561 research outputs found

    From the margins to the mainstream: deconstructing science communication as a white, Western paradigm

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    In this commentary we are concerned with what mainstream science communication has neglected through cultural narrowness and ambient racism: other practitioners, missing audiences, unvalued knowledge, unrecognised practices. We explore examples from First Nations Peoples in the lands now known as Australia, from Griots in West Africa and from People's Science Movements in India to help us reimagine science communication. To develop meaningfully inclusive approaches to science communication, we argue there is an urgent need for the ‘mainstream’ to recognise, value and learn from science communication practices that are all too often seen as at ‘the margins’ of this field

    Deep learning to detect optical coherence tomography-derived diabetic macular edema from retinal photographs: a multicenter validation study

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    PURPOSE: To validate the generalizability of a deep learning system (DLS) that detects diabetic macular edema (DME) from two-dimensional color fundus photography (CFP), where the reference standard for retinal thickness and fluid presence is derived from three-dimensional optical coherence tomography (OCT). DESIGN: Retrospective validation of a DLS across international datasets. PARTICIPANTS: Paired CFP and OCT of patients from diabetic retinopathy (DR) screening programs or retina clinics. The DLS was developed using datasets from Thailand, the United Kingdom (UK) and the United States and validated using 3,060 unique eyes from 1,582 patients across screening populations in Australia, India and Thailand. The DLS was separately validated in 698 eyes from 537 screened patients in the UK with mild DR and suspicion of DME based on CFP. METHODS: The DLS was trained using DME labels from OCT. Presence of DME was based on retinal thickening or intraretinal fluid. The DLS's performance was compared to expert grades of maculopathy and to a previous proof-of-concept version of the DLS. We further simulated integration of the current DLS into an algorithm trained to detect DR from CFPs. MAIN OUTCOME MEASURES: Superiority of specificity and non-inferiority of sensitivity of the DLS for the detection of center-involving DME, using device specific thresholds, compared to experts. RESULTS: Primary analysis in a combined dataset spanning Australia, India, and Thailand showed the DLS had 80% specificity and 81% sensitivity compared to expert graders who had 59% specificity and 70% sensitivity. Relative to human experts, the DLS had significantly higher specificity (p=0.008) and non-inferior sensitivity (p 50%) and a sensitivity of 100% (p=0.02 for sensitivity > 90%). CONCLUSIONS: The DLS can generalize to multiple international populations with an accuracy exceeding experts. The clinical value of this DLS to reduce false positive referrals, thus decreasing the burden on specialist eye care, warrants prospective evaluation

    Endoscopic sinus surgery for maxillary sinus mucoceles

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    BACKGROUND: Maxillary sinus mucoceles are relatively rare among all paranasal sinus mucoceles. With the introduction of endoscopic sinus surgical techniques, rhinologic surgeons prefer transnasal endoscopic management of sinus mucoceles. The aim of this study is to describe the clinical presentation of maxillary sinus mucoceles and to establish the efficacy of endoscopic management of sinus mucoceles. METHODS: Between 2003 and 2005, 14 patients underwent endoscopic sinus surgery for maxillary sinus mucocele. The presenting sign and symptoms, radiological findings, surgical management and need for revision surgery were reviewed. RESULTS: There were eight males and six females with an age range of 14 to 65. Ten patients complained of nasal obstruction, five of nasal drainage, five of cheek pressure or pain and one of proptosis of the eye and cheek swelling. The maxillary sinus and ipsilateral ethmoid sinus involvement on computed tomographic studies was seen in 4 patients. Four patients had history of endoscopic ethmoidectomy surgery for ethmoid sinusitis and one had Caldwell-Luc operation in the past. Ethmoidectomy with middle meatal antrostomy and marsupialization of the mucocele was performed in all patients. Postoperative follow-up ranged between 8 to 48 months. All patients had a patent middle meatal antrostomy and healthy maxillary sinus mucosa. No patients need revision surgery. CONCLUSION: The most common causes of mucoceles are chronic infection, allergic sinonasal disease, trauma and previous surgery. In 64% of the patients of our study cause remains uncertain. Endoscopic sinus surgery is an effective treatment for maxillary sinus mucoceles with a favorable long-term outcome

    Medico-legal autopsy in postoperative hemodynamic collapse following coronary artery bypass surgery

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    Sudden unexpected postoperative hemodynamic collapse with a high mortality develops in 1–3% of patients undergoing coronary artery bypass surgery (CABG). The contribution of surgical graft complications to this serious condition is poorly known and their demonstration at autopsy is a challenging task. Isolated CABG was performed in 8,807 patients during 1988–1999. Of the patients, 76 (0.9%) developed sudden postoperative hemodynamic collapse resulting in subsequent emergency reopening of the median sternotomy and open cardiac massage. Further emergency reoperation could be performed in 62 (82%) whereas 14 patients died prior to reoperation and a further 21 did not survive the reoperation or died a few days later. All 35 (46%) patients who did not survive were subjected to medico-legal autopsy combined with postmortem cast angiography. By combining clinical data with autopsy and angiography data, various types of graft complications were observed in 27 (36%, 1.3 per patient) of the 76 patients with hemodynamic collapse. There were no significant differences in the frequency (33 vs. 40%) or number of complicated grafts per patient (1.2 vs. 1.4) between those who survived reoperation and who did not. Autopsy detected 25 major and minor findings not diagnosed clinically. Postmortem cast angiography visualized 2 graft twists not possible to detect by autopsy dissection only. Surgical graft complications were the most frequent single cause for sudden postoperative hemodynamic collapse in CABG patients leading to a fatal outcome in almost half of the cases. Postmortem angiography improved the accuracy of autopsy diagnostics of graft complications

    Intraoperative monitoring study of ipsilateral motor evoked potentials in scoliosis surgery

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    Ipsilateral motor evoked potentials (MEPs) in spinal cord surgery intraoperative monitoring is not well studied. We show that ipsilateral MEPs have significantly larger amplitudes and were elicited with lower stimulation intensities than contralateral MEPs. The possible underlying mechanisms are discussed based on current knowledge of corticospinal pathways. Ipsilateral MEPs may provide additional information on the integrity of descending motor tracts during spinal surgery monitoring

    Metabolome Based Reaction Graphs of M. tuberculosis and M. leprae: A Comparative Network Analysis

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    BACKGROUND: Several types of networks, such as transcriptional, metabolic or protein-protein interaction networks of various organisms have been constructed, that have provided a variety of insights into metabolism and regulation. Here, we seek to exploit the reaction-based networks of three organisms for comparative genomics. We use concepts from spectral graph theory to systematically determine how differences in basic metabolism of organisms are reflected at the systems level and in the overall topological structures of their metabolic networks. METHODOLOGY/PRINCIPAL FINDINGS: Metabolome-based reaction networks of Mycobacterium tuberculosis, Mycobacterium leprae and Escherichia coli have been constructed based on the KEGG LIGAND database, followed by graph spectral analysis of the network to identify hubs as well as the sub-clustering of reactions. The shortest and alternate paths in the reaction networks have also been examined. Sub-cluster profiling demonstrates that reactions of the mycolic acid pathway in mycobacteria form a tightly connected sub-cluster. Identification of hubs reveals reactions involving glutamate to be central to mycobacterial metabolism, and pyruvate to be at the centre of the E. coli metabolome. The analysis of shortest paths between reactions has revealed several paths that are shorter than well established pathways. CONCLUSIONS: We conclude that severe downsizing of the leprae genome has not significantly altered the global structure of its reaction network but has reduced the total number of alternate paths between its reactions while keeping the shortest paths between them intact. The hubs in the mycobacterial networks that are absent in the human metabolome can be explored as potential drug targets. This work demonstrates the usefulness of constructing metabolome based networks of organisms and the feasibility of their analyses through graph spectral methods. The insights obtained from such studies provide a broad overview of the similarities and differences between organisms, taking comparative genomics studies to a higher dimension

    Feature Selection via Chaotic Antlion Optimization

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    Selecting a subset of relevant properties from a large set of features that describe a dataset is a challenging machine learning task. In biology, for instance, the advances in the available technologies enable the generation of a very large number of biomarkers that describe the data. Choosing the more informative markers along with performing a high-accuracy classification over the data can be a daunting task, particularly if the data are high dimensional. An often adopted approach is to formulate the feature selection problem as a biobjective optimization problem, with the aim of maximizing the performance of the data analysis model (the quality of the data training fitting) while minimizing the number of features used.This work was partially supported by the IPROCOM Marie Curie initial training network, funded through the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme FP7/2007-2013/ under REA grants agreement No. 316555, and by the Romanian National Authority for Scientific Research, CNDIUEFISCDI, project number PN-II-PT-PCCA-2011-3.2- 0917. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Optical Trapping with High Forces Reveals Unexpected Behaviors of Prion Fibrils

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    Amyloid fibrils are important in diverse cellular functions, feature in many human diseases and have potential applications in nanotechnology. Here we describe methods that combine optical trapping and fluorescent imaging to characterize the forces that govern the integrity of amyloid fibrils formed by a yeast prion protein. A crucial advance was to use the self-templating properties of amyloidogenic proteins to tether prion fibrils, enabling their manipulation in the optical trap. At normal pulling forces the fibrils were impervious to disruption. At much higher forces (up to 250 pN), discontinuities occurred in force-extension traces before fibril rupture. Experiments with selective amyloid-disrupting agents and mutations demonstrated that such discontinuities were caused by the unfolding of individual subdomains. Thus, our results reveal unusually strong noncovalent intermolecular contacts that maintain fibril integrity even when individual monomers partially unfold and extend fibril length.National Institutes of Health (U.S.) (Grant GM025874)National Science Foundation (U.S.). CAREER (Award 0643745
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