Since exact determination of haplotype blocks is usually not possible, it is desirable to develop a haplotyping method which can account for recombinations. A natural candidate for such a method is haplotyping via phylogenetic networks or their simplified version: galled-tree networks. In earlier work we characterized the existence of the galled-tree networks. Building on this, we reduce the problem of haplotype inferring via galled-tree networks to a hypergraph covering problem for genotype matrices satisfying a combinatorial condition. Our experiments on actual data show that this condition is almost always satisfied when the percentage of minor alleles for each SNP reaches at least 30%. 相似文献
Let p be an odd prime and qp(a)=(ap−1−1)/p be the Fermat quotient with base a, p?a. The main purpose of this paper is to investigate the fourth power problem of qp(2) and deduce an explicit formula represented by a linear combination of Mirimanoff polynomial values. 相似文献
In contrast to former morphological studies, the results presented here show that calcium(II) thiosulfate hexahydrate, CaS2O3·6H2O, crystallizes centrosymmetrically in the pinacoidal class (point group ). The structure is characterized by chains, parallel to [100], of alternating S2O3 and Ca(H2O)6O2 groups sharing common O atoms. The composition of each chain link is [Ca(H2O)6(S2O3)]. The geometry is analysed and compared in detail with the structural features of monoclinic strontium(II) thiosulfate pentahydrate, SrS2O3·5H2O, which forms layers, parallel to (100), of alternating S2O3 and Sr(H2O)4O5 groups connected via common O atoms and O–O edges. Each layer contains [Sr(H2O)3O(S2O3)]∞ as the unique repeat unit. 相似文献
The crystal structures of three compounds of glycine and inorganic materials are presented and discussed. The orthorhombic structure of glycinesulfatodilithium(I), [Li2(SO4)(C2H5NO2)]n, consists of corrugated sheets of [LiO4] and [SO4] tetrahedra. The glycine molecules are located between these sheets. The main features of the monoclinic structure of diaquadichloroglycinenickel(II), [NiCl2(C2H5NO2)(H2O)2]n, are helical chains of [NiO4Cl2] octahedra connected by glycine molecules. The orthorhombic structure of triaquaglycinesulfatozinc(II), [Zn(SO4)(C2H5NO2)(H2O)3]n, is made up of [O3SOZnO5] clusters. These clusters are linked by glycine molecules into zigzag chains. All three compounds are examples of non‐centrosymmetric glycine compounds. 相似文献
We consider a general two-component plasma of classical pointlike charges \(+e\) (e is say the elementary charge) and \(-Z e\) (valency \(Z=1,2,\ldots \)), living on the surface of a sphere of radius R. The system is in thermal equilibrium at the inverse temperature \(\beta \), in the stability region against collapse of oppositely charged particle pairs \(\beta e^2 < 2/Z\). We study the effect of the system excess charge Qe on the finite-size expansion of the (dimensionless) grand potential \(\beta \varOmega \). By combining the stereographic projection of the sphere onto an infinite plane, the linear response theory and the planar results for the second moments of the species density correlation functions we show that for any \(\beta e^2 < 2/Z\) the large-R expansion of the grand potential is of the form \(\beta \varOmega \sim A_V R^2 + \left[ \chi /6 - \beta (Qe)^2/2\right] \ln R\), where \(A_V\) is the non-universal coefficient of the volume (bulk) part and the Euler number of the sphere \(\chi =2\). The same formula, containing also a non-universal surface term proportional to R, was obtained previously for the disc domain (\(\chi =1\)), in the case of the symmetric \((Z=1)\) two-component plasma at the collapse point \(\beta e^2=2\) and the jellium model \((Z\rightarrow 0)\) of identical e-charges in a fixed neutralizing background charge density at any coupling \(\beta e^2\) being an even integer. Our result thus indicates that the prefactor to the logarithmic finite-size expansion does not depend on the composition of the Coulomb fluid and its non-universal part \(-\beta (Qe)^2/2\) is independent of the geometry of the confining domain. 相似文献
Thermodynamic potential of a neutral two-dimensional (2D) Coulomb fluid, confined to a large domain with a smooth boundary, exhibits at any (inverse) temperature \(\beta \) a logarithmic finite-size correction term whose universal prefactor depends only on the Euler number of the domain and the conformal anomaly number \(c=-1\). A minimal free boson conformal field theory, which is equivalent to the 2D symmetric two-component plasma of elementary \(\pm e\) charges at coupling constant \(\Gamma =\beta e^2\), was studied in the past. It was shown that creating a non-neutrality by spreading out a charge Qe at infinity modifies the anomaly number to \(c(Q,\Gamma ) = - 1 + 3\Gamma Q^2\). Here, we study the effect of non-neutrality on the finite-size expansion of the free energy for another Coulomb fluid, namely the 2D one-component plasma (jellium) composed of identical pointlike e-charges in a homogeneous background surface charge density. For the disk geometry of the confining domain we find that the non-neutrality induces the same change of the anomaly number in the finite-size expansion. We derive this result first at the free-fermion coupling \(\Gamma \equiv \beta e^2=2\) and then, by using a mapping of the 2D one-component plasma onto an anticommuting field theory formulated on a chain, for an arbitrary even coupling constant. 相似文献
The non‐centrosymmetric polar tetragonal (P 41) barium antimony tartrate trihydrate, Ba[Sb2((+)C4H2O6)2]·3H2O, was found to be an attractive novel semi‐organic crystal manifesting numerous χ (2)‐ and χ (3)‐nonlinear optical interactions. In particular, with picosecond single‐ and dual‐wavelength pumping SHG and THG via cascaded parametric four‐wave processes were observed. High‐order Stokes and anti‐Stokes lasing related to two SRS‐promoting vibration modes of the crystal, with ωSRS1 ≈ 575 cm?1 and ωSRS2 ≈ 2940 cm?1, takes place. Basing on a spontaneous Raman investigation an assignment of the two SRS‐active vibration modes is discussed.
This paper deals with analytical modelling of thermal stresses in a multi-particle-matrix system with isotropic spherical
particles. These particles are periodically distributed in an isotropic infinite matrix. This model system which is characterized
by microstructural parameters (particle volume fraction, particle radius) is applicable to two-phase composites of a precipitate-matrix
type with isotropic phases. The thermal stresses originate during a cooling process due to a difference in thermal expansion
coefficients. The analytical modelling which is based on fundamental equations of solid continuum mechanics represents a combination
of different mathematical procedures applied to equilibrium and compatibility equations. This novel analytical model is compared
with that which is based on mathematical procedures applied to the equilibrium equations only. The energy analysis of both
analytical models which is applied to the SiC-Al2O3 composite is presented. 相似文献