Locked oscillator phase modulator, appendix d final report

Design parameters for linear phase modulation of locked oscillato

Evaluation of interventions for informed consent for randomised controlled trials (ELICIT) : protocol for a systematic review of the literature and identification of a core outcome set using a Delphi survey

Acknowledgements This work was supported by personal fellowship award (to KG) from the Medical Research Council’s Strategic Skills Methodology programme. The Health Services Research Unit is supported by a core grant from the Chief Scientist Office of the Scottish Government Health and Social Care Directorates. PW is funded by a UK Medical Research Council Hub for Trials Methodology Research Network grant G0800792. The views and opinions expressed therein are those of the authors and do not necessarily reflect those of the Chief Scientist Office, MRC or the Department of Health.Peer reviewedPublisher PD

Exact nonadiabatic part of the Kohn-Sham potential and its fluidic approximation

We present a simple geometrical "fluidic" approximation to the nonadiabatic part of the Kohn-Sham potential, vKS, of time-dependent density-functional theory (DFT). This part of vKS is often crucial, but most practical functionals utilize an adiabatic approach based on ground-state DFT, limiting their accuracy in many situations. For a variety of model systems, we calculate the exact time-dependent electron density and find that the fluidic approximation corrects a large part of the error arising from the "exact adiabatic" approach, even when the system is evolving far from adiabatically

The spur planetary gear torsional stiffness and its crack sensitivity under quasi-static conditions

The sun-planet and ring-planet tooth mesh stiffness variations and the resulting transmission errors are the main internal vibration generation mechanisms for planetary gear systems. This paper presents the results of torsional stiffness analysis of involute spur planetary gear systems in mesh using finite element methods. A planetary gear model with three planet gears and fixed ring gear and its subsystem models have been developed to study the subsystem and overall torsional stiffnesses. Based on the analysis of torsional mesh stiffness, predictive models for single branch sun-planet-ring and overall planetary gear torsional stiffnesses have been proposed. A crack coefficient was introduced to the sun-planet and ring-planet meshes to predict the effect and sensitivity of changes to the overall torsional mesh stiffness. The resulting mesh stiffness crack sensitivity of the overall gear system was analysed under quasi-static conditions. It was found that the carrier arm stiffness has great influence on the crack sensitivity while the overall stiffness was most sensitive to the crack on the sun-planet mesh

An Estimation of Daily Intake of Potentially Toxic Elements from Urban Dust of Abakaliki, Nigeria

This study examined the total concentration of eight potentially toxic elements (PTEs) in urban dust of Abakaliki and also calculated the daily intake (DI) of these PTEs. Fifteen samples were investigated and the result revealed that the range of mean total PTE concentrations was found in this order: 3.59 – 15.3 mg/kg (As); 66.8 -172 mg/kg (Cd); 0.288 – 1.36 mg/kg (Cr); 25.4 – 86.6 mg/kg (Cu); 55.5 – 1815 mg/kg (Pb); 397 – 1389 mg/kg (Mn); 22.3 – 52.7 mg/kg (Ni) and 73.3 – 434 mg/kg (Zn). For each element the highest concentration (representing the worst-case scenario was used to calculate the daily intake and it was observed that only Pb with a DI of 4.88 μg kgbw -1 day-1 exceeded Pb recommended tolerable daily intake (TDI) of 3.6 μg kgbw-1 day-1. Based on a soil and dust ingestion rate of 50 mg /day for children between the age of 1 and <6 year, the amount of dust that a child would ingest in order to exceed the recommended tolerable daily intake TDI was also calculated.Keywords: urban dust, potentially toxic elements (PTEs), oral ingestion, Abakaliki, tolerable daily intake (TDI

Approaches to study in higher education portuguese students: a portuguese version of the Approaches and Study Skills Inventory for Students (ASSIST)

This paper examines the validity of the Approaches and Study Skills Inventory for Students—short version (ASSIST; Tait et al. in Improving student learning: Improving students as learners, 1998), to be used with Portuguese undergraduate students. The ASSIST was administrated to 566 students, in order to analyse a Portuguese version of this inventory. Exploratory factor analysis (principal axis factor analysis followed by direct oblimin rotation) reproduced the three main factors that correspond to the original dimensions of the inventory (deep, surface apathetic and strategic approaches to learning). The results are consistent with the background theory on approaches to learning. Additionally, the reliability analysis revealed acceptable internal consistency indexes for the main scales and subscales. This inventory might represent a valuable research tool for the assessment of approaches to learning among Portuguese higher education students

Exact exchange-correlation kernels for optical spectra of model systems

For two prototype systems, we calculate the exact exchange-correlation kernels fxc(x,x′,ω) of time-dependent density functional theory. fxc, the key quantity for optical absorption spectra of electronic systems, is normally subject to uncontrolled approximation. We find that, up to the first excitation energy, the exact fxc has weak frequency dependence and a simple, though nonlocal, spatial form. For higher excitations, the spatial behavior and frequency dependence become more complex. The accuracy of the underlying exchange-correlation potential is of crucial importance

Local density approximations from finite systems

The local density approximation (LDA) constructed through quantum Monte Carlo calculations of the homogeneous electron gas (HEG) is the most common approximation to the exchange-correlation functional in density functional theory. We introduce an alternative set of LDAs constructed from slablike systems of one, two, and three electrons that resemble the HEG within a finite region, and illustrate the concept in one dimension. Comparing with the exact densities and Kohn-Sham potentials for various test systems, we find that the LDAs give a good account of the self-interaction correction, but are less reliable when correlation is stronger or currents flow

Investigating the geochemical controls on Pb bioaccessibility in urban agricultural soils to inform sustainable site management

The solid-phase speciation of contaminants in soil plays a major role in regulating both the environmental mobility of contaminants and their bioavailability in biological receptors such as humans. With the increasing prevalence of urban agriculture, in tandem with growing evidence of the negative health impacts of even low levels of exposure to Pb, there is a pressing need to provide regulators with a relevant evidence base on which to build human health risk assessments and construct sustainable site management plans. We detail how the solid-phase fractionation of Pb from selected urban agricultural soil samples, using sequential extraction, can be utilised to interpret the bioaccessible fraction of Pb and ultimately inform sustainable site management plans. Our sequential extraction data shows that the Pb in our urban soils is primarily associated with Al oxide phases, with the second most important phase associated with either Fe oxyhydroxide or crystalline FeO, and only to a limited extent with Ca carbonates. We interpret the co-presence of a P component with the Al oxide cluster to indicate the soils contain Pb phosphate type minerals, such as plumbogummite (PbAl3(PO4)2(OH)5·H2O), as a consequence of natural “soil aging” processes. The presence of Pb phosphates, in conjunction with our biomonitoring data, which indicates the lack of elevated blood Pb levels in our gardeners compared to their non-gardening neighbours, suggests the (legacy) Pb in these soils has been rendered relatively immobile. This study has given confidence to the local authority regulators, and the gardeners, that these urban gardens can be safe to use, even where soil Pb levels are up to ten times above the UK’s recommended lead screening level. The advice to our urban gardeners, based on our findings, is to carry on gardening but follow recommended good land management and hygiene practices

Cell Wall Enzymes in Zygnema circumcarinatum UTEX 1559 Respond to Osmotic Stress in a Plant-Like Fashion

Fitzek E, Orton L, Entwistle S, et al. Cell Wall Enzymes in Zygnema circumcarinatum UTEX 1559 Respond to Osmotic Stress in a Plant-Like Fashion. FRONTIERS IN PLANT SCIENCE. 2019;10: 732.Previous analysis of charophyte green algal (CGA) genomes and transcriptomes for specific protein families revealed that numerous land plant characteristics had already evolved in CGA. In this study, we have sequenced and assembled the transcriptome of Zygnema circumcarinatum UTEX 1559, and combined its predicted protein sequences with those of 13 additional species [five embryophytes (Emb), eight charophytes (Cha), and two chlorophytes (Chl) as the outgroup] for a comprehensive comparative genomics analysis. In total 25,485 orthologous gene clusters (OGCs, equivalent to protein families) of the 14 species were classified into nine OGC groups. For example, the Cha+Emb group contains 4,174 OGCs found in both Cha and Emb but not Chl species, representing protein families that have evolved in the common ancestor of Cha and Emb. Different OGC groups were subjected to a Gene Ontology (GO) enrichment analysis with the Chl+Cha+Emb group (including 5,031 OGCs found in Chl and Cha and Emb) as the control. Interestingly, nine of the 20 top enriched GO terms in the Cha+Emb group are cell wall-related, such as biological processes involving celluloses, pectins, lignins, and xyloglucans. Furthermore, three glycosyltransferase families (GT2, 8, 43) were selected for in-depth phylogenetic analyses, which confirmed their presence in UTEX 1559. More importantly, of different CGA groups, only Zygnematophyceae has land plant cellulose synthase (CesA) orthologs, while other charophyte CesAs form a CGA-specific CesA-like (Csl) subfamily (likely also carries cellulose synthesis activity). Quantitative real-time-PCR experiments were performed on selected GT family genes in UTEX 1559. After osmotic stress treatment, significantly elevated expression was found for GT2 family genes ZcCesA, ZcCslC and ZcCslA-like (possibly mannan and xyloglucan synthases, respectively), as well as for GT8 family genes (possibly pectin synthases). All these suggest that the UTEX 1559 cell wall polysaccharide synthesis-related genes respond to osmotic stress in a manner that is similar to land plants