Background: In order to transfer teachers’ knowledge, the presence of students is necessary in the classroom. Despite numerous studies on the causes of absence, the strategies of its reduction have not been yet investigated and this study intends to address this issue. Methods: Inthis cross-sectional study 401 students were participated who were selected with systematic random sampling. The stu...

We describe the structure of those locally finite varieties whose first order theory is decidable. A variety is a class of universal algebras defined by a set of equations. Such a class is said to be locally finite if every finitely generated member of the class is finite. It turns out that in order for such a variety to have a decidable theory it must decompose into the varietal product of thr...

BACKGROUND Previous research has shown that environments with features that encourage walking are associated with increased physical activity. Existing methods to assess the built environment using geographical information systems (GIS) data, direct audit or large surveys of the residents face constraints, such as data availability and comparability, when used to study communities in countries ...

We express the Chern-Schwartz-MacPherson class of a possibly singular variety in terms of the total Chern class of a bundle of di erential forms with logarithmic poles. As an application, we obtain a formula for the Chern-Schwartz-MacPherson class of a hypersurface of a nonsingular variety, in terms of the Chern-Mather class of a suitable sheaf. x

We study the action of the mapping class groupMod(S) on the boundary ∂Q of quasifuchsian space Q. Among other results, Mod(S) is shown to be topologically transitive on the subset C ⊂ ∂Q of manifolds without a conformally compact end. We also prove that any open subset of the character varietyX (π1(S),PSL2 C) intersecting ∂Q does not admit a nonconstant Mod(S)-invariant meromorphic function. Th...

In this paper, a lemma in algebraic coding theory is established, which is frequently appeared in the encoding and decoding for algebraic codes such as Reed–Solomon codes and algebraic geometry codes. This lemma states that two vector spaces, one corresponds to information symbols and the other is indexed by the support of Gröbner basis, are canonically isomorphic, and moreover, the isomorphism...

The purpose of this paper is to show that the Todd class of a simplicial toric variety has a canonical expression in terms of products of torus-invariant divisors. The coefficients in this expression, which are generalizations of the classical Dedekind sum, are shown to satisfy a reciprocity relation which characterizes them uniquely. We achieve these results by giving an explicit formula for t...

Bio-directed synthesis of nanoparticles is an interesting field of rapid advancement for biologists,chemists and materials scientists, especially in light of efforts to find out green methods of inorganicmaterial synthesis. In the present study, green synthesis of platinum nanoparticles (PtNPs) using sheepmilk is reported for the first time. By adjusti...

The salient, and often ignored, role that out-of-class learning plays in second/foreign language (L2) learners’ development is overshadowed by classroom research. The main aim of this study is to problematize the role of out-of-class learning in the specific English-as-Foreign-Language (EFL) context of Iran by examination of the ways in which four learners attempted to revamp their English lang...

1.1. QCoh on a stack. We know that QCoh forms a stack, i.e., sheaf of groupoids, over Schfpqc(S) for any scheme S. Thus if we have an fpqc sheaf of groupoids X over S, we can define QCoh(X ) as maps of sheaves X → QCoh on Schfpqc(S). By 2-Yoneda, this definition agrees with the usual notion of quasicoherent sheaves if X is a scheme. For various other (usually equivalent) definitions in the case...