81 research outputs found
Tilting chains of negative curves on rational surfaces
We introduce the notion of exact tilting objects, which are partial tilting
objects inducing an equivalence between the abelian category generated by
and the category of modules over the endomorphism algebra of .
Given a chain of sufficiently negative rational curves on a rational surface,
we construct an exceptional sequence whose universal extension is an exact
tilting object. For a chain of (-2)-curves, we obtain an equivalence with
modules over a well known algebra.Comment: 13 page
Гендерний аспект вивчення жаргонної лексики
В статье определяется понятие "общий жаргон", обосновывается актуальность гендерного подхода к изучению жаргонизмов. На материале выборок из
словарей, художественной литературы, по результатам проведенного автором
психолингвистического эксперимента осуществляется семантический анализ,
определяются способы образования жаргонизмов на обозначение женщин в украинском языке.У статті визначається поняття "загальний жаргон", обґрунтовується актуальность ґендерного підходу до вивчення жаргонізмів. На матеріалі вибірок зі
словників, художньої літератури, за результатами проведеного автором психолінгвістичного експерименту здійснюється семантичний аналіз, визначаються
способи утворення жаргонізмів на позначення жінок в українській мові.The author of the article defines the concept "general jargon", bases actuality of
gender aspect of jargon words investigation. Using dictionaries, literature and the results
of psycho-linguistic experiment, the author analyses semantic and formation
ways of jargon words for designation of women in Ukrainian
Опыт лечения врожденных кист яичников у девочек на первом году жизни
В статті представлено три випадки оперативного лікування методом лапароскопії вроджених кист
яєчника. Найчастіше перекрут вродженої кисти яєчника відбувається внутрішньоутробно, що може привести
до самоампутації додатків матки з боку ураження. Показанням до оперативного лікування можуть слугувати
відсутність регресу утворення, характерні ехоскопічні та доплерометричні ознаки.Three cases of laparoscopic treatment of congenital ovarian cysts are presented in the article. More often twisting
of congenital ovarian cyst could happen intrauterously, what could cause autoamputation of adnexa. Indications to
surgery could be an absence of regression of cyst and/or certain ultrasound and Doppler signs
Re-establishment of Spodoptera teferii Laporte in Rougeot (Lepidoptera: Noctuidae, Noctuinae), with an updated molecular phylogeny for the genus Spodoptera Guenee
International audienceThe genus Spodoptera Guenee (Lepidoptera: Noctuidae, Noctuinae) is a group of economic importance which encompasses several major pests of crops worldwide. Although this genus has been the focus of many studies, the status of several Spodoptera species is still unstable, especially in the light of recent molecular analyses. In 2015 five Spodoptera specimens collected in Ethiopia were first identified as S. apertura (Walker). However, preliminary studies suggested that these specimens belong to a distinct species, S. teferii Laporte in Rougeot, which has been previously synonymized with S. apertura. In this study, on the basis of morphological and molecular evidence, we re-establish the species status of S. teferii. We provide a supplemental description of S. teferii male and the first description of S. teferii female. We also conducted several molecular analyses. First, we reconstructed an updated phylogeny for the genus based on a multilocus dataset (four mitochondrial and three nuclear gene fragments) including S. teferii and 28 of the 31 currently recognized Spodoptera species; the results of phylogenetic analyses support the hypothesis that S. teferii is more closely related to the clade encompassing S. littoralis (Boisduval), S. litura (Fabricius), S. pectinicornis (Hampson) and S. picta (Guerin-Meneville) than to S. apertura. Second, we carried out molecular species delimitation analyses on a 683-specimen dataset that also clearly support the status of S. teferii as a species distinct to S. apertura
Development of microsatellite markers for the yellow-legged Asian hornet, Vespa velutina, a major threat for European bees
We report the characterization of fifteen microsatellite markers in Vespa velutina, an invasive hornet from Asia that has been unintentionally introduced in France before 2005. It is expanding rapidly, covering one third of the French territory and northern Spain, and causes severe losses to honeybee colonies. An enrichment protocol was used to isolate microsatellite loci, and polymorphism was explored in an invasive population from France and in a population from the native mainland location in China. These markers showed a number of alleles per locus and per population ranging from 1 to 11, and expected heterozygosities ranging from 0.151 to 0.891. These polymorphic markers will be useful to identify the source of the invading population and to discover the invasion pathways
Phylogeography of Sesamia cretica Lederer (Lepidoptera : Noctuidae)
The greater sugarcane borer, Sesamia cretica Lederer (Lepidoptera: Noctuidae) is an important pest of maize, sorghum and sugarcane in Africa, the Middle East, and Mediterranean Europe. However, the population genetics and phylogeography of this pest are unknown. Some insect pests exhibit genetic differentiation congruent with their geographical location and ecological conditions. To evaluate this, a molecular analysis was conducted on populations of S. cretica collected from Ethiopia, Eritrea, Kenya, Cameroon and Iran, using the cytochrome c oxidase subunit I (COI) region of the mitochondrial genome. Phylogenetic analyses based on neighbor joining tree separated the 22 specimens into two clades, the Ethiopian and Afro-Asian. The clades diverged long before the domestication of sorghum and the introduction of sugarcane in Africa. Analysis of molecular variance (AMOVA) indicated significant genetic differentiation among the clades. The observed genetic variation between the clades was further accompanied by restricted gene flow. The results of mismatch distribution analyses were consistent with the demographic expansion of the clades
Isolation and characterization of polymorphic microsatellites in the Potato Tuber Moth Tecia solanivora (Povolny, 1973) (Lepidoptera : Gelechiidae)
Nine polymorphic microsatellite markers were isolated from Tecia solanivora, one of the most serious pests of potato tubers in Central and South America. As found in other studies of Lepidoptera, development of microsatellites is a difficult task: in our case, despite the large number of clones sequenced (796), of which 70 were unique, only nine loci were found to be both variable, and in Hardy-Weinberg equilibrium, No null alleles were detected. The loci were tested in three other co-occurring Gelechiidae species, one of which was variable. These loci will be used to provide a greater understanding of the genetic changes occurring during the invasive process in this species
- …