Patterns of Activity Expressed by Juvenile Horseshoe Crabs

Adult American horseshoe crabs, Limulus polyphemus, possess endogenous circadian and circatidal clocks controlling visual sensitivity and locomotion, respectively. The goal of this study was to determine the types of activity rhythms expressed by juvenile horseshoe crabs (n = 24) when exposed to a 14:10 light/dark cycle (LD) for 10 days, followed by 10 days of constant darkness (DD). Horseshoe crab activity was recorded with a digital time-lapse video system that used an infrared-sensitive camera so animals could be monitored at night. In LD, 15 animals expressed daily patterns of activity, 6 displayed a circatidal pattern, and the remaining 3 were arrhythmic. Of the 15 animals with daily patterns of locomotion, 7 had a significant preference (P \u3c 0.05) for diurnal activity and 3 for nocturnal activity; the remainder did not express a significant preference for day or night activity. In DD, 13 horseshoe crabs expressed circatidal rhythms and 8 maintained a pattern of about 24 h. Although these results suggest the presence of a circadian clock influencing circatidal patterns of locomotion, these apparent circadian rhythms may actually represent the expression of just one of the two bouts of activity driven by the putative circalunidian clocks that control their tidal rhythms. Overall, these results indicate that, like adults, juvenile horseshoe crabs express both daily and tidal patterns of activity and that at least one, and maybe both, of these patterns is driven by endogenous clocks

The reduced cost of providing a nationally recognised service for familial hypercholesterolaemia

OBJECTIVE: Familial hypercholesterolaemia (FH) affects 1 in 500 people in the UK population and is associated with premature morbidity and mortality from coronary heart disease. In 2008, National Institute for Health and Care Excellence (NICE) recommended genetic testing of potential FH index cases and cascade testing of their relatives. Commissioners have been slow to respond although there is strong evidence of cost and clinical effectiveness. Our study quantifies the recent reduced cost of providing a FH service using generic atorvastatin and compares NICE costing estimates with three suggested alternative models of care (a specialist-led service, a dual model service where general practitioners (GPs) can access specialist advice, and a GP-led service).METHODS: Revision of existing 3?year costing template provided by NICE for FH services, and prediction of costs for running a programme over 10?years. Costs were modelled for the first population-based FH service in England which covers Southampton, Hampshire, Isle of Wight and Portsmouth (SHIP). Population 1.95 million.RESULTS: With expiry of the Lipitor (Pfizer atorvastatin) patent the cost of providing a 10-year FH service in SHIP reduces by 42.5% (£4.88 million on patent vs £2.80 million off patent). Further cost reductions are possible as a result of the reduced cost of DNA testing, more management in general practice, and lower referral rates to specialists. For instance a dual-care model with GP management of patients supported by specialist advice when required, costs £1.89 million.CONCLUSIONS: The three alternative models of care are now <50% of the cost of the original estimates undertaken by NICE

GPS Rates of Vertical Bedrock Motion Suggest Late Holocene Ice-Sheet Readvance in a Critical Sector of East Antarctica

We investigate present-day bedrock vertical motion using new GPS timeseries from the Totten-Denman glacier region of East Antarctica (∼77-120°E) where models of glacial isostatic adjustment (GIA) disagree, glaciers are likely losing mass, and few data constraints on GIA exist. We show that varying surface mass balance loading (SMBL) is a dominant signal, contributing random-walk-like noise to GPS timeseries across Antarctica. In the study region, it induces site velocity biases of up to ∼+1 mm/yr over 2010-2020. After correcting for SMBL displacement and GPS common mode error, subsidence is evident at all sites aside from the Totten Glacier region where uplift is ∼1.5 mm/yr. Uplift near the Totten Glacier is consistent with late Holocene ice retreat while the widespread subsidence further west suggests possible late Holocene readvance of the region’s ice sheet, in broad agreement with limited glacial geological data and highlighting the need for sampling beneath the current ice sheet

A decade of horizontal deformation from great earthquakes

The 21st Century has seen the occurrence of 17 great earthquakes (Mw >8), including some of the largest earthquakes ever recorded. Numerical modeling of the earthquakes shows that nearly half of the Earth's surface has undergone horizontal coseismic defo

Representational precision in visual cortex reveals outcome encoding and reward modulation during action preparation

According to ideomotor theory, goal-directed action involves the active perceptual anticipation of actions and their associated effects. We used multivariate analysis of fMRI data to test if preparation of an action promotes precision in the perceptual representation of the action. In addition, we tested how reward magnitude modulates this effect. Finally, we examined how expectation and uncertainty impact neural precision in the motor cortex. In line with our predictions, preparation of a hand or face action increased the precision of neural activation patterns in the extrastriate body area (EBA) and fusiform face area (FFA), respectively. The size of this effect of anticipation predicted individuals\u27 efficiency at performing the prepared action. In addition, increasing reward magnitude increased the precision of perceptual representations in both EBA and FFA although this effect was limited to the group of participants that learned to associate face actions with high reward. Surprisingly, examination of representations in the hand motor cortex and face motor cortex yielded effects in the opposite direction. Our findings demonstrate that the precision of representations in visual and motor areas provides an important neural signature of the sensorimotor representations involved in goal-directed action

Laser Surface Preparation for Adhesive Bonding of Ti-6Al-4V

Adhesively bonded structures are potentially lighter in weight than mechanically fastened ones, but existing surface treatments are often considered unreliable. Two main problems in achieving reproducible and durable adhesive bonds are surface contamination and variability in standard surface preparation techniques. In this work three surface pretreatments were compared: laser etching with and without grit blasting and conventional Pasa-Jell treatment. Ti-6Al-4V surfaces were characterized by contact angle goniometry, optical microscopy, and X-ray photoelectron spectroscopy (XPS). Laser -etching was found to produce clean surfaces with precisely controlled surface topographies and PETI-5 lap shear strengths and durabilities were equivalent to those produced with Pasa-Jell

Automating rolling stock diagramming and platform allocation

Rolling stock allocation is the process of assigning timetable schedules to physical train units. This is primarily done by connecting together schedules at their terminal locations (known as schedule associations). Platforming allocation is the process of assigning those associations to particular platforms. A simple last-in, first-legal-out algorithm is used for rolling stock allocation that performs comparably to the traditional manual approach but only takes a few seconds as opposed to days or weeks in many manual cases. A simple stochastic hill-climbing approach is used for assigning associations to platforms to provide a conflict-free platform allocation within a few seconds. These two approaches are tested on real train planning problems with excellent results that would allow an expert to rapidly produce optimal or near optimal solutions. The time saving using these approaches can be used by the train planner to try out various options or have greater checking of robustness of the solutions created

Train timetable generation using genetic algorithms

The scheduling of railway trains has been a research problem for many years. Many of the choices required are not known a priori and require exploration of the problem to determine them. A modular Genetic system was designedmake the evaluation function and preparation of the timetable tractable. The Genetic system consists of a Genome, split into Chromosomes so the extra choices that become known throughout the evolution can be added to the Chromosomes. A weighted fitness function and a multiobjective non-dominated fitness function were tried, and then partial objective ranking was added. The system has tackled a mixture of problems has produced promising results

Lyplal1 is dispensable for normal fat deposition in mice.

Genome-wide association studies (GWAS) have detected association between variants in or near the Lysophospholipase-like 1 (LYPLAL1) locus and metabolic traits, including central obesity, fatty liver and waist-to-hip ratio. LYPLAL1 is also known to be upregulated in the adipose tissue of obese patients. However, the physiological role of LYPLAL1 is not understood. To investigate the function of Lyplal1 in vivo we investigated the phenotype of the Lyplal1tm1a(KOMP)Wtsi homozygous mouse. Body composition was unaltered in Lyplal1 knockout mice as assessed by dual-energy X-ray absorptiometry (DEXA) scanning, both on normal chow and on a high-fat diet. Adipose tissue distribution between visceral and subcutaneous fat depots was unaltered, with no change in adipocyte cell size. The response to both insulin and glucose dosing was normal in Lyplal1tm1a(KOMP)Wtsi homozygous mice, with normal fasting blood glucose concentrations. RNAseq analysis of liver, muscle and adipose tissue confirmed that Lyplal1 expression was ablated with minimal additional changes in gene expression. These results suggest that Lyplal1 is dispensable for normal mouse metabolic physiology and that despite having been maintained through evolution Lyplal1 is not an essential gene, suggesting possible functional redundancy. Further studies will be required to clarify its physiological role