33 research outputs found

    Obstructive hydrocephalus and intracerebral mass secondary to Epicoccum nigrum

    Get PDF
    Here we report a case of a 14-week-old girl with a history of intrauterine drug exposure and hypoxic ischemic encephalopathy secondary to cardiac arrest requiring prolonged resuscitation at birth presented with irritability and a bulging anterior fontanelle. After neurosurgical resection, pathologic examination showed fungal hyphae, an

    How many human proteoforms are there?

    Get PDF
    Despite decades of accumulated knowledge about proteins and their post-translational modifications (PTMs), numerous questions remain regarding their molecular composition and biological function. One of the most fundamental queries is the extent to which the combinations of DNA-, RNA- and PTM-level variations explode the complexity of the human proteome. Here, we outline what we know from current databases and measurement strategies including mass spectrometry-based proteomics. In doing so, we examine prevailing notions about the number of modifications displayed on human proteins and how they combine to generate the protein diversity underlying health and disease. We frame central issues regarding determination of protein-level variation and PTMs, including some paradoxes present in the field today. We use this framework to assess existing data and to ask the question, "How many distinct primary structures of proteins (proteoforms) are created from the 20,300 human genes?" We also explore prospects for improving measurements to better regularize protein-level biology and efficiently associate PTMs to function and phenotype

    Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

    Get PDF
    Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

    Observation of gravitational waves from the coalescence of a 2.5−4.5 M⊙ compact object and a neutron star

    Get PDF

    Ultralight vector dark matter search using data from the KAGRA O3GK run

    Get PDF
    Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

    Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

    Get PDF
    Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

    Spatial variability in the coupling of organic carbon, nutrients, and phytoplankton pigments in surface waters and sediments of the Mississippi River plume

    No full text
    River-dominated coastal areas are typically sites of active biogeochemical cycling, with productivity enhanced by terrestrial inputs of nutrients and organic matter. To examine the spatial variability and relationship between river discharge, phytoplankton, and organic carbon distributions, we analyzed surface water and sediment from the Louisiana shelf adjacent to the Mississippi River. Samples were collected during April and October 2000 to capture high and low river discharge, and were analyzed for dissolved and particulate organic carbon (DOC and POC), nutrients, and phytoplankton pigments. Pigments, determined by high performance liquid chromatography (HPLC), were also analyzed from sediment to evaluate marine carbon inputs to the seafloor. DOC in surface waters was generally within 200-300 mu M, ranging up to 399 mu M. Chlorophyll a ranged from below the limits of detection (BLD) up to 31 nM in surface waters, with higher values located further from the river mouth during high flow. Although community diversity increased during low discharge, diatoms dominated the phytoplankton population (50-80% of the community throughout the study) and consequently made more important contributions than other species to both the DOC and POC pools. Chlorophyll and degradation products (indicative of zooplankton grazing) observed in surface sediment indicated a transfer of autochthonous carbon from the highly productive photic zone to the sediment, coupling phytoplankton-derived POC in surface waters with organic carbon deposition in surface sediment. Cross-shelf changes in chlorophyll indicated a westward transport of phytoplankton that was directly and indirectly linked with river discharge and pigment decay dynamics. (c) 2006 Elsevier Ltd. All rights reserved

    Encouraging Science Communication through Deliberative Pedagogy: A Study of a Gene Editing Deliberation in a Nonmajors Biology Course

    No full text
    Deliberative pedagogy encourages productive science communication and learning through engagement and discussion of socio-scientific issues (SSI). This article examines a two-day deliberation module on gene editing that took place in an introductory nonmajors biology course, furthering research on integrating deliberative discussion into the biology classroom. The results demonstrate the benefits of a single, episodic deliberation in the classroom, which can positively encourage active discussion and critical awareness of connections between biology and real-world issues, thus contributing to the development of scientific citizenship. Additionally, the findings show that gene editing is an apt SSI topic for the deliberative process because it encourages productive communication practices of scientific citizenship, including discussion, perspective taking, questioning, and consideration of different types of evidence when coming to a decision

    MIT Sloan School of Management THE WALKDOWN TO BEATABLE ANALYST FORECASTS: THE ROLES OF EQUITY ISSUANCE AND INSIDER TRADING INCENTIVES The Walkdown to Beatable Analyst Forecasts: The Roles of Equity Issuance and Insider Trading Incentives We gratefully ac

    No full text
    Abstract Security regulators and the business press have alleged that firms play an "earnings-guidance game" where analysts make optimistic forecasts at the start of the year and then 'walk down' their estimates to a level the firm can beat by the end of the year. In a comprehensive sample of I/B/E/S individual analysts' forecasts of annual earnings from 1983-1998, we find strong support for the claim in the post-1992 period. We examine whether the 'walk down' to beatable targets is associated with managers' incentives to sell stock after earnings announcements on the firm's behalf (via new equity issuance) or from their personal accounts (insider trades). Consistent with these hypotheses, we find that the 'walk down' to beatable targets is most pronounced in firms that are either net issuers of equity or in firms where managers are net sellers of stock after an earnings announcement. These findings provide new insights on how capital market incentives affect communications between managers and analysts
    corecore