1,758 research outputs found
Pathogenicity of Septoria aquilina Isolated from Black Hills Bracken
Septoria aquilina, a pathogenic fungus isolated from Pteridium aquilinum growing in the Black Hills was studied from 1991-1995. S. aquilina sprayed at 8,000 conidia/ml on transplanted fronds followed by high humidity caused severe necrosis seven days after inoculation and disease severity increased until fronds died. Severe necrosis also developed from inoculations at 4,000 and 2,000 conidia/ml. Less severe symptoms developed from inoculations at 1,000 conidia/ml. Inoculations at 4,000 conidia/ml not followed by high humidity caused less necrosis than inoculations at the same concentration with high humidity. Inoculations at 4,000, 2,000, and 1,000 conidia/ml on fronds grown from spores caused similar levels of necrosis as inoculations on transplanted fronds. Necrotic epidermal and mesophyll cells were observed in pinnules. In rachises, portions of cortex, endodermis, xylem, and phloem showed abnormal cells or cell destruction. Hyphae were observed infrequently and only in the epidermis and mesophyll of pinnules. S. aquiline is a candidate for field evaluation as a biocontrol agent
The Inter-Mammary Sticky Roll: A Novel Technique for Securing a Doppler Ultrasonic Probe to the Precordium for Venous Air Embolism Detection.
Venous air embolism is a devastating and potentially life-threatening complication that can occur during neurosurgical procedures. We report the development and use of the "inter-mammary sticky roll,"Â a technique to reliably secure a precordial Doppler ultrasonic probe to the chest wall during neurosurgical cases that require lateral decubitus positioning. We have found that this noninvasive technique is safe, and effectively facilitates a constant Doppler signal with no additional risk to the patient
A 10 kpc Scale Seyfert Galaxy Outflow: HST/COS Observations of IRAS F22456-5125
We present analysis of the UV-spectrum of the low-z AGN IRAS-F22456-5125
obtained with the Cosmic Origins Spectrograph on board the Hubble Space
Telescope. The spectrum reveals six main kinematic components, spanning a range
of velocities of up to 800 km s-1, which for the first time are observed in
troughs associated with CII, CIV, NV, SiII, SiIII, SiIV and SIV. We also obtain
data on the OVI troughs, which we compare to those available from an earlier
FUSE epoch. Column densities measured from these ions allow us to derive a
well-constrained photoionization solution for each outflow component. Two of
these kinematic components show troughs associated with transitions from
excited states of SiII\ and CII. The number density inferred from these
troughs, in combination with the deduced ioinization parameter, allows us to
determine the distance to these outflow components from the central source. We
find these components to be at a distance of ~ 10 kpc. The distances and the
number densities derived are consistent with the outflow being part of a
galactic wind.Comment: 52 pages, 15 figures, accepted for publication in ApJ March 25, 201
The AGN Outflow in the HDFS Target QSO J2233-606 from a High-Resolution VLT/UVES Spectrum
We present a detailed analysis of the intrinsic UV absorption in the central
HDFS target QSO J2233-606, based on a high-resolution, high S/N (~25 -- 50)
spectrum obtained with VLT/UVES. This spectrum samples the cluster of intrinsic
absorption systems outflowing from the AGN at radial velocities v ~ -5000 --
-3800 km/s in the key far-UV diagnostic lines - the lithium-like CNO doublets
and H I Lyman series. We fit the absorption troughs using a global model of all
detected lines to solve for the independent velocity-dependent covering factors
of the continuum and emission-line sources and ionic column densities. This
reveals increasing covering factors in components with greater outflow
velocity. Narrow substructure is revealed in the optical depth profiles,
suggesting the relatively broad absorption is comprised of a series of multiple
components. We perform velocity-dependent photoionization modeling, which
allows a full solution to the C, N, and O abundances, as well as the velocity
resolved ionization parameter and total column density. The absorbers are found
to have supersolar abundances, with [C/H] and [O/H] ~0.5 -- 0.9, and [N/H] ~
1.1 -- 1.3, consistent with enhanced nitrogen production expected from
secondary nucleosynthesis processes. Independent fits to each kinematic
component give consistent results for the abundances. The lowest-ionization
material in each of the strong absorbers is modeled with similar ionization
parameters. Components of higher-ionization (indicated by stronger O VI
relative to C IV and N V) are present at velocities just redward of each
low-ionization absorber. We explore the implications of these results for the
kinematic-geometric-ionization structure of the outflow.Comment: 12 pages, 10 figures, emulateapj, accepted for publication in Ap
Antarctic meteorite newsletter. Volume 4: Number 1, February 1981: Antarctic meteorite descriptions, 1976, 1977, 1978, 1979
This issue of the Newsletter is essentially a catalog of all antarctic meteorites in the collections of the Johnson Space Center Curation Facility and the Smithsonian except for 288 pebbles now being classed. It includes listings of all previously distributed data sheets plus a number of new ones for 1979. Indexes of samples include meteorite name/number, classification, and weathering category. Separate indexes list type 3 and 4 chondrites, all irons, all achondrites, and all carbonaceous chondrites
BAL phosphorus abundance and evidence for immense ionic column densities in quasar outflows: VLT X-Shooter observations of quasar SDSS J1512+1119
We present spectroscopic analysis of the broad absorption line outflow in
quasar SDSS J1512+1119. In particular, we focus our attention on a kinematic
component in which we identify PV and SIV/SIV* absorption troughs. The shape of
the unblended phosphorus doublet troughs and the three SIV/SIV* troughs allow
us to obtain reliable column density measurements for these two ions.
Photoionization modelling using these column densities and those of HeI*
constrain the abundance of phosphorus to the range of 0.5-4 times the solar
value. The total column density, ionization parameter and metalicity inferred
from the PV and SIV column densities leads to large optical depth values for
the common transition observed in BAL outflows. We show that the true CIV
optical depth, is about 1000 times greater in the core of the absorption
profile than the value deduced from its apparent optical depth.Comment: Accepted for publication in ApJ on August 26, 2012; 33 pages, 8
figure
Antarctic meteorite descriptions 1976-1977-1978-1979
All previously distributed meteorite data sheets, plus a number of new ones for 1979 chondrites are included. A comprehensive sample index listing meteorite name/number, classification, and weathering category is also included. Separate indexes listing all petrologic type 3 and type 4 chondrites, all irons, all achondrites, and all carbonaceous chondrites in the collection is provided
The ideological divide in confidence in science and participation in medical research
Abstract In the United States, the wide ideological divergence in public confidence in science poses a potentially significant problem for the scientific enterprise. We examine the behavioral consequences of this ideological divide for Americansâ contributions to medical research. Based on a mass survey of American adults, we find that engagement in a wide range of medical research activities is a function of a latent propensity to participate. The propensity is systematically higher among liberals than among conservatives. A substantial part of this ideological divide is due to conservative Americansâ lower confidence in science. These findings raise important issues for the recruitment of subjects for medical studies and the generalizability of results from such studies
Emerging magnetic resonance imaging techniques and analysis methods in amyotrophic lateral sclerosis
Objective markers of disease sensitive to the clinical activity, symptomatic progression, and underlying substrates of neurodegeneration are highly coveted in amyotrophic lateral sclerosis in order to more eloquently stratify the highly heterogeneous phenotype and facilitate the discovery of effective disease modifying treatments for patients. Magnetic resonance imaging (MRI) is a promising, non-invasive biomarker candidate whose acquisition techniques and analysis methods are undergoing constant evolution in the pursuit of parameters which more closely represent biologically-applicable tissue changes. Neurite Orientation Dispersion and Density Imaging (NODDI; a form of diffusion imaging), and quantitative Magnetization Transfer Imaging (qMTi) are two such emerging modalities which have each broadened the understanding of other neurological disorders and have the potential to provide new insights into structural alterations initiated by the disease process in ALS. Furthermore, novel neuroimaging data analysis approaches such as Event-Based Modeling (EBM) may be able to circumvent the requirement for longitudinal scanning as a means to comprehend the dynamic stages of neurodegeneration . Combining these and other innovative imaging protocols with more sophisticated techniques to analyse ever-increasing datasets holds the exciting prospect of transforming understanding of the biological processes and temporal evolution of the ALS syndrome, and can only benefit from multicentre collaboration across the entire ALS research community
Femtosecond spectroscopic study of carminic acidâDNA interactions
Photo-excited carminic acid and carminic acidâDNA complexes in a buffer solution at pH 7 have been examined using a variety of spectroscopy techniques, that are in particular, the femtosecond resolved fluorescence upconversion and transient absorption spectroscopy. The observation of dual fluorescence emission, one peaks at 470 nm and the other at 570 nm, indicates to an excited-state (S1) intramolecular proton transfer (ESIPT). A detailed analysis of the transient absorption measurements of an aqueous carminic-acid solution at pH 7 yielded four lifetimes for the excited-state (S1): 8, 15, 33 and 46 ps. On the other hand, only two lifetimes, 34 and 47 ps, were observed by fluorescence upconversion spectroscopy because of the detection limitation to the long wavelength edge of the carminic-acid spectrum. The four S1 lifetimes were ascribed to the coexistence of respectively two tautomer (normal and tautomer) forms of carminic acid, in the non-dissociated state (CAH) and in the deprotonated state (CAâ). The fluorescence upconversion measurements of carminic acidâDNA complexes exhibited a prolongation of the fluorescence lifetimes. This effect was accepted as evidence for the formation of intercalation complexes between the carminic acid and the DNA. The intercalative binding of the carminic acid to DNA was confirmed by the fluorescence titration experiments resulting to a binding constant of 2 Ă 105 Mâ1 that is typical for anthracyclineâDNA complexes
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