444 research outputs found
Is Technical Services Being Deprofessionalized? A Report of the ALCTS Role of the Professional in Academic Technical Services Discussion Group Meeting, American Library Association, Washington, D.C., June 1998
Report of the June 1998 meeting of the ALA/ALCTS Role of the Professional in Academic Technical Services Discussion Group.This meeting was focused on answering the question "Is technical services being deprofessionalized?" The speakers also presented their views on the effects that recent trends are having on libraries and the library profession. Speakers included Virginia Gillham, University Librarian at Wilfrid Laurier University in Waterloo, Ontario; Marilyn Lewis, Director of Library Technical Services for Bryan Wildenthal Library at Sul Ross State University in Alpine, Texas; and Marsha Hamilton, Head of Monograph Acquisitions at the Ohio State University Libraries
The Membership and Distance of the Open Cluster Collinder 419
The young open cluster Collinder 419 surrounds the massive O star, HD 193322,
that is itself a remarkable multiple star system containing at least four
components. Here we present a discussion of the cluster distance based upon new
spectral classifications of the brighter members, UBV photometry, and an
analysis of astrometric and photometric data from the UCAC3 and 2MASS catalogs.
We determine an average cluster reddening of E(B-V)=0.37 +- 0.05 mag and a
cluster distance of 741 +- 36 pc. The cluster probably contains some very young
stars that may include a reddened M3 III star, IRAS~20161+4035
The Hubble constant from galaxy lenses: impacts of triaxiality and model degeneracies
The Hubble constant can be constrained using the time delays between multiple
images of gravitationally lensed sources. In some notable cases, typical
lensing analyses assuming isothermal galaxy density profiles produce low values
for the Hubble constant, inconsistent with the result of the HST Key Project
(72 +- 8 km/s/Mpc). Possible systematics in the values of the Hubble constant
derived from galaxy lensing systems can result from a number of factors, e.g.
neglect of environmental effects, assumption of isothermality, or contamination
by line-of-sight structures. One additional potentially important factor is the
triaxial structure of the lensing galaxy halo; most lens models account for
halo shape simply by perturbing the projected spherical lensing potential, an
approximation that is often necessary but that is inadequate at the levels of
triaxiality predicted in the CDM paradigm. To quantify the potential error
introduced by this assumption in estimates of the Hubble parameter, we strongly
lens a distant galaxy through a sample of triaxial softened isothermal halos
and use an MCMC method to constrain the lensing halo profile and the Hubble
parameter from the resulting multiple image systems. We explore the major
degeneracies between the Hubble parameter and several parameters of the lensing
model, finding that without a way to accurately break these degeneracies
accurate estimates of the Hubble parameter are not possible. Crucially, we find
that triaxiality does not significantly bias estimates of the Hubble constant,
and offer an analytic explanation for this behaviour in the case of isothermal
profiles. Neglected triaxial halo shape cannot contribute to the low Hubble
constant values derived in a number of galaxy lens systems.Comment: Minor revisions to match version published in MNRAS. 13 pages, 11
figure
An MCMC Fitting Method for Triaxial Dark Matter Haloes
Measuring the 3D distribution of mass on galaxy cluster scales is a crucial
test of the LCDM model, providing constraints on the behaviour of dark matter.
Recent work investigating mass distributions of individual galaxy clusters
(e.g. Abell 1689) using weak and strong gravitational lensing has revealed
potential inconsistencies between the predictions of structure formation models
relating halo mass to concentration and those relationships as measured in
massive clusters. However, such analyses employ simple spherical halo models
while a growing body of work indicates that triaxial 3D halo structure is both
common and important in parameter estimates. The very strong assumptions about
the symmetry of the lensing halo implied with circular or perturbative
elliptical NFW models are not physically motivated and lead to incorrect
parameter estimates with significantly underestimated error bars. We here
introduce a Markov Chain Monte Carlo (MCMC) method to fit fully triaxial models
to weak lensing data that gives parameter and error estimates that fully
incorporate the true uncertainty present in nature. Applying the MCMC triaxial
fitting method to a population of NFW triaxial lenses drawn from the shape
distribution of structure formation simulations, we find that including
triaxiality cannot explain a population of massive, highly concentrated
clusters within the framework of LCDM, but easily explains rare cases of
apparently massive, highly concentrated, very efficient lensing clusters. Our
MCMC triaxial NFW fitting method is easily expandable to include constraints
from additional data types, and its application returns model parameters and
errors that more accurately capture the true (and limited) extent of our
knowledge of the structure of galaxy cluster lenses. (abridged)Comment: 18 pages, 15 figures. Updated to match published versio
A longitudinal multi-site evaluation of community-based partnerships: implications for researchers, funders, and communities
Abstract
Background
Innovative Models Promoting Access to Care Transformation (IMPACT) was a five-year (2013ā2018), Canadian-Australian research program that aimed to use a community-based partnership approach to transform primary health care (PHC)Ā organizational structures to improve access to appropriate care for vulnerable populations. Local Innovation Partnerships (LIPs) were developed to support the IMPACT research program, and to be ongoing structures that would continue to drive local improvements to PHC.
Methods
A longitudinal development-focused evaluation explored the overall approach to governance, relationships and processes of the LIPs in the IMPACT program. Semi-structured interviews were conducted with purposively selected participants including researchers with implementation roles and non-researchers who were members of LIPs at four time points: early in the development of the LIPs in 2014; during intervention development in 2015/2016; at the intervention implementation phase in 2017; and nearing completion of the research program in 2018. Ā A hybrid deductive-inductive thematic analysis approach was used. A Guide developed to support the program was used as the framework for designing questions and analysing data using a qualitative descriptive method initially. A visual representation was developed and refined after each round of data collection to illustrate emerging themes around governance, processes and relationship building that were demonstrated by IMPACT LIPs. After all rounds of data collection, an overarching cross-case analysis of narrative summaries of each site was conducted.
Results
Common components of the LIPs identified across all rounds of data collection related to governance structures, stakeholder relationships, collaborative processes, and contextual barriers. Ā LIPs were seen primarily as a structure to support implementation of a research project rather than an ongoing multisectoral community-based partnership.Ā LIPs had relationships with many and varied stakeholders although not necessarily in ways that reflected the intended purpose. Collaboration was valued, but multiple barriers impeded the ability of LIPs to enact real collaboration in daily operations over time. We learned that experience, history, and time matter, especially with respect to community-oriented collaborative skills, structures, and relationships.
Conclusions
This longitudinal multiple case study offers lessons and implications for researchers, funders, and potential stakeholders in community-based participatory research
A New Look at Massive Clusters: weak lensing constraints on the triaxial dark matter halos of Abell 1689, Abell 1835, & Abell 2204
Measuring the 3D distribution of mass on galaxy cluster scales is a crucial
test of the LCDM model, providing constraints on the nature of dark matter.
Recent work investigating mass distributions of individual galaxy clusters
(e.g. Abell 1689) using weak and strong gravitational lensing has revealed
potential inconsistencies between the predictions of structure formation models
relating halo mass to concentration and those relationships as measured in
massive clusters. However, such analyses employ simple spherical halo models
while a growing body of work indicates that triaxial 3D halo structure is both
common and important in parameter estimates. We recently introduced a Markov
Chain Monte Carlo (MCMC) method to fit fully triaxial models to weak lensing
data that gives parameter and error estimates that fully incorporate the true
shape uncertainty present in nature. In this paper we apply that method to weak
lensing data obtained with the ESO/MPG Wide-Field Imager for galaxy clusters
A1689, A1835, and A2204, under a range of Bayesian priors derived from theory
and from independent X-ray and strong lensing observations. For Abell 1689,
using a simple strong lensing prior we find marginalized mean parameter values
M_200 = (0.83 +- 0.16)x10^15 M_solar/h and C=12.2 +- 6.7, which are marginally
consistent with the mass-concentration relation predicted in LCDM. The large
error contours that accompany our triaxial parameter estimates more accurately
represent the true extent of our limited knowledge of the structure of galaxy
cluster lenses, and make clear the importance of combining many constraints
from other theoretical, lensing (strong, flexion), or other observational
(X-ray, SZ, dynamical) data to confidently measure cluster mass profiles.
(Abridged)Comment: 21 pages, 10 figures, accepted for publication in MNRA
Evidence-based planning and costing palliative care services for children : novel multi-method epidemiological and economic exemplar
Background:
Childrenās palliative care is a relatively new clinical specialty. Its nature is multi-dimensional and its delivery necessarily multi-professional. Numerous diverse public and not-for-profit organisations typically provide services and support. Because services are not centrally coordinated, they are provided in a manner that is inconsistent and incoherent. Since the first childrenās hospice opened in 1982, the epidemiology of life-limiting conditions has changed with more children living longer, and many requiring transfer to adult services. Very little is known about the number of children living within any given geographical locality, costs of care, or experiences of children with ongoing palliative care needs and their families. We integrated evidence, and undertook and used novel methodological epidemiological work to develop the first evidence-based and costed commissioning exemplar.
Methods:
Multi-method epidemiological and economic exemplar from a health and not-for-profit organisation perspective, to estimate numbers of children under 19 years with life-limiting conditions, cost current services, determine child/parent care preferences, and cost choice of end-of-life care at home.
Results:
The exemplar locality (North Wales) had important gaps in service provision and the clinical network. The estimated annual total cost of current childrenās palliative care was about Ā£5.5 million; average annual care cost per child was Ā£22,771 using 2007 prevalence estimates and Ā£2,437- Ā£11,045 using new 2012/13 population-based prevalence estimates. Using population-based prevalence, we estimate 2271 children with a life-limiting condition in the general exemplar population and around 501 children per year with ongoing palliative care needs in contact with hospital services. Around 24 children with a wide range of life-limiting conditions require end-of-life care per year. Choice of end-of-life care at home was requested, which is not currently universally available. We estimated a minimum (based on 1 week of end-of-life care) additional cost of Ā£336,000 per year to provide end-of-life support at home. Were end-of-life care to span 4 weeks, the total annual additional costs increases to Ā£536,500 (2010/11 prices).
Conclusions:
Findings make a significant contribution to population-based needs assessment and commissioning methodology in childrenās palliative care. Further work is needed to determine with greater precision which children in the total population require access to services and when. Half of children who died 2002-7 did not have conditions that met the globally used children's palliative care condition categories, which need revision in light of findings
Effects of Experimental Sarcocystis neurona
Sarcocystis neurona is the most common cause of Equine Protozoal Myeloencephalitis (EPM), affecting 0.5ā1% horses in the United States during their lifetimes. The objective of this study was to evaluate the equine immune responses in an experimentally induced Sarcocystis neurona infection model. Neurologic parameters were recorded prior to and throughout the 70-day study by blinded investigators. Recombinant SnSAG1 ELISA for serum and CSF were used to confirm and track disease progression. All experimentally infected horses displayed neurologic signs after infection. Neutrophils, monocytes, and lymphocytes from infected horses displayed significantly delayed apoptosis at some time points. Cell proliferation was significantly increased in S. neurona-infected horses when stimulated nonspecifically with PMA/I but significantly decreased when stimulated with S. neurona compared to controls. Collectively, our results suggest that horses experimentally infected with S. neurona manifest impaired antigen specific response to S. neurona, which could be a function of altered antigen presentation, lack of antigen recognition, or both
A Cooperative Photoactive Class-I Hybrid Polyoxometalate With BenzothiadiazoleāImidazolium Cations
An organicāinorganic hybrid species based on the WellsāDawson polyoxotungstate [P2W18O62]6ā and novel fluorescent benzothiadiazoleāimidazolium cations, [BTD-4,7-ImH]2+, has been synthesized. X-ray crystallographic analysis shows that the inorganic and organic components form a hydrogen-bonded superstructure and that the cations are revealed to be non-equivalent with varying degrees of rotation between the BTD and imidazolium rings due to competition between weak intra- and intermolecular interactions. The UVāvis diffuse reflectance spectra indicate that the hybrid has a band gap of 3.13 eV, while the solid-state fluorescence properties of the cation are quenched in the hybrid material, suggesting the existence of electron transfer between the inorganic and organic components. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies of the polyoxometalate (POM) and BTD-4,7-ImH precursors, estimated through UVāvis absorption spectroscopy and cyclic voltammetry, indicate that electron transfer from the BTD cations to the POM may occur in the excited state
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