GLORIA

GEOMAR Library Ocean Research Information Access

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    On the stationary distribution of iterative imputations (2014)
    Oxford University Press
    Details
    Publication Date: 2014-02-26
    Description: Iterative imputation, in which variables are imputed one at a time conditional on all the others, is a popular technique that can be convenient and flexible, as it replaces a potentially difficult multivariate modelling problem with relatively simple univariate regressions. In this paper, we begin to characterize the stationary distributions of iterative imputations and their statistical properties, accounting for the conditional models being iteratively estimated from data rather than being prespecified. When the families of conditional models are compatible, we provide sufficient conditions under which the imputation distribution converges in total variation to the posterior distribution of a Bayesian model. When the conditional models are incompatible but valid, we show that the combined imputation estimator is consistent.
    Print ISSN: 0006-3444
    Electronic ISSN: 1464-3510
    Topics: Biology , Mathematics , Medicine
    Published by Oxford University Press
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    facet.materialart.
    Unknown
    Eliminating leukemia stem cells by MNK inhibition [Medical Sciences] (2013)
    National Academy of Sciences
    Details
    Publication Date: 2013-06-19
    Description: Chronic myeloid leukemia responds well to therapy targeting the oncogenic fusion protein BCR-ABL1 in chronic phase, but is resistant to treatment after it progresses to blast crisis (BC). BC is characterized by elevated β-catenin signaling in granulocyte macrophage progenitors (GMPs), which enables this population to function as leukemia stem cells...
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
    Published by National Academy of Sciences
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 3
    facet.materialart.
    Unknown
    Commentary: Physical activity and weight control (2014)
    Oxford University Press
    Details
    Publication Date: 2014-01-11
    Print ISSN: 0300-5771
    Electronic ISSN: 1464-3685
    Topics: Medicine
    Published by Oxford University Press
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 4
    facet.materialart.
    Unknown
    Evidence for the thermal Sunyaev-Zel'dovich effect associated with quasar feedback (2016)
    Oxford University Press
    Details
    Publication Date: 2016-03-24
    Description: Using a radio-quiet subsample of the Sloan Digital Sky Survey spectroscopic quasar catalogue, spanning redshifts 0.5–3.5, we derive the mean millimetre and far-infrared quasar spectral energy distributions (SEDs) via a stacking analysis of Atacama Cosmology Telescope and Herschel -Spectral and Photometric Imaging REceiver data. We constrain the form of the far-infrared emission and find 3–4 evidence for the thermal Sunyaev–Zel'dovich (SZ) effect, characteristic of a hot ionized gas component with thermal energy (6.2 ± 1.7) x 10 60  erg. This amount of thermal energy is greater than expected assuming only hot gas in virial equilibrium with the dark matter haloes of (1–5) x 10 12 h –1 M that these systems are expected to occupy, though the highest quasar mass estimates found in the literature could explain a large fraction of this energy. Our measurements are consistent with quasars depositing up to $(14.5 \pm 3.3)\tau _8^{-1}$  per cent of their radiative energy into their circumgalactic environment if their typical period of quasar activity is 8 x 10 8 yr. For high quasar host masses, ~10 13 h –1 M , this percentage will be reduced. Furthermore, the uncertainty on this percentage is only statistical and additional systematic uncertainties enter at the 40 per cent level. The SEDs are dust dominated in all bands and we consider various models for dust emission. While sufficiently complex dust models can obviate the SZ effect, the SZ interpretation remains favoured at the 3–4 level for most models.
    Print ISSN: 0035-8711
    Electronic ISSN: 1365-2966
    Topics: Physics
    Published by Oxford University Press
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 5
    facet.materialart.
    Unknown
    Foreground-induced biases in CMB polarimeter self-calibration (2016)
    Oxford University Press
    Details
    Publication Date: 2016-02-06
    Description: Precise polarization measurements of the cosmic microwave background (CMB) require accurate knowledge of the instrument orientation relative to the sky frame used to define the cosmological Stokes parameters. Suitable celestial calibration sources that could be used to measure the polarimeter orientation angle are limited, so current experiments commonly ‘self-calibrate.’ The self-calibration method exploits the theoretical fact that the EB and TB cross-spectra of the CMB vanish in the standard cosmological model, so any detected EB and TB signals must be due to systematic errors. However, this assumption neglects the fact that polarized Galactic foregrounds in a given portion of the sky may have non-zero EB and TB cross-spectra. If these foreground signals remain in the observations, then they will bias the self-calibrated telescope polarization angle and produce a spurious B -mode signal. In this paper, we estimate the foreground-induced bias for various instrument configurations and then expand the self-calibration formalism to account for polarized foreground signals. Assuming the EB correlation signal for dust is in the range constrained by angular power spectrum measurements from Planck at 353 GHz (scaled down to 150 GHz), then the bias is negligible for high angular resolution experiments, which have access to CMB-dominated high modes with which to self-calibrate. Low-resolution experiments observing particularly dusty sky patches can have a bias as large as 0 $_{.}^{\circ}$ 5. A miscalibration of this magnitude generates a spurious BB signal corresponding to a tensor-to-scalar ratio of approximately r  ~ 2  x  10 –3 , within the targeted range of planned experiments.
    Print ISSN: 0035-8711
    Electronic ISSN: 1365-2966
    Topics: Physics
    Published by Oxford University Press
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 6
    facet.materialart.
    Unknown
    Migration results in reproductive benefits [Ecology] (2012)
    National Academy of Sciences
    Details
    Publication Date: 2012-09-12
    Description: Little is known of the population dynamics of long-range insect migrants, and it has been suggested that the annual journeys of billions of nonhardy insects to exploit temperate zones during summer represent a sink from which future generations seldom return (the “Pied Piper” effect). We combine data from entomological radars...
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
    Published by National Academy of Sciences
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 7
    facet.materialart.
    Unknown
    Histone deacetylase (HDAC) inhibitors attenuate cardiac hypertrophy by suppressing autophagy [Medical Sciences] (2011)
    National Academy of Sciences
    Details
    Publication Date: 2011-03-09
    Description: Histone deacetylases (HDACs) regulate cardiac plasticity; however, their molecular targets are unknown. As autophagy contributes to pathological cardiac remodeling, we hypothesized that HDAC inhibitors target autophagy. The prototypical HDAC inhibitor (HDACi), trichostatin A (TSA), attenuated both load- and agonist-induced hypertrophic growth and abolished the associated activation of autophagy. Phenylephrine (PE)-triggered hypertrophy and autophagy in cultured cardiomyocytes were each blocked by a panel of structurally distinct HDAC inhibitors. RNAi-mediated knockdown of either Atg5 or Beclin 1, two essential autophagy effectors, was similarly capable of suppressing ligand-induced autophagy and myocyte growth. RNAi experiments uncovered the class I isoforms HDAC1 and HDAC2 as required for the autophagic response. To test the functional requirement of autophagic activation, we studied mice that overexpress Beclin 1 in cardiomyocytes. In these animals with a fourfold amplified autophagic response to TAC, TSA abolished TAC-induced increases in autophagy and blunted load-induced hypertrophy. Finally, we subjected animals with preexisting hypertrophy to HDACi, finding that ventricular mass reverted to near-normal levels and ventricular function normalized completely. Together, these data implicate autophagy as an obligatory element in pathological cardiac remodeling and point to HDAC1/2 as required effectors. Also, these data reveal autophagy as a previously unknown target of HDAC inhibitor therapy.
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
    Published by National Academy of Sciences
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 8
    facet.materialart.
    Unknown
    A cluster of coregulated genes determines TGF-{beta}-induced regulatory T-cell (Treg) dysfunction in NOD mice [Immunology] (2011)
    National Academy of Sciences
    Details
    Publication Date: 2011-05-25
    Description: Foxp3+ regulatory T cells (Tregs) originate in the thymus, but the Treg phenotype can also be induced in peripheral lymphoid organs or in vitro by stimulation of conventional CD4+ T cells with IL-2 and TGF-β. There have been divergent reports on the suppressive capacity of these TGF-Treg cells. We find that TGF-Tregs derived from diabetes-prone NOD mice, although expressing normal Foxp3 levels, are uniquely defective in suppressive activity, whereas TGF-Tregs from control strains (B6g7) or ex vivo Tregs from NOD mice all function normally. Most Treg-typical transcripts were shared by NOD or B6g7 TGF-Tregs, except for a small group of differentially expressed genes, including genes relevant for suppressive activity (Lrrc32, Ctla4, and Cd73). Many of these transcripts form a coregulated cluster in a broader analysis of T-cell differentiation. The defect does not map to idd3 or idd5 regions. Whereas Treg cells from NOD mice are normal in spleen and lymph nodes, the NOD defect is observed in locations that have been tied to pathogenesis of diabetes (small intestine lamina propria and pancreatic lymph node). Thus, a genetic defect uniquely affects a specific Treg subpopulation in NOD mice, in a manner consistent with a role in determining diabetes susceptibility.
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
    Published by National Academy of Sciences
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 9
    facet.materialart.
    Unknown
    Forkhead factor FoxO1 is essential for placental morphogenesis in the developing embryo [Developmental Biology] (2011)
    National Academy of Sciences
    Details
    Publication Date: 2011-09-28
    Description: Forkhead box O1 (FoxO1), a member of the Forkhead box-containing O family of transcription factors, is a key regulator of numerous genes that govern a wide array of cellular functions, including differentiation, homeostasis, and survival. However, the role of FoxO1 in development remains elusive. Here, we describe an essential and previously undefined role for FoxO1 in placental development. We demonstrate that FoxO1-null embryos up to embryonic day 9.0 (E9.0) are indistinguishable, including their morphology, cardiovascular structure, and vascular gene expression, from wild-type (WT) littermates. However, FoxO1-nulls manifested a profoundly swollen/hydropic allantois, which failed to fuse with the chorion, a phenotype that leads to subsequent cardiovascular malformation, progressive apoptotic cell death, and embryonic lethality at E10.5. Quantitative RT-PCR analysis of genes involved in placental development revealed significant attenuation of VCAM1 expression in FoxO1-null embryos. Using immunohistochemical, transcriptional, and chromatin immunoprecipitation assays, we further discovered that FoxO1 is an essential upstream regulator of the VCAM1 gene. Collectively, our findings provide critical molecular insight into a unique FoxO1–VCAM1 axis that governs placental morphogenesis, a process that is essential for subsequent normal cardiovascular development and fetal life.
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
    Published by National Academy of Sciences
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    Global food demand and the sustainable intensification of agriculture [Sustainability Science] (2011)
    National Academy of Sciences
    Details
    Publication Date: 2011-12-14
    Description: Global food demand is increasing rapidly, as are the environmental impacts of agricultural expansion. Here, we project global demand for crop production in 2050 and evaluate the environmental impacts of alternative ways that this demand might be met. We find that per capita demand for crops, when measured as caloric or protein content of all crops combined, has been a similarly increasing function of per capita real income since 1960. This relationship forecasts a 100–110% increase in global crop demand from 2005 to 2050. Quantitative assessments show that the environmental impacts of meeting this demand depend on how global agriculture expands. If current trends of greater agricultural intensification in richer nations and greater land clearing (extensification) in poorer nations were to continue, ∼1 billion ha of land would be cleared globally by 2050, with CO2-C equivalent greenhouse gas emissions reaching ∼3 Gt y−1 and N use ∼250 Mt y−1 by then. In contrast, if 2050 crop demand was met by moderate intensification focused on existing croplands of underyielding nations, adaptation and transfer of high-yielding technologies to these croplands, and global technological improvements, our analyses forecast land clearing of only ∼0.2 billion ha, greenhouse gas emissions of ∼1 Gt y−1, and global N use of ∼225 Mt y−1. Efficient management practices could substantially lower nitrogen use. Attainment of high yields on existing croplands of underyielding nations is of great importance if global crop demand is to be met with minimal environmental impacts.
    Keywords: Sustainability Science
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
    Published by National Academy of Sciences
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...