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This paper focuses on the global existence for a class of Keller-Segel models with signal-dependent motility and general logistic term under homogeneous Neumann boundary conditions in a two-dimensional smoothly bounded domain. We show that if λ ∈ R, μ > 0 and l > 2 are constants, then for all sufficiently smooth initial data the system {ut = Δ(γ(v)u) + λu − μul, x ∈ Ω, t > 0, vt = Δv − v + u, x ∈ Ω, t > 0, possesses a global classical solution. [ABSTRACT FROM AUTHOR]

To talk about Prof. Dr. Heinz Dieter Heidemann it is needed to establish a two dimensions life journey: As a drifter, his intrinsic alien condition, and his Passion for Guimarães Rosa´s literature. Small and large details show his uniqueness. Even though he´d embraced a diversity of disciplines, his passion has always been the subject of Migration. He was a steady driffer, but once he had always moved, since childhood he felt the pain of those who are moved by the greed of capital. The matching point of his thinking echoes in Robert Kurz's analytical writings: enabling a differentiated thinking by the radical critique of the negation of any enlightening emancipatory perspective of modernity. Dieter Heidemann have exposes the criticism the Utopian Enlightenment vision of the emancipatory character of the State in all his publications. What is most passionate about him is the ability to be and think is own condition of the different, with several eminences that indicate his uniqueness, arousing the desire of knowing him.

Zooplankton assemblages in neighboring ponds can show important spatial and temporal heterogeneity. Disentangling the influence of regional versus local factors, and of deterministic versus stochastic processes has been recently highlighted in the context of the metacommunity theory. In this study, we determined patterns of temporal and spatial variation in zooplankton diversity along one hydrological year in restored ponds of different hydroperiod and age. The following hypotheses regarding the assembling of species over time were tested: i) dispersal is not limited in our study system due to its small area and high exposure to dispersal vectors; ii) community dissimilarity among ponds increases with restoration age due to an increase in environmental heterogeneity and stronger niche-based assemblages;and iii) similarity increases with decreasing hydroperiod because hydroperiod is a strong selective force filtering out organisms with long life cycles. Our results confirmed dispersal as a homogenizing force and local factors as gaining importance with time of restoration. However, short hydroperiod ponds were highly dissimilar, maybe due to the environmental differences among these ponds, or to high stochasticity followed by priority effects under a weak selection pressure. By adding a temporal dimension to the study of zooplankton structuring, we could identify the first months after flooding as being crucial for species richness, especially in short hydroperiod ponds; and we detected differences in seasonal species richness related to hydroperiod and pond age.

In this paper, we discuss the existence, nonexistence, and multiplicity of positive solutions for a class of singular eigenvalue problems. Some of our theorems are new, while others extend earlier results obtained by Zhang and Kong [12]. The interesting point is that the authors obtain the relation between the existence of solutions and the parameter $lambda$. The arguments are based on the fixed point index theory and the upper and lower solutions method.

This paper deals with a particular family of lower mobility parallel kinematic manipulators. The four degrees of freedom of the end-effector consist of three translations plus one rotation with a high tilting angle. Robots belonging to this family are first introduced, and a common parameterization is established. Then an extended kinematic model is proposed for this family of robots using a new Jacobian matrix. Relevant information about robot kinematic singularities, internal singularities, and possible end-effector motions can be obtained by resorting to this matrix. The efficiency of this method is proven by applying it to several traveling-plate architectures corresponding to already built robot prototypes. The results of the expected behavior are compared with the prototype's real behavior. The goal of this paper is to show that internal (or constraint) singularites can occur in lower mobility parallel kinematic manipulators, and to underline the influence they have during the design stage. [ABSTRACT FROM AUTHOR]

This paper aims at exploring the harmony between theism and the basic paradigm of the so-called "big bang theory", which has been sustained for explaining the existence of the universe, by claiming that big bang theory supported theistic arguments in a new and powerful manner. In this context, the paper will discuss the relationship between the- ism and big bang theory. [ABSTRACT FROM AUTHOR]

In regard to the characterization of the disturbances in autist's utterances, their "echo" nature has been highlighted in several studies so far carried out in the area, that is, the repetition of words the same way as they are heard. Nevertheless, estereotypy, rigidity or immobility aspects have been enhanced, in such repetitions which bring about a strangeness died in the listener representing, therefore, a singularity trait in the symptomatology of verbal nature in autism. In that sense, the present article puts into discussion the recognition of such singularity, comparing it with the provoked effects (in lhe investigator) by the utterances, also singular, produced by the child who does not present disturbances in his/her linguistic course. Based on such a comparison, some points were raised, suggesting that the recognition of the singularity of the autist's echolalia would hapen by inverse means to the recognition of the singular character of the subject's speech, at the beginning of his/her language acquisition course. [ABSTRACT FROM AUTHOR]

The viscous incompressible flow in a wedge between a rigid plane and a surface of constant shear stress is calculated by use of the Mellin transform. For wedge angles below a critical value the asymptotic solution near the vertex is given by a local similarity solution. The respective stream function grows quadratically with the distance from the origin. For supercritical wedge angles the similarity solution breaks down and the leading order solution for the stream function grows with a power law having an exponent less than two. At the critical angle logarithmic terms appear in the stream function. The asymptotic dependence of the stream function found here is the same as for the 'hinged plate' problem. It is shown that the validity of the Stokes flow assumption is restricted to a vanishingly small distance from the vertex when the wedge angle is above critical and when the region of nonzero constant shear stress is extended to infinity. The relevance of the present result for technical flow systems is pointed out by comparison with the numerically calculated flow in a thermocapillary liquid bridge. [ABSTRACT FROM AUTHOR]