3,939 research outputs found
OH spectral evolution of oxygen-rich late-type stars
We investigated the main-line spectral evolution with shell thickness of
oxygen rich AGB stars. The study is based on a sample of 30 sources distributed
along the IRAS colour-colour diagram. The sources were chosen to trace the
Miras with thick shells and the whole range of OH/IR stars. The Miras exhibit a
1665 MHz emission strength comparable to that at 1667 MHz. Even though the
Miras of the study have quite thick shells, their spectral characteristics in
both main lines attest to a strong heterogeneity in their OH shell with, in
particular, the presence of significant turbulence and acceleration. The
expansion velocity has been found to be about the same at 1665 and 1667 MHz,
taking into account a possible velocity turbulence of 1-2km/s at the location
of the main-line maser emission. An increase in the intensity ratio 1667/1665
with shell thickness has been found. A plausible explanation for such a
phenomenon is that competitive gain in favour of the 1667 MHz line increases
when the shell is getting thicker. There is an evolution in the spectral
profile shape with the appearance of a substantial inter-peak signal when the
shell is getting thicker. Also, inter-peak components are found and can be as
strong as the external standard peaks when the shell is very thick. This trend
for an increase of the signal in between the two main peaks is thought to be
the result of an increase of the saturation with shell thickness. All sources
but two - a Mira and an OH/IR star from the lower part of the colour-colour
diagram - are weakly polarized. The strong polarization observed for those two
particular objects is thought to be the result of perturbations in their
shells.Comment: 19 pages, 12 figures, accepted for publication in A&
Modelling the cost-effectiveness of public awareness campaigns for the early detection of non-small-cell lung cancer
Background: Survival rates in lung cancer in England are significantly lower than in many similar countries. A range of Be Clear on
Cancer (BCOC) campaigns have been conducted targeting lung cancer and found to improve the proportion of diagnoses at the
early stage of disease. This paper considers the cost-effectiveness of such campaigns, evaluating the effect of both the regional
and national BCOC campaigns on the stage distribution of non-small-cell lung cancer (NSCLC) at diagnosis.
Methods: A natural history model of NSCLC was developed using incidence data, data elicited from clinical experts and model
calibration techniques. This structure is used to consider the lifetime cost and quality-adjusted survival implications of the early
awareness campaigns. Incremental cost-effectiveness ratios (ICERs) in terms of additional costs per quality-adjusted life-years
(QALYs) gained are presented. Two scenario analyses were conducted to investigate the role of changes in the âworried-wellâ
population and the route of diagnosis that might occur as a result of the campaigns.
Results: The base-case theoretical model found the regional and national early awareness campaigns to be associated with QALY
gains of 289 and 178 QALYs and ICERs of d13 660 and d18 173 per QALY gained, respectively. The scenarios found that increases
in the âworried-wellâ population may impact the cost-effectiveness conclusions.
Conclusions: Subject to the available evidence, the analysis suggests that early awareness campaigns in lung cancer have the
potential to be cost-effective. However, significant additional research is required to address many of the limitations of this study.
In addition, the estimated natural history model presents previously unavailable estimates of the prevalence and rate of disease
progression in the undiagnosed population
Environmental barriers to sociality in an obligate eusocial sweat bee
This is the final version of the article. Available from Springer Verlag via the DOI in this record.All data generated or analysed during this study are included in this published article and its supplementary materials.Understanding the ecological and environmental contexts in which eusociality can evolve is fundamental to elucidating its evolutionary origins. A sufficiently long active season is postulated to have been a key factor facilitating the transition to eusociality. Many primitively eusocial species exhibit an annual life cycle, which is thought to preclude the expression of eusociality where the active season is too short to produce successive worker and reproductive broods. However, few studies have attempted to test this idea experimentally. We investigated environmental constraints on the expression of eusociality in the obligate primitively eusocial sweat bee Lasioglossum malachurum, by transplanting nest foundresses from the south to the far north of the United Kingdom, far beyond the natural range of L. malachurum. We show that transplanted bees can exhibit eusociality, but that the short length of the season and harsher environmental conditions could preclude its successful expression. In one year, when foundresses were transplanted only after provisioning first brood (B1) offspring, workers emerged in the north and provisioned a second brood (B2) of reproductives. In another year, when foundresses were transplanted prior to B1 being provisioned, they were just as likely to initiate nesting and provisioned just as many B1 cells as foundresses in the south. However, the life cycle was delayed by approximately 7 weeks and nests suffered 100% B1 mortality. Our results suggest that short season length together with poor weather conditions represent an environmental barrier to the evolution and expression of eusociality in sweat bees.This work formed part of a studentship (1119965) awarded to PJD funded by the Natural Environment Research Council and the University of Sussex, supervised by JF
The Sizes of OH (1720 MHz) Supernova Remnant Masers: MERLIN and VLBA Observations of IC443
MERLIN and VLBA observations of the 1720 MHz maser emission from the OH
molecule in the supernova remnant IC443 are presented. Based on MERLIN data
with a resolution of 160 mas, the deconvolved sizes of the maser sources are in
the range 90 to 180 mas (135 to 270 AU). The 12 mas resolution VLBA images show
compact cores with sizes in the range 15 to 55 mas. The maser brightness
temperatures are (2-34)x10^6 K for the MERLIN sources and (5-19)x10^8 K for the
VLBA cores, in agreement with theory. Unlike the Zeeman Stokes V profiles
observed in other OH (1720 MHz) SNR masers, single-handed circular polarization
line profiles are observed in IC443 on all angular scales from 1000 to 10 mas
resolution. For one line component, the observed line width is 0.24+/-0.07
km/s, compared to an estimated Doppler width of 0.49 km/s. This discrepancy in
line widths can be accounted for if the maser emission arises from an elongated
ellipsoidal region of masing gas.Comment: 22 pages, 4 figures, 3 tables, AASTex, accepted to Ap
The impact of prior care experience on nursing students' compassionate values and behaviours: A mixed methods study
Background: Compassion is critical to the provision of high-quality healthcare and is foregrounded internationally as an issue of contemporary concern. Paid care experience prior to nurse training has been suggested as a potential means of improving compassion, which has been characterised by the values and behaviours of care, compassion, competence, communication, courage, and commitment. There is however a dearth of evidence to support the effectiveness of prior care experience as a means of improving compassion in nursing. Objective: To explore the impact of paid prior care experience on the values and behaviours of pre-registration nursing students indicated as characterising compassionate care. Design: Longitudinal mixed methods design employing a modified concurrent triangulation strategy, comprising two work packages. Work package 1 was qualitative, and work package 2 adopted a concurrent embedded strategy with a dominant quantitative component. Research is reported in accordance with the Good Reporting of a Mixed Methods Study framework. Setting(s): Three United Kingdom universities. Participants: Pre-registration nursing students attending one of three universities, and individuals who had previously participated in a Health Education England paid prior care experience pilot. Participant numbers at time point 1 were questionnaires n = 220, telephone interviews n = 10, and focus groups n = 8. Methods: Work package 1 consisted of longitudinal semi-structured telephone interviews. Work package 2 comprised validated online questionnaires measuring emotional intelligence, compassion satisfaction and fatigue, resilience, psychological empowerment, and career commitment (as proxies of compassionate values and behaviours), and focus groups. Qualitative data were thematically analysed. Quantitative data were analysed via Analysis of Variance in SPSS v 26. Results: Qualitative findings suggest that prior care experience has both positive and negative effects on students' compassionate values and behaviours, however positive effects do not extend to qualification. No statistically significant differences were found in any of the quantitative outcome measures between participants with and without paid prior care experience. A statistically significant increase in compassion fatigue was identified in both groups of participants post-qualification. Paid prior care experience did not prevent participants from experiencing reality shock on becoming a student or on qualification. Conclusions: There is insufficient evidence of longitudinal beneficial impact to recommend paid prior care experience as an effective intervention to foster nursing students' compassionate values and behaviours. These findings do not support mandating a period of paid care experience as a prerequisite for entry into nurse education. Registration: N/A. Tweetable abstract Insufficient evidence of longitudinal beneficial impact to recommend prior care experience as an effective intervention to foster nursing student compassion @PriorCareExp @Sarah_F_
Modeling investigation of ionospheric storm effects over Millstone Hill during August 4â5, 1992
Neonatal intervention
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68335/2/10.1177_027112148300300105.pd
Knee contact forces are not altered in early knee osteoarthritis.
OBJECTIVE: This study calculated knee contact forces (KCF) and its relations with knee external knee adduction moments (KAM) and/or flexion moments (KFM) during the stance phase of gait in patients with early osteoarthritis (OA), classified based on early joint degeneration on Magnetic Resonance Imaging (MRI). We aimed at assessing if altered KCF are already present in early structural degeneration. DESIGN: Three-dimensional motion and ground reaction force data in 59 subjects with medial compartment knee OA (N=23 established OA, N=16 early OA, N=20 controls) were used as input for a musculoskeletal model. KAM and KFM, and KCF were estimated using OpenSim software. RESULTS: No significant differences were found between controls and subjects with early OA. In early OA patients, KAM significantly explained 69% of the variance associated with the first peaks KCF but only KFM contributed to the second peaks KCF. The multiple correlation, combining KAM and KFM, showed to be higher. However, only 20% of the variance of second peak KCF was explained by both moments in established OA. CONCLUSION: KCF are not increased in patients with early OA, suggesting that knee joint overload is more a consequence of further joint degeneration in more advanced stages of OA. Additionally, our results clearly show that KAM is not sufficient to predict joint loading at the end of the stance, where KFM contributes substantially to the loading, especially in early OA
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
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