| 1. |
- Arndt, D. S., et al.
(författare)
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STATE OF THE CLIMATE IN 2017
- 2018
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Ingår i: Bulletin of The American Meteorological Society - (BAMS). - : American Meteorological Society. - 0003-0007 .- 1520-0477. ; 99:8, s. S1-S310
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Forskningsöversikt (refereegranskat)
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| 2. |
- Dar, Pe'er, et al.
(författare)
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Cell-free DNA screening for prenatal detection of 22q11.2 deletion syndrome.
- 2022
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Ingår i: American journal of obstetrics and gynecology. - : Elsevier BV. - 1097-6868 .- 0002-9378. ; 227:1
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Tidskriftsartikel (refereegranskat)abstract
- Prenatal screening has historically focused primarily on detection of fetal aneuploidies. Cell-free DNA (cfDNA) now enables noninvasive screening for subchromosomal copy number variants, including 22q11.2 deletion syndrome (22q11.2DS or DiGeorge syndrome), which is the most common microdeletion and a leading cause of congenital heart defects and neurodevelopmental delay. Although smaller studies have demonstrated the feasibility of screening for 22q11.2DS, large cohort studies with postnatal confirmatory testing to assess test performance have not been reported.To assess the performance of SNP-based cfDNA prenatal screening for detection of 22q11.2DS.Patients who had SNP-based cfDNA prenatal screening for 22q11.2DS were prospectively enrolled at 21 centers in 6 countries. Prenatal or newborn DNA samples were requested in all cases for genetic confirmation with chromosomal microarray. The primary outcome was sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of cfDNA for detection of all deletions, including the classical deletion and nested deletions that are ≥500kb, in the 22q11.2 low copy repeat A-D region. Secondary outcomes included the prevalence of 22q11.2DS and performance of an updated cfDNA algorithm that was evaluated blinded to pregnancy outcome.Of 20,887 women enrolled, genetic outcome was available in 18,289 (87.6%). Twelve 22q11.2DS cases were confirmed in the cohort, including five (41.7%) nested deletions, yielding a prevalence of 1:1524. In the total cohort, cfDNA reported 17,976 (98.3%) as low risk for 22q11.2DS and 38 (0.2%) as high-risk; 275 (1.5%) were non-reportable. Overall, 9 of 12 cases of 22q11.2 were detected, yielding a sensitivity of 75.0% (95% CI: 42.8, 94.5); specificity of 99.84% (95% CI: 99.77, 99.89); PPV of 23.7% (95% CI: 11.44, 40.24) and NPV of 99.98% (95% CI: 99.95, 100). None of the cases with a non-reportable result was diagnosed with 22q11.2DS. The updated algorithm detected 10/12 cases (83.3%; 95% CI: 51.6-97.9) with a lower false positive rate (0.05% vs. 0.16%, p<0.001) and a PPV of 52.6% (10/19; 95% CI 28.9-75.6).Noninvasive cfDNA prenatal screening for 22q11.2DS can detect most affected cases, including smaller nested deletions, with a low false positive rate.
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| 3. |
- Flood, Victoria A., et al.
(författare)
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Evaluating modelled tropospheric columns of CH4, CO, and O3 in the Arctic using ground-based Fourier transform infrared (FTIR) measurements
- 2024
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Ingår i: Atmospheric Chemistry and Physics. - 1680-7316 .- 1680-7324. ; 24:2, s. 1079-1118
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Tidskriftsartikel (refereegranskat)abstract
- This study evaluates tropospheric columns of methane, carbon monoxide, and ozone in the Arctic simulated by 11 models. The Arctic is warming at nearly 4 times the global average rate, and with changing emissions in and near the region, it is important to understand Arctic atmospheric composition and how it is changing. Both measurements and modelling of air pollution in the Arctic are difficult, making model validation with local measurements valuable. Evaluations are performed using data from five high-latitude ground-based Fourier transform infrared (FTIR) spectrometers in the Network for the Detection of Atmospheric Composition Change (NDACC). The models were selected as part of the 2021 Arctic Monitoring and Assessment Programme (AMAP) report on short-lived climate forcers. This work augments the model-measurement comparisons presented in that report by including a new data source: column-integrated FTIR measurements, whose spatial and temporal footprint is more representative of the free troposphere than in situ and satellite measurements. Mixing ratios of trace gases are modelled at 3-hourly intervals by CESM, CMAM, DEHM, EMEP MSC-W, GEM-MACH, GEOS-Chem, MATCH, MATCH-SALSA, MRI-ESM2, UKESM1, and WRF-Chem for the years 2008, 2009, 2014, and 2015. The comparisons focus on the troposphere (0-7km partial columns) at Eureka, Canada; Thule, Greenland; Ny Ålesund, Norway; Kiruna, Sweden; and Harestua, Norway. Overall, the models are biased low in the tropospheric column, on average by -9.7% for CH4, -21% for CO, and -18% for O3. Results for CH4 are relatively consistent across the 4 years, whereas CO has a maximum negative bias in the spring and minimum in the summer and O3 has a maximum difference centered around the summer. The average differences for the models are within the FTIR uncertainties for approximately 15% of the model-location comparisons.
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| 4. |
- Martin, Kimberly, et al.
(författare)
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Impact of high-risk prenatal screening results for 22q11.2 deletion syndrome on obstetric and neonatal management: Secondary analysis from the SMART study
- 2023
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Ingår i: Prenatal Diagnosis. - 0197-3851 .- 1097-0223. ; 43:13, s. 1574-1580
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Tidskriftsartikel (refereegranskat)abstract
- Objective: One goal of prenatal genetic screening is to optimize perinatal care and improve infant outcomes. We sought to determine whether high-risk cfDNA screening for 22q11.2 deletion syndrome (22q11.2DS) affected prenatal or neonatal management. Methods: This was a secondary analysis from the SMART study. Patients with high-risk cfDNA results for 22q11.2DS were compared with the low-risk cohort for pregnancy characteristics and obstetrical management. To assess differences in neonatal care, we compared high-risk neonates without prenatal genetic confirmation with a 1:1 matched low-risk cohort. Results: Of 18,020 eligible participants enrolled between 2015 and 2019, 38 (0.21%) were high-risk and 17,982 (99.79%) were low-risk for 22q11.2DS by cfDNA screening. High-risk participants had more prenatal diagnostic testing (55.3%; 21/38 vs. 2.0%; 352/17,982, p<0.001) and fetal echocardiography (76.9%; 10/13 vs. 19.6%; 10/51, p<0.001). High-risk newborns without prenatal diagnostic testing had higher rates of neonatal genetic testing (46.2%; 6/13 vs. 0%; 0/51, P<0.001), echocardiography (30.8%; 4/13 vs. 4.0%; 2/50, p=0.013), evaluation of calcium levels (46.2%; 6/13 vs. 4.1%; 2/49, P<0.001) and lymphocyte count (53.8%; 7/13 vs. 15.7%; 8/51, p=0.008). Conclusions: High-risk screening results for 22q11.2DS were associated with higher rates of prenatal and neonatal diagnostic genetic testing and other 22q11.2DS-specific evaluations. However, these interventions were not universally performed, and >50% of high-risk infants were discharged without genetic testing, representing possible missed opportunities to improve outcomes for affected individuals.
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| 5. |
- Martin, Kimberly, et al.
(författare)
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Performance of prenatal cfDNA screening for sex chromosomes.
- 2023
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Ingår i: Genetics in medicine : official journal of the American College of Medical Genetics. - 1530-0366. ; 25:8
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Tidskriftsartikel (refereegranskat)abstract
- To assess the performance of cell-free DNA (cfDNA) screening to detect sex chromosome aneuploidies (SCA) in an unselected obstetrical population with genetic confirmation.This was a planned secondary analysis of the multicenter, prospective SMART study. Patients receiving cfDNA results for autosomal aneuploidies and who had confirmatory genetic results for the relevant sex chromosomal aneuploidies were included. Screening performance for SCAs, including monosomy X (MX) and the sex chromosome trisomies (SCTs; 47,XXX; 47,XXY; 47,XYY) was determined. Fetal sex concordance between cfDNA and genetic screening was also evaluated in euploid pregnancies.17,538 cases met inclusion criteria. Performance of cfDNA for MX, SCTs and fetal sex was determined in 17,297, 10,333 and 14,486 pregnancies, respectively. Sensitivity, specificity, and PPV of cfDNA were 83.3%, 99.9%, and 22.7% for MX, and 70.4%, 99.9%, and 82.6% for the combined SCTs. The accuracy of fetal sex prediction by cfDNA was 100%.Screening performance of cfDNA for SCAs is comparable to that reported in other studies. The PPV for the SCTs was similar to the autosomal trisomies, while the PPV for MX was substantially lower. No discordance in fetal sex was observed between cfDNA and postnatal genetic screening in euploid pregnancies. These data will assist interpretation and counseling for cfDNA results for sex chromosomes.
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| 6. |
- Norton, Mary E, et al.
(författare)
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Obstetrical, perinatal and genetic outcomes associated with non-reportable prenatal cell free DNA screening results.
- 2023
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Ingår i: American journal of obstetrics and gynecology. - : Elsevier BV. - 0002-9378 .- 1097-6868. ; 229:3
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Tidskriftsartikel (refereegranskat)abstract
- The clinical implications of non-reportable cfDNA screening results are uncertain, but this may reflect poor placental implantation in some cases and be associated with adverse obstetrical and perinatal outcomes.To assess the outcomes of pregnancies with non-reportable cell-free DNA (cfDNA) screening in a cohort of patients with complete genetic and obstetric outcomes.This was a prespecified secondary analysis of a multicenter prospective observational study of prenatal cfDNA screening for fetal aneuploidy and 22q11.2 deletion syndrome. Participants who underwent cfDNA screening from April 2015 through January 2019 were offered participation. Obstetric outcomes and neonatal genetic testing results were collected from 21 primary care and referral centers in the US, Europe, and Australia. The primary outcome was risk for adverse obstetrical and perinatal outcomes (aneuploidy, preterm birth (PTB) at <28, <34, and <37 weeks' gestation, preeclampsia, small for gestational age (SGA) or birthweight <10th percentile for gestational week, and a composite outcome that included PTB<37 weeks, preeclampsia, SGA, and stillbirth>20 weeks') after non-reportable cfDNA screening due to low fetal fraction or other causes. Multivariable analyses were performed, adjusting for variables known to be associated with obstetrical and perinatal outcomes, non-reportable results, or fetal fraction.In total, 25,199 pregnant individuals were screened, and 20,194 were enrolled. Genetic confirmation was missing in 1165 (5.8%), 1085 (5.4%) were lost to follow-up, and 93 (0.5%) withdrew; the final study cohort included 17,851 (88.4%) participants who had cfDNA, fetal or newborn genetic confirmatory testing, and obstetrical and perinatal outcomes collected. Results were non-reportable in 602 (3.4%). A sample was redrawn and testing again attempted in 427; in 112 (26.2%) results were again non-reportable. Non-reportable results were associated with higher BMI, chronic hypertension, later gestational age, lower fetal fraction, and Black race. Trisomy 13, 18, or 21 was confirmed in 1.6% with non-reportable tests vs. 0.7% with results (p=.013). PTB <28, 34, and 37 weeks, preeclampsia, and the composite outcome were higher after non-reportable results, and further increased with a second non-reportable test, while SGA was not increased. After adjustment for confounders, the aOR for aneuploidy was 2.2 (95% CI 1.1, 4.4) and 2.6 (95% CI 0.6, 10.8) and for the composite outcome was 1.5 (95% CI 1.2, 1.8) and 2.1 (95% CI 1.4, 3.2) after a first and second non-reportable test. In all, 94.9% of patients with non-reportable tests had a livebirth as compared to 98.8% with those with test results obtained (aOR for livebirth: 0.20 [95% CI 0.13-0.30]).Patients with non-reportable cfDNA results are at increased risk for a number of adverse outcomes, including aneuploidy as well as preeclampsia and preterm birth. They should be offered diagnostic genetic testing and clinicians should be aware of the increased risk of pregnancy complications.
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| 7. |
- Norton, Mary E., et al.
(författare)
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Obstetrical, Perinatal, and Genetic Outcomes Associated With Nonreportable Prenatal Cell-Free DNA Screening Results
- 2024
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Ingår i: OBSTETRICAL & GYNECOLOGICAL SURVEY. - 0029-7828 .- 1533-9866. ; 79:3, s. 146-148
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Tidskriftsartikel (refereegranskat)abstract
- Although cell-free DNA (cfDNA) prenatal screening is widely used and has high sensitivity and specificity, there are circumstances in which the screening does not provide an interpretable result. Although this is relatively uncommon, it happens enough that clinical implications and potential reasons for follow-up should be studied and assessed. This study was designed to evaluate outcomes for pregnancies with nonreportable results on cfDNA screening tests. This study was a secondary analysis of the data from a multicenter prospective observational study of cfDNA screening for aneuploidy and 22q11.2 deletion syndrome. All patients were tested for trisomies 13, 18, and 21, as well as the 22q11.2 deletion syndrome, and all patients had confirmatory testing on the newborns in addition to collecting obstetric and perinatal outcomes. Inclusion criteria were women older than 18 years and at greater than 9 weeks of gestation with a singleton pregnancy. Exclusion criteria were having received cfDNA screening results before enrollment, organ transplant, ovum donation, vanishing twin, or being unwilling to provide a newborn sample. The primary outcome was the rate of adverse obstetrical and perinatal outcomes, including aneuploidy; preterm birth at less than 28, 34, or 37 weeks' gestation; preeclampsia; small for gestational age birth; and a composite outcome that included preterm birth before 37 weeks, preeclampsia, stillbirth at greater than 20 weeks, and small for gestational age. Final analyses included 17,851 individuals who had cfDNA screening, confirmatory genetic testing on the newborn, and obstetrical and perinatal outcomes recorded. Nonreportable results were found in 602 individuals (3.4%) after the first draw, with 32.2% of these due to low fetal fraction. Another third of the cohort had patterns where the risk of aneuploidy was uninterpretable but with an adequate fetal fraction, and in the final third, the fetal fraction could not be measured. Of the original 602 cases of nonreportable findings, 427 had a second draw, with 112 of these (26.2%) again having nonreportable results. There were no significant differences in baseline characteristics of age and parity for those with successful versus nonreportable test results; gestational age was significantly higher in individuals with nonreportable results (14.4 vs 13.4 weeks, P < 0.001), as was body mass index (26.2 vs 31.3), and the rate of chronic hypertension (4.0% vs 9.7%). In this cohort, there were 133 genetically confirmed trisomies, with 100 fetuses with trisomy 21, 18 individuals with trisomy 18, and 15 individuals with trisomy 13. Overall, the rate of aneuploidy was 1.7% in individuals with nonreportable results, versus 0.7% in those with reported results (P = 0.013; adjusted odds ratio [aOR] 2.1; 95% confidence interval [CI], 1.1-4.0). Rates of preterm birth were also higher in those with nonreportable test results, with delivery at less than 34 weeks at 1.5% in those with a test result, 4.6% in those with one nonreportable test result and 6.9% in those with a second nonreportable test result (aOR, 2.2 and 2.7; 95% CI, 1.4-3.4 and 1.2-6.0, respectively). Preeclampsia showed a similar trend, with rates climbing from 3.9% in those with a reported result to 9.4% with 1 nonreportable result and 16.8% with 2 (aOR, 1.4 and 2.0; 95% CI, 1.0-1.9 and 1.1-3.7, respectively). Chances of live birth were significantly reduced in pregnancies with a nonreportable results (aOR, 0.20; 95% CI, 0.13-0.30), with the chances decreasing more after a second nonreportable test result (aOR, 0. 11; 95% CI, 0.06-0.23). The study found that nonreportable cfDNA screening results are associated with an increased risk for aneuploidy, preterm birth, and preeclampsia, with a gradient of increased risk with a second failed test. This adds to literature with conflicting findings surrounding obstetrical complications in those with altered cfDNA levels and with most studies largely focused on characteristics that may be predictive of a nonreportable result rather than outcomes associated with nonreportable results. These results can inform clinicians who have patients with nonreportable test results in a way that may help them provide better care; future research should focus on more fully understanding the adverse outcomes associated with nonreportable tests to maximize this ability for clinicians in the future. Further research should also focus on specific populations or diagnoses to understand if there are fundamental differences in different groups of individuals.
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| 8. |
- Risi, Camille, et al.
(författare)
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Process-evaluation of tropospheric humidity simulated by general circulation models using water vapor isotopologues : 1. Comparison between models and observations
- 2012
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Ingår i: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 117, s. D05303-
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Tidskriftsartikel (refereegranskat)abstract
- The goal of this study is to determine how H2O and HDO measurements in water vapor can be used to detect and diagnose biases in the representation of processes controlling tropospheric humidity in atmospheric general circulation models (GCMs). We analyze a large number of isotopic data sets (four satellite, sixteen ground-based remote-sensing, five surface in situ and three aircraft data sets) that are sensitive to different altitudes throughout the free troposphere. Despite significant differences between data sets, we identify some observed HDO/H2O characteristics that are robust across data sets and that can be used to evaluate models. We evaluate the isotopic GCM LMDZ, accounting for the effects of spatiotemporal sampling and instrument sensitivity. We find that LMDZ reproduces the spatial patterns in the lower and mid troposphere remarkably well. However, it underestimates the amplitude of seasonal variations in isotopic composition at all levels in the subtropics and in midlatitudes, and this bias is consistent across all data sets. LMDZ also underestimates the observed meridional isotopic gradient and the contrast between dry and convective tropical regions compared to satellite data sets. Comparison with six other isotope-enabled GCMs from the SWING2 project shows that biases exhibited by LMDZ are common to all models. The SWING2 GCMs show a very large spread in isotopic behavior that is not obviously related to that of humidity, suggesting water vapor isotopic measurements could be used to expose model shortcomings. In a companion paper, the isotopic differences between models are interpreted in terms of biases in the representation of processes controlling humidity.
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| 9. |
- Sha, Mahesh Kumar, et al.
(författare)
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Validation of methane and carbon monoxide from Sentinel-5 Precursor using TCCON and NDACC-IRWG stations
- 2021
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Ingår i: Atmospheric Measurement Techniques. - : Copernicus GmbH. - 1867-1381 .- 1867-8548. ; 14:9, s. 6249-6304
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Tidskriftsartikel (refereegranskat)abstract
- The Sentinel-5 Precursor (S5P) mission with the TROPOspheric Monitoring Instrument (TROPOMI) on board has been measuring solar radiation backscattered by the Earth's atmosphere and surface since its launch on 13 October 2017. In this paper, we present for the first time the S5P operational methane (CH4) and carbon monoxide (CO) products' validation results covering a period of about 3 years using global Total Carbon Column Observing Network (TCCON) and Infrared Working Group of the Network for the Detection of Atmospheric Composition Change (NDACC-IRWG) network data, accounting for a priori alignment and smoothing uncertainties in the validation, and testing the sensitivity of validation results towards the application of advanced co-location criteria. We found that the S5P standard and bias-corrected CH4 data over land surface for the recommended quality filtering fulfil the mission requirements. The systematic difference of the bias-corrected total column-averaged dry air mole fraction of methane (XCH4) data with respect to TCCON data is -0.26 +/- 0.56 % in comparison to -0.68 +/- 0.74 % for the standard XCH4 data, with a correlation of 0.6 for most stations. The bias shows a seasonal dependence. We found that the S5P CO data over all surfaces for the recommended quality filtering generally fulfil the missions requirements, with a few exceptions, which are mostly due to co-location mismatches and limited availability of data. The systematic difference between the S5P total column-averaged dry air mole fraction of carbon monoxide (XCO) and the TCCON data is on average 9.22 +/- 3.45 % (standard TCCON XCO) and 2.45 +/- 3.38 % (unscaled TCCON XCO). We found that the systematic difference between the S5P CO column and NDACC CO column (excluding two outlier stations) is on average 6.5 +/- 3.54 %. We found a correlation of above 0.9 for most TCCON and NDACC stations. The study shows the high quality of S5P CH4 and CO data by validating the products against reference global TCCON and NDACC stations covering a wide range of latitudinal bands, atmospheric conditions and surface conditions.
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