36 research outputs found

    The indigenous settlement of Monte Iato (western Sicily): an ethnoarchaeometric approach for outlining local Archaic ceramic productions

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    An ethnoarchaeometric approach has been followed to identify the textural and compositional characteristics of the ceramic pastes produced in ancient Iaitas/Ietas, an indigenous site located in western Sicily on Monte Iato, a few tens of kilometres from Palermo. This approach was primarily motivated by the lack of discovered Archaic kilns or production sites/workshops and the inability to identify reference groups. Raw clays were sampled in the territory of San Cipirello and San Giuseppe Iato (today\u2019s municipalities both sited on the northern slopes of Monte Iato), together with representative historic tiles and bricks locally produced until fairly recently. Grain-size analysis and experimental firings were performed on the clay samples. A significant number of archaeological ceramic samples (incised and painted indigenous pottery dating back to the seventh\u2013fifth centuries BCE) from stratigraphic excavations on Monte Iato, and hypothesized as local productions on a stylistic-morphological basis, was carefully selected for archaeometric analysis. This set of samples (90 in total, comprising raw clays, historic tiles/bricks and archaeological ceramics) underwent a combined chemical and mineralogical-petrographic analysis to identify any possible compositional matching. This approach enabled the identification of minero-petrographic and chemical markers pertinent to the indigenous Archaic pottery produced at Monte Iato, although no evidence of coeval ceramic kilns has been found so far. Local raw clay sources have been documented and some significant points of the cha\ueene op\ue9ratoire adopted in antiquity have been noted (clay mixing and tempering practices). Attesting Monte Iato as a centre of ceramic production and defining both the microscopic fabric and the average composition of local pastes open up new perspectives in the complex issue concerning the production and regional circulation of incised and painted indigenous ceramics in Archaic Sicily

    Cosmic histories of star formation and reionization: An analysis with a power-law approximation

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    With a simple power-law approximation of high-redshift (3.5\gtrsim3.5) star formation history, i.e., ρ˙(z)[(1+z)/4.5]α\dot{\rho}_*(z)\propto [(1+z)/4.5]^{-\alpha}, we investigate the reionization of intergalactic medium (IGM) and the consequent Thomson scattering optical depth for cosmic microwave background (CMB) photons. A constraint on the evolution index α\alpha is derived from the CMB optical depth measured by the {\it Wilkinson Microwave Anisotropy Probe} (WMAP) experiment, which reads α2.18lgNγ3.89\alpha\approx2.18\lg{\mathscr{N}_{\gamma}}-3.89, where the free parameter Nγ\mathscr{N}_\gamma is the number of the escaped ionizing ultraviolet photons per baryon. Moreover, the redshift for full reionization, zfz_f, can also be expressed as a function of α\alpha as well as Nγ\mathscr{N}_{\gamma}. By further taking into account the implication of the Gunn-Peterson trough observations to quasars for the full reionization redshift, i.e., 6zf76\lesssim z_f \lesssim7, we obtain 0.3α1.30.3\lesssim\alpha\lesssim1.3 and 80Nγ23080\lesssim\mathscr{N}_{\gamma}\lesssim230. For a typical number of 4000\sim4000 of ionizing photons released per baryon of normal stars, the fraction of these photons escaping from the stars, fescf_{\rm esc}, can be constrained to within the range of (2.05.8)(2.0-5.8)%.Comment: 10 pages, 4 figures, accepted for publication in JCA

    Phylogenomic analysis of a 55.1 kb 19-gene dataset resolves a monophyletic Fusarium that includes the Fusarium solani Species Complex

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    Scientific communication is facilitated by a data-driven, scientifically sound taxonomy that considers the end-user¿s needs and established successful practice. In 2013, the Fusarium community voiced near unanimous support for a concept of Fusarium that represented a clade comprising all agriculturally and clinically important Fusarium species, including the F. solani species complex (FSSC). Subsequently, this concept was challenged in 2015 by one research group who proposed dividing the genus Fusarium into seven genera, including the FSSC described as members of the genus Neocosmospora, with subsequent justification in 2018 based on claims that the 2013 concept of Fusarium is polyphyletic. Here, we test this claim and provide a phylogeny based on exonic nucleotide sequences of 19 orthologous protein-coding genes that strongly support the monophyly of Fusarium including the FSSC. We reassert the practical and scientific argument in support of a genus Fusarium that includes the FSSC and several other basal lineages, consistent with the longstanding use of this name among plant pathologists, medical mycologists, quarantine officials, regulatory agencies, students, and researchers with a stake in its taxonomy. In recognition of this monophyly, 40 species described as genus Neocosmospora were recombined in genus Fusarium, and nine others were renamed Fusarium. Here the global Fusarium community voices strong support for the inclusion of the FSSC in Fusarium, as it remains the best scientific, nomenclatural, and practical taxonomic option availabl

    Impact of Early Versus Delayed Atrial Fibrillation Catheter Ablation on Atrial Arrhythmia Recurrences

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    Online publish-ahead-of-print 16 April 2023Background: Catheter ablation is an effective strategy in atrial fibrillation (AF). However, its timing in the course of management remains unclear. The aim of this study was to determine if an early vs. delayed AF ablation strategy is associated with differences in arrhythmia outcomes during 12-month follow-up. Methods and results: One hundred patients with symptomatic AF referred to a tertiary centre for management were randomized in a 1:1 ratio to either an early ablation strategy (within 1 month of recruitment) or a delayed ablation strategy (optimized medical therapy followed by catheter ablation at 12 months post recruitment). The primary endpoint was atrial arrhythmia free survival at 12 months post-ablation. Secondary outcomes included: (i) AF burden, (ii) AF burden by AF phenotype, and (iii) antiarrhythmic drug (AAD) use at 12 months. Overall, 89 patients completed the study protocol (Early vs. Delayed: 48 vs. 41). Mean age was 59 ± 12.9 years (29% women). Pulmonary vein isolation was achieved in 100% of patients. At 12 months, 56.3% of patients in the early ablation group were free from recurrent arrhythmia, compared with 58.6% in the delayed ablation group (HR 1.12, 95% CI 0.59–2.13, P = 0.7). All secondary outcomes showed no significant difference including median AF burden (Early vs. Delayed: 0% [IQR 3.2] vs. 0% [5], P = 0.66), median AF burden amongst paroxysmal AF patients (0% [IQR 1.1] vs. 0% [4.5], P = 0.78), or persistent AF patients (0% [IQR 22.8] vs. 0% [5.6], P = 0.45) or AAD use (33% vs. 37%, P = 0.8). Conclusion: Compared with an early ablation strategy, delaying AF ablation by 12 months for AAD management did not result in reduced ablation efficacy.Jonathan M. Kalman, Ahmed M. Al-Kaisey, Ramanathan Parameswaran, Joshua Hawson, Robert D. Anderson, Michael Lim, David Chieng, Stephen A. Joseph, Alex McLellan, Joseph B. Morton, Paul B. Sparks, Geoffrey Lee, Prashanthan Sanders, and Peter M. Kistle

    Simultaneous epicardial-endocardial mapping of the sinus node in humans with structural heart disease: Impact of overdrive suppression on sinoatrial exits.

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    Background: The 3-dimensional (3D) nature of sinoatrial node (SAN) function has not been characterized in the intact human heart. Objective: The purpose of this study was to characterize the 3D nature of SAN function in patients with structural heart disease (SHD) using simultaneous endocardial-epicardial (endo-epi) phase mapping. Methods: Simultaneous intraoperative endo-epi SAN mapping was performed during sinus rhythm at baseline (SR(baseline)) and postoverdrive suppression at 600 ms (SR(post-pace600)) and 400 ms (SR(post-pace400)) using 2 Abbott Advisor HD Grid Mapping Catheters. Unipolar and bipolar electrograms (EGMs) were exported for phase analysis to determine (1) activation exits; (2) wavefront propagation sequence; (3) endo-epi dissociation; and (4) fractionation. Comparison of these variables was made among the 3 rhythms from an endo-epi perspective. Results: Sixteen patients with SHD were included. SR(baseline) activations were unicentric and predominantly exited cranially (87.5%) with endo-epi synchrony. However, with overdrive suppression, a tendency for caudal exit shift and endo-epi asynchrony was observed: SR(post-pace600) vs SR(baseline): cranial endo 75% vs 87.5% (P = .046); cranial epi 68.8% vs 87.5% (P = 0.002); caudal endo 12.5% vs 6.2% (P = 0.215); caudal epi 25% vs 6.2% (P = .0003); and SR(post-pace400) vs SR(baseline): cranial endo 81.3% vs 87.5% (P = 0.335); cranial epi 68.7% vs 87.5% (P = 0.0034; caudal endo 12.5% vs 6.2% (P = .148); caudal epi 31.2% vs 6.2% (P = 0.0017), consistent with multicentricity. EGM fractionation was more prevalent with overdrive suppression. Conclusion: During mapping of the intact human heart, SAN demonstrated redundancy of sinoatrial exits with postoverdrive shift in sites of earliest activation and epi-endo dissociation of sinoatrial exits.Ramanathan Parameswaran, Geoffrey Lee, Gwilym M. Morris, Alistair Royse, John Goldblatt, Marco Larobina, Troy Watts, Chrishan J. Nalliah, Geoffrey Wong, Ahmed M. Al-Kaisey, Robert D. Anderson, Aleksandr Voskoboinik, Hariharan Sugumar, David Chieng, Prashanthan Sanders, Peter M. Kistler, Jonathan M. Kalma

    Impact of Catheter Ablation on Cognitive Function in Atrial Fibrillation: A Randomized Control Trial

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    BACKGROUND: Early postoperative cognitive dysfunction (POCD) has been reported following atrial fibrillation (AF) ablation. However, whether POCD is persistent long-term is unknown. OBJECTIVES: The purpose of this study was to determine if AF catheter ablation is associated with persistent cognitive dysfunction at 12-month follow-up. METHODS: This is a prospective study of 100 patients with symptomatic AF who failed at least 1 antiarrhythmic drug randomized to either ongoing medical therapy or AF catheter ablation and followed up for 12 months. Changes in cognitive performance were assessed using 6 cognitive tests administered at baseline and during follow-up (3, 6, and 12 months). RESULTS: A total of 96 participants completed the study protocol. Mean age was 59 ± 12 years (32% women, 46% with persistent AF). The prevalence of new cognitive dysfunction in the ablation arm compared with the medical arm was as follows: at 3 months: 14% vs 2%; P = 0.03; at 6 months: 4% vs 2%; P = NS; and at 12 months: 0% vs 2%; P = NS. Ablation time was an independent predictor of POCD (P = 0.03). A significant improvement in cognitive scores was seen in 14% of the ablation arm patients at 12 months compared with no patients in the medical arm (P = 0.007). CONCLUSIONS: POCD was observed following AF ablation. However, this was transient with complete recovery at 12-month follow-up.Ahmed M. Al-Kaisey, Ramanathan Parameswaran, Christina Bryant, Robert D. Anderson, Joshua Hawson, David Chieng, Aleksandr Voskoboinik, Hariharan Sugumar, Danielle West, Sonia Azzopardi, Sue Finch, Geoffrey Wong, Stephen A. Joseph, Alex McLellan, Liang-Han Ling, Prashanthan Sanders, Geoffrey Lee, Peter M. Kistler, Jonathan M. Kalma

    Evidence for an extended reconnection line at the dayside magnetopause

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    We report in-situ detection by two spacecraft of oppositely directed jets of plasma emanating from a magnetic reconnection site at the Earth’s dayside magnetopause, confirming a key element inherent in all reconnection scenarios. The dual-spacecraft (Equator-S and Geotail) observations at the flank magnetopause, together with SuperDARNHalley radar observations of the subsolar cusp region, reveal the presence of a rather stable and extended reconnection line which lies along the equatorial magnetopause. These observations were made under persistent southward interplanetary magnetic field (IMF) conditions, implying that under these conditions the reconnection sites are determined by the large-scale interactions between the solar wind magnetic field and the dayside magnetosphere, rather than by local conditions at the magnetopause. Control by local conditionswould result in patchy reconnection, distributed in a less well-organized fashion over the magnetopause surface
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