Directed Assembly of Soft Anisotropic Nanoparticles by Colloid Electrospinning.

Directed assembly of triblock copolymer worms to produce nanostructured fibers is achieved via colloid electrospinning. These copolymer worms are conveniently prepared by polymerization-induced self-assembly in concentrated aqueous dispersion. Addition of a second water-soluble component, poly(vinyl alcohol), is found to be critical for the production of well-defined fibers: trial experiments performed using the worms alone produce only spherical microparticles. Transmission electron microscopy studies confirm that the worm morphology survives electrospinning and the worms become orientated parallel to the main axis of the fibers during their generation. The average deviant angle (θdev ) between the worm orientation and fiber axis decreases from 17° to 9° as the worm/PVA mass ratio increases from 1.15:1 to 5:1, indicating a greater degree of worm alignment within fibers with higher worm contents and smaller fiber diameters. Thus triblock copolymer fibers of ≈300 ± 120 nm diameter can be readily produced that comprise aligned worms on the nanoscale

Fighting their last stand? A global analysis of the distribution and conservation status of gymnosperms

Aim: Gymnosperms are often described as a marginal and threatened group, members of which tend to be out-competed by angiosperms and which therefore preferentially persist at higher latitudes and elevations. The aim of our synthesis was to test these statements by investigating the global latitudinal and elevational distribution of gymnosperms, as well as their conservation status, using all extant gymnosperm groups (cycads, gnetophytes, ginkgophytes and conifers).Location: Worldwide.Methods: We developed a database of 1014 species of gymnosperms containing latitudinal and elevational distribution data, as well as their global conservation status, as described in the literature. The 1014 species comprised 305 cycads, 101 gnetophytes, the only living representative of ginkgophytes, and 607 conifers. Generalized additive models, frequency histograms, kernel density estimations and distribution maps based on Takhtajan's floristic regions were used.Results: Although the diversity of gymnosperms decreases at equatorial latitudes, approximately 50% of the extant species occur primarily between the tropics. More than 43% of gymnosperms can occur at very low elevations (≤ 200 m a.s.l.). Gymnosperms, considering all species together as well as their main taxonomic groups separately, do not exhibit a latitudinal diversity gradient as commonly observed for many other taxa. Gymnosperms, and especially conifers, are on average less threatened at higher and equatorial latitudes.Main conclusions: Gymnosperms display an unusual latitudinal diversity gradient, which we suggest cannot fully be accounted for by angiosperm dominance and competitive superiority. We hypothesize that other factors explain their present distribution, such as the development of centres of endemism in several regions and the adaptation of certain taxa to cold and arid climates

Constructing a biodiversity terminological inventory.

The increasing growth of literature in biodiversity presents challenges to users who need to discover pertinent information in an efficient and timely manner. In response, text mining techniques offer solutions by facilitating the automated discovery of knowledge from large textual data. An important step in text mining is the recognition of concepts via their linguistic realisation, i.e., terms. However, a given concept may be referred to in text using various synonyms or term variants, making search systems likely to overlook documents mentioning less known variants, which are albeit relevant to a query term. Domain-specific terminological resources, which include term variants, synonyms and related terms, are thus important in supporting semantic search over large textual archives. This article describes the use of text mining methods for the automatic construction of a large-scale biodiversity term inventory. The inventory consists of names of species, amongst which naming variations are prevalent. We apply a number of distributional semantic techniques on all of the titles in the Biodiversity Heritage Library, to compute semantic similarity between species names and support the automated construction of the resource. With the construction of our biodiversity term inventory, we demonstrate that distributional semantic models are able to identify semantically similar names that are not yet recorded in existing taxonomies. Such methods can thus be used to update existing taxonomies semi-automatically by deriving semantically related taxonomic names from a text corpus and allowing expert curators to validate them. We also evaluate our inventory as a means to improve search by facilitating automatic query expansion. Specifically, we developed a visual search interface that suggests semantically related species names, which are available in our inventory but not always in other repositories, to incorporate into the search query. An assessment of the interface by domain experts reveals that our query expansion based on related names is useful for increasing the number of relevant documents retrieved. Its exploitation can benefit both users and developers of search engines and text mining applications

No biotic homogenisation across decades but consistent effects of landscape position and pH on macrophyte communities in boreal lakes

It has been predicted that spatial beta diversity shows a decreasing trend in the Anthropocene due to increasing human impact, causing biotic homogenisation. We aimed to discover if vascular aquatic macrophyte communities show different spatial patterns in beta diversity in relation to land use and environmental characteristics in different decades from 1940s to 2010s. We aimed to discover if spatial structures differ between species-, phylogeny- and functional-based beta diversity. We used presence–absence data of aquatic macrophytes from five decades from small boreal lakes. We utilized generalised dissimilarity modelling to analyse spatial patterns in beta diversity in relation to environmental gradients. We found that lake elevation and pH were the most important variables in each decade, while land use was not particularly important in shaping beta diversity patterns. We did not find signs of a decreasing trend in spatial beta diversity in our study area during the past 70 yr. We did not find signs of either biotic homogenisation or biotic differentiation (taxonomic, phylogenetic or functional). Vascular aquatic macrophyte communities showed only slightly different beta diversity patterns in relation to human impact across decades. The patterns of different facets of beta diversity diverged only slightly from each other. Lake position in the landscape, reflecting both natural connectivity and lake characteristics, explained the patterns found in beta diversity, probably because our study area has faced only modest changes in land use from 1940s to 2010s when compared globally. Our study highlights the fact that biotic homogenisation is not an unambiguous process acting similarly at all spatial and temporal scales or in different environments and different organism groups