67 research outputs found
Long-Term Stability of Radio Sources in VLBI Analysis
Positional stability of radio sources is an important requirement for modeling of only one source position for the complete length of VLBI data of presently more than 20 years. The stability of radio sources can be verified by analyzing time series of radio source coordinates. One approach is a statistical test for normal distribution of residuals to the weighted mean for each radio source component of the time series. Systematic phenomena in the time series can thus be detected. Nevertheless, an inspection of rate estimation and weighted root-mean-square (WRMS) variations about the mean is also necessary. On the basis of the time series computed by the BKG group in the frame of the ICRF2 working group, 226 stable radio sources with an axis stability of 10 as could be identified. They include 100 ICRF2 axes-defining sources which are determined independently of the method applied in the ICRF2 working group. 29 stable radio sources with a source structure index of less than 3.0 can also be used to increase the number of 295 ICRF2 defining sources
The BKG/IGGB VLBI Analysis Center
In 2012, the activities of the BKG/IGGB VLBI Analysis Center, as in previous years, consisted of routine computations of Earth orientation parameter (EOP) time series and of a number of research topics in geodetic VLBI. The VLBI group at BKG continued its regular submissions of time series of tropospheric parameters and the generation of daily SINEX (Solution INdependent EXchange format) files. Quarterly updated solutions have been computed to produce terrestrial reference frame (TRF) and celestial reference frame (CRF) realizations. Routine computations of the UT1-UTC Intensive observations include all sessions of the Kokee-Wettzell and Tsukuba-Wettzell baselines and the networks Kokee-Svetloe-Wettzell and Ny-degAlesund-Tsukuba-Wettzell. The VLBI group at BKG developed a procedure to get the most probable station positions of Tsukuba after the earthquake on March 11, 2011 for the epochs of the Intensive sessions. The analysis of the Intensive sessions with station Tsukuba could be resumed in February 2012. At IGGB, the emphasis has been placed on individual research topics
Self-supervised motion descriptor for cardiac phase detection in 4D CMR based on discrete vector field estimations
Cardiac magnetic resonance (CMR) sequences visualise the cardiac function
voxel-wise over time. Simultaneously, deep learning-based deformable image
registration is able to estimate discrete vector fields which warp one time
step of a CMR sequence to the following in a self-supervised manner. However,
despite the rich source of information included in these 3D+t vector fields, a
standardised interpretation is challenging and the clinical applications remain
limited so far. In this work, we show how to efficiently use a deformable
vector field to describe the underlying dynamic process of a cardiac cycle in
form of a derived 1D motion descriptor. Additionally, based on the expected
cardiovascular physiological properties of a contracting or relaxing ventricle,
we define a set of rules that enables the identification of five cardiovascular
phases including the end-systole (ES) and end-diastole (ED) without the usage
of labels. We evaluate the plausibility of the motion descriptor on two
challenging multi-disease, -center, -scanner short-axis CMR datasets. First, by
reporting quantitative measures such as the periodic frame difference for the
extracted phases. Second, by comparing qualitatively the general pattern when
we temporally resample and align the motion descriptors of all instances across
both datasets. The average periodic frame difference for the ED, ES key phases
of our approach is , which is slightly better
than the inter-observer variability (, ) and the
supervised baseline method (, ). Code and labels
will be made available on our GitHub repository.
https://github.com/Cardio-AI/cmr-phase-detectionComment: accepted for the STACOM2022 workshop @ MICCAI202
Personality structure and social style in macaques.
Why regularities in personality can be described with particular dimensions is a basic question in differential psychology. Nonhuman primates can also be characterized in terms of personality structure. Comparative approaches can help reveal phylogenetic constraints and social and ecological patterns associated with the presence or absence of specific personality dimensions. We sought to determine how different personality structures are related to interspecific variation in social style. Specifically, we examined this question in 6 different species of macaques, because macaque social style is well characterized and can be categorized on a spectrum of despotic (Grade 1) versus tolerant (Grade 4) social styles. We derived personality structures from adjectival ratings of Japanese (Macaca fuscata; Grade 1), Assamese (M. assamensis; Grade 2), Barbary (M. sylvanus; Grade 3), Tonkean (M. tonkeana; Grade 4), and crested (M. nigra; Grade 4) macaques and compared these species with rhesus macaques (M. mulatta; Grade 1) whose personality was previously characterized. Using a nonparametric method, fuzzy set analysis, to identify commonalities in personality dimensions across species, we found that all but 1 species exhibited consistently defined Friendliness and Openness dimensions, but that similarities in personality dimensions capturing aggression and social competence reflect similarities in social styles. These findings suggest that social and phylogenetic relationships contribute to the origin, maintenance, and diversification of personality
Consistency of parameters derived from global SLR, VLBI and GNSS solutions when using non-tidal loading deformation on the observation level
HLA-DRB3/4/5 Matching Improves Outcome of Unrelated Hematopoietic Stem Cell Transplantation
The HLA-DRB3/4/5 loci are closely linked to the HLA-DRB1 gene. Mismatches in these
loci occur with a frequency of about 8%–12% in otherwise 10/10 HLA-matched transplant
pairs. There is preliminary evidence that these disparities may associate with increased
acute graft-versus-host disease (GvHD) rates. The aim of this study was to analyze a large
cohort of German patients and their donors for HLA-DRB3/4/5 compatibility and to
correlate the HLA-DRB3/4/5 matching status with the outcome of unrelated
hematopoietic stem cell transplantation (uHSCT). To this end, 3,410 patients and their
respective donors were HLA-DRB3/4/5 and HLA-DPB1 typed by amplicon-based nextgeneration
sequencing (NGS). All patients included received their first allogeneic
transplant for malignant hematologic diseases between 2000 and 2014. Mismatches in
the antigen recognition domain (ARD) of HLA-DRB3/4/5 genes were correlated with
clinical outcome. HLA-DRB3/4/5 incompatibility was seen in 12.5% (n = 296) and 17.8%
(n = 185) of the 10/10 and 9/10 HLA-matched cases, respectively. HLA-DRB3/4/5
mismatches in the ARD associated with a worse overall survival (OS), as shown in
univariate (5-year OS: 46.1% vs. 39.8%, log-rank p = 0.038) and multivariate analyses
[hazard ratio (HR) 1.25, 95% CI 1.02–1.54, p = 0.034] in the otherwise 10/10 HLAmatched
subgroup. The worse outcome was mainly driven by a significantly higher nonrelapse
mortality (HR 1.35, 95% CI 1.05–1.73, p = 0.017). In the 9/10 HLA-matched
cases, the effect was not statistically significant. Our study results suggest that
mismatches within the ARD of HLA-DRB3/4/5 genes significantly impact the outcome
of otherwise fully matched uHSCT and support their consideration upon donor selection in
the future
HLA-DRB3/4/5 Matching Improves Outcome of Unrelated Hematopoietic Stem Cell Transplantation
The HLA-DRB3/4/5 loci are closely linked to the HLA-DRB1 gene. Mismatches in these
loci occur with a frequency of about 8%–12% in otherwise 10/10 HLA-matched transplant
pairs. There is preliminary evidence that these disparities may associate with increased
acute graft-versus-host disease (GvHD) rates. The aim of this study was to analyze a large
cohort of German patients and their donors for HLA-DRB3/4/5 compatibility and to
correlate the HLA-DRB3/4/5 matching status with the outcome of unrelated
hematopoietic stem cell transplantation (uHSCT). To this end, 3,410 patients and their
respective donors were HLA-DRB3/4/5 and HLA-DPB1 typed by amplicon-based nextgeneration
sequencing (NGS). All patients included received their first allogeneic
transplant for malignant hematologic diseases between 2000 and 2014. Mismatches in
the antigen recognition domain (ARD) of HLA-DRB3/4/5 genes were correlated with
clinical outcome. HLA-DRB3/4/5 incompatibility was seen in 12.5% (n = 296) and 17.8%
(n = 185) of the 10/10 and 9/10 HLA-matched cases, respectively. HLA-DRB3/4/5
mismatches in the ARD associated with a worse overall survival (OS), as shown in
univariate (5-year OS: 46.1% vs. 39.8%, log-rank p = 0.038) and multivariate analyses
[hazard ratio (HR) 1.25, 95% CI 1.02–1.54, p = 0.034] in the otherwise 10/10 HLAmatched
subgroup. The worse outcome was mainly driven by a significantly higher nonrelapse
mortality (HR 1.35, 95% CI 1.05–1.73, p = 0.017). In the 9/10 HLA-matched
cases, the effect was not statistically significant. Our study results suggest that
mismatches within the ARD of HLA-DRB3/4/5 genes significantly impact the outcome
of otherwise fully matched uHSCT and support their consideration upon donor selection in
the future
Individual Facial Coloration in Male Eulemur fulvus rufus: A Condition-dependent Ornament?
Researchers studying individual variation in conspicuous skin coloration in primates have suggested that color indicates male quality. Although primate fur color can also be flamboyant, the potential condition dependence and thus signaling function of fur remains poorly studied. We studied sources of variation in sexually dichromatic facial hair coloration in red-fronted lemurs (Eulemur fulvus rufus). We collected data on 13 adult males in Kirindy Forest, Madagascar, during two study periods in 2006 and 2007, to determine whether variation in facial hair coloration correlates with male age, rank, androgen status, and reproductive success. We quantified facial hair coloration via standardized digital photographs of each male, assessed androgen status using fecal hormone measurements, and obtained data on reproductive success through genetic paternity analyses. Male facial hair coloration showed high individual variation, and baseline coloration was related to individual androgen status but not to any other parameter tested. Color did not reflect rapid androgen changes during the mating season. However, pronounced long-term changes in androgen levels between years were accompanied by changes in facial hair coloration. Our data suggest that facial hair coloration in red-fronted lemur males is under proximate control of androgens and may provide some information about male quality, but it does not correlate with dominance rank or male reproductive success
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