For the mean curvature vector field H and the Laplace operator ∆ of a submanifold in the Minkowski space, a submanifold satisfying the condition ∆H = f H + gC is known as a generalized null 2-type, where f and g are smooth functions, and C is a constant vector. The notion of generalized null 2-type submanifolds is a generalization of null 2-type submanifolds defined by B.-Y. Chen. In this paper...

Animal models of colitis, which develop dysplasia and cancer similar to human ulcerative colitis are needed to further investigate the dysplasia cancer sequence. This study describes the expression of B-catenin and p53 along with the histopathology and inflammation scores as they relate to dysplasia and cancer in the dextran sulfate sodium (DSS) colitis model. Swiss Webster mice were fed with 5...

This note arises from an attempt to give some model-theoretic interpretation of the concept of flatness. It is well-known that a necessary condition for a ring morphism A → B to be faithfully flat, is that any linear system of equations with coefficients from A which has a solution over B, must have already a solution over A. In fact, if we strenghten this condition to any solution over B comes...

introduction: flat foot is one of the most common disorders which not only influences the performance of the foot, but also affects the alignments of the ankle, knee and hip joints. the performance of flat arched differs from that of normal subjects during walking. however, there is not enough information in the literature regarding the difference between standing stability. moreover, the influ...

In 2001, S. Bulman-Fleming et al. initiated the study of three flatness properties (weakly kernel flat, principally weakly kernel flat, translation kernel flat) of right acts $A_{S}$ over a monoid $S$ that can be described by means of when the functor $A_{S} otimes -$ preserves pullbacks. In this paper, we extend these results to $S$-posets and present equivalent descriptions of weakly kernel p...

This paper proposes several nonlinear control strategies for trajectory trackingof a quadcopter system based on the property of differential flatness. Its origi-nality is twofold. Firstly, it provides a flat output for the quadcopter dynamicscapable of creating full flat parametrization of the states and inputs. Moreover,B-splines characterizations of the flat output and the...

objectives: the aim of this study was to determine the prevalence of flat foot in a population of 7-12 year old students and to investigate the relationship between flat foot and age and sex. methods: in this cross-sectional study, a total of 945 students (460 girls and 485 boys) were examined. the presence of flatfoot and the degree of its severity according to tachdjian's system of gradi...

All Lorentzian tori with a non-discrete group of isometries are characterized and explicitly obtained. They can lie into three cases: (a) flat, (b) conformally flat but non-flat, and (c) geodesically incomplete. A detailed study of many of their properties (including results on the logical dependence of the three kinds of causal completeness, on geodesic connectedness and on prescribed curvatur...