Sommerfeld enhancement from Goldstone pseudo-scalar exchange

We point out that the exchange of a Goldstone pseudo-scalar can provide an enhancement in the dark matter annihilation rate capable of explaining the excess flux seen in high energy cosmic ray data. The mechanism of enhancement involves the coupling of s and d waves through the tensor force that is very strong and, in fact, singular at short distances. The results indicate that large enhancements require some amount of fine tuning. We also discuss the enhancement due to other singular attractive potentials, such as WIMP models with a permanent electric dipole.Comment: 14 pages, 4 figures, v2 includes contact informatio

Resolving the phylogenetic and taxonomic status of dark-spored teleomorph genera in the Botryosphaeriaceae

Species in the Botryosphaeriaceae are common plant pathogens and saprobes found on a variety of mainly woody hosts. Teleomorphs typically have hyaline, aseptate ascospores. However, some have been reported with brown ascospores and their taxonomic status is uncertain. A multi-gene approach (SSU, ITS, LSU, EF1-α and β-tubulin) was used to resolve the correct phylogenetic position of the dark-spored ‘Botryosphaeria’ teleomorphs and related asexual species. Neodeightonia and Phaeobotryon are reinstated for species with brown ascospores that are either 1-septate (Neodeightonia) or 2-septate (Phaeobotryon). Phaeobotryosphaeria is reinstated for species with brown, aseptate ascospores that bear an apiculus at either end. The status of Sphaeropsis is clarified and shown to be the anamorph of Phaeobotryosphaeria. Two new genera, namely Barriopsis for species having brown, aseptate ascospores without apiculi and Spencermartinsia for species having brown, 1-septate ascospores with an apiculus at either end are introduced. Species of Dothiorella have brown, 1-septate ascospores and differ from Spencermartinsia in the absence of apiculi. These six genera can also be distinguished from one another based on morphological characters of their anamorphs. Although previously placed in the Botryosphaeriaceae, Dothidotthia, was shown to belong in the Pleosporales, and the new family Dothidotthiaceae is introduced to accommodate it

Efficiency of free energy calculations of spin lattices by spectral quantum algorithms

Quantum algorithms are well-suited to calculate estimates of the energy spectra for spin lattice systems. These algorithms are based on the efficient calculation of the discrete Fourier components of the density of states. The efficiency of these algorithms in calculating the free energy per spin of general spin lattices to bounded error is examined. We find that the number of Fourier components required to bound the error in the free energy due to the broadening of the density of states scales polynomially with the number of spins in the lattice. However, the precision with which the Fourier components must be calculated is found to be an exponential function of the system size.Comment: 9 pages, 4 figures; corrected typographical and minor mathematical error

Polaron formation for a non-local electron-phonon coupling: A variational wave-function study

We introduce a variational wave-function to study the polaron formation when the electronic transfer integral depends on the relative displacement between nearest-neighbor sites giving rise to a non-local electron-phonon coupling with optical phonon modes. We analyze the ground state properties such as the energy, the electron-lattice correlation function, the phonon number and the spectral weight. Variational results are found in good agreement with analytic weak-coupling perturbative calculations and exact numerical diagonalization of small clusters. We determine the polaronic phase diagram and we find that the tendency towards strong localization is hindered from the pathological sign change of the effective next-nearest-neighbor hopping.Comment: 11 page

New insights into the antimicrobial action of cinnamaldehyde towards escherichia coli and its effects on intestinal colonization of mice

Escherichia coli is responsible for cases of diarrhea around the world, and some studies have shown the benefits of cinnamaldehyde in the treatment of bacterial disease. Therefore, the objective of this study was to evaluate the effects of cinnamaldehyde in mice colonized by pathogenic E. coli, as well as to provide more insights into its antimicrobial action mechanism. After determination of minimum inhibitory (MIC) and minimum bactericidal (MBC) concentrations, the interference of cinnamaldehyde in macromolecular pathways (synthesis of DNA, RNA, protein, and cell wall) was measured by incorporation of radioisotopes. The anti-adhesive properties of cinnamaldehyde towards E. coli 042 were evaluated using human epithelial type 2 (HEp-2) cells. Intestinal colonization was tested on mice, and the effect of cinnamaldehyde on Tenebrio molitor larvae. Cinnamaldehyde showed MIC and MBC values of 780 μg/mL and 1560 μg/mL, respectively; reduced the adhesion of E. coli 042 on HEp-2 cells; and affected all the synthetic pathways evaluated, suggesting that compost impairs the membrane/cell wall structure leading bacteria to total collapse. No effect on the expression of genes related to the SOS pathway (sulA and dinB1) was observed. The compound did not interfere with cell viability and was not toxic against T. molitor larvae. In addition, cinnamaldehyde-treated mice exhibited lower levels of colonization by E. coli 042 than the untreated group. Therefore, the results show that cinnamaldehyde is effective in treating the pathogenic E. coli strain 042 and confirm it as a promising lead molecule for the development of antimicrobial agents

Implementation and first results of the KM3NeT real-time core-collapse supernova neutrino search

The KM3NeT research infrastructure is unconstruction in the Mediterranean Sea. KM3NeT will study atmospheric and astrophysical neutrinos with two multi-purpose neutrino detectors, ARCA and ORCA, primarily aimed at GeV–PeV neutrinos. Thanks to the multi-photomultiplier tube design of the digital optical modules, KM3NeT is capable of detecting the neutrino burst from a Galactic or near-Galactic core-collapse supernova. This potential is already exploitable with the first detection units deployed in the sea. This paper describes the real-time implementation of the supernova neutrino search, operating on the two KM3NeT detectors since the first months of 2019. A quasi-online astronomy analysis is introduced to study the time profile of the detected neutrinos for especially significant events. The mechanism of generation and distribution of alerts, as well as the integration into the SNEWS and SNEWS 2.0 global alert systems, are described. The approach for the follow-up of external alerts with a search for a neutrino excess in the archival data is defined. Finally, an overview of the current detector capabilities and a report after the first two years of operation are given.Acknowledgements The authors acknowledge the financial support of the funding agencies: Agence Nationale de la Recherche (contract ANR-15-CE31-0020), Centre National de la Recherche Scientifique (CNRS), Commission Européenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), LabEx UnivEarthS (ANR-10-LABX-0023 and ANR-18-IDEX-0001), Paris Île-de-France Region, France; Shota Rustaveli National Science Foundation of Georgia (SRNSFG, FR-18-1268), Georgia; Deutsche Forschungsgemeinschaft (DFG), Germany; The General Secretariat of Research and Technology (GSRT), Greece; Istituto Nazionale di Fisica Nucleare (INFN), Ministero dell’Università e della Ricerca (MIUR), PRIN 2017 program (Grant NAT-NET 2017W4HA7S) Italy; Ministry of Higher Education Scientific Research and Professional Training, ICTP through Grant AF-13, Morocco; Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; The National Science Centre, Poland (2015/18/E/ST2/00758); National Authority for Scientific Research (ANCS), Romania; Ministerio de Ciencia, Innovación, Investigación y Universidades (MCIU): Programa Estatal de Generación de Conocimiento (refs. PGC2018-096663-B-C41, -A-C42, -B-C43, -B-C44) (MCIU/FEDER), Generalitat Valenciana: Prometeo (PROMETEO/2020/019), Grisolía (ref. GRISOLIA/2018/119) and GenT (refs. CIDEGENT/2018/034, /2019/043, /2020/049) programs, Junta de Andalucía (ref. A-FQM-053-UGR18), La Caixa Foundation (ref. LCF/BQ/IN17/11620019), EU: MSC program (ref. 101025085), Spain