114,308 research outputs found
Cleaning up the catalogue
The London School of Economics wanted to remove cataloguing inconsistencies but the scale of the task was huge, and outsourcing to a specialist bibliographic services company proved only a partial solution. Helen Williams explains why manual and automated processes were needed
NASA's Zero-g aircraft operations
NASA's Zero-g aircraft, operated by the Johnson Space Center, provides the unique weightless or zero-g environment of space flight for hardware development and test and astronaut training purposes. The program, which began in 1959, uses a slightly modified Boeing KC-135A aircraft, flying a parabolic trajectory, to produce weightless periods of 20 to 25 seconds. The program has supported the Mercury, Gemini, Apollo, Skylab, Apollo-Soyuz and Shuttle programs as well as a number of unmanned space operations. Typical experiments for flight in the aircraft have included materials processing experiments, welding, fluid manipulation, cryogenics, propellant tankage, satellite deployment dynamics, planetary sciences research, crew training with weightless indoctrination, space suits, tethers, etc., and medical studies including vestibular research. The facility is available to microgravity research organizations on a cost-reimbursable basis, providing a large, hands-on test area for diagnostic and support equipment for the Principal Investigators and providing an iterative-type design approach to microgravity experiment development. The facility allows concepts to be proven and baseline experimentation to be accomplished relatively inexpensively prior to committing to the large expense of a space flight
Embryo futures and stem cell research: The management of informed uncertainty
This article is available open access and is distributed under a Creative Commons license (http://creativecommons.org/licenses/by/3.0/). Copyright @ 2011 The Authors.In the social worlds of assisted conception and stem cell science, uncertainties proliferate and particular framings of the future may be highly strategic. In this article we explore meanings and articulations of the future using data from our study of ethical and social issues implicated by the donation of embryos to human embryonic stem cell research in three linked assisted conception units and stem cell laboratories in the UK. Framings of the future in this field inform the professional management of uncertainty and we explore some of the tensions this involves in practice. The bifurcation of choices for donating embryos into accepting informed uncertainty or not donating at all was identified through the research process of interviews and ethics discussion groups. Professional staff accounts in this study contained moral orientations that valued ideas such as engendering patient trust by offering full information, the sense of collective ownership of the National Heath Service and publicly funded science and ideas for how donors might be able to give restricted consent as a third option.The Wellcome Trus
Recall of physical activity advice was associated with higher levels of physical activity in colorectal cancer patients.
The present study tested the hypothesis that recall of receiving physical activity (PA) advice would be associated with higher levels of PA in patients with a diagnosis of colorectal cancer (CRC)
Donation of 'spare' fresh or frozen embryos to research: Who decides that an embryo is 'spare' and how can we enhance the quality and protect the validity of consent?
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited - Copyright @ The Author 2012.This paper analyses elements of the legal process of consent to the donation of āspareā embryos to research, including stem-cell research, and makes a recommendation intended to enhance the quality of that process, including on occasion by guarding against the invalidity of such consent. This is important in its own right and also so as to maximise the reproductive treatment options of couples engaged in in vitro fertilisation (IVF) treatment and to avoid possible harms to them. In Part 1, with reference to qualitative data from three UK IVF clinics, we explore the often delicate and contingent nature of what comes to be, for legal purposes, a āspareā embryo. The way in which an embryo becomes āspareā, with its implications for the process of consent to donation to research, is not addressed in the relevant reports relating to or codes of practice governing the donation of embryos to research, which assume an unproblematic notion of the āspareā embryo. Significantly, our analysis demonstrates that there is an important and previously unrecognised first stage in the donation of a āspareā embryo to research, namely: consent to an embryo being āspareā and so, at the same time, to its disuse in treatment. This is not explicitly covered by the Human Fertilisation and Embryology (HFE) Act 1990, as amended by the HFE Act 2008. Having identified this important initial stage in the process of consent to the donation of a āspareā embryo to research in conclusion to Part 1, in Part 2 we analyse the idea of consent to an embryo's disuse in treatment on the basis that it is āspareā with reference to the legal elements of consent, namely information as to nature and purpose, capacity, and voluntariness. We argue that there are in fact three related consent processes in play, of which the principal one concerns consent to an embryo's disuse in treatment. If the quality of this first consent is compromised, in turn this will impact on the quality of the consent to the donation of that āspareā embryo to research, followed by the quality of consent to future cycles of assisted reproduction treatment in the event that these are needed as a result of a donation decision. The analysis overall is of central relevance to the debate as to whether, and if so when, it should be permissible to request the donation of fresh embryos for research, as opposed to those that have been frozen and, for instance, have reached the end of their statutory storage term. This has a particular bearing on the donation of embryos to stem-cell research since there is a debate as to whether fresh embryos are most useful for this.This work is funded by the Wellcome Trust Biomedical Ethics Programme, Project Grant No 081414
Three-body recombination in a three-state Fermi gas with widely tunable interactions
We investigate the stability of a three spin state mixture of ultracold
fermionic Li atoms over a range of magnetic fields encompassing three
Feshbach resonances. For most field values, we attribute decay of the atomic
population to three-body processes involving one atom from each spin state and
find that the three-body loss coefficient varies by over four orders of
magnitude. We observe high stability when at least two of the three scattering
lengths are small, rapid loss near the Feshbach resonances, and two unexpected
resonant loss features. At our highest fields, where all pairwise scattering
lengths are approaching , we measure a three-body loss
coefficient and a trend
toward lower decay rates for higher fields indicating that future studies of
color superfluidity and trion formation in a SU(3) symmetric Fermi gas may be
feasible
Corrosion resistant coating
A method of coating a substrate with an amorphous metal is described. A solid piece of the metal is bombarded with ions of an inert gas in the presence of a magnetic field to provide a vapor of the metal which is deposited on the substrate at a sufficiently low gas pressure so that there is formed on the substrate a thin, uniformly thick, essentially pinhole-free film of the metal
Momentum distribution and ordering in mixtures of ultracold light and heavy fermionic atoms
The momentum distribution is one of the most important quantities which
provides information about interactions in many-body systems. At the same time
it is a quantity that can easily be accessed in experiments on ultracold atoms.
In this paper, we consider mixtures of light and heavy fermionic atoms in an
optical lattice described effectively by the Falicov-Kimball model. Using a
Monte Carlo method, we study how different ordered density-wave phases can be
detected by measurement of the momentum distribution of the light atoms. We
also demonstrate that ordered phases can be seen in Bragg scattering
experiments. Our results indicate that the main factor that determines the
momentum distribution of the light atoms is the trap confinement. On the other
hand, the pattern formed by the heavy atoms seen in the Bragg scattering
experiments is very sensitive to the temperature and possibly can be used in
low-temperature thermometry.Comment: 10 pages, 11 figure
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