757 research outputs found
Amanita drummondii and A. quenda (Basidiomycota), two new species from Western Australia, and an expanded description of A. walpolei
Three species of Amanita Pers. are documented from Western Australia. Amanita drummondii E.M.Davison is described from the south-west region; it appears to be widespread but infrequent. Amanita quenda E.M.Davison is described from the Perth Metropolitan area. Amanita walpolei O.K.Mill. is redescribed to include additional collections, drawing attention to the presence of clamp connections in all tissues. A BLASTn search has shown that there are no exact matches of the nuclear ribosomal internal transcribed spacer (ITS) region of each species with those in GenBank
Neotypification and redescription of Amanita preissii (Basidiomycota), and reconsideration of the status of A. griseibrunnea
Amanita preissii (Fr.) Sacc. is redescribed. Re-examination of collections of
A. griseibrunnea O.K.Mill. show that they do not differ significantly from A. preissii and the two
species are combined. This species is common in the Perth IBRA subregion. Sequence data from the
nuclear ribosomal internal transcribed spacer (ITS) region, 28S nuclear ribosomal large subunit rRNA
(28S) region, RNA polymerase II (RPB2) region, β-tubulin region and translation elongation factor
1-α (EF1-α) region have been deposited in GenBank
Perspective: The first ten years of broadband chirped pulse Fourier transform microwave spectroscopy
Since its invention in 2006, the broadband chirped pulse Fourier transform spectrometer has transformed the field of microwave spectroscopy. The technique enables the collection of a ≥10 GHz bandwidth spectrum in a single shot of the spectrometer, which allows broadband, high-resolution microwave spectra to be acquired several orders of magnitude faster than what was previously possible. We discuss the advantages and challenges associated with the technique and look back on the first ten years of chirped pulse Fourier transform spectroscopy. In addition to enabling faster-than-ever structure determination of increasingly complex species, the technique has given rise to an assortment of entirely new classes of experiments, ranging from chiral sensing by three-wave mixing to microwave detection of multichannel reaction kinetics. However, this is only the beginning. Future generations of microwave experiments will make increasingly creative use of frequency-agile pulse sequences for the coherent manipulation and interrogation of molecular dynamics.United States. Dept. of Energy. Office of Basic Energy Sciences. Chemical Sciences, Geosciences, & Biosciences Division (Grant DE-FG0287ER13671)National Science Foundation (U.S.) (Grant CHE-1361865)Petroleum Research Fund (Grant 50650-ND6
Alignment and preliminary outcomes of an ELT-size instrument to a very large telescope: LINC-NIRVANA at LBT
LINC-NIRVANA (LN) is a high resolution, near infrared imager that uses a
multiple field-of-view, layer-oriented, multi-conjugate AO system, consisting
of four multi-pyramid wavefront sensors (two for each arm of the Large
Binocular Telescope, each conjugated to a different altitude). The system
employs up to 40 star probes, looking at up to 20 natural guide stars
simultaneously. Its final goal is to perform Fizeau interferometric imaging,
thereby achieving ELT-like spatial resolution (22.8 m baseline resolution). For
this reason, LN is also equipped with a fringe tracker, a beam combiner and a
NIR science camera, for a total of more than 250 optical components and an
overall size of approximately 6x4x4.5 meters. This paper describes the
tradeoffs evaluated in order to achieve the alignment of the system to the
telescope. We note that LN is comparable in size to planned ELT
instrumentation. The impact of such alignment strategies will be compared and
the selected procedure, where the LBT telescope is, in fact, aligned to the
instrument, will be described. Furthermore, results coming from early
night-time commissioning of the system will be presented.Comment: 8 pages, 6 pages, AO4ELT5 Proceedings, 201
Furthering Precision in Sentinel Node Navigational Surgery for Oral Cancer: a Novel Triple Targeting System
To describe an innovative sentinel lymph node (SLN) guidance approach using a radionuclide tracer, 3D augmented reality-guided imaging, and near infrared (NIR) fluorescence over-lay imaging with hand-held probes to optimize accuracy, efficiency, and precise navigation for sentinel node (SN) localization in head and neck cancer. In a cT1N0M0 squamous cell carcinoma of the tongue, pre-operative radionuclide lymphoscintigraphy was performed with a sentinel node-specific radiolabeled tracer. Intraoperatively, a 3D hand-held augmented reality (AR) scanning SPECT probe assessed concordance of the SN with pre-operative SPECT-CT images. The real-time optical video was linked to the SPECT-CT images for added precision. Final guidance to the SN was performed using ICG fluorescence imaging. Dynamic and SPECT-CT showed bilateral lymphatic drainage from the tumor. The 3D hand-held AR SPECT probe SN localization was concordant with pre-operative imaging. The optical video successfully demonstrated the lymphatic drainage in real-time through a unique overlay fluorescence image. The ICG localized to the same nodes identified by both the SPECT-CT and hand-held SPECT images. The use of dual radiation and fluorescence tracers improved SN detection, especially for SN close to the injection site. The hand-held probes allowed the surgeon to dissect continuously, without needing to change tools. The combination of augmented reality, nuclear medicine, and over-lay fluorescence imaging allowed greater accuracy for matching the preoperative imaging with intraoperative identification and precisely guiding the dissection. This method uniquely permitted the surgeon to efficiently dissect the SN with accurate visualization and optimal precision
A Data Driven Approach to Audiovisual Speech Mapping
The concept of using visual information as part of audio speech processing has been of significant recent interest. This paper presents a data driven approach that considers estimating audio speech acoustics using only temporal visual information without considering linguistic features such as phonemes and visemes. Audio (log filterbank) and visual (2D-DCT) features are extracted, and various configurations of MLP and datasets are used to identify optimal results, showing that given a sequence of prior visual frames an equivalent reasonably accurate audio frame estimation can be mapped
Adaptive Optics Imaging of QSOs with Double-Peaked Narrow Lines: Are they Dual AGNs?
Active galaxies hosting two accreting and merging super-massive black holes
(SMBHs) -- dual Active Galactic Nuclei (AGN) -- are predicted by many current
and popular models of black hole-galaxy co-evolution. We present here the
results of a program that has identified a set of probable dual AGN candidates
based on near Infra-red (NIR) Laser Guide-Star Adaptive Optics (LGS AO) imaging
with the Keck II telescope. These candidates are selected from a complete
sample of radio-quiet Quasi-stellar Objects (QSOs) drawn from the Sloan Digital
Sky Survey (SDSS), which show double-peaked narrow AGN emission lines. Of the
twelve AGNs imaged, we find six with double galaxy structure, of which four are
in galaxy mergers. We measure the ionization of the two velocity components in
the narrow AGN lines to test the hypothesis that both velocity components come
from an active nucleus. The combination of a well-defined parent sample and
high-quality imaging allows us to place constraints on the fraction of SDSS
QSOs that host dual accreting black holes separated on kiloparsec (kpc) scales:
~0.3%-0.65%. We derive from this fraction the time spent in a QSO phase during
a typical merger and find a value that is much lower than estimates that arise
from QSO space densities and galaxy merger statistics. We discuss possible
reasons for this difference. Finally, we compare the SMBH mass distributions of
single and dual AGN and find little difference between the two within the
limited statistics of our program, hinting that most SMBH growth happens in the
later stages of a merger process.Comment: 9 pages, 4 figures, 1 table; accepted to the Astrophysical Journa
Correlation Between the Deuteron Characteristics and the Low-energy Triplet np Scattering Parameters
The correlation relationship between the deuteron asymptotic normalization
constant, , and the triplet np scattering length, , is
investigated. It is found that 99.7% of the asymptotic constant is
determined by the scattering length . It is shown that the linear
correlation relationship between the quantities and
provides a good test of correctness of various models of nucleon-nucleon
interaction. It is revealed that, for the normalization constant and
for the root-mean-square deuteron radius , the results obtained with the
experimental value recommended at present for the triplet scattering length
are exaggerated with respect to their experimental counterparts. By
using the latest experimental phase shifts of Arndt et al., we obtain, for the
low-energy scattering parameters (, , ) and for the
deuteron characteristics (, ), results that comply well with
experimental data.Comment: 19 pages, 1 figure, To be published in Physics of Atomic Nucle
Audiovisual annotation procedure for multi-view field recordings
Audio and video parts of an audiovisual document interact to produce an audiovisual, or multi-modal, perception. Yet, automatic analysis on these documents are usually based on separate audio and video annotations. Regarding the audiovisual content, these annotations could be incomplete, or not relevant. Besides, the expanding possibilities of creating audiovisual documents lead to consider different kinds of contents, including videos filmed in uncontrolled conditions (i.e. fields recordings), or scenes filmed from different points of view (multi-view). In this paper we propose an original procedure to produce manual annotations in different contexts, including multi-modal and multi-view documents. This procedure, based on using both audio and video annotations, ensures consistency considering audio or video only, and provides additionally audiovisual information at a richer level. Finally, different applications are made possible when considering such annotated data. In particular, we present an example application in a network of recordings in which our annotations allow multi-source retrieval using mono or multi-modal queries
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