Comparison of Motion Correction Methods Incorporating Motion Modelling for PET/CT Using a Single Breath Hold Attenuation Map

Introducing motion models into respiratory motion correction methods can lead to a reduction in blurring and artefacts. However, the pool of research where motion modelling methods are applied to combined positron emission tomography and computed tomography is relatively shallow. Previous work used non-attenuation corrected time-of-flight data to fit motion models, not only to motion correct the volumes themselves, but also to warp a single attenuation map to the positions of the initial gated data. This work seeks to extend previous work to offer a comparison of respiratory motion correction methods, not only with and without motion models, but also to compare pair-wise and group-wise registration techniques, on simulation data, in a low count scenario, where the attenuation map is from a pseudo-breath hold acquisition. To test the methods, 4-Dimensional Extended Cardiac Torso images are constructed, simulated and reconstructed without attenuation correction, then motion corrected using one of pair-wise, pair-wise with motion model, group-wise and group-wise with motion model registration. Next these motion corrected volumes are registered to the breath hold attenuation map. The positron emission tomography data are then reconstructed using deformed attenuation maps and motion corrected. Evaluation compares the results of these methods against non-motion corrected and motion free examples. Results indicate that the incorporation of motion models and group-wise registration, improves contrast and quantification

London region atlas of topsoil geochemistry

The London Region Atlas of Topsoil Geochemistry (LRA) is a further step towards understanding the chemical quality of soils in London, following a previous project called London Earth carried out by the British Geological Survey (BGS) (Johnson et al., 2010[1]). The main advantage of the LRA is that it includes soil geochemical data from the counties surrounding London; placing the city within the context of its rural hinterland, allowing assessments of the impact of urbanisation on soil quality. The London Region Atlas of Topsoil Geochemistry is a product derived from the BGS Geochemical Baseline Survey of the Environment (G-BASE[2]) project. The London Region Geochemical Dataset (LRD, n=8400), on which the atlas is based, includes TOPSOIL data from two complementary surveys: i) the urban London Earth (LOND) and ii) the rural South East England (SEEN). The LRA covers the Greater London Authority (GLA) and its outskirts in a rectangular area of 80x62 km. This extends from British National Grid coordinates Easting 490000–570000, and Northing 153000–215000. The urban LOND and the rural SEEN surveys contribute with 6801 and 1599 samples respectively to the LRD. The concentrations of 44 inorganic chemical elements (Al2O3, CaO, Fe2O3, K2O, MgO, MnO, Na2O, P2O5, SiO2, TiO2, Ag, As, Ba, Bi, Br, Cd, Ce, Co, Cr, Cs, Cu, Ga, Ge, Hf, I, La, Mo, Nb, Nd, Ni, Pb, Rb, Sb, Sc, Se, Sn, Sr, Th, U, V, W, Y, Zn and Zr), loss on ignition (LOI) and pH in topsoil are included in the LRA. For each element, a map showing the distribution in topsoil across the atlas area and a one-page sketch of descriptive statistics and graphs are presented. Statistics and graphs for whole dataset (LRD), London urban subset (LOND) and London surroundings rural subset (SEEN), as well as graphs of topsoil element concentrations over each simplified geology unit are shown. The LRD has been used already in a study aiming to detect geogenic (geological) signatures and controls on soil chemistry in the London region (Appleton et al., 2013[3]). It includes maps showing the distribution of Al, Si, La and I (and Th, Ca, Mn, As, Pb and Zr in supplementary material) and it is concluded that the spatial distribution of a range of elements is primarily controlled by the rocks from where soil derives, and that these geogenic patterns are still recognisable inside the urban centre. Other studies have been done that are based on data in the LRD, namely using the LOND subset or part of it. The main focus of these studies was the mercury content (Scheib et al., 2010[4]), the influence of land use on geochemistry (Knights and Scheib, 2011[5]; Lark and Scheib, 2013[6]); the bioaccessibility of pollutants such as As and Pb (Appleton et al., 2012[7]; Appleton et al., 2012[8]; Cave, 2012[9]; Appleton et al., 2013[10]; Cave et al., 2013[11]) and the lability of lead in soils (Mao et al., 2014[12]); the determination of normal background concentrations of contaminants in English soil (Ander et al., 2013[13]) and the contribution of geochemical and other environmental data to the future of the cities (Ludden et al., 2015[14]). The London Region Atlas of Topsoil Geochemistry formally presents detailed information for all chemical elements in the LRD. This information can be easily visualised and elements compared as its production and layout is standardised. Differences in topsoil element concentrations between the centre of the city and its outskirts can be assessed by observing the map and comparing statistics and graphs reported for the LOND and SEEN subsets respectively. This urban/rural contrast is particularly evident for elements such as Pb, Sb, Sn, Cu and Zn, for which mean concentrations in the urban environment are two to three times higher than those observed in the rural environment. This is a typical indicator suite of urban soil pollution reported in several other cities in the UK also (Fordyce et al., 2005[15])

The effects of laryngeal mask airway passage simulation training on the acquisition of undergraduate clinical skills: a randomised controlled trial

Background\ud Effective use of the laryngeal mask airway (LMA) requires learning proper insertion technique in normal patients undergoing routine surgical procedures. However, there is a move towards simulation training for learning practical clinical skills, such as LMA placement. The evidence linking different amounts of mannequin simulation training to the undergraduate clinical skill of LMA placement in real patients is limited. The purpose of this study was to compare the effectiveness in vivo of two LMA placement simulation courses of different durations. \ud \ud Methods\ud Medical students (n = 126) enrolled in a randomised controlled trial. Seventy-eight of these students completed the trial. The control group (n = 38) received brief mannequin training while the intervention group (n = 40) received additional more intensive mannequin training as part of which they repeated LMA insertion until they were proficient. The anaesthetists supervising LMA placements in real patients rated the participants' performance on assessment forms. Participants completed a self-assessment questionnaire. \ud \ud Results\ud Additional mannequin training was not associated with improved performance (37% of intervention participants received an overall placement rating of > 3/5 on their first patient compared to 48% of the control group, $X^2$ = 0.81, p = 0.37). The agreement between the participants and their instructors in terms of LMA placement success rates was poor to fair. Participants reported that mannequins were poor at mimicking reality. \ud \ud Conclusions\ud The results suggest that the value of extended mannequin simulation training in the case of LMA placement is limited. Educators considering simulation for the training of practical skills should reflect on the extent to which the in vitro simulation mimics the skill required and the degree of difficulty of the procedure. \ud \u

Modes of Foreign Entry under Asymmetric Information about Potential Technology Spillovers

This paper studies the effect of technology spillovers on the entry decision of a multinational enterprise into a foreign market. Two alternative entry modes for a foreign direct investment are considered: Greenfield investment versus acquisition. We find that with quantity competition a spillover makes acquisitions less attractive, while with price competition acquisitions become more attractive. Asymmetric information about potential spillovers always reduces the number of acquisitions independently of whether the host country or the entrant has private information. Interestingly, we find that asymmetric information always hurts the entrant, while it sometimes is in favor of the host country

ToxPi GUI: an interactive visualization tool for transparent integration of data from diverse sources of evidence

Motivation: Scientists and regulators are often faced with complex decisions, where use of scarce resources must be prioritized using collections of diverse information. The Toxicological Prioritization Index (ToxPi™) was developed to enable integration of multiple sources of evidence on exposure and/or safety, transformed into transparent visual rankings to facilitate decision making. The rankings and associated graphical profiles can be used to prioritize resources in various decision contexts, such as testing chemical toxicity or assessing similarity of predicted compound bioactivity profiles. The amount and types of information available to decision makers are increasing exponentially, while the complex decisions must rely on specialized domain knowledge across multiple criteria of varying importance. Thus, the ToxPi bridges a gap, combining rigorous aggregation of evidence with ease of communication to stakeholders

Decreased DGCR8 expression and miRNA dysregulation in individuals with 22q11.2 deletion syndrome

Deletion of the 1.5-3 Mb region of chromosome 22 at locus 11.2 gives rise to the chromosome 22q11.2 deletion syndrome (22q11DS), also known as DiGeorge and Velocardiofacial Syndromes. It is the most common micro-deletion disorder in humans and one of the most common multiple malformation syndromes. The syndrome is characterized by a broad phenotype, whose characterization has expanded considerably within the last decade and includes many associated findings such as craniofacial anomalies (40%), conotruncal defects of the heart (CHD; 70-80%), hypocalcemia (20-60%), and a range of neurocognitive anomalies with high risk of schizophrenia, all with a broad phenotypic variability. These phenotypic features are believed to be the result of a change in the copy number or dosage of the genes located in the deleted region. Despite this relatively clear genetic etiology, very little is known about which genes modulate phenotypic variations in humans or if they are due to combinatorial effects of reduced dosage of multiple genes acting in concert. Here, we report on decreased expression levels of genes within the deletion region of chromosome 22, including DGCR8, in peripheral leukocytes derived from individuals with 22q11DS compared to healthy controls. Furthermore, we found dysregulated miRNA expression in individuals with 22q11DS, including miR-150, miR-194 and miR-185. We postulate this to be related to DGCR8 haploinsufficiency as DGCR8 regulates miRNA biogenesis. Importantly we demonstrate that the level of some miRNAs correlates with brain measures, CHD and thyroid abnormalities, suggesting that the dysregulated miRNAs may contribute to these phenotypes and/or represent relevant blood biomarkers of the disease in individuals with 22q11DS

The ENIGMA Stroke Recovery Working Group: Big data neuroimaging to study brain–behavior relationships after stroke

The goal of the Enhancing Neuroimaging Genetics through Meta‐Analysis (ENIGMA) Stroke Recovery working group is to understand brain and behavior relationships using well‐powered meta‐ and mega‐analytic approaches. ENIGMA Stroke Recovery has data from over 2,100 stroke patients collected across 39 research studies and 10 countries around the world, comprising the largest multisite retrospective stroke data collaboration to date. This article outlines the efforts taken by the ENIGMA Stroke Recovery working group to develop neuroinformatics protocols and methods to manage multisite stroke brain magnetic resonance imaging, behavioral and demographics data. Specifically, the processes for scalable data intake and preprocessing, multisite data harmonization, and large‐scale stroke lesion analysis are described, and challenges unique to this type of big data collaboration in stroke research are discussed. Finally, future directions and limitations, as well as recommendations for improved data harmonization through prospective data collection and data management, are provided

Simple and efficient expression of Agaricus meleagris pyranose dehydrogenase in Pichia pastoris

Pyranose dehydrogenase (PDH) is a fungal flavin-dependent sugar oxidoreductase that is highly interesting for applications in organic synthesis or electrochemistry. The low expression levels of the filamentous fungus Agaricus meleagris as well as the demand for engineered PDH make heterologous expression necessary. Recently, Aspergillus species were described to efficiently secrete recombinant PDH. Here, we evaluate recombinant protein production with expression hosts more suitable for genetic engineering. Expression in Escherichia coli resulted in no soluble or active PDH. Heterologous expression in the methylotrophic yeast Pichia pastoris was investigated using two different signal sequences as well as a codon-optimized sequence. A 96-well plate activity screening for transformants of all constructs was established and the best expressing clone was used for large-scale production in 50-L scale, which gave a volumetric yield of 223 mg L−1 PDH or 1,330 U L−1 d−1 in space–time yield. Purification yielded 13.4 g of pure enzyme representing 95.8% of the initial activity. The hyperglycosylated recombinant enzyme had a 20% lower specific activity than the native enzyme; however, the kinetic properties were essentially identical. This study demonstrates the successful expression of PDH in the eukaryotic host organism P. pastoris paving the way for protein engineering. Additionally, the feasibility of large-scale production of the enzyme with this expression system together with a simplified purification scheme for easy high-yield purification is shown

Museum activities in dementia care: using visual analog scales to measure subjective wellbeing

Introduction: Previous research has shown that people with dementia and caregivers derive wellbeing-related benefits from viewing art in a group, and that facilitated museum object handling is effective in increasing subjective wellbeing for people with a range of health conditions. The present study quantitatively compared the impact of two museum-based activities and a social activity on the subjective wellbeing of people with dementia and their caregivers. Methods: A quasi-experimental crossover design was used. People with early to middle stage dementia and caregivers (N = 66) participated in museum object handling, a refreshment break and art-viewing in small groups. Visual analogue scales were used to rate subjective wellbeing pre and post each activity. Results: Mixed-design ANOVAs indicated wellbeing significantly increased during the session, irrespective of the order in which the activities were presented. Wellbeing significantly increased from object-handling and art-viewing for those with dementia and caregivers across pooled orders, but did not in the social activity of a refreshment break. An end-of-intervention questionnaire indicated that experiences of the session were positive. Conclusion: Results provide a rationale for considering museum activities as part of a broader psychosocial, relational approach to dementia care and support the use of easy to administer visual analogue scales as a quantitative outcome measure. Further partnership working is also supported between museums and healthcare professionals in the development of non-clinical, community-based programmes for this population