermediate between the j-j and L-S limits in future calculations of photoionization cross-sections and angular distributions. This work has demonstrated the feasibility of and results to be expected from angle resolved PES and CIS measurements on reactive intermediates at Elettra, a third-generation synchrotron source, and further studies on small molecular radicals are proposed
Photoelectron spectroscopy of atomic oxygen using the Elettra synchrotron source
No full textAtomic oxygen has been studied using angle resolved photoelectron spectroscopy (PES) and
constant-ionic-state (CIS) measurements using radiation from the Elettra synchrotron as the
photon source. Relative partial photoionization cross-sections and angular distributions for
the Oþð4SÞ Oð3PÞ and Oþð2DÞ Oð3PÞ ionizations have been measured as a function of
photon energy from threshold (13.6 eV) to 19.0 eV. Comparison of the results obtained with
recent experimental work performed at lower resolution reveals a number of differences and
comparison with results of recent calculations shows the need for the inclusion of coupling
intermediate between the j–j and L–S limits in future calculations of photoionization crosssections
and angular distributions. This work has demonstrated the feasibility of and results to
be expected from angle resolved PES and CIS measurements on reactive intermediates at
Elettra, a third-generation synchrotron source, and further studies on small molecular radicals
are proposed
Study of the electronic structure of the actinide tetrabromides ThBr4 and UBr4 using ultraviolet photoelectron spectroscopy and density functional calculations
No full textUltraviolet photoelectron spectra of UBr4 and ThBr4 have been recorded in the gas-phase and interpreted using relativistic density functional calculations. For ThBr4, eight bands were observed which are interpreted as ionization from the five Br 4p symmetry orbitals of a Br-4 unit in T-d symmetry, with three of the bands [the (4t(2))(-1), (1t(1))(-1), and (3t(2))(-1) ionizations] each being split into two by spin-orbit interaction. The observed splittings are rationalized in terms of the Th 6p and Br 4p contributions to the orbitals and by comparison with the known ultraviolet photoelectron spectra of ThF4 and ThCl4. The first vertical ionization energy (VIE) of ThBr4 was measured as (10.92 +/-0.03) eV. UBr4 shows a very similar photoelectron spectrum with an extra band at (9.65 +/-0.02) eV VIE. This is associated with a (5t(2))(-1) (U 5f,6d) ionization. Supporting matrix isolation infrared experiments were also carried out under very similar vaporization conditions to those used in the photoelectron spectroscopy experiments to check the composition of the vapor beams used. In these experiments, the T-2 stretching modes of ThBr4 and UBr4 have been measured as 230 +/-2 and 239 +/-2 cm(-1), respectively. Both the photoelectron and infrared matrix isolation spectra are consistent with an effective tetrahedral geometry for UBr4 and ThBr4
The Spatial Impacts of a Massive Rail Disinvestment Program: The Beeching Axe
No full textTransport investment is a popular policy instrument and many recent studies have investigated whether new infrastructure generates economic benefits and has spatial economic impacts. Our work approa ches the question differently and looks at what happens when a substantial part of a national railway network is dismantled, as happened during the 1950s, 60s and 70s in Britain. Part of this disinvestment occurred following controversial reports on railwa y profitability and structure in the early 1960s – a course of action known colloquially as ‘the Beeching Axe’ after the author of the reports. The removal of railways is often blamed for the decline of rural areas and peripheral towns in post -war Britain. This rail disinvestment program was targeted at removal of underused and unprofitable lines and not specifically targeted at local economic performance. Even so, we find that there is a relationship between pre -war population decline and the depth of the rail cuts in the post 1950 period. Conditional on these pre -trends, we show that loss of access by rail did cause relative population decline, decline in the proportion of skilled workers, and decline in the proportion of young people in affected areas. The elasticity of population with respect to changes in centrality (or mark et access) is around 0.3 in our main estimates. Instrumental variables estimates based on the network structure of the cuts yield higher elasticities. An implication of these findings is that rail transport infrastructure plays an important role in shaping the spatial structure of the economy
Analysing and modelling train driver performance
No full textArguments for the importance of contextual factors in understanding human performance have been made extremely persuasive in the context of the process control industries. This paper puts these arguments into the context of the train driving task, drawing on an extensive analysis of driver performance with the Automatic Warning System (AWS). The paper summarises a number of constructs from applied psychological research which are thought to be important in understanding train driver performance. A “Situational Model” is offered as a framework for investigating driver performance. The model emphasises the importance of understanding the state of driver cognition at a specific time (“Now”) in a specific situation and a specific context
The spatial impacts of a massive rail disinvestment program: the Beeching Axe
No full textTransport investment is a popular policy instrument and many recent studies have investigated whether new infrastructure generates economic benefits and has spatial economic impacts. Our work approaches the question differently and looks at what happens when a substantial part of a national railway network is dismantled, as happened during the 1950s, 60s and 70s in Britain. Part of this disinvestment occurred following controversial reports on railway profitability and structure in the early 1960s – a course of action known colloquially as ‘the Beeching Axe’ after the author of the reports. The removal of railways is often blamed for the decline of rural areas and peripheral towns in post-war Britain. This rail disinvestment program was targeted at removal of underused and unprofitable lines and not specifically targeted at local economic performance. Even so, we find that there is a relationship between pre-war population decline and the depth of the rail cuts in the post 1950 period. Conditional on these pre-trends, we show that loss of access by rail did cause relative population decline, decline in the proportion of skilled workers, and decline in the proportion of young people in affected areas. The elasticity of population with respect to changes in centrality (or market access) is around 0.3 in our main estimates. Instrumental variables estimates based on the network structure of the cuts yield higher elasticities. An implication of these findings is that rail transport infrastructure plays an important role in shaping the spatial structure of the economy
Angle resolved photoelectron spectroscopy of O-2(a(1)Delta(g)) with synchrotron radiation
No full textAngular distribution of photoelectrons for the photoionization processes O-2(+)(X (2)Pi(g), upsilon(+) = 0-3) + e(-) <-- O-2(a(1) Delta(g)) + h nu has been studied at the photon energy of 21.22 eV and in the photon energy range 13.8-15.2 eV where the cross-sections for these processes show strong enhancement due to the presence of resonant transitions to a Rydberg state (C (2)Phi(u),3s sigma(g))p (1)Phi(u). It has been found that the plot of the asymmetry parameter, beta, against photon energy shows structure at energies corresponding to O-2(p (1)Phi(u)upsilon(')) <-- O-2(a (1)Delta(g)upsilon " = 0) excitations. The O-2(+)(X (2)Pi(g),upsilon(+)) <-- O-2(a (1)Delta(g),upsilon " = 0) ionizations have also been investigated in the photon energy range 18.0-19.2 eV, where the presence of unassigned resonances was observed in earlier photoelectron spectroscopic work. In this energy range the plot of asymmetry parameter against photon energy also shows resonant structure. Suggestions for the excited states associated with these resonances have been made on the basis of constant-ionic-state spectra recorded at different angles
Training and assessment of medical specialists in clinical microbiology and infectious diseases in Europe
No full textBackground: There is wide variation in the availability and training of specialists in the diagnosis and management of infections across Europe. Objectives: To describe and reflect on the current objectives, structure and content of European curricula and examinations for the training and assessment of medical specialists in Clinical (Medical) Microbiology (CM/MM) and Infectious Diseases (ID). Sources: Narrative review of developments over the past two decades and related policy documents and scientific literature. Content: Responsibility for curricula and examinations lies with the European Union of Medical Specialists (UEMS). The ID Section of UEMS was inaugurated in 1997 and the MM Section separated from Laboratory Medicine in 2008. The sections collaborate closely with each other and the European Society of Clinical Microbiology and Infectious Diseases (ESCMID). Updated European Training Requirements (ETR) were approved for MM in 2017 and ID in 2018. These comprehensive curricula outline the framework for delivery of specialist training and quality control for trainers and training programmes, emphasizing the need for documented, regular formative reviews of progress of trainees. Competencies to be achieved include both specialty-related and generic knowledge, skills and professional behaviours. The indicative length of training is typically 5 years; a year of clinical training is mandated for CM/MM trainees and 6 months of microbiology laboratory training for ID trainees. Each Section is developing examinations using multiple choice questions to test the knowledge base defined in their ETR, to be delivered in 2022 following pilot examinations in 2021. Implications: The revised ETRs and European examinations for medical specialists in CM/MM and ID provide benchmarks for national authorities to adapt or adopt locally. Through harmonization of postgraduate training and assessment, they support the promotion and recognition of high standards of clinical practice and hence improved care for patients throughout Europe, and improved mobility of trainees and specialists. Nick J. Beeching, Clin Microbiol Infect 2021;27:1581 (c) 2021 The Author(s). Published by Elsevier Ltd on behalf of European Society of Clinical Microbiology and Infectious Diseases. This is an open access article under the CC BY license (http://creativecommons. org/licenses/by/4.0/)
In support of rare relict similar to 3700 Ma stromatolites from Isua (Greenland)
No full textThis work was supported by Australian Research Council grant DP170100715. Levi Beeching, CT lab, ANU is thanked for generating the XCT images
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