3,377 research outputs found
Expectations and experiences of gamete donors and donor-conceived adults searching for genetics relatives using DNA linking through a voluntary register
STUDY QUESTION:
What are the experiences of donor-conceived adults and donors who are searching for a genetic link through the use of a DNA-based voluntary register service?
SUMMARY ANSWER:
Donor-conceived adults and donors held positive beliefs about their search and although some concerns in relation to finding a genetically linked relative were reported, these were not a barrier to searching.
WHAT IS KNOWN ALREADY:
Research with donor-conceived people has consistently identified their interest in learning about-and in some cases making contact with-their donor and other genetic relatives. However, donor-conceived individuals or donors rarely have the opportunity to act on these desires.
STUDY DESIGN, SIZE, AND DURATION:
A questionnaire was administered for online completion using Bristol Online Surveys. The survey was live for 3 months and responses were collected anonymously.
PARTICIPANTS/MATERIALS, SETTING, AND METHODS:
The survey was completed by 65 donor-conceived adults, 21 sperm donors and 5 oocyte donors who had registered with a DNA-based voluntary contact register in the UK. The questionnaire included socio-demographic questions, questions specifically developed for the purposes of this study and the standardized Aspects of Identity Questionnaire (AIQ).
MAIN RESULTS AND THE ROLE OF CHANCE:
Motivations for searching for genetic relatives were varied, with the most common reasons being curiosity and passing on information. Overall, participants who were already linked and those awaiting a link were positive about being linked and valued access to a DNA-based register. Collective identity (reflecting self-defining feelings of continuity and uniqueness), as assessed by the AIQ, was significantly lower for donor-conceived adults when compared with the donor groups (P 0.05) for donor-conceived adults.
LIMITATIONS, REASONS FOR CAUTION:
Participants were members of a UK DNA-based registry which is unique. It was therefore not possible to determine how representative participants were of those who did not register for the service, those in other countries or of those who do not seek information exchange or contact.
WIDER IMPLICATIONS OF THE FINDINGS:
This is the first survey exploring the experiences of donor-conceived adults and donors using a DNA-based voluntary register to seek information about and contact with genetic relatives and the first to measure aspects of identity using standardized measures. Findings provide valuable information about patterns of expectations and experiences of searching through DNA linking, identity and of having contact in the context of donor conception that will inform future research, practice and policy development
A Cone Jet-Finding Algorithm for Heavy-Ion Collisions at LHC Energies
Standard jet finding techniques used in elementary particle collisions have
not been successful in the high track density of heavy-ion collisions. This
paper describes a modified cone-type jet finding algorithm developed for the
complex environment of heavy-ion collisions. The primary modification to the
algorithm is the evaluation and subtraction of the large background energy,
arising from uncorrelated soft hadrons, in each collision. A detailed analysis
of the background energy and its event-by-event fluctuations has been performed
on simulated data, and a method developed to estimate the background energy
inside the jet cone from the measured energy outside the cone on an
event-by-event basis. The algorithm has been tested using Monte-Carlo
simulations of Pb+Pb collisions at TeV for the ALICE detector at
the LHC. The algorithm can reconstruct jets with a transverse energy of 50 GeV
and above with an energy resolution of .Comment: 13 pages, 7 figure
Quantified Morphology of HI Disks in the Universe
he upcoming new perspective of the high redshift Universe in the 21 cm line
of atomic hydrogen opens possibilities to explore topics of spiral disk
evolution, hitherto reserved for the optical regime. The growth of spiral gas
disks over Cosmic time can be explored with the new generation of radio
telescopes, notably the SKA, and its precursors, as accurately as with the
Hubble Space Telescope for stellar disks. Since the atomic hydrogen gas is the
building block of these disks, it should trace their formation accurately.
Morphology of HI disks can now equally be quantified over Cosmic time. In
studies of HST deep fields, the optical or UV morphology of high-redshift
galaxy disks have been characterized using a few quantities: concentration (C),
asymmetry (A), smoothness (S), second-order-moment (M20), the GINI coefficient
(G), and Ellipticity (E). We have applied these parameters across wavelengths
and compared them to the HI morphology over the THINGS sample. NGC 3184, an
unperturbed disk, and NGC 5194, the canonical 3:1 interaction, serve as
examples for quantified morphology. We find that morphology parameters
determined in HI are as good or better a tracer of interaction compared to
those in any other wavelength, notably in Asymmetry, Gini and M20. This opens
the possibility of using them in the parameterization pipeline for SKA
precursor catalogues to select interacting or harassed galaxies from their HI
morphology. Asymmetry, Gini and M20 may be redefined for use on data-cubes
rather than HI column density image.Comment: 6 pages, 3 figures, proceeding of the conference "Panoramic Radio
Astronomy: Wide-field 1-2 GHz research on galaxy evolution", June 02 - 05
2009, Groningen, update after small edit
Quantified HI Morphology II : Lopsidedness and Interaction in WHISP Column Density Maps
Lopsidedness of the gaseous disk of spiral galaxies is a common phenomenon in
disk morphology, profile and kinematics. Simultaneously, the asymmetry of a
galaxy's stellar disk, in combination with other morphological parameters, has
seen extensive use as an indication of recent merger or interaction in galaxy
samples. Quantified morphology of stellar spiral disks is one avenue to
determine the merger rate over much of the age of the Universe. In this paper,
we measure the quantitative morphology parameters for the HI column density
maps from the Westerbork observations of neutral Hydrogen in Irregular and
SPiral galaxies (WHISP). These are Concentration, Asymmetry, Smoothness, Gini,
M20, and one addition of our own, the Gini parameter of the second order moment
(GM). Our aim is to determine if lopsided or interacting disks can be
identified with these parameters. Our sample of 141 HI maps have all previous
classifications on their lopsidedness and interaction. We find that the
Asymmetry, M20, and our new GM parameter correlate only weakly with the
previous morphological lopsidedness quantification. These three parameters may
be used to compute a probability that an HI disk is morphologically lopsided
but not unequivocally to determine it. However, we do find that that the
question whether or not an HI disk is interacting can be settled well using
morphological parameters. Parameter cuts from the literature do not translate
from ultraviolet to HI directly but new selection criteria using combinations
of Asymmetry and M20 or Concentration and M20, work very well. We suggest that
future all-sky HI surveys may use these parameters of the column density maps
to determine the merger fraction and hence rate in the local Universe with a
high degree of accuracy.Comment: 12 pages, 5 figures, 1 table, accepted by MNRAS, appendix not
include
Looking At the Distant Universe with the MeerKAT Array (LADUMA)
The MeerKAT (64 x 13.5m dish radio interferometer) is South Africa's
precursor instrument for the Square Kilometre Array (SKA), exploring dish
design, instrumentation, and the characteristics of a Karoo desert site and is
projected to be on sky in 2016. One of two top-priority, Key Projects is a
single deep field, integrating for 5000 hours total with the aim to detect
neutral atomic hydrogen through its 21 cm line emission out to redshift unity
and beyond.
This first truly deep HI survey will help constrain fueling models for galaxy
assembly and evolution. It will measure the evolution of the cosmic neutral gas
density and its distribution over galaxies over cosmic time, explore evolution
of the gas in galaxies, measure the Tully-Fisher relation, measure OH maser
counts, and address many more topics.
Here we present the observing strategy and envisaged science case for this
unique deep field, which encompasses the Chandra Deep Field-South (and the
footprints of GOODS, GEMS and several other surveys) to produce a singular
legacy multi-wavelength data-set.Comment: 3 pages, 2 figures, to appear in the proceedings of IAU Symposium
284, "The Spectral Energy Distribution of Galaxies" (SED2011), 5-9 September
2011, Preston, UK, editors R.J. Tuffs & C.C.Popesc
Recent Results on Strangeness Production at RHIC
Due to its large acceptance, the STAR experiment has acquired a wealth of
data on strangeness production for a variety of collisions systems and
energies, from p+p to Au+Au. By using the yields and spectra, we address the
evolution of the bulk system, including strangeness enhancement and the flavour
dependence of radial and elliptic flow. Utilising the fact that we can identify
strange baryons and mesons, we investigate different hadronization mechanisms
in the intermediate and high p regions. The ratios of the particle
yields, measured to high p, are used to further investigate the range and
applicability of the previously reported anomalous baryon production. We also
study two-particle azimuthal correlations of identified particles in order to
investigate any flavour dependence of jet fragmentation in the available
p range. Data was presented for a number of different collision systems
and energies.Comment: Proceedings of SQM'06 Conference, LA, 2006 (submitted to J. Phys. G
An audit of a radiotherapy review clinic for breast cancer patients: a multi-disciplinary approach
Purpose: With the advent of multi-disciplinary team working in Oncology practice, this audit was designed to assess patient satisfaction with this approach within an on-treatment review clinic for breast cancer patients. It also aimed to look at conformity of reporting of treatment side effects between different staff groups. Patients and methods: A questionnaire was distributed to 230 radical breast cancer patients once a week after each review clinic. An oncologist and a radiographer or nurse reviewed the patients during weeks 1-4 of treatment. A review form was completed at each visit specifying any side effects noted. Results: Patients appeared satisfied with their clinic visits to both the radiographer and nurse with 84 and 85% confidence and trust in the members of staff compared to 73% with the doctor. There was disparity in the recording of side effects between non-medical and medical staff groups. Conclusion: This audit has provided good evidence to support the continuation of multi-disciplinary review clinics. A key benefit is the reduction in clinic waiting times for patients and a substantial time saving for the medics. It also supports role development for the radiographer and nurse involved. 2008 Cambridge University Press.sch_rad7pub73
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