Implementing RSVP as an Image Browser

Rapid Serial Visual Presentation (RSVP) is an effective tool for information navigation. We applied RSVP to the increasingly important task of image browsing. In total nine RSVP interfaces were developed, implementing three RSVP modes and three control sets. An evaluation was carried out to investigate the effect of RSVP mode and control set on image retrieval time. S

Three Drosophila Hox Complex microRNAs Do Not Have Major Effects on Expression of Evolutionarily Conserved Hox Gene Targets during Embryogenesis

The discovery of microRNAs has resulted in a major expansion of the number of molecules known to be involved in gene regulation. Elucidating the functions of animal microRNAs has posed a significant challenge as their target interactions with messenger RNAs do not adhere to simple rules. Of the thousands of known animal microRNAs, relatively few microRNA:messenger RNA regulatory interactions have been biologically validated in an normal organismal context. Here we present evidence that three microRNAs from the Hox complex in Drosophila (miR-10-5p, miR-10-3p, miR-iab-4-5p) do not have significant effects during embryogenesis on the expression of Hox genes that contain high confidence microRNAs target sites in the 3′ untranslated regions of their messenger RNAs. This is significant, in that it suggests that many predicted microRNA-target interactions may not be biologically relevant, or that the outcomes of these interactions may be so subtle that mutants may only show phenotypes in specific contexts, such as in environmental stress conditions, or in combinations with other microRNA mutations

The added value of system robustness analysis for flood risk management

Decision makers in fluvial flood risk management increasingly acknowledge that they have to prepare for extreme events. Flood risk is the most common basis on which to compare flood risk-reducing strategies. To take uncertainties into account the criteria of robustness and flexibility are advocated as well. This paper discusses the added value of robustness as additional decision criterion compared to single-value flood risk only. We do so by quantifying flood risk and system robustness for alternative system configurations of the Ijssel River valley in the Netherlands. We found that robustness analysis has added value in three respects: (1) it does not require assumptions on current and future flood probabilities, since flood consequences are shown as a function of discharge, (2) it shows the sensitivity of the system to varying discharges and (3) it supports a discussion on the acceptability of flood damage. We conclude that robustness analysis is a valuable addition to flood risk analysis in support of long-term decision-making on flood risk managemen

Preliminary transcriptome analysis and Homeobox gene isonlation for Tomocerus minor (Entomobryomorpha: Tomoceridae)

Collembola, or “springtails,” are small, edaphic arthropods classified as Entognatha; a group traditionally included as part of Hexapoda and sister-group to the true insects. However, some genetic studies suggest that they may instead have derived from a separate crustacean lineage rather than from a proto-Insecta lineage. The unique abdominal structures that develop on the collembolan ventral abdomen appear to be appendicular in origin – atypical to the canonical, appendage-less insect abdomen ground plan. I developed culture and embryo fixation protocols for; and sequenced and analyzed a multi-stage embryo transcriptome for Tomocerus minor (Collembola: Entomobryomorpha). This analysis annotated 14,417 distinct genes, identified all eight Hox genes, and several other genes that play a role in appendage and abdominal development during embryogenesis. I designed primers for eight target genes (Antp, Ubx, abdA, AbdB, Cad, en, inv, Dll) and successfully amplified portions of these genes, producing PCR products at predicted lengths

Influence of nutrition on feline calcium oxalate urolithiasis with emphasis on endogenous oxalate synthesis

The prevalence of calcium oxalate (CaOx) uroliths detected in cats with lower urinary tract disease has shown a sharp increase over the last decades with a concomitant reciprocal decrease in the occurrence of struvite (magnesium ammonium phosphate) uroliths. CaOx stone-preventative diets are available nowadays, but seem to be marginally effective, as CaOx urolith recurrence occurs in patients fed these diets. In order to improve the preventative measures against CaOx urolithiasis, it is important to understand its aetiopathogenesis. The main research focus in CaOx formation in cats has been on the role of Ca, whereas little research effort has been directed towards the role and origin of urinary oxalates. As in man, the exogenous origin of urinary oxalates in cats is thought to be of minor importance, although the precise contribution of dietary oxalates remains unclear. The generally accepted dietary risk factors for CaOx urolithiasis in cats are discussed and a model for the biosynthetic pathways of oxalate in feline liver is provided. Alanine:glyoxylate aminotransferase 1 (AGT1) in endogenous oxalate metabolism is a liver-specific enzyme targeted in the mitochondria in cats, and allows for efficient conversion of glyoxylate to glycine when fed a carnivorous diet. The low peroxisomal activity of AGT1 in cat liver is compatible with the view that felids utilised a low-carbohydrate diet throughout evolution. Future research should focus on understanding de novo biosynthesis of oxalate in cats and their adaptation(s) in oxalate metabolism, and on dietary oxalate intake and absorption by cats

Mathematical diffraction of aperiodic structures

Kinematic diffraction is well suited for a mathematical approach via measures, which has substantially been developed since the discovery of quasicrystals. The need for further insight emerged from the question of which distributions of matter, beyond perfect crystals, lead to pure point diffraction, hence to sharp Bragg peaks only. More recently, it has become apparent that one also has to study continuous diffraction in more detail, with a careful analysis of the different types of diffuse scattering involved. In this review, we summarise some key results, with particular emphasis on non-periodic structures. We choose an exposition on the basis of characteristic examples, while we refer to the existing literature for proofs and further details

Analysis of ammonium uptake; a sigma 54 regulated function in rhizobium meliloti

Ammonium transport was examined in the symbiotic nitrogenfixing acterium Rhizobium meliloti. This was done by assaying for the uptake of a radio-labelled analogue of ammonium, 14C-methylamine. The activity was shown to vary depending on the nitrogen source and its concentration m the growth medium, and to be inducible. The effect of various compounds on the actual assay itself was also assessed. Ammonium, methylamme and glutamine were found to inhibit uptake, as did sodium azide, indicating that it was an energy-requiring process. Several mutants in nitrogen assimilation were assayed for uptake, and this showed the activity to be dependent on the sigma factor a54 and its associated activator protein NtrC, but not on the three genes for glutamine synthetase found m R . meliloti. Genes transcribed by a54 show a highly conserved promoter sequence m the -24/-12 region. A primer designed to this sequence allowed use of the PCR technique to amplify fragments containing this sequence from a gene bank of R . meliloti. These PCR products were then cloned, and eight transformants with different sized inserts selected for sequencing. Analysis of the sequence data showed one to contain the start of the m f H gene, known to be (independent, and thereby validating this method for the isolation of a group of promoter-specific genes

Application of molecular techniques for the assessment of microorganism diversity on cultural heritage objects

As a result of their unpredictable ability to adapt to varying environmental conditions, microorganisms inhabit different types of biological niches on Earth. Owing to the key role of microorganisms in many biogeochemical processes, trends in modern microbiology emphasize the need to know and understand the structure and function of complex microbial communities. This is particularly important if the strategy relates to microbial communities that cause biodeterioration of materials that constitute our cultural heritage. Until recently, the detection and identification of microorganisms inhabiting objects of cultural value was based only on cultivation-dependent methods. In spite of many advantages, these methods provide limited information because they identify only viable organisms capable of growth under standard laboratory conditions. However, in order to carry out proper conservation and renovation, it is necessary to know the complete composition of microbial communities and their activity. This paper presents and characterizes modern techniques such as genetic fingerprinting and clone library construction for the assessment of microbial diversity based on molecular biology. Molecular methods represent a favourable alternative to culture dependent methods and make it possible to assess the biodiversity of microorganisms inhabiting technical materials and cultural heritage objects