564 research outputs found
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Four new species from the diatom (Bacillariophyceae) genus Adlafia Moser, Lange-Bertalot & Metzeltin from waterbodies of Vietnam
Four species of the diatom genus were found from waterbodies of Vietnam and described as new to science. Their formal descriptions are presented herein and they are illustrated by light and scanning electron micrographs. These new species are: Glushch., Kulik. Kociolek, , Glushch., Kulik. Kociolek, , Glushch., Kulik. Kociolek, and Glushch., Kulik. Kociolek, These species are then compared to other similar taxa. Our new findings add to the number of species in this interesting genus and contribute to our understanding of the unique diatom flora found in Vietnam. Keywords: , diatoms, morphology, new species, Southeast Asia, Vietnam</p
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Two new species of Navicula (Bacillariophyta) from Southeast Asia
We present light and scanning electron microscopical observations on two new species of Navicula Bory sensu stricto from Southeast Asia. Navicula winoniformis Chudaev, Glushchenko, Kulikovskiy & Kociolek, sp. nov. differs from taxa with similar outline and size by the combination of simple drop-like external raphe endings deflected to the primary valve side, presence of well-developed external longitudinal grooves and relatively low lineolae density. Navicula sparsilineolata Chudaev, Glushchenko, Kulikovskiy & Kociolek, sp. nov. can be discriminated from the taxa of similar valve shape and size by consistently lower lineolae density, and from the majority of them also by the structure of external proximal raphe endings with small projections in proximal parts and larger triangular insertions in distal parts. Some remarks on Navicula species diversity and its distribution in the Southeast Asia are given.
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Mass hierarchy discrimination with atmospheric neutrinos in large volume ice/water Cherenkov detectors
Large mass ice/water Cherenkov experiments, optimized to detect low energy
(1-20 GeV) atmospheric neutrinos, have the potential to discriminate between
normal and inverted neutrino mass hierarchies. The sensitivity depends on
several model and detector parameters, such as the neutrino flux profile and
normalization, the Earth density profile, the oscillation parameter
uncertainties, and the detector effective mass and resolution. A proper
evaluation of the mass hierarchy discrimination power requires a robust
statistical approach. In this work, the Toy Monte Carlo, based on an extended
unbinned likelihood ratio test statistic, was used. The effect of each model
and detector parameter, as well as the required detector exposure, was then
studied. While uncertainties on the Earth density and atmospheric neutrino flux
profiles were found to have a minor impact on the mass hierarchy
discrimination, the flux normalization, as well as some of the oscillation
parameter (\Delta m^2_{31}, \theta_{13}, \theta_{23}, and \delta_{CP})
uncertainties and correlations resulted critical. Finally, the minimum required
detector exposure, the optimization of the low energy threshold, and the
detector resolutions were also investigated.Comment: 23 pages, 16 figure
A case report of successful endovascular treatment of "sentinel bleeding" in patient with adverse anatomy
Surgical treatment of pancreatic cancer, has a high risk of postoperative complications (up to 30-70%) due to its difficulty, one of such undesirable outcomes is bleeding (up to 10% of all post PDE complication. Since 1991, a non-fatal gastrointestinal bleeding or bleeding through drainage that follows PDE, is called - “sentinel bleeding”; and it is a predictor of further massive fatal bleedin
A novel tri-unsaturated highly branched isoprenoid (HBI) alkene from the marine diatom Navicula salinicola
A novel tri-unsaturated C25 highly branched isoprenoid (HBI) alkene has been identified in a laboratory culture of the diatom Navicula salinicola and its structure determined using a combination of NMR spectroscopy and gas chromatography–mass spectrometry (GC–MS). This represents the first report of a C25 HBI in a marine diatom from the Navicula genus, although a different tri-unsaturated C25 HBI has been reported previously in the freshwater species N. sclesvicensis and unspecified HBIs have been identified in the brackish N. phyllepta. The newly characterised HBI contains a relatively unusual conjugated diene sub-unit, a structural feature only previously reported in some HBIs biosynthesised by a further marine diatom, Haslea ostrearia
Kulikovskiyia gen. nov. (Bacillariophyceae) from the lateritic rock pools of the Western Ghats, India and from Hainan Province, China
A new triundulate naviculoid diatom genus is described from the Western Ghats of Peninsular India and Hainan Province, China. The new taxon, Kulikovskiyia gen. nov. has robust conical spines along its margin and at the apices and the external valve face has longitudinally‐oriented siliceous slat system extending the length of the valve. The external distal raphe ends bifurcate and terminates on the valve face. There appear to be superficial similarities between this Asian genus and species and Playaensis, a genus comprised of two species found only in the western USA. The systematic position of Kulikovskiyia is discussed, and other than noting its similarities to other biraphid naviculoid diatoms due to symmetry features and the position of the raphe, we are uncertain about its systematic placement at finer levels of classification.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153713/1/pre12400_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153713/2/pre12400.pd
Sellaphora balashovae (Bacillariophyta), a new species from siberian mountain lake frolikha (Baikal region), Russia
© 2018 Magnolia Press. A new species, Sellaphora balashovae sp. nov., from Lake Frolikha is described based on light (LM) and scanning electron microscopy (SEM). The systematic position of this new species is determined based on molecular data. This species is placed in the genus Sellaphora based on chloroplast morphology, areolae covered by external hymenes, and uniseriate striae that are typical for the genus. Molecular data support this taxonomic assignment, and the new species is part of a monophyletic group with some other members of the genus Sellaphora. The new species is distinguishable from other Sellaphora species by its small size, valve shape, striae and areolae densities, striae orientation and distinctly large areolae bordering the sternum
Search for muon-neutrino emission from GeV and TeV gamma-ray flaring blazars using five years of data of the ANTARES telescope
The ANTARES telescope is well-suited for detecting astrophysical transient
neutrino sources as it can observe a full hemisphere of the sky at all times
with a high duty cycle. The background due to atmospheric particles can be
drastically reduced, and the point-source sensitivity improved, by selecting a
narrow time window around possible neutrino production periods. Blazars, being
radio-loud active galactic nuclei with their jets pointing almost directly
towards the observer, are particularly attractive potential neutrino point
sources, since they are among the most likely sources of the very high-energy
cosmic rays. Neutrinos and gamma rays may be produced in hadronic interactions
with the surrounding medium. Moreover, blazars generally show high time
variability in their light curves at different wavelengths and on various time
scales. This paper presents a time-dependent analysis applied to a selection of
flaring gamma-ray blazars observed by the FERMI/LAT experiment and by TeV
Cherenkov telescopes using five years of ANTARES data taken from 2008 to 2012.
The results are compatible with fluctuations of the background. Upper limits on
the neutrino fluence have been produced and compared to the measured gamma-ray
spectral energy distribution.Comment: 27 pages, 16 figure
Measurement of the atmospheric muon depth intensity relation with the NEMO Phase-2 tower
The results of the analysis of the data collected with the NEMO Phase-2
tower, deployed at 3500 m depth about 80 km off-shore Capo Passero (Italy), are
presented. Cherenkov photons detected with the photomultipliers tubes were used
to reconstruct the tracks of atmospheric muons. Their zenith-angle distribution
was measured and the results compared with Monte Carlo simulations. An
evaluation of the systematic effects due to uncertainties on environmental and
detector parameters is also included. The associated depth intensity relation
was evaluated and compared with previous measurements and theoretical
predictions. With the present analysis, the muon depth intensity relation has
been measured up to 13 km of water equivalent.Comment: submitted to Astroparticle Physic
The Antares Collaboration : Contributions to the 34th International Cosmic Ray Conference (ICRC 2015, The Hague)
The ANTARES detector, completed in 2008, is the largest neutrino telescope in the Northern hemisphere. Located at a depth of 2.5 km in the Mediterranean Sea, 40 km off the Toulon shore, its main goal is the search for astrophysical high energy neutrinos. In this paper we collect the 21 contributions of the ANTARES collaboration to the 34th International Cosmic Ray Conference (ICRC 2015). The scientific output is very rich and the contributions included in these proceedings cover the main physics results, ranging from steady point sources, diffuse searches, multi-messenger analyses to exotic physics
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