Study of antiproton annihilation in silicon with a hybrid pixel detector using the TimePix3 readout

The main goal of the AEgIS experiments is to measure the gravitational force for anti-hydrogen, testing Einstein's weak equivalence principle, which states that all bodies falls with the same acceleration, independently from their mass and composition. The measurement will be done using an anti-hydrogen beam sent trough a classical moire deflectometer. To measure the deflection of the beam from a straight path a position sensitive silicon detector followed by an emulsion detector and a scintillating fiber time-of-flight detector will be used. We present here a study performed using a novel hybrid pixel detector, employing the Timepix3 readout chip to tag and spatially resolve antiproton annihilations in silicon. In autumn 2014 we performed a test-experiment on a secondary beam line to the AEgIS experiment, where a pulsed beam of anti-protons of energy 5.3 MeV was delivered from the Antiproton Decelerator of CERN accelerator complex. Taking advantage of the high spatial resolution, ToA capabilities and extended energy range of the Timepix3, this study investigates unique features of antiproton annihilation events in silicon. We are for the first time able to set clear criteria to characterize an antiproton annihilation using a silicon detector

Informed stakeholder support for managing invasive <i>Hydrilla verticillata</i> linked to wildlife deaths in a Southeastern reservoir

<p>Fouts KL, Poudyal, NC, Moore R, Herrin J, Wilde, SB. 2017. Informed stakeholder support for managing invasive <i>Hydrilla verticillata</i> linked to wildlife deaths in a Southeastern reservoir. Lake Reserve Manage. 00:1–10.</p> <p>Public opinion surveys prior to implementing management actions provide managing agencies with a detailed understanding of stakeholders' attitudes and help inform the general public on the complexity of potential management actions. Like many other Southeastern U.S. reservoirs, J. Strom Thurmond (JST), on the border of Georgia and South Carolina, has been infested with nonnative hydrilla (<i>Hydrilla verticillata</i>). Avian Vacuolar Myelinopathy (AVM), a fatal wildlife disease linked to a neurotoxic cyanobacterial species growing on hydrilla, has been documented on this 28,733-ha reservoir since 1998, when the hydrilla acreage first exceeded 350 ha. As of 2016, 90 bald eagle (<i>Haliaeetus leucocephalus</i>) mortalities and hundreds of waterfowl deaths have been attributed to AVM disease on JST. To assess and compare the diverse stakeholders' attitudes toward aquatic vegetation, knowledge of AVM, and support for management actions to remove hydrilla, a mail survey was conducted targeting various JST user groups (anglers, boaters, campers, waterfowl hunters, and shoreline property owners). Generally, respondents were overwhelmingly in favor of reducing hydrilla density on JST, but shoreline permit holders (homeowners) were significantly more supportive of hydrilla management than boaters. Similarly, all user groups supported management actions to remove aquatic vegetation, including stocking triploid sterile grass carp (<i>Ctenopharyngodon idella</i>). Support for removing hydrilla was found to be significantly higher among users knowledgeable of AVM, suggesting that outreach activities educating the public on the effects and prevention of the disease would help enhance stakeholder support for hydrilla removal and management in public reservoirs.</p

Managing Gastrointestinal Symptoms Resulting from Treatment with Trofinetide for Rett Syndrome: Caregiver and Nurse Perspectives

 Article full text The article associated with this page has been accepted for online publication and is in the final stages of production. The link to the full text will be made available on this page in the next few days.  The above audio abstract represents the opinions of the authors. For a full list of declarations, including funding and author disclosure statements, and copyright information, please see the full text online. (see “read the peer-reviewed publication” opposite). </p

Solution Structure and Molecular Determinants of Hemoglobin Binding of the First NEAT Domain of IsdB in Staphylococcus aureus

The human pathogen Staphylococcus aureus acquires heme iron from hemoglobin (Hb) via the action of a series of iron-regulated surface determinant (Isd) proteins. The cell wall anchored IsdB protein is recognized as the predominant Hb receptor, and is comprised of two NEAr transporter (NEAT) domains that act in concert to bind, extract, and transfer heme from Hb to downstream Isd proteins. Structural details of the NEAT 2 domain of IsdB have been investigated, but the molecular coordination between NEAT 2 and NEAT 1 to extract heme from hemoglobin has yet to be characterized. To obtain a more complete understanding of IsdB structure and function, we have solved the 3D solution structure of the NEAT 1 domain of IsdB (IsdB^N1) spanning residues 125–272 of the full-length protein by NMR. The structure reveals a canonical NEAT domain fold and has particular structural similarity to the NEAT 1 and NEAT 2 domains of IsdH, which also interact with Hb. IsdB^N1 is also comprised of a short N-terminal helix, which has not been previously observed in other NEAT domain structures. Interestingly, the Hb binding region (loop 2 of IsdB^N1) is disordered in solution. Analysis of Hb binding demonstrates that IsdB^N1 can bind metHb weakly and the affinity of this interaction is further increased by the presence of IsdB linker domain. IsdB^N1 loop 2 variants reveal that phenylalanine 164 (F164) of IsdB is necessary for Hb binding and rapid heme transfer from metHb to IsdB. Together, these findings provide a structural role for IsdB^N1 in enhancing the rate of extraction of metHb heme by the IsdB NEAT 2 domain