27 research outputs found

    Mass balance of the Greenland Ice Sheet from 1992 to 2018

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    In recent decades, the Greenland Ice Sheet has been a major contributor to global sea-level rise1,2, and it is expected to be so in the future3. Although increases in glacier flow4–6 and surface melting7–9 have been driven by oceanic10–12 and atmospheric13,14 warming, the degree and trajectory of today’s imbalance remain uncertain. Here we compare and combine 26 individual satellite measurements of changes in the ice sheet’s volume, flow and gravitational potential to produce a reconciled estimate of its mass balance. Although the ice sheet was close to a state of balance in the 1990s, annual losses have risen since then, peaking at 335 ± 62 billion tonnes per year in 2011. In all, Greenland lost 3,800 ± 339 billion tonnes of ice between 1992 and 2018, causing the mean sea level to rise by 10.6 ± 0.9 millimetres. Using three regional climate models, we show that reduced surface mass balance has driven 1,971 ± 555 billion tonnes (52%) of the ice loss owing to increased meltwater runoff. The remaining 1,827 ± 538 billion tonnes (48%) of ice loss was due to increased glacier discharge, which rose from 41 ± 37 billion tonnes per year in the 1990s to 87 ± 25 billion tonnes per year since then. Between 2013 and 2017, the total rate of ice loss slowed to 217 ± 32 billion tonnes per year, on average, as atmospheric circulation favoured cooler conditions15 and as ocean temperatures fell at the terminus of Jakobshavn Isbræ16. Cumulative ice losses from Greenland as a whole have been close to the IPCC’s predicted rates for their high-end climate warming scenario17, which forecast an additional 50 to 120 millimetres of global sea-level rise by 2100 when compared to their central estimate

    Mass balance of the Greenland and Antarctic ice sheets from 1992 to 2020

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    Ice losses from the Greenland and Antarctic ice sheets have accelerated since the 1990s, accounting for a significant increase in the global mean sea level. Here, we present a new 29-year record of ice sheet mass balance from 1992 to 2020 from the Ice Sheet Mass Balance Inter-comparison Exercise (IMBIE). We compare and combine 50 independent estimates of ice sheet mass balance derived from satellite observations of temporal changes in ice sheet flow, in ice sheet volume, and in Earth's gravity field. Between 1992 and 2020, the ice sheets contributed 21.0±1.9g€¯mm to global mean sea level, with the rate of mass loss rising from 105g€¯Gtg€¯yr-1 between 1992 and 1996 to 372g€¯Gtg€¯yr-1 between 2016 and 2020. In Greenland, the rate of mass loss is 169±9g€¯Gtg€¯yr-1 between 1992 and 2020, but there are large inter-annual variations in mass balance, with mass loss ranging from 86g€¯Gtg€¯yr-1 in 2017 to 444g€¯Gtg€¯yr-1 in 2019 due to large variability in surface mass balance. In Antarctica, ice losses continue to be dominated by mass loss from West Antarctica (82±9g€¯Gtg€¯yr-1) and, to a lesser extent, from the Antarctic Peninsula (13±5g€¯Gtg€¯yr-1). East Antarctica remains close to a state of balance, with a small gain of 3±15g€¯Gtg€¯yr-1, but is the most uncertain component of Antarctica's mass balance. The dataset is publicly available at 10.5285/77B64C55-7166-4A06-9DEF-2E400398E452 (IMBIE Team, 2021)

    Cognitive impairment and dementia after intracerebral hemorrhage: a cross-sectional study of a hospital-based series.

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    Frequencies of cognitive impairment and dementia have not been assessed in spontaneous intracerebral hemorrhage (ICH). The objective of this study was to determine the frequencies and patterns of cognitive impairment and dementia in a cross-sectional study of consecutive patients hospitalized in a single university medical center.Journal Articleinfo:eu-repo/semantics/publishe

    Breastfeeding with maternal antiretroviral therapy or formula feeding to prevent HIV postnatal mother-to-child transmission in Rwanda.: Prevention of postnatal HIV transmission

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    International audienceOBJECTIVE: To assess the 9-month HIV-free survival of children with two strategies to prevent HIV mother-to-child transmission. DESIGN: Nonrandomized interventional cohort study. SETTING: Four public health centres in Rwanda. PARTICIPANTS: Between May 2005 and January 2007, all consenting HIV-infected pregnant women were included. INTERVENTION: Women could choose the mode of feeding for their infant: breastfeeding with maternal HAART for 6 months or formula feeding. All received HAART from 28 weeks of gestation. Nine-month cumulative probabilities of HIV transmission and HIV-free survival were determined using the Kaplan-Meier method and compared using the log-rank test. Determinants were analysed using a Cox model analysis. RESULTS: Of the 532 first-liveborn infants, 227 (43%) were breastfeeding and 305 (57%) were formula feeding. Overall, seven (1.3%) children were HIV-infected of whom six were infected in utero. Only one child in the breastfeeding group became infected between months 3 and 7, corresponding to a 9-month cumulative risk of postnatal infection of 0.5% [95% confidence interval (CI) 0.1-3.4%; P = 0.24] with breastfeeding. Nine-month cumulative mortality was 3.3% (95% CI 1.6-6.9%) in the breastfeeding arm group and 5.7% (95% CI 3.6-9.2%) for the formula feeding group (P = 0.20). HIV-free survival by 9 months was 95% (95% CI 91-97%) in the breastfeeding group and 94% (95% CI 91-96%) for the formula feeding group (P = 0.66), with no significant difference in the adjusted analysis (adjusted hazard ratio for breastfeeding: 1.2 (95% CI 0.5-2.9%). CONCLUSION:: Maternal HAART while breastfeeding could be a promising alternative strategy in resource-limited countries

    Detection, localisation and characterisation of prostate cancer by prostate HistoScanning™

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    OBJECTIVE: • To evaluate the ability of prostate HistoScanning™ (PHS) an ultrasound (US)-based tissue characterization application, to detect cancer foci by correlating results with detailed radical prostatectomy (RP) histology. PATIENT AND METHODS: • In all, 31 patients with organ-confined prostate cancer, diagnosed on transrectal biopsies taken using US guidance, and scheduled for RP were recruited from six European centres. • Before RP three-dimensional (3D) US raw data for PHS analysis was obtained. Histology by Bostwick Laboratories (London) examined sections obtained from whole mounted glands cut every 3-4 mm. • Location and volume estimation of cancer foci by PHS were undertaken using two methods; a manual method and an embedded software tool. • In this report we evaluate data obtained from a planned open study phase. The second phase of the study is'blinded ', and currently in progress. RESULTS: • 31 patients were eligible for this phase. Three patients were excluded from analysis due to inadequate scan acquisition and pathology violations of the standard operating procedure. One patient withdrew from the study after 3D TRUS examination. • PHS detected cancer ≥0.20 mL in 25/27 prostates (sensitivity 93%). • In all, 23 patients had an index focus ≥0.5 mL at pathology, of which 21 were identified as ≥0.5 mL by PHS using the manual method (sensitivity 91%) and 19 were correctly identified as ≥0.5 mL by the embedded tool (sensitivity 83%). • In 27 patients, histological analysis found 32 cancerous foci ge;0.2 mL, located in 97 of 162 sextants. After sextant analysis, PHS showed a 90% sensitivity and 72% specificity for the localisation of lesions ≥0.2 mL within a sextant. CONCLUSIONS: • PHS has the ability to identify and locate prostate cancer and consequently may aid in pre-treatment and pre-surgical planning. • In men with a lesion identified, it has potential to enable improved targeting, allowing better risk stratification by obtaining more representative cores. • However further verification from the results of the blinded phase of this study are awaited. © 2011 The Authors BJU International © 2011 BJU International.SCOPUS: ar.jFLWINinfo:eu-repo/semantics/publishe

    Delaying standard combined chemoradiotherapy after surgical resection does not impact survival in newly diagnosed glioblastoma patients

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    International audienceBACKGROUND:To assess the influence of the time interval between surgical resection and standard combined chemoradiotherapy on survival in newly diagnosed and homogeneously treated (surgical resection plus standard combined chemoradiotherapy) glioblastoma patients; while controlling confounding factors (extent of resection, carmustine wafer implantation, functional status, neurological deficit, and postoperative complications).METHODS:From 2005 to 2011, 692 adult patients (434 men; mean of 57.5 ± 10.8 years) with a newly diagnosed glioblastoma were enrolled in this retrospective multicentric study. All patients were treated by surgical resection (65.5% total/subtotal resection, 34.5% partial resection; 36.7% carmustine wafer implantation) followed by standard combined chemoradiotherapy (radiotherapy at a median dose of 60 Gy, with daily concomitant and adjuvant temozolomide). Time interval to standard combined chemoradiotherapy was analyzed as a continuous variable and as a dichotomized variable using median and quartiles thresholds. Multivariate analyses using Cox modeling were conducted.RESULTS:The median progression-free survival was 10.3 months (95% CI, 10.0-11.0). The median overall survival was 19.7 months (95% CI, 18.5-21.0). The median time to initiation of combined chemoradiotherapy was 1.5 months (25% quartile, 1.0; 75% quartile, 2.2; range, 0.1-9.0). On univariate and multivariate analyses, OS and PFS were not significantly influenced by time intervals to adjuvant treatments. On multivariate analysis, female gender, total/subtotal resection and RTOG-RPA classes 3 and 4 were significant independent predictors of improved OS.CONCLUSIONS:Delaying standard combined chemoradiotherapy following surgical resection of newly diagnosed glioblastoma in adult patients does not impact survival
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