150 research outputs found

    Duality Defects in E8E_8

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    We classify all non-invertible Kramers-Wannier duality defects in the E8E_8 lattice Vertex Operator Algebra (i.e. the chiral (E8)1(E_8)_1 WZW model) coming from Zm\mathbb{Z}_m symmetries. We illustrate how these defects are systematically obtainable as Z2\mathbb{Z}_2 twists of invariant sub-VOAs, compute defect partition functions for small mm, and verify our results against other techniques. Throughout, we focus on taking a physical perspective and highlight the important moving pieces involved in the calculations. Kac's theorem for finite automorphisms of Lie algebras and contemporary results on holomorphic VOAs play a role. We also provide a perspective from the point of view of (2+1)d Topological Field Theory and provide a rigorous proof that all corresponding Tambara-Yamagami actions on holomorphic VOAs can be obtained in this manner. We include a list of directions for future studies.Comment: 51+15 pages, 7 figures, 8 table

    Rapid weed adaptation and range expansion in response to agriculture over the past two centuries

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    North America has experienced a massive increase in cropland use since 1800, accompanied more recently by the intensification of agricultural practices. Through genome analysis of present-day and historical samples spanning environments over the past two centuries, we studied the effect of these changes in farming on the extent and tempo of evolution across the native range of the common waterhemp (Amaranthus tuberculatus), a now pervasive agricultural weed. Modern agriculture has imposed strengths of selection rarely observed in the wild, with notable shifts in allele frequency trajectories since agricultural intensification in the 1960s. An evolutionary response to this extreme selection was facilitated by a concurrent human-mediated range shift. By reshaping genome-wide diversity across the landscape, agriculture has driven the success of this weed in the 21st century

    African genomes illuminate the early history and transition to selfing in Arabidopsis thaliana

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    Over the past 20 y, many studies have examined the history of the plant ecological and molecular model, Arabidopsis thaliana, in Europe and North America. Although these studies informed us about the recent history of the species, the early history has remained elusive. In a large-scale genomic analysis of African A. thaliana, we sequenced the genomes of 78 modern and herbarium samples from Africa and analyzed these together with over 1,000 previously sequenced Eurasian samples. In striking contrast to expectations, we find that all African individuals sampled are native to this continent, including those from sub-Saharan Africa. Moreover, we show that Africa harbors the greatest variation and represents the deepest history in the A. thaliana lineage. Our results also reveal evidence that selfing, a major defining characteristic of the species, evolved in a single geographic region, best represented today within Africa. Demographic inference supports a model in which the ancestral A. thaliana population began to split by 120-90 kya, during the last interglacial and Abbassia pluvial, and Eurasian populations subsequently separated from one another at around 40 kya. This bears striking similarities to the patterns observed for diverse species, including humans, implying a key role for climatic events during interglacial and pluvial periods in shaping the histories and current distributions of a wide range of species.Peer Reviewe

    Encuesta sobre hipoglucemia en pacientes con diabetes tratados con insulina: la población colombiana del International Operations Hypoglycemia Assessment Tool

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    Introduction: The non-interventional International Operations Hypoglycemia Assessment Tool (IO-HAT) study assessed the incidence of hypoglycemia in patients with insulin-treated diabetes across nine countries, including a cohort of patients in Colombia.Materials and methods: Hypoglycemia incidence among patients with insulin-treated diabetes was assessed across 26 sites in Colombia. Hypoglycaemic events (any, nocturnal or severe) were reported in self-assessment questionnaires (SAQ) and patient diaries based on capillary blood glucose measurement or symptoms. Retrospective events (severe events 6 months before baseline and any event 4 weeks before baseline) were recorded in SAQ, Part 1, and prospective events (4 weeks from baseline) were recorded in SAQ, Part 2, and patient diaries. Differences in hypoglycemia incidence reported in the retrospective and prospective periods were assessed using two-sided tests.Results: Of the 664 patients assessed, 213 had type 1 diabetes (T1D) and 451 had type 2 diabetes (T2D). Nearly all patients experienced at least one hypoglycaemic event in the prospective period (97.1% T1D; 93.3% T2D). Rates of hypoglycemia (events per personyear, PPY) were higher prospectively than retrospectively for any hypoglycemia (T1D: 121.6 vs. 83.2, p<0.001; T2D: 28.1 vs. 24.6, p=0.127) and severe hypoglycemia (T1D: 15.3 vs. 9.2, p=0.605; T2D: 9.5 vs. 3.5 p=0.040).Conclusion: These results, the first from a patient-reported dataset on hypoglycemia in insulin-treated patients with diabetes in Colombia, show that patients reported higher rates of any hypoglycemia during the prospective period. Clinical trial registration number: NCT02306681Introducción. En el estudio no intervencionista International Operations Hypoglycemia Assessment Tool (IO-HAT), se evalúo la incidencia de hipoglucemia en pacientes diabéticos tratados con insulina en nueve países, incluido Colombia.Materiales y métodos. La incidencia de hipoglucemia entre pacientes diabéticos tratados con insulina se evaluó en 26 centros médicos en Colombia. Los episodios de hipoglucemia determinados con base en la medición de la glucemia capilar o en los síntomas se reportaron en el cuestionario de autoevaluación (Self-Assessment Questionnaire, SAQ) y en el diario del paciente. Los episodios retrospectivos (episodios graves y cualquiera ocurrido 6 meses y 4 semanas antes del inicio del estudio, respectivamente) se registraron en el SAQ, parte 1, y los eventos prospectivos (4 semanas desde el inicio), en el SAQ, parte 2, y en el diario del paciente. Las diferencias en la incidencia de la hipoglucemia entre los períodos retrospectivo y prospectivo se evaluaron mediante una prueba de dos colas.Resultados. De los 664 pacientes evaluados, 213 tenían diabetes de tipo 1 y 451 tenían diabetes de tipo 2. Casi todos los pacientes experimentaron al menos un episodio de hipoglucemia en el período prospectivo (97,1 %, diabetes de tipo 1, y 93,3 %, diabetes de tipo 2). Los índices de hipoglucemia (episodios año-persona) fueron mayores prospectivamente que retrospectivamente para cualquier tipo de hipoglucemia (diabetes de tipo 1: 121,6 Vs. 83,2; p<0,001; la diabetes de tipo 2: 28,1 Vs. 24,6; p=0,127) y para la hipoglucemia grave (diabetes de tipo 1: 15,3 Vs. 9,2; p=0,605; diabetes de tipo 2: 9,5 Vs. 3,5; p=0,040).Conclusión. Estos resultados, que constituyen el primer conjunto de datos sobre hipoglucemia informados por pacientes diabéticos colombianos tratados con insulina, evidenciaron tasas más altas para ambos tipos de hipoglucemia durante el período prospectivo. Número de registro del ensayo clínico: NCT0230668

    Neandertal and Denisovan DNA from Pleistocene sediments.

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    Although a rich record of Pleistocene human-associated archaeological assemblages exists, the scarcity of hominin fossils often impedes the understanding of which hominins occupied a site. Using targeted enrichment of mitochondrial DNA we show that cave sediments represent a rich source of ancient mammalian DNA that often includes traces of hominin DNA, even at sites and in layers where no hominin remains have been discovered. By automation-assisted screening of numerous sediment samples we detect Neandertal DNA in eight archaeological layers from four caves in Eurasia. In Denisova Cave we retrieved Denisovan DNA in a Middle Pleistocene layer near the bottom of the stratigraphy. Our work opens the possibility to detect the presence of hominin groups at sites and in areas where no skeletal remains are found

    Phytochemical composition and antioxidant capacity of the aqueous extracts of Malva sylvestris L. and Malva pseudolavatera Webb & Berthel.

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    Context: Malva spp. have been widely used in the world as traditional remedies. In Ecuadorian markers Malva sylvestris and Malva pseudolavatera are the species most commercialized. However, the scientific information about M. pseudolavatera is little. Aims: To determine the chemical composition and antioxidant capacity of the aqueous extracts of the leaves of both species. Methods: Aqueous extracts were partitioned with butanol and the fractions obtained were analyzed by GC/MS. Total extracts were evaluated as antioxidants using FRAP, DPPH and ABTS assays. Results: Differences in the chemical composition were found between the extracts. Both extracts showed the presence of polysaccharides, phenolic acids and fatty acids, but in M. sylvestris were identified polyols, which there was not observed in M. pseudolavatera. The aqueous extracts showed free radical scavenging and ferric reducing power capacities in vitro assays, being M. sylvestris the most promissory antioxidant, possibly due to the presence of polyols in the extract. In the present research were reported 39 phytochemical compounds by first time for the specie M. pseudolavatera. Conclusions: Aqueous extracts of the leaves of M. sylvestris and M. pseudolavatera showed antioxidant capacity associated with the presence of phenolic acids, polysaccharides and flavonoids in the extracts. Keywords: antioxidant; gas chromatography; Malva pseudolavatera; Malva sylvestris; phytochemicals

    Studies of micronuclei and other nuclear abnormalities in red blood cells of Colossoma macropomum exposed to methylmercury

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    The frequencies of micronuclei (MN) and morphological nuclear abnormalities (NA) in erythrocytes in the peripheral blood of tambaqui (Colossoma macropomum), treated with 2 mg.L−1 methylmercury (MeHg), were analyzed. Two groups (nine specimens in each) were exposed to MeHg for different periods (group A - 24 h; group B - 120 h). A third group served as negative control (group C, untreated; n = 9). Although, when compared to the control group there were no significant differences in MN frequency in the treated groups, for NA, the differences between the frequencies of group B (treated for 120 h) and the control group were extremely significant (p < 0.02), thus demonstrating the potentially adverse effects of MeHg on C. macropomum erythrocytes after prolonged exposure
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