Nanowire spintronics for storage class memories and logic

Patterned magnetic nanowires are extremely well suited for data storage and logic devices. They offer non-volatile storage, fast switching times, efficient operation and a bistable magnetic configuration that are convenient for representing digital information. Key to this is the high level of control that is possible over the position and behaviour of domain walls (DWs) in magnetic nanowires. Magnetic random access memory based on the propagation of DWs in nanowires has been released commercially, while more dynamic shift register memory and logic circuits have been demonstrated. Here, we discuss the present standing of this technology as well as reviewing some of the basic DW effects that have been observed and the underlying physics of DW motion. We also discuss the future direction of magnetic nanowire technology to look at possible developments, hurdles to overcome and what nanowire devices may appear in the future, both in classical information technology and beyond into quantum computation and biology.

Specific attentional impairments and complex visual hallucinations in eye disease

OBJECTIVE

To test the prediction by the Perception and Attention Deficit (PAD) model of complex visual hallucinations that cognitive impairment, specifically in visual attention, is a key risk factor for complex hallucinations in eye disease.

METHODS

Two studies of elderly patients with acquired eye disease investigated the relationship between complex visual hallucinations (CVH) and impairments in general cognition and verbal attention (Study 1) and between CVH, selective visual attention and visual object perception (Study 2). The North East Visual Hallucinations Inventory was used to classify CVH.

RESULTS

In Study 1, there was no relationship between CVH (n=10/39) and performance on cognitive screening or verbal attention tasks. In Study 2, participants with CVH (n=11/31) showed poorer performance on a modified Stroop task (p<0.05), a novel imagery-based attentional task (p<0.05) and picture (p<0.05) but not silhouette naming (p=0.13) tasks. Performance on these tasks correctly classified 83% of the participants as hallucinators or non-hallucinators.

CONCLUSIONS

The results suggest that, consistent with the PAD model, complex visual hallucinations in people with acquired eye disease are associated with visual attention impairment.

Protection Against Nephropathy in Diabetes with Atorvastatin (PANDA): a randomized double-blind placebo-controlled trial of high- vs. low-dose atorvastatin(1)

AIMS

To compare the renal effects of low- vs. high-dose atorvastatin in patients with Type 2 diabetes mellitus and optimally managed early renal disease.

METHODS

We compared the 2-year progression of nephropathy in a double-blind randomized controlled trial of atorvastatin 80 mg/day (n = 60) vs. 10 mg/day (n = 59) in patients with Type 2 diabetes with microalbuminuria or proteinuria [mean (sd): age 64 years (10 years); HbA(1c) 7.7% (1.3%), 61 mmol/mol (10 mmol/mol); blood pressure 131/73 mmHg; renin-angiotensin system blocker use > 80%; dual blockade > 67%] recruited from diabetes clinics in Greater Manchester.

RESULTS

Over (mean) 2.1 years of follow-up, the Modification of Diet in Renal Disease estimated glomerular filtration rate declined by 3 ml min(-1) 1.73 m(-2) in the combined group. The mean (95% CI) between-group difference during follow-up was not significant [2.2 ml min(-1) 1.73 m(-2) (-1.1 to 5.4 ml min(-1) 1.73: m(-2) ), P = 0.20] after adjusting for baseline differences in renal function; positive difference favours 80 mg dose. Similarly, there was no significant difference in creatinine clearance by Cockcroft and Gault [2.5 ml/min (-2.4 to 7.3 ml/min), P = 0.32]; serum creatinine/24-h urine collections [4.0 ml/min (-4.8 to 12.7 ml/min), P = 0.38]; cystatin C (P = 0.69); or 24-h urine protein or albumin excretion (P = 0.92; P = 0.93). We recorded no significant between-group differences in deaths or adverse events.

CONCLUSIONS

In patients with Type 2 diabetes with early renal disease, we found no statistical difference in renal function between those taking high- or low-dose atorvastatin over 2 years. We cannot exclude a beneficial effect of < 1.6 ml min(-1) 1.73 m(-2) year(-1) on Modification of Diet in Renal Disease estimated glomerular filtration rate, or if blood pressure management or if renin-angiotensin system blocker use had not been optimized.

Does Tribolium brevicornis cuticular chemistry deter cannibalism and predation of pupae?

The cuticular hydrocarbons of insects are species-specific and often function as semiochemicals. The activity of Tribolium brevicornis cuticular hydrocarbons as feeding deterrents that ostensibly function to prevent pupal cannibalism and predation was evaluated. The cuticular hydrocarbons of T. brevicornis pupae were characterized and flour disk bioassays conducted with individual and combined extract components incorporated into artificial diets on which Tribolium adults fed for six days. Feeding by T. brevicornis and T. castaneum on flour disks containing cuticular extracts of T. brevicornis pupae resulted in reduced consumption and weight loss relative to feeding on control flour disks. In both cases, feeding deterrence indices exceeded 80% suggesting that T. brevicornis cuticular hydrocarbons could function to deter cannibalism and predation of pupae by larvae and adult beetles. Sixteen different cuticular hydrocarbons were identified in T. brevicornis pupal extracts. Eight of the commercially available linear alkanes were tested individually in feeding trials with eight Tribolium species. One compound (C28) significantly reduced the amount of food consumed by three species compared to control disks, whereas the compounds C25, C26, and C27 elicited increased feeding in some species. Four other compounds had no effect on consumption for any species. When four hydrocarbon mixtures were tested for synergistic deterrence on T. brevicornis and T. castaneum, none significantly influenced consumption. Our results indicate that the cuticular chemistry of T. brevicornis pupae could serve to deter predation by conspecific and congeneric beetles.

Ploy and counterploy in predator-prey interactions: Orb-weaving spiders versus bombardier beetles

Bombardier beetles (Brachinus spp.) offered to orb-weaving spiders are either captured or lost, depending on the attack strategy of the spider. Nephila clavipes grasps a beetle directly and attempts to bite it outright, but is repelled by the beetle's defensive spray. As the spider recovers from the spray, the beetle makes its escape from the web. Argiope first imprisons the beetle by wrapping it delicately in silk, without causing it to spray. When the spider then proceeds to bite, the wrapping protects it against the full effects of the spray. The wrapping strategy may be generally effective against chemically protected insects, and it is suggested that this may be one of its principal adaptive justifications.

Erectile dysfunction and coronary artery disease prediction: evidence-based guidance and consensus

* A significant proportion of men with erectile dysfunction (ED) exhibit early signs of coronary artery disease (CAD), and this group may develop more severe CAD than men without ED (Level 1, Grade A). * The time interval among the onset of ED symptoms and the occurrence of CAD symptoms and cardiovascular events is estimated at 2-3 years and 3-5 years respectively; this interval allows for risk factor reduction (Level 2, Grade B). * ED is associated with increased all-cause mortality primarily due to increased cardiovascular mortality (Level 1, Grade A). * All men with ED should undergo a thorough medical assessment, including testosterone, fasting lipids, fasting glucose and blood pressure measurement. Following assessment, patients should be stratified according to the risk of future cardiovascular events. Those at high risk of cardiovascular disease should be evaluated by stress testing with selective use of computed tomography (CT) or coronary angiography (Level 1, Grade A). * Improvement in cardiovascular risk factors such as weight loss and increased physical activity has been reported to improve erectile function (Level 1, Grade A). * In men with ED, hypertension, diabetes and hyperlipidaemia should be treated aggressively, bearing in mind the potential side effects (Level 1, Grade A). * Management of ED is secondary to stabilising cardiovascular function, and controlling cardiovascular symptoms and exercise tolerance should be established prior to initiation of ED therapy (Level 1, Grade A). * Clinical evidence supports the use of phosphodiesterase 5 (PDE5) inhibitors as first-line therapy in men with CAD and comorbid ED and those with diabetes and ED (Level 1, Grade A). * Total testosterone and selectively free testosterone levels should be measured in all men with ED in accordance with contemporary guidelines and particularly in those who fail to respond to PDE5 inhibitors or have a chronic illness associated with low testosterone (Level 1, Grade A). * Testosterone replacement therapy may lead to symptomatic improvement (improved wellbeing) and enhance the effectiveness of PDE5 inhibitors (Level 1, Grade A). * Review of cardiovascular status and response to ED therapy should be performed at regular intervals (Level 1, Grade A).