53 research outputs found
The dynamics of immune responses to <i>Mycobacterium tuberculosis </i>during different stages of natural infection:A longitudinal study among Greenlanders
OBJECTIVE:Understanding human immunity to Mycobacterium tuberculosis (Mtb) during different stages of infection is important for development of an effective tuberculosis (TB) vaccine. We aimed to evaluate immunity to Mtb infection by measuring immune responses to selected Mtb antigens expressed during different stages of infection over time and to observe sustainability of immunity. METHODS:In a cohort study comprising East Greenlanders aged 17-22 years (2012 to 2014) who had either; undetectable Mtb infection, ongoing or prior Mtb infection at enrolment, we measured immunity to 15 antigens over a one-year period. Quantiferon-TB Gold testing (QFT) defined Mtb infection status (undetected/detected). The eligible study population of East Greenlanders aged 17-22 years was identified from the entire population using the Civil Registration System. From the source population 65 participants were selected by stratified random sampling according to information on Mtb infection stage. Retrospective and prospective information on notified TB (including treatment) was obtained through the mandatory TB notification system and was used to characterise Mtb infection stage (ongoing/prior). Immunity to 15 antigens including two QFT antigens, PPD and 12 non-QFT antigens (representing early, constitutive and latent Mtb infection) was assessed by measuring immune responses using whole-blood antigen stimulation and interferon gamma measurement. RESULTS:Of 65 participants, 54 were considered Mtb-infected. Immunity to Mtb infection fluctuated with high annual risk of conversion (range: 6-69%) and reversion (range: 5-95%). During follow-up, five (8%) participants were notified with TB; neither conversion nor reversion was associated with an increased risk of progressing to TB. CONCLUSIONS:Our findings suggest that human immunity to natural Mtb infection over time is versatile with fluctuations, resulting in high levels of conversion and reversion of immunity, thus human immunity to Mtb is much more dynamic than anticipated. The study findings suggest future use of longitudinal assessment of immune responses when searching for TB vaccine candidate antigens
A Transiting Hot Jupiter Orbiting a Metal-Rich Star
We announce the discovery of Kepler-6b, a transiting hot Jupiter orbiting a
star with unusually high metallicity, [Fe/H] = +0.34 +/- 0.04. The planet's
mass is about 2/3 that of Jupiter, Mp = 0.67 Mj, and the radius is thirty
percent larger than that of Jupiter, Rp = 1.32 Rj, resulting in a density of
0.35 g/cc, a fairly typical value for such a planet. The orbital period is P =
3.235 days. The host star is both more massive than the Sun, Mstar = 1.21 Msun,
and larger than the Sun, Rstar = 1.39 Rsun.Comment: 12 pages, 2 figures, submitted to the Astrophysical Journal Letter
Allogeneic blood transfusion and prognosis following total hip replacement: a population-based follow up study
<p>Abstract</p> <p>Background</p> <p>Allogeneic red blood cell transfusion is frequently used in total hip replacement surgery (THR). However, data on the prognosis of transfused patients are sparse. In this study we compared the risk of complications following THR in transfused and non-transfused patients.</p> <p>Methods</p> <p>A population-based follow-up study was performed using data from medical databases in Denmark. We identified 28,087 primary THR procedures performed from 1999 to 2007, from which we computed a propensity score for red blood cell transfusion based on detailed data on patient-, procedure-, and hospital-related characteristics. We were able to match 2,254 transfused with 2,254 non-transfused THR patients using the propensity score.</p> <p>Results</p> <p>Of the 28,087 THR patients, 9,063 (32.3%) received at least one red blood cell transfusion within 8 days of surgery. Transfused patients had higher 90-day mortality compared with matched non-transfused patients: the adjusted OR was 2.2 (95% confidence interval (CI): 1.2-3.8). Blood transfusion was also associated with increased odds of pneumonia (OR 2.1; CI: 1.2-3.8), whereas the associations with cardiovascular or cerebrovascular events (OR 1.4; CI: 0.9-2.2) and venous thromboembolism (OR 1.2; CI: 0.7-2.1) did not reach statistical significance. The adjusted OR of reoperation due to infection was 0.6 (CI: 0.1-2.9).</p> <p>Conclusions</p> <p>Red blood cell transfusion was associated with an adverse prognosis following primary THR, in particular with increased odds of death and pneumonia. Although the odds estimates may partly reflect unmeasured bias due to blood loss, they indicate the need for careful assessment of the risk versus benefit of transfusion even in relation to routine THR procedures.</p
Detection of solar-like oscillations from Kepler photometry of the open cluster NGC 6819
Asteroseismology of stars in clusters has been a long-sought goal because the
assumption of a common age, distance and initial chemical composition allows
strong tests of the theory of stellar evolution. We report results from the
first 34 days of science data from the Kepler Mission for the open cluster NGC
6819 -- one of four clusters in the field of view. We obtain the first clear
detections of solar-like oscillations in the cluster red giants and are able to
measure the large frequency separation and the frequency of maximum oscillation
power. We find that the asteroseismic parameters allow us to test
cluster-membership of the stars, and even with the limited seismic data in
hand, we can already identify four possible non-members despite their having a
better than 80% membership probability from radial velocity measurements. We
are also able to determine the oscillation amplitudes for stars that span about
two orders of magnitude in luminosity and find good agreement with the
prediction that oscillation amplitudes scale as the luminosity to the power of
0.7. These early results demonstrate the unique potential of asteroseismology
of the stellar clusters observed by Kepler.Comment: 5 pages, 4 figures, accepted by ApJ (Lett.
Discovery and Rossiter-McLaughlin Effect of Exoplanet Kepler-8b
We report the discovery and the Rossiter-McLaughlin effect of Kepler-8b, a
transiting planet identified by the NASA Kepler Mission. Kepler photometry and
Keck-HIRES radial velocities yield the radius and mass of the planet around
this F8IV subgiant host star. The planet has a radius RP = 1.419 RJ and a mass,
MP = 0.60 MJ, yielding a density of 0.26 g cm^-3, among the lowest density
planets known. The orbital period is P = 3.523 days and orbital semima jor axis
is 0.0483+0.0006/-0.0012 AU. The star has a large rotational v sin i of 10.5
+/- 0.7 km s^-1 and is relatively faint (V = 13.89 mag), both properties
deleterious to precise Doppler measurements. The velocities are indeed noisy,
with scatter of 30 m s^-1, but exhibit a period and phase consistent with the
planet implied by the photometry. We securely detect the Rossiter-McLaughlin
effect, confirming the planet's existence and establishing its orbit as
prograde. We measure an inclination between the projected planetary orbital
axis and the projected stellar rotation axis of lambda = -26.9 +/- 4.6 deg,
indicating a moderate inclination of the planetary orbit. Rossiter-McLaughlin
measurements of a large sample of transiting planets from Kepler will provide a
statistically robust measure of the true distribution of spin-orbit
orientations for hot jupiters in general.Comment: 26 pages, 8 figures, 2 tables; In preparation for submission to the
Astrophysical Journa
Large-scale validation of methods for cytotoxic T-lymphocyte epitope prediction
<p>Abstract</p> <p>Background</p> <p>Reliable predictions of Cytotoxic T lymphocyte (CTL) epitopes are essential for rational vaccine design. Most importantly, they can minimize the experimental effort needed to identify epitopes. NetCTL is a web-based tool designed for predicting human CTL epitopes in any given protein. It does so by integrating predictions of proteasomal cleavage, TAP transport efficiency, and MHC class I affinity. At least four other methods have been developed recently that likewise attempt to predict CTL epitopes: EpiJen, MAPPP, MHC-pathway, and WAPP. In order to compare the performance of prediction methods, objective benchmarks and standardized performance measures are needed. Here, we develop such large-scale benchmark and corresponding performance measures and report the performance of an updated version 1.2 of NetCTL in comparison with the four other methods.</p> <p>Results</p> <p>We define a number of performance measures that can handle the different types of output data from the five methods. We use two evaluation datasets consisting of known HIV CTL epitopes and their source proteins. The source proteins are split into all possible 9 mers and except for annotated epitopes; all other 9 mers are considered non-epitopes. In the RANK measure, we compare two methods at a time and count how often each of the methods rank the epitope highest. In another measure, we find the specificity of the methods at three predefined sensitivity values. Lastly, for each method, we calculate the percentage of known epitopes that rank within the 5% peptides with the highest predicted score.</p> <p>Conclusion</p> <p>NetCTL-1.2 is demonstrated to have a higher predictive performance than EpiJen, MAPPP, MHC-pathway, and WAPP on all performance measures. The higher performance of NetCTL-1.2 as compared to EpiJen and MHC-pathway is, however, not statistically significant on all measures. In the large-scale benchmark calculation consisting of 216 known HIV epitopes covering all 12 recognized HLA supertypes, the NetCTL-1.2 method was shown to have a sensitivity among the 5% top-scoring peptides above 0.72. On this dataset, the best of the other methods achieved a sensitivity of 0.64. The NetCTL-1.2 method is available at <url>http://www.cbs.dtu.dk/services/NetCTL</url>.</p> <p>All used datasets are available at <url>http://www.cbs.dtu.dk/suppl/immunology/CTL-1.2.php</url>.</p
Requirements for measurement and validation of biochemical methane potential (BMP).
This document presents the minimal requirements for measurement and validation of biochemical methane potential (also called biomethane potential) (BMP) in batch tests. It represents the consensus of more than 50 biogas researchers. The list of requirements is the same as in the open-access commentary by Holliger et al. [2021]. For details on development of these requirements see the open-access papers Holliger et al. [2016] and Hafner et al. [2020c]
The Occurrence of Rocky Habitable-zone Planets around Solar-like Stars from Kepler Data
We present the occurrence rates for rocky planets in the habitable zones (HZs) of main-sequence dwarf stars based on the Kepler DR25 planet candidate catalog and Gaia-based stellar properties. We provide the first analysis in terms of star-dependent instellation flux, which allows us to track HZ planets. We define η⊕ as the HZ occurrence of planets with radii between 0.5 and 1.5 R⊕ orbiting stars with effective temperatures between 4800 and 6300 K. We find that η⊕ for the conservative HZ is between 0.37^(+0.48)_(−0.21) (errors reflect 68% credible intervals) and 0.60^(+0.90)_(−0.36) planets per star, while the optimistic HZ occurrence is between 0.58^(+0.73)_(−0.33) and 0.88^(+1.28)_(−0.51) planets per star. These bounds reflect two extreme assumptions about the extrapolation of completeness beyond orbital periods where DR25 completeness data are available. The large uncertainties are due to the small number of detected small HZ planets. We find similar occurrence rates between using Poisson likelihood Bayesian analysis and using Approximate Bayesian Computation. Our results are corrected for catalog completeness and reliability. Both completeness and the planet occurrence rate are dependent on stellar effective temperature. We also present occurrence rates for various stellar populations and planet size ranges. We estimate with 95% confidence that, on average, the nearest HZ planet around G and K dwarfs is ~6 pc away and there are ~4 HZ rocky planets around G and K dwarfs within 10 pc of the Sun
The Occurrence of Rocky Habitable Zone Planets Around Solar-Like Stars from Kepler Data
We present occurrence rates for rocky planets in the habitable zones (HZ) of
main-sequence dwarf stars based on the Kepler DR25 planet candidate catalog and
Gaia-based stellar properties. We provide the first analysis in terms of
star-dependent instellation flux, which allows us to track HZ planets. We
define as the HZ occurrence of planets with radius between 0.5
and 1.5 orbiting stars with effective temperatures between 4800 K
and 6300 K. We find that for the conservative HZ is between
(errors reflect 68\% credible intervals) and
planets per star, while the optimistic HZ occurrence is
between and planets per star.
These bounds reflect two extreme assumptions about the extrapolation of
completeness beyond orbital periods where DR25 completeness data are available.
The large uncertainties are due to the small number of detected small HZ
planets. We find similar occurrence rates using both a Poisson likelihood
Bayesian analysis and Approximate Bayesian Computation. Our results are
corrected for catalog completeness and reliability. Both completeness and the
planet occurrence rate are dependent on stellar effective temperature. We also
present occurrence rates for various stellar populations and planet size
ranges. We estimate with confidence that, on average, the nearest HZ
planet around G and K dwarfs is about 6 pc away, and there are about 4 HZ rocky
planets around G and K dwarfs within 10 pc of the Sun.Comment: To appear in The Astronomical Journa
Enhancing Discovery of Genetic Variants for Posttraumatic Stress Disorder Through Integration of Quantitative Phenotypes and Trauma Exposure Information
Funding Information: This work was supported by the National Institute of Mental Health / U.S. Army Medical Research and Development Command (Grant No. R01MH106595 [to CMN, IL, MBS, KJRe, and KCK], National Institutes of Health (Grant No. 5U01MH109539 to the Psychiatric Genomics Consortium ), and Brain & Behavior Research Foundation (Young Investigator Grant [to KWC]). Genotyping of samples was provided in part through the Stanley Center for Psychiatric Genetics at the Broad Institute supported by Cohen Veterans Bioscience . Statistical analyses were carried out on the LISA/Genetic Cluster Computer ( https://userinfo.surfsara.nl/systems/lisa ) hosted by SURFsara. This research has been conducted using the UK Biobank resource (Application No. 41209). This work would have not been possible without the financial support provided by Cohen Veterans Bioscience, the Stanley Center for Psychiatric Genetics at the Broad Institute, and One Mind. Funding Information: MBS has in the past 3 years received consulting income from Actelion, Acadia Pharmaceuticals, Aptinyx, Bionomics, BioXcel Therapeutics, Clexio, EmpowerPharm, GW Pharmaceuticals, Janssen, Jazz Pharmaceuticals, and Roche/Genentech and has stock options in Oxeia Biopharmaceuticals and Epivario. In the past 3 years, NPD has held a part-time paid position at Cohen Veterans Bioscience, has been a consultant for Sunovion Pharmaceuticals, and is on the scientific advisory board for Sentio Solutions for unrelated work. In the past 3 years, KJRe has been a consultant for Datastat, Inc., RallyPoint Networks, Inc., Sage Pharmaceuticals, and Takeda. JLM-K has received funding and a speaking fee from COMPASS Pathways. MU has been a consultant for System Analytic. HRK is a member of the Dicerna scientific advisory board and a member of the American Society of Clinical Psychopharmacology Alcohol Clinical Trials Initiative, which during the past 3 years was supported by Alkermes, Amygdala Neurosciences, Arbor Pharmaceuticals, Dicerna, Ethypharm, Indivior, Lundbeck, Mitsubishi, and Otsuka. HRK and JG are named as inventors on Patent Cooperative Treaty patent application number 15/878,640, entitled “Genotype-guided dosing of opioid agonists,” filed January 24, 2018. RP and JG are paid for their editorial work on the journal Complex Psychiatry. OAA is a consultant to HealthLytix. All other authors report no biomedical financial interests or potential conflicts of interest. Funding Information: This work was supported by the National Institute of Mental Health/ U.S. Army Medical Research and Development Command (Grant No. R01MH106595 [to CMN, IL, MBS, KJRe, and KCK], National Institutes of Health (Grant No. 5U01MH109539 to the Psychiatric Genomics Consortium), and Brain & Behavior Research Foundation (Young Investigator Grant [to KWC]). Genotyping of samples was provided in part through the Stanley Center for Psychiatric Genetics at the Broad Institute supported by Cohen Veterans Bioscience. Statistical analyses were carried out on the LISA/Genetic Cluster Computer (https://userinfo.surfsara.nl/systems/lisa) hosted by SURFsara. This research has been conducted using the UK Biobank resource (Application No. 41209). This work would have not been possible without the financial support provided by Cohen Veterans Bioscience, the Stanley Center for Psychiatric Genetics at the Broad Institute, and One Mind. This material has been reviewed by the Walter Reed Army Institute of Research. There is no objection to its presentation and/or publication. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting true views of the U.S. Department of the Army or the Department of Defense. We thank the investigators who comprise the PGC-PTSD working group and especially the more than 206,000 research participants worldwide who shared their life experiences and biological samples with PGC-PTSD investigators. We thank Mark Zervas for his critical input. Full acknowledgments are in Supplement 1. MBS has in the past 3 years received consulting income from Actelion, Acadia Pharmaceuticals, Aptinyx, Bionomics, BioXcel Therapeutics, Clexio, EmpowerPharm, GW Pharmaceuticals, Janssen, Jazz Pharmaceuticals, and Roche/Genentech and has stock options in Oxeia Biopharmaceuticals and Epivario. In the past 3 years, NPD has held a part-time paid position at Cohen Veterans Bioscience, has been a consultant for Sunovion Pharmaceuticals, and is on the scientific advisory board for Sentio Solutions for unrelated work. In the past 3 years, KJRe has been a consultant for Datastat, Inc. RallyPoint Networks, Inc. Sage Pharmaceuticals, and Takeda. JLM-K has received funding and a speaking fee from COMPASS Pathways. MU has been a consultant for System Analytic. HRK is a member of the Dicerna scientific advisory board and a member of the American Society of Clinical Psychopharmacology Alcohol Clinical Trials Initiative, which during the past 3 years was supported by Alkermes, Amygdala Neurosciences, Arbor Pharmaceuticals, Dicerna, Ethypharm, Indivior, Lundbeck, Mitsubishi, and Otsuka. HRK and JG are named as inventors on Patent Cooperative Treaty patent application number 15/878,640, entitled ?Genotype-guided dosing of opioid agonists,? filed January 24, 2018. RP and JG are paid for their editorial work on the journal Complex Psychiatry. OAA is a consultant to HealthLytix. All other authors report no biomedical financial interests or potential conflicts of interest. Publisher Copyright: © 2021 Society of Biological PsychiatryBackground: Posttraumatic stress disorder (PTSD) is heritable and a potential consequence of exposure to traumatic stress. Evidence suggests that a quantitative approach to PTSD phenotype measurement and incorporation of lifetime trauma exposure (LTE) information could enhance the discovery power of PTSD genome-wide association studies (GWASs). Methods: A GWAS on PTSD symptoms was performed in 51 cohorts followed by a fixed-effects meta-analysis (N = 182,199 European ancestry participants). A GWAS of LTE burden was performed in the UK Biobank cohort (N = 132,988). Genetic correlations were evaluated with linkage disequilibrium score regression. Multivariate analysis was performed using Multi-Trait Analysis of GWAS. Functional mapping and annotation of leading loci was performed with FUMA. Replication was evaluated using the Million Veteran Program GWAS of PTSD total symptoms. Results: GWASs of PTSD symptoms and LTE burden identified 5 and 6 independent genome-wide significant loci, respectively. There was a 72% genetic correlation between PTSD and LTE. PTSD and LTE showed largely similar patterns of genetic correlation with other traits, albeit with some distinctions. Adjusting PTSD for LTE reduced PTSD heritability by 31%. Multivariate analysis of PTSD and LTE increased the effective sample size of the PTSD GWAS by 20% and identified 4 additional loci. Four of these 9 PTSD loci were independently replicated in the Million Veteran Program. Conclusions: Through using a quantitative trait measure of PTSD, we identified novel risk loci not previously identified using prior case-control analyses. PTSD and LTE have a high genetic overlap that can be leveraged to increase discovery power through multivariate methods.publishersversionpublishe
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