1. |
- Abercrombie, Daniel, et al.
(författare)
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Dark Matter benchmark models for early LHC Run-2 Searches : Report of the ATLAS/CMS Dark Matter Forum
- 2020
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Ingår i: Physics of the Dark Universe. - : Elsevier BV. - 2212-6864. ; 27
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Tidskriftsartikel (refereegranskat)abstract
- This document is the final report of the ATLAS-CMS Dark Matter Forum, a forum organized by the ATLAS and CMS collaborations with the participation of experts on theories of Dark Matter, to select a minimal basis set of dark matter simplified models that should support the design of the early LHC Run-2 searches. A prioritized, compact set of benchmark models is proposed, accompanied by studies of the parameter space of these models and a repository of generator implementations. This report also addresses how to apply the Effective Field Theory formalism for collider searches and present the results of such interpretations.
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2. |
- Bondad-Reantaso, Melba G., et al.
(författare)
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Review of alternatives to antibiotic use in aquaculture
- 2023
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Ingår i: Reviews in Aquaculture. - : John Wiley & Sons. - 1753-5123 .- 1753-5131. ; 15:4, s. 1421-1451
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Forskningsöversikt (refereegranskat)abstract
- With the rapid growth of the aquaculture production since the 1980s, there has been a concomitant increase in disease outbreaks. The injudicious and/or incorrect use of antimicrobial agents against diseases of farmed aquatic species poses a considerable threat to the development and growth of a successful and sustainable aquaculture industry. An increase in antimicrobial resistance (AMR) is an important consequence, resulting to the difficulty in treating common bacterial diseases in populations of aquatic organisms, combined with the presence of antibiotic residues in food fish and their products, leading to import refusals and negative impacts on international trade. To reduce the frequency of AMR, good aquaculture and effective biosecurity practices should include the prudent and responsible use of antibiotics and also consider the use of alternatives to antibiotics, in addition to disease prevention management. This article reviews the literature discussing the scope of the problem pertaining to antibiotic use, the emergence of AMR in aquaculture and to consider and discuss viable alternatives (e.g., vaccination, bacteriophages, quorum quenching, probiotics and prebiotics, chicken egg yolk antibody and medicinal plant derivative). We also discuss lessons learnt, from specific case studies such as the vaccination of farmed salmon in Norway and the use of 'specific pathogen-free' seed-as primary and essential part of a biosecurity strategy.
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3. |
- Aad, G, et al.
(författare)
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- 2015
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swepub:Mat__t
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4. |
- Ackermann, M., et al.
(författare)
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The Fermi Galactic Center GeV Excess and Implications for Dark Matter
- 2017
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Ingår i: Astrophysical Journal. - : Institute of Physics Publishing. - 0004-637X .- 1538-4357. ; 840:1
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Tidskriftsartikel (refereegranskat)abstract
- The region around the Galactic Center (GC) is now well established to be brighter at energies of a few GeV than what is expected from conventional models of diffuse gamma-ray emission and catalogs of known gamma-ray sources. We study the GeV excess using 6.5 yr of data from the Fermi Large Area Telescope. We characterize the uncertainty of the GC excess spectrum and morphology due to uncertainties in cosmic-ray source distributions and propagation, uncertainties in the distribution of interstellar gas in the Milky Way, and uncertainties due to a potential contribution from the Fermi bubbles. We also evaluate uncertainties in the excess properties due to resolved point sources of gamma rays. The GC is of particular interest, as it would be expected to have the brightest signal from annihilation of weakly interacting massive dark matter (DM) particles. However, control regions along the Galactic plane, where a DM signal is not expected, show excesses of similar amplitude relative to the local background. Based on the magnitude of the systematic uncertainties, we conservatively report upper limits for the annihilation cross-section as a function of particle mass and annihilation channel.
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5. |
- Caputo, Andrea, et al.
(författare)
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A short comparison of two marine planktonic diazotrophic symbioses highlights an un-quantified disparity
- 2018
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Ingår i: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Some N2-fixing cyanobacteria form symbiosis with diverse protists. In the plankton two groups of diazotrophic symbioses are described: (1) a collective group of diatoms which associate with heterocystous cyanobacteria (Diatom Diazotroph Associations, DDA), and (2) the microalgal prymnesiophyte Braarudosphaera bigelowii and its relatives which associate with the unicellular cyanobacterium Candidatus Atelocyanobacterium thalassa (hereafter as UCYN-A). Both symbiotic systems co-occur, and in both partnerships the symbionts function as a nitrogen (N) source. In this perspective, we provide a brief comparison between the DDAs and the prymnesiophyte-UCYN-A symbioses highlighting similarities and differences in both systems, and present a bias in the attention and current methodology that has led to an under-detection and under-estimation of the DDAs.
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6. |
- Caputo, Andrea, et al.
(författare)
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Antimicrobial resistance in aquaculture : A global analysis of literature and national action plans
- 2023
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Ingår i: Reviews in Aquaculture. - : John Wiley & Sons. - 1753-5123 .- 1753-5131. ; 15:2, s. 568-578
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Forskningsöversikt (refereegranskat)abstract
- Since the establishment of a Global Action Plan (GAP) on Antimicrobial Resistance (AMR) (68th World Health Assembly, Geneva, Switzerland, 2015), most members of the World Health Organisation (WHO) have developed and implemented a National Action Plan (NAP) based on a "One Health" approach to AMR. Aquaculture, significant among the food producing sectors, has often been overlooked in AMR governance. We did a systematic review of 95 country NAPs and assessed the inclusion of aquaculture. We also reviewed the scientific literature from 1996 until April 2021 to retrieve data characterising AMR in aquaculture during the last 25 years. In our analysis, 37% of countries did not mention an aquaculture component within their AMR NAP. The South-East Asia Region had the highest implementation rate of AMR-aquaculture programmes. Our literature review indicated that most AMR-aquaculture related studies have taken place in China, followed by the United States of America and India. Beta-lactamases, tetracyclines, sulfonamides, macrolides, and fluoroquinolones were the most represented classes of antibiotics, with Vibrio spp. and Aeromonas spp. as the most investigated antimicrobial-resistant bacteria. This review highlighted the gaps in AMR-aquaculture governance and the progress made across WHO members. Countries are encouraged to (i) fulfil their commitments by developing and/or fully implementing the AMR NAP, (ii) further engage in the research, monitoring, and surveillance of antimicrobial usage and AMR within the aquaculture sector, and (iii) collaborate at national and international level for a concerted "One Health" approach.
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7. |
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8. |
- Caputo, Andrea, et al.
(författare)
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Dark photon limits : A handbook
- 2021
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Ingår i: Physical Review D. - : American Physical Society (APS). - 2470-0010 .- 2470-0029. ; 104:9
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Tidskriftsartikel (refereegranskat)abstract
- The dark photon is a massive hypothetical particle that interacts with the Standard Model by kinetically mixing with the visible photon. For small values of the mixing parameter, dark photons can evade cosmological bounds to be a viable dark matter candidate. Due to the similarities with the electromagnetic signals generated by axions, several bounds on dark photon signals are simply reinterpretations of historical bounds set by axion haloscopes. However, the dark photon has a property that the axion does not: an intrinsic polarization. Due to the rotation of the Earth, accurately accounting for this polarization is nontrivial, highly experiment dependent, and depends upon assumptions about the dark photon's production mechanism. We show that if one does account for the dark photon polarization, and the rotation of the Earth, an experiment's discovery reach can be enhanced by over an order of magnitude. We detail the strategies that would need to be taken to properly optimize a dark photon search. These include judiciously choosing the location and orientation of the experiment, as well as strategically timing any repeated measurements. Experiments located at 135 degrees or 155 degrees latitude, making three observations at different times of the sidereal day, can achieve a sensitivity that is fully optimized and insensitive to the dark photon's polarization state, and hence its production mechanism. We also point out that several well-known searches for axions employ techniques for testing signals that preclude their ability to set exclusion limits on dark photons, and hence should not be reinterpreted as such.
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9. |
- Caputo, Andrea, 1988-
(författare)
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Genomic and morphological diversity of marine planktonic diatom-diazotroph associations : a continuum of integration and diversification through geological time
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Symbioses between eukaryotes and nitrogen (N2)-fixing cyanobacteria (or diazotrophs) are quite common in the plankton community. A few genera of diatoms (Bacillariophyceae) such as Rhizosolenia, Hemiaulus and Chaetoceros are well known to form symbioses with the heterocystous diazotrophic cyanobacteria Richelia intracellularis and Calothrix rhizosoleniae. The latter are also called diatom-diazotroph associations, or DDAs. Up to now, the prokaryotic partners have been morphologically and genetically characterized, and the phylogenetic reconstruction of the well conserved nifH gene (encodes for the nitrogenase enzyme) placed the symbionts in 3 clusters based on their host-specificity, i.e. het-1 (Rhizosolenia-R. intracellularis), het-2 (Hemiaulus-R. intracellularis), and het-3 (Chaetoceros-C- rhizosoleniae). Conversely, the diatom-hosts, major representative of the phytoplankton community and crucial contributors to the carbon (C) biogeochemical cycle, have been understudied.The first aim of this thesis was to genetically and morphologically characterize the diatom-hosts, and to reconstruct the evolutionary background of the partnerships and the symbiont integration in the host. The molecular-clock analysis reconstruction showed the ancient appearance of the DDAs, and the traits characterizing the ancestors. In addition, diatom-hosts bearing internal symbionts (with more eroded draft genomes) appeared earlier than diatom-hosts with external symbionts. Finally a blast survey highlighted a broader distribution of the DDAs than expected.The second aim of this thesis was to compare genetic and physiological characteristics of the DDAs symbionts with the other eukaryote-diazotroph symbiosis, i.e. prymnesiophyte-UCYN-A (or Candidatus Atelocyanobacterium thalassa). The genome comparison highlighted more genes for transporters in het-3 (external symbiont) and in the UCYN-A based symbiosis, suggesting that symbiont location might be relevant also for metabolic exchanges and interactions with the host and/or environment. Moreover, a summary of methodological biases that brought to an underestimation of the DDAs is reported.The third aim of this thesis was to determine the distribution of the DDAs in the South Pacific Ocean using a quantitative polymerase chain reaction (qPCR) approach and to outline the environmental drivers of such distribution. Among the het-groups, het-1 was the most abundant/detected and co-occurred with the other 2 symbiotic strains, all responding similarly to the influence of abiotic factors, such as temperature and salinity (positive and negative correlation, respectively). Globally, Trichodesmium dominated the qPCR detections, followed by UCYN-B. UCYN-A phylotypes (A-1, A-2) were detected without their proposed hosts, for which new oligonucleotides were designed. The latter suggested a facultative symbiosis. Finally, microscopy observations of the het-groups highlighted a discrepancy with the qPCR counts (i.e. the former were several order of magnitudes lower), leading to the idea of developing a new approach to quantify the DDAs. The fourth aim of this thesis was to develop highly specific in situ hybridization assays (CARD-FISH) to determine the presence of alternative life-stages and/or free-living partners. The new assays were applied to samples collected in the South China Sea and compared with abundance estimates from qPCR assays for the 3 symbiotic strains. Free-living cells were indeed detected along the transect, mainly at deeper depths. Free-living symbionts had two morphotypes: trichomes and single-cells. The latter were interpreted as temporary life-stages. Consistent co-occurrence of the 3 het-groups was also found in the SCS and application of a SEM model predicted positive interactions between the het groups. We interpreted the positive interaction as absence of intra-specific competition, and consistent with the previous study, temperature and salinity were predicted as major drivers of the DDAs distribution.
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10. |
- Caputo, Andrea, et al.
(författare)
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Revisiting longitudinal plasmon-axion conversion in external magnetic fields
- 2020
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Ingår i: Physical Review D. - : American Physical Society (APS). - 1550-7998 .- 1550-2368. ; 101:12
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Tidskriftsartikel (refereegranskat)abstract
- In the presence of an external magnetic field, the axion and the photon mix. In particular, the dispersion relation of a longitudinal plasmon always crosses the dispersion relation of the axion (for small axion masses), thus leading to a resonant conversion. Using thermal field theory, we concisely derive the axion emission rate, applying it to astrophysical and laboratory scenarios. For the Sun, depending on the magnetic field profile, plasmon-axion conversion can dominate over Primakoff production at low energies (less than or similar to 200 eV). This both provides a new axion source for future helioscopes and, in the event of discovery, would probe the magnetic field structure of the Sun. In the case of white dwarfs (WDs), plasmon-axion conversion provides a pure photon coupling probe of the axion, which may contribute significantly for low-mass WDs. Finally, we rederive and confirm the axion absorption rate of the recently proposed plasma haloscopes.
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