A modified hyperbolic tangent equation to determine equilibrium shape of headland bay beaches

When designing any artificial beach, it’s desirable to avoid (or minimise) future maintenance commitments by arranging the initial beach planshape so that it remains in equilibrium given the incident wave climate. Headlands bays, or embayments, where a sandy beach is held between two erosion resistant headlands, tend to evolve to a stable beach planshape with little movement of the beach contours over time. Several empirical bay shape equations have been derived to fit curves to the shoreline of headland bay beaches. One of the most widely adopted empirical equations is the parabolic bay shape equation, as it is the only equation that directly links the shoreline positions to the predominant wave direction and the point of diffraction. However, the main limitation with the application of the parabolic bay shape equation is locating the downcoast control point. As a result of research presented in this paper a new equation, based on the hyperbolic tangent shape equation was developed, which eliminates the requirement of placing the down coast control point and relies on defining a minimum beach width instead. This modified equation was incorporated into a new ArcGIS tool

Continuity and change in the institution of town and country planning: modelling the role of ideology

The institution of town and country planning rests upon ideas and concepts which will always be contested. Such concepts include ‘liberty’, ‘community’, ‘society’ and ‘the state’. It is a function of political ideology to seek to fix the meanings of contested concepts and thus exert control over political reality. By analysing the particular conceptual structure of the ideologies which seek to influence planning from positions of political power, the analyst can show how these ideologies are related to shifts in the conceptual and institutional structure of planning. The paper illustrates this analytical method in the context of the transition from the ideology of New Labour to the ideology of the Conservative-led Coalition government in England after 2010

CT angiography compared to invasive angiography for stable coronary disease as predictors of Major Adverse Cardiovascular Events- a systematic review and meta-analysis

Background: Computational tomography coronary angiography (CTCA) is increasingly the diagnostic test of choice for investigating patients with stable anginal symptoms. Objectives: We sought to conduct a systematic review and meta-analysis comparing CTCA with invasive coronary angiography (ICA) with regards to major adverse cardiovascular events (MACE), procedural complications and rates of revascularisation. Methods: We conducted a systematic review and meta-analysis in line with the PRISMA statement. A literature search was conducted using PubMed, MEDLINE Ovid and Embase, with three studies included in meta-analysis. Statistical analysis was undertaken using Review Manager 5.3 for MacOS software and outcomes expressed as odds ratio, with 95% confidence intervals and sensitivity analysis was conducted. Results: A total of 5662 patients were included in this study level meta-analysis. There was no difference in MACE between CT and angiography [2.97% v 3.45%, fixed-effect model, OR: 0.84 (0.62–1.14), p = 0.26, I2 0%] and no difference found in rates of myocardial infarction, death or stroke. CTCA was associated with a reduced rate of revascularisation [12.6% v 18.3%, fixed-effects model, OR: 0.64 (0.55–0.75), p<0.00001, I2 =0%]. However, CTCA was not associated with a significantly lower complication rate [0.5% v 1.72%, random effects model, OR: 0.52 (0.06–4.38), p = 0.55, I2 52%]. Conclusion: CTCA is a safe strategy for investigating patients with stable angina with no associated increase in MACE but a reduction in revascularisation rates

Replication of bromodeoxyuridylate-substituted mitochondrial DNA in yeast

The DNA of several strains of Saccharomyces cerevisiae was labeled by growing the culture in medium supplemented with thymidylate and bromodeoxyuridylate. It was thus possible to follow the course of mitochondrial DNA replication in density shift experiments by determining the buoyant density distribution of unreplicated and replicated DNAs in analytical CsCl gradients. DNA replication was followed for three generations after transfer of cultures from light medium to heavy medium and heavy medium to light medium. Under both conditions, the density shifts observed for mitochondrial DNA were those expected for semiconservative, nondispersive replication. This was further confirmed by analysis of the buoyant density of alkali-denatured hybrid mitochondrial DNA. With this method, no significant recombination between replicated and unreplicated DNA was detected after three generations of growth.</jats:p

Carbon catabolite repression of maltase synthesis in Saccharomyces carlsbergensis

Carbon catabolite repression of maltase gene expression is brought about by the addition of glucose, resulting in a drastic inhibition of the induction of maltase. When added to induced cells, glucose leads to the inhibition of maltase synthesis within 30 min, which can be accounted for by the disappearance of hybridizable maltase RNA sequences. The loss of maltase-specific RNA due to catabolite repression can be traced to the combined effects of a 15-fold decrease in the rate of transcription of the maltase structural gene 15 to 20 min after the addition of glucose and a change in the half-life of maltase mRNA. However, the stability of maltase, once induced, is not affected by the addition of glucose.</jats:p

Regulation of maltase synthesis in Saccharomyces carlsbergensis

The induction of maltase (EC 3.2.1.20) by its inducer maltose in a strain of the yeast Saccharomyces carlsbergensis carrying a functional MAL locus is regulated at the level of transcription. Preceding the synthesis of increased levels of maltase is the de novo synthesis of maltase-specific RNA sequences. This was detected by determining the level of maltase mRNA by DNA-RNA hybridizations by using a maltase structural gene DNA sequence probe and by assaying functional maltase mRNA by in vitro RNA-directed synthesis of immunologically reactive maltase. Once maltase has accumulated, late in induction, further synthesis of the enzyme is inhibited, as reflected by reduced levels of the mRNA that encodes maltase.</jats:p