516 research outputs found
Advance care planning for patients with end-stage kidney disease on dialysis: narrative review of the current evidence, and future considerations
Patients with end-stage kidney disease (ESKD) have a high symptom-burden and high rates of morbidity and mortality. Despite this, evidence has shown that this patient group does not have timely discussions to plan for deterioration and death, and at the end of life there are unmet palliative care needs. Advance care planning is a process that can help patients share their personal values and preferences for their future care and prepare for declining health. Earlier, more integrated and holistic advance care planning has the potential to improve access to care services, communication, and preparedness for future decision-making and changing circumstances. However, there are many barriers to successful implementation of advance care planning in this population. In this narrative review we discuss the current evidence for advance care planning in patients on dialysis, the data around the barriers to advance care planning implementation, and interventions that have been trialled. The review explores whether the concepts and approaches to advance care planning in this population need to be updated to encompass current and future care. It suggests that a shift from a problem-orientated approach to a goal-orientated approach may lead to better engagement, with more patient-centred and satisfying outcomes
Tense and aspect in word problems about motion: diagram, gesture, and the felt experience of time
© 2014, Mathematics Education Research Group of Australasia, Inc. Word problems about motion contain various conjugated verb forms. As students and teachers grapple with such word problems, they jointly operationalize diagrams, gestures, and language. Drawing on findings from a 3-year research project examining the social semiotics of classroom interaction, we show how teachers and students use gesture and diagram to make sense of complex verb forms in such word problems. We focus on the grammatical category of “aspect” for how it broadens the concept of verb tense. Aspect conveys duration and completion or frequency of an event. The aspect of a verb defines its temporal flow (or lack thereof) and the location of a vantage point for making sense of this durational process
The implausibility of ‘usual care’ in an open system: sedation and weaning practices in Paediatric Intensive Care Units (PICUs) in the United Kingdom (UK)
Background: The power of the randomised controlled trial depends upon its capacity to operate in a closed
system whereby the intervention is the only causal force acting upon the experimental group and absent in the
control group, permitting a valid assessment of intervention efficacy. Conversely, clinical arenas are open systems
where factors relating to context, resources, interpretation and actions of individuals will affect implementation and
effectiveness of interventions. Consequently, the comparator (usual care) can be difficult to define and variable in
multi-centre trials. Hence outcomes cannot be understood without considering usual care and factors that may
affect implementation and impact on the intervention.
Methods: Using a fieldwork approach, we describe PICU context, ‘usual’ practice in sedation and weaning from
mechanical ventilation, and factors affecting implementation prior to designing a trial involving a sedation and
ventilation weaning intervention. We collected data from 23 UK PICUs between June and November 2014 using
observation, individual and multi-disciplinary group interviews with staff.
Results: Pain and sedation practices were broadly similar in terms of drug usage and assessment tools. Sedation
protocols linking assessment to appropriate titration of sedatives and sedation holds were rarely used (9 % and 4 %
of PICUs respectively). Ventilator weaning was primarily a medical-led process with 39 % of PICUs engaging senior
nurses in the process: weaning protocols were rarely used (9 % of PICUs). Weaning methods were variably based
on clinician preference. No formal criteria or use of spontaneous breathing trials were used to test weaning
readiness. Seventeen PICUs (74 %) had prior engagement in multi-centre trials, but limited research nurse
availability. Barriers to previous trial implementation were intervention complexity, lack of belief in the evidence and
inadequate training. Facilitating factors were senior staff buy-in and dedicated research nurse provision.
Conclusions: We examined and identified contextual and organisational factors that may impact on the
implementation of our intervention. We found usual practice relating to sedation, analgesia and ventilator weaning
broadly similar, yet distinctively different from our proposed intervention, providing assurance in our ability to
evaluate intervention effects. The data will enable us to develop an implementation plan; considering these factors
we can more fully understand their impact on study outcomes
Where Do I Come From? Metaphors in Sex Education Picture Books for Young Children in China
This study examines the types of verbal, pictorial, and multimodal metaphors in the genre of sex education picture books for young children in Mainland China. Although being an educational discourse genre that is essentially concerned with transmitting scientific facts, sex education picture books employ a range of metaphors that categorize and construe the biological knowledge of human reproduction in a way that not only facilitates young children’s understanding of scientific concepts but also instills in them particular values and moralities that are socioculturally conditioned. An examination of the source domains from which the metaphors are drawn and the target domains onto which the metaphors are mapped reveals three types of metaphor, namely, personification, domestication, and cross-experience metaphors. The analysis of seven sex education picture books for pre-school children suggests that these types of metaphor are used purposefully for addressing pedagogical as well as ideological concerns in the introduction of sex-related knowledge in Mainland China
ISO observations of Hickson Compact Group 31 with the central Wolf-Rayet galaxy NGC 1741
Hickson Compact Group (HCG) 31, consisting of the Wolf-Rayet galaxy NGC 1741
and its irregular dwarf companions, was observed using the Infrared Space
Observatory. The deconvolved ISOCAM maps of the galaxies using the 7.7 micron
and 14.3 micron (LW6 and LW3) filters are presented, along with ISOPHOT
spectrometry of the central starburst region of NGC 1741 and the nucleus of
galaxy HCG 31A. Strong mid-IR emission was detected from the central burst in
NGC 1741, along with strong PAH features and a blend of features including [S
IV] at 10.5 micron. The 14.3/6.75 micron flux ratio, where the 6.75 micron flux
was synthesized from the PHT-S spectrum, and 14.3/7.7 micron flux ratios
suggest that the central burst within NGC 1741 may be moving towards the
post-starburst phase. Diagnostic tools including the ratio of the integrated
PAH luminosity to the 40 to 120 micron infrared luminosity and the far-infrared
colours reveal that despite the high surface brightness of the nucleus, the
properties of NGC 1741 can be explained in terms of a starburst and do not
require the presence of an AGN. The Tycho catalogue star TYC 04758-466-1, with
m = 11.3 and spectral type F6, was detected at 7.7 and 14.3 microns.Comment: 27 pages, 7 figures. Accepted for publication in the Astrophysical
Journa
Compassion Stress and the Qualitative Researcher
Human subjects are carefully protected in the research process. However, the same consideration is not currently being given to the qualitative researcher, even those investigating topics that are likely to elicit powerful emotions. The role of researcher’s emotional responses and the self-care strategies that, in some circumstances, are appropriate for the researcher and other research support personnel have not received the attention they deserve in qualitative research literature. Based on experience in conducting research on the topic of self-directed learning and breast cancer, and on the limited literature available, the author makes the case for the use of strategies such as counseling, peer debriefing, and journal writing as means of dealing with the potential for “compassion stress” as experienced by the researcher and other research support personnel. She also suggests that the preparation of social science researchers should include information on appropriate self-care strategies.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
Star cluster formation and evolution in Mrk 930: properties of a metal-poor starburst
We present a HST multiband analysis of the large population of star clusters
in the blue compact galaxy (BCG) Mrk 930. We have reconstructed the spectral
energy distributions of the star clusters and estimated age, mass, and
extinction for a representative sample. We observe a very young cluster
population with 70% of the systems formed less than 10 Myr ago. The peak in the
star cluster age distribution at 4 Myr is corroborated by the presence of
Wolf-Rayet spectral features, and by the observed optical and IR lines ratios
[OIII]/H_beta and [NeIII]/[NeII]. The recovered extinction in these very young
clusters shows large variations, with a decrease at older ages. It is likely
that our analysis is limited to the optically brightest objects (i.e. systems
only partially embedded in their natal cocoons). We map the extinction across
the galaxy using low-resolution spectra and the H_alpha/H_beta ratio, as
obtained from ground-based narrow band imaging. We find that the mean optical
extinction derived in the starburst regions is close to the averaged value
observed in the clusters, but locally, do not trace the more extinguished
clusters. Previous HST studies of BCGs have revealed a population of young and
extremely red super star clusters. We detect a considerable fraction of
clusters affected by a red excess also in Mrk 930. The nature of the red
excess, which turns up at near-IR wavelengths remains unknown. We compare the
cluster and the star formation history, the latter derived from the fit of
spectral population synthesis models to the spectra. We find a general
agreement between the two independently estimated quantities. Using the cluster
properties we perform a study of the host environmental properties. We find
that the cluster formation efficiency is significantly higher, suggesting a key
role of the environment for the formation of these massive objects.[Abridged]Comment: 21 pages, 16 figures, accepted for publication in MNRAS. For
high-resolution figures ask the author
Ferritins: furnishing proteins with iron
Ferritins are a superfamily of iron oxidation, storage and mineralization proteins found throughout the animal, plant, and microbial kingdoms. The majority of ferritins consist of 24 subunits that individually fold into 4-α-helix bundles and assemble in a highly symmetric manner to form an approximately spherical protein coat around a central cavity into which an iron-containing mineral can be formed. Channels through the coat at inter-subunit contact points facilitate passage of iron ions to and from the central cavity, and intrasubunit catalytic sites, called ferroxidase centers, drive Fe2+ oxidation and O2 reduction. Though the different members of the superfamily share a common structure, there is often little amino acid sequence identity between them. Even where there is a high degree of sequence identity between two ferritins there can be major differences in how the proteins handle iron. In this review we describe some of the important structural features of ferritins and their mineralized iron cores and examine in detail how three selected ferritins oxidise Fe2+ in order to explore the mechanistic variations that exist amongst ferritins. We suggest that the mechanistic differences reflect differing evolutionary pressures on amino acid sequences, and that these differing pressures are a consequence of different primary functions for different ferritins
Circulating mitochondrial DNA is an early indicator of severe illness and mortality from COVID-19
BackgroundMitochondrial DNA (MT-DNA) are intrinsically inflammatory nucleic acids released by damaged solid organs. Whether circulating cell-free MT-DNA quantitation could be used to predict the risk of poor COVID-19 outcomes remains undetermined.MethodsWe measured circulating MT-DNA levels in prospectively collected, cell-free plasma samples from 97 subjects with COVID-19 at hospital presentation. Our primary outcome was mortality. Intensive care unit (ICU) admission, intubation, vasopressor, and renal replacement therapy requirements were secondary outcomes. Multivariate regression analysis determined whether MT-DNA levels were independent of other reported COVID-19 risk factors. Receiver operating characteristic and area under the curve assessments were used to compare MT-DNA levels with established and emerging inflammatory markers of COVID-19.ResultsCirculating MT-DNA levels were highly elevated in patients who eventually died or required ICU admission, intubation, vasopressor use, or renal replacement therapy. Multivariate regression revealed that high circulating MT-DNA was an independent risk factor for these outcomes after adjusting for age, sex, and comorbidities. We also found that circulating MT-DNA levels had a similar or superior area under the curve when compared against clinically established measures of inflammation and emerging markers currently of interest as investigational targets for COVID-19 therapy.ConclusionThese results show that high circulating MT-DNA levels are a potential early indicator for poor COVID-19 outcomes.FundingWashington University Institute of Clinical Translational Sciences COVID-19 Research Program and Washington University Institute of Clinical Translational Sciences (ICTS) NIH grant UL1TR002345
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