Mocarts: a lightweight radiation transport simulator for easy handling of complex sensing geometries

In functional neuroimaging (fNIRS), elaborated sensing geometries pairing multiple light sources and detectors arranged over the tissue surface are needed. A variety of software tools for probing forward models of radiation transport in tissue exist, but their handling of sensing geometries and specification of complex tissue architectures is, most times, cumbersome. In this work, we introduce a lightweight simulator, Monte Carlo Radiation Transport Simulator (MOCARTS) that attends these demands for simplifying specification of tissue architectures and complex sensing geometries. An object-oriented architecture facilitates such goal. The simulator core is evolved from the Monte Carlo Multi-Layer (mcml) tool but extended to support multi-channel simulations. Verification against mcml yields negligible error (RMSE~4-10e-9) over a photon trajectory. Full simulations show concurrent validity of the proposed tool. Finally, the ability of the new software to simulate multi-channel sensing geometries and to define biological tissue models in an intuitive nested-hierarchy way are exemplified

Walking to Olympus: An EVA Chronology

Spacewalkers enjoy a view of Earth once reserved for Apollo, Zeus, and other denizens of Mt. Olympus. During humanity's first extravehicular activity (EVA), Alexei Leonov floated above Gibraltar, the rock ancient seafarers saw as the gateway to the great unknown Atlantic. The symbolism was clear, Leonov stepped past a new Gibraltar when he stepped into space. More than 32 years and 154 EVAs later, Jerry Linenger conducted an EVA with Vladimir Tsibliyev as part of International Space Station Phase 1. They floated together above Gibraltar. Today the symbolism has new meaning: humanity is starting to think of stepping out of Earth orbit, space travel's new Gibraltar, and perhaps obtaining a new olympian view, a close-up look at Olympus Mons on Mars. Walking to Olympus: An EVA Chronology chronicles the 154 EVAs conducted from March 1965 to April 1997. It is intended to make clear the crucial role played by EVA in the history of spaceflight, as well as to chronicle the large body of EVA "lessons learned." Russia and the U.S. define EVA differently. Russian cosmonauts are said to perform EVA any time they are in vacuum in a space suit. A U.S. astronaut must have at least his head outside his spacecraft before he is said to perform an EVA. The difference is based in differing spacecraft design philoso- phies. Russian and Soviet spacecraft have always had a specialized airlock through which the EVA cosmonaut egressed, leaving the main habitable volume of the spacecraft pressurized. The U.S. Gemini and Apollo vehicles, on the other hand, depressurized their entire habitable volume for egress. In this document, we apply the Russian definition to Russian EVAS, and the U.S. definition to U.S. EVAS. Thus, for example, Gemini 4 Command Pilot James McDivitt does not share the honor of being first American spacewalker with Ed White, even though he was suited and in vacuum when White stepped out into space. Non-EVA spaceflights are listed in the chronology to provide context and to display the large num- ber of flights in which EVA played a role. This approach also makes apparent significant EVA gaps, for example, the U.S. gap between 1985 and 1991 following the Challenger accident. This NASA History Monograph is an edited extract from an extensive EVA Chronology and Reference Book being produced by the EVA Project Office, NASA Johnson Space Center, Houston, Texas. The larger work will be published as part of the NASA Formal Series in 1998. The authors gratefully acknowledge the assistance rendered by Max Ary, Ashot Bakunts, Gert-Jan Bartelds, Frank Cepollina, Andrew Chaikin, Phillip Clark, Richard Fullerton, Steven Glenn, Linda Godwin, Jennifer Green, Greg Harris, Clifford Hess, Jeffrey Hoffman, David Homan, Steven Hopkins, Nicholas Johnson, Eric Jones, Neville Kidger, Joseph Kosmo, Alexei Lebedev, Mark Lee, James LeBlanc, Dmitri Leshchenskii, Jerry Linenger, Igor Lissov, James McBarron, Clay McCullough, Joseph McMann, Story Musgrave, Dennis Newkirk, James Oberg, Joel Powell, Lee Saegesser, Andy Salmon, Glen Swanson, Joseph Tatarewicz, Kathy Thornton, Chris Vandenberg, Charles Vick, Bert Vis, David Woods, Mike Wright, John Young, and Keith Zimmerman. Special thanks to Laurie Buchanan, John Charles, Janet Kovacevich, Joseph Loftus, Sue McDonald, Martha Munies, Colleen Rapp, and Jerry Ross. Any errors remain the responsibility of the authors

Mouse aorta-derived mesenchymal progenitor cells contribute to and enhance the immune response of macrophage cells under inflammatory conditions

Abstract Introduction: Mesenchymal progenitor cells interact with immune cells and modulate inflammatory responses. The cellular characteristics required for this modulation are under fervent investigation. Upon interaction with macrophage cells, they can contribute to or suppress an inflammatory response. Current studies have focused on mesenchymal progenitors derived from bone marrow, adipose, and placenta. However, the arterial wall contains many mesenchymal progenitor cells, which during vascular disease progression have the potential to interact with macrophage cells. To examine the consequence of vascular-tissue progenitor cell-macrophage cell interactions in an inflammatory environment, we used a recently established mesenchymal progenitor cell line derived from the mouse aorta. Methods: Mouse bone marrow-derived macrophage (MΦ) cells and mouse aorta-derived mesenchymal progenitor (mAo) cells were cultured alone or co-cultured directly and indirectly. Cells were treated with oxidized low-density lipoprotein (ox-LDL) or exposed to the inflammatory mediators lipopolysaccharide (LPS) and interferon-gamma (IFNγ) or both. A Toll-like receptor-4 (TLR4)-deficient macrophage cell line was used to determine the role of the mAo cells. To monitor inflammation, nitric oxide (NO), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNFα) secretions were measured. Results: Mesenchymal progenitor cells isolated from aorta and cloned by high proliferative capacity (mAo) can differentiate into multiple mesenchymal lineages and are positive for several commonly used mouse mesenchymal stem cell markers (that is, CD29, CD44, CD105, CD106, and Sca-1) but are negative for CD73 and ecto-5′-nucleotidase. In co-culture with MΦ cells, they increase MΦ oxidized-LDL uptake by 52.2%. In an inflammatory environment, they synergistically and additively contribute to local production of both NO and IL-6. After exposure to ox-LDL, the inflammatory response of MΦ cells to LPS and LPS/IFNγ is muted. However, when lipid-laden MΦ cells are co-cultured with mAo cell progenitors, the muted response is recovered and the contribution by the mAo cell progenitor is dependent upon cell contact. Conclusions: The resident mesenchymal progenitor cell is a potential contributor to vascular inflammation when in contact with inflamed and lipid-laden MΦ cells. This interaction represents an additional target in vascular disease treatment. The potential for resident cells to contribute to the loca

Near-field distribution and propagation of scattering resonances in Vogel spiral arrays of dielectric nanopillars

In this work, we employ scanning near-field optical microscopy, full-vector finite difference time domain numerical simulations and fractional Fourier transformation to investigate the near-field and propagation behavior of the electromagnetic energy scattered at 1.56µm by dielectric arrays of silicon nitride nanopillars with chiral 1-Vogel spiral geometry. In particular, we experimentally study the spatial evolution of scattered radiation and demonstrate near-field coupling between adjacent nanopillars along the parastichies arms. Moreover, by measuring the spatial distribution of the scattered radiation at different heights from the array plane, we demonstrate a characteristic rotation of the scattered field pattern consistent with net transfer of orbital angular momentum in the Fresnel zone, within a few micrometers from the plane of the array. Our experimental results agree with the simulations we performed and may be of interest to nanophotonics applications

Coexistence but Independent Biosynthesis of Catechyl and Guaiacyl/Syringyl Lignin Polymers in Seed Coats

Lignins are phenylpropanoid polymers, derived from monolignols, commonly found in terrestrial plant secondary cell walls. We recently reported evidence of an unanticipated catechyl lignin homopolymer (C lignin) derived solely from caffeyl alcohol in the seed coats of several monocot and dicot plants. We previously identified plant seeds that possessed either C lignin or traditional guaiacyl/syringyl (G/S) lignins, but not both. Here, we identified several dicot plants (Euphorbiaceae and Cleomaceae) that produce C lignin together with traditional G/S lignins in their seed coats. Solution-state NMR analyses, along with an in vitro lignin polymerization study, determined that there is, however, no copolymerization detectable (i.e., that the synthesis and polymerization of caffeyl alcohol and conventional monolignols in vivo is spatially and/or temporally separated). In particular, the deposition of G and C lignins in Cleome hassleriana seed coats is developmentally regulated during seed maturation; C lignin appears successively after G lignin within the same testa layers, concurrently with apparent loss of the functionality of O-methyltransferases, which are key enzymes for the conversion of C to G lignin precursors. This study exemplifies the flexible biosynthesis of different types of lignin polymers in plants dictated by substantial, but poorly understood, control of monomer supply by the cells

Incommensurate spin density wave in metallic V_(2-y)O_3

We show by neutron diffraction that metallic V_(2-y)O_3 develops a spin density wave below T_N≊9 K with incommensurate wave vector q≊1.7c* and an ordered moment of 0.15μ_B. The weak ordering phenomenon is accompanied by strong, nonresonant spin fluctuations with a velocity c = 67(4) meV Å. The spin correlations of the metal are very different from those of the insulator and place V_(2-y)O_3 in a distinct class of Mott-Hubbard systems where the wave vector for magnetic order in the metal is far from a high symmetry commensurate reciprocal lattice point

De novo meningitis caused by Propionibacterium acnes in a patient with metastatic melanoma

Propionibacterium acnes is a known cause of postneurosurgical meningitis; however, it is rarely implicated in de novo meningitis. Herein we report a case of a 49-year-old male with de novo meningitis caused by P. acnes with metastatic melanoma as the only identified risk factor for his infection

Human Illnesses and Animal Deaths Associated with Freshwater Harmful Algal Blooms-Kansas

Citation: Trevino-Garrison, I., DeMent, J., Ahmed, F. S., Haines-Lieber, P., Langer, T., Menager, H., . . . Carney, E. (2015). Human Illnesses and Animal Deaths Associated with Freshwater Harmful Algal Blooms-Kansas. Toxins, 7(2), 353-366. doi:10.3390/toxins7020353Freshwater harmful algal bloom (FHAB) toxins can cause morbidity and mortality in both humans and animals, and the incidence of FHABs in the United States and Kansas has increased. In 2010, the Kansas Department of Health and Environment (KDHE) developed a FHAB policy and response plan. We describe the epidemiology of FHAB-associated morbidity and mortality in humans and animals in Kansas. Healthcare providers and veterinarians voluntarily reported FHAB-associated cases to KDHE. An investigation was initiated for each report to determine the source of exposure and to initiate public health mitigation actions. There were 38 water bodies with a confirmed FHAB in 2011. There were 34 reports of human and animal FHAB-associated health events in 2011, which included five dog deaths and hospitalization of two human case patients. Five confirmed human illnesses, two dog illnesses and five dog deaths were associated with one lake. Four human and seven dog cases were exposed to the lake after a public health alert was issued. Public health officials and FHAB partners must ensure continued awareness of the risks to the public, educate healthcare providers and veterinarians on FHAB-related health events and encourage timely reporting to public health authorities

The AMS-02 RICH Imager Prototype - In-Beam Tests with 20 GeV/c per Nucleon Ions -

A prototype of the AMS Cherenkov imager (RICH) has been tested at CERN by means of a low intensity 20 GeV/c per nucleon ion beam obtained by fragmentation of a primary beam of Pb ions. Data have been collected with a single beam setting, over the range of nuclear charges 2<Z<~45 in various beam conditions and using different radiators. The charge Z and velocity beta resolutions have been measured.Comment: 4 pages, contribution to the ICRC 200

The Ring Imaging Cherenkov detector (RICH) of the AMS experiment

The Alpha Magnetic Spectrometer (AMS) experiment to be installed on the International Space Station (ISS) will be equipped with a proximity focusing Ring Imaging Cherenkov (RICH) detector for measuring the electric charge and velocity of the charged cosmic particles. A RICH prototype consisting of 96 photomultiplier units, including a piece of the conical reflector, was built and its performance evaluated with ion beam data. Preliminary results of the in-beam tests performed with ion fragments resulting from collisions of a 158 GeV/c/nuc primary beam of Indium ions (CERN SPS) on a Pb target are reported. The collected data included tests to the final front-end electronics and to different aerogel radiators. Cherenkov rings for a large range of charged nuclei and with reflected photons were observed. The data analysis confirms the design goals. Charge separation up to Fe and velocity resolution of the order of 0.1% for singly charged particles are obtained.Comment: 29th International Conference on Cosmic Rays (Pune, India