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Liquidity Traps, Learning and Stagnation
We examine global economic dynamics under learning in a New Keynesian model in which the interest-rate rule is subject to the zero lower bound. Under normal monetary and fiscal policy, the intended steady state is locally but not globally stable. Large pessimistic shocks to expectations can lead to deflationary spirals with falling prices and falling output. To avoid this outcome we recommend augmenting normal policies with aggressive monetary and fiscal policy that guarantee a lower bound on inflation. In contrast, policies geared toward ensuring an output lower bound are insufficient for avoiding deflationary spirals
Dynamic equilibrium correction modelling of yen Eurobond credit spreads
Understanding the long term relationship between the yields of risky and riskless bonds is a critical task for portfolio managers and policy makers. This study specifies an equilibrium correction model of the credit spreads between Japanese Government bonds (JGBs) and Japanese yen Eurobonds with high quality credit ratings. The empirical results indicate that the corporate bond yields are cointegrated with the otherwise equivalent JGB yields, with the spread defining the cointegration relation. In addition the results indicate that the equilibrium correction term is highly statistically significant in modelling credit spread changes. Another important factor is the risk-free interest rate with the negative sign, while there is little evidence of the contribution of the asset return to the behaviour of spreads.
The 1990 MB: The first Mars Trojan
Asteroid 1990 MB was discovered by D. H. Levy and H. E. Holt during the course of the Mars and Earth Crossing Asteroid and Comet Survey. An orbit based on a 9 day arc and the asteroid's location near Mars' L5 (trailing Lagrangean) longitude led E. Boswell to speculate that it might be in 1:1 resonance with Mars, analogous to the Trojan asteroids of Jupiter. Subsequent observations strengthened the possibility, and later calculations confirmed it. Thus 1990 MB is the first known asteroid in 1:1 resonance with a planet other than Jupiter. The existence of 1990 MB (a small body most likely between 2 and 4 km in diameter) provides remarkable confirmation of computer simulations. These self consistent n-body simulations demonstrated this sort of stability for Trojans of all the terrestrial planets over at least a 2 million year time base. The discovery of 1990 MB suggests that others of similar or smaller diameter may be found. Using hypothetical populations of Mars Trojans, their possible sky plane distributions were modeled as a first step in undertaking a systematic observational search of Mars' L4 and L5 libration regions
Gaia transient detection efficiency: hunting for nuclear transients
We present a study of the detectability of transient events associated with
galaxies for the Gaia European Space Agency astrometric mission. We simulated
the on-board detections, and on-ground processing for a mock galaxy catalogue
to establish the properties required for the discovery of transient events by
Gaia, specifically tidal disruption events (TDEs) and supernovae (SNe).
Transients may either be discovered by the on-board detection of a new source
or by the brightening of a previously known source. We show that Gaia
transients can be identified as new detections on-board for offsets from the
host galaxy nucleus of 0.1--0.5,arcsec, depending on magnitude and scanning
angle. The Gaia detection system shows no significant loss of SNe at close
radial distances to the nucleus. We used the detection efficiencies to predict
the number of transients events discovered by Gaia. For a limiting magnitude of
19, we expect around 1300 SNe per year: 65% SN Ia, 28% SN II and 7% SN Ibc, and
~20 TDEs per year.Comment: 17 pages, 10 figures, accepted by MNRA
Cervicovaginal Complement Activation and Microbiota During Pregnancy and in Parturition
BackgroundVaginal microbiome and the local innate immune defense, including the complement system, contribute to anti- and proinflammatory homeostasis during pregnancy and parturition. The relationship between commensal vaginal bacteria and complement activation during pregnancy and delivery is not known. ObjectiveTo study the association of the cervicovaginal microbiota composition to activation and regulation of the complement system during pregnancy and labor. Study designWe recruited women during late pregnancy (weeks 41 + 5 to 42 + 0, n=48) and women in active labor (weeks 38 + 4 to 42 + 2, n=25). Mucosal swabs were taken from the external cervix and lateral fornix of the vagina. From the same sampling site, microbiota was analyzed with 16S RNA gene amplicon sequencing. A Western blot technique was used to detect complement C3, C4 and factor B activation and presence of complement inhibitors. For semiquantitative analysis, the bands of the electrophoresed proteins in gels were digitized on a flatbed photo scanner and staining intensities were analyzed using ImageJ/Fiji win-64 software. Patient data was collected from medical records and questionnaires. ResultsThe vaginal microbiota was Lactobacillus-dominant in most of the samples (n=60), L. iners and L. crispatus being the dominant species. L. gasseri and L. jensenii were found to be more abundant during pregnancy than active labor. L. jensenii abundance correlated with C4 activation during pregnancy but not in labor. Gardnerella vaginalis was associated with C4 activation both during pregnancy and labor. The amount of L. gasseri correlated with factor B activation during pregnancy but not during labor. Atopobium vaginae was more abundant during pregnancy than labor and correlated with C4 activation during labor and with factor B activation during pregnancy. Activation of the alternative pathway factor B was significantly stronger during pregnancy compared to labor. During labor complement activation may be inhibited by the abundant presence of factor H and FHL1. ConclusionsThese results indicate that bacterial composition of the vaginal microbiota could have a role in the local activation and regulation of complement-mediated inflammation during pregnancy. At the time of parturition complement activation appears to be more strictly regulated than during pregnancy.Peer reviewe
Bayesian Group Factor Analysis
We introduce a factor analysis model that summarizes the dependencies between
observed variable groups, instead of dependencies between individual variables
as standard factor analysis does. A group may correspond to one view of the
same set of objects, one of many data sets tied by co-occurrence, or a set of
alternative variables collected from statistics tables to measure one property
of interest. We show that by assuming group-wise sparse factors, active in a
subset of the sets, the variation can be decomposed into factors explaining
relationships between the sets and factors explaining away set-specific
variation. We formulate the assumptions in a Bayesian model which provides the
factors, and apply the model to two data analysis tasks, in neuroimaging and
chemical systems biology.Comment: 9 pages, 5 figure
Early-time Spitzer observations of the type II-Plateau supernova, 2004dj
We present mid-infrared observations with the Spitzer Space Telescope of the
nearby type II-P supernova, SN 2004dj, at epochs of 89 to 129 days. We have
obtained the first mid-IR spectra of any supernova apart from SN 1987A. A
prominent [NiII] 6.64 micron line is observed, from which we deduce that the
mass of stable nickel must be at least 2.2e10(-4) Msun. We also observe the red
wing of the CO-fundamental band. We relate our findings to possible progenitors
and favour an evolved star, most likely a red supergiant, with a probable
initial mass between ~10 and 15 Msun.Comment: ApJ Letters (accepted
Walckenaeria furcillata (Menge, 1869) and Walckenaeria lepida (Kulczynski, 1885) in Finland (Araneae, Linyphiidae)
Walckenaeria furcillata (Menge, 1869) and W. lepida (Kulczynski, 1885) are reported from Finland. Their diagnostics with figures, and distributions and ecological requirements are given. Comparative drawings of genitalia for closely related W. lepida and W. unicornis O. P.-Cambridge, 1861 are presented. The identity of âPseudotigellinusâ subadults figured by Palmgren (1976) is discussed
Ion-Exchanged Waveguides in Glass Doped with PbS Quantum Dots
The lowest-loss (â€1 dB/cm) ion-exchanged waveguides in glass doped with PbS quantum dots are presented. Near-field mode profile and refractive index profile using the refracted near-field technique were measured for these waveguides. We demonstrate that the optical properties of this glass unchanged during the ion-exchange process
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