525 research outputs found
Feast of sacrifice and orf, Milan, Italy, 2015–2018
Orf (ecthyma contagiosum) is an infection of the skin caused by a DNA virus belonging to the genus Parapoxvirus. We recently observed 7 cases of orf in Muslim men living in the metropolitan area of Milan, Italy, who acquired the infection after the Feast of Sacrific
Leptonic decay constants fK, fD and fDs with Nf = 2+1+1 twisted-mass lattice QCD
We present a lattice QCD calculation of the pseudoscalar decay constants fK,
fD and fDs performed using the gauge configurations produced by the European
Twisted Mass Collaboration with Nf = 2 + 1 + 1 dynamical quarks, which include
in the sea, besides two light mass degenerate quarks, also the strange and
charm quarks with masses close to their values in the real world. The
simulations are based on a unitary setup for the two light mass-degenerate
quarks and on a mixed action approach for the strange and charm quarks. We use
data simulated at three different values of the lattice spacing in the range
0.06 - 0.09 fm and at pion masses in the range 210 - 450 MeV. Our main results
are: fK+ / fpi+ = 1.184 (16), fK+ = 154.4 (2.0) MeV, which incorporate the
leading strong isospin breaking correction due to the up- and down-quark mass
difference, and fK = 155.0 (1.9) MeV, fD = 207.4 (3.8) MeV, fDs = 247.2 (4.1)
MeV, fDs / fD = 1.192 (22) and (fDs / fD) / (fK / fpi) = 1.003 (14) obtained in
the isospin symmetric limit of QCD. Combined with the experimental measurements
of the leptonic decay rates of kaon, pion, D- and Ds-mesons our results lead to
the following determination of the CKM matrix elements: |Vus| = 0.2269 (29),
|Vcd| = 0.2221 (67) and |Vcs| = 1.014 (24). Using the latest value of |Vud|
from superallowed nuclear beta decays the unitarity of the first row of the CKM
matrix is fulfilled at the permille level.Comment: 20 pp., 4 figures; revised version to appear in PRD; improved
calculation of IB effects for fK+; minor changes in the final values. arXiv
admin note: text overlap with arXiv:1403.450
BoolSurf: Boolean Operations on Surfaces
We port Boolean set operations between 2D shapes to surfaces of any genus, with any number of open boundaries. We combine shapes bounded by sets of freely intersecting loops, consisting of geodesic lines and cubic BĂ©zier splines lying on a surface. We compute the arrangement of shapes directly on the surface and assign integer labels to the cells of such arrangement. Differently from the Euclidean case, some arrangements on a manifold may be inconsistent. We detect inconsistent arrangements and help the user to resolve them. Also, we extend to the manifold setting recent work on Boundary-Sampled Halfspaces, thus supporting operations more general than standard Booleans, which are well defined on inconsistent arrangements, too. Our implementation discretizes the input shapes into polylines at an arbitrary resolution, independent of the level of resolution of the underlying mesh. We resolve the arrangement inside each triangle of the mesh independently and combine the results to reconstruct both the boundaries and the interior of each cell in the arrangement. We reconstruct the control points of curves bounding cells, in order to free the result from discretization and provide an output in vector format. We support interactive usage, editing shapes consisting up to 100k line segments on meshes of up to 1M triangles
A short history of tattoo
Tattoo is a permanent pigmentation of the skin resulting from the introduction of exogenous substances. If this happens unintentionally\u2014for example, after road injuries\u2014it is called traumatic tattoo. However, the most common tattoos are decorative, related to current fashion or to a symbolic meaning.
The etymological origin of the word tattoo is believed to have 2 major derivations: the first is from the Polynesian word \u201cta\u201d which means \u201cstriking something,\u201d and the second is the Tahitian word \u201ctatau\u201d which means \u201cto mark something.\u201d This word was introduced in Europe by the English explorer James Cook, who described the Polynesian technique of \u201ctattaw\u201d in his narrative of the voyage
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