1. |
- Gohir, Sameer Akram, et al.
(author)
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Effectiveness of Internet-Based Exercises Aimed at Treating Knee Osteoarthritis : The iBEAT-OA Randomized Clinical Trial
- 2021
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In: JAMA Network Open. - : American Medical Association (AMA). - 2574-3805. ; 4:2, s. 210012-210012
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Journal article (peer-reviewed)abstract
- Importance: Osteoarthritis is a prevalent, debilitating, and costly chronic disease for which recommended first-line treatment is underused.Objective: To compare the effect of an internet-based treatment for knee osteoarthritis vs routine self-management (ie, usual care).Design, Setting, and Participants: This randomized clinical trial was conducted from October 2018 to March 2020. Participants included individuals aged 45 years or older with a diagnosis of knee osteoarthritis recruited from an existing primary care database or from social media advertisements were invited. Data were analyzed April to July 2020.Interventions: The intervention and control group conformed to first-line knee osteoarthritis treatment. For the intervention group, treatment was delivered via a smartphone application. The control group received routine self-management care.Main Outcomes and Measures: The primary outcome was change from baseline to 6 weeks in self-reported pain during the last 7 days, reported on a numerical rating scale (NRS; range, 0-10, with 0 indicating no pain and 10, worst pain imaginable), compared between groups. Secondary outcomes included 2 physical functioning scores, hamstring and quadriceps muscle strength, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and quantitative sensory testing.Results: Among a total of 551 participants screened for eligibility, 146 were randomized and 105 were analyzed (mean [SD] age, 66.7 [9.2] years, 71 [67.1%] women), including 48 participants in the intervention group and 57 participants in the control group. There were no significant differences in baseline characteristics between the groups. At the 6-week follow-up, the intervention group showed a greater NRS pain score reduction than the control group (between-group difference, -1.5 [95% CI, -2.2 to -0.8]; P < .001). Similarly, the intervention group had better improvements in the 30-second sit-to-stand test (between-group difference, 3.4 [95% CI, 2.2 to 4.5]; P < .001) and Timed Up-and-Go test (between-group difference, -1.8 [95% CI, -3.0 to -0.5] seconds; P = .007), as well as the WOMAC subscales for pain (between-group difference, -1.1 [95% CI, -2.0 to -0.2]; P = .02), stiffness (between-group difference, -1.0 [95% CI, -1.5 to -0.5]; P < .001), and physical function (between-group difference, -3.4 [95% CI, -6.2 to -0.7]; P = .02). The magnitude of within-group changes in pain (d = 0.83) and function outcomes (30 second sit-to-stand test d = 1.24; Timed Up-and-Go test d = 0.76) in the intervention group corresponded to medium to very strong effects. No adverse events were reported.Conclusions and Relevance: These findings suggest that this internet-delivered, evidence-based, first-line osteoarthritis treatment was superior to routine self-managed usual care and could be provided without harm to people with osteoarthritis. Effect sizes observed in the intervention group corresponded to clinically important improvements.Trial Registration: ClinicalTrials.gov Identifier: NCT03545048.
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2. |
- Haugen, Ida K., et al.
(author)
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Development of radiographic classification criteria for hand osteoarthritis : a methodological report (Phase 2)
- 2022
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In: RMD Open. - : BMJ. - 2056-5933. ; 8:1
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Journal article (peer-reviewed)abstract
- ObjectivesIn Phase 1 of developing new hand osteoarthritis (OA) classification criteria, features associated with hand OA were identified in a population with hand complaints. Radiographic findings could better discriminate patients with hand OA and controls than clinical examination findings. The objective of Phase 2 was to achieve consensus on the features and their weights to be included in three radiographic criteria sets of overall hand OA, interphalangeal OA and thumb base OA.MethodsMultidisciplinary, international expert panels were convened. Patient vignettes were used to identify important features consistent with hand OA. A consensus-based decision analysis approach implemented using 1000minds software was applied to identify the most important features and their relative importance influencing the likelihood of symptoms being due to hand OA. Analyses were repeated for interphalangeal and thumb base OA. The reliability and validity of the proposed criteria sets were tested.ResultsThe experts agreed that the criteria sets should be applied in a population with pain, aching or stiffness in hand joint(s) not explained by another disease or acute injury. In this setting, five additional criteria were considered important: age, morning stiffness, radiographic osteophytes, radiographic joint space narrowing and concordance between symptoms and radiographic findings. The reliability and validity were very good.ConclusionRadiographic features were considered critical when determining whether a patient had symptoms due to hand OA. The consensus-based decision analysis approach in Phase 2 complemented the data-driven results from Phase 1, which will form the basis of the final classification criteria sets.
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3. |
- Kundakci, Burak, et al.
(author)
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International, multidisciplinary Delphi consensus recommendations on non-pharmacological interventions for fibromyalgia
- 2022
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In: Seminars in Arthritis & Rheumatism. - : Elsevier BV. - 0049-0172 .- 1532-866X. ; 57
-
Journal article (peer-reviewed)abstract
- Objectives: To develop evidence-based expert recommendations for non-pharmacological treatments for pain, fatigue, sleep problems, and depression in fibromyalgia.Methods: An international, multidisciplinary Delphi exercise was conducted. Authors of EULAR and the Canadian Fibromyalgia Guidelines Group, members of the American Pain Society and clinicians with expertise in fibromyalgia were invited. Participants were asked to select non-pharmacological interventions that could be offered for specific fibromyalgia symptoms and to classify them as either core or adjunctive treatments. An evidence summary was provided to aid the decision making. Items receiving >70% votes were accepted, those receiving <30% votes were rejected and those obtaining 30-70% votes were recirculated for up to two additional rounds.Results: Seventeen experts participated (Europe (n = 10), North America (n = 6), and Israel (n = 1)) in the Delphi exercise and completed all three rounds. Aerobic exercise, education, sleep hygiene and cognitive behavioural therapy were recommended as core treatments for all symptoms. Mind-body exercises were recommended as core interventions for pain, fatigue and sleep problems. Mindfulness was voted core treatment for depression, and adjunctive treatment for other symptoms. Other interventions, namely music, relaxation, hot bath, and local heat were voted as adjunctive treatments, varying between symptoms.Conclusions: This study provided evidence-based expert consensus recommendations on non-pharmacological treatments for fibromyalgia that may be used to individualise treatments in clinical practice targeting the diverse symptoms associated with fibromyalgia.
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4. |
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5. |
- Abbasi, Rasha, et al.
(author)
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IceCube search for neutrinos from GRB 221009A
- 2023
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In: Proceedings of 38th International Cosmic Ray Conference (ICRC 2023). - : Sissa Medialab Srl.
-
Conference paper (peer-reviewed)abstract
- GRB 221009A is the brightest Gamma Ray Burst (GRB) ever observed. The observed extremelyhigh flux of high and very-high-energy photons provide a unique opportunity to probe the predictedneutrino counterpart to the electromagnetic emission. We have used a variety of methods to searchfor neutrinos in coincidence with the GRB over several time windows during the precursor, promptand afterglow phases of the GRB. MeV scale neutrinos are studied using photo-multiplier ratescalers which are normally used to search for galactic core-collapse supernovae neutrinos. GeVneutrinos are searched starting with DeepCore triggers. These events don’t have directionallocalization, but instead can indicate an excess in the rate of events. 10 GeV - 1 TeV and >TeVneutrinos are searched using traditional neutrino point source methods which take into accountthe direction and time of events with DeepCore and the entire IceCube detector respectively. The>TeV results include both a fast-response analysis conducted by IceCube in real-time with timewindows of T0 − 1 to T0 + 2 hours and T0 ± 1 day around the time of GRB 221009A, as well asan offline analysis with 3 new time windows up to a time window of T0 − 1 to T0 + 14 days, thelongest time period we consider. The combination of observations by IceCube covers 9 ordersof magnitude in neutrino energy, from MeV to PeV, placing upper limits across the range forpredicted neutrino emission.
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6. |
- Abhishek, Sarabjot, et al.
(author)
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Estimation of Uranium and Related Health Risks Due to Consumption of Groundwater in Lower Himalayas
- 2023
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In: Indian Journal of Pure & Applied Physics. - : CSIR-National Institute of Science Communication and Policy Research (NIScPR). - 0019-5596 .- 0975-1041. ; 61:6, s. 478-483
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Journal article (peer-reviewed)abstract
- Exposure to uranium via ingestion of edible products may lead to serious health hazards when taken in quantities more than recommended limit. Hence, to assess the uranium content in groundwater and concerned health hazards 64 groundwater samples were collected from Hamirpur and Mandi districts of Himachal Pradesh. The samples were collected in pre monsoon season from the handpumps and bowries. The region lies in Lower Himalayan range which is storehouse of various granatic rocks. Presence of uranium deposits in Tileli (Mandi), Rajpura (Una), Lambehra (Hamirpur) makes the area more vulnerable for the study. The groundwater samples were analysed to measure concentration of uranium using LED Fluorimeter developed by Quantalase Private. Limited. The uranium concentration in groundwater samples varied from 0.25 to 17.29 & mu;g L-1, with an average value of 1.97. Uranium concentration in none of the samples surpassed the limit of 30 & mu;g L-1 recommended by WHO(2011), 60 & mu;g L-1 set by AERB(2004). Health risks were estimated in terms radiological and chemical toxicity for different isotopes of uranium. The calculated average mortality and morbidity risks were lower than the actual prescribed limit. The average Lifetime Average Daily Dose (LADD) was calculated as 0.04 and Hazard Quotient (HQ) below unity. Annual ingestion doses for different age groups were also measured which lies under safe limit. Thus, it is recommended that the groundwater is safe for consumption by public. Using Hair Compartment Model for uranium and mean daily uranium intake of 2.71 & mu;g for 60-year exposure period, organ specific doses due to uranium radioisotopes in prime organs/tissues and excretion rates via urine, faeces and hair pathway are estimated.
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7. |
- Abolfathi, Bela, et al.
(author)
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The Fourteenth Data Release of the Sloan Digital Sky Survey : First Spectroscopic Data from the Extended Baryon Oscillation Spectroscopic Survey and from the Second Phase of the Apache Point Observatory Galactic Evolution Experiment
- 2018
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In: Astrophysical Journal Supplement Series. - : IOP Publishing Ltd. - 0067-0049 .- 1538-4365. ; 235:2
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Journal article (peer-reviewed)abstract
- The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since 2014 July. This paper describes the second data release from this phase, and the 14th from SDSS overall (making this Data Release Fourteen or DR14). This release makes the data taken by SDSS-IV in its first two years of operation (2014-2016 July) public. Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey; the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data-driven machine-learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from the SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS web site (www.sdss.org) has been updated for this release and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020 and will be followed by SDSS-V.
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8. |
- Agarwal, Abhishek, et al.
(author)
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Higher charges in dynamical spin chains for SYM theory
- 2005
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In: Journal of High Energy Physics. - : Springer Science and Business Media LLC. - 1029-8479 .- 1126-6708. ; :10, s. 1291-1302
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Journal article (peer-reviewed)abstract
- We construct, to the first two non-trivial orders, the next conserved charge in the su(2|3) sector of N=4 Super Yang-Mills theory. This represents a test of integrability in a sector where the interactions change the number of sites of the chain. The expression for the charge is completely determined by the algebra and can be written in a diagrammatic form in terms of the interactions already present in the Hamiltonian. It appears likely that this diagrammatic expression remains valid in the full theory and can be generalized to higher loops and higher charges thus helping in establishing complete integrability for these dynamical chains.
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9. |
- Agarwal, Abhishek, et al.
(author)
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Scattering amplitudes of massive N = 2 gauge theories in three dimensions
- 2014
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In: Physical Review D. - 1550-7998 .- 1550-2368. ; 89:4, s. 045020-
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Journal article (peer-reviewed)abstract
- We study the scattering amplitudes of mass-deformed Chern-Simons theories and Yang-Mills-Chern-Simons theories with N = 2 supersymmetry in three dimensions. In particular, we derive the on-shell supersymmetry algebras which underlie the scattering matrices of these theories. We then compute various 3 and 4-point on-shell tree-level amplitudes in these theories. For the mass-deformed Chern-Simons theory, odd-point amplitudes vanish and we find that all of the 4-point amplitudes can be encoded elegantly in superamplitudes. For the Yang-Mills-Chern-Simons theory, we obtain all of the 4-point tree-level amplitudes using a combination of perturbative techniques and algebraic constraints and we comment on difficulties related to computing amplitudes with external gauge fields using Feynman diagrams. Finally, we propose a Britto-Cachazo-Feng-Witten recursion relation for mass-deformed theories in three dimensions and discuss the applicability of this proposal to mass-deformed N = 2 theories.
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10. |
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11. |
- Agarwala, Sunita, et al.
(author)
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Convolutional Neural Networks for Efficient Localization of Interstitial Lung Disease Patterns in HRCT Images
- 2018
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In: Medical Image Understanding and Analysis. - Cham : Springer Nature. - 9783319959214 - 9783319959207 ; , s. 12-22
-
Conference paper (peer-reviewed)abstract
- Lung field segmentation is the first step towards the development of any computer aided diagnosis (CAD) system for interstitial lung diseases (ILD) observed in chest high resolution computed tomography (HRCT) images. If the segmentation is not done efficiently it will compromise the accuracy of CAD system. In this paper, a deep learning-based method is proposed to localize several interstitial lung disease patterns (ILD) in HRCT images without performing lung field segmentation. In this paper, localization of several ILD patterns is performed in image slice. The pretrained models of ZF and VGG networks were fine-tuned in order to localize ILD patterns using Faster R-CNN framework. The three most difficult ILD patterns consolidation, emphysema, and fibrosis have been used for this study and the accuracy of the method has been evaluated in terms of mean average precision (mAP) and free receiver operating characteristic (FROC) curve. The model achieved mAP value of 75% and 83% on ZF and VGG networks, respectively. The result obtained shows the effectiveness of the method in the localization of different ILD patterns.
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12. |
- Agrawal, Mridul, et al.
(author)
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TET2-mutant clonal hematopoiesis and risk of gout
- 2022
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In: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 140:10, s. 1094-1103
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Journal article (peer-reviewed)abstract
- Gout is a common inflammatory arthritis caused by precipitation of monosodium urate (MSU) crystals in individuals with hyperuricemia. Acute flares are accompanied by secretion of proinflammatory cytokines, including interleukin-1β (IL-1β). Clonal hematopoiesis of indeterminate potential (CHIP) is an age-related condition predisposing to hematologic cancers and cardiovascular disease. CHIP is associated with elevated IL-1β, thus we investigated CHIP as a risk factor for gout. To test the clinical association between CHIP and gout, we analyzed whole exome sequencing data from 177 824 individuals in the MGB Biobank (MGBB) and UK Biobank (UKB). In both cohorts, the frequency of gout was higher among individuals with CHIP than without CHIP (MGBB, CHIP with variant allele fraction [VAF] ≥2%: odds ratio [OR], 1.69; 95% CI, 1.09-2.61; P = .0189; UKB, CHIP with VAF ≥10%: OR, 1.25; 95% CI, 1.05-1.50; P = .0133). Moreover, individuals with CHIP and a VAF ≥10% had an increased risk of incident gout (UKB: hazard ratio [HR], 1.28; 95% CI, 1.06-1.55; P = .0107). In murine models of gout pathogenesis, animals with Tet2 knockout hematopoietic cells had exaggerated IL-1β secretion and paw edema upon administration of MSU crystals. Tet2 knockout macrophages elaborated higher levels of IL-1β in response to MSU crystals in vitro, which was ameliorated through genetic and pharmacologic Nlrp3 inflammasome inhibition. These studies show that TET2-mutant CHIP is associated with an increased risk of gout in humans and that MSU crystals lead to elevated IL-1β levels in Tet2 knockout murine models. We identify CHIP as an amplifier of NLRP3-dependent inflammatory responses to MSU crystals in patients with gout.
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13. |
- Aguado, D. S., et al.
(author)
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The Fifteenth Data Release of the Sloan Digital Sky Surveys : First Release of MaNGA-derived Quantities, Data Visualization Tools, and Stellar Library
- 2019
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In: Astrophysical Journal Supplement Series. - : Institute of Physics Publishing (IOPP). - 0067-0049 .- 1538-4365. ; 240:2
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Journal article (peer-reviewed)abstract
- Twenty years have passed since first light for the Sloan Digital Sky Survey (SDSS). Here, we release data taken by the fourth phase of SDSS (SDSS-IV) across its first three years of operation (2014 July-2017 July). This is the third data release for SDSS-IV, and the 15th from SDSS (Data Release Fifteen; DR15). New data come from MaNGA-we release 4824 data cubes, as well as the first stellar spectra in the MaNGA Stellar Library (MaStar), the first set of survey-supported analysis products (e.g., stellar and gas kinematics, emission-line and other maps) from the MaNGA Data Analysis Pipeline, and a new data visualization and access tool we call "Marvin." The next data release, DR16, will include new data from both APOGEE-2 and eBOSS; those surveys release no new data here, but we document updates and corrections to their data processing pipelines. The release is cumulative; it also includes the most recent reductions and calibrations of all data taken by SDSS since first light. In this paper, we describe the location and format of the data and tools and cite technical references describing how it was obtained and processed. The SDSS website (www.sdss.org) has also been updated, providing links to data downloads, tutorials, and examples of data use. Although SDSS-IV will continue to collect astronomical data until 2020, and will be followed by SDSS-V (2020-2025), we end this paper by describing plans to ensure the sustainability of the SDSS data archive for many years beyond the collection of data.
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14. |
- Ahmed, Md Estak, et al.
(author)
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A Bidirectional Bioinspired [FeFe]-Hydrogenase Model
- 2022
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In: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 144:8, s. 3614-3625
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Journal article (peer-reviewed)abstract
- With the price-competitiveness of solar and wind power, hydrogen technologies may be game changers for a cleaner, defossilized, and sustainable energy future. H-2 can indeed be produced in electrolyzers from water, stored for long periods, and converted back into power, on demand, in fuel cells. The feasibility of the latter process critically depends on the discovery of cheap and efficient catalysts able to replace platinum group metals at the anode and cathode of fuel cells. Bioinspiration can be key for designing such alternative catalysts. Here we show that a novel class of iron-based catalysts inspired from the active site of [FeFe]-hydrogenase behave as unprecedented bidirectional electrocatalysts for interconverting H-2 and protons efficiently under near-neutral aqueous conditions. Such bioinspired catalysts have been implemented at the anode of a functional membrane-less H-2/O-2 fuel cell device.
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15. |
- Ajore, Ram, et al.
(author)
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Functional dissection of inherited non-coding variation influencing multiple myeloma risk
- 2022
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
-
Journal article (peer-reviewed)abstract
- Thousands of non-coding variants have been associated with increased risk of human diseases, yet the causal variants and their mechanisms-of-action remain obscure. In an integrative study combining massively parallel reporter assays (MPRA), expression analyses (eQTL, meQTL, PCHiC) and chromatin accessibility analyses in primary cells (caQTL), we investigate 1,039 variants associated with multiple myeloma (MM). We demonstrate that MM susceptibility is mediated by gene-regulatory changes in plasma cells and B-cells, and identify putative causal variants at six risk loci (SMARCD3, WAC, ELL2, CDCA7L, CEP120, and PREX1). Notably, three of these variants co-localize with significant plasma cell caQTLs, signaling the presence of causal activity at these precise genomic positions in an endogenous chromosomal context in vivo. Our results provide a systematic functional dissection of risk loci for a hematologic malignancy.
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16. |
- Akiyama, Kazunori, et al.
(author)
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First M87 Event Horizon Telescope Results. IX. Detection of Near-horizon Circular Polarization
- 2023
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In: Astrophysical Journal Letters. - 2041-8213 .- 2041-8205. ; 957:2
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Journal article (peer-reviewed)abstract
- Event Horizon Telescope (EHT) observations have revealed a bright ring of emission around the supermassive black hole at the center of the M87 galaxy. EHT images in linear polarization have further identified a coherent spiral pattern around the black hole, produced from ordered magnetic fields threading the emitting plasma. Here we present the first analysis of circular polarization using EHT data, acquired in 2017, which can potentially provide additional insights into the magnetic fields and plasma composition near the black hole. Interferometric closure quantities provide convincing evidence for the presence of circularly polarized emission on event-horizon scales. We produce images of the circular polarization using both traditional and newly developed methods. All methods find a moderate level of resolved circular polarization across the image (〈|v|〉 < 3.7%), consistent with the low image-integrated circular polarization fraction measured by the Atacama Large Millimeter/submillimeter Array (|vint| < 1%). Despite this broad agreement, the methods show substantial variation in the morphology of the circularly polarized emission, indicating that our conclusions are strongly dependent on the imaging assumptions because of the limited baseline coverage, uncertain telescope gain calibration, and weakly polarized signal. We include this upper limit in an updated comparison to general relativistic magnetohydrodynamic simulation models. This analysis reinforces the previously reported preference for magnetically arrested accretion flow models. We find that most simulations naturally produce a low level of circular polarization consistent with our upper limit and that Faraday conversion is likely the dominant production mechanism for circular polarization at 230 GHz in M87*
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17. |
- Akiyama, Kazunori, et al.
(author)
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First Sagittarius A∗ Event Horizon Telescope Results. VII. Polarization of the Ring
- 2024
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In: Astrophysical Journal Letters. - 2041-8213 .- 2041-8205. ; 964:2
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Journal article (peer-reviewed)abstract
- The Event Horizon Telescope observed the horizon-scale synchrotron emission region around the Galactic center supermassive black hole, Sagittarius A∗ (Sgr A∗), in 2017. These observations revealed a bright, thick ring morphology with a diameter of 51.8 ± 2.3 μas and modest azimuthal brightness asymmetry, consistent with the expected appearance of a black hole with mass M≈ 4 × 106 M⊙. From these observations, we present the first resolved linear and circular polarimetric images of Sgr A∗. The linear polarization images demonstrate that the emission ring is highly polarized, exhibiting a prominent spiral electric vector polarization angle pattern with a peak fractional polarization of ∼40% in the western portion of the ring. The circular polarization images feature a modestly (∼5%°-10%) polarized dipole structure along the emission ring, with negative circular polarization in the western region and positive circular polarization in the eastern region, although our methods exhibit stronger disagreement than for linear polarization. We analyze the data using multiple independent imaging and modeling methods, each of which is validated using a standardized suite of synthetic data sets. While the detailed spatial distribution of the linear polarization along the ring remains uncertain owing to the intrinsic variability of the source, the spiraling polarization structure is robust to methodological choices. The degree and orientation of the linear polarization provide stringent constraints for the black hole and its surrounding magnetic fields, which we discuss in an accompanying publication.
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18. |
- Akiyama, Kazunori, et al.
(author)
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First Sagittarius A∗ Event Horizon Telescope Results. VIII. Physical Interpretation of the Polarized Ring
- 2024
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In: Astrophysical Journal Letters. - 2041-8213 .- 2041-8205. ; 964:2
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Journal article (peer-reviewed)abstract
- In a companion paper, we present the first spatially resolved polarized image of Sagittarius A∗ on event horizon scales, captured using the Event Horizon Telescope, a global very long baseline interferometric array operating at a wavelength of 1.3 mm. Here we interpret this image using both simple analytic models and numerical general relativistic magnetohydrodynamic (GRMHD) simulations. The large spatially resolved linear polarization fraction (24%-28%, peaking at ∼40%) is the most stringent constraint on parameter space, disfavoring models that are too Faraday depolarized. Similar to our studies of M87∗, polarimetric constraints reinforce a preference for GRMHD models with dynamically important magnetic fields. Although the spiral morphology of the polarization pattern is known to constrain the spin and inclination angle, the time-variable rotation measure (RM) of Sgr A∗ (equivalent to ≈ 46° ± 12° rotation at 228 GHz) limits its present utility as a constraint. If we attribute the RM to internal Faraday rotation, then the motion of accreting material is inferred to be counterclockwise, contrary to inferences based on historical polarized flares, and no model satisfies all polarimetric and total intensity constraints. On the other hand, if we attribute the mean RM to an external Faraday screen, then the motion of accreting material is inferred to be clockwise, and one model passes all applied total intensity and polarimetric constraints: a model with strong magnetic fields, a spin parameter of 0.94, and an inclination of 150°. We discuss how future 345 GHz and dynamical imaging will mitigate our present uncertainties and provide additional constraints on the black hole and its accretion flow.
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19. |
- Akiyama, Kazunori, et al.
(author)
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The persistent shadow of the supermassive black hole of M 87: I. Observations, calibration, imaging, and analysis*
- 2024
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In: Astronomy and Astrophysics. - 0004-6361 .- 1432-0746. ; 681
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Journal article (peer-reviewed)abstract
- In April 2019, the Event Horizon Telescope (EHT) Collaboration reported the first-ever event-horizon-scale images of a black hole, resolving the central compact radio source in the giant elliptical galaxy M 87. These images reveal a ring with a southerly brightness distribution and a diameter of ∼42 μas, consistent with the predicted size and shape of a shadow produced by the gravitationally lensed emission around a supermassive black hole. These results were obtained as part of the April 2017 EHT observation campaign, using a global very long baseline interferometric radio array operating at a wavelength of 1.3 mm. Here, we present results based on the second EHT observing campaign, taking place in April 2018 with an improved array, wider frequency coverage, and increased bandwidth. In particular, the additional baselines provided by the Greenland telescope improved the coverage of the array. Multiyear EHT observations provide independent snapshots of the horizon-scale emission, allowing us to confirm the persistence, size, and shape of the black hole shadow, and constrain the intrinsic structural variability of the accretion flow. We have confirmed the presence of an asymmetric ring structure, brighter in the southwest, with a median diameter of 43.3-3.1+1.5 μas. The diameter of the 2018 ring is remarkably consistent with the diameter obtained from the previous 2017 observations. On the other hand, the position angle of the brightness asymmetry in 2018 is shifted by about 30 relative to 2017. The perennial persistence of the ring and its diameter robustly support the interpretation that the ring is formed by lensed emission surrounding a Kerr black hole with a mass ∼6.5× 109M. The significant change in the ring brightness asymmetry implies a spin axis that is more consistent with the position angle of the large-scale jet.
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20. |
- Alam, Mahmood, et al.
(author)
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Performance analysis of microchannel heat sink with ribbed pinfins
- 2024
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In: International Journal of Heat and Fluid Flow. - : Elsevier BV. - 0142-727X .- 1879-2278. ; 109
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Journal article (peer-reviewed)abstract
- This paper presents a numerical study investigating the effect of ribbed pinfins on the thermal–hydraulic performance of a microchannel heat sink. A three-dimensional numerical model of a single rectangular microchannel with rectangular pinfins having ribs on them is developed, and simulations are performed for different rib configurations under laminar flow conditions with deionized water as the coolant. The study is conducted in two parts. The first part examines the influence of varying numbers of ribs on the pinfins while maintaining a constant rib width. The results show that increasing the number of ribs initially enhances heat transfer, with the case having two ribs (R2) exhibiting the highest Nusselt number ratio and lowest thermal resistance, up to 16 % lower than the nonribbed case (R0). However, a further increase in the number of ribs leads to a decrease in heat transfer performance due to the reduced cross-sectional area for heat conduction through the ribs. Moreover, the highest performance factor is exhibited by the case consisting of seven ribs (R7). The second part explores the impact of varying rib width, using the optimal R7 configuration based on the performance factor from the first part. The results indicate that increasing the rib width significantly improves heat transfer, with the widest rib case (W7) achieving up to a 25 % increase in Nusselt number compared to a plain microchannel. The study provides insights into the design of efficient microchannel heat sinks with ribbed pinfins for effective cooling of high-heat-flux electronic devices.
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21. |
- Ali, Mina, et al.
(author)
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The multiple myeloma risk allele at 5q15 lowers ELL2 expression and increases ribosomal gene expression
- 2018
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In: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 9:1, s. 1649-
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Journal article (peer-reviewed)abstract
- Recently, we identified ELL2 as a susceptibility gene for multiple myeloma (MM). To understand its mechanism of action, we performed expression quantitative trait locus analysis in CD138+ plasma cells from 1630 MM patients from four populations. We show that the MM risk allele lowers ELL2 expression in these cells (Pcombined = 2.5 × 10−27; βcombined = −0.24 SD), but not in peripheral blood or other tissues. Consistent with this, several variants representing the MM risk allele map to regulatory genomic regions, and three yield reduced transcriptional activity in plasmocytoma cell lines. One of these (rs3777189-C) co-locates with the best-supported lead variants for ELL2 expression and MM risk, and reduces binding of MAFF/G/K family transcription factors. Moreover, further analysis reveals that the MM risk allele associates with upregulation of gene sets related to ribosome biogenesis, and knockout/knockdown and rescue experiments in plasmocytoma cell lines support a cause–effect relationship. Our results provide mechanistic insight into MM predisposition.
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22. |
- Allgöwer, Friederike, et al.
(author)
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Modified Chlorophyll Pigment at ChlD1 Tunes Photosystem II Beyond the Red-Light Limit
-
Other publication (other academic/artistic)abstract
- Photosystem II (PSII) is powered by the light-capturing properties of chlorophyll a pigments that define the spectral range of oxygenic photosynthesis. Some photosynthetic cyanobacteria can acclimate to growth in longer wavelength light by replacing five chlorophylls for long wavelength pigments in specific locations, including one in the reaction center (RC). However, the exact location and the nature of this long wavelength pigment still remain uncertain. Here we have addressed the color-tuning mechanism of the far-red light PSII (FRL-PSII) by excited state calculations at both the ab initio correlated (ADC2) and linear-response time-dependent density functional theory (LR-TDDFT) levels in combination with large-scale hybrid quantum/classical (QM/MM) simulations and atomistic molecular dynamics. We show that substitution of a single chlorophyll pigment (ChlD1) at the RC by chlorophyll d leads to a spectral shift beyond the far-red light limit, as a result of the protein electrostatic, polarization and electronic coupling effects that reproduce key structural and spectroscopic observations. Pigment substitution at the ChlD1 site further results in a low site energy within the RC that could function as a sink for the excitation energy and initiate the primary charge separation reaction, driving the water oxidation. Our findings provide a basis for understanding color-tuning mechanisms and bioenergetic principles of oxygenic photosynthesis at the far-red light limit.
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23. |
- Andersson, Erika, et al.
(author)
-
Generation and properties of organic colloids extracted by water from the organic horizon of a boreal forest soil
- 2023
-
In: Geoderma. - : Elsevier BV. - 0016-7061. ; 432
-
Journal article (peer-reviewed)abstract
- Organic colloids are an important part of dissolved organic matter (DOM) yet many of their properties remain elusive. The main aims of this study were to assess how the colloidal properties of DOM extracted with water from an organic boreal soil horizon varied with the extraction protocol, and thereby provide insight into the nature of the DOM colloids and develop a mechanistic understanding of how the colloids were generated from the parent soil aggregates. This was accomplished by systematic variations of extraction temperature (4 °C–100 °C), time, mechanical agitation, and pH, together with a combination of chemical analyses, and light and X-ray scattering. Our results agreed with the previous identification of two main colloidal DOM species, one fractal cluster and a second, smaller colloidal DOM species described as chains or coils. Fractal clusters completely dominated the colloidal DOM in extracts from our soil at room temperature and below. Colloidal coils only existed in DOM extracted above room temperature, and their amount increased significantly between 50 °C–100 °C. Moreover, the temperature variation indicated that the fractal clusters partly dissolved into colloidal coils at elevated temperatures. Mechanical agitation at 4 °C significantly increased the amount of DOM extracted, increasing the concentrations of both fractal clusters and low-molecular weight organic compounds. While the clusters were extracted from agitated and non-agitated soil suspensions, the low molecular weight organics were mainly released by agitation. Based on the experimental observations, we propose a conceptual model where parent soil aggregates contain the fractal clusters in mobile and occluded forms, and that the occluded clusters co-exist with occluded low molecular weight organics. These occluded forms may be released by mechanical forces, increasing pH and temperature. At higher temperatures, the soil aggregates and the fractal clusters start to break up, and subsequently individual colloidal coils, presumably carbohydrates, disperse in the water phase. The model explains the origin and properties of the fractal clusters that completely dominate the colloidal DOM extracted from our soil at room temperature and below.
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24. |
- Andres, Blanca, et al.
(author)
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Response of stone wool–insulated building barriers under severe heating exposures
- 2018
-
In: Journal of Fire Sciences. - : SAGE Publications. - 0734-9041 .- 1530-8049. ; 36:4, s. 315-341
-
Journal article (peer-reviewed)abstract
- This article presents the experimental results of stone wool–layered sandwich constructions, with either steel or gypsum claddings, tested under four different heating exposures: 7 kW/m2 incident radiant heat flux exposure, 60 kW/m2 incident radiant heat flux exposure, parametric time–temperature curve exposure and ISO 834 standard time–temperature exposure. The test apparatus used were a movable radiant panel system, a mid-scale furnace (1.5 m3) and a large-scale furnace (15 m3). The results show that reduced-scale tests are capable of reproducing the heat transferred through the construction at large scale provided there is limited mechanical degradation. The results indicate that the availability of oxygen is fundamental to the fire behaviour of the sandwich composites tested. Reactions occurring in stone wool micro-scale testing, such as oxidative combustion of the binder or crystallisation of the fibres, have a limited effect on the temperature increase when wool is protected from air entrainment.
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25. |
- Anil Kumar, Puri, et al.
(author)
-
Magnetic polarons and spin-glass behavior in insulating La1-xSrxCoO3 (x = 0.125 and 0.15)
- 2020
-
In: Physical Review Research. - : AMER PHYSICAL SOC. - 2643-1564. ; 2:4
-
Journal article (peer-reviewed)abstract
- The evolution of magnetic polarons in Sr doped LaCoO3 (La1-xSrxCoO3) single crystal and polycrystalline samples are investigated by employing dc and ac magnetic measurement and small angle neutron scattering (SANS) techniques. The effect of magnetic field and temperature on magnetic polarons is experimentally studied for La0.875Sr0.125CoO3 and La0.85Sr0.15CoO3 compounds that belong to the spin glass insulating regime of the broader compositional phase diagram of this system. Langevin analyses of the isothermal magnetization curves in the notional paramagnetic regime prove the existence of magnetic polarons with large moments. The dc field superimposed ac susceptibility data and the analysis of the glassy dynamics prove that the size of polarons in 15% Sr doped crystal increase as the field is increased while the field effect is not visible in the 12.5% Sr doped crystal. A polycrystalline sample of La0.85Sr0.15CoO3 is analyzed by SANS experiments, which confirm nonzero correlation length at temperatures far above the macroscopic ordering temperature and hence the presence of magnetic polarons.
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26. |
- Anjo, J., et al.
(author)
-
Modeling the long-term impact of demand response in energy planning : The Portuguese electric system case study
- 2018
-
In: Energy. - : Elsevier Ltd. - 0360-5442 .- 1873-6785. ; 165, s. 456-468
-
Journal article (peer-reviewed)abstract
- With the urge to decrease carbon emissions, electricity systems need to evolve to promote the integration of renewable resources and end-use energy efficiency. Demand Response (DR) can be used as a strategy, one among many, to improve the balance between demand and supply of electricity, especially in systems that rely heavily on variable energy renewable resources. Thus, it is important to understand up to what extent a countrywide system would cope with DR implementation. In this work, the impact of demand response in the long-term is assessed, using a model of the Portuguese electricity system in the modeling tool OSeMOSYS. The theoretical potential of DR is computed to understand better the impact on the overall system planning, by analyzing three scenarios – a business as usual scenario, a carbon-free system scenario in 2050, and a scenario without heavy carbon emission restrictions. DR impact in all three scenarios results in a decrease in the overall costs, on the capacity installed and in an increase in the percentage of renewable capacity. Further, an economic analysis showed that DR would take 15 years, on average, to influence the average electricity cost and that the reduction in total costs is mainly due to the avoided capacity investments.
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27. |
- Arpaia, Riccardo, 1985, et al.
(author)
-
Signature of quantum criticality in cuprates by charge density fluctuations
- 2023
-
In: Nature Communications. - 2041-1723 .- 2041-1723. ; 14:1
-
Journal article (peer-reviewed)abstract
- The universality of the strange metal phase in many quantum materials is often attributed to the presence of a quantum critical point (QCP), a zero-temperature phase transition ruled by quantum fluctuations. In cuprates, where superconductivity hinders direct QCP observation, indirect evidence comes from the identification of fluctuations compatible with the strange metal phase. Here we show that the recently discovered charge density fluctuations (CDF) possess the right properties to be associated to a quantum phase transition. Using resonant x-ray scattering, we studied the CDF in two families of cuprate superconductors across a wide doping range (up to p = 0.22). At p* ≈ 0.19, the putative QCP, the CDF intensity peaks, and the characteristic energy Δ is minimum, marking a wedge-shaped region in the phase diagram indicative of a quantum critical behavior, albeit with anomalies. These findings strengthen the role of charge order in explaining strange metal phenomenology and provide insights into high-temperature superconductivity.
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28. |
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29. |
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30. |
- Baruah, Sanjoy, et al.
(author)
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Fixed-Parameter Analysis of Preemptive Uniprocessor Scheduling Problems
- 2022
-
In: 2022 IEEE Real-Time Systems Symposium (RTSS 2022). - : Institute of Electrical and Electronics Engineers (IEEE). - 9781665453462 - 9781665453479 ; , s. 185-196
-
Conference paper (peer-reviewed)abstract
- The algorithmic technique of fixed-parameter analysis of computationally intractable problems seeks to obtain a deeper understanding of the underlying causes of the intractability, with a view to identifying conditions under which the problem becomes tractable. We apply fixed-parameter analysis to the fixed-priority and EDF scheduling of recurrent (periodic and sporadic) task systems upon preemptive uniprocessor platforms.
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31. |
- Belanger, Genevieve, et al.
(author)
-
WIMP and FIMP dark matter in singlet-triplet fermionic model
- 2022
-
In: Journal of High Energy Physics (JHEP). - : Springer Nature. - 1126-6708 .- 1029-8479. ; :11
-
Journal article (peer-reviewed)abstract
- We present an extension of the SM involving three triplet fermions, one triplet scalar and one singlet fermion, which can explain both neutrino masses and dark matter. One triplet of fermions and the singlet are odd under a Z(2) symmetry, thus the model features two possible dark matter candidates. The two remaining Z(2)-even triplet fermions can reproduce the neutrino masses and oscillation parameters consistent with observations. We consider the case where the singlet has feeble couplings while the triplet is weakly interacting and investigate the different possibilities for reproducing the observed dark matter relic density. This includes production of the triplet WIMP from freeze-out and from decay of the singlet as well as freeze-in production of the singlet from decay of particles that belong to the thermal bath or are thermally decoupled. While freeze-in production is usually dominated by decay processes, we also show cases where the annihilation of bath particles give substantial contribution to the final relic density. This occurs when the new scalars are below the TeV scale, thus in the reach of the LHC. The next-to-lightest odd particle can be long-lived and can alter the successful BBN predictions for the abundance of light elements, these constraints are relevant in both the scenarios where the singlet or the triplet are the long-lived particle. In the case where the triplet is the DM, the model is subject to constraints from ongoing direct, indirect and collider experiments. When the singlet is the DM, the triplet which is the next-to-lightest odd particle can be long-lived and can be probed at the proposed MATHUSLA detector. Finally we also address the detection prospects of triplet fermions and scalars at the LHC.
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32. |
- Bélanger, Geneviève, et al.
(author)
-
WIMP and FIMP dark matter in singlet-triplet fermionic model
- 2022
-
In: Journal of High Energy Physics (JHEP). - : Springer Nature. - 1126-6708 .- 1029-8479. ; 2022:11
-
Journal article (peer-reviewed)abstract
- We present an extension of the SM involving three triplet fermions, one triplet scalar and one singlet fermion, which can explain both neutrino masses and dark matter. One triplet of fermions and the singlet are odd under a Z2 symmetry, thus the model features two possible dark matter candidates. The two remaining Z2-even triplet fermions can reproduce the neutrino masses and oscillation parameters consistent with observations. We consider the case where the singlet has feeble couplings while the triplet is weakly interacting and investigate the different possibilities for reproducing the observed dark matter relic density. This includes production of the triplet WIMP from freeze-out and from decay of the singlet as well as freeze-in production of the singlet from decay of particles that belong to the thermal bath or are thermally decoupled. While freeze-in production is usually dominated by decay processes, we also show cases where the annihilation of bath particles give substantial contribution to the final relic density. This occurs when the new scalars are below the TeV scale, thus in the reach of the LHC. The next-to-lightest odd particle can be long-lived and can alter the successful BBN predictions for the abundance of light elements, these constraints are relevant in both the scenarios where the singlet or the triplet are the long-lived particle. In the case where the triplet is the DM, the model is subject to constraints from ongoing direct, indirect and collider experiments. When the singlet is the DM, the triplet which is the next-to-lightest odd particle can be long-lived and can be probed at the proposed MATHUSLA detector. Finally we also address the detection prospects of triplet fermions and scalars at the LHC.
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33. |
- Bélanger, Geneviève, et al.
(author)
-
WIMP and FIMP Dark Matter in Singlet-Triplet Fermionic Model
- 2024
-
In: Proceedings of the XXV DAE-BRNS High Energy Physics (HEP) Symposium 2022. - : Springer Science and Business Media Deutschland GmbH. ; , s. 79-83
-
Conference paper (peer-reviewed)abstract
- We present an extension of the SM involving three triplet fermions, one triplet scalar and one singlet fermion, which can explain both neutrino masses and dark matter. One triplet of fermions and the singlet are odd under a Z2 symmetry, thus the model features two possible dark matter candidates. The two remaining Z2-even triplet fermions can reproduce the neutrino masses and oscillation parameters consistent with observations. We consider the case where the singlet has feeble couplings while the triplet is weakly interacting and investigate the different possibilities for reproducing the observed dark matter relic density. This includes production of the triplet WIMP from freeze-out and from decay of the singlet as well as freeze-in production of the singlet from decay of particles that belong to the thermal bath or are thermally decoupled. While freeze-in production is usually dominated by decay processes, we also show cases where the annihilation of bath particles give substantial contribution to the final relic density. This occurs when the new scalars are below the TeV scale, thus in the reach of the LHC. The next-to-lightest odd particle can be long-lived and can alter the successful BBN predictions for the abundance of light elements, these constraints are relevant in both the scenarios where the singlet or the triplet are the long-lived particle.In the case where the triplet is the DM, the model is subject to constraints from ongoing direct, indirect and collider experiments. When the singlet is the DM, the triplet which is the next-to-lightest odd particle can be long-lived and can be probed at the proposed MATHUSLA detector. Finally we also address the detection prospects of triplet fermions and scalars at the LHC.
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34. |
- Berger, Karin, et al.
(author)
-
Xylooligosaccharides Increase Bifidobacteria and Lachnospiraceae in Mice on a High-Fat Diet, with a Concomitant Increase in Short-Chain Fatty Acids, Especially Butyric Acid
- 2021
-
In: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 69:12, s. 3617-3625
-
Journal article (peer-reviewed)abstract
- Effects of xylooligosaccharides (XOSs) as well as a mixture of XOS, inulin, oligofructose, and partially hydrolyzed guar gum (MIX) in mice fed a high-fat diet (HFD) were studied. Control groups were fed an HFD or a low-fat diet. Special attention was paid to the cecal composition of the gut microbiota and formation of short-chain fatty acids, but metabolic parameters were also documented. The XOS group had significantly higher cecum levels of acetic, propionic, and butyric acids than the HFD group, and the butyric acid content was higher in the XOS than in the MIX group. The cecum microbiota of the XOS group contained more Bifidobacteria, Lachnospiraceae, and S24-7 bacteria than the HFD group. A tendency of lower body weight gain was observed on comparing the XOS and HFD groups. In conclusion, the XOS was shown to be a promising prebiotic candidate. The fiber diversity in the MIX diet did not provide any advantages compared to the XOS diet.
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35. |
- Bernardin, Evans, et al.
(author)
-
Development of an all-SiC neuronal interface device
- 2016
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In: MRS Advances. - : Cambridge University Press. - 2059-8521. ; 1:55, s. 3679-3684
-
Journal article (peer-reviewed)abstract
- The intracortical neural interface (INI) is a key component of brain machine interfaces (BMI) which offer the possibility to restore functions lost by patients due to severe trauma to the central or peripheral nervous system. Unfortunately today’s neural electrodes suffer from a variety of design flaws, mainly the use of non-biocompatible materials based on Si or W with polymer coatings to mask the underlying material. Silicon carbide (SiC) is a semiconductor that has been proven to be highly biocompatible, and this chemically inert, physically robust material system may provide the longevity and reliability needed for the INI community. The design, fabrication, and preliminary testing of a prototype all-SiC planar microelectrode array based on 4H-SiC with an amorphous silicon carbide (a-SiC) insulator is described. The fabrication of the planar microelectrode was performed utilizing a series of conventional micromachining steps. Preliminary data is presented which shows a proof of concept for an all-SiC microelectrode device.
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36. |
- Bersani, Marco, et al.
(author)
-
Combined EXAFS, XRD, DRIFTS, and DFT Study of Nano Copper Based Catalysts for CO2 Hydrogenation
- 2016
-
In: ACS Catalysis. - : American Chemical Society (ACS). - 2155-5435. ; 6:9, s. 5823-5833
-
Journal article (peer-reviewed)abstract
- Highly monodispersed CuO nanoparticles (NPs) were synthesized via continuous hydrothermal flow synthesis (CHFS) and then tested as catalysts for CO2 hydrogenation. The catalytic behavior of unsupported 11 nm sized nanoparticles from the same batch was characterized by diffuse reflectance infrared fourier transform spectroscopy (DRIFTS), extended X-ray absorption fine structure (EXAFS), X-ray diffraction (XRD), and catalytic testing, under CO2/H-2 in the temperature range 25-500 degrees C in consistent experimental conditions. This was done to highlight the relationship among structural evolution, surface products, and reaction yields; the experimental results were compared with modeling predictions based on density functional theory (DFT) simulations of the CuO system. In situ DRIFTS revealed the formation of surface formate species at temperatures as low as 70 degrees C. DFT calculations of CO2 hydrogenation on the CuO surface suggested that hydrogenation reduced the CuO surface to Cu2O, which facilitated the formation of formate. In situ EXAFS supported a strong correlation between the Cu2O phase fraction and the formate peak intensity, with the maxima corresponding to where Cu2O was the only detectable phase at 170 degrees C, before the onset of reduction to Cu at 190 degrees C. The concurrent phase and crystallite size evolution were monitored by in situ XRD, which suggested that the CuO NPs were stable in size before the onset of reduction, with smaller Cu2O crystallites being observed from 130 degrees C. Further reduction to Cu from 190 C was followed by a rapid decrease of surface formate and the detection of adsorbed CO from 250 degrees C; these results are in agreement with heterogeneous catalytic tests where surface CO was observed over the same temperature range. Furthermore, CH4 was detected in correspondence with the decomposition of formate and formation of the Cu phase, with a maximum conversion rate of 2.8% measured at 470 degrees C (on completely reduced copper), supporting the indication of independent reaction pathways for the conversion of CO2 to CH4 and CO that was suggested by catalytic tests. The resulting Cu NPs had a final crystallite size of ca. 44 nm at 500 degrees C and retained a significantly active surface.
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37. |
- Bhambri, Aksheev, et al.
(author)
-
Large scale changes in the transcriptome of Eisenia fetida during regeneration
- 2018
-
In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 13:9
-
Journal article (peer-reviewed)abstract
- Earthworms show a wide spectrum of regenerative potential with certain species like Eisenia fetida capable of regenerating more than two-thirds of their body while other closely related species, such as Paranais litoralis seem to have lost this ability. Earthworms belong to the phylum Annelida, in which the genomes of the marine oligochaete Capitella telata and the freshwater leech Helobdella robusta have been sequenced and studied. Herein, we report the transcriptomic changes in Eisenia fetida (Indian isolate) during regeneration. Following injury, E. fetida regenerates the posterior segments in a time spanning several weeks. We analyzed gene expression changes both in the newly regenerating cells and in the adjacent tissue, at early (15days post amputation), intermediate (20days post amputation) and late (30 days post amputation) by RNAseq based de novo assembly and comparison of transcriptomes. We also generated a draft genome sequence of this terrestrial red worm using short reads and mate-pair reads. An in-depth analysis of the miRNome of the worm showed that many miRNA gene families have undergone extensive duplications. Sox4, a master regulator of TGF-beta mediated epithelial-mesenchymal transition was induced in the newly regenerated tissue. Genes for several proteins such as sialidases and neurotrophins were identified amongst the differentially expressed transcripts. The regeneration of the ventral nerve cord was also accompanied by the induction of nerve growth factor and neurofilament genes. We identified 315 novel differentially expressed transcripts in the transcriptome, that have no homolog in any other species. Surprisingly, 82% of these novel differentially expressed transcripts showed poor potential for coding proteins, suggesting that novel ncRNAs may play a critical role in regeneration of earthworm.
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38. |
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39. |
- Bhargava, Abhishek
(author)
-
Fire behaviour of selected polymeric materials : Numerical modelling and validation using microscale and bench scale test methods
- 2020
-
Doctoral thesis (other academic/artistic)abstract
- The ability to predict fire behaviour of materials is of key interest to building materials industry. Themain reason for it is expensive fire testing and certification costs borne by the manufacturers to bring a finished product to market. Failure in a fire test leads to increased expenses in the productdevelopment cycle leading to delayed realization of profits and low cost competitiveness in themarket. Numerical modelling and fire simulations is a less expensive method to predict the outcomesof a real fire test. However, the state of the art models existing in literature suffer from severalshortcomings. A few of them are related to inadequacies related to material property data used inthem as input values. Others include modelling deficiencies pertaining to accurate description ofphysicochemical processes involved in materials during the fire. Often hurdles in implementation ofappropriate numerical methods are also a cause of poor predictability of mathematical models. In this industrial PhD work, a novel one-dimensional computational pyrolysis model was developed using a combination of deterministic and stochastic approach. The tool is capable of prediction of key fire technical properties of interest obtained in a standard cone calorimeter device such as mass loss rate (MLR), heat release rate (HRR), total heat released (THR). The developed model could beincorporated into a bigger CFD code and can be used for estimation of fire growth rate onsuccessively bigger material scale. The performance of novel pyrolysis model considers severalphysicochemical transformation complexities occurring in the material and renders a satisfactoryperformance of the investigated materials on microscale and bench scale level simulations.
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40. |
- Bhargava, Abhishek, et al.
(author)
-
Performance analysis of a heat transfer and sub-grid chemical reaction distributed activation energy model for fire simulations
- 2019
-
In: Journal of Fire Sciences. - : SAGE Publications. - 0734-9041 .- 1530-8049. ; 37:1, s. 18-46
-
Journal article (peer-reviewed)abstract
- A heat transfer and sub-grid chemical reaction kinetic model for solid phase combustion of a charring polymer is presented based on distributed reactivity modeling approach. The model is used to compute flammability parameters of a polymer sheet of a given thickness to simulate test results of a cone calorimeter experiment. Comparison of model simulations with cone calorimeter test data shows that it gives reasonable prediction of mass loss rate, heat release rate, and total heat released of poly-vinyl chloride (PVC) and ethyl vinyl acetate–aluminum tri-hydroxide (EVA-ATH). The solution of governing equations with the current form of distributed reactivity modeling model poses numerical challenges due to appearance of a double integral in the chemical reaction model. Hence, an analytical approximation has been derived to solve mass and energy conservation equations representing the model. Simulation results indicate that with the approximated form of the distributed reactivity modeling model, along with the input parameters retrieved from literature, the model shows comparatively good predictions for EVA-ATH for mass loss rate, heat release rate, and total heat released, but calculates under-predicted values for PVC.
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41. |
- Bhargava, Abhishek, et al.
(author)
-
Pyrolysis modeling of PVC and PMMA using a distributed reactivity model
- 2016
-
In: Polymer Degradation and Stability. - : Elsevier BV. - 0141-3910. ; 129, s. 199-211
-
Journal article (peer-reviewed)abstract
- The thermal decomposition kinetics of poly(vinyl chloride) (PVC) and poly(methyl methacrylate) (PMMA) was studied by thermogravimetry using non isothermal experiments. A detailed kinetic analysis was done using the isoconversional methods (model-free) (including Friedman, Kissinger-Akhaira-Sunose (KAS) and Kissinger methods) and distributed reactivity model (model-fitting). The overall aim was to retrieve kinetic parameters of the model describing the differential thermogravimetric (DTG) curve. For distributed reactivity models, both double and multi-Gaussian methods were used to explain the thermal decomposition process in these polymers. Apparent kinetic parameters were retrieved using optimization calculations with a newly developed computer code using MATLAB® involving pattern search algorithm. Modeling results were compared with the experimental data obtained in a simultaneous thermal analyzer (STA). Agreement between experimental tests and simulations showed good results for fire modeling applications for these polymers.
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42. |
- Bhargava, Abhishek, et al.
(author)
-
Pyrolysis modeling of pvcusing distributed activation energy model-micro scale testing
- 2017
-
In: Proceedings of the International Conference on Applications of Structural Fire Engineering, ASFE 2015. - : Czech Technical University in Prague - Central Library. - 2336-7318. - 9788001061947
-
Conference paper (peer-reviewed)abstract
- Polyvinyl chloride (PVC) is a common thermoplastic whichfinds widespread applications in the construction industry for usage inceiling linings, flooring materials, electrical cables and roofing materials. Several fire requirements are put on these types of applications. For fire safety engineering and product development, thermo-chemical decomposition modeling of PVC isrequired. The FIRETOOLS project investigates the possibilities to predict real scale fire behavior of building products, content and barriers by means of using material data on successively increasing scale. This paper focuses on the material modeling and studiesthe thermo-chemical decomposition of PVC using Distributed Activation Energy Model (DAEM).
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43. |
- Bhattacharya, Abhishek, et al.
(author)
-
Cross-Feeding and Enzymatic Catabolism for Mannan-Oligosaccharide Utilization by the Butyrate-Producing Gut Bacterium Roseburia hominis A2-183
- 2022
-
In: Microorganisms. - : MDPI AG. - 2076-2607. ; 10:12
-
Journal article (peer-reviewed)abstract
- β-Mannan is abundant in the human diet and in hemicellulose derived from softwood. Linear or galactose-substituted β-mannan-oligosaccharides (MOS/GMOSs) derived from β-mannan are considered emerging prebiotics that could stimulate health-associated gut microbiota. However, the underlying mechanisms are not yet resolved. Therefore, this study investigated the cross-feeding and metabolic interactions between Bifidobacterium adolescentis ATCC 15703, an acetate producer, and Roseburia hominis A2-183 DSMZ 16839, a butyrate producer, during utilization of MOS/GMOSs. Cocultivation studies suggest that both strains coexist due to differential MOS/GMOS utilization, along with the cross-feeding of acetate from B. adolescentis E194a to R. hominis A2-183. The data suggest that R. hominis A2-183 efficiently utilizes MOS/GMOS in mono- and cocultivation. Notably, we observed the transcriptional upregulation of certain genes within a dedicated MOS/GMOS utilization locus (RhMosUL), and an exo-oligomannosidase (RhMan113A) gene located distally in the R. hominis A2-183 genome. Significantly, biochemical analysis of β-1,4 mannan-oligosaccharide phosphorylase (RhMOP130A), α-galactosidase (RhGal36A), and exo-oligomannosidase (RhMan113A) suggested their potential synergistic role in the initial utilization of MOS/GMOSs. Thus, our results enhance the understanding of MOS/GMOS utilization by potential health-promoting human gut microbiota and highlight the role of cross-feeding and metabolic interactions between two secondary mannan degraders inhabiting the same ecological niche in the gut.
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44. |
- Bhattacharya, Abhishek, et al.
(author)
-
Enzymatic Conversion of Different Qualities of Refined Softwood Hemicellulose Recovered from Spent Sulfite Liquor
- 2022
-
In: Molecules (Basel, Switzerland). - : MDPI AG. - 1420-3049. ; 27:10
-
Journal article (peer-reviewed)abstract
- Spent sulfite liquor (SSL) from softwood processing is rich in hemicellulose (acetyl galactoglucomannan, AcGGM), lignin, and lignin-derived compounds. We investigated the effect of sequential AcGGM purification on the enzymatic bioconversion of AcGGM. SSL was processed through three consecutive purification steps (membrane filtration, precipitation, and adsorption) to obtain AcGGM with increasing purity. Significant reduction (~99%) in lignin content and modest loss (~18%) of polysaccharides was observed during purification from the least pure preparation (UFR), obtained by membrane filtration, compared to the purest preparation (AD), obtained by adsorption. AcGGM (~14.5 kDa) was the major polysaccharide in the preparations; its enzymatic hydrolysis was assessed by reducing sugar and high-performance anion-exchange chromatography analysis. The hydrolysis of the UFR preparation with Viscozyme L or Trichoderma reesei β-mannanase TrMan5A (1 mg/mL) resulted in less than ~50% bioconversion of AcGGM. The AcGGM in the AD preparation was hydrolyzed to a higher degree (~67% with TrMan5A and 80% with Viscozyme L) and showed the highest conversion rate. This indicates that SSL contains enzyme-inhibitory compounds (e.g., lignin and lignin-derived compounds such as lignosulfonates) which were successfully removed.
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45. |
- Bhattacharya, Abhishek, et al.
(author)
-
Enzyme synergy for the production of arabinoxylo-oligosaccharides from highly substituted arabinoxylan and evaluation of their prebiotic potential
- 2020
-
In: Lebensmittel-Wissenschaft + Technologie. - : Elsevier BV. - 0023-6438 .- 1096-1127. ; 131
-
Journal article (peer-reviewed)abstract
- Wheat bran arabinoxylan can be converted by enzymatic hydrolysis into short arabinoxylo-oligosaccharides (AXOS) with prebiotic potential. Alkali extraction of arabinoxylan from wheat-bran offers advantages in terms of yield and results in arabinoxylan with highly-substituted regions which has been a challenge to hydrolyse using endoxylanases. We show that this hurdle can be overcome by selecting an arabinoxylanase that attacks these regions. The yield of AXOS can be increased by enzyme synergy, involving the hydrolysis of some arabinoxylan side groups. Thus, arabinoxylanase (CtXyl5At) from Clostridium thermocellum, belonging to subfamily 34 of glycoside hydrolase (GH) family 5 was investigated pertaining to its specificity for highly-substituted regions in the arabinoxylan-backbone. CtXyl5At preferentially hydrolysed the water-soluble fraction of alkali-extracted arabinoxylan. AXOS with DP 2-4 were determined as major products from CtXyl5At catalyzed hydrolysis. Increase in AXOS yield was observed with enzyme synergy, involving an initial treatment of soluble arabinoxylan with a GH43 alpha-L-arabinofuranosidase from Bifidobacterium adolescentis termed BaAXHd3 (30 degrees C, 6h), followed by hydrolysis with CtXyl5At (50 degrees C, 24h). The prebiotic potential of AXOS was shown by growth analysis using the human gut bacteria Bifidobacterium adolescentis ATCC 15703 and Roseburia hominis DSM 6839. Importantly, AXOS were utilized by the bacteria and short-chain fatty acids were produced.
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46. |
- Bhattacharya, Arani, et al.
(author)
-
Fast and Efficient Online Selection of Sensors for Transmitter Localization
- 2022
-
In: 2022 14th International Conference on COMmunication Systems and NETworkS, COMSNETS 2022. - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 604-612
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Conference paper (peer-reviewed)abstract
- The increase in cost and usage of RF spectrum has made it increasingly necessary to monitor its usage and protect it from unauthorized use. A number of prior studies have designed algorithms to localize unauthorized transmitters using crowdsourced sensors. To reduce the cost of crowdsourcing, these studies select the most relevant sensors a priori to localize such transmitters. In this work, we instead argue for online selection to localize such transmitters. Online selection can lead to more accurate localization using limited number of sensors, as compared to selecting sensors a priori, albeit at the cost of higher latency. To account for the trade-off between accuracy and latency, we add a constraint on the number of selection rounds. For the case where the number of rounds is equal to the number of selected sensors, we propose a heuristic based on Thompson Sampling and show using trace-driven simulation that it provides 23 % better accuracy compared to a number of proposed baseline algorithms. For restricted number of rounds, we show that using conventional parallel version of the modified Thompson Sampling which selects equal number of sensors in each round results in a substantial reduction in accuracy. To this end, we propose a strategy of selecting decreasing number of sensors in subsequent rounds of the modified Parallel Thompson Sampling. Our evaluation shows that the proposed heuristic leads to only 3 % reduction in accuracy in contrast to 22 % using modified Parallel Thompson Sampling, when we select 50 sensors in 20 rounds.
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47. |
- Bhattacharya, Abhishek, et al.
(author)
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β-Mannanase BoMan26B from Bacteroides ovatus produces mannan-oligosaccharides with prebiotic potential from galactomannan and softwood β-mannans
- 2021
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In: LWT. - : Elsevier BV. - 0023-6438. ; 151
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Journal article (peer-reviewed)abstract
- Galactomannan (GM) in legumes and acetyl-galactoglucomannan (AcGGM) in softwoods are wide-spread β-mannans. Their depolymerisation is catalyzed by β-mannanases. We have investigated a cell-surface exposed and galactose-tolerant β-mannanase (BoMan26B) from the abundant gut bacterium Bacteroides ovatus. Glycosidases from the gut microbiota have potential for production of prebiotics, such as dietary saccharides that would promote beneficial bacteria in the gut. BoMan26B was explored for production of potential prebiotics. Using the above β-mannans as substrate we investigated the product profiles using a herein developed new high-resolution anion-exchange chromatography procedure. The produced linear and galactosyl-decorated β-mannan-oligosaccharides (MOS/GMOS) were mainly of degree of polymerization (DP) 2–6, consistent with the glycan-binding subsites of BoMan26B. Some GM and AcGGM products were acetylated. DP 2–6 MOS were produced at a yield of 30 and 33% (w/w) from GM and AcGGM, respectively. In addition, about as much DP 2–6 GMOS were produced, assessed using guar α-galactosidase as analytical aid. Growth studies using the human gut bacteria Bifidobacterium adolescentis ATCC 15703 (acetate producer) and Roseburia hominis DSMZ 6839 (butyrate producer) revealed significant differences in utilization of specific MOS/GMOS. The prebiotic potential of the MOS/GMOS generated by BoMan26B was further underlined by the observation that both bacterial strains produced short-chain fatty acids.
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48. |
- Bhattacharya, Romit, et al.
(author)
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Clonal Hematopoiesis Is Associated with Higher Risk of Stroke
- 2022
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In: Stroke. - 0039-2499. ; 29:2, s. 788-797
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Journal article (peer-reviewed)abstract
- Background and Purpose: Clonal hematopoiesis of indeterminate potential (CHIP) is a novel age-related risk factor for cardiovascular disease-related morbidity and mortality. The association of CHIP with risk of incident ischemic stroke was reported previously in an exploratory analysis including a small number of incident stroke cases without replication and lack of stroke subphenotyping. The purpose of this study was to discover whether CHIP is a risk factor for ischemic or hemorrhagic stroke. Methods: We utilized plasma genome sequence data of blood DNA to identify CHIP in 78 752 individuals from 8 prospective cohorts and biobanks. We then assessed the association of CHIP and commonly mutated individual CHIP driver genes (DNMT3A, TET2, and ASXL1) with any stroke, ischemic stroke, and hemorrhagic stroke. Results: CHIP was associated with an increased risk of total stroke (hazard ratio, 1.14 [95% CI, 1.03-1.27]; P=0.01) after adjustment for age, sex, and race. We observed associations with CHIP with risk of hemorrhagic stroke (hazard ratio, 1.24 [95% CI, 1.01-1.51]; P=0.04) and with small vessel ischemic stroke subtypes. In gene-specific association results, TET2 showed the strongest association with total stroke and ischemic stroke, whereas DMNT3A and TET2 were each associated with increased risk of hemorrhagic stroke. Conclusions: CHIP is associated with an increased risk of stroke, particularly with hemorrhagic and small vessel ischemic stroke. Future studies clarifying the relationship between CHIP and subtypes of stroke are needed.
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49. |
- Bhattacharya, Romit, et al.
(author)
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Risk factors for clonal hematopoiesis of indeterminate potential in people with HIV : a report from the REPRIEVE trial
- 2024
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In: Blood Advances. - 2473-9529. ; 8:4, s. 959-967
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Journal article (peer-reviewed)abstract
- Clonal hematopoiesis of indeterminate potential (CHIP), the clonal expansion of myeloid cells with leukemogenic mutations, results in increased coronary artery disease (CAD) risk. CHIP is more prevalent among people with HIV (PWH), but the risk factors are unknown. CHIP was identified among PWH in REPRIEVE (Randomized Trial to Prevent Vascular Events in HIV) using whole-exome sequencing. Logistic regression was used to associate sociodemographic factors and HIV-specific factors with CHIP adjusting for age, sex, and smoking status. In the studied global cohort of 4486 PWH, mean age was 49.9 (standard deviation [SD], 6.4) years; 1650 (36.8%) were female; and 3418 (76.2%) were non-White. CHIP was identified in 223 of 4486 (4.97%) and in 38 of 373 (10.2%) among those aged ≥60 years. Age (odds ratio [OR], 1.07; 95% confidence interval [CI], 1.05-1.09; P < .0001) and smoking (OR, 1.37; 95% CI, 1.14-1.66; P < .001) associated with increased odds of CHIP. Globally, participants outside of North America had lower odds of CHIP including sub- Saharan Africa (OR, 0.57; 95% CI, 0.4-0.81; P = .0019), South Asia (OR, 0.45; 95% CI, 0.23-0.80; P = .01), and Latin America/Caribbean (OR, 0.56; 95% CI, 0.34-0.87; P = .014). Hispanic/Latino ethnicity (OR, 0.38; 95% CI, 0.23-0.54; P = .002) associated with significantly lower odds of CHIP. Among HIV-specific factors, CD4 nadir <50 cells/mm3 associated with a 1.9-fold (95% CI, 1.21-3.05; P = .006) increased odds of CHIP, with the effect being significantly stronger among individuals with short duration of antiretroviral therapy (ART; OR, 4.15; 95% CI, 1.51-11.1; P = .005) (Pinteraction= .0492). Among PWH at low-to-moderate CAD risk on stable ART, smoking, CD4 nadir, North American origin, and non-Hispanic ethnicity associated with increased odds of CHIP.
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50. |
- Blanton, Michael R., et al.
(author)
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Sloan Digital Sky Survey IV : Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
- 2017
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In: Astronomical Journal. - : IOP Publishing Ltd. - 0004-6256 .- 1538-3881. ; 154:1
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Journal article (peer-reviewed)abstract
- We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and. high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median z similar to 0.03). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between z similar to 0.6 and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs. and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the. Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July.
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