155 research outputs found
New constraints on cosmological modified gravity theories from anisotropic three-point correlation functions of BOSS DR12 galaxies
We report a new test of modified gravity theories using the large-scale
structure of the Universe. This paper is the first attempt to (1) apply a joint
analysis of the anisotropic components of galaxy two- and three-point
correlation functions (2 and 3PCFs) to actual galaxy data and (2) constrain the
nonlinear effects of degenerate higher-order scalar-tensor (DHOST) theories on
cosmological scales. Applying this analysis to the Baryon Oscillation
Spectroscopic Survey (BOSS) data release 12, we obtain the lower bounds of
and at the confidence
level on the parameters characterising the time evolution of the tidal and
shift terms of the second-order velocity field. These constraints are
consistent with GR predictions of and .
Moreover, they represent a -fold and -fold improvement, respectively,
over the joint analysis with only the isotropic 3PCF. We ensure the validity of
our results by investigating various quantities, including theoretical models
of the 3PCF, window function corrections, cumulative , Fisher
matrices, and statistical scattering effects of mock simulation data. We also
find statistically significant discrepancies between the BOSS data and the
Patchy mocks for the 3PCF measurement. Finally, we package all of our 3PCF
analysis codes under the name \textsc{HITOMI} and make them publicly available
so that readers can reproduce all the results of this paper and easily apply
them to ongoing future galaxy surveys.Comment: 60 pages, 21 figures, 22 tables; a set of codes for data analysis is
publicly available at https://github.com/naonori/hitomi.gi
First test of the consistency relation for the large-scale structure using the anisotropic three-point correlation function of BOSS DR12 galaxies (An explanatory video is available at https://youtu.be/Zi36ooLPhss.)
We present, for the first time, an observational test of the consistency
relation for the large-scale structure (LSS) of the Universe through a joint
analysis of the anisotropic two- and three-point correlation functions (2PCF
and 3PCF) of galaxies. We parameterise the breakdown of the LSS consistency
relation in the squeezed limit by , which represents the ratio of
the coefficients of the shift terms in the second-order density and velocity
fluctuations. is a sufficient condition under which the LSS
consistency relation is violated. A novel aspect of this work is that we
constrain by obtaining information about the nonlinear velocity
field from the quadrupole component of the 3PCF without taking the squeezed
limit. Using the galaxy catalogues in the Baryon Oscillation Spectroscopic
Survey (BOSS) Data Release 12, we obtain ,
indicating that there is no violation of the LSS consistency relation in our
analysis within the statistical errors. Our parameterisation is general enough
that our constraint can be applied to a wide range of theories, such as
multicomponent fluids, modified gravity theories, and their associated galaxy
bias effects. Our analysis opens a new observational window to test the
fundamental physics using the anisotropic higher-order correlation functions of
galaxy clustering.Comment: 17 pages, 6 figures. Explanatory videos are available in several
languages: https://youtu.be/Zi36ooLPhss (English),
https://youtu.be/d2ZamcDt6hs (French), https://youtu.be/iSm5yPWmZ9c
(Spanish), https://youtu.be/Go7ox-ciHIc (German),
https://youtu.be/6Ith7cE723o (Chinese), and https://youtu.be/rH9-C3eKoYc
(English with my voice
Bubble burst as jamming phase transition
Recently research on bubble and its burst attract much interest of
researchers in various field such as economics and physics. Economists have
been regarding bubble as a disorder in prices. However, this research strategy
has overlooked an importance of the volume of transactions. In this paper, we
have proposed a bubble burst model by focusing the transactions incorporating a
traffic model that represents spontaneous traffic jam. We find that the
phenomenon of bubble burst shares many similar properties with traffic jam
formation by comparing data taken from US housing market. Our result suggests
that the transaction could be a driving force of bursting phenomenon.Comment: 9 pages,12 figure
Primordial magnetic fields from second-order cosmological perturbations: Tight coupling approximation
We explore the possibility of generating large-scale magnetic fields from
second-order cosmological perturbations during the pre-recombination era. The
key process for this is Thomson scattering between the photons and the charged
particles within the cosmic plasma. To tame the multi-component interacting
fluid system, we employ the tight coupling approximation. It is shown that the
source term for the magnetic field is given by the vorticity, which signals the
intrinsically second-order quantities, and the product of the first order
perturbations. The vorticity itself is sourced by the product of the
first-order quantities in the vorticity evolution equation. The magnetic fields
generated by this process are estimated to be Gauss on the
horizon scale at the recombination epoch. Although our rough estimate suggests
that the current generation mechanism can work even on smaller scales, more
careful investigation is needed to make clear whether it indeed works in a wide
range of spatial scales.Comment: 10pages, minor corrections, accepted for publication in Class. Quant.
Gra
The process of displacing the single-stranded DNA-binding protein from single-stranded DNA by RecO and RecR proteins
The regions of single-stranded (ss) DNA that result from DNA damage are immediately coated by the ssDNA-binding protein (SSB). RecF pathway proteins facilitate the displacement of SSB from ssDNA, allowing the RecA protein to form protein filaments on the ssDNA region, which facilitates the process of recombinational DNA repair. In this study, we examined the mechanism of SSB displacement from ssDNA using purified Thermus thermophilus RecF pathway proteins. To date, RecO and RecR are thought to act as the RecOR complex. However, our results indicate that RecO and RecR have distinct functions. We found that RecR binds both RecF and RecO, and that RecO binds RecR, SSB and ssDNA. The electron microscopic studies indicated that SSB is displaced from ssDNA by RecO. In addition, pull-down assays indicated that the displaced SSB still remains indirectly attached to ssDNA through its interaction with RecO in the RecO-ssDNA complex. In the presence of both SSB and RecO, the ssDNA-dependent ATPase activity of RecA was inhibited, but was restored by the addition of RecR. Interestingly, the interaction of RecR with RecO affected the ssDNA-binding properties of RecO. These results suggest a model of SSB displacement from the ssDNA by RecF pathway proteins
Degradation of Mutant Protein Aggregates within the Endoplasmic Reticulum of Vasopressin Neurons
Misfolded or unfolded proteins in the ER are said to be degraded only after translocation or isolation from the ER. Here, we describe a mechanism by which mutant proteins are degraded within the ER. Aggregates of mutant arginine vasopressin (AVP) precursor were confined to ER-associated compartments (ERACs) connected to the ER in AVP neurons of a mouse model of familial neurohypophysial diabetes insipidus. The ERACs were enclosed by membranes, an ER chaperone and marker protein of phagophores and autophagosomes were expressed around the aggregates, and lysosomes fused with the ERACs. Moreover, lysosome-related molecules were present within the ERACs, and aggregate degradation within the ERACs was dependent on autophagic-lysosomal activity. Thus, we demonstrate that protein aggregates can be degraded by autophagic-lysosomal machinery within specialized compartments of the ER
RGMa collapses the neuronal actin barrier against disease-implicated protein and exacerbates ALS
Repulsive guidance molecule A (RGMa) was originally identified as a neuronal growth cone–collapsing factor. Previous reports have demonstrated the multifunctional roles of RGMa mediated by neogenin1. However, the pathogenic involvement of RGMa in amyotrophic lateral sclerosis (ALS) remains unclear. Here, we demonstrated that RGMa concentration was elevated in the cerebrospinal fluid of both patients with ALS and transgenic mice overexpressing the mutant human superoxide dismutase1 (mSOD1 mice). Treatment with humanized anti-RGMa monoclonal antibody ameliorated the clinical symptoms in mSOD1 mice. Histochemical analysis revealed that the anti-RGMa antibody significantly decreased mutant SOD1 protein accumulation in the motor neurons of mSOD1 mice via inhibition of actin depolymerization. In vitro analysis revealed that the anti-RGMa antibody inhibited the cellular uptake of the mutant SOD1 protein, presumably by reinforcing the neuronal actin barrier. Collectively, these data suggest that RGMa leads to the collapse of the neuronal actin barrier and promotes aberrant protein deposition, resulting in exacerbation of the ALS pathology.Shimizu Mikito, Shiraishi Naoyuki, Tada Satoru, et al. RGMa collapses the neuronal actin barrier against disease-implicated protein and exacerbates ALS. Science Advances 9, 686 (2023); https://doi.org/10.1126/sciadv.adg3193
Adalimumab Dose-Escalation Therapy Is Effective in Refractory Crohn’s Disease Patients with Loss of Response to Adalimumab, Especially in Cases without Previous Infliximab Treatment
Background/Aims: Adalimumab dose escalation is one of the most important options in refractory Crohn’s disease patients with loss of response to adalimumab. The goal of this study was to evaluate the effectiveness of adalimumab dose escalation in Crohn’s disease patients with loss of response to adalimumab, since there are few reports of adalimumab dose escalation, especially in East Asia. Methods: The clinical response to adalimumab dose escalation in Crohn’s disease patients with loss of response to adalimumab was evaluated retrospectively, using the Crohn’s disease activity index score, serum C-reactive protein levels, and endoscopic analyses. Results: Of the 203 Crohn’s disease patients treated with anti-tumor necrosis factor, 14 refractory Crohn’s disease patients with loss of response to adalimumab received adalimumab dose-escalation therapy. The C-reactive protein level was significantly reduced from the start to weeks 12 and 52 of adalimumab dose escalation in the whole group, although there were no significant reductions of Crohn’s disease activity index scores. Both Crohn’s disease activity index scores and C-reactive protein levels were significantly reduced from the start to weeks 12 and 52 of adalimumab dose escalation in patients without previous infliximab treatment, although C-reactive protein levels were positive in all cases with previous infliximab exposure at weeks 12 and 52. Endoscopic mucosal healing was achieved with adalimumab dose escalation in 2 cases without previous infliximab treatment. Conclusions: Adalimumab dose-escalation therapy is effective in refractory Crohn’s disease patients with loss of response to adalimumab, especially in cases without previous infliximab treatment
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