159 research outputs found

    Base excision repair intermediates are mutagenic in mammalian cells

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    Base excision repair (BER) is the main pathway for repair of DNA damage in mammalian cells. This pathway leads to the formation of DNA repair intermediates which, if still unsolved, cause cell lethality and mutagenesis. To characterize mutations induced by BER intermediates in mammalian cells, an SV-40 derived shuttle vector was constructed carrying a site-specific lesion within the recognition sequence of a restriction endonuclease. The mutation spectra of abasic (AP) sites, 5′-deoxyribose-5-phosphate (5′dRp) and 3′-[2,3-didehydro-2,3-dideoxy-ribose] (3′ddR5p) single-strand breaks (ssb) in mammalian cells was analysed by RFLP/PCR and mutation frequency was estimated by quantitative PCR. Point mutations were the predominant events occurring at all BER intermediates. The AP site-induced mutation spectrum supports evidence for the ‘A-rule’ and is also consistent with the use of the 5′ neighbouring base to instruct nucleotide incorporation (5′-rule). Preferential adenine insertion was also observed after in vivo replication of 5′dRp or 3′ddR5p ssb. We provide original evidence that not only the abasic site but also its derivatives ‘faceless’ BER intermediates are mutagenic, with a similar mutation frequency, in mammalian cells. Our findings support the hypothesis that unattended BER intermediates could be a constant threat for genome integrity as well as a spontaneous source of mutations

    Evaluation of Shear Bond Strength and Adhesive Remnant Index of Orthodontic Brackets Bonded Directly or Indirectly With Adhesive Resin Cements to Bovine Enamel

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    The aim of this study was to evaluate differences in shear bond strength and in Adhesive Remnant Index using direct and indirect bonding techniques with two different resin cements A total of cow mandibular incisors were analyzed Inclusion criteria were intact buccal surfaces no carious lesions recent extraction proper preparation and conservation Elements were extracted immersed in a thymol solution and secured in cold resin The material tested were Transbond Unitek M Monrovia Calif and Kuraray Kuraray Medical Tokyo Japan Teeth were divided in four groups Direct technique Transbond Direct technique Kurasper Indirect technique Transbond Indirect technique Kurasper Upper right central incisor brackets were used in all groups and bonded directly or indirectly Samples were tested for ARI and shear bond strength with a load cell of KN The two way ANOVA test showed no significant difference for bonding technique p composite cement used p or interaction between these two variables p The Chi square test showed no significant difference in failure sites ARI in all groups p There is no significant difference in adhesion force and in failure sites between direct and indirect techniques with both cement

    A novel plasmid carrying blaCTX-M-15 identified in commensal Escherichia coli from healthy pregnant women in Ibadan, Nigeria

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    AbstractThe aim of this study was to investigate the molecular characteristics of commensal Escherichia coli producing extended-spectrum β-lactamases and showing fluoroquinolone resistance circulating in a healthy population in Ibadan, Nigeria. In total, 101 faecal samples from healthy pregnant women on the day of admission to hospital were collected and plated on eosin–methylene blue agar supplemented with cefotaxime. Genotyping demonstrated the presence of the blaCTX-M-15 gene in all of the cefotaxime-resistant isolates (n=32), and there was circulation of prevalent clones. The aac(6′)-Ib-cr, qnrS1, qepA1 and qnrB1 genes were identified in several strains. A novel plasmid supporting the spread of the blaCTX-M-15, blaTEM-1 and qnrS1 genes was identified in these isolates by complete DNA sequencing

    A Century of Drought in Hawaiʻi: Geospatial Analysis and Synthesis across Hydrological, Ecological, and Socioeconomic Scales

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    Drought is a prominent feature of Hawaiʻi’s climate. However, it has been over 30 years since the last comprehensive meteorological drought analysis, and recent drying trends have emphasized the need to better understand drought dynamics and multi-sector effects in Hawaiʻi. Here, we provide a comprehensive synthesis of past drought effects in Hawaiʻi that we integrate with geospatial analysis of drought characteristics using a newly developed 100-year (1920–2019) gridded Standardized Precipitation Index (SPI) dataset. The synthesis examines past droughts classified into five categories: Meteorological, agricultural, hydrological, ecological, and socioeconomic drought. Results show that drought duration and magnitude have increased significantly, consistent with trends found in other Pacific Islands. We found that most droughts were associated with El Niño events, and the two worst droughts of the past century were multi-year events occurring in 1998–2002 and 2007–2014. The former event was most severe on the islands of O’ahu and Kaua’i while the latter event was most severe on Hawaiʻi Island. Within islands, we found different spatial patterns depending on leeward versus windward contrasts. Droughts have resulted in over $80 million in agricultural relief since 1996 and have increased wildfire risk, especially during El Niño years. In addition to providing the historical context needed to better understand future drought projections and to develop effective policies and management strategies to protect natural, cultural, hydrological, and agricultural resources, this work provides a framework for conducting drought analyses in other tropical island systems, especially those with a complex topography and strong climatic gradients

    Contribution to the floristic knowledge of eastern Irpinia and Vulture-Melfese area (Campania and Basilicata, southern Italy)

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    In order to improve the floristic knowledge of the Italian territory, we report the inventory of the taxa collected during the annual field trip of the working group for Floristics, Systematics and Evolution of the Italian Botanical Society held in 2015 in eastern Irpinia and Vulture-Melfese area (South Italy). The investigated territories are located in southern Apennines, along the border between the Campania and Basilicata administrative regions. These areas are scarcely known in terms of vascular flora. The floristic samplings were performed in 19 sites selected as representative of the local environmental diversity as regards to climate, litho-morphology and land-use. The research led to the identification of 4,137 specimens of vascular plants, belonging to 815 species and subspecies, 399 genera, and 85 families. Among these taxa, 42 were endemic to Italy, 38 were included in the IUCN Red List of the Italian Flora, 28 were alien and 5 were cryptogenic in Campania and/ or Basilicata administrative regions. Two taxa, Aquilegia coerulea (casual alien, native to North America) and Lolium ×boucheanum (native), were found to be new for Italy. On the basis of the available floristic literature the first one is also to be considered new for the European flora. At regional scale, we have found 18 taxa new for the Campania and 15 new for the Basilicata region. Finally, 10 taxa were confirmed for Campania. Data obtained during this study, confirmed the important role of a collaborative approach among botanists and the great relevance of these territories for plant diversity

    Foreign rule?: transnational, national, and local perspectives on Venice and Venetia within the “multinational” empire

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    The history of the Habsburg Empire in the post-Napoleonic era is frequently approached from the perspective of its various component nationalities. These were traditionally portrayed in the historiography as engaged in more-or-less open struggle with control from Vienna. This article argues that the over-privileging of such national categories can distort the picture. By looking at a number of case studies – the naming of Lombardy-Venetia, the Biblioteca italiana, the Panteon veneto – the relationship between Venice (and its Terraferma) and Habsburg rule during the second Austrian domination is examined. It will be argued that it is more profitable to see Venetian identities (municipal, local, Italian, and as part of a wider transnational European culture) as capable of working for as well as against the empire, and that Habsburg policy was as often concerned with managing potential local rivalries (notably between Lombards and Venetians) as with controlling a perceived Italian threat. It is also suggested that, while cultivation of local identity was often used to reinforce the national, the Austrian authorities were also happy to annex both to further imperial interests

    Notulae to the Italian alien vascular flora: 14

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    In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, and status changes for Italy or for Italian administrative regions. Nomenclatural and distribution updates, published elsewhere, and corrections are provided as Suppl. materia

    Notulae to the Italian alien vascular flora: 14

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    In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, and status changes for Italy or for Italian administrative regions. Nomenclatural and distribution updates, published elsewhere, and corrections are provided as Suppl. material

    Il farsi mondo delle donne. Scrivere il cinema

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    Numero 3 dei Quaderni del Centro di Documentazione internazionale Alma Sabatini, è dedicato a Bianca Pomeranzi, dal cui scritto prende il titolo, e presenta contributi rivolti alla rappresentanza e alla rappresentazione delle differenza nella scrittura cinematografica delle donn
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