Segmentation defects are often seen with congenital atlantoaxial dislocation (AAD) though an associated absence of posterior arch of C2 and butterfly C3 is rare. Apart from rarity, the combination of formation and segmentation defects adds to the management dilemma. We report a case of AAD with assimilated atlas, absent C2 posterior arch, C3 butterfly vertebra with floating posterior elements, ...

Surveys of butterfly and moth diversity in tropical forest fragments suggest that nocturnality confers a dispersal, and possibly a survival, advantage. The butterfly faunas of smaller fragments were depauperate; in contrast, the species richness of nocturnal moths was similar in all fragments and even in pasture. The lack of correlation between butterfly and moth species richness among fragment...

Stochastic gradient descent is a widely used method to find locally-optimal models in machine learning and data mining. However, it is naturally a sequential algorithm, and parallelization involves severe compromises because the cost of synchronizing across a cluster is much larger than the time required to compute an optimal-sized gradient step. Here we explore butterfly mixing, where gradient...

We are interested in the experimental characterization of the Hofstadter butterfly by means of acoustical waves. The transmission of an acoustic pulse through an array of 60 variable and resonant scatterers periodically distribued along a waveguide is studied. An arbitrary scattering arrangement is realized by using the variable length of each resonator cavity. For a periodic modulation, the st...

Mapping an algorithm to an architecture with faults is an important problem in parallel processing. This paper deals with wrapped butterfly architectures with edge faults. We investigate the effect of automorphisms of a wrapped butterfly on its edges. Given a fault set, one can then choose an appropriate automorphism to map the algorithm to use only fault-free edges. By using an algebraic model...

Density functional theory calculations on the Co(2)(NO)(4)(SR)(2) compounds (R = CH(3), CF(3) and C(4)H(9)) predict butterfly and open isomeric structures with and without a direct Co-Co bond. The open Co(2)(NO)(4)(SR)(2) structures are favored over the butterfly isomers, in terms of relative energy. Furthermore the open structures are predicted to have approximately twice as large HOMO-LUMO ga...

Arithmetic operations of high complexity are widely used in Digital Signal Processing (DSP) applications. The FFT algorithms use butterfly method in order to find the output. The Butterfly method includes an addition followed by a multiplication. In this work, we focus on optimizing the design of the fused Add-Multiply (FAM) operator for increasing performance and hence the FFT. Optimization of...

We investigated the interacting impacts of urban landscape and gardening practices on the species richness and total abundance of communities of common butterfly communities across France, using data from a nationwide monitoring scheme. We show that urbanization has a strong negative impact on butterfly richness and abundance but that at a local scale, such impact could be mitigated by gardenin...

in this paper, we prove that the wrapped Butterfly digraph ~ WBF(d; n) of degree d and dimension n contains at least d?1 arc-disjoint Hamilton circuits, answering a conjecture of D. Barth. We also conjecture that ~ WBF(d; n) can be decomposed into d Hamilton circuits, except for {d = 2 and n = 2}, {d = 2 and n = 3} and {d = 3 and n = 2}. We show that it suffices to prove the conjecture for d pr...

The SR algorithm is a structure-preserving algorithm for computing the spectrum of symplectic matrices. Any symplectic matrix can be reduced to symplectic butterfly form. A symplectic matrix B in butterfly form is uniquely determined by 4n− 1 parameters. Using these 4n− 1 parameters, we show how one step of the symplectic SR algorithm for B can be carried out in O(n) arithmetic operations compa...