781 research outputs found
IRDC G030.88+00.13: A Tale of Two Massive Clumps
Massive stars (M \gsim 10 \msun) form from collapse of parsec-scale
molecular clumps. How molecular clumps fragment to give rise to massive stars
in a cluster with a distribution of masses is unclear. We search for cold cores
that may lead to future formation of massive stars in a massive (
\msun), low luminosity ( \lsun) infrared dark cloud (IRDC)
G030.88+00.13. The \nh3 data from VLA and GBT reveal that the extinction
feature seen in the infrared consists of two distinctive clumps along the same
line of sight: The C1 clump at 97 \kms-1 coincides with the extinction in the
Spitzer 8 and 24 m. Therefore, it is responsible for the majority of the
IRDC. The C2 clump at 107 \kms-1 is more compact and has a peak temperature of
45 K. Compact dust cores and \h2O masers revealed in the SMA and VLA
observations are mostly associated with C2, and none is within the IRDC in C1.
The luminosity indicates that neither the C1 nor C2 clump has yet to form
massive protostars. But C1 might be at a precluster forming stage. The
simulated observations rule out 0.1pc cold cores with masses above 8 \msun\
within the IRDC. The core masses in C1 and C2, and those in high-mass
protostellar objects suggest an evolutionary trend that the mass of cold cores
increases over time. Based on our findings, we propose an empirical picture of
massive star formation that protostellar cores and the embedded protostars
undergo simultaneous mass growth during the protostellar evolution.Comment: 29 pages, 7 figures. Accepted to Astrophysical Journa
Hierarchical fragmentation and differential star formation in the Galactic "Snake": infrared dark cloud G11.11-0.12
We present Submillimeter Array (SMA) 0.88 and 1.3 mm broad band
observations, and the Jansky Very Large Array (VLA) observations in
up to , and maser lines toward
the two most massive molecular clumps in infrared dark cloud (IRDC)
G11.11-0.12. Sensitive high-resolution images reveal hierarchical fragmentation
in dense molecular gas from the pc clump scale down to pc
condensation scale. At each scale, the mass of the fragments is orders of
magnitude larger than the Jeans mass. This is common to all four IRDC clumps we
studied, suggesting that turbulence plays an important role in the early stages
of clustered star formation. Masers, shock heated gas, and outflows
indicate intense ongoing star formation in some cores while no such signatures
are found in others. Furthermore, chemical differentiation may reflect the
difference in evolutionary stages among these star formation seeds. We find
ortho/para ratios of , , and
associated with three outflows, and the ratio tends to increase along the
outflows downstream. Our combined SMA and VLA observations of several IRDC
clumps present the most in depth view so far of the early stages prior to the
hot core phase, revealing snapshots of physical and chemical properties at
various stages along an apparent evolutionary sequence.Comment: 21 pages, 11 figures, 8 tables, accepted to MNRAS; this version
includes minor typo corrections from proo
Disparities in Use of Human Epidermal Growth Hormone Receptor 2âTargeted Therapy for Early-Stage Breast Cancer
Trastuzumab is a key component of adjuvant therapy for stage I to III human epidermal growth factor receptor 2 (HER2)âpositive breast cancer. The rates and patterns of trastuzumab use have never been described in a population-based sample. The recent addition of HER2 information to the SEER-Medicare database offers an opportunity to examine patterns of trastuzumab use and to evaluate possible disparities in receipt of trastuzumab
Hierarchical Fragmentation and Jet-like Outflows in IRDC G28.34+0.06, a Growing Massive Protostar Cluster
We present Submillimeter Array (SMA) \lambda = 0.88mm observations of an
infrared dark cloud (IRDC) G28.34+0.06. Located in the quiescent southern part
of the G28.34 cloud, the region of interest is a massive (\,\msun)
molecular clump P1 with a luminosity of \lsun, where our previous
SMA observations at 1.3mm have revealed a string of five dust cores of 22-64
\msun\ along the 1 pc IR-dark filament. The cores are well aligned at a
position angle of 48 degrees and regularly spaced at an average projected
separation of 0.16 pc. The new high-resolution, high-sensitivity 0.88\,mm image
further resolves the five cores into ten compact condensations of 1.4-10.6
\msun, with sizes a few thousands AU. The spatial structure at clump (
pc) and core ( pc) scales indicates a hierarchical fragmentation.
While the clump fragmentation is consistent with a cylindrical collapse, the
observed fragment masses are much larger than the expected thermal Jeans
masses. All the cores are driving CO(3-2) outflows up to 38 km/s, majority of
which are bipolar, jet-like outflows. The moderate luminosity of the P1 clump
sets a limit on the mass of protostars of 3-7 \msun. Because of the large
reservoir of dense molecular gas in the immediate medium and ongoing accretion
as evident by the jet-like outflows, we speculate that P1 will grow and
eventually form a massive star cluster. This study provides a first glimpse of
massive, clustered star formation that currently undergoes through an
intermediate-mass stage.Comment: 24 pages, 4 figures, 4 tables, accepted to Ap
Interpreting population reach of a large, successful physical activity trial delivered through primary care.
Abstract
Background
Failure to include socio-economically deprived or ethnic minority groups in physical activity (PA) trials may limit representativeness and could lead to implementation of interventions that then increase health inequalities. Randomised intervention trials often have low recruitment rates and rarely assess recruitment bias. A previous trial by the same team using similar methods recruited 30% of the eligible population but was in an affluent setting with few non-white residents and was limited to those over 60 years of age.
Methods
PACE-UP is a large, effective, population-based walking trial in inactive 45-75 year-olds that recruited through seven London general practices. Anonymised practice demographic data were available for all those invited, enabling investigation of inequalities in trial recruitment. Non-participants were invited to complete a questionnaire.
Results
From 10,927 postal invitations, 1150 (10.5%) completed baseline assessment. Participation rate ratios (95% CI), adjusted for age and gender as appropriate, were lower in men 0.59 (0.52, 0.67) than women, in those under 55 compared with those â„65, 0.60 (0.51, 0.71), in the most deprived quintile compared with the least deprived 0.52 (0.39, 0.70) and in Asian individuals compared with whites 0.62 (0.50, 0.76). Black individuals were equally likely to participate as white individuals. Participation was also associated with having a co-morbidity or some degree of health limitation. The most common reasons for non-participation were considering themselves as being too active or lack of time.
Conclusions
Conducting the trial in this diverse setting reduced overall response, with lower response in socio-economically deprived and Asian sub-groups. Trials with greater reach are likely to be more expensive in terms of recruitment and gains in generalizability need to be balanced with greater costs. Differential uptake of successful trial interventions may increase inequalities in PA levels and should be monitored
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Individual Differences in Correspondence Bias: Measurement, Consequences, and Correction of Biased Interpersonal Attributions
Across consequential attributions of attitudes, ability, emotions, and morality, people make correspondent inferences. People infer stable personality characteristics from othersâ behavior, even when that behavior is caused by situational factors. We examined the structure of correspondent inferences and report the development and validation of an instrument measuring individual differences in this correspondence bias (a Neglect of External Demands scale, or âNEDâ). The NED is internally consistent and distinct from scales and measures of intelligence, cognitive ability, cognitive reflection, general decision making ability, preference for control, and attributional style. Individual differences in correspondence bias predict blaming people for harmful accidents, believing coerced confessions, correcting for job and task difficulty when making performance evaluations and incentive-compatible personnel selections, and separating market and fund performance when making incentive-compatible investments. Fortunately, the tendency to commit correspondence bias can be reduced. Making situational information easier to process debiases those most prone to correspondence bias
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Bias Blind Spot: Structure, Measurement, and Consequences
People exhibit a bias blind spot: they are less likely to detect bias in themselves than in others. We report the development and validation of an instrument to measure individual differences in the propensity to exhibit the bias blind spot that is unidimensional, internally consistent, has high test-retest reliability, and is discriminated from measures of intelligence, decision making ability, and personality traits related to self-esteem, self-enhancement, and self-presentation. The scale is predictive of the extent to which people judge their abilities to be better-than-average for easy tasks and worse-than-average for difficult tasks, ignore the advice of others, and are responsive to an intervention designed to mitigate a different judgmental bias. These results suggest that the bias blind spot is a distinct metabias resulting from naĂŻve realism rather than other forms of egocentric cognition, and has unique effects on judgment and behavior
Key features of palliative care service delivery to Indigenous peoples in Australia, New Zealand, Canada and the United States: A comprehensive review
Background: Indigenous peoples in developed countries have reduced life expectancies, particularly from chronic diseases. The lack of access to and take up of palliative care services of Indigenous peoples is an ongoing concern.
Objectives: To examine and learn from published studies on provision of culturally safe palliative care service delivery to Indigenous people in Australia, New Zealand (NZ), Canada and the United States of America (USA); and to compare Indigenous peoplesâ preferences, needs, opportunities and barriers to palliative care.
Methods: A comprehensive search of multiple databases was undertaken. Articles were included if they were published in English from 2000 onwards and related to palliative care service delivery for Indigenous populations; papers could use quantitative or qualitative approaches. Common themes were identified using thematic synthesis. Studies were evaluated using Dalyâs hierarchy of evidence-for-practice in qualitative research.
Results: Of 522 articles screened, 39 were eligible for inclusion. Despite diversity in Indigenous peoplesâ experiences across countries, some commonalities were noted in the preferences for palliative care of Indigenous people: to die close to or at home; involvement of family; and the integration of cultural practices. Barriers identified included inaccessibility, affordability, lack of awareness of services, perceptions of palliative care, and inappropriate services. Identified models attempted to address these gaps by adopting the following strategies: community engagement and ownership; flexibility in approach; continuing education and training; a whole-of-service approach; and local partnerships among multiple agencies. Better engagement with Indigenous clients, an increase in number of palliative care patients, improved outcomes, and understanding about palliative care by patients and their families were identified as positive achievements.
Conclusions: The results provide a comprehensive overview of identified effective practices with regards to palliative care delivered to Indigenous populations to guide future program developments in this field. Further research is required to explore the palliative care needs and experiences of Indigenous people living in urban areas
The perceived meaning of a (w)holistic view among general practitioners and district nurses in Swedish primary care: a qualitative study
BACKGROUND: The definition of primary care varies between countries. Swedish primary care has developed from a philosophic viewpoint based on quality, accessibility, continuity, co-operation and a holistic view. The meaning of holism in international literature differs between medicine and nursing. The question is, if the difference is due to different educational traditions. Due to the uncertainties in defining holism and a holistic view we wished to study, in depth, how holism is perceived by doctors and nurses in their clinical work. Thus, the aim was to explore the perceived meaning of a holistic view among general practitioners (GPs) and district nurses (DNs). METHODS: Seven focus group interviews with a purposive sample of 22 GPs and 20 nurses working in primary care in two Swedish county councils were conducted. The interviews were transcribed verbatim and analysed using qualitative content analysis. RESULTS: The analysis resulted in three categories, attitude, knowledge, and circumstances, with two, two and four subcategories respectively. A professional attitude involves recognising the whole person; not only fragments of a person with a disease. Factual knowledge is acquired through special training and long professional experience. Tacit knowledge is about feelings and social competence. Circumstances can either be barriers or facilitators. A holistic view is a strong motivator and as such it is a facilitator. The way primary care is organised can be either a barrier or a facilitator and could influence the use of a holistic approach. Defined geographical districts and care teams facilitate a holistic view with house calls being essential, particularly for nurses. In preventive work and palliative care, a holistic view was stated to be specifically important. Consultations and communication with the patient were seen as important tools. CONCLUSION: 'Holistic view' is multidimensional, well implemented and very much alive among both GPs and DNs. The word holistic should really be spelt 'wholistic' to avoid confusion with complementary and alternative medicine. It was obvious that our participants were able to verbalise the meaning of a 'wholistic' view through narratives about their clinical, every day work. The possibility to implement a 'wholistic' perspective in their work with patients offers a strong motivation for GPs and DNs
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