5,039 research outputs found
Moduli and periods of simply connected Enriques surfaces
We describe a period map for those simply connected Enriques surfaces in
characteristic 2 whose canonical double cover is K3. The moduli stack for these
surfaces has a Deligne-Mumford quotient that is an open substack of a -bundle over the period space. We also give some general results relating
local and global moduli for algebraic varieties and describe the difference in
their dimensions in terms of the failure of the automorphism group scheme to be
reduced
A Look at the Life and Work of Sylvia L. Thrupp (1903-1997), Medieval Historian and Social Scientist
Anisotropic thermal expansion of Fe1.06Te and FeTe0.5Se0.5 single crystals
Heat capacity and anisotropic thermal expansion was measured for Fe1.06Te and
FeTe0.5Se0.5 single crystals. Previously reported phase transitions are clearly
seen in both measurements. In both cases the thermal expansion is anisotropic.
The uniaxial pressure derivatives of the superconducting transition temperature
in FeTe0.5Se0.5 inferred from the Ehrenfest relation have opposite signs for
in-plane and c-axis pressures. Whereas the Gruneisen parameters for both
materials are similar and only weakly temperature-dependent above ~ 80 K, at
low temperatures (in the magnetically ordered phase) the magnetic contribution
to the Gruneisen parameter in Fe1.06Te is significantly larger than electron
and phonon contributions combined
-cofiniteness of 2-cyclic permutation orbifold models
In this article, we consider permutation orbifold models of -cofinite
vertex operator algebras of CFT type. We show the -cofiniteness of the
2-cyclic permutation orbifold model for an arbitrary
-cofinite simple vertex operator algebra of CFT type. We also give a
proof of the -cofiniteness of a -orbifold model of the
lattice vertex operator algebra associated with a rank one positive
definite even lattice by using our result and the -cofiniteness of
.Comment: 25 pages, no figure, some typo are correcte
SUSY vertex algebras and supercurves
This article is a continuation of math.QA/0603633 Given a strongly conformal
SUSY vertex algebra V and a supercurve X we construct a vector bundle V_X on X,
the fiber of which, is isomorphic to V. Moreover, the state-field
correspondence of V canonically gives rise to (local) sections of these vector
bundles. We also define chiral algebras on any supercurve X, and show that the
vector bundle V_X, corresponding to a SUSY vertex algebra, carries the
structure of a chiral algebra.Comment: 50 page
A new species in the major malaria vector complex sheds light on reticulated species evolution
Complexes of closely related species provide key insights into the rapid and independent evolution of adaptive traits. Here, we described and studied Anopheles fontenillei sp.n., a new species in the Anopheles gambiae complex that we recently discovered in the forested areas of Gabon, Central Africa. Our analysis placed the new taxon in the phylogenetic tree of the An. gambiae complex, revealing important introgression events with other members of the complex. Particularly, we detected recent introgression, with Anopheles gambiae and Anopheles coluzzii, of genes directly involved in vectorial capacity. Moreover, genome analysis of the new species allowed us to clarify the evolutionary history of the 3La inversion. Overall, An. fontenillei sp.n. analysis improved our understanding of the relationship between species within the An. gambiae complex, and provided insight into the evolution of vectorial capacity traits that are relevant for the successful control of malaria in Africa
Overview of the CLEF-2019 Checkthat! LAB: Automatic identification and verification of claims. Task 2: Evidence and factuality
We present an overview of Task 2 of the second edition of the CheckThat! Lab at CLEF 2019. Task 2 asked (A) to rank a given set of Web pages with respect to a check-worthy claim based on their usefulness for fact-checking that claim, (B) to classify these same Web pages according to their degree of usefulness for fact-checking the target claim, (C) to identify useful passages from these pages, and (D) to use the useful pages to predict the claim's factuality. Task 2 at CheckThat! provided a full evaluation framework, consisting of data in Arabic (gathered and annotated from scratch) and evaluation based on normalized discounted cumulative gain (nDCG) for ranking, and F1 for classification. Four teams submitted runs. The most successful approach to subtask A used learning-to-rank, while different classifiers were used in the other subtasks. We release to the research community all datasets from the lab as well as the evaluation scripts, which should enable further research in the important task of evidence-based automatic claim verification
The role of host PrP in Transmissible Spongiform Encephalopathies
AbstractPrP has a central role in the Transmissible Spongiform Encephalopathies (TSEs), and mutations and polymorphisms in host PrP can profoundly alter the host's susceptibility to a TSE agent. However, precisely how host PrP influences the outcome of disease has not been established. To investigate this we have produced by gene targeting a series of inbred lines of transgenic mice expressing different PrP genes. This allows us to study directly the influence of the host PrP gene in TSEs. We have examined the role of glycosylation, point mutations, polymorphisms and PrP from different species on host susceptibility and the disease process both within the murine species and across species barriers
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