| 1. |
- Abelev, Betty, et al.
(author)
-
Long-range angular correlations on the near and away side in p-Pb collisions at root S-NN=5.02 TeV
- 2013
-
In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 719:1-3, s. 29-41
-
Journal article (peer-reviewed)abstract
- Angular correlations between charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV for transverse momentum ranges within 0.5 < P-T,P-assoc < P-T,P-trig < 4 GeV/c. The correlations are measured over two units of pseudorapidity and full azimuthal angle in different intervals of event multiplicity, and expressed as associated yield per trigger particle. Two long-range ridge-like structures, one on the near side and one on the away side, are observed when the per-trigger yield obtained in low-multiplicity events is subtracted from the one in high-multiplicity events. The excess on the near-side is qualitatively similar to that recently reported by the CMS Collaboration, while the excess on the away-side is reported for the first time. The two-ridge structure projected onto azimuthal angle is quantified with the second and third Fourier coefficients as well as by near-side and away-side yields and widths. The yields on the near side and on the away side are equal within the uncertainties for all studied event multiplicity and p(T) bins, and the widths show no significant evolution with event multiplicity or p(T). These findings suggest that the near-side ridge is accompanied by an essentially identical away-side ridge. (c) 2013 CERN. Published by Elsevier B.V. All rights reserved.
|
|
| 2. |
- Abelev, Betty, et al.
(author)
-
Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV
- 2012
-
In: Journal of High Energy Physics. - 1029-8479. ; :11
-
Journal article (peer-reviewed)abstract
- The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.
|
|
| 3. |
- Abelev, Betty, et al.
(author)
-
Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC
- 2012
-
In: Journal of High Energy Physics. - 1029-8479. ; :7
-
Journal article (peer-reviewed)abstract
- We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.
|
|
| 4. |
- Kattge, Jens, et al.
(author)
-
TRY plant trait database - enhanced coverage and open access
- 2020
-
In: Global Change Biology. - : Wiley-Blackwell. - 1354-1013 .- 1365-2486. ; 26:1, s. 119-188
-
Journal article (peer-reviewed)abstract
- Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives.
|
|
| 5. |
- Biurrun, Idoia, et al.
(author)
-
Benchmarking plant diversity of Palaearctic grasslands and other open habitats
- 2021
-
In: Journal of Vegetation Science. - Oxford : John Wiley & Sons. - 1100-9233 .- 1654-1103. ; 32:4
-
Journal article (peer-reviewed)abstract
- Journal of Vegetation Science published by John Wiley & Sons Ltd on behalf of International Association for Vegetation Science.Aims: Understanding fine-grain diversity patterns across large spatial extents is fundamental for macroecological research and biodiversity conservation. Using the GrassPlot database, we provide benchmarks of fine-grain richness values of Palaearctic open habitats for vascular plants, bryophytes, lichens and complete vegetation (i.e., the sum of the former three groups). Location: Palaearctic biogeographic realm. Methods: We used 126,524 plots of eight standard grain sizes from the GrassPlot database: 0.0001, 0.001, 0.01, 0.1, 1, 10, 100 and 1,000 m2 and calculated the mean richness and standard deviations, as well as maximum, minimum, median, and first and third quartiles for each combination of grain size, taxonomic group, biome, region, vegetation type and phytosociological class. Results: Patterns of plant diversity in vegetation types and biomes differ across grain sizes and taxonomic groups. Overall, secondary (mostly semi-natural) grasslands and natural grasslands are the richest vegetation type. The open-access file ”GrassPlot Diversity Benchmarks” and the web tool “GrassPlot Diversity Explorer” are now available online (https://edgg.org/databases/GrasslandDiversityExplorer) and provide more insights into species richness patterns in the Palaearctic open habitats. Conclusions: The GrassPlot Diversity Benchmarks provide high-quality data on species richness in open habitat types across the Palaearctic. These benchmark data can be used in vegetation ecology, macroecology, biodiversity conservation and data quality checking. While the amount of data in the underlying GrassPlot database and their spatial coverage are smaller than in other extensive vegetation-plot databases, species recordings in GrassPlot are on average more complete, making it a valuable complementary data source in macroecology. © 2021 The Authors.
|
|
| 6. |
- Molnár, Christian, et al.
(author)
-
Islet Engraftment and Revascularization in Clinical and Experimental Transplantation
- 2013
-
In: Cell Transplantation. - 0963-6897 .- 1555-3892. ; 22:2, s. 243-251
-
Journal article (peer-reviewed)abstract
- Background:Proper revascularization after transplantation is assumed to be crucial forappropriate islet graft function.Methods:We developed a novel non-invasive imagingmethod, based on adenoviral transduction of islets with a hypoxia responsive reporter gene,for continuous in vivo monitoring of hypoxia in islet grafts in a mouse model. In addition,morphological data was obtained from a deceased patient previously subject to intraportaltransplantation.Results:We detected only transient hypoxia in a minority of the animalstransplanted. Importantly, a clear response to hypoxia was observed in vitro after removal ofthe islet-grafts on day twenty-eight after transplantation. Also, the morphological data fromthe deceased patient demonstrated an extensive revascularization of the transplanted islets. Infact, no differences could be seen between native, in pancreas biopsies taken prior to isletisolation, and transplanted islets regarding the number, distribution and shape of the bloodvessels. However, fewer small islets (diameter <39μm) were found in the liver compared to those found in native pancreases. Notably, an absolute majority of the transplanted islets were found remaining within the venous lumen, in direct contact with the vessel wall.Conclusions:In conclusion results presented show less pronounced islet graft hypoxia after subcapsulartransplantation than previously reported using more invasive methods. Also, formation of anextensive intra-islet capillary network, similar to that seen in native islets in the pancreas, wasseen after clinical islet transplantation.
|
|
| 7. |
- Almazan, Nerea Martin, et al.
(author)
-
Influenza-A mediated pre-existing immunity levels to SARS-CoV-2 could predict early COVID-19 outbreak dynamics
- 2023
-
In: iScience. - : CELL PRESS. - 2589-0042. ; 26:12
-
Journal article (peer-reviewed)abstract
- Susceptibility to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections is highly variable and could be mediated by a cross-protective pre-immunity. We identified 14 cross-reactive peptides between SARS-CoV-2 and influenza A H1N1, H3N2, and human herpesvirus (HHV)-6A/B with potential relevance. The H1N1 peptide NGVEGF was identical to a peptide in the most critical receptor binding motif in SARS-CoV-2 spike protein that interacts with the angiotensin converting enzyme 2 receptor. About 62%-73% of COVID-19-negative blood donors in Stockholm had antibodies to this peptide in the early pre-vaccination phase of the pandemic. Seasonal flu vaccination enhanced neutralizing capacity to SARS-CoV-2 and T cell immunity to this peptide. Mathematical modeling taking the estimated pre -immunity levels to flu into account could fully predict pre-Omicron SARS-CoV-2 outbreaks in Stockholm and India. This cross-immunity provides mechanistic explanations to the epidemiological observation that influenza vaccination protected people against early SARS-CoV-2 infections and implies that flu-mediated cross-protective immunity significantly dampened the first SARS-CoV-2 outbreaks.
|
|
| 8. |
|
|
| 9. |
- Dengler, Juergen, et al.
(author)
-
GrassPlot - a database of multi-scale plant diversity in Palaearctic grasslands
- 2018
-
In: Phytocoenologia. - : Schweizerbart. - 0340-269X. ; 48:3, s. 331-347
-
Journal article (peer-reviewed)abstract
- GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). GrassPlot collects plot records (releves) from grasslands and other open habitats of the Palaearctic biogeographic realm. It focuses on precisely delimited plots of eight standard grain sizes (0.0001; 0.001;... 1,000 m(2)) and on nested-plot series with at least four different grain sizes. The usage of GrassPlot is regulated through Bylaws that intend to balance the interests of data contributors and data users. The current version (v. 1.00) contains data for approximately 170,000 plots of different sizes and 2,800 nested-plot series. The key components are richness data and metadata. However, most included datasets also encompass compositional data. About 14,000 plots have near-complete records of terricolous bryophytes and lichens in addition to vascular plants. At present, GrassPlot contains data from 36 countries throughout the Palaearctic, spread across elevational gradients and major grassland types. GrassPlot with its multi-scale and multi-taxon focus complements the larger international vegetationplot databases, such as the European Vegetation Archive (EVA) and the global database " sPlot". Its main aim is to facilitate studies on the scale-and taxon-dependency of biodiversity patterns and drivers along macroecological gradients. GrassPlot is a dynamic database and will expand through new data collection coordinated by the elected Governing Board. We invite researchers with suitable data to join GrassPlot. Researchers with project ideas addressable with GrassPlot data are welcome to submit proposals to the Governing Board.
|
|
| 10. |
- Kilbo Edlund, Karl, et al.
(author)
-
High-resolution dispersion modelling of PM2.5, PM10, NOx and NO2 exposure in metropolitan areas in Sweden 2000‒2018 – large health gains due to decreased population exposure
- 2024
-
In: Air Quality, Atmosphere and Health. - 1873-9318 .- 1873-9326.
-
Journal article (peer-reviewed)abstract
- Ambient air pollution remains the major environmental cause of disease. Accurate assessment of population exposure and small-scale spatial exposure variations over long time periods is essential for epidemiological studies. We estimated annual exposure to fine and coarse particulate matter (PM2.5, PM10), and nitrogen oxides (NOx, NO2) with high spatial resolution to examine time trends 2000‒2018, compliance with the WHO Air Quality Guidelines, and assess the health impact. The modelling area covered six metropolitan areas in Sweden with a combined population of 5.5 million. Long-range transported air pollutants were modelled using a chemical transport model with bias correction, and locally emitted air pollutants using source-specific Gaussian-type dispersion models at resolutions up to 50 × 50m. The modelled concentrations were validated using quality-controlled monitoring data. Lastly, we estimated the reduction in mortality associated with the decrease in population exposure. The validity of modelled air pollutant concentrations was good (R2 for PM2.5 0.84, PM10 0.61, and NOx 0.87). Air pollution exposure decreased substantially, from a population weighted mean exposure to PM2.5 of 12.2µgm−3 in 2000 to 5.4µgm−3 in 2018. We estimated that the decreased exposure was associated with a reduction of 2719 (95% CI 2046–3055) premature deaths annually. However, in 2018, 65%, 8%, and 42% of residents in the modelled areas were still exposed to PM2.5, PM10, or NO2 levels, respectively, that exceeded the current WHO Air Quality Guidelines for annual average exposure. This emphasises the potential public health benefits of reductions in air pollution emissions.
|
|
| 11. |
- Kilbo Edlund, Karl, et al.
(author)
-
Long-term ambient air pollution and coronary atherosclerosis : results from the Swedish SCAPIS study
- 2024
-
In: Atherosclerosis. - : Elsevier. - 0021-9150 .- 1879-1484.
-
Journal article (peer-reviewed)abstract
- Background and aims: Despite firm evidence for an association between long-term ambient air pollution exposure and cardiovascular morbidity and mortality, results from epidemiological studies on the association between air pollution exposure and atherosclerosis have not been consistent. We investigated associations between long-term low-level air pollution exposure and coronary atherosclerosis.Methods: We performed a cross-sectional analysis in the large Swedish CArdioPulmonary bioImaging Study (SCAPIS, n = 30 154), a random general population sample. Concentrations of total and locally emitted particulate matter <2.5 μm (PM2.5), <10 μm (PM10), and nitrogen oxides (NOx) at the residential address were modelled using high-resolution dispersion models. We estimated associations between air pollution exposures and segment involvement score (SIS), coronary artery calcification score (CACS), number of non-calcified plaques (NCP), and number of significant stenoses, using ordinal regression models extensively adjusted for potential confounders.Results: Median 10-year average PM2.5 exposure was 6.2 μg/m3 (range 3.5–13.4 μg/m3). 51 % of participants were women and 51 % were never-smokers. None of the assessed pollutants were associated with a higher SIS or CACS. Exposure to PM2.5 was associated with NCP (adjusted OR 1.34, 95 % CI 1.13, 1.58, per 2.05 μg/m3). Associations with significant stenoses were inconsistent.Conclusions: In this large, middle-aged general population sample with low exposure levels, air pollution was not associated with measures of total burden of coronary atherosclerosis. However, PM2.5 appeared to be associated with a higher prevalence of non-calcified plaques. The results suggest that increased risk of early-stage atherosclerosis or rupture, but not increased total atherosclerotic burden, may be a pathway for long-term air pollution effects on cardiovascular disease.
|
|
| 12. |
- Kilbo Edlund, Karl, et al.
(author)
-
Long-term ambient air pollution and coronary atherosclerosis: Results from the Swedish SCAPIS study.
- 2024
-
In: Atherosclerosis. - 1879-1484.
-
Journal article (peer-reviewed)abstract
- Despite firm evidence for an association between long-term ambient air pollution exposure and cardiovascular morbidity and mortality, results from epidemiological studies on the association between air pollution exposure and atherosclerosis have not been consistent. We investigated associations between long-term low-level air pollution exposure and coronary atherosclerosis.We performed a cross-sectional analysis in the large Swedish CArdioPulmonary bioImaging Study (SCAPIS, n=30154), a random general population sample. Concentrations of total and locally emitted particulate matter <2.5μm (PM2.5), <10μm (PM10), and nitrogen oxides (NOx) at the residential address were modelled using high-resolution dispersion models. We estimated associations between air pollution exposures and segment involvement score (SIS), coronary artery calcification score (CACS), number of non-calcified plaques (NCP), and number of significant stenoses, using ordinal regression models extensively adjusted for potential confounders.Median 10-year average PM2.5 exposure was 6.2μg/m3 (range 3.5-13.4μg/m3). 51% of participants were women and 51% were never-smokers. None of the assessed pollutants were associated with a higher SIS or CACS. Exposure to PM2.5 was associated with NCP (adjusted OR 1.34, 95% CI 1.13, 1.58, per 2.05μg/m3). Associations with significant stenoses were inconsistent.In this large, middle-aged general population sample with low exposure levels, air pollution was not associated with measures of total burden of coronary atherosclerosis. However, PM2.5 appeared to be associated with a higher prevalence of non-calcified plaques. The results suggest that increased risk of early-stage atherosclerosis or rupture, but not increased total atherosclerotic burden, may be a pathway for long-term air pollution effects on cardiovascular disease.
|
|
| 13. |
|
|
| 14. |
- Lindahl, Johanna, et al.
(author)
-
High seroprevalence of SARS-CoV-2 in elderly care employees in Sweden
- 2020
-
In: Infection Ecology & Epidemiology. - : Informa UK Limited. - 2000-8686. ; 10:1
-
Journal article (peer-reviewed)abstract
- The COVID-19 pandemic is growing and spread in the Swedish elderly care system during April 2020. The increasing number of employees on sick-leave due to COVID-19 created severe logistic problems. Some elderly care homes therefore started to screen their personnel to secure the safety of the elderly and to avoid unnecessary quarantine of potentially immune employees.Secondary data from a screening with a COVID-19 rapid test for detection of SARS-CoV-2-specific IgM and IgG of 1,005 employees in 22 elderly care homes in Stockholm, Sweden, were analyzed. Seropositive employees were found in 21 out of the 22 care homes. In total, 23% (231/1,005) of the employees tested positive for antibodies against SARS-CoV-2, and 14.3% (144/1,005) were found positive for IgM (either alone or combined with IgG), indicating recent or present infection. Of those that tested seropositive, 46.5% did not report any clinical symptoms, indicating pre- or asymptomatic infections. Reported symptoms with the highest correlation with seropositivity were fever and loss of smell and taste.These results suggest that antibody testing of employees in elderly care homes is valuable for surveillance of disease development and a crucial screening tool in the effort to decrease the death toll in this pandemic.
|
|
| 15. |
- Malmström, Helena, et al.
(author)
-
Ancient DNA Reveals Lack of Continuitybetween Neolithic Hunter-Gatherersand Contemporary Scandinavians
- 2009
-
In: Current Biology. - : Elsevier. - 0960-9822 .- 1879-0445. ; 19:20, s. 1758-1762
-
Journal article (peer-reviewed)abstract
- The driving force behind the transition from a foraging to a farming lifestyle in prehistoric Europe (Neolithization) has been debated for more than a century [1–3]. Of particular interest is whether population replacement or cultural exchange was responsible [3–5]. Scandinavia holds a unique place in this debate, for it maintained one of the last major hunter-gatherer complexes in Neolithic Europe, the Pitted Ware culture [6]. Intriguingly, these late hunter-gatherers existed in parallel to early farmers for more than a millennium before they vanished some 4,000 years ago [7, 8]. The prolonged coexistence of the two cultures in Scandinavia has been cited as an argument against population replacement between the Mesolithic and the present [7, 8]. Through analysis of DNA extracted from ancient Scandinavian human remains, we show that people of the Pitted Ware culture were not the direct ancestors of modern Scandinavians (including the Saami people of northern Scandinavia) but are more closely related to contemporary populations of the eastern Baltic region. Our findings support hypotheses arising from archaeological analyses that propose a Neolithic or post-Neolithic population replacement in Scandinavia [7]. Furthermore, our data are consistent with the view that the eastern Baltic represents a genetic refugia for some of the European hunter-gatherer populations.
|
|
| 16. |
|
|
| 17. |
- Molnar, Miklos, et al.
(author)
-
Ytförstärkt murverk : Dimensionering och konstruktiv utformning
- 2024
-
Reports (pop. science, debate, etc.)abstract
- Handboken är inriktad på dimensionering och konstruktiv utformning av ytarmerat lättklinkermurverk. När det gäller andra murverksmaterial, sker dimensionering på samma sätt som för lättklinkermurverk. När det gäller konstruktiv utformning av främst byggnadsdetaljer, kan särskilda aspekter behöva beaktas, beroende på murverksmaterial.Handboken har tagits fram inom ramen för utvecklingsprojektet ”Demonstration av energi- och resurseffektiva murade ytterväggar”. Projektet genomfördes under perioden 2021 – 2023, med finansiering från Energimyndighetens forskningsprogram E2B2, anslag 37582-4. Projektet samfinansieras av Weber Saint-Gobain Sverige AB och Tomas Gustavsson konstruktioner AB.
|
|
| 18. |
- Purins, Karlis, et al.
(author)
-
Standardized experimental brain death model for studies of intracranial dynamics, organ preservation, and organ transplantation in the pig
- 2011
-
In: Critical Care Medicine. - 0090-3493 .- 1530-0293. ; 39:3, s. 512-517
-
Journal article (peer-reviewed)abstract
- OBJECTIVES:: Brain death impairs organ function and outcome after transplantation. There is a need for a brain death model to allow studies of organ viability and preservation. For neurointensive care research, it is also of interest to have a relevant brain death model for studies of intracranial dynamics and evaluation of cerebral monitoring devices. Therefore, the objective was to develop a standardized clinically relevant brain death model. METHODS:: Six pigs of both sexes (10-12 wks old; mean weight, 24.5 ± 1.4 kg) were included. Mean arterial blood pressure, heart rate, intracranial pressure, intracranial compliance, cerebral perfusion pressure, and brain tissue oxygenation (BtiPo2) were recorded during stepwise elevation of intracranial pressure by inflation of an epidural balloon catheter with saline (1 mL/20 mins). Brain death criteria were decided to be reached when cerebral perfusion pressure was <0 mm Hg for 60 mins and at least 10 mL saline was inflated epidurally. BtiPo2 and arterial injections of microspheres were used for confirmation of brain death. RESULTS:: A gradual volume-dependent elevation of intracranial pressure was observed. After 10 mL of balloon infusion, mean intracranial pressure was 89.8 ± 9.7 (sd) mm Hg. Intracranial compliance decreased from 0.137 ± 0.069 mL/mm Hg to 0.007 ± 0.001 mL/mm Hg. The mean arterial pressure decreased and the heart rate increased when the intracranial volume was increased to between 5 and 6 mL. All animals showed cerebral perfusion pressure ≤0 after 7 to 10 mL of infusion. In all animals, the criteria for brain death with negative cerebral perfusion pressure and BtiPo2 ∼0 mm Hg were achieved. Only a negligible amount of microspheres were found in the cerebrum, confirming brain death. The kidneys showed small foci of acute tubular necrosis. CONCLUSIONS:: The standardized brain death model designed in pigs simulates the clinical development of brain death in humans with a classic pressure-volume response and systemic cardiovascular reactions. Brain death was convincingly confirmed.
|
|
| 19. |
- van Leeuwen, F., et al.
(author)
-
Gaia Data Release 1 : Open cluster astrometry: Performance, limitations, and future prospects
- 2017
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 601
-
Journal article (peer-reviewed)abstract
- Context. The first Gaia Data Release contains the Tycho-Gaia Astrometric Solution (TGAS). This is a subset of about 2 million stars for which, besides the position and photometry, the proper motion and parallax are calculated using Hipparcos and Tycho-2 positions in 1991.25 as prior information. Aims. We investigate the scientific potential and limitations of the TGAS component by means of the astrometric data for open clusters. Methods. Mean cluster parallax and proper motion values are derived taking into account the error correlations within the astrometric solutions for individual stars, an estimate of the internal velocity dispersion in the cluster, and, where relevant, the effects of the depth of the cluster along the line of sight. Internal consistency of the TGAS data is assessed. Results. Values given for standard uncertainties are still inaccurate and may lead to unrealistic unit-weight standard deviations of least squares solutions for cluster parameters. Reconstructed mean cluster parallax and proper motion values are generally in very good agreement with earlier Hipparcos-based determination, although the Gaia mean parallax for the Pleiades is a significant exception. We have no current explanation for that discrepancy. Most clusters are observed to extend to nearly 15 pc from the cluster centre, and it will be up to future Gaia releases to establish whether those potential cluster-member stars are still dynamically bound to the clusters. Conclusions. The Gaia DR1 provides the means to examine open clusters far beyond their more easily visible cores, and can provide membership assessments based on proper motions and parallaxes. A combined HR diagram shows the same features as observed before using the Hipparcos data, with clearly increased luminosities for older A and F dwarfs.
|
|
| 20. |
- Vikström, Linnea, et al.
(author)
-
Vaccine-induced correlate of protection against fatal COVID-19 in older and frail adults during waves of neutralization-resistant variants of concern : an observational study
- 2023
-
In: The Lancet Regional Health. - : Elsevier. - 2666-7762. ; 30
-
Journal article (peer-reviewed)abstract
- BACKGROUND: To inform future preventive measures including repeated vaccinations, we have searched for a clinically useful immune correlate of protection against fatal COVID-19 among nursing homes residents.METHODS: We performed repeated capillary blood sampling with analysis of S-binding IgG in an open cohort of nursing home residents in Sweden. We analyzed immunological and registry data from 16 September 2021 to 31 August 2022 with follow-up of deaths to 30 September 2022. The study period included implementation of the 3rd and 4th mRNA monovalent vaccine doses and Omicron virus waves.FINDINGS: A total of 3012 nursing home residents with median age 86 were enrolled. The 3rd mRNA dose elicited a 99-fold relative increase of S-binding IgG in blood and corresponding increase of neutralizing antibodies. The 4th mRNA vaccine dose boosted levels 3.8-fold. Half-life of S-binding IgG was 72 days. A total 528 residents acquired their first SARS-CoV-2 infection after the 3rd or the 4th vaccine dose and the associated 30-day mortality was 9.1%. We found no indication that levels of vaccine-induced antibodies protected against infection with Omicron VOCs. In contrast, the risk of death was inversely correlated to levels of S-directed IgG below the 20th percentile. The death risk plateaued at population average above the lower 35th percentile of S-binding IgG.INTERPRETATION: In the absence of neutralizing antibodies that protect from infection, quantification of S-binding IgG post vaccination may be useful to identify the most vulnerable for fatal COVID-19 among the oldest and frailest. This information is of importance for future strategies to protect vulnerable populations against neutralization resistant variants of concern.FUNDING: Swedish Research Council, SciLifeLab via Knut and Alice Wallenberg Foundation, VINNOVA. Swedish Healthcare Regions, and Erling Persson Foundation.
|
|
