Showing papers by "University of Western Ontario published in 2019"
TL;DR: In this article, the Event Horizon Telescope was used to reconstruct event-horizon-scale images of the supermassive black hole candidate in the center of the giant elliptical galaxy M87.
Abstract: When surrounded by a transparent emission region, black holes are expected to reveal a dark shadow caused by gravitational light bending and photon capture at the event horizon. To image and study this phenomenon, we have assembled the Event Horizon Telescope, a global very long baseline interferometry array observing at a wavelength of 1.3 mm. This allows us to reconstruct event-horizon-scale images of the supermassive black hole candidate in the center of the giant elliptical galaxy M87. We have resolved the central compact radio source as an asymmetric bright emission ring with a diameter of 42 +/- 3 mu as, which is circular and encompasses a central depression in brightness with a flux ratio greater than or similar to 10: 1. The emission ring is recovered using different calibration and imaging schemes, with its diameter and width remaining stable over four different observations carried out in different days. Overall, the observed image is consistent with expectations for the shadow of a Kerr black hole as predicted by general relativity. The asymmetry in brightness in the ring can be explained in terms of relativistic beaming of the emission from a plasma rotating close to the speed of light around a black hole. We compare our images to an extensive library of ray-traced general-relativistic magnetohydrodynamic simulations of black holes and derive a central mass of M = (6.5 +/- 0.7) x 10(9) M-circle dot. Our radio-wave observations thus provide powerful evidence for the presence of supermassive black holes in centers of galaxies and as the central engines of active galactic nuclei. They also present a new tool to explore gravity in its most extreme limit and on a mass scale that was so far not accessible.
2,589 citations
TL;DR: In this paper, the authors describe the fundamentals of the hydrogen evolution reaction/oxygen evolution reaction (HER/OER) and construct efficient electrocatalysts based on the structure-activity relationship.
Abstract: Alkaline water splitting is an attractive method for sustainable hydrogen production. Owing to the sluggish kinetics of alkaline water reduction and oxidation, it is crucial to understand the mechanism of the hydrogen evolution reaction/oxygen evolution reaction (HER/OER) and construct efficient electrocatalysts based on the structure–activity relationship. This review describes the fundamentals of the alkaline HER and OER, the design of noble and nonnoble HER electrocatalysts with low energy barriers, OER electrocatalysts based on binding energy, electronic structure, lattice oxygen, and surface reconstruction as well as the recent developments of bifunctional HER/OER electrocatalysts. Future perspectives towards alkaline water splitting electrocatalysts are also proposed.
874 citations
TL;DR: Gut-derived effects in humans is described, a review of current understanding of probiotics and prebiotics as a means to manage the microbiota to improve host health, including mechanisms of actions and potential for clinical use.
Abstract: Probiotics and prebiotics are microbiota-management tools for improving host health. They target gastrointestinal effects via the gut, although direct application to other sites such as the oral cavity, vaginal tract and skin is being explored. Here, we describe gut-derived effects in humans. In the past decade, research on the gut microbiome has rapidly accumulated and has been accompanied by increased interest in probiotics and prebiotics as a means to modulate the gut microbiota. Given the importance of these approaches for public health, it is timely to reiterate factual and supporting information on their clinical application and use. In this Review, we discuss scientific evidence on probiotics and prebiotics, including mechanistic insights into health effects. Strains of Lactobacillus, Bifidobacterium and Saccharomyces have a long history of safe and effective use as probiotics, but Roseburia spp., Akkermansia spp., Propionibacterium spp. and Faecalibacterium spp. show promise for the future. For prebiotics, glucans and fructans are well proven, and evidence is building on the prebiotic effects of other substances (for example, oligomers of mannose, glucose, xylose, pectin, starches, human milk and polyphenols).
813 citations
TL;DR: The known species repertoire of the collective human gut microbiota is substantially expanded with the discovery of 1,952 uncultured bacterial species that greatly improve classification of understudied African and South American samples.
Abstract: The composition of the human gut microbiota is linked to health and disease, but knowledge of individual microbial species is needed to decipher their biological roles. Despite extensive culturing and sequencing efforts, the complete bacterial repertoire of the human gut microbiota remains undefined. Here we identify 1,952 uncultured candidate bacterial species by reconstructing 92,143 metagenome-assembled genomes from 11,850 human gut microbiomes. These uncultured genomes substantially expand the known species repertoire of the collective human gut microbiota, with a 281% increase in phylogenetic diversity. Although the newly identified species are less prevalent in well-studied populations compared to reference isolate genomes, they improve classification of understudied African and South American samples by more than 200%. These candidate species encode hundreds of newly identified biosynthetic gene clusters and possess a distinctive functional capacity that might explain their elusive nature. Our work expands the known diversity of uncultured gut bacteria, which provides unprecedented resolution for taxonomic and functional characterization of the intestinal microbiota.
795 citations
TL;DR: The Event Horizon Telescope (EHT) as mentioned in this paper is a very long baseline interferometry (VLBI) array that comprises millimeter and submillimeter-wavelength telescopes separated by distances comparable to the diameter of the Earth.
Abstract: The Event Horizon Telescope (EHT) is a very long baseline interferometry (VLBI) array that comprises millimeter- and submillimeter-wavelength telescopes separated by distances comparable to the diameter of the Earth. At a nominal operating wavelength of ~1.3 mm, EHT angular resolution (λ/D) is ~25 μas, which is sufficient to resolve nearby supermassive black hole candidates on spatial and temporal scales that correspond to their event horizons. With this capability, the EHT scientific goals are to probe general relativistic effects in the strong-field regime and to study accretion and relativistic jet formation near the black hole boundary. In this Letter we describe the system design of the EHT, detail the technology and instrumentation that enable observations, and provide measures of its performance. Meeting the EHT science objectives has required several key developments that have facilitated the robust extension of the VLBI technique to EHT observing wavelengths and the production of instrumentation that can be deployed on a heterogeneous array of existing telescopes and facilities. To meet sensitivity requirements, high-bandwidth digital systems were developed that process data at rates of 64 gigabit s^(−1), exceeding those of currently operating cm-wavelength VLBI arrays by more than an order of magnitude. Associated improvements include the development of phasing systems at array facilities, new receiver installation at several sites, and the deployment of hydrogen maser frequency standards to ensure coherent data capture across the array. These efforts led to the coordination and execution of the first Global EHT observations in 2017 April, and to event-horizon-scale imaging of the supermassive black hole candidate in M87.
756 citations
Ghent University1, University of California, San Diego2, Leiden University3, Dresden University of Technology4, Stanford University5, University of Maryland, College Park6, Indiana University7, University of Cambridge8, Cardiff University9, University of Western Ontario10, Monash University, Clayton campus11, University of Toronto12, University of Vermont13, University of Oregon14, University of Tasmania15, University of Oslo16, Utrecht University17, Katholieke Universiteit Leuven18, Yale University19, Vanderbilt University20, University of Amsterdam21, Anglia Ruskin University22, Indian Institute of Science23, Queen's University24, King's College London25, Michigan State University26, University of Iowa27, Trinity College, Dublin28
TL;DR: The goal is to facilitate a more accurate use of the stop-signal task and provide user-friendly open-source resources intended to inform statistical-power considerations, facilitate the correct implementation of the task, and assist in proper data analysis.
Abstract: Response inhibition is essential for navigating everyday life. Its derailment is considered integral to numerous neurological and psychiatric disorders, and more generally, to a wide range of behavioral and health problems. Response-inhibition efficiency furthermore correlates with treatment outcome in some of these conditions. The stop-signal task is an essential tool to determine how quickly response inhibition is implemented. Despite its apparent simplicity, there are many features (ranging from task design to data analysis) that vary across studies in ways that can easily compromise the validity of the obtained results. Our goal is to facilitate a more accurate use of the stop-signal task. To this end, we provide 12 easy-to-implement consensus recommendations and point out the problems that can arise when they are not followed. Furthermore, we provide user-friendly open-source resources intended to inform statistical-power considerations, facilitate the correct implementation of the task, and assist in proper data analysis.
617 citations
TL;DR: This work reviews how photosynthesis, photorespiration and respiration are affected by increasing atmospheric CO2 concentrations and climate warming, both separately and in combination and highlights the need to study these physiological processes together to better predict how vegetation carbon metabolism will respond to climate change.
Abstract: Contents Summary 32 I. The importance of plant carbon metabolism for climate change 32 II. Rising atmospheric CO2 and carbon metabolism 33 III. Rising temperatures and carbon metabolism 37 IV. Thermal acclimation responses of carbon metabolic processes can be best understood when studied together 38 V. Will elevated CO2 offset warming-induced changes in carbon metabolism? 40 VI. No plant is an island: water and nutrient limitations define plant responses to climate drivers 41 VII. Conclusions 42 Acknowledgements 42 References 42 Appendix A1 48 SUMMARY: Plant carbon metabolism is impacted by rising CO2 concentrations and temperatures, but also feeds back onto the climate system to help determine the trajectory of future climate change. Here we review how photosynthesis, photorespiration and respiration are affected by increasing atmospheric CO2 concentrations and climate warming, both separately and in combination. We also compile data from the literature on plants grown at multiple temperatures, focusing on net CO2 assimilation rates and leaf dark respiration rates measured at the growth temperature (Agrowth and Rgrowth , respectively). Our analyses show that the ratio of Agrowth to Rgrowth is generally homeostatic across a wide range of species and growth temperatures, and that species that have reduced Agrowth at higher growth temperatures also tend to have reduced Rgrowth , while species that show stimulations in Agrowth under warming tend to have higher Rgrowth in the hotter environment. These results highlight the need to study these physiological processes together to better predict how vegetation carbon metabolism will respond to climate change.
476 citations
TL;DR: FNDC5/irisin is placed as a novel agent capable of opposing synapse failure and memory impairment in AD, and restoration of its expression can ameliorate these phenotypes in rodent models.
Abstract: Defective brain hormonal signaling has been associated with Alzheimer's disease (AD), a disorder characterized by synapse and memory failure. Irisin is an exercise-induced myokine released on cleavage of the membrane-bound precursor protein fibronectin type III domain-containing protein 5 (FNDC5), also expressed in the hippocampus. Here we show that FNDC5/irisin levels are reduced in AD hippocampi and cerebrospinal fluid, and in experimental AD models. Knockdown of brain FNDC5/irisin impairs long-term potentiation and novel object recognition memory in mice. Conversely, boosting brain levels of FNDC5/irisin rescues synaptic plasticity and memory in AD mouse models. Peripheral overexpression of FNDC5/irisin rescues memory impairment, whereas blockade of either peripheral or brain FNDC5/irisin attenuates the neuroprotective actions of physical exercise on synaptic plasticity and memory in AD mice. By showing that FNDC5/irisin is an important mediator of the beneficial effects of exercise in AD models, our findings place FNDC5/irisin as a novel agent capable of opposing synapse failure and memory impairment in AD.
433 citations
TL;DR: In this paper, a competitive complexation strategy has been developed to construct a novel electrocatalyst with Zn-Co atomic pairs coordinated on N doped carbon support (Zn/CoN-C).
Abstract: A competitive complexation strategy has been developed to construct a novel electrocatalyst with Zn-Co atomic pairs coordinated on N doped carbon support (Zn/CoN-C). Such architecture offers enhanced binding ability of O2 , significantly elongates the O-O length (from 1.23 A to 1.42 A), and thus facilitates the cleavage of O-O bond, showing a theoretical overpotential of 0.335 V during ORR process. As a result, the Zn/CoN-C catalyst exhibits outstanding ORR performance in both alkaline and acid conditions with a half-wave potential of 0.861 and 0.796 V respectively. The in situ XANES analysis suggests Co as the active center during the ORR. The assembled zinc-air battery with Zn/CoN-C as cathode catalyst presents a maximum power density of 230 mW cm-2 along with excellent operation durability. The excellent catalytic activity in acid is also verified by H2 /O2 fuel cell tests (peak power density of 705 mW cm-2 ).
414 citations
University of Southern California1, Huntington Medical Research Institutes2, University of Edinburgh3, University of Toronto4, Yale University5, Ludwig Maximilian University of Munich6, Cornell University7, University of Bristol8, Nottingham City Hospital9, University of Nottingham10, University of Cambridge11, University of Manchester12, University of Glasgow13, Newcastle University14, UCL Institute of Neurology15, University of Southampton16, British Heart Foundation17, King's College London18, Harvard University19, Mayo Clinic20, University of Illinois at Chicago21, University of Arizona22, University of British Columbia23, University of California, San Diego24, University of Washington25, Wake Forest University26, National University of Singapore27, University of New South Wales28, University of Gothenburg29, SUNY Downstate Medical Center30, Utrecht University31, University of Calgary32, The Chinese University of Hong Kong33, Queen's University Belfast34, University College London35, VU University Amsterdam36, VU University Medical Center37, University of Bonn38, German Center for Neurodegenerative Diseases39, Houston Methodist Hospital40, McGill University41, Boston University42, National Institutes of Health43, Johns Hopkins University44, Leiden University45, Rush University Medical Center46, University of Minnesota47, University of Western Ontario48
TL;DR: Vascular imaging biomarkers of small vessel disease of the brain, which is responsible for >50% of dementia worldwide, including AD, are already established, well characterized, and easy to recognize and should be incorporated into the AD Research Framework to gain a better understanding of AD pathophysiology and aid in treatment efforts.
Abstract: Increasing evidence recognizes Alzheimer's disease (AD) as a multifactorial and heterogeneous disease with multiple contributors to its pathophysiology, including vascular dysfunction. The recently updated AD Research Framework put forth by the National Institute on Aging-Alzheimer's Association describes a biomarker-based pathologic definition of AD focused on amyloid, tau, and neuronal injury. In response to this article, here we first discussed evidence that vascular dysfunction is an important early event in AD pathophysiology. Next, we examined various imaging sequences that could be easily implemented to evaluate different types of vascular dysfunction associated with, and/or contributing to, AD pathophysiology, including changes in blood-brain barrier integrity and cerebral blood flow. Vascular imaging biomarkers of small vessel disease of the brain, which is responsible for >50% of dementia worldwide, including AD, are already established, well characterized, and easy to recognize. We suggest that these vascular biomarkers should be incorporated into the AD Research Framework to gain a better understanding of AD pathophysiology and aid in treatment efforts.
407 citations
Laboratory of Molecular Biology1, University of Victoria2, University of Colorado Boulder3, National University of Singapore4, Pasteur Institute5, Biogen Idec6, Northeastern University7, University of Pennsylvania8, Novo Nordisk9, Scripps Research Institute10, Washington University in St. Louis11, University of Washington12, Johnson & Johnson13, Utrecht University14, University of Southern Denmark15, University of Massachusetts Amherst16, University of California, Berkeley17, University of Western Ontario18, Academy of Sciences of the Czech Republic19, Hebrew University of Jerusalem20, Iowa State University21, Hoffmann-La Roche22, Genentech23, University of Kansas24, York University25, University of Maryland, Baltimore26, Amgen27, University of Calgary28, University of Copenhagen29
TL;DR: Recommendations arising from community discussions emerging out of the first International Conference on Hydrogen-Exchange Mass Spectrometry (IC-HDX; 2017) are provided, meant to represent both a consensus viewpoint and an opportunity to stimulate further additions and refinements as the field advances.
Abstract: Hydrogen deuterium exchange mass spectrometry (HDX-MS) is a powerful biophysical technique being increasingly applied to a wide variety of problems. As the HDX-MS community continues to grow, adoption of best practices in data collection, analysis, presentation and interpretation will greatly enhance the accessibility of this technique to nonspecialists. Here we provide recommendations arising from community discussions emerging out of the first International Conference on Hydrogen-Exchange Mass Spectrometry (IC-HDX; 2017). It is meant to represent both a consensus viewpoint and an opportunity to stimulate further additions and refinements as the field advances.
TL;DR: In this article, a review describes recent progress in the design and synthesis of Pt-based catalysts with high atom utilization efficiency and their enhanced catalytic performance in electrochemical catalytic reactions.
Abstract: In recent years, development to increase the performance of Pt-based catalysts and reduce the cost has received significant attention. Among them, the preparation of Pt-based catalysts with high atom utilization efficiency can induce more active sites between the Pt atoms and participating molecules, resulting in improved mass activity. In addition, the combination of high atom utilization efficiency with well-controlled surface structure and composition could boost the mass activity for Pt-based catalysts. This review describes recent progress in the design and synthesis of Pt-based catalysts with high atom utilization efficiency and their enhanced catalytic performance in electrochemical catalytic reactions. The significance for the fabrication of nanostructures and single atom catalysts with high atom utilization will be presented in the introduction section. We discuss the synthetic strategies according to two routes: (1) the rational design of Pt nanostructures, including porous, nanowire, core–shell and hollow structures; and (2) preparation of Pt single atom catalysts and the stabilization of single atoms. Additionally, we discuss the superior electro-catalytic applications of Pt-based catalysts with high atom utilization efficiency. These recent advancements in rational design of Pt-based catalysts offer numerous cases for potential industrialized catalysts with high mass activity and reduced cost in the future.
TL;DR: The selection of highly promising bacterial and/or fungal consortium has the ability to produce various extracellular enzymes including cellulase, hemicellulase, and lignases which can be used in CBP for efficient biological pretreatment of lignocellulosic biomass following production of biofuels and bioproducts.
Abstract: Increasing energy demands are not only exploiting the fossil resources but, also depleting natural environment. Biofuels from lignocellulosic biomass is a renewable, ecofriendly, sustainable and could be a promising alternative to fossil fuels. However, pretreatment is an essential step to disarray the layers of lignocellulose prior to enzymatic hydrolysis. Among various pretreatments of lignocellulose, the biological pretreatment using microorganisms such as bacteria and fungi are gaining popularity due to its financial and environmental benefits. Careful selection of the suitable microbial consortium for efficient pretreatment of biomass is a critical step. The co-culture of bacteria and/or fungi in consolidated bioprocessing (CBP) is highly beneficial in the breakdown of complex biopolymers due to their high enzyme activity. Our selection of highly promising bacterial and/or fungal consortium has the ability to produce various extracellular enzymes including cellulase, hemicellulase, and lignases. It can be used in CBP for efficient biological pretreatment of lignocellulosic biomass following production of biofuels and bioproducts.
TL;DR: In this paper, a facile microwave reduction method was developed to synthesize single Pt atoms anchored on aniline-stacked graphene (Pt SASs/AG) with outstanding HER performance.
Abstract: Developing efficient and cost-effective electrocatalysts for hydrogen evolution reaction (HER) is highly desired for the hydrogen economy. In this study, we developed a facile microwave reduction method to synthesize single Pt atoms anchored on aniline-stacked graphene (Pt SASs/AG) with outstanding HER performance. Pt SASs/AG presents excellent HER activity with η = 12 mV at 10 mA cm−2 and a mass current density of 22 400 AgPt−1 at η = 50 mV, which is 46 times higher than that of commercial 20 wt% Pt/C. Moreover, the Pt SASs/AG catalyst is highly active and more stable than Pt/C. X-ray absorption fine spectroscopy and density functional theory calculations demonstrated that the coordination of atomically isolated Pt with the nitrogen of aniline optimized the electronic structure of Pt and the hydrogen adsorption energy, eventually promoting HER activity. This study provides a new avenue for the development of single-atom Pt electrocatalysts with high activity and stability.
TL;DR: Using a large task battery spanning motor, cognitive, social and affective domains, this functional MRI study provides a comprehensive functional map of the human cerebellum, along with a comparison to maps derived from anatomy and resting-state fMRI data.
Abstract: There is compelling evidence that the human cerebellum is engaged in a wide array of motor and cognitive tasks. A fundamental question centers on whether the cerebellum is organized into distinct functional subregions. To address this question, we employed a rich task battery designed to tap into a broad range of cognitive processes. During four functional MRI sessions, participants performed a battery of 26 diverse tasks comprising 47 unique conditions. Using the data from this multi-domain task battery, we derived a comprehensive functional parcellation of the cerebellar cortex and evaluated it by predicting functional boundaries in a novel set of tasks. The new parcellation successfully identified distinct functional subregions, providing significant improvements over existing parcellations derived from task-free data. Lobular boundaries, commonly used to summarize functional data, did not coincide with functional subdivisions. The new parcellation provides a functional atlas to guide future neuroimaging studies. Using a large task battery spanning motor, cognitive, social and affective domains, this functional MRI (fMRI) study provides a comprehensive functional map of the human cerebellum, along with a comparison to maps derived from anatomy and resting-state fMRI data.
TL;DR: Current understanding of circRNA biogenesis, properties, expression profiles, detection methods, functions, and their implication in cardiac pathologies including/ischemia reperfusion injury, myocardial infarction, cardiac senescence, cardiac fibrosis, cardiomyopathy, cardiac hypertrophy and heart failure are summarized.
Abstract: Circular RNA (circRNA) are endogenous transcripts that display differential expression across species, developmental stages, and pathologies. Their lack of free ends confers increased stability when compared with linear transcripts, making them ideal candidates for future diagnostic biomarkers and therapeutic interventions. Increasing evidence has implicated circRNA in the pathogenesis of multiple cardiovascular diseases. In this paper, we summarize current understanding of circRNA biogenesis, properties, expression profiles, detection methods, functions, and their implication in cardiac pathologies including/ischemia reperfusion injury, myocardial infarction, cardiac senescence, cardiac fibrosis, cardiomyopathy, cardiac hypertrophy and heart failure, atherosclerosis, coronary artery disease, and aneurysm.
TL;DR: This work summarises the arguments in favour of coproduction, the different approaches to establishing coproductive work and their costs, and proposes some preliminary advice to help decide whenCoproduction is likely to be more or less useful.
Abstract: Coproduction, a collaborative model of research that includes stakeholders in the research process, has been widely advocated as a means of facilitating research use and impact. We summarise the arguments in favour of coproduction, the different approaches to establishing coproductive work and their costs, and offer some advice as to when and how to consider coproduction. Despite the multiplicity of reasons and incentives to coproduce, there is little consensus about what coproduction is, why we do it, what effects we are trying to achieve, or the best coproduction techniques to achieve policy, practice or population health change. Furthermore, coproduction is not free risk or cost. Tensions can arise throughout coproduced research processes between the different interests involved. We identify five types of costs associated with coproduced research affecting the research itself, the research process, professional risks for researchers and stakeholders, personal risks for researchers and stakeholders, and risks to the wider cause of scholarship. Yet, these costs are rarely referred to in the literature, which generally calls for greater inclusion of stakeholders in research processes, focusing exclusively on potential positives. There are few tools to help researchers avoid or alleviate risks to themselves and their stakeholders. First, we recommend identifying specific motivations for coproduction and clarifying exactly which outcomes are required for whom for any particular piece of research. Second, we suggest selecting strategies specifically designed to enable these outcomes to be achieved, and properly evaluated. Finally, in the absence of strong evidence about the impact and process of coproduction, we advise a cautious approach to coproduction. This would involve conscious and reflective research practice, evaluation of how coproduced research practices change outcomes, and exploration of the costs and benefits of coproduction. We propose some preliminary advice to help decide when coproduction is likely to be more or less useful.
Stanford University1, California Institute of Technology2, University of California, Berkeley3, Ames Research Center4, Los Alamos National Laboratory5, Cornell University6, Lawrence Livermore National Laboratory7, University of Arizona8, National Research Council9, National Institutes of Natural Sciences, Japan10, Princeton University11, University of Notre Dame12, University of Georgia13, Université de Montréal14, University of Grenoble15, University of Chicago16, University of California, Los Angeles17, Amherst College18, University of California, Santa Cruz19, University of Victoria20, University of Michigan21, European Southern Observatory22, University of Exeter23, Arizona State University24, United States Geological Survey25, Pennsylvania State University26, Search for extraterrestrial intelligence27, University of California, San Diego28, University of Western Ontario29, Stony Brook University30, American Museum of Natural History31, Space Telescope Science Institute32, University of Cambridge33, Johns Hopkins University34, Leiden University35
TL;DR: Nielsen et al. as discussed by the authors presented a statistical analysis of the first 300 stars observed by the Gemini Planet Imager Exoplanet Survey (GPEES) to infer the underlying distributions of substellar companions with respect to their mass, semimajor axis, and host stellar mass.
Abstract: Author(s): Nielsen, EL; De Rosa, RJ; Macintosh, B; Wang, JJ; Ruffio, JB; Chiang, E; Marley, MS; Saumon, D; Savransky, D; Mark Ammons, S; Bailey, VP; Barman, T; Blain, C; Bulger, J; Burrows, A; Chilcote, J; Cotten, T; Czekala, I; Doyon, R; Duchene, G; Esposito, TM; Fabrycky, D; Fitzgerald, MP; Follette, KB; Fortney, JJ; Gerard, BL; Goodsell, SJ; Graham, JR; Greenbaum, AZ; Hibon, P; Hinkley, S; Hirsch, LA; Hom, J; Hung, LW; Ilene Dawson, R; Ingraham, P; Kalas, P; Konopacky, Q; Larkin, JE; Lee, EJ; Lin, JW; Maire, J; Marchis, F; Marois, C; Metchev, S; Millar-Blanchaer, MA; Morzinski, KM; Oppenheimer, R; Palmer, D; Patience, J; Perrin, M; Poyneer, L; Pueyo, L; Rafikov, RR; Rajan, A; Rameau, J; Rantakyro, FT; Ren, B; Schneider, AC; Sivaramakrishnan, A; Song, I; Soummer, R; Tallis, M; Thomas, S; Ward-Duong, K; Wolff, S | Abstract: We present a statistical analysis of the first 300 stars observed by the Gemini Planet Imager Exoplanet Survey. This subsample includes six detected planets and three brown dwarfs; from these detections and our contrast curves we infer the underlying distributions of substellar companions with respect to their mass, semimajor axis, and host stellar mass. We uncover a strong correlation between planet occurrence rate and host star mass, with stars M ∗ g1.5 M o more likely to host planets with masses between 2 and 13M Jup and semimajor axes of 3-100 au at 99.92% confidence. We fit a double power-law model in planet mass (m) and semimajor axis (a) for planet populations around high-mass stars (M ∗ g1.5 M o) of the form , finding α = -2.4 +0.8 and β = -2.0 +0.5, and an integrated occurrence rate of % between 5-13M Jup and 10-100 au. A significantly lower occurrence rate is obtained for brown dwarfs around all stars, with % of stars hosting a brown dwarf companion between 13-80M Jup and 10-100 au. Brown dwarfs also appear to be distributed differently in mass and semimajor axis compared to giant planets; whereas giant planets follow a bottom-heavy mass distribution and favor smaller semimajor axes, brown dwarfs exhibit just the opposite behaviors. Comparing to studies of short-period giant planets from the radial velocity method, our results are consistent with a peak in occurrence of giant planets between ∼1 and 10 au. We discuss how these trends, including the preference of giant planets for high-mass host stars, point to formation of giant planets by core/pebble accretion, and formation of brown dwarfs by gravitational instability.
TL;DR: A critical appraisal of the epidemiology, pathobiology, neuropathology, and neuroimaging of vascular cognitive impairment and dementia and of current diagnostic and therapeutic approaches is provided to shed light on new basic and clinical research avenues that may lead to mitigating one of the most devastating human conditions.
University of British Columbia1, Montreal Heart Institute2, Laval University3, Southlake Regional Health Center4, University of Western Ontario5, Royal Jubilee Hospital6, Centre Hospitalier Universitaire de Sherbrooke7, Queen Elizabeth II Health Sciences Centre8, St. Michael's Hospital9, University of Winnipeg10
TL;DR: In this multicenter, randomized, single-blinded trial, contact-force RF ablation and two different regiments of cryoballoon ablation resulted in no difference in one-year efficacy, which was 53% by time to first recurrence but >98% burden reduction as assessed by continuous cardiac rhythm monitoring.
Abstract: Background: Advanced generation ablation technologies have been developed to achieve more effective pulmonary vein isolation (PVI) and minimize arrhythmia recurrence after atrial fibrillation (AF) ...
TL;DR: Pt-Ru bimetallic dimer structures are prepared through atomic layer deposition process and the roles of Pt and Ru in hydrogen evolution reaction are identified.
Abstract: Single atom catalysts exhibit particularly high catalytic activities in contrast to regular nanomaterial-based catalysts. Until recently, research has been mostly focused on single atom catalysts, and it remains a great challenge to synthesize bimetallic dimer structures. Herein, we successfully prepare high-quality one-to-one A-B bimetallic dimer structures (Pt-Ru dimers) through an atomic layer deposition (ALD) process. The Pt-Ru dimers show much higher hydrogen evolution activity (more than 50 times) and excellent stability compared to commercial Pt/C catalysts. X-ray absorption spectroscopy indicates that the Pt-Ru dimers structure model contains one Pt-Ru bonding configuration. First principle calculations reveal that the Pt-Ru dimer generates a synergy effect by modulating the electronic structure, which results in the enhanced hydrogen evolution activity. This work paves the way for the rational design of bimetallic dimers with good activity and stability, which have a great potential to be applied in various catalytic reactions. Atomically precise control over elemental distributions presents a challenge in the preparation of catalytic nanomaterials. Here the authors report Pt-Ru bimetallic dimer structures through atomic layer deposition process and identify the roles of Pt and Ru in hydrogen evolution reaction.
TL;DR: The state‐of‐the‐art methods have been presented by conducting a detailed literature review of the recent applications of smartphones, UAVs, cameras, and robotic sensors used in acquiring and analyzing the vibration data for structural condition monitoring and maintenance.
TL;DR: Patients treated with radiotherapy showed superior swallowing-related QOL scores 1 year after treatment, although the difference did not represent a clinically meaningful change, and toxicity patterns differed between the groups.
Abstract: Summary Background Transoral robotic surgery (TORS) with concurrent neck dissection has supplanted radiotherapy in the USA as the most common treatment for oropharyngeal squamous cell carcinoma (OPSCC), yet no randomised trials have compared these modalities. We aimed to evaluate differences in quality of life (QOL) 1 year after treatment. Methods The ORATOR trial was an investigator-initiated, multicentre, international, open-label, parallel-group, phase 2, randomised study. Patients were enrolled at six hospitals in Canada and Australia. We randomly assigned (1:1) patients aged 18 years or older, with Eastern Cooperative Oncology Group scores of 0–2, and with T1–T2, N0–2 (≤4 cm) OPSCC tumour types to radiotherapy (70 Gy, with chemotherapy if N1–2) or TORS plus neck dissection (with or without adjuvant chemoradiotherapy, based on pathology). Following stratification by p16 status, patients were randomly assigned using a computer-generated randomisation list with permuted blocks of four. The primary endpoint was swallowing-related QOL at 1 year as established using the MD Anderson Dysphagia Inventory (MDADI) score, powered to detect a 10-point improvement (a clinically meaningful change) in the TORS plus neck dissection group. All analyses were done by intention to treat. This study is registered with ClinicalTrials.gov (NCT01590355) and is active, but not currently recruiting. Findings 68 patients were randomly assigned (34 per group) between Aug 10, 2012, and June 9, 2017. Median follow-up was 25 months (IQR 20–33) for the radiotherapy group and 29 months (23–43) for the TORS plus neck dissection group. MDADI total scores at 1 year were mean 86·9 (SD 11·4) in the radiotherapy group versus 80·1 (13·0) in the TORS plus neck dissection group (p=0·042). There were more cases of neutropenia (six [18%] of 34 patients vs none of 34), hearing loss (13 [38%] vs five [15%]), and tinnitus (12 [35%] vs two [6%]) reported in the radiotherapy group than in the TORS plus neck dissection group, and more cases of trismus in the TORS plus neck dissection group (nine [26%] vs one [3%]). The most common adverse events in the radiotherapy group were dysphagia (n=6), hearing loss (n=6), and mucositis (n=4), all grade 3, and in the TORS plus neck dissection group, dysphagia (n=9, all grade 3) and there was one death caused by bleeding after TORS. Interpretation Patients treated with radiotherapy showed superior swallowing-related QOL scores 1 year after treatment, although the difference did not represent a clinically meaningful change. Toxicity patterns differed between the groups. Patients with OPSCC should be informed about both treatment options. Funding Canadian Cancer Society Research Institute Grant (#701842), Ontario Institute for Cancer Research Clinician-Scientist research grant, and the Wolfe Surgical Research Professorship in the Biology of Head and Neck Cancers grant.
University of Liège1, French Institute of Health and Medical Research2, University of Buenos Aires3, Université Paris-Saclay4, Collège de France5, Pompeu Fabra University6, National Scientific and Technical Research Council7, University of Birmingham8, University of Western Ontario9, Columbia University10, Cornell University11
TL;DR: The results establish that consciousness rests on the brain’s ability to sustain rich brain dynamics and pave the way for determining specific and generalizable fingerprints of conscious and unconscious states.
Abstract: Adopting the framework of brain dynamics as a cornerstone of human consciousness, we determined whether dynamic signal coordination provides specific and generalizable patterns pertaining to conscious and unconscious states after brain damage. A dynamic pattern of coordinated and anticoordinated functional magnetic resonance imaging signals characterized healthy individuals and minimally conscious patients. The brains of unresponsive patients showed primarily a pattern of low interareal phase coherence mainly mediated by structural connectivity, and had smaller chances to transition between patterns. The complex pattern was further corroborated in patients with covert cognition, who could perform neuroimaging mental imagery tasks, validating this pattern’s implication in consciousness. Anesthesia increased the probability of the less complex pattern to equal levels, validating its implication in unconsciousness. Our results establish that consciousness rests on the brain’s ability to sustain rich brain dynamics and pave the way for determining specific and generalizable fingerprints of conscious and unconscious states.
TL;DR: In this paper, the authors comprehensively discuss the recent developments in advanced single-atom and dual-atom metal catalysts for the oxygen reduction reaction (ORR), including synthesis and characterization, reaction mechanisms and energy applications such as in fuel cells and metal-air batteries.
Abstract: In recent years, atomically dispersed metal catalysts (ADMCs) with well-defined structures have attracted great interest from researchers for electrocatalytic applications due to their maximum atom utilization efficiency (100%), distinct active sites and high catalytic activity, stability and selectivity. Based on this, this review will comprehensively discuss the recent developments in advanced single-atom and dual-atom ADMCs for the oxygen reduction reaction (ORR), including synthesis and characterization, reaction mechanisms and energy applications such as in fuel cells and metal–air batteries. In addition, challenges will be summarized and analyzed, including the rational design and fabrication of ADMCs and a deeper understanding of their geometric configuration, electronic structure and reaction dynamics towards the ORR. Furthermore, to facilitate further development, future research directions are proposed to overcome associated challenges, such as (1) the exploration of new/advanced materials including metal precursors and supporting substrates for the fabrication of ADMCs; (2) the optimization of rational design and synthesis techniques for single- and dual-atom catalysts to significantly enhance catalytic ORR activity and stability based on modern characterization techniques; (3) a deeper understanding of ADMC structures, reactive active sites, interactions between metal atoms and support surfaces and corresponding electrocatalytic ORR mechanisms at the atomic level using a combination of density functional theory (DFT) calculations and advanced experimental techniques; (4) the optimization of ADMC-based catalyst layers and membrane electrode assemblies to achieve high performance fuel cells and metal–air batteries using advanced electrochemical testing strategies.
TL;DR: In this scientific statement, an array of evidence-based considerations for testing of Lp(a) in clinical practice and the utilization of L p( a) levels to inform treatment strategies in primary and secondary prevention are reviewed.
McMaster University1, Juravinski Hospital2, University of Western Ontario3, Shaare Zedek Medical Center4, Hebrew University of Jerusalem5, French Institute of Health and Medical Research6, University of Poitiers7, University of Paris8, University Health Network9, University of Angers10, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico11, University of Milan12, Beth Israel Deaconess Medical Center13, University of Toronto14
TL;DR: In patients with acute hypoxemic respiratory failure, HFNC may decrease the need for tracheal intubation without impacting mortality, and Complications of treatment were variably reported amongst included studies, but little harm was associated with HFNC use.
Abstract: This systematic review and meta-analysis summarizes the safety and efficacy of high flow nasal cannula (HFNC) in patients with acute hypoxemic respiratory failure. We performed a comprehensive search of MEDLINE, EMBASE, and Web of Science. We identified randomized controlled trials that compared HFNC to conventional oxygen therapy. We pooled data and report summary estimates of effect using relative risk for dichotomous outcomes and mean difference or standardized mean difference for continuous outcomes, with 95% confidence intervals. We assessed risk of bias of included studies using the Cochrane tool and certainty in pooled effect estimates using GRADE methods. We included 9 RCTs (n = 2093 patients). We found no difference in mortality in patients treated with HFNC (relative risk [RR] 0.94, 95% confidence interval [CI] 0.67–1.31, moderate certainty) compared to conventional oxygen therapy. We found a decreased risk of requiring intubation (RR 0.85, 95% CI 0.74–0.99) or escalation of oxygen therapy (defined as crossover to HFNC in the control group, or initiation of non-invasive ventilation or invasive mechanical ventilation in either group) favouring HFNC-treated patients (RR 0.71, 95% CI 0.51–0.98), although certainty in both outcomes was low due to imprecision and issues related to risk of bias. HFNC had no effect on intensive care unit length of stay (mean difference [MD] 1.38 days more, 95% CI 0.90 days fewer to 3.66 days more, low certainty), hospital length of stay (MD 0.85 days fewer, 95% CI 2.07 days fewer to 0.37 days more, moderate certainty), patient reported comfort (SMD 0.12 lower, 95% CI 0.61 lower to 0.37 higher, very low certainty) or patient reported dyspnea (standardized mean difference [SMD] 0.16 lower, 95% CI 1.10 lower to 1.42 higher, low certainty). Complications of treatment were variably reported amongst included studies, but little harm was associated with HFNC use. In patients with acute hypoxemic respiratory failure, HFNC may decrease the need for tracheal intubation without impacting mortality.
TL;DR: The CoS3 catalyst plays a critical role in improving the sulfur utilization, especially in high-loading sulfur cathodes (3-10 mg cm-2 ), and the Li2 S/Li2 S2 ratio in the discharge products increased to 5.60/1 from 1/1.63, resulting in a sulfur utilization increase.
Abstract: Lithium-sulfur (Li-S) batteries with high sulfur loading are urgently required in order to take advantage of their high theoretical energy density. Ether-based Li-S batteries involve sophisticated multistep solid-liquid-solid-solid electrochemical reaction mechanisms. Recently, studies on Li-S batteries have widely focused on the initial solid (sulfur)-liquid (soluble polysulfide)-solid (Li2 S2 ) conversion reactions, which contribute to the first 50% of the theoretical capacity of the Li-S batteries. Nonetheless, the sluggish kinetics of the solid-solid conversion from solid-state intermediate product Li2 S2 to the final discharge product Li2 S (corresponding to the last 50% of the theoretical capacity) leads to the premature end of discharge, resulting in low discharge capacity output and low sulfur utilization. To tackle the aforementioned issue, a catalyst of amorphous cobalt sulfide (CoS3 ) is proposed to decrease the dissociation energy of Li2 S2 and propel the electrochemical transformation of Li2 S2 to Li2 S. The CoS3 catalyst plays a critical role in improving the sulfur utilization, especially in high-loading sulfur cathodes (3-10 mg cm-2 ). Accordingly, the Li2 S/Li2 S2 ratio in the discharge products increased to 5.60/1 from 1/1.63 with CoS3 catalyst, resulting in a sulfur utilization increase of 20% (335 mAh g-1 ) compared to the counterpart sulfur electrode without CoS3 .
01 Jan 2019
TL;DR: CBT is widely disseminated worldwide in professional training programs, conventions, and workshops, and hundreds of clinician and self-help CBT manuals and books have been published as discussed by the authors.
Abstract: 3 Cognitive-behavioral therapy (CBT) is the most well-established evidencebased psychotherapy and has been described as “the fastest growing and most heavily researched system of psychotherapy on the contemporary scene” (Prochaska & Norcross, 2010, p. 332). CBT is widely disseminated worldwide in professional training programs, conventions, and workshops, and hundreds of clinician and self-help CBT manuals and books have been published. Research supports the use of CBT in children, adolescents, adults, couples, and families for various psychiatric and medical disorders (cf. Beck & Dozois, 2011; Dobson & Dobson, 2017; Hofmann, 2013). CBT’s return on investment is substantial; an economic analysis estimated that the costs of treating anxiety and depression using evidence-based procedures, such as CBT, in 36 countries between 2016 and 2030 is $147 billion USD (Chisholm et al., 2016). However, scaling up treatment would lead to 43 million additional years of healthy life over this period, with a net economic gain of $310 billion. Mahoney (1977) noted that, whereas psychology had generally undergone a “cognitive revolution” in the 1960s, the same theoretical focus was brought to bear upon clinical psychology somewhat later. CBT first emerged in the early 1970s and only gradually gained traction among clinicians and researchers. It was not until the middle and later parts of the 1970s that the first major texts on “cognitive-behavior modification” appeared (Kendall & Hollon, 1979; Mahoney, 1974; Meichenbaum, 1977). The intervening period was one of considerable interest in cognition and in the application of cognitive C H A P T E R 1