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In this review, we describe how the interplay among science, technology and community interests contributed to the evolution of four structural biology data resources. We present the method by which data deposited by scientists are prepared for worldwide distribution, and argue that data archiving in a trusted repository must be an integral part of any scientific investigation.
This study sought to develop frailty “identification rules” using population-based health administrative data that can be readily applied across jurisdictions for living and deceased persons. Three frailty identification rules were developed based on accepted definitions of frailty, markers of service utilization, and expert consultation, and were limited to variables within two common population-based administrative health databases: hospital discharge abstracts and physician claims data. These rules were used to identify persons with frailty from both decedent and living populations across five Canadian provinces. Participants included persons who had died and were aged 66 years or older at the time of death (British Columbia, Alberta, Ontario, Quebec, and Nova Scotia) and living persons 65 years or older (British Columbia, Alberta, Ontario, and Quebec). Descriptive statistics were computed for persons identified using each rule. The proportion of persons identified as frail ranged from 58.2-78.1 per cent (decedents) and 5.1-14.7 per cent (living persons).
Cranfield University's National Flying Laboratory Centre (NFLC) has developed a Bulldog light aircraft into a flight test facility. The facility is being used to research advanced in-flight instrumentation including fibre optic pressure and strain sensors. During the development of the test bed, Computational Fluid Dynamics (CFD) has been used to assist the flight test design process, including the sensor requirements. This paper describes the development of the Bulldog flight test facility, including an overview of the design and certification process, the in-flight data taken using the installed fibre optic sensor systems and lessons learned from the development programme, including potential further applications of the sensors.
The statistics of the velocity gradient tensor
, which embody the fine scales of turbulence, are influenced by turbulent ‘structure’. Whilst velocity gradient statistics and dynamics have been well characterised, the connection between structure and dynamics has largely focused on rotation-dominated flow and relied upon data from numerical simulation alone. Using numerical and spatially resolved experimental datasets of homogeneous turbulence, the role of structure is examined for all local (incompressible) flow topologies characterisable by
. Structures are studied through the footprints they leave in conditional averages of the
field, pertinent to non-local strain production, obtained using two complementary conditional averaging techniques. The first, stochastic estimation, approximates the
field conditioned upon
and educes quantitatively similar structure in both datasets, dissimilar to that of random Gaussian velocity fields. Moreover, it strongly resembles a promising model for velocity gradient dynamics recently proposed by Wilczek & Meneveau (J. Fluid Mech., vol. 756, 2014, pp. 191–225), but is derived under a less restrictive premise, with explicitly determined closure coefficients. The second technique examines true conditional averages of the
field, which is used to validate the stochastic estimation and provide insights towards the model’s refinement. Jointly, these approaches confirm that vortex tubes are the predominant feature of rotation-dominated regions and additionally show that shear layer structures are active in strain-dominated regions. In both cases, kinematic features of these structures explain alignment statistics of the pressure Hessian eigenvectors and why local and non-local strain production act in opposition to each other.
Obesity and type 2 diabetes lead to dramatically increased risks of atherosclerosis and CHD. Multiple mechanisms converge to promote atherosclerosis by increasing endothelial oxidative stress and up-regulating expression of pro-inflammatory molecules. Microvesicles (MV) are small ( < 1 μm) circulating particles that transport proteins and genetic material, through which they are able to mediate cell–cell communication and influence gene expression. Since MV are increased in plasma of obese, insulin-resistant and diabetic individuals, who often exhibit chronic vascular inflammation, and long-term feeding of a high-fat diet (HFD) to rats is a well-described model of obesity and insulin resistance, we hypothesised that this may be a useful model to study the impact of MV on endothelial inflammation. The number and cellular origin of MV from HFD-fed obese rats were characterised by flow cytometry. Total MV were significantly increased after feeding HFD compared to feeding chow (P< 0·001), with significantly elevated numbers of MV derived from leucocyte, endothelial and platelet compartments (P< 0·01 for each cell type). MV were isolated from plasma and their ability to induce reactive oxygen species (ROS) formation and vascular cell adhesion molecule (VCAM)-1 expression was measured in primary rat cardiac endothelial cells in vitro. MV from HFD-fed rats induced significant ROS (P< 0·001) and VCAM-1 expression (P= 0·0275), indicative of a pro-inflammatory MV phenotype in this model of obesity. These findings confirm that this is a useful model to further study the mechanisms by which diet can influence MV release and subsequent effects on cardio-metabolic health.
Finch trichomonosis, caused by Trichomonas gallinae, emerged in the Canadian Maritime provinces in 2007 and has since caused ongoing mortality in regional purple finch (Carpodacus purpureus) and American goldfinch (Carduelis tristis) populations. Trichomonas gallinae was isolated from (1) finches and rock pigeons (Columbia livia) submitted for post-mortem or live-captured at bird feeding sites experiencing trichomonosis mortality; (2) bird seed at these same sites; and (3) rock pigeons live-captured at known roosts or humanely killed. Isolates were characterized using internal transcribed spacer (ITS) region and iron hydrogenase (Fe-hyd) gene sequences. Two distinct ITS types were found. Type A was identical to the UK finch epidemic strain and was isolated from finches and a rock pigeon with trichomonosis; apparently healthy rock pigeons and finches; and bird seed at an outbreak site. Type B was obtained from apparently healthy rock pigeons. Fe-hyd sequencing revealed six distinct subtypes. The predominant subtype in both finches and the rock pigeon with trichomonosis was identical to the UK finch epidemic strain A1. Single nucleotide polymorphisms in Fe-hyd sequences suggest there is fine-scale variation amongst isolates and that finch trichomonosis emergence in this region may not have been caused by a single spill-over event.
Carbon nanotubes (CNTs) have unique thermal/electrical/mechanical properties and high aspect ratios. Growth of CNTs directly onto reactive material substrates (such as metals and carbon based foam structures, etc.) to create a micro-carbon composite layer on the surface has many advantages: possible elimination of processing steps and resistive junctions, provision of a thermally conductive transition layer between materials of varying thermal expansion coefficients, etc. Compared to growing CNTs on conventional inert substrates such as SiO2, direct growth of CNTs onto reactive substrates is significantly more challenging. Namely, control of CNT growth, structure, and morphology has proven difficult due to the diffusion of metallic catalysts into the substrate during CNT synthesis conditions. In this study, using a chemical vapor deposition method, uniform CNT layers were successfully grown on copper foil and carbon foam substrates that were pre-coated with an appropriate buffer layer such as Al2O3 or Al. SEM images indicated that growth conditions and, most notably, substrate surface pre-treatment all influence CNT growth and layer structure/morphology. The SEM images and pull-off testing results revealed that relatively strong bonding existed between the CNT layer and substrate material, and that normal interfacial adhesion (0.2‒0.5 MPa) was affected by the buffer layer thickness. Additionally, the thermal properties of the CNT/substrate structure were evaluated using a laser flash technique, which showed that the CNT layer can reduce thermal resistance when used as a thermal interface material between bonded layers.
When in March 1776 fast-riding couriers brought word to cities and towns up and down the American coast that the British had evacuated Boston, joy over the American success mixed with consternation over the whereabouts of the British fleet. Initial fears that the fleet had gone to attack another American port were allayed when news arrived that Halifax, Nova Scotia, was the destination. However, the Americans knew that the brothers Howe, General William and Admiral Richard, were not giving up, but rather licking their wounds and gathering strength before again descending upon the American coast.
A former bookseller and stationer, since the summer of 1775 Postmaster of New York, Ebenezer Hazard, was one of the first of Manhattan's inhabitants to hear the news of Boston's salvation and the British retreat to Halifax. For almost a year Hazard had been responsible for sending and receiving letters of the ‘eastern’ post that departed from and returned to New York City to and from the eastern colonies of Connecticut, Rhode Island, Massachusetts and New Hampshire. In the wake of the battles of Lexington and Concord in April 1775, accompanying the confusion that had erupted in the streets of New York between Whigs and Tories there had been a chaotic battle for control of the post; letters sent between New York and New England had been intercepted by different revolutionary committees along the way; thoughtful people had realized the necessity of a system to ensure the regular delivery of mail even in wartime.
Signs of normalcy returned to Boston in the wake of the British exodus in March 1776, including the resumption of Election Day, when inhabitants voted for town officers. This was always an occasion for one of Boston's native sons, Jeremy Belknap, to return to the city to experience the annual expression of the spirit of liberty, which was expressed more vociferously this year than usual. Belknap arrived on 1 June and stayed for ‘a lmost a week. He preached for Andrew Eliot, dined with friends, and saw the sights, which meant, of course, the signs of battle. He journeyed to Fort Hill, the eminence in Roxbury that looked out upon the Neck, to Dorchester Heights, and to Cambridge. After a week of catching up, feeling a sense of relief that Boston still stood with very few scars, Belknap returned to Dover. Summer in Dover involved household chores, such as gardening, to supplement the salt pork that typically dominated the family dinners. Belknap was constantly engaged in visiting the sick and widowed and presiding over burials, baptisms and marriages. He kept up with any war news coming out of Portsmouth, such as the launch a few weeks earlier of the ‘32 Gun frigate’, Raleigh. On 25 June and again a fortnight later he watched men train on the town green in preparation of joining an expedition to Canada.
Reverend Sir, – Some advices received by last post rendering it necessary for me to proceed as expeditiously as possible to Philadelphia, I am deprived of the pleasure of paying you a second visit as I intended, and laid under the necessity of sending Gorge's History to you, instead of delivering it in person, which, I doubt not, the necessity of the case will induce you to excuse.
Belknap did not receive the hastily sent message of his new friend Hazard until four days had passed, notwithstanding that Portsmouth was but ten miles downstream from Dover by boat – less as the crow flies. But it was winter, and there was war; nothing was in order, nothing passed for normal, and the letter received was like everything else – one's salary, a break in the weather, peace – much too late. And now Hazard was gone, riding slowly along post roads to the south, to Boston and beyond, to warmer regions than the deep woods of New Hampshire – though warmer not by much.
Upon Hazard's return to Portsmouth after his lengthy journey to Maine, he had found arrived at Postmaster Libbey's an express from Philadelphia calling the Surveyor of Post Roads south. Hazard and Belknap postponed discussing pages of Gorges's History; first there were effective communications to establish and a war to win.
The new year, 1781, found Hazard on the road and Belknap in bed. Indeed so sick was Belknap with rheumatism that after his letter of Christmas Day, 1780, he was not able to write for over two months. Hazard, meanwhile, was travelling towards Jamaica Plain and Dr Gordon's home when the New Year arrived. Such was his attention to business, however, that he was unable to write to Belknap until earlyFebruary.
Hazard wrote from Portsmouth, ten miles downriver from Dover; he apologized for not being able to visit his friend: ‘for however great my friendship for you is, as well as my anxiety for an interview with you, I cannot reconcile it with my conscience to go to Dover now’. Hazard was trying to drum up takers of tickets for a lottery sponsored by unnamed persons from the south involved in an unnamed scheme that Hazard was willing to term simply (and vaguely) ‘admiralty business’. Belknap (and others since then) had hardly a clue to what Hazard was referring; Belknap left well enough alone, and so shall we.
No, Hazard wrote, he was not in the business of ‘either love or matrimony’. Nor would he be for some time, so that ‘Mrs. B … will hardly be able to salute Mrs. H. before the war is over’. Until then, Hazard's love was history and science.
Upon being appointed postmaster general of the United States of America in 1782, Ebenezer Hazard designed a seal for the burgeoning postal service. Hazard, a classicist and a Greek scholar, chose as the symbol of the post office the Roman god Mercury, the messenger of the gods and patron of commerce and travel. Mercury stood for the activities and characteristics that Hazard and his contemporaries, the Americans attempting to win independence from Great Britain, most cherished. Hazard's role during the War of American Independence was that of a messenger. When the war began he was appointed postmaster for New York; when New York fell to the British in 1776 he earned the job of surveyor of post roads. He succeeded so well as surveyor – planning, maintaining, and securing post roads – that he was appointed postmaster general. Throughout this conflict Hazard, constantly ‘hurried through life on horseback’, anchored himself in the written word. He was, like all of his friends and contemporaries of culture and learning, a master of the epistle. His favourite correspondent, Jeremy Belknap, was also devoted to the epistler's art. The two men lived in different parts of the country, but being hungry to know all that was happening in war and government, took upon themselves the onus of being messengers to one-another, sending news and commentary – their own and that of others as well – whenever the post presented the opportunity.
Dear Sir, – This is the coldest day we have yet had, and, as I have no disposition to stir abroad, I shall devote part of it to you; though, as you tell me sometimes, I am not a letter in debt, excepting indeed the short script in which you told me you had found the Commentaries of De la Vega.
The world outside seemed motionless, without life. The Cocheco was hard frozen; feet of snow covered the ground. Conifers drooped from the weight of the snow. Sunlight, such as it was, appeared perfunctory. Indoors, however, the crackling warmth of the fireplace bespoke life and movement, keeping time with the pen conjuring up ideas and images of time and place. Belknap, lonely for the companionship of a fellow ‘son of science’, spent the afternoon as best he could.
‘We hear a talk of peace: doubtless you know more about it, for the news is said to come from your quarter’. Even in the depth of winter rumour and report went forth unimpeded. Belknap knew only of local, rather than national or international, political affairs. He found it simultaneously frustrating and entertaining that the New Hampshire legislature imposed a ‘test oath’, requiring conformity to Protestantism, upon office-holders; he viewed it ‘as a species of persecution for conscience’ sake’.
Exhilaration mixed with disappointment upon Belknap's return to Dover in the first week of August, 1784. The images and experiences of the White Mountains continued to engage his mind and occupy his emotions. The recollection of failure continually replayed in his thoughts. He wrote to his friend Hazard almost by way of confession:
My very dear Friend, – Last Saturday I returned from my journey, in which I encompassed the White Mountains and partly ascended the highest, which, being in an angle of 45°, proved rather too fatiguing for my thorax, and, after labouring for 2 hours, I was obliged to leave my company to pursue the ascent, which they accomplished in about 3 hours more.
Belknap, writing from Portsmouth, where he had gone to pick up his mail, among other things, promised to write about the journey at large when he returned to Dover and felt settled. In the meantime he sympathized with his friend's sufferings with gout. He had himself likewise suffered on the journey to the White Mountains. The pains of the temporal state taught Belknap not to have ‘such an opinion of long life in this world as some people are fond of entertaining’. According to Belknap, the best remedy for life in general and for gout in particular was ‘patience and flannel, my good friend’ – as well as, perhaps, ‘a piece of lean raw beef applied to the hands and feet when hard swelled, and shift ed every 12 hours’, which ‘will soften the skin and help the exudation of the morbific matter’.