| 1. |
- Demczuk, Walter, et al.
(author)
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Genomic epidemiology and molecular resistance mechanisms of azithromycin resistant Neisseria gonorrhoeae in Canada from 1997 to 2014
- 2016
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In: Journal of Clinical Microbiology. - Washington, USA : American Society for Microbiology. - 0095-1137 .- 1098-660X. ; 54:5, s. 1304-1313
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Journal article (peer-reviewed)abstract
- The emergence of Neisseria gonorrhoeae with decreased susceptibility to cephalosporins and azithromycin resistance (AZM-R) represent a public health threat of untreatable gonorrhoea infections. Genomic epidemiology through whole genome sequencing was used to describe the emergence, dissemination, and spread of AZM-R strains. The genomes of 213 AZM-R and 23 AZM-susceptible N. gonorrhoeae isolates collected in Canada from 1989 to 2014 were sequenced. Core single nucleotide polymorphism (SNP) phylogenomic analysis resolved 246 isolates into 13 lineages. High-level AZM-R (minimum inhibitory concentration ≥256 μg/ml) was found in 5 phylogenetically diverse isolates, all of which possessed the A2059G mutation (Escherichia coli numbering) in all four 23S rRNA alleles. One high-level AZM-R isolate collected in 2009 concurrently had decreased susceptibility to ceftriaxone (MIC=0.125 μg/ml). An increase in the number of 23S rRNA alleles with the C2611T mutations (E. coli numbering) conferred low to moderate AZM-R (2 to 4 and 8 to 32 μg/mL, respectively). Low level AZM-R was also associated with mtrR promoter mutations including -35A deletion and the presence of N. meningitidis-like sequences. Geographic and temporal phylogenetic clustering indicate emergent AZM-R strains arise independently and can then rapidly expand clonally in a region through local sexual networks.
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| 2. |
- Graham, Angus, 1968-, et al.
(author)
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Theban Harbours and Waterscapes Survey, 2014
- 2015
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In: Journal of Egyptian Archaeology. - London : Egypt Exploration Society. - 0307-5133. ; 100, s. 41-53
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Journal article (peer-reviewed)
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| 3. |
- Graham, Angus, 1968-, et al.
(author)
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Theban Harbours and Waterscapes Survey, 2015
- 2015
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In: Journal of Egyptian Archaeology. - : SAGE Publications. - 0307-5133 .- 2514-0582. ; 101:1, s. 37-49
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Journal article (peer-reviewed)abstract
- Report on the 2015 season of the Theban Harbours and Waterscapes Survey (THaWS). The paper discusses the extension of geoarchaeological and geophysical investigations to the east of the Ramesseum, the continuing work in and around the Temple of Millions of Years of Amenhotep III, and the topographic survey and geophysical survey of the western mounds of the Birket Habu.
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| 4. |
- Irani, Ido, et al.
(author)
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SN 2022oqm-A Ca-rich Explosion of a Compact Progenitor Embedded in C/O Circumstellar Material
- 2024
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In: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 962:2
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Journal article (peer-reviewed)abstract
- We present the discovery and analysis of SN 2022oqm, a Type Ic supernova (SN) detected <1 day after the explosion. The SN rises to a blue and short-lived (2 days) initial peak. Early-time spectral observations of SN 2022oqm show a hot (40,000 K) continuum with high ionization C and O absorption features at velocities of 4000 km s−1, while its photospheric radius expands at 20,000 km s−1, indicating a pre-existing distribution of expanding C/O material. After ∼2.5 days, both the spectrum and light curves evolve into those of a typical SN Ic, with line velocities of ∼10,000 km s−1, in agreement with the evolution of the photospheric radius. The optical light curves reach a second peak at t ≈ 15 days. By t = 60 days, the spectrum of SN 2022oqm becomes nearly nebular, displaying strong Ca ii and [Ca ii] emission with no detectable [O i], marking this event as Ca-rich. The early behavior can be explained by 10−3M⊙ of optically thin circumstellar material (CSM) surrounding either (1) a massive compact progenitor such as a Wolf–Rayet star, (2) a massive stripped progenitor with an extended envelope, or (3) a binary system with a white dwarf. We propose that the early-time light curve is powered by both the interaction of the ejecta with the optically thin CSM and shock cooling (in the massive star scenario). The observations can be explained by CSM that is optically thick to X-ray photons, is optically thick in the lines as seen in the spectra, and is optically thin to visible-light continuum photons that come either from downscattered X-rays or from the shock-heated ejecta. Calculations show that this scenario is self-consistent.
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| 5. |
- Soumagnac, Maayane T., et al.
(author)
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SN 2018fif : The Explosion of a Large Red Supergiant Discovered in Its Infancy by the Zwicky Transient Facility
- 2020
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In: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 902:1
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Journal article (peer-reviewed)abstract
- High-cadence transient surveys are able to capture supernovae closer to their first light than ever before. Applying analytical models to such early emission, we can constrain the progenitor stars' properties. In this paper, we present observations of SN 2018fif (ZTF 18abokyfk). The supernova was discovered close to first light and monitored by the Zwicky Transient Facility (ZTF) and the Neil Gehrels Swift Observatory. Early spectroscopic observations suggest that the progenitor of SN 2018fif was surrounded by relatively small amounts of circumstellar material compared to all previous cases. This particularity, coupled with the high-cadence multiple-band coverage, makes it a good candidate to investigate using shock-cooling models. We employ the SOPRANOS code, an implementation of the model by Sapir & Waxman and its extension to early times by Morag et al. Compared with previous implementations, SOPRANOS has the advantage of including a careful account of the limited temporal validity domain of the shock-cooling model as well as allowing usage of the entirety of the early UV data. We find that the progenitor of SN 2018fif was a large red supergiant with a radius of R = 744.0(-128.0)(+183.0) R-circle dot and an ejected mass of M-ej = 9.3(-5.8)(+0.4) M-circle dot. Our model also gives information on the explosion epoch, the progenitor's inner structure, the shock velocity, and the extinction. The distribution of radii is double-peaked, with smaller radii corresponding to lower values of the extinction, earlier recombination times, and a better match to the early UV data. If these correlations persist in future objects, denser spectroscopic monitoring constraining the time of recombination, as well as accurate UV observations (e.g., with ULTRASAT), will help break the extinction/radius degeneracy and independently determine both.
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| 6. |
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| 7. |
- Toonen, Willem H. J., et al.
(author)
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Holocene fluvial history of the Nile's west bank at ancient Thebes, Luxor, Egypt, and its relation with cultural dynamics and basin-wide hydroclimatic variability
- 2018
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In: Geoarchaeology. - : WILEY. - 0883-6353 .- 1520-6548. ; 33:3, s. 273-290
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Journal article (peer-reviewed)abstract
- In the Theban area around modern Luxor (Egypt), the River Nile divides the temple complexes of Karnak and Luxor from New Kingdom royal cult temples on the western desert edge. Few sites have been archaeologically identified in the western flood plain, despite its presumed pivotal role in the ancient ritual landscape as the territory that both physically divided and symbolically connected the areas inhabited by the living and the areas occupied by the dead. Using borehole data and electrical resistivity tomography, the current investigation of subsurface deposits reveals the location of an abandoned channel of the Nile. This river course was positioned in the western, distal part of the Nile flood plain. Over 2100 ceramic fragments recovered from boreholes date the abandonment of the relatively minor river channel to the (late) New Kingdom. This minor river branch could have played an important role in the cultural landscape, as it would have served to connect important localities in the ritual landscape. Changes in the fluvial landscape match with established periods of basin-wide hydroclimatic variability. This links cultural and landscape changes observed on a regional scale to hydroclimatic dynamics in the larger Nile catchment, in one of the focal areas of Ancient Egyptian cultural development.
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