Electrophoretic deposition of layer-by-layer unsheathed carbon nanotubes - A step towards steerable surface roughness and wettability

It is well known that carbon nanotube (CNT) oxidation (usually with concentrated HNO3) is a major step before the electrophoretic deposition (EPD). However, the recent discovery of the “onion effect” proves that multiwalled carbon nanotubes are not only oxidized, but a simultaneous unsheathing process occurs. We present the first report concerning the influence of unsheathing on the properties of the thus-formed CNT surface layer. In our study we examine how the process of gradual oxidation/unsheathing of a series of multiwalled carbon nanotubes (MWCNTs) influences the morphology of the surface formed via EPD. Taking a series of well-characterized and gradually oxidized/unsheathing Nanocyl™ MWCNTs and performing EPD on a carbon fiber surface, we analyzed the morphology and wettability of the CNT surfaces. Our results show that the water contact angle could be gradually changed in a wide range (125–163°) and the major property determining its value was the diameter of aggregates formed before the deposition process in the solvent. Based on the obtained results we determined the parameters having a crucial influence on the morphology of created layers. Our results shed new light on the deposition mechanism and enable the preparation of surfaces with steerable roughness and wettability

Glacial refugia and migration routes of the Neotropical genus Trizeuxis (Orchidaceae)

The morphology and anatomy of the monotypic genus Trizeuxis make this taxon almost impossible to recognize in fossil material and hereby difficult object of historical geographic studies. To estimate the distribution of potential refugia during the last glacial maximum and migration routes for Trizeuxis the ecological niche modeling was performed. The potential niche modeling was done using maximum entropy method implemented in Maxent application based on the species presence-only observations. As input data climatic variables and the digital elevation model were used. Two models of suitable glacial habitats distribution were prepared – for the studied species and for its host. The compiled map of the suitable habitats distribution of T. falcata and P. guajava during the last glacial maximum (LGM) indicate two possible refugia for the studied orchid genus. The first one was located in the Madre de Dios region and the other one in the Mosquito Coast. The models suggest the existence of two migration routes of Trizeuxis species. The results indicate that the ecological niche modeling (ENM) is a useful tool for analyzing not only the possible past distribution of the species, but may be also applied to determine the migration routes of the organisms not found in the fossil material

Niche conservatism of Eulophia alta, a trans-Atlantic orchid species

The genus Eulophia embraces over 230 species distributed through the tropical and subtropical Africa, Asia, Australia and the Americas. In Neotropics it is represented by a sole species – E. alta. The aim of the presented study was to evaluate the difference between ecological niches occupied by American and African populations of this species based on the ecological niche modeling. The similarity between the glacial and present niches occupied by E. alta was calculated and the factors limiting the species occurrence were identified. Areas of seasonal tropical forest, tropical savanna and woodland served as refugia for the studied species during last glacial maximum and they were more widespread in Neotropics than in Africa. No significant niche shift after last glacial maximum was observed. The distribution of E. alta in its whole range is restricted mainly by temperature seasonality. The differences in the niches occupied by African and Neotropical populations of E. alta suggest preglacial disjunction of the species range and independent adaptation of both groups. Despite the significant range disjunction of E. alta the species is characterized by relatively high degree of niche conservatism

The naturalization status of African Spotted Orchid (<i>Oeceoclades maculata</i>) in Neotropics

<div><p>Naturalization status of the African orchid introduced in the Neotropics, <i>Oeceoclades maculata</i>, was studied. Ecological niche modeling was applied to estimate the present distribution of the suitable habitats for the African Spotted Orchid. The similarity of the niches occupied by natural and invasive populations of the studied species was calculated. Moreover, future distribution of its suitable habitats was estimated on the basis of three different climatic change scenarios, and the potential further expansion scale was calculated based on range overlap test. Although currently <i>O. maculata</i> seems to have reached its potential limits of invasion in South America and as for now it should not spread to the new habitats, the species still has a potential of invasiveness in North America. The future climate changes will probably result in shifts in the distribution of African Spotted Orchid suitable niches thereby causing its expansion to the new areas.</p></div

Orobanche laxissima and its host plants records

Database of localities of parasitic Orobanche laxissima and its host plantsTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Herbarium-based studies on taxonomy, biogeography and ecology of Psilochilus (Orchidaceae)

Background Psilochilus is a poorly studied orchid genus distributed from southern Mexico to south-eastern Brazil. A taxonomic revision of this Neotropical endemic based on morphological data is presented. Material and Methods Over 170 dried herbarium specimens and flowers preserved in liquid of Psilochilus were analyzed. Morphological variation among examined taxa was described based on multivariate analysis. To evaluate the similarity between niches occupied by various Psilochilus species ecological niche modeling (ENM) was applied. Species richness and the distribution patterns of Psilochilus representatives were analyzed based on squares of 5° latitude and longitude while similarities among floras between biogeographical units were measured using the Bray-Curtis index for presence/absence data. Results and Discussion A new species of the P. physurifolius-complex is described based on Central American material. Psilochilus crenatifolius is reduced to the rank of variety as P. macrophyllus var. crenatifolius. A key to 18 accepted Psilochilus species is provided. The illustrations of perianth segments of all recognized taxa are presented. The climatic niches preferred by the particular Psilochilus representatives are well separated based on ecological niche modeling analysis. Their distribution is limited mainly by the isothermality and temperature seasonality. The highest Psilochilus species richness is observed in the North Andean, Panamanian, Brazilian Planalto and Central American biogeographical provinces. A high level of endemism is observed in all those regions as well as Yungas biogeographical province. Most Psilochilus species occur in areas above 800 m of elevation. The populations were most often reported from the tropical rain forest and tropical moist deciduous forest

The coverage [km²] of the most suitable habitats for <i>Dactylorhiza</i> representatives (suitability of over 0.7) at present time and in 2080 (A1b, A2a, B2a) in Europe and Asia.

<p>^a CCCMA-CGCM3 climate change simulation for 2080</p><p>^b CCCMA-CGCM2 climate change simulation for 2080</p><p>^c CCCMA-CGCM2 climate change simulation for 2080</p><p>The coverage [km²] of the most suitable habitats for <i>Dactylorhiza</i> representatives (suitability of over 0.7) at present time and in 2080 (A1b, A2a, B2a) in Europe and Asia.</p

Glacial Refugia and Future Habitat Coverage of Selected <i>Dactylorhiza</i> Representatives (Orchidaceae)

<div><p>The intensively discussed taxonomic complexity of the <i>Dactylorhiza</i> genus is probably correlated with its migration history during glaciations and interglacial periods. Previous studies on past processes affecting the current distribution of <i>Dactylorhiza</i> species as well as the history of the polyploid complex formation were based only on molecular data. In the present study the ecological niche modeling (ENM) technique was applied in order to describe the distribution of potential refugia for the selected <i>Dactylorhiza</i> representatives during the Last Glacial Maximum. Additionally, future changes in their potential habitat coverage were measured with regard to three various climatic change scenarios. The maximum entropy method was used to create models of suitable niche distribution. A database of <i>Dactylorhiza</i> localities was prepared on the grounds of information collected from literature and data gathered during field works. Our research indicated that the habitats of majority of the studied taxa will decrease by 2080, except for <i>D</i>. <i>incarnata</i> var. <i>incarnata</i>, for which suitable habitats will increase almost two-fold in the global scale. Moreover, the potential habitats of some taxa are located outside their currently known geographical ranges, e.g. the Aleutian Islands, the western slopes of the Rocky Mountains, Newfoundland, southern Greenland and Iceland. ENM analysis did not confirm that the Balkans, central Europe or central Russia served as the most important refugia for individual representatives of the <i>Dactylorhiza incarnata/maculata</i> complex. Our study rather indicated that the Black Sea coast, southern Apennines and Corsica were the main areas characterized by habitats suitable for most of the taxa.</p></div

Current distribution of suitable niches of <i>D</i>. <i>majalis</i> ssp. <i>lapponica</i> (A), <i>D</i>. <i>majalis</i> ssp. <i>majalis</i> (B), and <i>D</i>. <i>majalis</i> ssp. <i>traunsteineri</i> (C).

<p>Current distribution of suitable niches of <i>D</i>. <i>majalis</i> ssp. <i>lapponica</i> (A), <i>D</i>. <i>majalis</i> ssp. <i>majalis</i> (B), and <i>D</i>. <i>majalis</i> ssp. <i>traunsteineri</i> (C).</p