We present results from an analysis looking for dark matter annihilation in the Sun with the IceCube neutrino telescope. Gravitationally trapped dark matter in the Sun’s core can annihilate into ...Standard Model particles making the Sun a source of GeV neutrinos. IceCube is able to detect neutrinos with energies >100 GeV while its low-energy infill array DeepCore extends this to >10 GeV. This analysis uses data gathered in the austral winters between May 2011 and May 2014, corresponding to 532 days of livetime when the Sun, being below the horizon, is a source of up-going neutrino events, easiest to discriminate against the dominant background of atmospheric muons. The sensitivity is a factor of two to four better than previous searches due to additional statistics and improved analysis methods involving better background rejection and reconstructions. The resultant upper limits on the spin-dependent dark matter-proton scattering cross section reach down to
1.46
×
10
-
5
pb for a dark matter particle of mass 500 GeV annihilating exclusively into
τ
+
τ
-
particles. These are currently the most stringent limits on the spin-dependent dark matter-proton scattering cross section for WIMP masses above 50 GeV.
We present a search for a neutrino signal from dark matter self-annihilations in the Milky Way using the IceCube Neutrino Observatory (IceCube). In 1005 days of data we found no significant excess of ...neutrinos over the background of neutrinos produced in atmospheric air showers from cosmic ray interactions. We derive upper limits on the velocity averaged product of the dark matter self-annihilation cross section and the relative velocity of the dark matter particles
⟨
σ
A
v
⟩
. Upper limits are set for dark matter particle candidate masses ranging from 10 GeV up to 1 TeV while considering annihilation through multiple channels. This work sets the most stringent limit on a neutrino signal from dark matter with mass between 10 and 100 GeV, with a limit of
1.18
·
10
-
23
cm
3
s
-
1
for 100 GeV dark matter particles self-annihilating via
τ
+
τ
-
to neutrinos (assuming the Navarro–Frenk–White dark matter halo profile).
A considerable number of single nucleotide polymorphisms (SNPs) are required to elucidate genotype–phenotype associations and determine the molecular basis of important traits. In this work, we ...carried out de novo SNP discovery accounting for both genome duplication and genetic variation from American and European salmon populations. A total of 9 736 473 nonredundant SNPs were identified across a set of 20 fish by whole‐genome sequencing. After applying six bioinformatic filtering steps, 200 K SNPs were selected to develop an Affymetrix Axiom® myDesign Custom Array. This array was used to genotype 480 fish representing wild and farmed salmon from Europe, North America and Chile. A total of 159 099 (79.6%) SNPs were validated as high quality based on clustering properties. A total of 151 509 validated SNPs showed a unique position in the genome. When comparing these SNPs against 238 572 markers currently available in two other Atlantic salmon arrays, only 4.6% of the SNP overlapped with the panel developed in this study. This novel high‐density SNP panel will be very useful for the dissection of economically and ecologically relevant traits, enhancing breeding programmes through genomic selection as well as supporting genetic studies in both wild and farmed populations of Atlantic salmon using high‐resolution genomewide information.
Structural heart disease as the cause of syncope Guimarães, R B; Essebag, V; Furlanetto, M ...
Brazilian Journal of Medical and Biological Research,
01/2018, Volume:
51, Issue:
4
Journal Article
Peer reviewed
Open access
We described the clinical evolution of patients with structural heart disease presenting at the emergency room with syncope. Patients were stratified according to their syncope etiology and available ...scores for syncope prognostication. Cox proportional hazard models were used to investigate the relationship between etiology of the syncope and event-free survival. Of the 82,678 emergency visits during the study period, 160 (0.16%) patients were there due to syncope, having a previous diagnosis of structural heart disease. During the median follow-up of 33.8±13.8 months, mean age at the qualifying syncope event was 68.3 years and 40.6% of patients were male. Syncope was vasovagal in 32%, cardiogenic in 57%, orthostatic hypotension in 6%, and of unknown causes in 5% of patients. The primary composite endpoint death, readmission, and emergency visit in 30 days was 39.4% in vasovagal syncope and 60.6% cardiogenic syncope (P<0.001). Primary endpoint-free survival was lower for patients with cardiogenic syncope (HR=2.97, 95%CI=1.94-4.55; P<0.001). The scores were analyzed for diagnostic performance with area under the curve (AUC) and did not help differentiate patients with an increased risk of adverse events. The differential diagnosis of syncope causes in patients with structural heart disease is important, because vasovagal and postural hypotension have better survival and less probability of emergency room or hospital readmission. The available scores are not reliable tools for prognosis in this specific patient population.
Aims
To produce and characterize egg yolk immunoglobulin (IgY) against the fish intracellular pathogen Piscirickettsia salmonis as well as to evaluate the antibacterial activity of IgY in vitro and ...the availability in the serum of fish immunized orally.
Methods and Results
Specific IgY was produced by immunizing hens with P. salmonis proteins. The IgY was obtained from egg yolks using the ammonium sulphate precipitation method and it was characterized by SDS‐PAGE, Western‐blot and ELISA, demonstrating that anti‐P. salmonis IgY strongly reacted specifically against P. salmonis proteins. In an in vitro neutralization assay, IgY inhibited the growth of P. salmonis in liquid medium at concentrations ranging from 128 to 256 μg ml−1 in a dose‐dependent manner. Interestingly, IgY against P. salmonis also generates a strong protective effect on the infection of P. salmonis in salmon head kidney‐1 cells. In addition, the bacteriostatic function of IgY appears to result possibly from agglutination by the interaction of IgY with surface components of the pathogen. Finally, to confirm this IgY as an alternative for salmonid treatment, Atlantic salmon (Salmo salar) specimens were orally inoculated with IgY. The analysis of the sera demonstrates that IgY was effectively transported by fish intestine and that this immunoglobulins maintains its properties and recognizes several proteins of P. salmonis up to 12 h after inoculation of IgY against P. salmonis.
Conclusions
Specific IgY effectively inhibited the growth of P. salmonis and this immunoglobulin can be released in the Atlantic salmon sera when administered orally to fish.
Significance and Impact of the Study
We propose that this specific IgY against this fastidious micro‐organism could be a useful strategy for the treatment of piscirickettsiosis.
We present results on searches for point-like sources of neutrinos using four years of IceCube data, including the first year of data from the completed 86 string detector. The total livetime of the ...combined data set is 1373 days. For an E super(-2) spectrum, the observed 90% C.L. flux upper limits are ~10 super(-12) TeV super(-1) cm super(-2) s super(-1) for energies between 1 TeV and 1 PeV in the northern sky and ~10 super(-11) TeV super(-1) cm super(-2) s super(-1) for energies between 100 TeV and 100 PeV in the southern sky. This represents a 40% improvement compared to previous publications, resulting from both the additional year of data and the introduction of improved reconstructions. In addition, we present the first results from an all-sky search for extended sources of neutrinos. We update the results of searches for neutrino emission from stacked catalogs of sources and test five new catalogs; two of Galactic supernova remnants and three of active galactic nuclei. In all cases, the data are compatible with the background-only hypothesis, and upper limits on the flux of muon neutrinos are reported for the sources considered.
Abstract
In multi-messenger astronomy, rapid investigation of interesting transients is imperative. As an observatory with a 4
π
steradian field of view, and ∼99% uptime, the IceCube Neutrino ...Observatory is a unique facility to follow up transients, as well as to provide valuable insights for other observatories and inform their observational decisions. Since 2016, IceCube has been using low-latency data to rapidly respond to interesting astrophysical events reported by the multi-messenger observational community. Here, we describe the pipeline used to perform these followup analyses, and provide a summary of the 58 analyses performed as of July 2020. We find no significant signal in the first 58 analyses performed. The pipeline has helped inform various electromagnetic observation strategies, and has constrained neutrino emission from potential hadronic cosmic accelerators.
This paper describes the response of the IceCube neutrino telescope located at the geographic south pole to outbursts of MeV neutrinos from the core collapse of nearby massive stars. IceCube was ...completed in December 2010 forming a lattice of 5160 photomultiplier tubes that monitor a volume of ~1 km3 in the deep Antarctic ice for particle induced photons. The telescope was designed to detect neutrinos with energies greater than 100 GeV. Owing to subfreezing ice temperatures, the photomultiplier dark noise rates are particularly low. Hence IceCube can also detect large numbers of MeV neutrinos by observing a collective rise in all photomultiplier rates on top of the dark noise. With 2 ms timing resolution, IceCube can detect subtle features in the temporal development of the supernova neutrino burst. For a supernova at the galactic center, its sensitivity matches that of a background-free megaton-scale supernova search experiment. The sensitivity decreases to 20 standard deviations at the galactic edge (30 kpc) and 6 standard deviations at the Large Magellanic Cloud (50 kpc). IceCube is sending triggers from potential supernovae to the Supernova Early Warning System. The sensitivity to neutrino properties such as the neutrino hierarchy is discussed, as well as the possibility to
The IceCube Neutrino Observatory has observed a diffuse flux of TeV-PeV astrophysical neutrinos at 5.7sigma significance from an all-flavor search. The direct detection of tau neutrinos in this flux ...has yet to occur. Tau neutrinos become distinguishable from other flavors in IceCube at energies above a few hundred TeV, when the cascade from the tau neutrino charged current interaction becomes resolvable from the cascade from the tau lepton decay. This paper presents results from the first dedicated search for tau neutrinos with energies between 214 TeV and 72 PeV in the full IceCube detector. The analysis searches for IceCube optical sensors that observe two separate pulses in a single event-one from the tau neutrino interaction and a second from the tau decay. No candidate events were observed in three years of IceCube data. For the first time, a differential upper limit on astrophysical tau neutrinos is derived around the PeV energy region, which is nearly 3 orders of magnitude lower in energy than previous limits from dedicated tau neutrino searches.
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