587 research outputs found
Early Integrators and the Passive Majority: An evaluation study of a large web-based bibliographic reference database
An evaluation is reported of user responses to zetoc, a service that provides access to the British Library electronic table of contents database and an email alerting service. Two questionnaire surveys and an interview programme gave data on over 800 users. The results show that about 17% are active users who are achieving a personal information management routine by integrating zetoc with other services (the early integrators). The other 83%, the `passive majority', make limited use of zetoc and do not achieve integration with other services. The interviews reveal that some of this group have a stable but restricted usage routine that limits information overload. The usage by others is less controlled and they make little use of the information they receive. The paper examines the impact of enhancements to the zetoc service to support integration and it discusses the barriers that prevent many users exploiting the potential of services available to them
Natural history museums as provocateurs for dialogue and debate
Interpretation in natural history museums is generally conservative with methods of collections interpretation barely changed since the first natural history museums were founded. For all the changes undertaken by museums in the last 20 years, sector leaders such as the American Museum of Natural History, the Natural History Museum, London, the National Museum, Prague, Museum fĂŒ r Naturkunde, Berlin and the MusĂ©um national d'Histoire naturelle, Paris still operate by connecting objects with facts about their biology. The recent relocation of the Grant Museum of Zoology at University College London has offered the opportunity for the museum to become a space for dialogue and experimentation. The museum, in collaboration with the university, has developed 'social interpretation' designed to engage visitors with controversial questions in life sciences and museum practice. Visitor responses are recorded and used as the basis to plan future work. The paper explores how this form of engagement with visitors might allow natural history museums to add to established methods of interpretation, and Ă in a form of co-production with their visitors Ă challenge attitudes to scientific knowledge and its development. Thus, the way natural history museums function as sources of knowledge for the public and the 'front line' of biological engagement is potentially changed, based on the responses of museum visitors
Accumulation of muscle ankyrin repeat protein transcript reveals local activation of primary myotube endcompartments during muscle morphogenesis
The characteristic shapes and positions of each individual body muscle are established during the process of muscle morphogenesis in response to patterning information from the surrounding mesenchyme. Throughout muscle morphogenesis, primary myotubes are arranged in small parallel bundles, each myotube spanning the forming muscles from end to end. This unique arrangement potentially assigns a crucial role to primary myotube end regions for muscle morphogenesis. We have cloned muscle ankyrin repeat protein (MARP) as a gene induced in adult rat skeletal muscle by denervation. MARP is the rodent homologue of human C-193 (Chu, W., D.K. Burns, R.A. Swerick, and D.H. Presky. 1995. J. Biol. Chem. 270:10236-10245) and is identical to rat cardiac ankyrin repeat protein. (Zou, Y., S. Evans, J. Chen, H.-C. Kuo, R.P. Harvey, and K.R. Chien. 1997. Development. 124:793-804). In denervated muscle fibers, MARP transcript accumulated in a unique perisynaptic pattern. MARP was also expressed in large blood vessels and in cardiac muscle, where it was further induced by cardiac hypertrophy. During embryonic development, MARP was expressed in forming skeletal muscle. In situ hybridization analysis in mouse embryos revealed that MARP transcript exclusively accumulates at the end regions of primary myotubes during muscle morphogenesis. This closely coincided with the expression of thrombospondin-4 in adjacent prospective tendon mesenchyme, suggesting that these two compartments may constitute a functional unit involved in muscle morphogenesis. Transfection experiments established that MARP protein accumulates in the nucleus and that the levels of both MARP mRNA and protein are controlled by rapid degradation mechanisms characteristic of regulatory early response genes. The results establish the existence of novel regulatory muscle fiber subcompartments associated with muscle morphogenesis and denervation and suggest that MARP may be a crucial nuclear cofactor in local signaling pathways from prospective tendon mesenchyme to forming muscle and from activated muscle interstitial cells to denervated muscle fibers
Going places
Journeys. We all make them. Often they take us to exotic places. Sometimes they take us even further. They might take us through time. Or they might take us into a new way of life. There are times too, when we go all over the world and back again only to find that home is, after all, where itâs all happening.
This book contains stories about many different types of journey. We hope you will enjoy travelling into it and finding a world that suits you
Low Resolution Spectral Templates For AGNs and Galaxies From 0.03 -- 30 microns
We present a set of low resolution empirical SED templates for AGNs and
galaxies in the wavelength range from 0.03 to 30 microns based on the
multi-wavelength photometric observations of the NOAO Deep-Wide Field Survey
Bootes field and the spectroscopic observations of the AGN and Galaxy Evolution
Survey. Our training sample is comprised of 14448 galaxies in the redshift
range 0<~z<~1 and 5347 likely AGNs in the range 0<~z<~5.58. We use our
templates to determine photometric redshifts for galaxies and AGNs. While they
are relatively accurate for galaxies, their accuracies for AGNs are a strong
function of the luminosity ratio between the AGN and galaxy components.
Somewhat surprisingly, the relative luminosities of the AGN and its host are
well determined even when the photometric redshift is significantly in error.
We also use our templates to study the mid-IR AGN selection criteria developed
by Stern et al.(2005) and Lacy et al.(2004). We find that the Stern et
al.(2005) criteria suffers from significant incompleteness when there is a
strong host galaxy component and at z =~ 4.5, when the broad Halpha emission
line is redshifted into the [3.6] band, but that it is little contaminated by
low and intermediate redshift galaxies. The Lacy et al.(2004) criterion is not
affected by incompleteness at z =~ 4.5 and is somewhat less affected by strong
galaxy host components, but is heavily contaminated by low redshift star
forming galaxies. Finally, we use our templates to predict the color-color
distribution of sources in the upcoming WISE mission and define a color
criterion to select AGNs analogous to those developed for IRAC photometry. We
estimate that in between 640,000 and 1,700,000 AGNs will be identified by these
criteria, but will have serious completeness problems for z >~ 3.4.Comment: Accepted for publication in The Astrophysical Journal. 26 text pages
+ 3 tables + 20 figures, modified to include comments made by the referee.
Fortran codes, templates and electronic tables available at
http://www.astronomy.ohio-state.edu/~rjassef/lrt
Who should be prioritized for renal transplantation?: Analysis of key stakeholder preferences using discrete choice experiments
Background
Policies for allocating deceased donor kidneys have recently shifted from allocation based on Human Leucocyte Antigen (HLA) tissue matching in the UK and USA. Newer allocation algorithms incorporate waiting time as a primary factor, and in the UK, young adults are also favoured. However, there is little contemporary UK research on the views of stakeholders in the transplant process to inform future allocation policy. This research project aimed to address this issue.
Methods
Discrete Choice Experiment (DCE) questionnaires were used to establish priorities for kidney transplantation among different stakeholder groups in the UK. Questionnaires were targeted at patients, carers, donors / relatives of deceased donors, and healthcare professionals. Attributes considered included: waiting time; donor-recipient HLA match; whether a recipient had dependents; diseases affecting life expectancy; and diseases affecting quality of life.
Results
Responses were obtained from 908 patients (including 98 ethnic minorities); 41 carers; 48 donors / relatives of deceased donors; and 113 healthcare professionals. The patient group demonstrated statistically different preferences for every attribute (i.e. significantly different from zero) so implying that changes in given attributes affected preferences, except when prioritizing those with no rather than moderate diseases affecting quality of life. The attributes valued highly related to waiting time, tissue match, prioritizing those with dependents, and prioritizing those with moderate rather than severe diseases affecting life expectancy. Some preferences differed between healthcare professionals and patients, and ethnic minority and non-ethnic minority patients. Only non-ethnic minority patients and healthcare professionals clearly prioritized those with better tissue matches.
Conclusions
Our econometric results are broadly supportive of the 2006 shift in UK transplant policy which emphasized prioritizing the young and long waiters. However, our findings suggest the need for a further review in the light of observed differences in preferences amongst ethnic minorities, and also because those with dependents may be a further priority.</p
On the interaction of mesoscopic quantum systems with gravity
We review the different aspects of the interaction of mesoscopic quantum
systems with gravitational fields. We first discuss briefly the foundations of
general relativity and quantum mechanics. Then, we consider the
non-relativistic expansions of the Klein-Gordon and Dirac equations in the
post-Newtonian approximation. After a short overview of classical gravitational
waves, we discuss two proposed interaction mechanisms: (i) the use of quantum
fluids as generator and/or detector of gravitational waves in the laboratory,
and (ii) the inclusion of gravitomagnetic fields in the study of the properties
of rotating superconductors. The foundations of the proposed experiments are
explained and evaluated.Comment: 27 pages, study for ESA: typos corrected, references and
clarifications added. To appear in Annalen der Physi
Multivariable model to predict an ACTH stimulation test to diagnose adrenal insufficiency using previous test results
Context
The adrenocorticotropin hormone stimulation test (AST) is used to diagnose adrenal insufficiency, and is often repeated in patients when monitoring recovery of the hypothalamoâpituitaryâadrenal axis.
Objective
To develop and validate a prediction model that uses previous AST results with new baseline cortisol to predict the result of a new AST.
Methods
This was a retrospective, longitudinal cohort study in patients who had undergone at least 2 ASTs, using polynomial regression with backwards variable selection, at a Tertiary UK adult endocrinology center. Model was developed from 258 paired ASTs over 5 years in 175 adults (mean age 52.4 years, SD 16.4), then validated on data from 111 patients over 1 year (51.8, 17.5) from the same center, data collected after model development. Candidate prediction variables included previous test baseline adrenocorticotropin hormone (ACTH), previous test baseline and 30-minute cortisol, days between tests, and new baseline ACTH and cortisol used with calculated cortisol/ACTH ratios to assess 8 candidate predictors. The main outcome measure was a new test cortisol measured 30 minutes after Synacthen administration.
Results
Using 258 sequential ASTs from 175 patients for model development and 111 patient tests for model validation, previous baseline cortisol, previous 30-minute cortisol and new baseline cortisol were superior at predicting new 30-minute cortisol (R2 = 0.71 [0.49-0.93], area under the curve [AUC] = 0.97 [0.94-1.0]) than new baseline cortisol alone (R2 = 0.53 [0.22-0.84], AUC = 0.88 [0.81-0.95]).
Conclusion
Results of a previous AST can be objectively combined with new early-morning cortisol to predict the results of a new AST better than new early-morning cortisol alone. An online calculator is available at https://endocrinology.shinyapps.io/sheffield_sst_calculator/ for external validation
The Allen Telescope Array Pi GHz Sky Survey I. Survey Description and Static Catalog Results for the Bootes Field
The Pi GHz Sky Survey (PiGSS) is a key project of the Allen Telescope Array.
PiGSS is a 3.1 GHz survey of radio continuum emission in the extragalactic sky
with an emphasis on synoptic observations that measure the static and
time-variable properties of the sky. During the 2.5-year campaign, PiGSS will
twice observe ~250,000 radio sources in the 10,000 deg^2 region of the sky with
b > 30 deg to an rms sensitivity of ~1 mJy. Additionally, sub-regions of the
sky will be observed multiple times to characterize variability on time scales
of days to years. We present here observations of a 10 deg^2 region in the
Bootes constellation overlapping the NOAO Deep Wide Field Survey field. The
PiGSS image was constructed from 75 daily observations distributed over a
4-month period and has an rms flux density between 200 and 250 microJy. This
represents a deeper image by a factor of 4 to 8 than we will achieve over the
entire 10,000 deg^2. We provide flux densities, source sizes, and spectral
indices for the 425 sources detected in the image. We identify ~100$ new flat
spectrum radio sources; we project that when completed PiGSS will identify 10^4
flat spectrum sources. We identify one source that is a possible transient
radio source. This survey provides new limits on faint radio transients and
variables with characteristic durations of months.Comment: Accepted for publication in ApJ; revision submitted with extraneous
figure remove
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