8,482 research outputs found

    Piloting data linkage in a prospective cohort study of a GP referral scheme to avoid unnecessary emergency department conveyance

    Get PDF
    BACKGROUND: UK Ambulance services are under pressure to safely stream appropriate patients away from the Emergency Department (ED). Even so, there has been little evaluation of patient outcomes. We investigated differences between patients who are conveyed directly to ED after calling 999 and those referred by an ambulance crew to a novel GP referral scheme. METHODS: This was a prospective study comparing patients from two cohorts, one conveyed directly to the ED (n = 4219) and the other referred to a GP by the on-scene paramedic (n = 321). To compare differences in patient outcomes, we include follow-up data of a smaller subset of each cohort (up to n = 150 in each) including hospital admission, history of long-term illness, previous ED attendance, length of stay, hospital investigations, internal transfers, 30-day re-admission and 10-month mortality. RESULTS: Older individuals, females, and those with minor incidents were more likely to be referred to a GP than conveyed directly to ED. Of those patients referred to the GP, only 22.4% presented at ED within 30 days. These patients were more likely to be admitted then than were those initially conveyed directly to ED (59% vs 31%). Those conveyed to ED had a higher risk of death compared to those who were referred to the GP (HR: 2.59; 95% CI 1.14–5.89), however when analyses were restricted to those who presented at ED within 30 days, there was no difference in mortality risk (HR: 1.45; 95% CI 0.58–3.65). CONCLUSIONS: Despite limited data and a small sample size, there were differences between patients conveyed directly to ED and those who were referred into GP care. Initial evidence suggests that referring individuals to a GP may provide an appropriate and safe alternative path of care. This pilot study demonstrated a need for larger scale, methodologically rigorous study to demonstrate the benefits of alternative conveyance schemes and recommend changes to the current system of urgent and emergency care

    Shifting echo chambers in US climate policy networks

    Get PDF
    This is the final version. Available on open access from Public Library of Science via the DOI in this recordData Availability: Data are available from the Climate Constituencies study at http://drfisher.umd.edu/CCP_REVISED.html.Although substantial attention has focused on efforts by the new Administration to block environmental policies, climate politics have been contentious in the US since well before the election of Donald Trump. In this paper, we extend previous work on empirical examinations of echo chambers in US climate politics using new data collected on the federal climate policy network in summer 2016. We test for the similarity and differences at two points in time in homophily and echo chambers using Exponential Random Graph Models (ERGM) to compare new findings from 2016 to previous work on data from 2010. We show that echo chambers continue to play a significant role in the network of information exchange among policy elites working on the issue of climate change. In contrast to previous findings where echo chambers centered on a binding international commitment to emission reductions, we find that the pre-existing echo chambers have almost completely disappeared and new structures have formed around one of the main components of the Obama Administration’s national climate policy: the Clean Power Plan. These results provide empirical evidence that science communication and policymaking at the elite level shift in relation to the policy instruments under consideration.MacArthur Foundatio

    A Systematic Review of Magnesium Sulfate for Perinatal Neuroprotection: What Have We Learnt From the Past Decade?

    Get PDF
    There is an important unmet need to improve long term outcomes of encephalopathy for preterm and term infants. Meta-analyses of large controlled trials suggest that maternal treatment with magnesium sulfate (MgSO4) is associated with a reduced risk of cerebral palsy and gross motor dysfunction after premature birth. However, to date, follow up to school age has found an apparent lack of long-term clinical benefit. Because of this inconsistency, it remains controversial whether MgSO4 offers sustained neuroprotection. We systematically reviewed preclinical and clinical studies reported from January 1 2010, to January 31 2020 to evaluate the most recent advances and knowledge gaps relating to the efficacy of MgSO4 for the treatment of perinatal brain injury. The outcomes of MgSO4 in preterm and term-equivalent animal models of perinatal encephalopathy were highly inconsistent between studies. None of the perinatal rodent studies that suggested benefit directly controlled body or brain temperature. The majority of the studies did not control for sex, study long term histological and functional outcomes or use pragmatic treatment regimens and many did not report controlling for potential study bias. Finally, most of the recent preterm or term human studies that tested the potential of MgSO4 for perinatal neuroprotection were relatively underpowered, but nevertheless, suggest that any improvements in neurodevelopment were at best modest or absent. On balance, these data suggest that further rigorous testing in translational preclinical models of perinatal encephalopathy is essential to ensure safety and best regimens for optimal preterm neuroprotection, and before further clinical trials of MgSO4 for perinatal encephalopathy at term are undertaken

    Recruitment of insulin receptor substrate-1 by erbB3 impacts on IGF-IR signalling in oestrogen receptor-positive breast cancer cells

    Get PDF
    Insulin-like growth factor receptor (IGF-IR) signalling classically involves phosphorylation of insulin receptor substrate-1 (IRS-1) to recruit key down-stream signalling pathways effecting breast cancer cell proliferation and survival. Recently, we have shown a further capacity for IRS-1 to associate with the epidermal growth factor receptor (EGFR/erbB1), with activation of EGFR promoting recruitment and phosphorylation of IRS-1 in an oestrogen receptor (ER)-positive tamoxifen-resistant breast cancer cell line. In this study, we examined recruitment of IRS-1 by another member of the erbB receptor family, erbB3, in three ER-positive breast cancer cell lines. Our studies revealed an interaction between erbB3 and IRS-1 in MCF-7, T47D and BT474 cells with HRGβ1 treatment significantly enhancing this recruitment and promoting IRS-1 phosphorylation at tyrosine (Y) 612, a specific phosphoinositide 3-kinase (PI3K) binding site. IRS-1 appears to play a key role in erbB3 signalling in MCF-7 and T47D cells as its knockdown using siRNA greatly impaired HRGβ1 signalling via PI3K/AKT in these cell lines. This novel interaction may have clinical relevance as immunohistochemical analysis of ER-positive breast cancer patient samples revealed IRS-1 Y612 expression positively correlated with total erbB3, p-AKT and Ki67 expression. Importantly, we found that recruitment of IRS-1 by erbB3 impaired IRS-1 recruitment by IGF-IR in both MCF-7 and T47D cells, whilst blockade of IGF-1R enhanced erbB3/IRS-1 interaction and sensitised both cell lines to HRGβ1. Consequently, blockade of erbB3 signalling enhanced the effects of IGF-IR inhibition in these cells. In conclusion, these and previous findings suggest that IRS-1 can be recruited to IGF-1R, EGFR and erbB3 in ER-positive breast cancer cells and this may provide an adaptive resistance mechanism when these receptors are targeted individually. Consequently co-targeting of IGF-IR and erbB receptors may prove to be a more effective strategy for the treatment of ER-positive breast cancer

    Crystal sedimentation and stone formation

    Get PDF
    Mechanisms of crystal collision being the first step of aggregation (AGN) were analyzed for calcium oxalate monohydrate (COM) directly produced in urine. COM was produced by oxalate titration in urine of seven healthy men, in solutions of urinary macromolecules and in buffered distilled water (control). Crystal formation and sedimentation were followed by a spectrophotometer and analyzed by scanning electron microscopy. Viscosity of urine was measured at 37°C. From results, sedimentation rate (vS), particle diffusion (D) and incidences of collision of particles in suspension by sedimentation (IS) and by diffusion (ID) were calculated. Calculations were related to average volume and urinary transit time of renal collecting ducts (CD) and of renal pelvis. vS was in urine 0.026 ± 0.012, in UMS 0.022 ± 0.01 and in control 0.091 ± 0.02 cm min−1 (mean ± SD). For urine, a D of 9.53 ± 0.97 μm within 1 min can be calculated. At maximal crystal concentration, IS was only 0.12 and ID was 0.48 min−1 cm−3 which, even at an unrealistic permanent and maximal crystalluria, would only correspond to less than one crystal collision/week/CD, whereas to the same tubular wall being in horizontal position 1.3 crystals/min and to a renal stone 624 crystals/cm2 min could drop by sedimentation. Sedimentation to renal tubular or pelvic wall, where crystals can accumulate and meet with a tissue calcification or a stone, is probably essential for stone formation. Since vS mainly depends on particle size, reducing urinary supersaturation and crystal growth by dietary oxalate restriction seems to be an important measure to prevent aggregation

    The Caenorhabditis chemoreceptor gene families

    Get PDF
    Background: Chemoreceptor proteins mediate the first step in the transduction of environmental chemical stimuli, defining the breadth of detection and conferring stimulus specificity. Animal genomes contain families of genes encoding chemoreceptors that mediate taste, olfaction, and pheromone responses. The size and diversity of these families reflect the biology of chemoperception in specific species. Results: Based on manual curation and sequence comparisons among putative G-protein-coupled chemoreceptor genes in the nematode Caenorhabditis elegans, we identified approximately 1300 genes and 400 pseudogenes in the 19 largest gene families, most of which fall into larger superfamilies. In the related species C. briggsae and C. remanei, we identified most or all genes in each of the 19 families. For most families, C. elegans has the largest number of genes and C. briggsae the smallest number, suggesting changes in the importance of chemoperception among the species. Protein trees reveal family-specific and species-specific patterns of gene duplication and gene loss. The frequency of strict orthologs varies among the families, from just over 50% in two families to less than 5% in three families. Several families include large species-specific expansions, mostly in C. elegans and C. remanei. Conclusion: Chemoreceptor gene families in Caenorhabditis species are large and evolutionarily dynamic as a result of gene duplication and gene loss. These dynamics shape the chemoreceptor gene complements in Caenorhabditis species and define the receptor space available for chemosensory responses. To explain these patterns, we propose the gray pawn hypothesis: individual genes are of little significance, but the aggregate of a large number of diverse genes is required to cover a large phenotype space.JHT was supported by NIH grant RO1GM48700 and HMR by R01AI56081

    Longer fixation duration while viewing face images

    Get PDF
    The spatio-temporal properties of saccadic eye movements can be influenced by the cognitive demand and the characteristics of the observed scene. Probably due to its crucial role in social communication, it is argued that face perception may involve different cognitive processes compared with non-face object or scene perception. In this study, we investigated whether and how face and natural scene images can influence the patterns of visuomotor activity. We recorded monkeys’ saccadic eye movements as they freely viewed monkey face and natural scene images. The face and natural scene images attracted similar number of fixations, but viewing of faces was accompanied by longer fixations compared with natural scenes. These longer fixations were dependent on the context of facial features. The duration of fixations directed at facial contours decreased when the face images were scrambled, and increased at the later stage of normal face viewing. The results suggest that face and natural scene images can generate different patterns of visuomotor activity. The extra fixation duration on faces may be correlated with the detailed analysis of facial features

    Ring distributions leading to species formation: a global topographic analysis of geographic barriers associated with ring species

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>In the mid 20<sup>th </sup>century, Ernst Mayr and Theodosius Dobzhansky championed the significance of circular overlaps or ring species as the perfect demonstration of speciation, yet in the over 50 years since, only a handful of such taxa are known. We developed a topographic model to evaluate whether the geographic barriers that favor processes leading to ring species are common or rare, and to predict where other candidate ring barriers might be found.</p> <p>Results</p> <p>Of the 952,147 geographic barriers identified on the planet, only about 1% are topographically similar to barriers associated with known ring taxa, with most of the likely candidates occurring in under-studied parts of the world (for example, marine environments, tropical latitudes). Predicted barriers separate into two distinct categories: (i) single cohesive barriers (< 50,000 km<sup>2</sup>), associated with taxa that differentiate at smaller spatial scales (salamander: <it>Ensatina eschscholtzii</it>; tree: <it>Acacia karroo</it>); and (ii) composite barriers - formed by groups of barriers (each 184,000 to 1.7 million km<sup>2</sup>) in close geographic proximity (totaling 1.9 to 2.3 million km<sup>2</sup>) - associated with taxa that differentiate at larger spatial scales (birds: <it>Phylloscopus trochiloide</it>s and <it>Larus </it>(sp. <it>argentatus </it>and <it>fuscus</it>)). When evaluated globally, we find a large number of cohesive barriers that are topographically similar to those associated with known ring taxa. Yet, compared to cohesive barriers, an order of magnitude fewer composite barriers are similar to those that favor ring divergence in species with higher dispersal.</p> <p>Conclusions</p> <p>While these findings confirm that the topographic conditions that favor evolutionary processes leading to ring speciation are, in fact, rare, they also suggest that many understudied natural systems could provide valuable demonstrations of continuous divergence towards the formation of new species. Distinct advantages of the model are that it (i) requires no <it>a priori </it>information on the relative importance of features that define barriers, (ii) can be replicated using any kind of continuously distributed environmental variable, and (iii) generates spatially explicit hypotheses of geographic species formation. The methods developed here - combined with study of the geographical ecology and genetics of taxa in their environments - should enable recognition of ring species phenomena throughout the world.</p
    corecore