Evidence for a schizophrenia vulnerability locus on chromosome 8p in the Irish Study of High-Density Schizophrenia Families

This study was an attempt to replicate evidence for a vulnerability locus for schizophrenia and associated disorders in the 8p22-21 region reported by Pulver and colleagues.

An efficient Cu(II)-bis(oxazoline)-based polymer immobilised ionic liquid phase catalyst for asymmetric carbon–carbon bond formation

The asymmetric Diels-Alder reaction between N-acryloyloxazolidinone and cyclopentadiene and the Mukaiyama-aldol reaction between methylpyruvate and 1-phenyl-1-trimethylsilyloxyethene have been catalysed by heterogeneous copper(II)-bis(oxazoline)-based polymer immobilised ionic liquid phase (PIILP) systems generated from a range of linear and cross linked ionic polymers. In both reactions selectivity and ee were strongly influenced by the choice of polymer. A comparison of the performance of a range of Cu(II)-bis(oxazoline)-PIILP catalyst systems against analogous supported ionic liquid phase (SILP) heterogeneous catalysts as well as their homogeneous counterparts has been undertaken and their relative merits evaluated.

Process-variation resilient and voltage-scalable dct architecture for robust low-power computing

In this paper, we present a novel discrete cosine transform (DCT) architecture that allows aggressive voltage scaling for low-power dissipation, even under process parameter variations with minimal overhead as opposed to existing techniques. Under a scaled supply voltage and/or variations in process parameters, any possible delay errors appear only from the long paths that are designed to be less contributive to output quality. The proposed architecture allows a graceful degradation in the peak SNR (PSNR) under aggressive voltage scaling as well as extreme process variations. Results show that even under large process variations (±3σ around mean threshold voltage) and aggressive supply voltage scaling (at 0.88 V, while the nominal voltage is 1.2 V for a 90-nm technology), there is a gradual degradation of image quality with considerable power savings (71% at PSNR of 23.4 dB) for the proposed architecture, when compared to existing implementations in a 90-nm process technology. © 2006 IEEE.

Coherence and discontinuity in the scaling of species' distribution patterns

The spatial distribution of a species can be characterized at many different spatial scales, from fine-scale measures of local population density to coarse-scale geographical-range structure. Previous studies have shown a degree of correlation in species' distribution patterns across narrow ranges of scales, making it possible to predict fine-scale properties from coarser-scale distributions. To test the limits of such extrapolation, we have compiled distributional information on 16 species of British plants, at scales ranging across six orders of magnitude in linear resolution (1 in to 100 km). As expected, the correlation between patterns at different spatial scales tends to degrade as the scales become more widely separated. There is, however, an abrupt breakdown in cross-scale correlations across intermediate (ca. 0.5 km) scales, suggesting that local and regional patterns are influenced by essentially non-overlapping sets of processes. The scaling discontinuity may also reflect characteristic scales of human land use in Britain, suggesting a novel method for analysing the 'footprint' of humanity on a landscape.

Lactobacilli possess inhibitory activity against dipeptidyl peptidase-4 (DPP-4)

Dipeptidyl peptidase 4 (DPP-4) enzymatically inactivates incretin hormones, and DPP-4 inhibitor drugs are clinically approved therapies for type 2 diabetes. The primary substrates of DPP-4 are produced in the intestinal lining and we therefore investigated whether lactobacilli colonizing the gut can inhibit this enzyme. Fifteen Lactobacillus strains (Lb 1-15) from human infant faecal samples were isolated, identified, extracted and screened for inhibitory activity against DPP-4. Activity was compared against Lactobacillus reference strains (Ref 1-7), a Gram positive control (Ctrl 1) and two Gram negative controls (Ctrl 2-3). A range of DPP-4 inhibitory activity was observed (10-32%; P<0.05-0.001). Strains of L. fabifermentans (25%), L. plantarum (12-24%) and L. fermentum (14%) had significant inhibitory activity. However, we also noted that E. coli (Ctrl 2) and S. Typhimurium (Ctrl 3) had the greatest inhibitory activity (30-32%). Contrastingly, some isolates (Lb 12-15) and reference cultures (Ref 1-4) instead of inhibiting DPP-4 actually enhanced it, perhaps indicating the presence of X-prolyl-dipeptidyl-amino-peptidase (PepX). This provides a future rationale for using probiotic bacteria or their components for management of type 2 diabetes via DPP-4 inhibition.

Calibrated integrated backscatter and myocardial fibrosis in patients undergoing cardiac surgery.

Objective - The reported association between calibrated integrated backscatter (cIB) and myocardial fibrosis is based on study of patients with dilated or hypertrophic cardiomyopathy and extensive (mean 15–34%) fibrosis. Its association with lesser degrees of fibrosis is unknown. We examined the relationship between cIB and myocardial fibrosis in patients with coronary artery disease.

Methods - Myocardial histology was examined in left ventricular epicardial biopsies from 40 patients (29 men and 11 women) undergoing coronary artery bypass graft surgery, who had preoperative echocardiography with cIB measurement.

Results - Total fibrosis (picrosirius red staining) varied from 0.7% to 4%, and in contrast to previous reports, cIB showed weak inverse associations with total fibrosis (r=−0.32, p=0.047) and interstitial fibrosis (r=−0.34, p=0.03). However, cIB was not significantly associated with other histological parameters, including immunostaining for collagens I and III, the advanced glycation end product (AGE) Nε-(carboxymethyl)lysine (CML) and the receptor for AGEs (RAGE). When biomarkers were examined, cIB was weakly associated with log plasma levels of amino-terminal pro-B-type natriuretic peptide (r=0.34, p=0.03), creatinine (r=0.33, p=0.04) and glomerular filtration rate (r=−0.33, p=0.04), and was more strongly associated with log plasma levels of soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) (r=0.44, p=0.01) and soluble RAGE (r=0.53, p=0.002).

Conclusions - Higher cIB was not a marker of increased myocardial fibrosis in patients with coronary artery disease, but was associated with higher plasma levels of sVEGFR-1 and soluble RAGE. The role of cIB as a non-invasive index of fibrosis in clinical studies of patients without extensive fibrosis is, therefore, questionable.