101 research outputs found
Model-independent search for anisotropies in stochastic gravitational-wave backgrounds and application to LIGO-Virgo's first three observing Runs
A stochastic gravitational-wave (GW) background consists of a large number of
weak, independent and uncorrelated events of astrophysical or cosmological
origin. The GW power on the sky is assumed to contain anisotropies on top of an
isotropic component, i.e., the angular monopole. Complementary to the
LIGO--Virgo--KAGRA (LVK) searches, we develop an efficient analysis pipeline to
compute the maximum-likelihood anisotropic sky maps in stochastic backgrounds
directly in the sky pixel domain using data folded over one sidereal day. We
invert the full pixel-pixel correlation matrix in map-making of the GW sky, up
to an optimal eigenmode cutoff decided systematically using simulations. In
addition to modeled mapping, we implement a model-independent method to probe
spectral shapes of stochastic backgrounds. Using data from LIGO--Virgo's first
three observing runs, we obtain upper limits on anisotropies as well as the
isotropic monopole as a limiting case, consistent with the LVK results. We also
set constraints on the spectral shape of the stochastic background using this
novel model-independent method.Comment: 16 pages, 9 figure
Occurrence of Compact Groups of Galaxies through Cosmic Time
We use the outputs of a semianalytical model of galaxy formation run on the Millennium Simulation to investigate the prevalence of 3D compact groups (CGs) of galaxies from z = 11 to 0. Our publicly available code identifies CGs using the 3D galaxy number density, the mass ratio of secondary+tertiary to the primary member, mass density in a surrounding shell, the relative velocities of candidate CG members, and a minimum CG membership of three. We adopt "default" values for the first three criteria, representing the observed population of Hickson CGs at z = 0. The percentage of nondwarf galaxies (M > 5 × 10^8 h^(−1) M ⊙) in CGs peaks near z ~ 2 for the default set and in the range of z ~ 1–3 for other parameter sets. This percentage declines rapidly at higher redshifts (z ≳ 4), consistent with the galaxy population as a whole being dominated by low-mass galaxies excluded from this analysis. According to the most liberal criteria, ≾3% of nondwarf galaxies are members of CGs at the redshift where the CG population peaks. Our default criteria result in a population of CGs at z < 0.03 with number densities and sizes consistent with Hickson CGs. Tracking identified CG galaxies and merger products to z = 0, we find that ≾16% of nondwarf galaxies have been CG members at some point in their history. Intriguingly, the great majority (96%) of z = 2 CGs have merged to a single galaxy by z = 0. There is a discrepancy in the velocity dispersions of Millennium Simulation CGs compared to those in observed CGs, which remains unresolved
The Occurrence of Compact Groups of Galaxies Through Cosmic Time
We use the outputs of a semi-analytical model of galaxy formation run on the
Millennium Simulation to investigate the prevalence of 3D compact groups (CGs)
of galaxies from to 0. Our publicly available code identifies CGs
using the 3D galaxy number density, the mass ratio of secondary+tertiary to the
primary member, mass density in a surrounding shell, the relative velocities of
candidate CG members, and a minimum CG membership of three. We adopt "default"
values for the first three criteria, representing the observed population of
Hickson CGs at . The percentage of non-dwarf galaxies () in CGs peaks near for the default set, and
between for other parameter sets. This percentage declines
rapidly at higher redshifts (), consistent with the galaxy
population as a whole being dominated by low-mass galaxies excluded from this
analysis. According to the most liberal criteria, of non-dwarf
galaxies are members of CGs at the redshift where the CG population peaks. Our
default criteria result in a population of CGs at with number
densities and sizes consistent with Hickson CGs. Tracking identified CG
galaxies and merger products to , we find that of
non-dwarf galaxies have been CG members at some point in their history.
Intriguingly, the great majority () of CGs have merged to a
single galaxy by . There is a discrepancy in the velocity dispersions of
Millennium Simulation CGs compared to those in observed CGs, which remains
unresolved.Comment: Revised version to match published version. Uses likeapj.cls
(v1.1.5), likeapj.bst style files, 11 pages, 7 figures, 1 table. Compact
group detection code available at https://github.com/cdw9bf/CompactGroup ;
LaTex style files available at
https://github.com/qtast/likeapj/releases/lates
Podwyższone stężenia lipokaliny-2 w surowicy krwi są związane ze wskaźnikami metabolizmu glukozy i metabolizmu kostnego w przebiegu cukrzycy typu 2
Introduction: The role of lipocalin 2 (LCN2) in type 2 diabetes mellitus (T2DM) needs to be fully elucidated. Moreover, bone has been demonstrated to modulate glucose metabolism via LCN2. We thus performed this study to investigate the associations of LCN2 with indexes of glucose metabolism in T2DM. The associations of LCN2 with bone metabolism were examined concurrently.
Material and methods: Total 288 Chinese Han subjects entered in this study including 146 patients with T2DM and 142 subjects with normal glucose tolerance. Insulin resistance was assessed by HOMA-IR andWstęp: Wyjaśnienie roli lipokaliny-2 (lipocalin 2; LCN2) w przebiegu cukrzycy typu 2 jest niezbędne, w szczególności, że zostało dowiedzione, iż kość moduluje metabolizm glukozy za pośrednictwem LCN2. Niniejsze badanie przeprowadzono, aby zbadać, w jaki sposób LCN2 jest powiązana ze wskaźnikami metabolizmu glukozy w przebiegu cukrzycy typu 2. Jednocześnie zbadano powiązania LCN2 z metabolizmem kostnym.
Materiał i metody: W badaniu wzięło udział 288 Chińczyków Han, w tym 146 pacjentów z cukrzycą typu 2 i 142 pacjentów z prawidłową tolerancją glukozy. Insulinooporność oceniano za pomocą wskaźnika HOMA-IR, natomiast funkcję komórek beta trzustki za pomocą HOMA-β. W przypadku pacjentów z cukrzycą typu 2 oznaczano również markery obrotu kostnego, N-końcowy propeptyd prokolagenu typu I, C-końcowy usieciowany telopeptyd łańcucha alfa kolagenu typu I, gęstość mineralną kości (bone mineral density; BMD) odcinka lędźwiowego kręgosłupa i szyjki kości udowej.
Wyniki: Stężenia LCN2 w surowicy krwi w przebiegu cukrzycy typu 2 były wyższe niż u osób z prawidłową tolerancją glukozy (p = 0,005). Ponadto, LCN2 była dodatnio skorelowana ze stężeniem insuliny w surowicy krwi na czczo (r = 0,262, p = 0,001), wskaźnikiem HOMA-IR (r = 0,185, p = 0,026) i HOMA-β (r = 0,306, p < 0,001), odpowiednio, oraz ujemnie skorelowana z osoczowym stężeniem glukozy na czczo (r = –0,218, p = 0,006). Dodatkowo, BMD szyjki kości udowej (β = –0,176, p = 0,033), N-końcowy propeptyd prokolagenu typu I (β = 0,181, p = 0,026) oraz C-końcowy usieciowany telopeptyd łańcucha alfa kolagenu typu I (β = –0,168, p = 0,037) były niezależnymi czynnikami predykcyjnymi dla LCN2 w przebiegu cukrzycy typu 2.
Wnioski: Lipokalina-2 byÅ‚a powiÄ…zana ze wskaźnikami metabolizmu glukozy. Ponadto, BMD oraz markery obrotu kostnego byÅ‚y nieÂzależnymi czynnikami predykcyjnymi dla LCN2 w przebiegu cukrzycy typu 2. Można sÄ…dzić, że LCN2 może odgrywać rolÄ™ w procesie wzajemnego wpÅ‚ywu homeostazy koÅ›ci i homeostazy glukozy
Occurrence of Compact Groups of Galaxies through Cosmic Time
We use the outputs of a semianalytical model of galaxy formation run on the Millennium Simulation to investigate the prevalence of 3D compact groups (CGs) of galaxies from z = 11 to 0. Our publicly available code identifies CGs using the 3D galaxy number density, the mass ratio of secondary+tertiary to the primary member, mass density in a surrounding shell, the relative velocities of candidate CG members, and a minimum CG membership of three. We adopt "default" values for the first three criteria, representing the observed population of Hickson CGs at z = 0. The percentage of nondwarf galaxies (M > 5 × 10^8 h^(−1) M ⊙) in CGs peaks near z ~ 2 for the default set and in the range of z ~ 1–3 for other parameter sets. This percentage declines rapidly at higher redshifts (z ≳ 4), consistent with the galaxy population as a whole being dominated by low-mass galaxies excluded from this analysis. According to the most liberal criteria, ≾3% of nondwarf galaxies are members of CGs at the redshift where the CG population peaks. Our default criteria result in a population of CGs at z < 0.03 with number densities and sizes consistent with Hickson CGs. Tracking identified CG galaxies and merger products to z = 0, we find that ≾16% of nondwarf galaxies have been CG members at some point in their history. Intriguingly, the great majority (96%) of z = 2 CGs have merged to a single galaxy by z = 0. There is a discrepancy in the velocity dispersions of Millennium Simulation CGs compared to those in observed CGs, which remains unresolved
The GstLAL Search Analysis Methods for Compact Binary Mergers in Advanced LIGO's Second and Advanced Virgo's First Observing Runs
After their successful first observing run (September 12, 2015 - January 12,
2016), the Advanced LIGO detectors were upgraded to increase their sensitivity
for the second observing run (November 30, 2016 - August 26, 2017). The
Advanced Virgo detector joined the second observing run on August 1, 2017. We
discuss the updates that happened during this period in the GstLAL-based
inspiral pipeline, which is used to detect gravitational waves from the
coalescence of compact binaries both in low latency and an offline
configuration. These updates include deployment of a zero-latency whitening
filter to reduce the over-all latency of the pipeline by up to 32 seconds,
incorporation of the Virgo data stream in the analysis, introduction of a
single-detector search to analyze data from the periods when only one of the
detectors is running, addition of new parameters to the likelihood ratio
ranking statistic, increase in the parameter space of the search, and
introduction of a template mass-dependent glitch-excision thresholding method.Comment: 12 pages, 7 figures, to be submitted to Phys. Rev. D, comments
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The GstLAL template bank for spinning compact binary mergers in the second observation run of Advanced LIGO and Virgo
We describe the methods used to construct the aligned-spin template bank of
gravitational waveforms used by the GstLAL-based inspiral pipeline to analyze
data from the second observing run of Advanced LIGO and Virgo. The bank expands
upon the parameter space covered during the first observing run, including
coverage for merging compact binary systems with total mass between 2
and 400 and mass ratios between 1 and
97.989. Thus the systems targeted include merging neutron star-neutron star
systems, neutron star-black hole binaries, and black hole-black hole binaries
expanding into the intermediate-mass range. Component masses less than 2
have allowed (anti-)aligned spins between while
component masses greater than 2 have allowed
(anti-)aligned between . The bank placement technique combines a
stochastic method with a new grid-bank method to better isolate noisy
templates, resulting in a total of 677,000 templates.Comment: 9 pages, 13 figure
Abdomen anatomic characteristics on CT scans as predictive markers for short-term complications following radical resection of colorectal cancer
BackgroundPrediction and management of short-term postoperative complications in patients with colorectal cancer are essential in postoperative rehabilitation. Through CT scan images, we can easily measure some parameters of abdomen anatomic characteristics. This study aimed to assess whether there is a relationship between the abdomen anatomic characteristics and short-term postoperative complications.Materials and methodsWe conducted a retrospective study. Eighty patients in each complication group and non-complication group were recruited with propensity score match. Demographics, perioperative laboratory results and surgical information were collected and compared between groups with univariate analysis. Significant elements were brought into subsequent logistic regression analysis and ROC analysis for further identification.ResultsUnivariate analysis showed that preoperative white blood cells, preoperative neutrophil counts, rectus abdominis thickness (RAT), subcutaneous fat thickness (SFT), and abdomen depth (AD) were significantly different between the complication group and non-complication group. Logistic regression analysis demonstrated that higher RAT (p = 0.002), SFT (p < 0.001) and AD (p < 0.001) independently predicted the incidence of short-term postoperative complications.ConclusionsIn this study on patients undergoing radical resection of colorectal cancer, abdomen anatomic characteristics including higher RAT, SFT and AD are associated with an increased risk of short-term postoperative complications
Phenotypic and functional alteration of CD45+ immune cells in the decidua of preeclampsia patients analyzed by mass cytometry (CyTOF)
Preeclampsia (PE) is a severe placenta-related pregnancy disease that has been associated with maternal systemic inflammation and immune system disorders. However, the distribution and functional changes in immune cells of the maternal–placental interface have not been well characterized. Herein, cytometry by time-of-flight mass spectrometry (CyTOF) was used to investigate the immune atlas at the decidua, which was obtained from four PE patients and four healthy controls. Six superclusters were identified, namely, T cells, B cells, natural killer (NK) cells, monocytes, granulocytes, and others. B cells were significantly decreased in the PE group, among which the reduction in CD27+CD38+ regulatory B cell (Breg)-like cells may stimulate immune activation in PE. The significantly increased migration of B cells could be linked to the significantly overexpressed chemokine C-X-C receptor 5 (CXCR5) in the PE group, which may result in the production of excessive autoantibodies and the pathogenesis of PE. A subset of T cells, CD11c+CD8+ T cells, was significantly decreased in PE and might lead to sustained immune activation in PE patients. NK cells were ultimately separated into four subsets. The significant reduction in a novel subset of NK cells (CD56-CD49a-CD38+) in PE might have led to the failure to suppress inflammation at the maternal–fetal interface during PE progression. Moreover, the expression levels of functional markers were significantly altered in the PE group, which also inferred that shifts in the decidual immune state contributed to the development of PE and might serve as potential treatment targets. This is a worthy attempt to elaborate the differences in the phenotype and function of CD45+ immune cells in the decidua between PE and healthy pregnancies by CyTOF, which contributes to understand the pathogenesis of PE, and the altered cell subsets and markers may inspire the immune modulatory therapy for PE
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