15 research outputs found
OSSOS VI. Striking Biases in the detection of large semimajor axis Trans-Neptunian Objects
The accumulating, but small, set of large semi-major axis trans-Neptunian
objects (TNOs) shows an apparent clustering in the orientations of their
orbits. This clustering must either be representative of the intrinsic
distribution of these TNOs, or else arise as a result of observation biases
and/or statistically expected variations for such a small set of detected
objects. The clustered TNOs were detected across different and independent
surveys, which has led to claims that the detections are therefore free of
observational bias. This apparent clustering has led to the so-called "Planet
9" hypothesis that a super-Earth currently resides in the distant solar system
and causes this clustering. The Outer Solar System Origins Survey (OSSOS) is a
large program that ran on the Canada-France-Hawaii Telescope from 2013--2017,
discovering more than 800 new TNOs. One of the primary design goals of OSSOS
was the careful determination of observational biases that would manifest
within the detected sample. We demonstrate the striking and non-intuitive
biases that exist for the detection of TNOs with large semi-major axes. The
eight large semi-major axis OSSOS detections are an independent dataset, of
comparable size to the conglomerate samples used in previous studies. We
conclude that the orbital distribution of the OSSOS sample is consistent with
being detected from a uniform underlying angular distribution.Comment: Accepted for publicatio
The Role of Innate APOBEC3G and Adaptive AID Immune Responses in HLA-HIV/SIV Immunized SHIV Infected Macaques
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Direct Phenotypical and Functional Dysregulation of Primary Human B Cells by Human Immunodeficiency Virus (HIV) Type 1 In Vitro
BACKGROUND: Human immunodeficiency virus type 1 (HIV-1) induces a general dysregulation of immune system. Dysregulation of B cell compartment is generally thought to be induced by HIV-related immune activation and lymphopenia. However, a direct influence of HIV-1 particles on B cells was recently proposed as the third pathway of B cells dysregulation. METHODS/PRINCIPAL FINDINGS: We evaluated the direct and specific consequences of HIV-1 contact on activation, survival, proliferation and phenotype of primary B cells in vitro. Moreover, we examined expression of activation-induced cytidine deaminase (AID) mRNA that is responsible for class switch recombination (CSR) and somatic hypermutation (SHM). Here, we report that changes observed in cellular proliferation, phenotypes and activation of B cells could be caused by direct contact between HIV-1 particles and primary B cells in vitro. Finally, direct HIV-1-derived B cells activation led to the increase of AID mRNA expression and its subsequent CSR function was detected in vitro. CONCLUSION/SIGNIFICANCE: We showed that HIV-1 could directly induce primary B cells dysregulation triggering phenotypical and functional abilities of B cells in vitro that could explain in some extent early B-cell abnormalities in HIV disease
A new high-perihelion a ~ 700 AU object in the distant Solar System
International audienceWe report the discovery of a trans-Neptunian object (TNO) plausibly diffusing out of the inner Oort Cloud reservoir. This TNO is on an orbit with q ~ 50 AU, a ~ 700 AU, the largest semi-major axis yet detected for an orbit with perihelion q beyond the q ≤ 38 zone of strong influence of Neptune, exceeding the semi-major axes of (90377) Sedna, 2012 VP113 and 2010 GB174. Such objects are rarely observed. Trans-Neptunian objects with these high orbital perihelia have no confirmed formation mechanism in the present planetary architecture of the Solar System. The orbit of this new TNO can be formed by inward diffusion of objects from a Galactic-tide-dominated population with a ~ 1000-2000 AU; the formation mechanism is highly inefficient, and would require on the order of a hundred times more objects in that population than in the a ~ 700 AU population. We also report colour and light curve measurements of the new TNO with Gemini North and Subaru-HSC. The longitude of the ascending node and argument of perihelion of this TNO's orbit have implications for the hypothesis of a ninth planet
A new high-perihelion a ~ 700 AU object in the distant Solar System
International audienceWe report the discovery of a trans-Neptunian object (TNO) plausibly diffusing out of the inner Oort Cloud reservoir. This TNO is on an orbit with q ~ 50 AU, a ~ 700 AU, the largest semi-major axis yet detected for an orbit with perihelion q beyond the q ≤ 38 zone of strong influence of Neptune, exceeding the semi-major axes of (90377) Sedna, 2012 VP113 and 2010 GB174. Such objects are rarely observed. Trans-Neptunian objects with these high orbital perihelia have no confirmed formation mechanism in the present planetary architecture of the Solar System. The orbit of this new TNO can be formed by inward diffusion of objects from a Galactic-tide-dominated population with a ~ 1000-2000 AU; the formation mechanism is highly inefficient, and would require on the order of a hundred times more objects in that population than in the a ~ 700 AU population. We also report colour and light curve measurements of the new TNO with Gemini North and Subaru-HSC. The longitude of the ascending node and argument of perihelion of this TNO's orbit have implications for the hypothesis of a ninth planet
Immediate and Delayed Consequences of Xanomeline Wash-Resistant Binding at the M3 Muscarinic Receptor
Monetary conditions and banks’ behaviour in the Czech Republic
This paper examines the impact of monetary conditions on the risk-taking behaviour of banks in the Czech Republic by analysing the comprehensive credit register of the Czech National Bank. Our duration analysis indicates that expansionary monetary conditions promote risk-taking among banks. At the same time, a lower interest rate during the life of a loan reduces its riskiness. While seeking to assess the association between banks’ appetite for risk and the short-term interest rate we answer a set of questions related to the difference between higher liquidity versus credit risk and the effect of the policy rate conditioned on bank and borrower characteristics.This work was supported by the Czech national Bank (Research Project No. C4/2009) and the Grant Agency of the Czech Republic projects GA CR No. 14-02108S and No. P402/12/G097)