348 research outputs found
Analysis of Fermi-LAT data from Tucana-II: Possible constraints on the Dark Matter models with an intriguing hint of a signal
Tucana-II (Tuc-II), a recently discovered and confirmed Ultra Faint Dwarf
Spheroidal galaxy, has a high mass to light ratio as well as a large
line-of-sight stellar velocity dispersion, thus making it an ideal candidate
for an indirect dark matter (DM) search. In this paper, we have analyzed nine
years of -ray data obtained from the \textit{Fermi}-LAT instrument from
the direction of Tuc-II. The fact that a very weak significant -ray
excess () over the background of Tuc-II have been detected from the
location of this galaxy. We have observed that this excess of -ray
emission from the of location Tuc-II rises with longer periods of data. If WIMP
pair annihilation is assumed for this faint emission, for
annihilation channel the test statistics (TS) value peaks at DM mass 14
GeV and for annihilation channel it peaks at DM mass 4 GeV.
It is then called for an estimation of the confidence level upper limit
of the possible velocity weighted self-annihilation cross-section of the DM
particles (WIMPs) within Tuc-II by fitting the observed -ray flux with
spectra expected for DM annihilation. The estimated upper limits of the
cross-sections from Tuc-II are then compared with two other dwarf galaxies that
are considered to be good DM candidates in several studies. We have also
compared our results with the cross-sections obtained in various popular
theoretical models of the WIMPs to find that our results impose reasonable
tight constraints on the parameter spaces of those DM models. In the concluding
section, we compared our results with the similar results obtained from a
combined dSph analysis by the \textit{Fermi}-LAT collaboration as well as the
results obtained from the studies of DM in the dwarf galaxies by the major
ground-based Cherenkov experiments.Comment: 23 pages, 16 figures, 7 table
Investigating the region of 3C 397 in High Energy Gamma rays
We investigate the supernova remnant (SNR) 3C 397 and its neighboring pulsar
PSR J1906+0722 in high energy gamma rays by using nearly six years of archival
data of {\it Large Area Telescope} on board {\it Fermi Gamma Ray Space
Telescope} (Fermi-LAT). The off-pulse analysis of gamma-ray flux from the
location of PSR J1906+0722 reveals an excess emission which is found to be very
close to the radio location of 3C 397. Here, we present the preliminary results
of this gamma-ray analysis of 3C 397 and PSR J1906+0722.Comment: 4 pages, 3 figures, Proceeding of IAU Symposium No. 331, 201
A Novel Rare Sugar Inhibitor of Murine Herpes Simplex Keratitis.
Purpose To determine the therapeutic efficacy of a novel rare sugar, L-psicose, for the treatment of HSV-1 induced herpetic stromal keratitis (HSK) in a mouse eye model. Methods One rare sugar L-psicose was assayed for HSV-1 inhibition of in vitro virus adsorption. The IC50 and IC90 values of L-psicose were determined using plaque reduction assay (PRA) in CV-1 cell. Female Balb/c mice were corneally infected with HSV-1, strain KOS-GFP; A topical eye drop treatment of L-psicose was started 24 h after infection and continued four times daily for ten consecutive days. The severity of HSK was monitored by slit lamp examination in a masked fashion and Infectious HSV-1 shedding was determined by PRA. Results L-psicose was found to have anti-viral activity in vitro at an IC50 dose of 99.5 mM and an IC90 dose of 160 mM. Topical eye drop treatment with 200 mM L-psicose in PBS solution significantly reduced the severity of HSK compared to the mock treatment group. The in vivo mouse ocular model results of L-psicose therapy correlated with accelerated clearance of virus from eye swabs. Conclusion The results suggest that topical treatment with rare sugar L-psicose has efficacy against HSK through inhibition of HSV-1
Wound healing promoting activity of Earthworm, Eutyphoeus gammiei (Beddard): in vitro studies on human skin keratinocyte cell line (HaCat).
Earthworm, Eutyphoeus gammiei, homogenate (EGH) was screened for wound healing activity on human keratinocyte cell line, HaCat, by cell proliferation and migration assays. The maximum proliferation and migration of keratinocyte cells were observed at the dose of 25μg/ml. As cell proliferation and migration are key factors for wound healing, the study clearly suggests the potential role of earthworm species Eutyphoeus gammiei on wound healing.
Keywords: Eutyphoeus gammiei, Keratinocyte, MTT assay, scratch assay
An Early Assessment of Medium Range Monsoon Precipitation Forecasts from the Latest High-Resolution NCEP-GFS (T1534) Model over South Asia
Reliable prediction of the South Asian monsoon rainfall and its variability is crucial for various hydrological applications and early warning systems. The National Centers for Environmental Prediction – Global Forecast System (NCEP–GFS) is one of the popular global deterministic numerical weather prediction models, which is recently upgraded from T574 to T1534. In this paper, medium range monsoon precipitation forecasts from both the T1534 and T574 models are critically evaluated over the South Asia for the peak monsoon months (July and August) of 2015. Although both the versions of GFS model show similar large-scale monsoon rainfall patterns, the dry bias over the northwest India and equatorial Indian Ocean is noticeably improved in day-1 through day-5 forecasts in the new high-resolution T1534 model. The error decomposition analysis shows similar error characteristics in the monsoon rainfall prediction from both the versions of GFS model, in general. However, forecast improvement factor shows 10-30% improvement in precipitation forecast from the latest T1534 model over most parts of the South Asia. These preliminary analyses suggest that a suitable bias-correction to the GFS model precipitation forecasts will be useful for any specific application
The Implementation of NEMS GFS Aerosol Component (NGAC) Version 1.0 for Global Dust Forecasting at NOAA NCEP
The NOAA National Centers for Environmental Prediction (NCEP) implemented the NOAA Environmental Modeling System (NEMS) Global Forecast System (GFS) Aerosol Component (NGAC) for global dust forecasting in collaboration with NASA Goddard Space Flight Center (GSFC). NGAC Version 1.0 has been providing 5-day dust forecasts at 1deg x 1deg resolution on a global scale, once per day at 00:00 Coordinated Universal Time (UTC), since September 2012. This is the first global system capable of interactive atmosphere aerosol forecasting at NCEP. The implementation of NGAC V1.0 reflects an effective and efficient transitioning of NASA research advances to NCEP operations, paving the way for NCEP to provide global aerosol products serving a wide range of stakeholders, as well as to allow the effects of aerosols on weather forecasts and climate prediction to be considered
A Novel Peptide Derived from Human Apolipoprotein E Is an Inhibitor of Tumor Growth and Ocular Angiogenesis
Angiogenesis is a hallmark of tumor development and metastasis and now a validated target for cancer treatment. We previously reported that a novel dimer peptide (apoEdp) derived from the receptor binding region of human apolipoprotein E (apoE) inhibits virus-induced angiogenesis. However, its role in tumor anti-angiogenesis is unknown. This study demonstrates that apoEdp has anti-angiogenic property in vivo through reduction of tumor growth in a mouse model and ocular angiogenesis in a rabbit eye model. Our in vitro studies show that apoEdp inhibits human umbilical vein endothelial cell proliferation, migration, invasion and capillary tube formation. We document that apoEdp inhibits vascular endothelial growth factor-induced Flk-1 activation as well as downstream signaling pathways that involve c-Src, Akt, eNOS, FAK, and ERK1/2. These in vitro data suggest potential sites of the apoE dipeptide inhibition that could occur in vivo
Current and emerging developments in subseasonal to decadal prediction
Weather and climate variations of subseasonal to decadal timescales can have enormous social, economic and environmental impacts, making skillful predictions on these timescales a valuable tool for decision makers. As such, there is a growing interest in the scientific, operational and applications communities in developing forecasts to improve our foreknowledge of extreme events. On subseasonal to seasonal (S2S) timescales, these include high-impact meteorological events such as tropical cyclones, extratropical storms, floods, droughts, and heat and cold waves. On seasonal to decadal (S2D) timescales, while the focus remains broadly similar (e.g., on precipitation, surface and upper ocean temperatures and their effects on the probabilities of high-impact meteorological events), understanding the roles of internal and externally-forced variability such as anthropogenic warming in forecasts also becomes important.
The S2S and S2D communities share common scientific and technical challenges. These include forecast initialization and ensemble generation; initialization shock and drift; understanding the onset of model systematic errors; bias correct, calibration and forecast quality assessment; model resolution; atmosphere-ocean coupling; sources and expectations for predictability; and linking research, operational forecasting, and end user needs. In September 2018 a coordinated pair of international conferences, framed by the above challenges, was organized jointly by the World Climate Research Programme (WCRP) and the World Weather Research Prograame (WWRP). These conferences surveyed the state of S2S and S2D prediction, ongoing research, and future needs, providing an ideal basis for synthesizing current and emerging developments in these areas that promise to enhance future operational services. This article provides such a synthesis
Benchmarking and Safety Assessment for Modified Lateral Spreading Design Procedure using Three-Dimensional Nonlinear Finite Element Analysis
Liquefaction-induced lateral spreading is a critical design consideration for many bridges in high-seismicity regions of the Pacific Northwest, with broad impacts on safety for the general public. The bridge design procedures currently used in the region tend to account for the effects of lateral spreading in a simplified manner that captures the general impact of this phenomenon on the bridge components but omits many key details such as three-dimensional soil deformation. Modifications to this current design approach will not only lead to more cost-effective design solutions, but will increase public safety by reducing the potential for bridge collapse and minimizing lost service time. An improved design framework has been proposed to supplant the current method; however, relatively little focus has been given to the validation and verification of this new procedure. Before widespread acceptance of this modified approach, it is critical to verify that its application will result in improved design solutions that reduce the costs associated with the conventional approach while remaining safe for use. This work aims to verify the modified simplified design procedure against 3D finite element models and to increase our understanding of the site geometry conditions that necessitate a more comprehensive consideration of 3D effects in foundation design by using a large parameter study.Pacific Northwest Transportation Consortiu
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