81 research outputs found
Cascade events at IceCube + DeepCore as a definitive constraint on the dark matter interpretation of the PAMELA and Fermi anomalies
Dark matter decaying or annihilating into μ^+μ^- or τ^+τ^- has been proposed as an explanation for the e^± anomalies reported by PAMELA and Fermi. Recent analyses show that IceCube, supplemented by DeepCore, will be able to significantly constrain the parameter space of decays to μ^+μ^-, and rule out decays to τ^+τ^- and annihilations to μ^+μ^- in less than five years of running. These analyses rely on measuring tracklike events in IceCube + DeepCore from down-going ν_μ. In this paper we show that by instead measuring cascade events, which are induced by all neutrino flavors, IceCube + DeepCore can rule out decays to μ^+μ^- in only three years of running, and rule out decays to τ^+τ^- and annihilation to μ^+μ^- in only one year of running. These constraints are highly robust to the choice of dark matter halo profile and independent of dark matter-nucleon crosssection
Study on the effect of toxicity under highly arsenic prone zone in Nadia district of West Bengal in India
The present study was carried out on the basis of status of arsenic in soil, drinking water and plants, blood, urine and faeces of animals at arsenic prone zone. Within the ambit with the environment, the examination of animals was taken into consideration. They were screened and categorised on the degree of As toxicity. For field works animals were randomly selected from arsenic prone zone. The external manifestation indicated a complex syndrome and characteristic signs such as increased heart rate and respiratory rate, red urine, congested mucous membrane, anorexia, absence of ruminal motility, diarrhoea with blood, polyuria and unusual weight loss. The haematobiochemical changes such as low Hb level, decreased level of TEC, TLC and increased level ALT, AST, BUN and creatinine. Increased level of arsenic in urine, blood and faeces than the value of control animals could be the confirmatory indication of arsenic toxicity
Spectroscopic comprehension of Mott-Hubbard insulator to negative charge transfer metal transition in LaNi_{x}V_{1-x}O_{3} thin films
The room temperature (300 K) electronic structure of pulsed laser deposited
LaNi_{x}V_{1-x}O_{3} thin films have been demonstrated. The substitution of
early-transition metal (TM) V in LaVO_{3} thin films with late-TM Ni leads to
the decreasing in out-of-plane lattice parameter. Doping of Ni does not alter
the formal valence state of Ni and V in LaNi_{x}V_{1-x}O_{3} thin films,
divulging the absence of carrier doping into the system. The valence band
spectrum is observed to comprise of incoherent structure owing to the localized
V 3d band along with the coherent structure at Fermi level. With increase in Ni
concentration, the weight of the coherent feature increases, which divulges its
origin to the Ni 3d-O 2p hybridized band. The shift of Ni 3d-O 2p hybridized
band towards higher energy in Ni doped LaVO_{3} films compared to the LaNiO_{3}
film endorses the modification in ligand to metal charge transfer (CT) energy.
The Ni doping in Mott-Hubbard insulator LaVO_{3} leads to the closure of
Mott-Hubbard gap by building of spectral weight that provides the delocalized
electrons for conduction. A transition from bandwidth control Mott-Hubbard
insulator LaVO_{3} to negative CT metallicity character in LaNiO_{3} film is
observed. The study reveals that unlike in Mott-Hubbard insulators where the
strong Coulomb interaction between the 3d electrons decides the electronic
structure of the system, CT energy can deliver an additional degree of freedom
to optimize material properties in Ni doped LaVO_{3} films.Comment: 30 pages, 8 figure
Cherenkov Radiation from Pairs and Its Effect on Induced Showers
We calculate the Cherenkov radiation from an pair at small
separations, as occurs shortly after a pair conversion. The radiation is
reduced (compared to that from two independent particles) when the pair
separation is smaller than the wavelength of the emitted light. We estimate the
reduction in light in large electromagnetic showers, and discuss the
implications for detectors that observe Cherenkov radiation from showers in the
Earth's atmosphere, as well as in oceans and Antarctic ice.Comment: Final version, with minor changes, to appear in PRD. 5 pages with 4
figure
Testing the Nambu-Goldstone Hypothesis for Quarks and Leptons at the LHC
The hierarchy of the Yukawa couplings is an outstanding problem of the
standard model. We present a class of models in which the first and second
generation fermions are SUSY partners of pseudo-Nambu-Goldstone bosons that
parameterize a non-compact Kahler manifold, explaining the small values of
these fermion masses relative to those of the third generation. We also provide
an example of such a model. We find that various regions of the parameter space
in this scenario can give the correct dark matter abundance, and that nearly
all of these regions evade other phenomenological constraints. We show that for
gluino mass ~700 GeV, model points from these regions can be easily
distinguished from other mSUGRA points at the LHC with only 7 fb^(-1) of
integrated luminosity at 14 TeV. The most striking signatures are a dearth of
b- and tau-jets, a great number of multi-lepton events, and either an
"inverted" slepton mass hierarchy, narrowed slepton mass hierarchy, or
characteristic small-mu spectrum.Comment: Corresponds to published versio
High Resolution Methylome Map of Rat Indicates Role of Intragenic DNA Methylation in Identification of Coding Region
DNA methylation is crucial for gene regulation and maintenance of genomic stability. Rat has been a key model system in understanding mammalian systemic physiology, however detailed rat methylome remains uncharacterized till date. Here, we present the first high resolution methylome of rat liver generated using Methylated DNA immunoprecipitation and high throughput sequencing (MeDIP-Seq) approach. We observed that within the DNA/RNA repeat elements, simple repeats harbor the highest degree of methylation. Promoter hypomethylation and exon hypermethylation were common features in both RefSeq genes and expressed genes (as evaluated by proteomic approach). We also found that although CpG islands were generally hypomethylated, about 6% of them were methylated and a large proportion (37%) of methylated islands fell within the exons. Notably, we obeserved significant differences in methylation of terminal exons (UTRs); methylation being more pronounced in coding/partially coding exons compared to the non-coding exons. Further, events like alternate exon splicing (cassette exon) and intron retentions were marked by DNA methylation and these regions are retained in the final transcript. Thus, we suggest that DNA methylation could play a crucial role in marking coding regions thereby regulating alternative splicing. Apart from generating the first high resolution methylome map of rat liver tissue, the present study provides several critical insights into methylome organization and extends our understanding of interplay between epigenome, gene expression and genome stability
Top Polarization from Boosted Jet Substructure
Top polarization is an important probe of new physics that couples to the top sector, and which may be discovered at the 14 TeV LHC. Taking the example of the MSSM, we develop a detector level analysis methodology for extracting polarization information from hadronic tops using boosted jet substructure. We show that with 100 fb-1 of data, left and right 600 GeV stops can be distinguished to 4,5σ, and 800 GeV stops can be distinguished to 3σ
Top Polarization from Boosted Jet Substructure
Top polarization is an important probe of new physics that couples to the top sector, and which may be discovered at the 14 TeV LHC. Taking the example of the MSSM, we develop a detector level analysis methodology for extracting polarization information from hadronic tops using boosted jet substructure. We show that with 100 fb-1 of data, left and right 600 GeV stops can be distinguished to 4,5σ, and 800 GeV stops can be distinguished to 3σ
Surface wave interactions with submerged horizontal viscoelastic sheets
In this study, the surface wave interactions with submerged horizontal viscoelastic sheets of varying rheological properties are investigated both experimentally and analytically. In the experiments, we adopt the novel development in preparing finite length viscoelastic sheets with different rheological properties using oil-doped polydimethylsiloxane (PDMS) materials reported earlier in Sree et al. (2017, 2018). The wave interactions with the submerged viscoelastic sheets are quantified using ultrasonic sensors at different locations in terms of the reflection and transmission behavior. The experimental results show that the wave-sheet interactions are complex. The wave pattern at the submerged sheet region significantly depends on its rheological properties. For larger submergence, a standing wave pattern with primarily lower order modes develops along the sheet with a significant reduction of transmitted wave energy past the sheet region for shorter period waves. An almost complete cutoff (up to 99% reduction in wave energy transmission) occurs with the flexible sheet held close to the mean water level (MWL), while 50-90% reduction in wave energy transmission is recorded with the stiffer sheets. An analytical study is also carried out under the assumption of small amplitude water wave theory. The sheet is modeled based on the viscoelastic representation of the Voigt model and the analytical problem is solved using the domain matching technique. The profiles of surface wave as well as sheet displacement are well predicted by the analysis compared to the experimental measurements. However, the displacement amplitude is underestimated due to the fixed end conditions assumed. The predicted dispersion relation for the surface waves also agrees well with the experimental results for the shorter period waves, however larger discrepancies are observed with longer wave periods. In addition, the experimental results are up to one order of magnitude higher with respect to wave reflection. Thus, further improvement is needed in the future for the analysis to better represent the surface wave interactions with submerged viscoelastic sheets.Nanyang Technological UniversitySubmitted/Accepted versionThis research study is funded by the internal core funding from the Nanyang Environment and Water Research Institute (NEWRI), Nanyang Technological university
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