1,084 research outputs found

    Neutrino flavor ratios as diagnostic of solar WIMP annihilation

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    We consider the neutrino (and antineutrino) flavors arriving at Earth for neutrinos produced in the annihilation of weakly interacting massive particles (WIMPs) in the Sun's core. Solar-matter effects on the flavor propagation of the resulting \agt GeV neutrinos are studied analytically within a density-matrix formalism. Matter effects, including mass-state level-crossings, influence the flavor fluxes considerably. The exposition herein is somewhat pedagogical, in that it starts with adiabatic evolution of single flavors from the Sun's center, with θ13\theta_{13} set to zero, and progresses to fully realistic processing of the flavor ratios expected in WIMP decay, from the Sun's core to the Earth. In the fully realistic calculation, non-adiabatic level-crossing is included, as are possible nonzero values for θ13\theta_{13} and the CP-violating phase δ\delta. Due to resonance enhancement in matter, nonzero values of θ13\theta_{13} even smaller than a degree can noticeably affect flavor propagation. Both normal and inverted neutrino-mass hierarchies are considered. Our main conclusion is that measuring flavor ratios (in addition to energy spectra) of \agt GeV solar neutrinos can provide discrinination between WIMP models. In particular, we demonstrate the flavor differences at Earth for neutrinos from the two main classes of WIMP final states, namely W+WW^+ W^- and 95% bbˉb \bar{b} + 5% τ+τ\tau^+\tau^-. Conversely, if WIMP properties were to be learned from production in future accelerators, then the flavor ratios of \agt GeV solar neutrinos might be useful for inferring θ13\theta_{13} and the mass hierarchy.Comment: 30 pages, including 10 figures and 4 appendice

    Cluster and group synchronization in delay-coupled networks

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    We investigate the stability of synchronized states in delay-coupled networks where synchronization takes place in groups of different local dynamics or in cluster states in networks with identical local dynamics. Using a master stability approach, we find that the master stability function shows a discrete rotational symmetry depending on the number of groups. The coupling matrices that permit solutions on group or cluster synchronization manifolds show a very similar symmetry in their eigenvalue spectrum, which helps to simplify the evaluation of the master stability function. Our theory allows for the characterization of stability of different patterns of synchronized dynamics in networks with multiple delay times, multiple coupling functions, but also with multiple kinds of local dynamics in the networks' nodes. We illustrate our results by calculating stability in the example of delay-coupled semiconductor lasers and in a model for neuronal spiking dynamics.Comment: 11 pages, 7 figure

    Plan beta: Core or Cusp?

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    The inner profile of Dark Matter (DM) halos remains one of the central problems in small-scale cosmology. At present, the problem can not be resolved in dwarf spheroidal galaxies due to a degeneracy between the DM profile and the velocity anisotropy beta of the stellar population. We discuss a method which can break the degeneracy by exploiting 3D positions and 1D line-of-sight (LOS) velocities. With the full 3D spatial information, we can determine precisely what fraction of each stars LOS motion is in the radial and tangential direction. This enables us to infer the anisotropy parameter beta directly from the data. The method is particularly effective if the galaxy is highly anisotropic. Finally, we argue that such a test could be applied to Sagittarius and potentially other dwarfs with RR Lyrae providing the necessary depth information.Comment: 10 pages, 3 figures Accepted in MNRAS. Extended introduction to match accepted version. Main conclusions unchange

    Pancreatic pseudocyst eroding into the splenoportal venous confluence and mimicking an arterial aneurysm

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    We report the case of a 62-year-old man with chronic pancreatitis who presented with increasing abdominal pain. Sonography, magnetic resonance imaging, contrast-enhanced computed tomography, and ultimately catheter angiography demonstrated a pancreatic pseudocyst that had eroded into the splenoportal venous confluence, mimicking an arterial aneurysm. The diagnostic was confirmed at the time of surgical treatment. This case demonstrates the use of imaging to diagnose complications of pancreatitis, and the difficulty of distinguishing an eroding pseudocyst from an arterial aneurysm

    On the search for the vernalization locus in caraway (Carum carvi) using genotyping by sequencing data

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    Kümmel (Carum carvi) kann in zweijährige und einjährige Blühtypen unterteilt werden. Zweijährige benötigen einen Kältereiz für die Blühinduktion, während Einjährige keinen Vernalisationsbedarf haben. Aufgrund der besseren Integration in die Fruchtfolge und der geringeren Produktionskosten wird der Anbau Einjähriger als vorteilhaft angesehen. Die verfügbaren einjährigen Sorten weisen jedoch ein unzureichendes Ertragspotential und einen zu geringen Ätherischölgehalt auf. Der zweijährige Genpool enthält wertvolle genetische Diversität, die durch Kreuzungen auf den einjährigen Genpool übertragen werden kann. Laut Literatur zeigen F1-Pflanzen aus Kreuzungen zwischen ein- und zweijährigen Blühtypen ein uniform einjähriges Blühverhalten. Resultierende F2-Populationen zeigen ein Mendelsches 3:1-Verhältnis zwischen einjährigen und zweijährigen Blühtypen. Dies deutet auf eine monogenetische Vererbung der Vernalisation beim Kümmel mit dominanter Einjährigkeit hin. Nach Kreuzungen zwischen ein- und zweijährigen Blühtypen kann das rezessive Allel für die zweijährige Blüte über mehrere Generationen im Zuchtmaterial verbleiben. Daher wäre ein genetischer Marker, der mit dem Vernalisations-Locus assoziiert ist, vorteilhaft, um das rezessive Allel in einem Selektionsschritt zu entfernen. Um Marker zu identifizieren, die mit dem Vernalisations-Locus assoziiert sind, wurden Genotyping by Sequencing (GBS)-Daten zu 70 zweijährigen und 67 einjährigen Blühtypen genutzt. Case-Control-Studien und populationsgenetische Studien wurden durchgeführt. Insgesamt wurden 60 gemeinsame Marker gefunden, die signifikant mit dem Vernalisationsbedarf assoziiert waren. Für 19 Marker wurden diagnostische Marker entwickelt. Diese könnten in Zukunft genutzt werden, um rezessive Allele in segregierenden Populationen zu detektieren.Caraway (Carum carvi) can be divided into biennial and annual flowering types. Biennials require a cold stimulus for initiation of flowering, whereas annuals lack any vernalization requirement. Cultivation of annuals is considered advantageous due to better integration into crop rotation and reduced production costs. However, available annual varieties lack a sufficient yield potential and essential oil content. Valuable genetic diversity exists within the biennial genepool, which can be transferred to the annual genepool by crossbreeding. According to literature, F1 plants from crosses between annual and biennial flowering types uniformly show annual flowering. Resulting F2 populations show a Mendelian 3:1 ratio between annual and biennial flowering types. This indicates a monogenetic inheritance of vernalization requirement in caraway with dominant annual flowering. After crossbreeding annual and biennial flowering types, the recessive allele for biennial flowering can remain within the breeding material over multiple generations. Thus, a genetic marker associated with the vernalization locus would be beneficial to remove the recessive allele in one selection step. To identify markers associated with vernalization requirement, we used genotyping by sequencing (GBS) data of 70 biennial and 67 annual flowering types. We conducted case-control studies and population differentiation-based tests. In total, 60 common markers were found that were significantly associated with vernalization requirement. Out of these, we developed 19 diagnostic markers. In future, these diagnostic markers might be used to detect recessive alleles in segregating populations

    Adaptive synchronization in delay-coupled networks of Stuart-Landau oscillators

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    We consider networks of delay-coupled Stuart-Landau oscillators. In these systems, the coupling phase has been found to be a crucial control parameter. By proper choice of this parameter one can switch between different synchronous oscillatory states of the network. Applying the speed-gradient method, we derive an adaptive algorithm for an automatic adjustment of the coupling phase such that a desired state can be selected from an otherwise multistable regime. We propose goal functions based on both the difference of the oscillators and a generalized order parameter and demonstrate that the speed-gradient method allows one to find appropriate coupling phases with which different states of synchronization, e.g., in-phase oscillation, splay or various cluster states, can be selected.Comment: 8 pages, 7 figure

    Nonequilibrium Josephson-like effects in wide mesoscopic S-N-S junctions

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    Mesoscopic superconducting-normal-metal-superconducting (S-N-S) junctions with a large separation between the superconducting electrodes (i.e. wide junctions) exhibit nonequilibrium supercurrents, even at temperatures for which the equilibrium Josephson effect is exponentially small. The second harmonic of the Josephson frequency dominates these currents, as observed in recent experiments. A simple description of these effects, in the spirit of the Resistively-Shunted-Junction model, is suggested here. It is used to calculate dc I-V characteristics, and to examine the effects of various types of noise and of external microwave radiation (Shapiro steps). It is found that the nonequilibrium supercurrents are excited when the junction is driven by a dc bias or an ac bias, or even by external noise. In the case of junctions which are also long in the direction perpendicular to the current flow, thermodynamic phase fluctuations (thermal noise) alone can drive the quasiparticles out of local equilibrium. Magnetic flux is then predicted to be trapped in units of Phi_0 /2 = hc/4e.Comment: 10 pages, to appear in a special issue of Superlattices & Microstructure

    Income-, education- and gender-related inequalities in out-of-pocket health-care payments for 65+ patients - a systematic review

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    BACKGROUND: In all OECD countries, there is a trend to increasing patients' copayments in order to balance rising overall health-care costs. This systematic review focuses on inequalities concerning the amount of out-of-pocket payments (OOPP) associated with income, education or gender in the Elderly aged 65+. METHODS: Based on an online search (PubMed), 29 studies providing information on OOPP of 65+ beneficiaries in relation to income, education and gender were reviewed. RESULTS: Low-income individuals pay the highest OOPP in relation to their earnings. Prescription drugs account for the biggest share. A lower educational level is associated with higher OOPP for prescription drugs and a higher probability of insufficient insurance protection. Generally, women face higher OOPP due to their lower income and lower labour participation rate, as well as less employer-sponsored health-care. CONCLUSIONS: While most studies found educational and gender inequalities to be associated with income, there might also be effects induced solely by education; for example, an unhealthy lifestyle leading to higher payments for lower-educated people, or exclusively gender-induced effects, like sex-specific illnesses. Based on the considered studies, an explanation for inequalities in OOPP by these factors remains ambiguous
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