In many areas across Siberia, the reindeer herding economy of the native people went into a deep recession during the post-Soviet transition of the 1990s. However, as a larger cross-section of data indicates, the reindeer stock decline is not a universal phenomenon. Nor is the present-day crisis in native Siberian herding economies an unprecedented event, as pastoralists did suffer tremendously...

Aim North America harbours the most diverse freshwater mussel fauna on Earth. This fauna has high endemism at the continental scale and within individual river systems. Previous faunal classifications for North America were based on intuitive, subjective assessments of species distributions, primarily the occurrence of endemic species, and do not portray continent-wide patterns of faunal simila...

Here, I address two other problems raised by this article. A review of published experimental results led the authors to conclude that “diversity enhanced ecosystem stability”, where this is defined as “the ability to withstand recurrent perturbations”. This curious statement reverses modern theory of ecological diversity in the ocean as discussed, for instance, by Ramón Margalef. Ecosystems of...

The recommendation algorithm based on bipartite network is superior to traditional methods on accuracy and diversity, which proves that considering the network topology of recommendation systems could help us to improve recommendation results. However, existing algorithms mainly focus on the overall topology structure and those local characteristics could also play an important role in collabor...

A new way into the ER Membrane-embedded proteins are highly diverse in topology, physical characteristics, and location. This diversity necessitates multiple pathways for their effective membrane insertion. Guna et al. found that a widely conserved protein complex is responsible for inserting a subset of membrane proteins into the endoplasmic reticulum (ER) membrane (see the Perspective by Fry ...

We define a utility-based framework for joint channel assignment and topology control in multi-rate multi-radio wireless mesh networks, and present a greedy algorithm for solving the corresponding optimization problem. The proposed approach can support different target objectives, which are expressed as utility functions of the end-to-end throughput from the gateways to the mesh nodes. The latt...

Topology optimization has been an interesting area of research in recent years.  The main focus of this paper is to use an evolutionary swarm intelligence algorithm to perform Isogeometric Topology optimization of continuum structures.  A two-dimensional plate is analyzed statically and the nodal displacements are calculated.  The nodal displacements using Isogeometric analysis are found to be ...

in this paper we investigate generalized topologies generated by a subbase ofpreorder relators and consider its application in the concept of the complement. we introducethe notion of principal generalized topologies obtained from the new type of open sets andstudy some of their important properties.