664 research outputs found
Pleiotropic functions of the tumor- and metastasis-suppressing Matrix Metalloproteinase-8 in mammary cancer in MMTV-PyMT transgenic mice
Matrix metalloproteinase-8 (MMP-8; neutrophil collagenase) is an important regulator of innate immunity which has onco-suppressive actions in numerous tumor types
High-Dispersion Spectroscopic Observations of Comet C/2012 S1 (ISON) with the Subaru Telescope
Comet C/2012 S1 (ISON) was one of the Oort cloud comets and dynamically new. This comet was broken at its perihelion passage on UT 2013 November 28.1 (at Rh ~ 17 solar radius). We observed the comet C/2012 S1 (ISON) on UT 2013 November 15 with the High Dispersion Spectrograph (HDS) mounted on the Subaru Telescope atop Mauna Kea, Hawaii. Its heliocentric and geocentric distances were 0.601 and 0.898 AU, respectively. We selected the slit size of 0”.5 x 9”.0 on the sky to achieve the spectral resolution of R = 72,000 from 550 to 830 nm. The total exposure time of comet C/2012 S1 (ISON) was 1200 seconds. We detected many emission lines caused from radicals (e.g., CN, C2, NH2), ions (H2O+), atoms ([OI] and Na I) and also many unidentified lines in the spectra. We report the (1) the ortho-to-para abundance ratios (OPRs) of water and ammonia estimated from the high-dispersion spectra of H2O+ and NH2, (2) the green-to-red line ratio of forbidden oxygen emissions, (3) the isotopic ratios of C2 (the carbon isotopic ratio from Swan band) and CN (the carbon and nitrogen isotopic ratios from red band), (4) the sodium-to-continuum ratio of comet C/2012 S1 (ISON). </HTML
Detection of variable VHE gamma-ray emission from the extra-galactic gamma-ray binary LMC P3
Context. Recently, the high-energy (HE, 0.1-100 GeV) -ray emission
from the object LMC P3 in the Large Magellanic Cloud (LMC) has been discovered
to be modulated with a 10.3-day period, making it the first extra-galactic
-ray binary.
Aims. This work aims at the detection of very-high-energy (VHE, >100 GeV)
-ray emission and the search for modulation of the VHE signal with the
orbital period of the binary system.
Methods. LMC P3 has been observed with the High Energy Stereoscopic System
(H.E.S.S.); the acceptance-corrected exposure time is 100 h. The data set has
been folded with the known orbital period of the system in order to test for
variability of the emission. Energy spectra are obtained for the orbit-averaged
data set, and for the orbital phase bin around the VHE maximum.
Results. VHE -ray emission is detected with a statistical
significance of 6.4 . The data clearly show variability which is
phase-locked to the orbital period of the system. Periodicity cannot be deduced
from the H.E.S.S. data set alone. The orbit-averaged luminosity in the
TeV energy range is erg/s. A luminosity of erg/s is reached during 20% of the orbit. HE and VHE
-ray emissions are anti-correlated. LMC P3 is the most luminous
-ray binary known so far.Comment: 5 pages, 3 figures, 1 table, accepted for publication in A&
Characterizing the gamma-ray long-term variability of PKS 2155-304 with H.E.S.S. and Fermi-LAT
Studying the temporal variability of BL Lac objects at the highest energies
provides unique insights into the extreme physical processes occurring in
relativistic jets and in the vicinity of super-massive black holes. To this
end, the long-term variability of the BL Lac object PKS 2155-304 is analyzed in
the high (HE, 100 MeV 200 GeV)
gamma-ray domain. Over the course of ~9 yr of H.E.S.S observations the VHE
light curve in the quiescent state is consistent with a log-normal behavior.
The VHE variability in this state is well described by flicker noise
(power-spectral-density index {\ss}_VHE = 1.10 +0.10 -0.13) on time scales
larger than one day. An analysis of 5.5 yr of HE Fermi LAT data gives
consistent results ({\ss}_HE = 1.20 +0.21 -0.23, on time scales larger than 10
days) compatible with the VHE findings. The HE and VHE power spectral densities
show a scale invariance across the probed time ranges. A direct linear
correlation between the VHE and HE fluxes could neither be excluded nor firmly
established. These long-term-variability properties are discussed and compared
to the red noise behavior ({\ss} ~ 2) seen on shorter time scales during
VHE-flaring states. The difference in power spectral noise behavior at VHE
energies during quiescent and flaring states provides evidence that these
states are influenced by different physical processes, while the compatibility
of the HE and VHE long-term results is suggestive of a common physical link as
it might be introduced by an underlying jet-disk connection.Comment: 11 pages, 16 figure
Workgroup report: Public health strategies for reducing aflatoxin exposure in developing countries
10.1289/ehp.9302Environmental Health Perspectives114121898-190
Effect of Copper And/Or Bacitracin On The Sulphur Amino Acid Requirements Of Turkeys
A nonsignificant but consistent depressing effects from additions of combined copper (120 ppm) and zinc bacitracin (50 or 75 g per ton) was observed in a previous study. One of the factors that has been suspected to be affected by copper is utilization of sulfur containing amino acids. Thus, a factorial experiment was conducted to study the effect of copper (120 ppm) and/or zinc bacitracin (25 g per ton) on the level of sulfur amino acids at 85%, 100% and 115% of NRC (1977) requirements. The low protein density series of Guenthner et al. (1978) was used (23, 20, 18, 16, 14 and 12%). Dietary protein level was reduced at 4-week intervals
Conv-NILM-Net, a causal and multi-appliance model for energy source separation
Non-Intrusive Load Monitoring (NILM) seeks to save energy by estimating
individual appliance power usage from a single aggregate measurement. Deep
neural networks have become increasingly popular in attempting to solve NILM
problems. However most used models are used for Load Identification rather than
online Source Separation. Among source separation models, most use a
single-task learning approach in which a neural network is trained exclusively
for each appliance. This strategy is computationally expensive and ignores the
fact that multiple appliances can be active simultaneously and dependencies
between them. The rest of models are not causal, which is important for
real-time application. Inspired by Convtas-Net, a model for speech separation,
we propose Conv-NILM-net, a fully convolutional framework for end-to-end NILM.
Conv-NILM-net is a causal model for multi appliance source separation. Our
model is tested on two real datasets REDD and UK-DALE and clearly outperforms
the state of the art while keeping a significantly smaller size than the
competing models.Comment: Published in ECMLPKDD 2022, MLBEM worksho
The Science of Sungrazers, Sunskirters, and Other Near-Sun Comets
This review addresses our current understanding of comets that venture close to the Sun, and are hence exposed to much more extreme conditions than comets that are typically studied from Earth. The extreme solar heating and plasma environments that these objects encounter change many aspects of their behaviour, thus yielding valuable information on both the comets themselves that complements other data we have on primitive solar system bodies, as well as on the near-solar environment which they traverse. We propose clear definitions for these comets: We use the term near-Sun comets to encompass all objects that pass sunward of the perihelion distance of planet Mercury (0.307 AU). Sunskirters are defined as objects that pass within 33 solar radii of the Sun’s centre, equal to half of Mercury’s perihelion distance, and the commonly-used phrase sungrazers to be objects that reach perihelion within 3.45 solar radii, i.e. the fluid Roche limit. Finally, comets with orbits that intersect the solar photosphere are termed sundivers. We summarize past studies of these objects, as well as the instruments and facilities used to study them, including space-based platforms that have led to a recent revolution in the quantity and quality of relevant observations. Relevant comet populations are described, including the Kreutz, Marsden, Kracht, and Meyer groups, near-Sun asteroids, and a brief discussion of their origins. The importance of light curves and the clues they provide on cometary composition are emphasized, together with what information has been gleaned about nucleus parameters, including the sizes and masses of objects and their families, and their tensile strengths. The physical processes occurring at these objects are considered in some detail, including the disruption of nuclei, sublimation, and ionisation, and we consider the mass, momentum, and energy loss of comets in the corona and those that venture to lower altitudes. The different components of comae and tails are described, including dust, neutral and ionised gases, their chemical reactions, and their contributions to the near-Sun environment. Comet-solar wind interactions are discussed, including the use of comets as probes of solar wind and coronal conditions in their vicinities. We address the relevance of work on comets near the Sun to similar objects orbiting other stars, and conclude with a discussion of future directions for the field and the planned ground- and space-based facilities that will allow us to address those science topics
Fungal Planet description sheets: 320–370
Novel species of fungi described in the present study include the following from Malaysia: Castanediella eucalypti from Eucalyptus pellita, Codinaea acacia from Acacia man glum, Emarcea eucalyptigena from Eucalyptus brassiana, Myrtapenidiella eucalyptorum from Eucalyptus peffita, Pilidiella eucalyptigena from Eucalyptus brassiana and Strelitziana malaysiana from Acacia man glum. Furthermore, Stachybotrys sansevieriicola is described from Sansevieria ehrenbergii (Tanzania), Phacidium grevilleae from Grevillea robusta (Uganda), Graphium jumulu from Adansonia gregorii and Ophiostoma eucalyptigena from Eucalyptus marginata (Australia), Pleurophoma ossicola from bone and Plectosphaerella populi from Populus nigra (Germany), Colletotrichum neosansevieriae from Sansevieria L;/QSZLAKCVEQL,Atrifasciata, Elsinoe othonnae from Othonna quinquedentata and Zeloasperisporium cliviae (Zeloasperisporiaceae tam. nov.) from Clivia sp. (South Africa), Neodevriesia pakbiae, Phaeophleospora hymenocallidis and Phaeophleospora hymenocallidicola on leaves of a fern (Thailand), Melanconium elaeidicola from Elaeis guineensis (Indonesia), Hormonema viticola from Vitis vinifera (Canary Islands), Chlorrophyllum pseudoglobossum from a grassland (India), Triadelphia disseminata from an immunocompromised patient (Saudi Arabia), Colletotrichum abscissum from Citrus (Brazil), Polyschema sclerotigenum and Phialemonium limoniforme from human patients (USA), Cadophora viticola from Vitis vinifera (Spain), Entoloma flavovelutinum and Bolbitius aura ntiorugosus from soil (Vietnam), Rhizopogon granuloflavus from soil (Cape Verde Islands), Tulasnella eremophila from Euphorbia officinarum subsp. echinus (Morocco), Verrucostoma martinicensis from Danaea elliptica (French West Indies), Metschnikowia colchici from Colchicum autumnale (Bulgaria), Thelebolus microcarpus from soil (Argentina) and Ceratocystis adelpha from Theobroma cacao (Ecuador). Myrmecridium iridis (Mynnecridiales ord. nov., Myrmecridiaceae fam. nov.) is also described from Iris sp. (The Netherlands). Novel genera include (Ascomycetes): Budhanggurabania from Cynodon dactylon (Australia), Soloacrosporiella, Xenocamatrosporium, Neostrelitziana and Castanediella from Acacia man glum and Sabahriopsis from Eucalyptus brassiana (Malaysia), Readerielliopsis from basidiomata of Fuscopotia wahlbergii (French Guyana), Neoplatysporoides from Aloe ferox (Tanzania), Wojnowiciella, Chrysofolia and Neoeriomycopsis from Eucalyptus (Colombia), Neophaeomoniella from Eucalyptus globulus (USA), Pseudophaeomoniella from Olea europaea (Italy), Paraphaeomoniella from Encephalartos altensteinii, Aequabiliella, Celerioriella and Minutiella from Prunus (South Africa). Tephrocybella (Basidiomycetes) represents a novel genus from wood (Italy). Morphological and culture characteristics along with ITS DNA barcodes are provided for all taxa
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
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