Comparison of cardiovascular risk between patients with type 2 diabetes and those who had had a myocardial infarction: cross sectional and cohort studies [Erratum published Volume 324, Issue 7350, 8 June 2002, Page 1357)

Objective: To compare risks of cardiovascular outcomes between patients with type 2 diabetes and patients with established coronary heart disease. Design: Cross sectional study and cohort study using routinely collected datasets. Setting: Tayside, Scotland (population 400 000) during 1988-­95. Subjects: In the cross sectional study, among patients aged 45­64, 1155 with type 2 diabetes were compared with 1347 who had had a myocardial infarction in the preceding 8 years. In the cohort study 3477 patients of all ages with newly diagnosed type 2 diabetes were compared with 7414 patients who had just had a myocardial infarction. Main outcome measures: Risk ratios for death from all causes, cardiovascular death, and hospital admission for myocardial infarction were calculated by Cox proportional hazards analysis and adjusted for age and sex. Results: In the cross sectional study the adjusted risk ratio for death from all causes was 2.27 (95% confidence interval 1.82 to 2.83) for patients who had had myocardial infarction compared with those with diabetes, and the risk ratio for hospital admission for myocardial infarction was 1.33 (1.14 to 1.55). In the cohort study, patients who had just had a myocardial infarction had a higher risk of death from all causes (adjusted risk ratio 1.35 (1.25 to 1.44)), cardiovascular death (2.93 (2.54 to 3.41)), and hospital admission for myocardial infarction (3.10 (2.57 to 3.73)). Conclusions: Patients with type 2 diabetes were at lower risk of cardiovascular outcomes than patients with established coronary heart disease

Two-dimensional colloidal fluids exhibiting pattern formation

Fluids with competing short range attraction and long range repulsive interactions between the particles can exhibit a variety of microphase separated structures. We develop a lattice-gas (generalised Ising) model and analyse the phase diagram using Monte Carlo computer simulations and also with density functional theory (DFT). The DFT predictions for the structures formed are in good agreement with the results from the simulations, which occur in the portion of the phase diagram where the theory predicts the uniform fluid to be linearly unstable. However, the mean-field DFT does not correctly describe the transitions between the different morphologies, which the simulations show to be analogous to micelle formation. We determine how the heat capacity varies as the model parameters are changed. There are peaks in the heat capacity at state points where the morphology changes occur. We also map the lattice model onto a continuum DFT that facilitates a simplification of the stability analysis of the uniform fluid.Comment: 13 pages, 15 figure

On the interplay between sedimentation and phase separation phenomena in two-dimensional colloidal fluids

Colloidal particles that are confined to an interface effectively form a two-dimensional fluid. We examine the dynamics of such colloids when they are subject to a constant external force, which drives them in a particular direction over the surface. Such a situation occurs, for example, for colloidal particles that have settled to the bottom of their container, when the container is tilted at an angle, so that they `sediment' to the lower edge of the surface. We focus in particular on the case when there are attractive forces between the colloids which causes them to phase separate into regions of high density and low density and we study the influence of this phase separation on the sedimentation process. We model the colloids as Brownian particles and use both Brownian dynamics computer simulations and dynamical density functional theory (DDFT) to obtain the time evolution of the ensemble average one-body density profiles of the colloids. We consider situations where the external potential varies only in one direction so that the ensemble average density profiles vary only in this direction. We solve the DDFT in one-dimension, by assuming that the density profile only varies in one direction. However, we also solve the DDFT in two-dimensions, allowing the fluid density profile to vary in both the $x$- and $y$-directions. We find that in certain situations the two-dimensional DDFT is clearly superior to its one-dimensional counterpart when compared with the simulations and we discuss this issue.Comment: 17 pages, 10 figures, submitted to Molecular Physic

Elastic constants of 3-, 4- and 6-connected chiral and anti-chiral honeycombs subject to uniaxial in-plane loading

Finite Element models are developed for the in-plane linear elastic constants of a family of honeycombs comprising arrays of cylinders connected by ligaments. Honeycombs having cylinders with 3, 4 and 6 ligaments attached to them are considered, with two possible configurations explored for each of the 3- (trichiral and anti-trichiral) and 4- (tetrachiral and anti-tetrachiral) connected systems. Honeycombs for each configuration have been manufactured using rapid prototyping and subsequently characterised for mechanical properties through in-plane uniaxial loading to verify the models. An interesting consequence of the family of 'chiral' honeycombs presented here is the ability to produce negative Poisson's ratio (auxetic) response. The deformation mechanisms responsible for auxetic functionality in such honeycombs are discussed

Grazing winter wheat relieves plant water stress and transiently enhances photosynthesis

In order to model the impact of grazing on wheat growth, we measured photosynthesis in the field. Grazing may affect photosynthesis as a consequence of changes to leaf water status, nitrogen content per unit leaf area (Na) or photosynthetic enzyme activity. While light-saturated CO2 assimilation rates (Asat) of field-grown wheat were unchanged during grazing, Asat transiently increased by 33-68% compared to ungrazed leaves over a two-four week period after grazing ended. Grazing reduced leaf mass per unit area, increased stomatal conductance and increased intercellular CO2 concentrations (Ci) by 36-38%, 88-169% and 17-20%, respectively. Grazing did not alter Na. Using a photosynthesis model, we demonstrated that the increase in Asat after grazing required an increase in Rubisco activity of up to 53%, whereas the increase in Ci could only increase Asat by up to 13%. Increased Rubisco activity was associated with a partial alleviation of leaf water stress. We observed a 68% increase in leaf water potential of grazed plants which could be attributed to reduced leaf area index and canopy evaporative demand, as well as increased rainfall infiltration into soil. The grazing of rain-fed grain cereals may be tailored to relieve plant water stress and enhance leaf photosynthesis

Basal Cell Carcinomas in Gorlin Syndrome: A Review of 202 Patients

Gorlin syndrome (Naevoid Basal Cell Carcinoma Syndrome) is a rare autosomal dominant syndrome caused by mutations in the PTCH gene with a birth incidence of approximately 1 in 19,000. Patients develop multiple basal cell carcinomas of the skin frequently in early life and also have a predisposition to additional malignancies such as medulloblastoma. Gorlin Syndrome patients also have developmental defects such as bifid ribs and other complications such as jaw keratocysts. We studied the incidence and frequency of basal cell carcinomas in 202 Gorlin syndrome patients from 62 families and compared this to their gender and mutation type. Our data suggests that the incidence of basal cell carcinomas is equal between males and females and the mutation type cannot be used to predict disease burden

Viruses inhibit CO2 fixation in the most abundant phototrophs on Earth

R.J.P. was the recipient of a NERC studentship and Warwick University IAS fellowship. This work was supported in part by NERC grant NE/J02273X/1 and Leverhulme Trust grant RPG-2014-354 to A.D.M., D.J.E., and D.J.S.Summary. Marine picocyanobacteria of the genera Prochlorococcus and Synechococcus are the most numerous photosynthetic organisms on our planet [1, 2]. With a global population size of 3.6 × 1027 [3], they are responsible for approximately 10% of global primary production [3, 4]. Viruses that infect Prochlorococcus and Synechococcus (cyanophages) can be readily isolated from ocean waters [5–7] and frequently outnumber their cyanobacterial hosts [8]. Ultimately, cyanophage-induced lysis of infected cells results in the release of fixed carbon into the dissolved organic matter pool [9]. What is less well known is the functioning of photosynthesis during the relatively long latent periods of many cyanophages [10, 11]. Remarkably, the genomes of many cyanophage isolates contain genes involved in photosynthetic electron transport (PET) [12–18] as well as central carbon metabolism [14, 15, 19, 20], suggesting that cyanophages may play an active role in photosynthesis. However, cyanophage-encoded gene products are hypothesized to maintain or even supplement PET for energy generation while sacrificing wasteful CO2 fixation during infection [17, 18, 20]. Yet this paradigm has not been rigorously tested. Here, we measured the ability of viral-infected Synechococcus cells to fix CO2 as well as maintain PET. We compared two cyanophage isolates that share different complements of PET and central carbon metabolism genes. We demonstrate cyanophage-dependent inhibition of CO2 fixation early in the infection cycle. In contrast, PET is maintained throughout infection. Our data suggest a generalized strategy among marine cyanophages to redirect photosynthesis to support phage development, which has important implications for estimates of global primary production.Publisher PDFPeer reviewe