Reassessment of the invasion history of two species of Cakile (Brassicaceae) in Australia

In this paper we revisit the invasion history of two species of Cakile in Australia. Cakile edentula subsp. edentula arrived in the mid 19th Century and spread into coastal strandline habitat from the southeast towards the west and to the north; Cakile maritima arrived in the late 19th Century and has replaced Cakile edentula over much of the range. While Cakile edentula is morphologically quite uniform, the great variation within Cakile maritima has confused field ecologists. Using herbarium records we update previous accounts of the spread of the species and report on field surveys that determined their current geographic overlap in Tasmania and in northern New South Wales/southern Queensland. We examine regional morphological variation within Cakile maritima using the national herbaria collections and variation within new population samples. We support previous interpretations that Cakile maritima has been introduced on more than one occasion from morphologically distinct races, resulting in regional variation within Australia and high variability within populations in the south-east. Western Australian populations appear distinct and probably did not initiate those in the east; we consider that eastern populations are likely to be a mix of Cakile maritima subsp. maritima from the Mediterranean and Cakile maritima subsp. integrifolia from Atlantic Europe. Although introgression from Cakile edentula into Cakile maritima cannot be discounted from our results, it is not required to explain the levels of variation in the latter species observed in Australia. Cakile maritima continues to spread southwards in Tasmania and northwards in NSW; in Queenland, a recent occurrence has proliferated in Moreton Bay, spreading slowly to the north but not appreciably southwards

Imperfect inspection characterization for gamma process structural deterioration model

The deterioration of infrastructure facilities such as bridges has raised concerns over objective methodology to quantify the changes in their safety levels during the service life. In this paper the novel modeling of existing reinforced concrete structures likely future deterioration of strength is of interest. It is assumed that inspection outcomes are the source of data about the deterioration process and should provide help with the updating of the deterioration model with respect to the current structural condition. However, the inspection outcomes are associated with uncertainties that need to be taken into account for deterioration modeling. Sample reinforced concrete structure deterioration process is characterized as a time-dependent, non-negative and incremental process. In this paper we follow recent developments and the continuous gamma process has been adopted to represent the mathematical model of the deterioration process. In the current study two data sources were considered, the expert opinion, which is considered to reflect 'perfect inspection' and data obtained through scheduled inspections as 'imperfect inspection'. This paper reports on early development of the model to quantify the measurement error as inspection uncertainty and to establish continuous gamma process parameters for future deterioration prediction

Stochastic process deterioration modelling for adaptive inspections

In this paper we have considered an option to model deterioration process for infrastructure components using stochastic process representation as an alternative to random variable modelling that is prevalent approach when uncertainty is taken into account. In particular, we have identified that a Gamma process represents a very simple and effective method to establish consistent deterioration models for structures that are subject to inspection. As a result of such approach we see an opportunity to establish adaptive inspection regimes that would account much better for the structure specific deterioration path, site specific environment, in service inspection outcomes, inspection technique effectiveness, etc. An example is presented to demonstrate deterioration modelling and further work is identified

Linear wave dynamics explains observations attributed to dark-solitons in a polariton quantum fluid

We investigate the propagation and scattering of polaritons in a planar GaAs microcavity in the linear regime under resonant excitation. The propagation of the coherent polariton wave across an extended defect creates phase and intensity patterns with identical qualitative features previously attributed to dark and half-dark solitons of polaritons. We demonstrate that these features are observed for negligible nonlinearity (i.e., polariton-polariton interaction) and are, therefore, not sufficient to identify dark and half-dark solitons. A linear model based on the Maxwell equations is shown to reproduce the experimental observations.Comment: Article + Supplementary Information (tot. 18 pages

Statistical Mechanics of Lipid-Liquid Crystal Systems: From Fundamentals to Sensing Applications

Understanding the thermodynamics of small systems has a well-established history. The non-intuitive behavior of the intensive properties of small systems comprised of less than a few hundred particles has important implications in many areas of engineering and materials science. Nevertheless, many open questions about the thermophysical properties of systems not in the thermodynamic limit remain unanswered. In the first part of this work, we explore the consequences of the coupling of two small subsystems that together make up a larger isolated system through the use of statistical mechanics and molecular dynamics simulations of Lennard-Jones particles in two dimensions. The results from this study show that the average thermodynamic temperature and the average thermodynamic pressure of both subsystems can be different, with the relative difference being based on the number of particles making up the two subsystems. We also provide theoretical and simulation proof that the chemical potential of the two subsystems do not need to be the same if the temperature and pressure of the two subsystems are the same, as would be the case in the macroscopic limit. Ligand-receptor binding has traditionally been monitored by techniques that either requires a label to be attached to the analyte or complex optical methods to be detected. Phospholipid monolayers coupled with thermotropic liquid crystals as a responsive support can be used as a label-free biosensor. The hydrophobic acyl chains of the lipids contact the hydrophobic liquid crystal surface and the polar lipid head groups are presented to specific binding events involving proteins, enzymatic reactions, viruses, bacteria, etc. The mechanism by which lipid anchoring effects the liquid crystal surface remains to be elucidated. Therefore, a molecular study of the phospholipid/liquid crystal interface to determine the mechanisms by which binding events are transmitted from the analytes to the liquid crystal layer is crucial for the design of novel sensors. In the second part of this study, through a molecular model, we mimic the experimental systems by specifying interaction energies and their positional and angular dependencies. Our model allows us to fully characterize the organizations of phospholipids within the monolayer and also the orientations of liquid crystals in the bulk

CRISPR/Cas9-mediated deletion of a GA-repeat in human GPM6B leads to disruption of neural cell differentiation from NT2 cells

The human neuron-specific gene, GPM6B (Glycoprotein membrane 6B), is considered a key gene in neural cell functionality. This gene contains an exceptionally long and strictly monomorphic short tandem repeat (STR) of 9-repeats, (GA)9. STRs in regulatory regions, may impact on the expression of nearby genes. We used CRISPR-based tool to delete this GA-repeat in NT2 cells, and analyzed the consequence of this deletion on GPM6B expression. Subsequently, the edited cells were induced to differentiate into neural cells, using retinoic acid (RA) treatment. Deletion of the GA-repeat significantly decreased the expression of GPM6B at the RNA (p < 0.05) and protein (40%) levels. Compared to the control cells, the edited cells showed dramatic decrease of the astrocyte and neural cell markers, including GFAP (0.77-fold), TUBB3 (0.57-fold), and MAP2 (0.2-fold). Subsequent sorting of the edited cells showed an increased number of NES (p < 0.01), but a decreased number of GFAP (p < 0.001), TUBB3 (p < 0.05), and MAP2 (p < 0.01), compared to the control cells. In conclusion, CRISPR/Cas9-mediated deletion of a GA-repeat in human GPM6B, led to decreased expression of this gene, which in turn, disrupted differentiation of NT2 cells into neural cells.Publisher PDFPeer reviewe

EHD-Assisted Condensation of Refrigerant R-134a on Tube Bundles

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76561/1/AIAA-2002-3227-866.pd