Genetic Investigation Into the Diversity and Population Structure of Penstemon harringtonii (Harrington\u27s Beardtongue)

Penstemon harringtonii is an endemic Colorado species that is listed on Bureau of Land Management (BLM) State Director’s Sensitive Species List as well as on the U.S. Forest Service sensitive species list. Penstemon harringtonii is encountering threats from habitat destruction and fragmentation due to oil and gas exploration, livestock grazing and recreational activities. Penstemon harringtonii is scattered across six counties in north central Colorado. The populations split into three general areas, one around Eagle and north to Kremmling, from Glenwood Spring south to Aspen and around the community of Rifle. The disjunct nature of the species has raised questions related to the amount of genetic diversity throughout the range, population structure dynamics and rates of gene flow among populations and regions. Individuals from 20 populations of P. harringtonii and 6 populations of Penstemon osterhoutii were collected from wild populations. Additional samples of P. osterhoutii, P. cyathophorus, P. secundiflorus, and P. angustiflolius were taken from herbarium specimens or live collections in botanic gardens. Microsatellite analysis was completed using 9 variable loci to determine genetic diversity, rates of gene flow and population structure of P. harringtonii. Chloroplast DNA analysis was completed using three intergenic regions to determine haplotype diversity, phylogenetic relationships and patterns of maternal gene flow. These analysis showed that P. harringtonii is distinct from P. osterhoutii. Three distinct genetic groups are present in P. harringtonii: Rifle, Roaring Fork River Valley and East of Glenwood Canyon. High levels genetic diversity are present with exceptional level of gene flow between genetic groups, which is great enough to maintain a cohesive species across the entire range. Inbreeding levels were low, posing minimal concern. Two population of P. harringtonii were found to be quite distinct at the northern and southern extents of the population when compared to the region genetic groups. Conservation and land management agencies now have genetic information that can be utilized to inform decisions about the conservations of P. harringtonii

Transport Properties of Highly Aligned Polymer Light-Emitting-Diodes

We investigate hole transport in polymer light-emitting-diodes in which the emissive layer is made of liquid-crystalline polymer chains aligned perpendicular to the direction of transport. Calculations of the current as a function of time via a random-walk model show excellent qualitative agreement with experiments conducted on electroluminescent polyfluorene demonstrating non-dispersive hole transport. The current exhibits a constant plateau as the charge carriers move with a time-independent drift velocity, followed by a long tail when they reach the collecting electrode. Variation of the parameters within the model allows the investigation of the transition from non-dispersive to dispersive transport in highly aligned polymers. It turns out that large inter-chain hopping is required for non-dispersive hole transport and that structural disorder obstructs the propagation of holes through the polymer film.Comment: 4 pages, 5 figure

Temperature and Field Dependence of the Mobility in Liquid-Crystalline Conjugated Polymer Films

The transport properties of organic light-emitting diodes in which the emissive layer is composed of conjugated polymers in the liquid-crystalline phase have been investigated. We have performed simulations of the current transient response to an illumination pulse via the Monte Carlo approach, and from the transit times we have extracted the mobility of the charge carriers as a function of both the electric field and the temperature. The transport properties of such films are different from their disordered counterparts, with charge carrier mobilities exhibiting only a weak dependence on both the electric field and temperature. We show that for spatially ordered polymer films, this weak dependence arises for thermal energy being comparable to the energetic disorder, due to the combined effect of the electrostatic and thermal energies. The inclusion of spatial disorder, on the other hand, does not alter the qualitative behaviour of the mobility, but results in decreasing its absolute value.Comment: 9 pages, 8 figures, submitted to Phys. Rev.

Impact of contamination on the development of controlled inundation areas along the Scheldt estuary (poster)

One of the objectives of the SIGMA-plan of the River Scheldt is the construction of a controlled inundation area in Kruibeke-Bazel-Rupelmonde. However this area is contaminated with heavy metals due to aerial deposition. On the other hand, as an inundation area, it will be flooded with contaminated water from the Scheldt. Therefore it is necessary to estimate the impact of contamination on the potential nature development in these areas.A case study was carried out last two years in a VLINA-project at a tidal marsh along the River Scheldt. The distribution of the contaminants over the different compartments was investigated during two years. The compartments were the soil and pore water, but also the vegetation and the dominant group of macrobenthos. Beside this an estimation was made of the input of contaminants due to the sedimentation of particles during flooding. Other processes that were studied are the sorption and desorption processes, which affect the bioavailability, and the effect on the uptake of contaminants and the bioaccumulation in reed (Phragmites australis) and Oligochaeta are studied in detail. The above- and belowground biomass of reed (Phragmites australis) was measured

Literacy practices of primary education children in Andalusia (Spain): a family-based perspective

Primary school children develop literacy practices in various domains and situations in everyday life. This study focused on the analysis of literacy practices of children aged 8–12 years from the perspec- tive of their families. 1,843 families participated in the non-experimental explanatory study. The children in these families speak Spanish as a first language and are schooled in this language. The instrument used was a self-report questionnaire about children’s home-literacy practices. The data obtained were analysed using categorical principal components analysis (CATPCA) and analysis of variance (ANOVA). The results show the complex relationship between literacy practices developed by children in the domains of home and school and the limited development of a literacy-promoting ‘third space’. In conclusion, the families in our study had limited awareness of their role as literacy- promoting agents and thought of literacy learning as restricted to formal or academic spaces

Revealing natural relationships among arbuscular mycorrhizal fungi: culture line BEG47 represents Diversispora epigaea, not Glomus versiforme

Background: Understanding the mechanisms underlying biological phenomena, such as evolutionarily conservative trait inheritance, is predicated on knowledge of the natural relationships among organisms. However, despite their enormous ecological significance, many of the ubiquitous soil inhabiting and plant symbiotic arbuscular mycorrhizal fungi (AMF, phylum Glomeromycota) are incorrectly classified. Methodology/Principal Findings: Here, we focused on a frequently used model AMF registered as culture BEG47. This fungus is a descendent of the ex-type culture-lineage of Glomus epigaeum, which in 1983 was synonymised with Glomus versiforme. It has since then been used as ‘G. versiforme BEG47’. We show by morphological comparisons, based on type material, collected 1860–61, of G. versiforme and on type material and living ex-type cultures of G. epigaeum, that these two AMF species cannot be conspecific, and by molecular phylogenetics that BEG47 is a member of the genus Diversispora. Conclusions: This study highlights that experimental works published during the last >25 years on an AMF named ‘G. versiforme’ or ‘BEG47’ refer to D. epigaea, a species that is actually evolutionarily separated by hundreds of millions of years from all members of the genera in the Glomerales and thus from most other commonly used AMF ‘laboratory strains’. Detailed redescriptions substantiate the renaming of G. epigaeum (BEG47) as D. epigaea, positioning it systematically in the order Diversisporales, thus enabling an evolutionary understanding of genetical, physiological, and ecological traits, relative to those of other AMF. Diversispora epigaea is widely cultured as a laboratory strain of AMF, whereas G. versiforme appears not to have been cultured nor found in the field since its original description

Molecular diversity of arbuscular mycorrhizal fungi and patterns of host association over time and space in a tropical forest

We have used molecular techniques to investigate the diversity and distribution of the arbuscular mycorrhizal (AM) fungi colonizing tree seedling roots in the tropical forest on Barro Colorado Island (BCI), Republic of Panama. In the first year, we sampled newly emergent seedlings of the understory treelet Faramea occidentalis and the canopy emergent Tetragastris panamensis, from mixed seedling carpets at each of two sites. The following year we sampled surviving seedlings from these cohorts. The roots of 48 plants were analysed using AM fungal-specific primers to amplify and clone partial small subunit (SSU) ribosomal RNA gene sequences. Over 1300 clones were screened for random fragment length polymorphism (RFLP) variation and 7% of these were sequenced. Compared with AM fungal communities sampled from temperate habitats using the same method, the overall diversity was high, with a total of 30 AM fungal types identified. Seventeen of these types have not been recorded previously, with the remainder being similar to types reported from temperate habitats. The tropical mycorrhizal population showed significant spatial heterogeneity and nonrandom associations with the different hosts. Moreover there was a strong shift in the mycorrhizal communities over time. AM fungal types that were dominant in the newly germinated seedlings were almost entirely replaced by previously rare types in the surviving seedlings the following year. The high diversity and huge variation detected across time points, sites and hosts, implies that the AM fungal types are ecologically distinct and thus may have the potential to influence recruitment and host composition in tropical forests

Facilitating new forms of discourse for learning and teaching: harnessing the power of Web 2.0 practices

When asked what they would find most helpful to enable them to use technologies more in their teaching, most teachers say "give me examples, in my subject area" and "point me to relevant people I can discuss these issues with". Web 2.0 technologies - with their emphasis on sharing, networking and user production - seem to offer a potential solution. However uptake and use of web 2.0 sites such as blogs, social networking and wikis by teachers for sharing and discussing practice has being marginal so far. This paper focuses on work we are undertaking as part of the OU Learning Design Initiative (http://ouldi.open.ac.uk) and the Hewlett-funded Olnet initiative (http://olnet.org). A key focus of our work is the development of tools, methods and approaches to support the design of innovative learning activities and Open Educational Resources (OER). In this paper I want to focus on one strand of our work; namely how to leverage technologies to promote better sharing and discussing of learning and teaching ideas and designs

Retinal glycoprotein enrichment by concanavalin a enabled identification of novel membrane autoantigen synaptotagmin-1 in equine recurrent uveitis.

Complete knowledge of autoantigen spectra is crucial for understanding pathomechanisms of autoimmune diseases like equine recurrent uveitis (ERU), a spontaneous model for human autoimmune uveitis. While several ERU autoantigens were identified previously, no membrane protein was found so far. As there is a great overlap between glycoproteins and membrane proteins, the aim of this study was to test whether pre-enrichment of retinal glycoproteins by ConA affinity is an effective tool to detect autoantigen candidates among membrane proteins. In 1D Western blots, the glycoprotein preparation allowed detection of IgG reactions to low abundant proteins in sera of ERU patients. Synaptotagmin-1, a Ca2+-sensing protein in synaptic vesicles, was identified as autoantigen candidate from the pre-enriched glycoprotein fraction by mass spectrometry and was validated as a highly prevalent autoantigen by enzyme-linked immunosorbent assay. Analysis of Syt1 expression in retinas of ERU cases showed a downregulation in the majority of ERU affected retinas to 24%. Results pointed to a dysregulation of retinal neurotransmitter release in ERU. Identification of synaptotagmin-1, the first cell membrane associated autoantigen in this spontaneous autoimmune disease, demonstrated that examination of tissue fractions can lead to the discovery of previously undetected novel autoantigens. Further experiments will address its role in ERU pathology