23 research outputs found

    Momentum-dependent contributions to the gravitational coupling of neutrinos in a medium

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    When neutrinos travel through a normal matter medium, the electron neutrinos couple differently to gravity compared to the other neutrinos, due to the presence of electrons in the medium and the absence of the other charged leptons. We calculate the momentum-dependent part of the matter-induced gravitational couplings of the neutrinos under such conditions, which arise at order g2/MW4g^2/M^4_W, and determine their contribution to the neutrino dispersion relation in the presence of a gravitational potential Ď•ext\phi^{\mathrm{ext}}. These new contributions vanish for the muon and tau neutrinos. For electron neutrinos with momentum KK, they are of the order of the usual Wolfenstein term times the factor (K2/MW2)Ď•ext(K^2/M^2_W)\phi^{\mathrm{ext}}, for high energy neutrinos. In environments where the gravitational potential is substantial, such as those in the vicinity of Active Galactic Nuclei, they could be the dominant term in the neutrino dispersion relation. They must also be taken into account in the analysis of possible violations of the Equivalence Principle in the neutrino sector, in experimental settings involving high energy neutrinos traveling through a matter background.Comment: Minor corrections in the references; one reference adde

    Some Remarks on the Neutrino Oscillation Phase in a Gravitational Field

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    The weak gravitational field expansion method to account for the gravitationally induced neutrino oscillation effect is critically examined. It is shown that the splitting of the neutrino phase into a ``kinematic'' and a ``gravitational'' phase is not always possible because the relativistic factor modifies the particle interference phase splitting condition in a gravitational field.Comment: 4 pages, no figure

    Critical Behavior of Dimensionally Continued Black Holes

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    The critical behavior of black holes in even and odd dimensional spacetimes is studied based on Ba\~nados-Teitelboim-Zanelli (BTZ) dimensionally continued black holes. In even dimensions it is found that asymptotically flat and anti de-Sitter Reissner-Nordstr\"om black holes present up to two second order phase transitions. The case of asymptotically anti-de-Sitter Schwarzschild black holes present only one critical transition and a minimum of temperature, which occurs at the transition. Finally, it is shown that phase transitions are absent in odd dimensions.Comment: 21 pages in Latex format, no figures, vastly improved version to appear in Phys. Rev.

    The general treatment of high/low energy particle interference phase in a gravitational field

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    The interference phase of the high energy mass neutrinos and the low energy thermal neutrons in a gravitational field are studied. For the mass neutrinos, we obtain that the phase calculated along the null is equivalent to the half phase along the geodesic in the high energy limit, which means that the correct relative phase of the mass neutrinos is either the null phase or the half geodesic phase. Further we point out the importance of the energy condition in calculating the mass neutrino interference phase. Moreover, we apply the covariant phase to the calculation of the thermal neutron interference phase, and obtain the consistent result with that exploited in COW experiment.Comment: 14 pages, 1 figur

    Neutrino spin-flips in curved space-time

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    The general relativistic effects on spin-flavor oscillations above the core of type II supernovae are investigated. The evolution equation is derived and the relative magnitudes of the terms in the Hamiltonian, which arise from the weak, electromagnetic and gravitational interaction, are compared. The effects on the resonance position and the adiabaticity are studied. Explicit calculations are presented for non-rotating and slowly rotating stars.Comment: 16 pages, 1 figure, accepted by Phys. Rev.

    Neutrino oscillations in curved spacetime: an heuristic treatment

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    We discuss neutrino oscillations in curved spacetime. Our heuristic approach can accomodate matter effects and gravitational contributions to neutrino spin precession in the presence of a magnetic field. By way of illustration, we perform explicit calculations in the Schwarzschild geometry. In this case, gravitational effects on neutrino oscillations are intimately related to the redshift. We discuss how spacetime curvature could affect the resonance position and adiabaticity of matter-enhanced neutrino flavor conversion.Comment: 7 pages, REVTeX and 1 included style file. Submitted to Phys. Rev.

    Interplay of Non-Relativistic and Relativistic Effects in Neutrino Oscillations

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    A theoretical structure that involves neutrino mass eigenstates at non relativistic as well as relativistic energies is presented. Using this framework, we find that if the particle X, with mass 33.9 MeV, of the KARMEN collaboration anomaly is identified with the third neutrino mass eigenstate, then the present limit of 23 MeV upper bound on the tau neutrino mass implies |U_{\tau 3}| < 0.82.Comment: Revtex 3.0, 12 page

    Rapid, efficient auxin-inducible protein degradation in Candida pathogens

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    A variety of inducible protein degradation (IPD) systems have been developed as powerful tools for protein functional characterization. IPD systems provide a convenient mechanism for rapid inactivation of almost any target protein of interest. Auxin-inducible degradation (AID) is one of the most common IPD systems and has been established in diverse eukaryotic research model organisms. Thus far, IPD tools have not been developed for use in pathogenic fungal species. Here, we demonstrate that the original AID and the second generation, AID2, systems work efficiently and rapidly in the human pathogenic yeasts, Candida albicans and Candida glabrata. We developed a collection of plasmids that support AID system use in laboratory strains of these pathogens. These systems can induce >95% degradation of target proteins within minutes. In the case of AID2, maximal degradation was achieved at low nanomolar concentrations of the synthetic auxin analog 5-adamantyl-indole-3-acetic acid. Auxin-induced target degradation successfully phenocopied gene deletions in both species. The system should be readily adaptable to other fungal species and to clinical pathogen strains. Our results define the AID system as a powerful and convenient functional genomics tool for protein characterization in fungal pathogens. IMPORTANCE Life-threatening fungal infections are an escalating human health problem, complicated by limited treatment options and the evolution of drug resistant pathogen strains. Identification of new targets for therapeutics to combat invasive fungal infections, including those caused by Candida species, is an urgent need. In this report, we establish and validate an inducible protein degradation methodology in Candida albicans and Candida glabrata that provides a new tool for protein functional characterization in these, and likely other, fungal pathogen species. We expect this tool will ultimately be useful for the identification and characterization of promising drug targets and factors involved in virulence and drug resistance.SDB is supported by grant AI136995, WSM-R by grant AI152494, and MCH, SDB, and JC-B by grant AI168050 from the National Institutes of Health, National Institute of Allergy and Infectious Diseases. JBG was also supported by the National Institute of Allergy and Infectious Diseases under award number T32AI148103. The content is solely the responsibility of the authors and does not necessarily represent the official view of the National Institutes of Health. The work was supported by the Indiana Clinical and Translational Sciences Institute funded in part by Award Number UL1TR002529 from the National Institutes of Health, National Center for Advancing Translational Sciences, Clinical and Translational Sciences Award. The authors gratefully acknowledge the support for the Purdue Genomics Facility via the Purdue Institute for Cancer Research, NIH grant P30 CA023168. MCH and SDB were supported by an award from the Purdue University AgSEED program. CRVA and JC-B are funded by project PID2020-118109RB-I00 from the Spanish MCIN/AEI/10.13039/501100011033 and by Internationalization Project “CL-EI-2021–08-IBFG Unit of Excellence” of the Spanish National Research Council (CSIC), funded by the Regional Government of Castile and Leon and co-financed by the European Regional Development Fund (ERDF “Europe drives our growth”).Peer reviewe

    What makes a cyanobacterial bloom disappear? A review of the abiotic and biotic cyanobacterial bloom loss factors

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    Cyanobacterial blooms present substantial challenges to managers and threaten ecological and public health. Although the majority of cyanobacterial bloom research and management focuses on factors that control bloom initiation, duration, toxicity, and geographical extent, relatively little research focuses on the role of loss processes in blooms and how these processes are regulated. Here, we define a loss process in terms of population dynamics as any process that removes cells from a population, thereby decelerating or reducing the development and extent of blooms. We review abiotic (e.g., hydraulic flushing and oxidative stress/UV light) and biotic factors (e.g., allelopathic compounds, infections, grazing, and resting cells/programmed cell death) known to govern bloom loss. We found that the dominant loss processes depend on several system specific factors including cyanobacterial genera-specific traits, in situ physicochemical conditions, and the microbial, phytoplankton, and consumer community composition. We also address loss processes in the context of bloom management and discuss perspectives and challenges in predicting how a changing climate may directly and indirectly affect loss processes on blooms. A deeper understanding of bloom loss processes and their underlying mechanisms may help to mitigate the negative consequences of cyanobacterial blooms and improve current management strategies
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