Low-Temperature Hall Effect in Substituted Sr2RuO4

We report the results of a study of the Hall effect and magnetoresistance in single crystals of Sr2RuO4 in which Sr^(2+) has been substituted by La^(3+) (Sr(2-y)La(y)RuO(4)) or Ru^(4+) by Ti^(4+) (Sr(2)Ru(1-x)Ti(x)O(4)). For undoped Sr2RuO4, the purity is so high that the strong-field Hall coefficient can be measured for fields above 4 T. The conventional weak-field Hall coefficient as a function of doping shows a sharp jump and sign change at y ~ 0.01 that is unrelated to either a sharp change in Fermi-surface topography or a magnetic instability. The implications of these results are discussed.Comment: 5 pages, 4 figure

Geomorphological control on boulder transport and coastal erosion before, during and after an extreme extra-tropical cyclone

Extreme wave events in coastal zones are principal drivers of geomorphic change. Evidence of boulder entrainment and erosional impact during storms is increasing. However, there is currently poor time coupling between pre- and post-storm measurements of coastal boulder deposits. Importantly there are no data reporting shore platform erosion, boulder entrainment and/or boulder transport during storm events – rock coast dynamics during storm events are currently unexplored. Here, we use high-resolution (daily) field data to measure and characterise coastal boulder transport before, during and after the extreme Northeast Atlantic extra-tropical cyclone Johanna in March 2008. Forty-eight limestone fine-medium boulders (n = 46) and coarse cobbles (n = 2) were tracked daily over a 0.1 km2 intertidal area during this multi-day storm. Boulders were repeatedly entrained, transported and deposited, and in some cases broken down (n = 1) or quarried (n = 3), during the most intense days of the storm. Eighty-one percent (n = 39) of boulders were located at both the start and end of the storm. Of these, 92% were entrained where entrainment patterns were closely aligned to wave parameters. These data firmly demonstrate rock coasts are dynamic and vulnerable under storm conditions. No statistically significant relationship was found between boulder size (mass) and net transport distance. Graphical analyses suggest that boulder size limits the maximum longshore transport distance but that for the majority of boulders lying under this threshold, other factors influence transport distance. Paired analysis of 20 similar sized and shaped boulders in different morphogenic zones demonstrates that geomorphological control affects entrainment and transport distance – where net transport distances were up to 39 times less where geomorphological control was greatest. These results have important implications for understanding and for accurately measuring and modelling boulde

'A Towering Virtue of Necessity': Interdisciplinarity and the Rise of Computer Music at Vietnam-Era Stanford

Stanford, more than most American universities, transformed in the early Cold War into a research powerhouse tied to national security priorities. The budgetary and legitimacy crises that beset the military- industrial- academic research complex in the 1960s thus struck Stanford so deeply that many feared the university itself might not survive. We argue that these crises facilitated the rise of a new kind of interdisciplinarity at Stanford, as evidenced in particular by the founding of the university’s computer music center. Focusing on the “multivocal technology” of computer music, we investigate the relationships between Stanford’s broader institutional environment and the interactions among musicians, engineers, administrators, activists, and funders in order to explain the emergence of one of the most creative and profi table loci for Stanford’s contributions to industry and the arts

The Bicentennial Celebration of the Vincentians in America: An Exhibition at DePaul University\u27s John T. Richardson LIbrary, 2016

Exhibit catalog for the 2016 exhibit of the same name. To commemorate the 200th anniversary of the Congregation of the Mission\u27s work in the United States, DePaul University Library, with the assistance of DePaul’s Office of Mission and Values, presents The Bicentennial Celebration of the Vincentians in America: An Exhibition at the John T. Richardson Library. The exhibition will run from September 2016 through March 2017, and encompasses two separate installations. The first, God as Compass, Rudder, and Pilot: the Missionary as a Pioneer, details the journey the Vincentian missionaries took, from its beginnings in Rome in 1815 to the company\u27s eventual settlement at St. Mary\u27s of the Barrens in the Missouri Territory in 1818. Its sister installation is Knowledge and Salvation: the Missionary as a Man of the Enlightenment, which explores books from the library of these first American Vincentians and the influence of the Enlightenment on the missionaries. The exhibit includes books, correspondence, artifacts, and maps, and acknowledges the religious vocations and motivations of the Vincentian missionaries while contextualizing their place within the larger arena of American history.https://via.library.depaul.edu/vincentian_ebooks/1040/thumbnail.jp

Exploring a string-like landscape

We explore inflationary trajectories within randomly-generated two-dimensional potentials, considered as a toy model of the string landscape. Both the background and perturbation equations are solved numerically, the latter using the two-field formalism of Peterson and Tegmark which fully incorporates the effect of isocurvature perturbations. Sufficient inflation is a rare event, occurring for only roughly one in $10^5$ potentials. For models generating sufficient inflation, we find that the majority of runs satisfy current constraints from WMAP. The scalar spectral index is less than 1 in all runs. The tensor-to-scalar ratio is below the current limit, while typically large enough to be detected by next-generation CMB experiments and perhaps also by Planck. In many cases the inflationary consistency equation is broken by the effect of isocurvature modes.Comment: 24 pages with 8 figures incorporated, matches version accepted by JCA

Spacelike Branes

Scalar field theories with appropriate potentials in Minkowski space can have time-dependent classical solutions containing topological defects which correspond to S-branes - i.e. branes all of whose tangential dimensions are spacelike. It is argued that such S-branes arise in string theory as time-dependent solutions of the worldvolume tachyon field of an unstable D-brane or D-brane-anti-D-brane pair. Using the known coupling of the spacetime RR fields to the worldvolume tachyon it is shown that these S-branes carry a charge, defined as the integral of a RR field strength over a sphere (containing a time as well as spatial dimensions) surrounding the S-brane. This same charge is carried by SD-branes, i.e. Dirichlet branes arising from open string worldsheet conformal field theories with a Dirichlet boundary condition on the timelike dimension. The corresponding SD-brane boundary state is constructed. Supergravity solutions carrying the same charges are also found for a few cases.Comment: 23 pages, harvmac(b), no figures, v2 references added and minor changes, v4: more references adde

The intractable challenge of evaluating cattle vaccination as a control for bovine tuberculosis

Vaccination of cattle against bovine Tuberculosis (bTB) has been a long-term policy objective for countries where disease continues to persist despite costly test-and-slaughter programs. The potential use of vaccination within the European Union has been linked to a need for field evaluation of any prospective vaccine and the impact of vaccination on the rate of transmission of bTB. We calculate that estimation of the direct protection of BCG could be achieved with 100 herds, but over 500 herds would be necessary to demonstrate an economic benefit for farmers whose costs are dominated by testing and associated herd restrictions. However, the low and variable attack rate in GB herds means field trials are unlikely to be able to discern any impact of vaccination on transmission. In contrast, experimental natural transmission studies could provide robust evaluation of both the efficacy and mode of action of vaccination using as few as 200 animals

Diffusive equilibrium in thin films provides evidence of suppression of hyporheic exchange and large-scale nitrate transformation in a groundwater-fed river

The hyporheic zone of riverbed sediments has the potential to attenuate nitrate from upwelling, polluted groundwater. However, the coarse-scale (5–10 cm) measurement of nitrogen biogeochemistry in the hyporheic zone can often mask fine-scale (<1 cm) biogeochemical patterns, especially in near-surface sediments, leading to incomplete or inaccurate representation of the capacity of the hyporheic zone to transform upwelling NO3−. In this study, we utilised diffusive equilibrium in thin-films samplers to capture high resolution (cm-scale) vertical concentration profiles of NO3−, SO42−, Fe and Mn in the upper 15 cm of armoured and permeable riverbed sediments. The goal was to test whether nitrate attenuation was occurring in a sub-reach characterised by strong vertical (upwelling) water fluxes. The vertical concentration profiles obtained from diffusive equilibrium in thin-films samplers indicate considerable cm-scale variability in NO3− (4.4 ± 2.9 mg N/L), SO42− (9.9 ± 3.1 mg/l) and dissolved Fe (1.6 ± 2.1 mg/l) and Mn (0.2 ± 0.2 mg/l). However, the overall trend suggests the absence of substantial net chemical transformations and surface-subsurface water mixing in the shallow sediments of our sub-reach under baseflow conditions. The significance of this is that upwelling NO3−-rich groundwater does not appear to be attenuated in the riverbed sediments at <15 cm depth as might occur where hyporheic exchange flows deliver organic matter to the sediments for metabolic processes. It would appear that the chemical patterns observed in the shallow sediments of our sub-reach are not controlled exclusively by redox processes and/or hyporheic exchange flows. Deeper-seated groundwater fluxes and hydro-stratigraphy may be additional important drivers of chemical patterns in the shallow sediments of our study sub-reach. Copyright © 2014 John Wiley & Sons, Ltd

Saving Lives – an epic quest to promote an evidence-based approach for preventing healthcare-associated infections in the National Health Service in England

Since its inception more than half a century ago, the National Health Service has continued to transform and improve the health and wellbeing of the Nation. Now treating a million people every 36 hours, the NHS provides an unprecedented range of clinical interventions that can mend accidental damage, prevent, identify and manage or cure disease, and prolong quality life. However, hospital care and healthcare interventions are always associated with potential hazards, including the risk of acquiring an infection during care. Those patients most at risk are often the most vulnerable and chronically ill in our society and they and their families suffer needlessly because healthcare-associated infections are largely preventable. During the last decade, the Richard Wells Research Centre (RWR) in the Faculty of Health and Human Sciences at University of West London (formally Thames Valley university) has collaborated with the Department of Health and a variety of other governmental organisations and professional societies to develop an evidence-based approach to preventing healthcare-associated infections. This article describes the impact of our work and our journey in partnerships to support sustainable improvements in patient care, enhance patient safety and ultimately save lives