1,047 research outputs found
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Coverage-dependent molecular tilt of carbon monoxide chemisorbed on Pt{110}: A combined LEED and DFT structural analysis
The adsorption of carbon monoxide on the Pt{110} surface at coverages of 0.5 ML and 1.0 ML was investigated
using quantitative low-energy electron diffraction (LEED IV) and density-functional theory (DFT). At 0.5
ML CO lifts the reconstruction of the clean surface but does not form an ordered overlayer. At the saturation
coverage, 1.0 ML, a well-ordered p(2Ă1) superstructure with glide line symmetry is formed. It was confirmed
that the CO molecules adsorb on top of the Pt atoms in the top-most substrate layer with the molecular
axes tilted by ±22° with respect to the surface normal in alternating directions away from the close
packed rows of Pt atoms. This is accompanied by significant lateral shifts of 0.55 Ă
away from the atop
sites in the same direction as the tilt. The top-most substrate layer relaxes inwards by â4% with respect to
the bulk-terminated atom positions, while the consecutive layers only show minor relaxations. Despite the
lack of long-range order in the 0.5 ML CO layer it was possible to determine key structural parameters by
LEED IV using only the intensities of the integer-order spots. At this coverage CO also adsorbs on atop sites
with the molecular axis closer to the surface normal (b10°). The average substrate relaxations in each
layer are similar for both coverages and consistent with DFT calculations performed for a variety of ordered
structures with coverages of 1.0 ML and 0.5 ML
Isolation, Purification, and Genomic Analysis of the Novel Bacteriophage Kradal
From the Washington University Office of Undergraduate Research Digest (WUURD), Vol. 13, 05-01-2018. Published by the Office of Undergraduate Research. Joy Zalis Kiefer, Director of Undergraduate Research and Associate Dean in the College of Arts & Sciences; Lindsey Paunovich, Editor; Helen Human, Programs Manager and Assistant Dean in the College of Arts and Sciences Mentor(s): Chris Schaffe
Detection of 21-cm, H2 and Deuterium absorption at z>3 along the line-of-sight to J1337+3152
We report the detection of 21-cm and H2 absorption lines in the same DLA
system (log N(HI)=21.36+-0.10) at zabs=3.17447 towards SDSSJ133724+315254
(z=3.174). We estimate the spin temperature of the gas to be, Ts~600 K,
intermediate between the expected values for cold and warm neutral media. This
suggests that the HI absorption originates from a mixture of different phases.
The total molecular fraction is low, f=10^-7, and H2 rotational level
populations are not in equilibrium. The average abundance of the alpha-elements
is, [S/H]=-1.45. N and Fe are found underabundant with respect to
alpha-elements by ~1.0 dex and ~0.5 dex respectively. Using photoionization
models we conclude that the gas is located more than 270 kpc away from the QSO.
While the position of 21-cm absorption line coincides with the H2 velocity
profile, their centroid are shifted by 2.7+-1.0 km/s from each other. However,
the position of the strongest metal absorption component matches the position
of the 21-cm absorption line within 0.5 km/s. From this, we constrain the
variation of the combination of fundamental constants x=alpha^2 Gp/mu, Delta
x/x=-(1.7+-1.7)x10^-6. This system is unique as we can at the same time have an
independent constrain on mu using H2 lines. However only Werner band absorption
lines are seen and the range of sensitivity coefficients is too narrow to
provide a stringent constraint: Delta mu/mu <= 4.0x10^-4. The VLT/UVES spectrum
reveals another DLA at zabs=3.16768 with log N(HI)=20.41+-0.15 and low
metallicity, [Si/H]=-2.68+-0.11. We derive log N(DI)/N(HI)=-(4.93+-0.15) in
this system. This is a factor of two smaller than the value expected from the
best fitted value of Omega_b from the WMAP 5 yr data. This confirms the
presence of astration of deuterium even at very low metallicity. [abridged]Comment: 14 pages, 11 figures, 4 tables, accepted for publication in MNRA
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Methodologies for Housing Justice Resource Guide
This Resource Guide is the outcome of a Summer Institute on Methodologies for Housing Justice convened by the Institute on Inequality and Democracy at UCLA Luskin as part of the Housing Justice in Unequal Cities Network, which is supported by the National Science Foundation (BCS 1758774). Held in Los Angeles in August 2019, the Summer Institute brought together participants from cities around the world. As is the case with the overall scope and purpose of the Housing Justice in Unequal Cities Network, it created a shared terrain of scholarship for movement-based and university-based scholars. Dissatisfied with the canonical methods that are in use in housing studies and guided by housing justice movements that are active research communities, the Summer Institute was premised on the assertion that methodology is political. Methodology is rooted in arguments about the world and involves relations of power and knowledge. The method itself â be it countermapping or peopleâs diaries â does not ensure an ethics of solidarity and a purpose of justice. Such goals require methodologies for liberation. Thus, as is evident in this Resource Guide, our endeavor foregrounds innovative methods that are being used by researchers across academia and activism and explicitly situates such methods in an orientation towards housing justice
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Higher Education and Society in Changing Times: looking back and looking forward
This is the last CHERI report. With the closure of the Centre, the tasks of researching and analysing higher education will henceforth lie with others. In the following pages, we look at some of the changes facing higher education and at the challenges they pose, both to those who work in higher education and to those who use it. The papers draw broadly on research projects and experience from within CHERI and beyond. As well as the papers prepared by CHERI researchers - John Brennan, Brenda Little, Mala Singh and Ruth Williams - the report contains papers from two of CHERIâs visiting professors - Roger Brown and Roger King. And we are particularly pleased to be able to include three contributions from a new generation of higher education researchers â Marina Elias, Manja KlemenÄiÄ and Sofia Sousa â who also bring welcome international perspectives to the report.
The sub-theme of the report is âlooking back and looking forwardâ. Over its nearly 19 years of existence, CHERI has worked with some of the leading scholars in the higher education research field. And we
remember the contributions of the likes of Maurice Kogan, Ulrich Teichler, Martin Trow, Harold Silver and many more with enormous respect and gratitude and as a reminder to ourselves and to our readers that there is a substantial international body of research and scholarship on the relationship between higher education and society which is too often forgotten or ignored in current debates and policy analysis.
In 2008, CHERI led a âForward Lookâ on higher education for the European Science Foundation and the reports from that project attempted to provide an agenda for future research in the field, research that would be highly relevant to policy-making but not constrained or limited by it. That agenda is being implemented in the subsequent âHigher Education and Social Changeâ research programme of the ESF and, we hope, elsewhere. While CHERI may not be around to see the results of that implementation, we wish it well and hope that its fruits will be of benefit to all those who use and are affected by higher education.
Although CHERI as a research centre is set to disappear, the experience and expertise that it has built up over the years remains and we hope will continue to contribute to research and policy analysis in higher education, both in the UK and far beyond
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Cannabis sativa and the endogenous cannabinoid system: therapeutic potential for appetite regulation
The herb Cannabis sativa (C. sativa) has been used in China and on the Indian subcontinent for thousands of years as a medicine. However, since it was brought to the UK and then the rest of the western world in the late 19th century, its use has been a source of controversy. Indeed, its psychotropic side effects are well reported but only relatively recently has scientific endeavour begun to find valuable uses for either the whole plant or its individual components. Here, we discuss evidence describing the endocannabinoid system, its endogenous and exogenous ligands and their varied effects on feeding cycles and meal patterns. Furthermore we also critically consider the mounting evidence which suggests nonâtetrahydrocannabinol phytocannabinoids play a vital role in C. sativaâinduced feeding pattern changes. Indeed, given the wide range of phytocannabinoids present in C. sativa and their equally wide range of intraâ, interâ and extraâcellular mechanisms of action, we demonstrate that nonâÎ9tetrahydrocannabinol phytocannabinoids retain an important and, as yet, untapped clinical potential
Governments, decentralisation, and the risk of electoral defeat
<p>In the last three decades several countries around the world have transferred authority from their national to their regional governments. However, not all their regions have been empowered to the same degree and important differences can be observed between and within countries. Why do some regions obtain more power than others? Current literature argues that variation in the redistribution of power and resources between regions is introduced by demand. Yet these explanations are conditional on the presence of strong regionalist parties or territorial cleavages. This article proposes instead a theory that links the governmentâs risk of future electoral defeat with heterogeneous decentralisation, and tests its effects using data from 15 European countries and 141 regions. The results provide evidence that parties in government protect themselves against the risk of electoral defeat by selectively targeting decentralisation towards regions in which they are politically strong. The findings challenge previous research that overestimates the importance of regionalist parties while overlooking differences between regions.</p
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